Browse Topic: Ultracapacitors and supercapacitors

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Design of a Flexible Hybrid Powertrain Using a 48 V-Battery and a Supercapacitor for Ultra-Light Urban Vehicles2020-01-04454/14/2020
Global warming has put the transport sector, a major contributor of CO2 emissions, under high pressure to improve efficiency. In this context, ultra-light vehicles weighting less than 500 kg, as well as hybrid powertrains, are nowadays seen as promising development trends. The design process of the powertrain of a vehicle combining the advantages of the two concepts is presented in this paper. Through a performance study based on a simple MATLAB model, and mathematical simulation, a proposal is made. A powertrain using a battery and supercapacitor 48V dual power source network, two electric motors and clutches to switch between conventional, parallel, series and full electric modes proves to be an interesting system in terms of performance and costs. A simulation study conducted on a scenario with different outcome possibilities showed that high modularity of the system allows to achieve fuel efficiencies equivalent to approximately 3 l/100 km on the Artemis cycle. Finally, integration, packaging and cost are considered and some hints for further powertrain efficiency improvements are presented.
El Ganaoui-Mourlan, Ouafae, Miliani, El Hadj, Carlos Da Silva, Daniel, Couillandeau, Matthieu, Gonod, Charlie, Miller, Guillaume
Downhill Safety Assistant Driving System for Battery Electric Vehicles on Mountain Roads2019-01-21299/15/2019
When driving in mountainous areas, vehicles often encounter downhill conditions. To ensure safe driving, it is necessary to control the speed of vehicles. For internal combustion engine vehicles, auxiliary brake such as engine brake can be used to alleviate the thermal load caused by the continuous braking of the friction brake. For battery electric vehicles (BEVs), regenerative braking can be used as auxiliary braking to improve brake safety. And through regenerative braking, energy can be partly converted into electrical energy and stored in accumulators (such as power batteries and supercapacitors), thus extending the mileage. However, the driver's line of sight in the mountains is limited, resulting in a certain degree of blindness in driving, so it is impossible to fully guarantee the safety and energy saving of downhill driving. Therefore, taking a pure electric light truck as an example, the system proposed in this paper first analyzes the driver's driving intention, proposes the system startup and exit strategy, and then combines the geographic information system (GIS) mountain road information, downslope speed limit and vehicle parameters, considering the motor and battery characteristics, establishes mathematical models such as the regenerative braking model and the brake temperature rise model based on vehicle dynamics and the conservation of energy, determines the appropriate braking mode(There are two braking modes)and the slope top safe speed by calculation, and reminds the driver when going uphill and downhill. The main goal is to use more regenerative braking, reduce the use or duration of the main brake, avoid overheating the main brake, improve the safety during continuous braking, and achieve smarter energy management. Finally, simulations are carried out under different conditions of vehicle speed, slope length, slope gradient and battery SOC. The results show that the system has a good energy-saving effect and can significantly improve the safety of BEVs running downhill.
Feng, Jia'ao, Tian, Zhongpeng, Cui, Jian, Zhou, Fangyu, Tan, Gangfeng
Stretchable Power Source for WearablesTBMG-347377/1/2019
Researchers have created highly stretchable supercapacitors for powering wearable electronics that consist of crumpled carbon nanotube (CNT) forests. The supercapacitors demonstrated solid performance and stability, even when stretched to 800% of their original size for thousands of stretching/relaxing cycles.
Self-Powered Wearable TechTBMG-345606/1/2019
Researchers have created highly stretchable supercapacitors for powering wearable electronics. The newly developed supercapacitor has demonstrated solid performance and stability, even when it is stretched to 800 percent of its original size for thousands of stretching/relaxing cycles.
