Browse Topic: Lithium-ion batteries

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Performance based packaging standard for lithium batteries as cargo on aircraftAS6413 (Current)11/26/2025
This standard is intended to demonstrate and document the control of the potential hazards from lithium cells or batteries (UN 3090 and 3480) when transported as cargo on aircraft. [still need to identify if we are addressing global (external fire) or local (battery internal failures)] This standard addresses the need to control the hazards which might arise from a failure from an individual cell by containing the hazards within the package. This specific hazards addressed within this standard are: • Uncontrolled fire • Rapid overpressure pulse within compartment
G-27 Lithium Battery Packaging Performance
Recommendations and Background Material for Battery Package TestingAIR6840 (Current)11/26/2025
AS 6413 and slash sheets /1 & /2 hold the main information for testing of battery packaging. This document holds further information and expansion of philosophy, clarification etc. surrounding the testing and industry needs.
G-27 Lithium Battery Packaging Performance
CAM-7®/LTO Lithium-Ion Cells for Logistically Robust 6T Vehicle Batteries2024-01-362911/15/2024
ABSTRACT CAMX Power is developing Li-ion pouch cells and batteries based on its proprietary CAM-7® cathode material and commercially available lithium titanate (LTO) anode material to provide high power, high charging rate capability, long life, safety and configurational flexibility in military vehicle batteries. The CAM-7®/LTO technology can be discharged to 0 V with no loss in performance, has excellent tolerance for cell voltage reversal and cell overcharge as well as having excellent elevated-temperature storage stability, making it ideally suited for batteries that can be logistically managed with little or no maintenance or environmental controls. These same properties make CAM-7®/LTO technology well-suited for implementing in damage-tolerant, minimally managed, batteries that are structurally distributed and integrated in military vehicles.
Ofer, David, Kaplan, Daniel, Menard, Mark, Yang, Celine, Dalton-Castor, Sharon, McCoy, Chris, Barnett, Brian, Sriramulu, Suresh
Multifidelity Uncertainty Quantification in Battery Performance for eVTOL Flights Under Material and Loading UncertaintiesF-0080-2024-11675/7/2024
This study addresses safety concerns within the rapidly evolving Electric Vertical Takeoff and Landing (eVTOL) aircraft domain, focusing on efficient tools to quantify uncertainties in lithium-ion battery behavior - a critical aspect of eVTOL. One major issue with quantifying uncertainty is the prohibitive computational cost associated with many queries of an expensive-to-evaluate computational model. This work employs three physics-based battery models models of varying fidelity and cost to estimate the mean and the variance of the selected quantities of interest through a multifidelity method to reduce the computation cost. By combining information from multiple cheaper, lower-fidelity models through the Multifidelity Monte Carlo method, we significantly reduce the number of high-fidelity samples required for a prescribed mean-squared error, consequently reducing computational costs down to a tractable level. The proposed methodology is applied to estimate the mean and the variance of the battery temperature and voltage, accounting for uncertainties in flight conditions and materials. The first example focuses on a 580-second flight and is benchmarked against a standard Monte Carlo sampling technique. Results indicate a notable fourfold speed-up using the Multifidelity Monte Carlo method compared to the standard Monte Carlo method for the same mean-squared error for the voltage estimate. To showcase the method's generality, the multifidelity method is then applied to a longer flight of 3580 seconds for estimating the mean and the variance and utilizing these statistics to approximately estimate the probability of the flight completion. This demonstrates the adaptability of the methodology to various power profiles and considered uncertainties, with potential extensions to any battery chemistry. In conclusion, the presented multifidelity method offers a robust approach to enhance eVTOL safety by efficiently estimating uncertainties in battery behavior.
Diaz Flores Caminero, Alvaro, Kim, H. Alicia, Chaudhuri, Anirban, Guibert, Alexandre
Development of a Detailed 3D Finite Element Model for a Lithium-Ion Battery Subject to Abuse Loading2023-01-00074/11/2023
Lithium-ion batteries (LIBs) have been used as the main power source for Electric vehicles (EVs) in recent years. The mechanical behavior of LIBs subject to crush loading is crucial in assessing and improving the impact safety of battery systems and EVs. In this work, a detailed 3D finite element model for a commercial vehicle battery was built, in order to better understand battery failure behavior under various loading conditions. The model included the major components of a prismatic battery jellyroll, i.e., cathodes, anodes, and separators. The models for these components were validated against the corresponding material coupon tests (e.g., tension and compression). Then the components were integrated into the cell level model for simulation of jellyroll loading and damage behavior under three types of compressive indenter loading: (1) Flat-end punch, (2) Hemispherical punch and (3) Round-edge wedge. The comparisons showed reasonable agreement between modeling and experiments. With the validated numerical model, parametric studies were further performed to analyze the effect of separator anisotropy, to highlight its important role in the overall structural response of LIBs.
001-TestingSAE-PP-004369/24/2021
To reduce such pollution in the city area, zero emission fleet vehicles can be employed for a short distance goods transport. In current development, old pickup trucks are targeted as the vehicle to be converted to an electric vehicle. In this case, model based system design were employed to reduce the design cost and process time. Vehicle specification and the Modified and Simplified Federal Urban Driving (MSFUD) cycles were used as inputs to the MATLAB scripted program represented the models of EV components and the power flow in the system. Lithium Ion batteries and Hydrogen fuel cell system were also employed as the power sources for the electric propulsion. The simulation shows different scenarios that could be used as the decision making support information and EV design exploration. It can predict several various EV and fuel cell characteristics, such as driving range, performance, torque speed map, and motor power dynamics. The simulation study has shown, by comparison, employing fuel cell as the power sources will improve electric vehicle conversion of the pickup truck in terms of both performance and range in the long run.
Mutagaana, Festo
Battery TerminologyJ1715/2_202108 (Current)8/9/2021
This document contains definitions currently used in the automotive industry as they relate to energy storage and batteries for starting, lighting, and ignition applications, as well as for hybrid electric vehicles (HEV) and electric vehicles (EVs). It is intended that this document be a resource for those writing other battery, HEV, and EV documents, specifications, standards, or recommended practices. The use of the term “battery” in this document can be assumed to be a rechargeable battery (secondary battery). The terminology may be applied to other industries if desired.
Battery Terminology Committee
Recommended Practice for Determining Material Properties of Li-Battery Cathode Active MaterialsJ3021_202105 (Current)5/28/2021
This SAE Recommended Practice provides a set of test methods and practices for the characterization of lithium ion battery cathode active material. It is beyond the scope of this document to establish criteria for the test results, as these are usually established between the vendor and customer. It should be noted that materials properties can vary substantially between classes of materials (e.g., LNO and LFP) and caution should be exercised when attempting to directly compare their chemical and physical properties. While these distinctions are important for the manufacturer, this document focuses on the techniques to measure the materials properties and not their absolute or relative values. Future materials such as solid-state batteries and sulfides are beyond the scope of this document. It is beyond the scope of this document to examine the rheological properties of the cathode material dispersed in a coating slurry since such properties are influenced by the conductive additive, binder, and solvent, which are determined by the coating process. It is beyond the scope of this document to examine the electrochemical properties of cathode materials since these are influenced by electrode and ultimately cell design. Due to the difference in electrical and electrochemical properties of the cathode material, it is unrealistic to establish an electrode and cell design that would justly compare different cathode active materials.
Battery Materials Testing Committee
Battery Electric Vehicle Energy Consumption and Range Test ProcedureJ1634_202104 (Current)4/6/2021
This SAE Recommended Practice establishes uniform procedures for testing battery electric vehicles (BEVs) which are capable of being operated on public and private roads. The procedure applies only to vehicles using batteries as their sole source of power. It is the intent of this document to provide standard tests which will allow for the determination of energy consumption and range for light-duty vehicles (LDVs) based on the federal emission test procedure (FTP) using the urban dynamometer driving schedule (UDDS) and the highway fuel economy driving schedule (HFEDS) and provide a flexible testing methodology that is capable of accommodating additional test cycles as needed. Additionally, this SAE Recommended Practice provides five-cycle testing guidelines for vehicles performing supplementary testing on the US06, SC03, and cold FTP procedure. Realistic alternatives should be allowed for new technology. Evaluations are based on the total vehicle system’s performance and not on subsystems apart from the vehicle. NOTE: The range and energy consumption values specified in this document are the raw, test-derived values. Additional corrections are typically applied to these quantities when used for regulatory purposes (corporate average fuel economy, vehicle labeling, etc.).
Light Duty Vehicle Performance and Economy Measure Committee
2.0.102 - Model Based System Design of Urban Fleet Electric Vehicle ConversionSAE-PP-002122/1/2021
To reduce such pollution in the city area, zero emission fleet vehicles can be employed for a short distance goods transport. In current development, old pickup trucks are targeted as the vehicle to be converted to an electric vehicle. In this case, model based system design were employed to reduce the design cost and process time. Vehicle specification and the Modified and Simplified Federal Urban Driving (MSFUD) cycles were used as inputs to the MATLAB scripted program represented the models of EV components and the power flow in the system. Lithium Ion batteries and Hydrogen fuel cell system were also employed as the power sources for the electric propulsion. The simulation shows different scenarios that could be used as the decision making support information and EV design exploration. It can predict several various EV and fuel cell characteristics, such as driving range, performance, torque speed map, and motor power dynamics. The simulation study has shown, by comparison, employing fuel cell as the power sources will improve electric vehicle conversion of the pickup truck in terms of both performance and range in the long run.
Mutagaana, Festo
Measuring Properties of Li-Ion Battery ElectrolyteJ3042_202101 (Current)1/27/2021
This SAE Recommended Practice provides a set of test methods for characterizing lithium-ion battery electrolytes. These test methods are applicable to existing electrolyte materials and allow different facilities to conduct testing in a common manner. Solid electrolytes are expected to be commercially used for large scale batteries in the future. However, characterizing solid electrolytes may require methods different from those contained in this document. Such methods are not addressed in this document. It is not within the scope of this document to establish acceptance criteria for test results, as this is usually established between the vendor and customer. It is also not within the scope of this document to examine the electrochemical properties of an electrolyte, since these are influenced by electrolyte composition. In addition, establishing an electrolyte composition appropriate for all applications is not feasible.
Battery Materials Testing Committee
Hybrid and Electric Vehicle Safety Systems Information ReportJ2990/2_202011 (Current)11/4/2020
This information report provides an overview of a typical high voltage electric propulsion vehicle (xEV) and the associated on-board safety systems typically employed by OEM’s to protect these high voltage systems. The report aims to improve public confidence in xEV safety systems and dispel public misconceptions about the likelihood of being shocked by the high voltage system, even when the vehicle has been damaged. The report will document select high voltage systems used for xEV’s and describe safety systems employed to prevent exposure to the high voltage systems.
Hybrid - EV Committee
Maintenance of Batteries and Battery Charging and Servicing FacilitiesAIR1898A (Current)9/23/2020
This SAE Aerospace Information Report (AIR) covers, and is restricted to, hands-on servicing/ maintenance of industrial lead acid batteries used solely for motive power and exclusively for ground support equipment (GSE). It does not address or pertain to automotive-type SLI (starting-lighting-ignition) batteries or any other types of batteries (such as nickel-cadmium, zinc, or lithium batteries) which may be on-board airport GSE for either motive power or auxiliary uses. Similarly, the battery servicing and charging facilities described herein are those intended exclusively for industrial lead acid batteries.
AGE-3 Aircraft Ground Support Equipment Committee
Survivor Locator LightsAS4492A (Current)8/25/2020
This document covers survivor locator lights as follows: a Steady type lights (Type I) b Flashing-type lights (Type II)
S-9A Safety Equipment and Survival Systems Committee
Aviation Visual Distress Signals (AVDS)AS5134C (Current)8/25/2020
This SAE Aerospace Standard (AS) provides minimum performance and design standards for a handheld, high-intensity, flashing Aviation Visual Distress Signal (AVDS) based on light-emitting-diode (LED) technology operating simultaneously in visible (white) and near infrared (NIR) spectra designed to facilitate location and rescue of aviation accident/ditching survivors in open sea conditions.
S-9A Safety Equipment and Survival Systems Committee
Battery Management Systems for Rechargeable Lithium Batteries Used in Aerospace StandardsAIR6897 (Current)8/20/2020
This AIR provides basic background information and guidance for design and development of BMS architectures to be used in RLBs for aerospace applications. This guidance applies to batteries that are considered “installed” equipment and are intended to be part of the original or supplemental type certification or military airframe qualification.