Stretchable Interlaced-Nanowire Film for Ultraviolet Photodetectors with High Response SpeedTBMG-345886/1/2019
Stretchable electronics, which can be stretched, deformed and wrapped onto nonplanar curved surfaces, have attracted much attraction due to their potential applications in wearable electronics, implantable biomedical devices, and artificial electronic skin. So far, many types of stretchable electronic devices have been developed including stretchable transistors, light-emitting diodes (LEDs), supercapacitors, photodetectors and sensors. Ultraviolet (UV) photodetectors have wide applications in crime investigation, biological analysis, fire monitoring, UV irradiation detection and many other applications as well.
Impedance Modeling and Aging Research of the Lithium-Ion Batteries Using the EIS Technique2019-01-05964/2/2019
As the core component of electric vehicles (EVs), batteries attach increasingly general attention along with the rapid expansion of electric vehicle market. Battery performance effect directly the safety and reliability of the EVs, so its managing technologies are more and more crucial. Among them, the methods of estimating the state of health (SoH) and predicting remaining useful life become the focuses, which are essential to ensure their dependability and optimum performance over time. This paper mainly focuses on impedance modeling and aging research (aging diagnosis and life prediction) of lithium-ion batteries. Electrochemical impedance spectroscopy (EIS) technique is used to obtain impedance characteristic of batteries. On the one hand, equivalent circuit modeling (ECM) can be motivated by EIS, with the goal to fit measured impedance data using circuit elements. On the other hand, the aging research of batteries can be analyzed using the resistance information provided by EIS due to the correlation between battery resistance and lifetime. The possible causes of battery aging are analyzed based on changes in the impedance spectrum, which are obtained under different life conditions through an accelerated life experiment. According to the result and the corresponding electrode process, an improved Randels model is then established. Furthermore, a method to predict the battery life based on EIS is proposed. The battery life characterization parameters and calculation methods are defined according to related test manuals and standards. Then, the impedance amplitude of a certain frequency is selected as an estimation parameter. Finally, the first-order polynomial is selected as the fitting function comparing with the fitting results of various functions.
Gao, Qian, Dai, Haifeng, Wei, Xuezhe, Jiang, Bo
Fabric Alternative to Batteries for Wearable DevicesTBMG-341484/1/2019
Wearable biosensors for health monitoring lack a lightweight, long-lasting power supply. A new method was developed for making a charge-storing system that is easily integrated into clothing for embroidering a charge-storing pattern onto any garment.
Electric double layer capacitors prepared with polyvinyl alcohol and multi-walled carbon nanotubes2018-36-03139/3/2018
Portable electronics, wearables, electric vehicles and solar cells are sectors in increasingly development which include innovation and miniaturization of the devices. In this scenario, the development of smaller and lightweight energy storage devices, which store more energy, is required. Besides, it is desirable for these devices to be environmentally friendly to minimize pollution. In an attempt to meet these requirements, this work purposes the development and the characterization of nanofibers-based electrode composed of Polyvinyl alcohol (PVA) and multi-walled carbon nanotubes (MWCNT) for electric double layer capacitors (ELCDs) devices with aqueous electrolyte. This composite has been prepared by electrospinning technique and consolidate an electrical conductive and high-surface material electrode. After that, the PVA/MWCNT electrode was assembled in coin cell device with Sodium Sulfate (Na2SO4) electrolyte for electrochemical characterization. The characterization results showed that EDLCs devices present specific capacitance of ∼4.8 Fg-1, energy density of ∼0.1 Wh kg-1, power density of ∼600W kg-, fast charge transfer at electrode/electrolyte interface and high lifetime All these results encourage further development on PVA/MWCNT materials as electrode for EDLCs and Li-Air batteries devices. This new generation of devices are opening niches of applications on multi billionaire markets from communication to transport.