AE-7D Aircraft Energy Storage and Charging Committee
Modern Battery Systems – the eMobility Enabler Virtual Pre-Conference CertificationC20178/7/2020
eMobility presents enormous challenges to engineers who have been engaged primarily in non-electrical sectors of vehicle engineering. Yet, eMobility also presents exciting opportunities to those who are ready to understand how high voltage batteries contribute to the success of eMobility. This seminar will bring together all the materials in an easy to follow format geared to a wide range of participants from engineers to technicians to sales staff to executives. To grasp the opportunities, we need to understand a small number of topics that describe how a battery system contributes to eMobility applications. However, that is only one aspect of how to develop a successful product. As the history of automotive engineering has demonstrated in the marketplace time after time, if the customer is not satisfied with the product, success will be elusive. This seminar will take us, in a team-based problem-solving session, through what we think the customer needs and wants are. As importantly, we’ll look at who the customers are and how that influences their wants and needs. Once these requirements are established, we can cover how cells behave, what materials are used in them and how they need to be handled. All of these are then important factors in cell design and battery design to support the expected levels of performance in energy and power. A lithium ion battery’s sensitivity to its environment and how to manage that sensitivity will also be explored. We will also look at the need to keep all cells performing together rather than as individuals. Another team-based exercise will examine one of the key concerns for consumers – range anxiety. We will explore how range can be estimated and what sensitivities drive this calculation. If range anxiety is a key issue still today, when will it not be so. We’ll look at what can be expected in battery performance beyond today in areas such as solid state, lithium sulfur and others. As important as skillful battery design is, it is just as important to verify that the battery will indeed, perform as promised in the specifications. Verification comes through a through a thorough testing program structured as part of the APQP (Advanced Product Quality Planning) disciplines. We will look at what is contained in such a test program and the regulations and standards that drive the tests. We’ll look at what makes up the safety and abuse test program of lithium ion batteries. We will look at media reports of electric vehicle fires in context of expectations of lithium ion batteries as a part of electric vehicle safety. The hazards that can be expected when working with high voltage lithium ion batteries will be examined and related to the management of the associated risks. The hazards will be related to the sensitivities of lithium ion cells and what can cause these hazards in a team-based session. We will look at common practices to measure and manage the risks in the various environments such as manufacturing, assembly, installation, R&D, testing fault detection, repair, disassembly and undefined states. No battery will be commercially successful if it is not cost competitive. On this subject we will examine product cost and its constituents such as material costs, overhead costs, labour costs and legacy costs. The three-day session will include short quizzes at key points as well as a post seminar short question set. In addition, early registrants are invited to submit battery technology related problems which will be used to pose a team-based challenge to be solved on the afternoon of the last day of the seminar. By attending this seminar, you will be able to: Identify the handling risks of the battery system Respect the risks and work with them Develop a safety program to manage the risks Capture customer wants and expectations of the battery system Identify factors that drive power and energy requirements Determine test program structure Compare and contrast the newest relevant battery technologies Calculate estimates of electric range and quantify the assumptions Critically assess media claims of new battery discoveries CEUs
Portable Emergency Lighting Systems for Flight Crew MembersARP1798B (Historical)7/14/2020
The purpose of this SAE Aerospace Recommended Practice (ARP) is to recommend general design and performance characteristics for hand-held portable, emergency lighting systems (note: the portable portion of this system that contains the lamp and reflector will be identified throughout the remainder of this document simply as a “flashlight”) intended for use by crew members of commercial aircraft during any emergency situation, within or outside of the aircraft cabin, where emergency lighting is required.
A-20C Interior Lighting - Test
2021 Mustang Mach-E20AUTP08_017/1/2020
Ford's first dedicated electric platform reveals the challenges and opportunities in developing a state-of-the-art EV. The 2021 Ford Mustang Mach-E is an all-new vehicle. It's Ford's first dedicated battery electric vehicle (BEV) and it's built on an all-new electric vehicle (EV) platform. If that wasn't enough pressure on its development team, the Mach-E also leverages the Mustang nameplate traditionally reserved for iconic sports coupes and serves as a technology flagship debuting a host of new features to expand convenience and safety. One of the lead engineers has likened it to simultaneously engineering an EV, a cellphone and an SUV. “You're delivering the vehicle, that's old-school stuff, we created that at Ford. Now we've got to deliver the new-school stuff too,” explained Robert Iorio, vehicle engineering manager for the Mustang Mach-E.
Seredynski, Paul
Recommended Practices for Shipping Transport and Handling of Automotive-Type Battery System - Lithium IonJ2950_202006 (Current)6/9/2020
This SAE Recommended Practice (RP) aids in the identification, handling, and shipping of lithium batteries to and from specified locations. It is the specific intent of this RP to identify, utilize, and reference existing U.S. and international hazardous materials (dangerous goods) transportation regulations, which are the only methodologies to be used to establish transportability. It is also the intent of this RP to provide recommendations to be used by service and shipping personnel for the purpose of determining a possibly damaged/defective battery’s transportability. In support of the service and shipping personnel, these recommendations seek to use standard tools of the trade and avoid laboratory type equipment.
Battery Transportation Committee
48 V High-power Battery Pack for Mild-Hybrid Electric Powertrains2020-01-04414/14/2020
Mild hybridisation, using a 48 V system architecture, offers fuel consumption benefits approaching those achieved using high-voltage systems at a much lower cost. To maximise the benefits from a 48 V mild-hybrid system, it is desirable to recuperate during deceleration events at as high a power level as possible, whilst at the same time having a relatively compact and low cost system. This paper examines the particular requirements of the battery pack for such a mild-hybrid application and discusses the trade-offs between battery power capabilities and possible fuel consumption benefits. The technical challenges and solutions to design a 48 V mild-hybrid battery pack are presented with special attention to cell selection and the thermal management of the whole pack. The resulting battery has been designed to achieve a continuous-power capability of more than 10 kW and a peak-power rating of up to 20 kW. The pack has been built and has been subjected to a series of tests at a range of ambient temperatures. The performance of the pack has been validated and the main characteristics, such as the internal resistance and capacity have also been established. The performance targets for the pack have been achieved. Further testing is underway to fully characterize the pack’s capabilities and characteristics, after which it will be installed into MAHLE’s 48 V eSupercharged demonstrator car.
Hall, Jonathan, Borman, Stephen, Hibberd, Benjamin, Bassett, Michael, Reader, Simon, Berger, Martin
Dynamic Simulation for LFP Pouch Batteries Coupled Mechanics-Electrics-Thermodynamics under Mechanical Abuse2020-01-13324/14/2020
The safety design of batteries, an important part in passive safety development of electric vehicle, is difficult in practical project application because of complex structure inside and Multi-physics reactions coupled mechanics-electrics-thermodynamics under mechanical abuse. An efficient computational model of batteries that can be attached to model of vehicle used for collision simulation is needed. In this work, four types of Multi-physics battery models (detailed computational model, simplified representative-sandwich model, composite layered model and simplified layered model) of pouch cell with LiFePO4 system are established in a commercial finite element software LS-DYNA (usually used for vehicle collision simulation). And the difficulties of modeling, resource demanded for calculation, accuracy of results (in mechanics, electrics and thermodynamics) in the four models are compared. In detail, based on quasi-static mechanical experiments of positive and negative current collectors, current collectors with active materials and separators, the corresponding constitutive models and material cards are established. And a one-way coupling methodology is adopted for the Multi-physics simulation. We use the thickness deformation of separators and distance between positive and negative current collectors in one circuit achieved from the dynamic indentation experiment as the criteria for short-circuit. The mechanical simulation predicts the deformation of battery cell. The electrical and thermal simulation predicts resistive heating problems after short-circuit onset and propagation of heat in the whole cell. Results show that these models can describe battery behavior from deformation to thermal propagation under dynamic mechanical abuse well. And an efficient method to simplify models of battery cell for engineer application of battery-package or vehicle simulation is present in the end
ZHANG, Ruiyu, Wang, Tao, Deng, Chenghao, Jin, Guoqing, Xiao, Heping, Zhang, Yanbing
Thermal Analysis of a Magnetic Contactor in Electric Vehicle Li-Ion Battery Packs2020-01-13454/14/2020
In this paper, we perform 3D numerical simulations to understand the thermal operation of a high-current-load DC Magnetic Contactor (MC) within a Li-ion battery pack. The main focus is on evaluating the thermal behavior of an electronically controlled MC through a parametric study that investigates the effect of the magnitude of electric current with the corresponding Ohmic heat generation of the MC. For the numerical analysis we perform time-accurate, conjugate heat transfer-based 3D CFD simulations on high spatial resolution grids with commercial CFD software STAR-CCM+. The results of the numerical simulations with temperature dependent material properties are validated against experimental temperature measurements at various locations on the outer body of the MC. The spatial distribution of temperature, and current within the MC and its connected components are also computed for various input parameter values to evaluate a range of its operational validity within an automotive Li-ion battery pack.