Real, Carla Giselle Martins, Vicentini, Rafael, Nunes, Willian Gonçalves, Boas, Otávio Vilas, Costa, Lenon Henrique, Soares, Davi Marcelo, Zanin, Hudson
Polyacrylonitrile and activated carbon composite for electric double layer capacitors2018-36-03109/3/2018
Electrospinning of polymers blends solutions offers the potential to produce nanofibers for using in a variety of applications. Here, we report the synthesis of nanofibers with polyacrylonitrile (PAN) and activated carbon (AC) composite by employing this technique. As-produced material is an electrical conductive and high-surface material electrode with outstanding electrochemical properties, which we explore electric double layer capacitors (EDLCs) coin cell devices. Our results show that EDLCs manufactured with PAN/AC composite have fairly high specific capacitance, low internal impedance and high lifetime. All these results encourage further development of PAN/AC materials as electrode for EDLCs and Li- Air batteries devices. This new generation of devices are opening niches of applications on multi-millionaire markets such as electric vehicles & solar and wind power systems. Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The authors solely responsible for the content of the paper.
Real, Carla Giselle Martins, Vicentini, Rafael, Nunes, Willian Gonçalves, Boas, Otávio Vilas, Alves, Thayane Almeida, Soares, Davi Marcelo, Zanin, Hudson
Controlled Manufacture of Porous Silicon CarbideTBMG-328619/1/2018
Extremely fine porous structures with tiny holes — resembling a kind of sponge at the nano level — can be generated in semiconductors. A method was developed for the controlled manufacture of porous silicon carbide (SiC), which has significant advantages over silicon. It possesses greater chemical resistance and can be used for biological applications, for example, without any additional coating required.
Novel, Solid-State Hybrid Ultracapacitor BatteryTBMG-283232/1/2018
NASA's Marshall Space Flight Center has developed a solid-state ultracapacitor with a unique combination of high capacitance and battery-like discharge characteristics. The high capacitance in a solid-state form can enable a new type of ultracapacitor, and in combination with the ability to deliver sustained power like a battery, can perhaps enable an entirely new class of energy storage devices.
Inexpensive Method for Manufacturing Supercapacitor ElectrodesTBMG-283092/1/2018
Supercapacitors can store and deliver energy faster than conventional batteries. But to realize advanced applications, supercapacitors need better electrodes, which connect the supercapacitor to the devices that depend on their energy. These electrodes need to be both quicker and cheaper to make on a large scale, and also able to charge and discharge their electrical load faster.
Process Turns Carbon Dioxide into 3D Graphene with Microporous SurfaceTBMG-281561/1/2018
The conversion of carbon dioxide to useful materials usually requires high energy input due to its ultrahigh stability. A heat-releasing reaction between carbon dioxide and sodium was developed to take carbon dioxide and turn it into 3D graphene with micropores across its surface.
Modeling and Experiment Validation of the DC/DC Converter for Online AC Impedance Identification of the Lithium-Ion Battery2017-01-11983/28/2017
The lithium-ion battery plays an important role in saving energy and lowering emissions. Many parameters like temperature have an influence on the characteristic of the battery and this phenomenon becomes more serious in an electric vehicle. In this paper, the application of a boost DC/DC converter to the battery system of high power for online AC impedance identification is proposed. The function of the converter is to inject a current excitation signal into the battery at work and the normal output current is drawn by a load. Through analyzing the average state space equations and deriving the small signal model of the converter, the gain function is deduced of the fluctuated current signal against the fluctuated duty cycle which controls the converter. The control algorithm is designed and the system model is verified using Matlab/Simulink with respect to the disturbance current signal generation, the gain function and its variation with frequency range. Then the converter is designed and implemented to conduct the experiment on a power battery of 175Ah and the nominal voltage is 100V. The measured AC impedance of several single cells is presented and it demonstrates the feasibility of applying this DC/DC converter to the practical electric vehicle.
Hong, Po, Jiang, Hongliang, Li, Jian qiu, Xu, Liangfei, Ouyang, Minggao
Nanowire Yarn Boosts Supercapacitor EfficiencyTBMG-225017/9/2015
Researchers at the Massachusetts Institute of Technology discovered that yarn made of niobium nanowires enables more efficient supercapacitors. The new approach uses the yarns as the electrodes in tiny supercapacitors. Adding a coating of a conductive polymer to the yarn further increases the capacitor’s charge capacity.