Pulugundla, Gautam, Galvan, Karlo, Dubey, Prahit
Parameter Determination for the Battery Equivalent Circuit Model Using a Numerical Integro-Differential Method2020-01-11794/14/2020
The battery equivalent circuit model consisting of an open circuit voltage (OCV) source and a resistor in series with parallel resistor-capacitor (RC) elements is widely used in system-level simulation. The accuracy of the transient I-V characteristics of the battery model strongly relies on the values of the RC parameters prescribed in the circuit. One of the solutions for determining RC parameters is curve-fitting the measurement data of the battery voltage in the relaxation period obtained from a charge or discharge current pulse test. Since the equation used for curve-fitting can be expressed as the sum of multiple exponential functions which are nonlinear with respect to the RC parameters, the nonlinear least-square (LS) algorithm shows poor performance or even fails due to its sensitiveness to initial guesses of the solutions. One approach that makes use of the unique feature of the sum of two exponentials reformulates the nonlinear voltage equation to a linear one and calculates out the RC parameters using the linear LS algorithm. However, the approach cannot be applied to the model with more than two RC elements. In this work, an integro-differential method is applied to the nonlinear problem arisen from curve-fitting the RC parameters. As a result, the nonlinear equation containing the sum of multiple exponential functions can be linearized. An application example demonstrates that the LS algorithm applied to the resulting linear equation shows no sensitivity to the initial conditions and good accuracy can be achieved.
Chen, Chao
The Effect of Driver's Behavior and Environmental Conditions on Thermal Management of Electric Vehicles2020-01-13824/14/2020
Worldwide projections anticipate a fast-growing market share of the battery electric vehicles (BEVs) to meet stringent emissions regulations for global warming and climate change. One of the new challenges of BEVs is the effective and efficient thermal management of the BEV to minimize parasitic power consumption and to maximize driving range. Typically, the total efficiency of BEVs depends on the performance and power consumption of the thermal management system, which is highly affected by several factors, including driving environments (ambient temperature and traffic conditions) and driver's behavior (aggressiveness). Therefore, this paper investigates the influence of these factors on energy consumption by using a comprehensive BEV simulation integrated with a thermal management system model. The vehicle model was validated with experimental data, and a simulation study is performed by using the vehicle model over various traffic scenarios generated from a traffic simulator. Particularly, the aggressiveness of a human driver is emulated by varying parameters in the intelligent driver model.
Kim, Jaewoong, Rodriguez, Rodolfo, Kwak, Kyoung Hyun, Jung, Dewey, Kim, Youngki
Sensorless Individual Cell Temperature Measurement by Means of Impedance Spectroscopy Using Standard Battery Management Systems of Electric Vehicles2020-01-08634/14/2020
Lithium ion technology is state of the art for actual hybrid and electrical vehicles. It is well known that lithium ion performance and safety characteristics strongly depend on temperature. Thus, reliable temperature measurement and control concepts for lithium ion cells are mandatory for applications in electrical cars. Temperature sensors for all individual cells increase the battery complexity and cost of a battery management system. Normally, temperature is measured on module level in current battery packs, without observation of the individual cell temperature. Sensorless cell impedance-based temperature measurement concepts have been published and are validated in laboratory studies. Dedicated test equipment is usually applied, which is not useful for automotive series application. This work describes a practical approach to enable impedance-based sensorless internal temperature measurement for all individual cells using state-of-the art battery management system components. Excitation is generated by DC to DC converters of a standard commercial active balancing systems. For data acquisition, also an established commercial battery monitoring circuit unit is used. To overcome bandwidth limitations, a sub-sampling scheme is presented, which allows to determine the impedance at higher frequencies than the sampling rate. Impedance calculation is performed by means of efficient digital signal processing concepts with low demand on memory and processing power. Thus, the method can be integrated into existing battery management systems with low implementation effort. The concept is demonstrated on a 4-cell submodule of 26 Ah automotive Li-ion cells. It can also be applied in low-cost battery management systems without active balancing capability.
Haussmann, Peter, Melbert, Joachim
Mechanical Response of Laterally-Constrained Prismatic Battery Cells under Local Loading2020-01-02004/14/2020
The crash safety of lithium-ion batteries has received great attention in recent years because of their growing popularity in electric vehicles. However, the safety issues of prismatic batteries have not been thoroughly studied; in particular, the mechanical responses of prismatic battery cells with lateral constraints under varied loading conditions still remain unclear. In this study, indentation tests are conducted to study the mechanical response of prismatic battery cells. Fixtures providing lateral constraint which simulates the real packing situation in battery module are designed. Firstly, the effects of lateral constraints on coupled mechanical and electrical responses of prismatic battery cells are analyzed and discussed. Secondly, dynamic indentation tests of prismatic cells with lateral constraints are carried out. The response of the stacked batteries under local loading is revealed. Thirdly, non-destructive X-ray computed tomography imaging technique is employed to detect the fracture patterns in battery cells caused by indentation. The results of indentation tests indicate that the indentation depth and the peak force for the battery internal failure are affected by the side constraint conditions and the responses of battery cells vary under different loading speeds. Also, the XCT scanning results of the samples clearly show the different levels of internal damage and fracture patterns under varied conditions. The detailed mechanical responses of the prismatic battery cell disclosed in the present study can provide support for modeling and protection of batteries under side impact.
Xiao, Feiyu, Xing, Bobin, Xia, Yong
Parameter Optimization of Two-Speed AMT Electric Vehicle Transmission System2020-01-04354/14/2020
At present, many electric vehicles are often equipped with only a single-stage final drive. Although the single-stage speed ratio can meet the general driving requirements of electric vehicles, if the requirements of the maximum speed and the requirements for starting acceleration or climbing are met at the same time, the power demand of the drive motor is relatively large, and the efficient area of the drive motor may be far away from the operating area corresponding to daily driving. If the two-speed automatic transmission is adopted, the vehicle can meet the requirements of maximum speed, starting acceleration and climbing at the same time, reduce the power demand of the driving motor, and improve the economy under certain power performance. This is especially important for medium and large vehicles. Therefore, this paper considers that the working torque and speed of the motor can be changed by optimizing the speed ratio of the transmission and changing the gear position so that the motor can work more in the high-efficiency zone. Taking an electric logistics vehicle with a drive motor & two-speed AMT power transmission system as the research object, this paper takes the vehicle’s power performance requirements and AMT design requirements as constraints, and the vehicle energy consumption and driving range as the optimization objective, and adopts generic algorithm to optimize the parameters of the transmission system. Then, a complete vehicle model was built with software to verify the energy consumption of the vehicle, so as to verify the advantages of the two-gear transmission scheme. The results show that compared with the single-gear transmission scheme, the optimized two-gear transmission scheme improves the vehicle’s power performance and economy, and reduces the demand for motor power and torque.
Cui, Jian, Tan, Gangfeng, Feng, Jia'ao, Tian, Zhongpeng, Agyeman, Philip
Research on the Performance of Battery Thermal Management System Based on Optimized Arrangement of Flat Plate Heat Pipes2020-01-01624/14/2020
The thermal management system is essential for the safe and long-term operation of the power battery. The temperature difference between the individual cells exceeds the acceleration of the battery performance, which leads to battery out of use and affects the performance of the vehicle. Compared with the low heat transfer coefficient of the air-cooling system, the complex structure of the liquid-cooling system and the large quality of phase change material system, the heat pipe has high thermal conductivity, strong isothermal performance and light weight, it’s an efficient cooling element that can be used for thermal management. In this study, the flat plate heat pipe(FPHP) is used to manage the temperature of the battery, through experiments, the optimized placement of the flat heat pipe is obtained. Based on this, the thermal performance of the thermal management system is studied, thus achieve the purpose of reducing the maximum temperature of the batteries and balancing the temperature difference between batteries. In this paper, a square LiFePO4 battery pack is taken as the object, and the battery heat generation-heat transfer-heat dissipation is the main line. Firstly, the battery heat generation model is established according to the thermal characteristics of the battery, and then based on the heat transfer characteristics of the FPHP, establish the heat transfer model of FPHP. Then the thermal management performance of the battery pack under the conditions with and without FPHP was studied by different discharge magnifications experiments. By comparing with simulation results and the natural cooling results, the superiority of the flat heat pipe at different discharge rates was obtained. Studies have shown that this thermal management system keeps the cell temperature difference within 3 °C. Used in electric vehicles, it provides reference and support for future thermal management of high-power batteries.
Zheng, Xingmang, Tan, Gangfeng, Sun, Meng, Zhou, Fangyu, Liu, ZhiQiang
SOC Estimation Based on an Adaptive Mixed Algorithm2020-01-11834/14/2020
SOC (State of charge) plays an important role in vehicle energy management, utilization of battery pack capacity, battery protection. Model based SOC estimation algorithm is widely regarded as an efficient computing method, but battery model accuracy and measuring noise variance will greatly affect the estimation result. This paper proposed an adaptive mixed estimation algorithm. In the algorithm, the recursive least squares algorithm was used to identify the battery parameters online with a second-order equivalent circuit model, and an adaptive unscented Kalman method was applied to estimate battery SOC. In order to verify the effect of the proposed algorithm, the experimental data of a lithium battery pack was applied to build a simulation model. The results show that the proposed joint algorithm has higher estimation accuracy and minimum root mean square error than other three algorithms.
Huang, Denggao, Zhu, Zhongwen, Liu, Zhihong, Wang, Xu, Li, Cheng, Liu, Runqin
Lithium-Ion Battery Cell Modeling with Experiments for Battery Pack Design2020-01-11854/14/2020
Lithium-ion polymer battery has been widely used for vehicle onboard electric energy storage ranging from 12V SLI (Starting, Lighting, and Ignition), 48V mild hybrid electric, to 300V battery electric vehicle. Formulation on cell parameters acquired from minimum numbers of experiments, the modeling and simulation could be an effective approach in predicting battery performance, thermal effectiveness, and degradation. This paper describes the modeling, simulation, and validation of Lithium-Nickel-Manganese-Cobalt-Oxide (LiNiMnCoO2) based cell with 3.6V nominal voltage and 20Ah capacity. Constant current 20A, 40A, 60A, and 80A discharge tests are conducted in the computer-controlled cycler and temperature chamber. Discharging voltage curves and cell surface temperature distributions are recorded in each discharging test. A three-dimensional cell model is constructed in the COMSOL multi-physics platform based on the cell parameters. The model validation is performed by experimental discharging voltage curves and cell surface temperature data. Simulated data matches the experiments with acceptable discrepancy. As a cell is the building block to form high-voltage battery module and pack, the developed cell model could play an important role in battery pack development and design.
Liu, Yiqun, Liao, Y. Gene, Lai, Ming-Chia
Effects of Using an Electrically Heated Catalyst on the State of Charge of the Battery Pack for Series Hybrid Electric Vehicles at Cold Start2020-01-04444/14/2020
Battery models are being developed as a component of the powertrain systems of hybrid electric vehicles (HEVs) to predict the state of charge (SOC) accurately. Electrically heated catalysts (EHCs) can be employed in the powertrains of HEVs to reach the catalyst light off temperature in advance. However, EHCs draw power from the battery pack and hence sufficient energy needs to be stored to power auxiliary components. In series HEVs, the engine is primarily used to charge the battery pack. Therefore, it is important to develop a control strategy that triggers engine start/stop conditions and reduces the frequency of engine operation to minimize the equivalent fuel consumption. In this study, a battery pack model was constructed in MATLAB-Simulink to investigate the SOC variation of a high-power lithium ion battery during extreme engine cold start conditions (-7°C) with/without application of an EHC. The EHC was simulated in MATLAB to determine the energy required to heat the catalyst during cold start conditions. The effect of the EHC in emissions purification at -7°C was studied using a three-way catalyst (TWC) model. The EHC was operated only during the initial few seconds before the engine start to increase the bed temperature of the catalyst. This was found to have a significant impact on exhaust gas emissions even under cold start conditions. However, powering the EHC lowered the SOC of the battery pack, triggering the engine to run and consume more fuel. Hence, an engine ON/OFF control strategy was proposed to control the engine operation conditions and effectively charge the battery pack. The SOC variation of the battery pack and the effects on emissions and fuel consumption were simulated and compared with/without the EHC. The battery model was validated with a control strategy proposed in simulations at 23°C and a parameter study was conducted at -7°C.
Sivakumar, Suchitra, Shingyouchi, Hajime, Yan, Xieyang, Okajima, Toshinori, Yamaguchi, Kyohei, Kusaka, Jin, Nagata, Makoto
Numerical Modeling of Lithium-Ion Battery Cells and Modules Subjected to Low Speed Indentation2020-01-04514/14/2020
Lithium-ion (or Li-ion) battery systems are being increasingly used as the main power source in new generation hybrid and electric vehicles. Their mechanical integrity under abuse loading conditions is very important for vehicle safety design. In this research, a computational study was performed to simulate mechanical tests on vehicle battery cells and modules. The tests were conducted on commercial Li-ion battery cells and entire modules at low speed using a high capacity material testing system. Based on loading and boundary conditions during the tests, finite element (FE) models using the explicit FEA solver LS-DYNA, were developed. The model predictions demonstrated reasonable agreement in terms of failure modes and force-displace response at both cell and module levels. With this newly developed numerical model for the entire battery module, a parametric study was performed to investigate the effect of small design modifications on its overall behavior subject to punch penetration.