Carbon Nanotube Tower-Based SupercapacitorTBMG-216333/1/2015
A new technology to create electrochemical double-layer supercapacitors is provided using carbon nanotubes as electrodes of the storage medium. This invention allows efficient transport between the capacitor electrodes through the porous nature of the nanotubes, and has a low interface resistance between the electrode material and the collector. Carbon nanotubes directly grown on a metal surface are used to improve the supercapacitor performance. The nanotubes offer a high surface area and usable porosity for a given volume and mass, both of which are highly desirable for supercapacitor operation.
Switched-Capacitor Cell Balancing: A Fresh Perspective2014-01-18464/1/2014
No two battery cells can be identical. Charging/discharging a battery pack without monitoring cell voltages or SoC (State-of-Charge) will cause cell voltages to deviate over time and the packs useable capacity to decrease quickly. To redistribute charge uniformly among cells, various cell balancing methods have been proposed in the literature. In this paper, a cell balancing method based on a single switched-capacitor is presented from a brand new perspective. Unlike the traditional balancing methods that rely on the voltage divergence criterion, this paper uses the SoC divergence criterion to shuttle charge from a highly charged cell to a poorly charged cell. Moreover, an equivalent resistance of the single-switched capacitor topology is derived in steady state. For fast cell balancing, design guidelines are provided for selecting a proper switching-time period and the capacitor parameters. Ultracapacitors are recommended to achieve this goal. To demonstrate the effectiveness of the proposed method, numerous simulations are performed on a string of five series connected Lithium-ion cells that have different initial SoCs and electrochemical parameters. Finally, the simulation results are compared with that of a traditional balancing method.
Arasaratnam, Ienkaran, Tjong, Jimi, Habibi, Saeid
Ultra-Capacitor based Hybrid Energy Storage and Energy Management for Mild Hybrid Vehicles2014-01-18824/1/2014
In a Mild hybrid electric vehicle, a battery serves as a continuous source of energy but is inefficient in supplying peak power demands required during torque assists for short duration. Moreover, the random charging and discharging that result due to varying drive cycle of the vehicle affects the life of the battery. In this paper, an Ultra-capacitor based hybrid energy storage system (HESS) has been developed for mild hybrid vehicle which aims at utilizing the advantages of ultracapacitors by combining them with lead-acid batteries, to improve the overall performance of the battery, and to increase their useful life. Active current-sharing is achieved by interfacing ultracapacitor to the battery through a bi-directional boost dc-dc converter. Furthermore, an energy management system (EMS) is developed that controls the power flow between the two sources and the load and determines the amount of charging of ultracapacitor either from the battery or during regeneration depending on the predictions based on the drive-cycle and the remaining energy of the ultracapacitor. The system is developed and implemented on a test-bench in combination with Lead-acid batteries and the performance is evaluated for step change in load. It is observed that the system has quick dynamic response. The DC-DC converter is realized using a MOSFET based converter and the control strategy is implemented using TMS320F28335 DSP.
Kulkarni, Swanand S., Gandhi, Nikita, Chaithanya, Naga, Govindarajan, Srinivasan
Li-Ion Battery and Supercapacitor Hybrid Design for Long Extravehicular ActivitiesTBMG-171829/1/2013
With the need for long periods of extravehicular activities (EVAs) on the Moon or Mars or a near-asteroid, the need for long-performance batteries has increased significantly. The energy requirements for the EVA suit, as well as surface systems such as rovers, have increased significantly due to the number of applications they need to power at the same time. However, even with the best state-of-the-art Li-ion batteries, it is not possible to power the suit or the rovers for the extended period of performance. Carrying a charging system along with the batteries makes it cumbersome and requires a self-contained power source for the charging system that is usually not possible. An innovative method to charge and use the Li-ion batteries for long periods seems to be necessary and hence, with the advent of the Li-ion supercapacitors, a method has been developed to extend the performance period of the Li-ion power system for future exploration applications.