Zhu, Feng, Du, Xianping, Lei, Jianyin, Audisio, Lorenzo, Sypeck, David
History and Prospects for Electric Vehicles and Electric Bikes: Pathway to Sustainable Carbon Free Energy and Transportation2020-01-09744/14/2020
The Electric Transportation Revolution (ETR) began with the General Motors USA EV1 project and Yamaha Japan Pedal Assist System (PAS) electric bike, both in 1993. Worldwide EB annual sales are 40 million with 300 million on the road, mostly in China. Mandates and government incentives influence the EV market, customer demand drives EB growth. The EPA CO2 endangerment finding is forcing the auto industry to invest in EVs to help limit Mankind Made Carbon Dioxide Climate Change, MMCDCC, which is based on theoretical computer models that calculate global temperature. Measured temperature data, revised by modelers, used to validate these models has been challenged and so reported. Historical climatology data shows that Natural Climate Change, NCC, is more likely the CC cause. Known periodic variations of the sun’s orbit changes solar radiance and causes NCC. More CO2 in the atmosphere produces more plant growth, more food, thus CO2 is a beneficial gas. We propose a long term pathway to eliminate CO2 as an issue for energy and transportation. Fossil fuels may be depleted in 200 years. During this period, transition worldwide to nuclear power and hydrogen for electricity and transportation is necessary. Nuclear fuels will be used forever as uranium extraction from seawater is now possible and is replenished by runoff from land. Nuclear electricity will produce hydrogen from electrolysis of water for vehicle use. Power plants and vehicles will thus not produce CO2. With this prospect of sustainable carbon free electricity and vehicle fuel, the humanitarian thing to do today is to continue to use fossil fuels for both domains, in order to provide affordable heat in cold winters and cooling in hot summers which occurs in some regions of the world today until nuclear options are developed. This all is likely NCC as it has been for hundreds of millions of years on planet earth, and not MMCDCC.
Jamerson, Frank E.
Evaluation of External Short-Circuit Safety of NCM/C Li-Ion Power Battery under Different State of Health2020-01-04544/14/2020
With the increasing frequency of fire incidents of electric vehicles, the safety of power batteries has attracted more and more attention. At present, the research on the safety of power batteries is mainly focused on fresh batteries. As the state of health of batteries deepens, how the safety of the battery evolves is not clear enough so far. This paper analyzes the external short-circuit safety of a NCM/C rectangular battery under different state of charges. The results show that when the cycle number is less than 800, the maximum temperature of the battery during short-circuit is below 130 °C. The main failure mode of the battery is bulging in volume or opening of the explosion-proof valve and there is no obvious regularity between the failure mode with the cycle life. However, when the cycle number reaches 1000, the battery goes into thermal runaway during the safety test. In specific, the explosion-proof valve opens, and a large amount of smoke is sprayed, and the surface temperature of the battery reaches 350 °C with obvious burn marks. The research in this paper shows that when the battery ages to 85% state of health, its external short-circuit safety may have some inflection point, and its safety will be significantly degraded. Special attention should be paid to the safety of the aged batteries in operation.
Liu, Lei, Lin, Chunjing, Yang, Peixia, Wang, Fang, Fan, Bin
Methods for Leak Testing Lithium-Ion Batteries to Assure Quality with Proposed Rejection Limit Standards2020-01-04484/14/2020
A method is presented discussing how to reliably and quantitatively detect leakage from battery cells through the detection of escaping liquid electrolyte vapors, typically dimethyl carbonate (DMC). The proposed method does not require the introduction of an additional test gas into battery cells. The test system, which is non-destructive in nature, is applicable to non-rigid pouch cells and rigid prismatic or cylindrical cells. Lithium-ion batteries are a more suitable energy source for many applications because of their high energy density and low self-discharge rate. In the automotive powertrain sector, the lithium-ion battery market share is growing rapidly, with particularly high demand being placed on battery service life and safety. Requirements regarding maximum cell temperature, electrical load power or discharge power of the cell can be controlled by cooling and power management of the battery cell. A single defect in a cell housing can only be detected through leak detection of each battery cell. The lifetime of a battery strongly depends on the tightness of the cell housing, because of the harmful effects caused by the interaction between the electrolyte and water vapor. Rapid detection of leaks in the production of battery cells is absolutely essential to achieving necessary service life and safety requirements. This applies particularly to small leaks that cannot be detected immediately after the cell has been manufactured, for example by using an electrical discharge method. For pouch cells, no reliable method to detect small leak channels is available. This paper examines the spectrum of possible leak scenarios for cylindrical, prismatic and pouch lithium-ion batteries [Figure 1]. Currently no rejection limits have been codified for these batteries. INFICON has established empirically derived rejection limits that will be discussed in this paper.
Wetzig, Daniel, Reismann, Maximillian
Dynamic Load Identification for Battery Pack Bolt Based on Machine Learning2020-01-08654/14/2020
Batteries are exposed to dynamic load during vehicle driving. It is significant to clarify the load input of the battery system during vehicle driving for battery pack structural design and optimization. Currently, bolt connection is mostly applied for battery pack constraint to vehicle, as well as for module assembly inside the pack. However, accurate bolt load is always difficult to obtain, while directly force measurement is expensive and time consuming in engineering. In this paper, a precise data driven model based on Elman neural network is established to identify the dynamic bolt loads of the battery pack, using tested acceleration data near bolts. The dynamic bolt force data is measured at the same time with the acceleration data during vehicle running in different driving conditions, utilizing customized bolt force sensors. A data preprocessing method synthesizing Wavelet denoising method and machine learning algorithm is designed to improve model precision under dynamic condition. Parts of the pretreated acceleration and force data that obtained in various driving conditions are employed for model training, while the rest for model validation. Meanwhile, an index is introduced to quantitatively assess the identification accuracy against the measured force data. The identified loads show good consistency with the tested data. The error of the estimated bolt force result is within 20%. Finally, the reliability and generalization of the method are discussed. This method in this paper does not rely on prior known structural characteristics, and may be further developed for mechanical monitoring and diagnosis in battery modules in the future.
Liu, Ruixue, Hou, Zhichao, Wang, Shuyu, Sheng, Deke, Liu, Yuan
Trade-Off Analysis and Systematic Optimization of a Heavy-Duty Diesel Hybrid Powertrain2020-01-08474/14/2020
While significant progress has been made in recent years to develop hybrid and battery electric vehicles for passenger car and light-duty applications to meet future fuel economy targets, the application of hybrid powertrains to heavy-duty truck applications has been very limited. The relatively lower energy and power density of batteries in comparison to diesel fuel and the operating profiles of most heavy-duty trucks, combine to make the application of hybrid powertrain for these applications more challenging. The high torque and power requirements of heavy-duty trucks over a long operating range, the majority of which is at constant cruise point, along with a high payback period, complexity, cost, weight and range anxiety, make the hybrid and battery electric solution less attractive than a conventional powertrain. However, certain heavy-duty applications, such as Class 6-7 urban vocational trucks, can benefit from hybridization due to their transient operating profiles and relatively lower vehicle weight. While many studies have quantified the fuel consumption benefits of hybridization in this segment, very few studies have outlined the arduous process of selection and sizing of hybrid powertrain components based on the trade-offs between fuel consumption, payback period, cost, weight, packaging, emissions and aftertreatment temperature. To investigate the potential for electrification in heavy-duty applications, FEV has developed a system level approach for the selection and sizing of heavy-duty diesel hybrid powertrain components using GT-SUITE. The approach has been applied for a Class 6-7 urban vocational truck, which typically experiences low speed driving with frequent start-stops. A dynamic model for the baseline vehicle was developed and calibrated to test data that included, fuel efficiency, engine-out NOx, engine-out PM and aftertreatment system temperature. The model was then updated with hybrid powertrain components and evaluated over cycles developed for chassis dynamometer testing of heavy-duty vehicles, specifically the Heavy Heavy-Duty Diesel Truck (HHDDT) schedule and EPA Urban Dynamometer Driving Schedule (HDUDDS). In the evaluation, key trade-offs were identified between fuel consumption, initial cost, payback period, package size, emissions and vehicle weight. The trade-off analysis demonstrated that similar fuel consumption benefits with an identical payback period could be achieved with multiple hybrid powertrain configurations, however package size, initial cost and weight considerations determined the final optimum solution. The final hybrid powertrain configuration for a Class 6-7 urban vocational truck proposed from this study demonstrates a 20.7% fuel consumption reduction when comparing to the baseline vehicle and applying a two year payback period. In addition, the diesel hybrid powertrain configuration provides an 11% reduction in engine-out NOx emissions and an 86% reduction in engine-out PM emissions, while maintaining aftertreatment temperature of the baseline configuration.