Use of Finite Element Simulation for Modeling Vertically Aligned Carbon Nanotube Arrays Based on Structural Mechanics Principles2013-01-06454/8/2013
Carbon nanomaterials such as vertically aligned carbon nanotubes arrays are emerging new materials that have demonstrated superior mechanical, thermal, and electrical properties. The carbon nanomaterials have the huge potential for a wide range of vehicular applications, including lightweight and multifunctional composites, high-efficiency batteries and ultracapacitors, durable thermal coatings, etc. In order to design the carbon nanomaterials for various applications, it is very important to develop effective computational methods to model such materials and structures. The present work presents a structural mechanics approach to effectively model the mechanical behavior of vertically aligned carbon nanotube arrays. The carbon nanotube may be viewed as a geometrical space frame structure with primary bonds between any two neighboring atoms and thus can be modeled using three-dimensional beam elements. Effects of tube geometric factors (wall thickness and tube diameter) and material properties (Poisson's ratio) on mechanical properties of the nanotube structure were examined. Results show that the Young's modulus is inversely proportional to the nanotube wall thickness and Poisson's ratio. On the other hand, the Young's modulus and shear modulus exhibit nonlinear relationships with the nanotube diameter, i.e., both moduli increase rapidly at smaller diameters but become stabilized at larger diameters. Compression test conducted on VACNT array shows linear behavior for the values of applied strains in the present case.
Joseph, Johnson, Lu, Y Charles
Pulse Power Testing of Batteries and Supercapacitors for Hybrid Electric Vehicle Applications: A Comparison of Constant Current, Constant Power, and Ramped Power Transients2013-01-15354/8/2013
The central performance requirement for electrochemical energy storage systems for the full power-assist hybrid electric vehicle (HEV) is pulse power capability, typically 25-40 kW pulse power capability for 10 seconds duration. Standard test procedures utilize constant current pulses. However, in the HEV application, the power transient for acceleration is a ramped power transient and the power transient for regenerative braking power is a descending power ramp. This paper compares the usable power capability of batteries and supercapacitors under constant current, constant power, and ramped power transients. Although the usable battery discharge power is relatively insensitive to the transient type applied, 10-40% higher regenerative braking charge capability is observed with ramped power transients. With supercapacitors, the discharge and charge capability is much more strongly dependent on the type of power transient. The discharge power capability in a ramped power transient is 2.4 times that in a constant current pulse. The regen charge power capability is over 3 times that in a constant current pulse. Standard constant current test procedures thus underestimate the power capability of supercapacitors for HEV applications by several-fold. Supercapacitors provided over 2500 W/kg usable power for HEV applications, exceeding that of high power nickel metal hydride and lithium ion batteries tested.
Corrigan, Dennis A., Liu, Xiao
Electrical Energy Storage to Meet Evolving Aircraft Needs2012-01-219910/22/2012
The value of “ultracapacitors” (also referred to as “supercapacitors” or “electric double layer capacitors” in some literature) as an augmentation device when placed in parallel with “electrochemical” energy storage (i.e. battery) is presented in this paper. Since ultracapacitors possess unique attributes due to their higher value of energy storage density (or Joules/WattHrs per mass) compared to conventional capacitors while maintaining the peak power providing capability (to some degree) typical of conventional capacitors they may provide a near term solution in applications demanding longer battery operating life when placed in parallel. Such demands may be pronounced by the onset of More-Electric-Aircraft peak loads and “cold-crank” Auxiliary Power Unit (APU) electric-starting in demanding cold temperature environments. The potential benefits of an ultracapacitor in parallel with a battery will be illustrated through a very simple lab demonstration as well as a more complex system consisting of a large motor inrush load (cold-cranking condition) through the use of a computer simulation tool (Simulink). In addition to the ultracapacitor discussions and demonstration, other forms of advanced energy storage will be reviewed for their potential near or long term application in meeting the evolving needs of More Electric Aircraft as presented at the 2011 International Double Layer Capacitor and Hybrid Energy Storage Seminar in Deerfield Beach Florida (Reference 3).
Brewer, Roger
Electrochemical Ultracapacitors Using Graphitic NanostacksTBMG-135715/1/2012
Electrochemical ultracapacitors (ECs) have been developed using graphitic nanostacks as the electrode material. The advantages of this technology will be the reduction of device size due to superior power densities and relative powers compared to traditional activated carbon electrodes. External testing showed that these materials display reduced discharge response times compared to state-of-the-art materials. Such applications are advantageous for pulsed power applications such as burst communications (satellites, cell phones), electromechanical actuators, and battery load leveling in electric vehicles. These carbon nanostructures are highly conductive and offer an ordered mesopore network. These attributes will provide more complete electrolyte wetting, and faster release of stored charge compared to activated carbon.
Integrated Energy Storage Systems to Optimize Payback Period of Hybrid Vehicles2012-01-03414/16/2012
Enhancements of today's Micro-Hybrids based on stop-start systems with and without coasting and energy recuperation show a positive cost-benefit and a much shorter payback period compared to more complex and expensive Full-Hybrid concepts. However, improved Micro-Hybrid functionalities have a higher demand on the vehicle's electrical power network, which cannot be covered with traditional topologies alone. To enable the advanced Micro-Hybrid features, additional energy storage elements like second lead acid batteries, double-layer capacitors or lithium-ion cell based storage systems will be integrated into the power network. This will stabilize the network and provide a reliable source of energy. To apply even further reaching measures like creeping (also called crawling), and high power recuperation, a dual voltage power network will be required. This can be achieved by adding a second voltage level to the traditional 12V power network. In order to connect power networks with different voltage levels, DC/DC converters are required. This paper will discuss the constraints of a cost-optimum topology for each power class of DC/DC converter from Micro- up to Mild-Hybrid applications and present solutions to overcome these limitations. Furthermore, the different topologies are compared in regards of their economic benefit using the total cost of ownership model.
Rosenmayr, Marc, Brown, Alan, Schmidt, Rainer
Remotely Powered Reconfigurable Receiver for Extreme Environment Sensing PlatformsTBMG-132544/1/2012
Wireless sensors connected in a local network offer revolutionary exploration capabilities, but the current solutions do not work in extreme environments of low temperatures (200K) and low to moderate radiation levels (
Batteries and Ultracapacitors - A Perfect MatchTP-AAB-AABC_EUROPE_2011_346/11/2011
Presentation by Maxwell Technologies regarding batteries and ultracapacitors for AABC Europe 2011.
Cowperthwaite, Jeremy
Hybrid Ultracapacitors and Potential Automotive ApplicationsTP-AAB-AABC_EUROPE_2011_306/11/2011
Presentation of Ioxus background; Ioxus Technology; Hybrid capacitor products and summary.
Hall, Chad
Energy Storage in High P:E ApplicationsTP-AAB-AABC_EUROPE_2011_316/11/2011
Presentation by Corning regarding value comparison between ultracapacitor and Li-Ion systems.
Bell, Phillip
Advanced Carbons for Electrochemical CapacitorsTP-AAB-AABC_EUROPE_2011_206/11/2011
There are many families of carbon materials that can be used as active electrode materials, conductive additives and even current collectors. Supercapacitor performance can be enhanced by creating designed architectures, tailoring porosity and using exohedral nanostructures that are matched synergistically with appropriate electrolyte systems. By moving from trial-and-error tests to science-driven design of nanostructured carbon electrodes we can develop new materials and architectures to dramatically boost energy and power densities of electrochemical capacitors.