Joshi, Satyum, Dahodwala, Mufaddel, Koehler, Erik W., Franke, Michael, Tomazic, Dean, Naber, Jeffrey
Extended Endurance Unmanned Aerial Vehicle via Structural Electrical Power Storage and Energy Generation Devices2020-01-00413/10/2020
As the application of unmanned aerial vehicles (UAV) have increased in the military, commercial and private sectors, special attention has been focused on improving upon high altitude long endurance (HALE) performance. Therefore, under a multi-year, multi-discipline senior project team comprised of Aerospace Engineering, Electrical Engineering, Computer Engineering, Mechanical engineering, and Chemical Engineering undergraduate teams, investigative and experimental research has begun into the substitution of various aircraft structural components with power storage and power generation devices used also as structure to improve flight endurance and performance capabilities of solar powered UAVs. One viable solution may be found in the reduction of the amount of parasitic weight due to the required power systems on board these types of aircraft. These power systems are usually found in the form of energy storage devices such as lithium polymer batteries and energy generation devices such as solar cells. This path led to the innovation of the ‘Flying Battery’. The ‘Flying Battery’ integrates various free energy generating devices such as structural solar cells, structural energy storage devices, thermo-electric generators, and vibration induced power generators to create a flying structure that will be more efficient overall. By weighting the design factors for the power systems by their structural strengths and stiffnesses, the power-to-weight ratio of the aircraft may be significantly improved in the long run while also enabling a structure that may withstand the various nominal and off-nominal aerodynamic loading conditions experienced during flight. This paper discusses the mission operations, methods of testing and the progress achieved thus far toward achieving potential endurance and efficiency increases in unmanned aerial vehicles. These will be done through laboratory and eventual model flight experiments of novel structural designs for graphene super-capacitors, solar cells, and other power generation devices.
Oetting, Geoffrey Smith
Multiple Sensors Aid in Development of an Electrical Vertical Takeoff and Landing AircraftTBMG-361573/1/2020
Beta Technologies (South Burlington, VT) has built a prototype Electrical Vertical Takeoff and Landing aircraft (eVTOL) and is putting it through the wringer. They are using wireless sensor systems from Parker LORD, MicroStrain® Sensing Systems (Williston, VT) to monitor the structures and functions of the prototype, both on a test stand and in flight.
Electrifying GM20AUTP03_013/1/2020
After two decades of hybrid development, General Motors puts its full futurepropulsion focus on BEV technology-with vertically integrated development and production. General Motors' long, convoluted journey toward vehicle electrification has finally arrived at an earlier-than-expected destination: total commitment to a battery-electric future. GM is officially “all in” on BEVs as its future propulsion strategy, with some 20 electric models slated for launch by 2023. The Detroit-Hamtramck plant is being transformed into GM's first dedicated EV production facility. Its product cadence, set to begin within the year, will be led by electric Chevrolet and Cadillac crossovers. Joining them is GM's first electric pickup that will resurrect the still-popular Hummer nameplate within the GMC brand. The company aims to sell one million EVs globally by 2026, asserts CEO Mary Barra, while it continues to evolve its profit-driving IC-powered trucks and crossovers (and develop self-driving vehicles with tech partner Cruise). It's an ambitious plan that ends GM's 20 years of hybrid-vehicle development. That extensive HEV roster included belt-alternator “electric assist” systems; “Two-Mode” transmissions co-developed with Daimler and BMW; 42-volt starter-generator pickup trucks and two generations of Volt range-extender hybrids that included Volt's Cadillac spinoff, the obscure ELR.
Robot Circulating Liquid Stores Energy and Provides PowerTBMG-360032/1/2020
Humans and other complex organisms manage life through integrated systems. Humans store energy in fat reserves spread across the body and an intricate circulatory system transports oxygen and nutrients to power trillions of cells. But with an untethered robot, things are much more segmented with batteries, motors, and cooling systems scattered throughout.
Replacement of a 50cc Two-stroke Engine with an Electric Powertrain2019-32-06231/24/2020
As global regulations look to create a dramatic reduction in CO2 emission and other forms of pollution, companies with products that rely on engine technology must be ready to take on the electrification challenge. Applications that remain using two-stroke engine technology continue to exist due to their very high power density requirements. However, their history of higher pollution compared to four-stroke engines makes them a target to be regulated out of existence. Such high power two-stroke applications include high performance off-road motorcycles. In this type of product, electrification can solve not only pollution challenges but market challenges, such as ridership and public perception. By addressing the core problems presented by the two-stroke engine and turning challenges into opportunity, a strong attraction is created to convert a two-stroke engine motorcycle to an electric vehicle. With Automotive electric vehicle technology paving the way, the basis for cost effective electric motorcycle powertrain is explored for a 50cc off-road motorcycle application. The 50cc engine and motorcycle represent a special product where size, performance, and cost have a high sensitivity. The 50cc product also represents an area of great opportunity for the product as it is connected to the youth riding segment that establishes the future of motorcycle riding. With both strong opportunity and strong challenges, the electrification solution for a 50cc application provides broad justification for mass market adoption across the motorcycle industry. Challenges will be presented towards a OEM level product where design change is to be minimized without compromising performance. Various challenges include system design, packaging, supply chain, product lifecycle, competition readiness, safety, and cost. Opportunities will be discussed in the context of how the electrified powertrain can create a better product for the rider and solve challenges to enable the next generation of motorcycling. These opportunities include manufacturing advantages, environmental harmony, and new features.
Beeker, Jesse
Development of Hydrogen Powered Fuel Cell e-Snowmobiles2019-32-05551/24/2020
In the highly innovative and holistic flagship project HySnow (Decarbonisation of Winter Tourism by Hydrogen Powered Fuel Cell Snowmobiles), funded by the Austrian Climate and Energy Fund, the decarbonization of winter tourism is being demonstrated. Within this project, two prototype e-snowmobiles have been developed including the adaption of a Polymer Electrolyte Membrane Fuel Cell (PEM-FC) system for the low temperature and high-performance targets and the integration of the drivetrain into the vehicle. In this paper the drivetrain development process of the prototype e-snowmobiles will be presented with the aim to derive specifications for the drivetrain components as PEM-FC system, hydrogen storage system, electric drive, battery and power electronics. Based on typical use cases for snowmobiles overall vehicle specifications and requirements are defined. Associated driving cycles are investigated and used as input for the development process. Subsequently, analyses regarding possible drivetrain topologies based on technical and economical vehicle requirements are carried out. In parallel, vehicle implementation concepts based on standardized development processes are performed. The development and the design process are verified by verification and optimization loops. The results define technical specifications of the PEM-FC, the battery along with the required hydrogen tank; to give an optimum concerning required drivetrain efficiency, and hence driving range as well as vehicle space and weight. It is expected that the hydrogen powered e-snowmobiles with high power, drivability, driving fun, and the lack of noise emission, pollutants, and GHG will convince the users of the concept benefits.
Pertl, Patrick, Aggarwal, Martin, Trattner, Alexander, Hinterberger, Walter, Foxhall, Nigel
Pulsating Heat Pipe Automotive Application2019-36-02271/13/2020
It is proposed a study to evaluate PHP (pulsating heat pipes) device application in battery thermal management systems for HEV (hybrid-electric vehicle) and EV (electric vehicle). Firstly, it is necessary to understanding Li-ion (lithium ion) batteries for HEV/EV, the electrical energy supply state-of-the-art. The analyzed aspects were battery framework and configuration; working principles and mechanisms; and market penetration and potential. Secondly, the adverse effects of temperature over such batteries were discussed. After understanding the case study, a battery modeling survey was performed in order to later evaluate BTMSs (battery thermal management systems). Well comprehended case study and battery modeling, then, it was possible to examine current automotive battery cooling and heating solutions. Finally, PHP was evaluated as a possible BTMS regarding technical and commercial aspects, explaining what would be the requisites in order to attend automobile heat dissipation demands and the challenges for embedding it.
Barbosa de Oliveira, Rafael Beicker, Villalva, Sergio Gradella, Filho, Luiz Paulo Rodrigues, Windlin, Fernando Luiz, Alegre, Guilherme Henrique Mayer, Gonçalves do Santos, Rogério
Balancing Strategy for a Battery Applied in HEV Based on Bi-directional Flyback Converter and Outlier Detection2019-36-02421/13/2020
Dissipative cell balancing generates heat during its operation. Current techniques do not guarantee optimal balance of battery pack energy, requiring a high-cost Battery Management System (BMS) solution and wasting energy in the form of heat. Mild Hybrid Electric Vehicles uses the combustion engine to recharge the battery. Therefore, this feature requires a BMS balancing system capable of optimizing battery capacity and still be energy efficient. In this way, a non-dissipative balancing system would be interesting, especially if an algorithm works with the former non-dissipative balancing method, which efficiently determines which cells are unbalanced. In this paper, a methodology is proposed to perform non-dissipative balance of lithium-ion cells. This method considers which cells inside a certain range are considered balanced and cells outside this range are considered unbalanced. The range is given by the median of the cells terminal voltage summed with a threshold defined by experimental tests. Due the non-dissipative method presented herein is conceived through Flyback topology, the cells above this range are discharged and their extra energy is employed to charge the lowest charged cells, which were below the range. Simulation results which after the first 5 hours of balancing, the maximum difference does not exceed 1% and the standard deviation 0.5% until the end of the simulation, reducing SOC standard deviation by more than 33 times in one day operation. This result shows the strategy is promising to make a more efficient balancing mechanism for Mild Hybrid Electric Vehicles.
Marques, Felipe L. R., Aranha, Juliana C. M. S., Padela, Fernando F., Rosolem, Maria de Fátima N. C., Beck, Raul F.
EV battery-materials testing GETS PHYSICAL20AUTP02_021/1/2020
Reliable materials-testing methodologies are vital for progress in electric-vehicle battery development. A leader in the field explains. A lightweight, higher-capacity lithium-ion or Li-blended battery could speed demand for electric vehicles (EVs) by increasing the driving range, but progress could be easily sidetracked without reliable, repeatable testing methods. “In order to improve the technical capabilities of batteries, mechanical testing must be an integral part of the development process,” said Aleksander Koprivc, automotive industry manager for materials test equipment supplier ZwickRoell. Amid a backdrop of dynamic and static materials testing equipment on display at ZwickRoell's campus in Ulm, Germany, Koprivc and others spoke with Automotive Engineering during the firm's recent 28th International Forum for Materials Testing. The company's customers include 80% of the world's top automotive suppliers, all major global automakers as well as several start-up companies. For those companies involved with eMobility, the quest for better-performing batteries reigns paramount.
Buchholz, Kami
‘Laxatives’ may ease challenge of lithium-ion alternative20AUTP02_101/1/2020
The R&D dimension of the automotive industry often reveals novel solutions and cross-linking between materials, but a team of international scientists has come up with something truly unusual: boosting supercapacitor power and efficiency using newly developed “laxatives.” It's all about developing improved electrolytes as part of a program to enhance supercapacitor performance, making them more practical with enhanced energy storage for use in hybrid and electric vehicles (EVs). To do this, the team designed a new class of detergents involving the use of self-assembled nanostructures in detergent-like ionic liquids (IL), to facilitate improved charge storage at electrified interfaces. These detergents are chemically similar to human laxatives, said Dr. Gavin Hazell, a chemistry lecturer at the University of Chester's Faculty of Science and Engineering, and a member of the international team: “A discovery of this kind utilizes scientists from across the globe. We have a very diverse set of skills including synthetic chemistry, advanced structural, microscopy and computational methods.”
Birch, Stuart
Innovative Fluid Allowing a New and Efficient Battery Thermal Management2019-01-225912/19/2019
With the increasing availability of fast charging stations across the globe, tighter and tighter constraints are placed on electric vehicles batteries. In order to handle the thermal stresses induced during fast charging, the improvement of the existing battery thermal management systems has become key. This article presents an innovative thermal management system for batteries. The system consists of circulating a newly developed highly advanced dielectric fluid in direct contact with the electrochemical cells of the battery pack. Experiments on our dedicated bench test and numerical simulations are reported here demonstrating the performance of this system with fluids, i.e. its ability to efficiently regulate the temperature of the battery cells even under fast charging conditions and low flow rates. Consequently, this thermal management strategy could be implemented within the next generation of battery electric vehicle (BEV) using conventional pumping systems and lead to an improved battery lifetime and therefore a lower total cost of BEV ownership.
RAISIN, Jonathan, CHAMPAGNE, Nicolas
Akasol packs industry-leading energy density into new battery design19TOFHP12_0812/1/2019
Projecting the market for full-electric and hybrid-electric commercial vehicles will continue to expand, Germany-based lithium-ion battery specialist Akasol recently announced production-readiness of a newly-developed battery pack that sets an energy-density benchmark. The company's president also confirmed Akasol will build a manufacturing facility in the Detroit area targeted to begin production in mid-2020. Akasol has a 30-year history of producing battery systems for buses and other commercial vehicles, as well as railway and marine applications. President Roy Schulde says the new American plant is being constructed primarily to build battery packs for buses constructed by European-brand customers doing business in the U.S. The company already claims Europe's largest commercial-vehicle lithium-ion battery production facility.
Visnic, Bill
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