Gogotsi, Yury
Optimal Market Niches for High-Power Ultracapacitors in Automotive and Mass-Transit ApplicationsTP-AAB-AABC_EUROPE_2011_356/11/2011
Presentation by Yunasko on "Optimal Market Niches for High-Power Ultracapacitors in Automotive and Mass-Transit Applications" for AABC Europe 2011.
Maletin, Yurii
Ultracapacitor-Based Uninterrupted Power Supply SystemTBMG-101336/1/2011
The ultracapacitor-based uninterrupted power supply (UPS) system enhances system reliability; reduces life-of-system, maintenance, and downtime costs; and greatly reduces environmental impact when compared to conventional UPS energy storage systems. This design provides power when required and absorbs power when required to smooth the system load and also has excellent low-temperature performance. The UPS used during hardware tests at Glenn is an efficient, compact, maintenance-free, rack-mount, pure sine-wave inverter unit.The UPS provides a continuous output power up to 1,700 W with a surge rating of 1,870 W for up to one minute at a nominal output voltage of 115 VAC. The ultracapacitor energy storage system tested in conjunction with the UPS is rated at 5.8 F. This is a bank of ten symmetric ultracapacitor modules.
SOH Recognition of Li-ion Aviation Batteries Via Passive Diagnostic Device2010-01-176511/2/2010
Aviation battery maintenance is trending toward on-condition maintenance. Nickel-Cadmium (NiCd), Valve Regulated Lead-Acid (VRLA), or Lithium-Ion (Li-ion) batteries are used to start engines, provide emergency back-up power, and assure ground power capability for maintenance and pre-flight checkout. As these functions are mission essential, recognition of battery state of health (SOH) is critical. SOH includes information regarding battery energy, power and residual cycle life along with monitoring overall battery safety. This paper describes an SOH recognition technique for on-board Li-Ion aviation batteries and discusses a passive diagnostic device (PDD), that analyzes input data derived from normal system parameters such as battery current, voltage and ambient temperature. These parameters are monitored in a totally passive mode eliminating the need for active signals to the battery. Active signals are restricted or even prohibited in order to avoid any interference with the vehicle electrical system. A procedure for sampling and analyzing transient and stationary battery voltage and current and establishing a matrix of battery parameters (MoP) is discussed. The basis for SOH recognition is based on a matrix of parameters containing values for ohm and chemical resistance, instantaneous and dynamic open circuit voltage, and Tafel coefficients of electrode reactions. Because Li-ion battery charging is provided under precise controlled conditions, data are sampled and processed both in charging and discharging modes. Advantages discussed are the capability of the PDD to provide early signs of impending battery failure or simply the inability of the battery to carry out a necessary function, or the need for off-line battery maintenance.
James, John E., Tsenter, Boris
New Concept of SupercapacitorTP-AAB-US_2010_195/21/2010
Presentation of "New Concept of Supercapacitor" by Poznan University of Technology for AABC US 2010.
Frackowiak, Elzbieta, Lota, Grzegorz, Fic, Krzysztof
What is Good Carbon Performance in an Ultracapacitor?TP-AAB-AABC_US_2010_255/21/2010
Presentation of "What is Good Carbon Performance in an Ultracapacitor?" for AABC US 2010.
Feaver, Aaron
Ultracapacitors as the Key to Efficient Power SolutionsTP-AAB-US_2010_P_195/21/2010
The last decade has shown that ultracapacitors face some difficulties to carve their way to the automotive market. In our opinion, the main reason for certain skepticism from automakers side is a pretty fast progress in Li-ion technology on the one hand, and rather slow progress in ultracapacitor technology, on the other hand. To become really competitive in the automotive market, ultracapacitors must demonstrate by far higher power density (and, accordingly, much lower inner resistance) than Li-ion or any other batteries. This, accompanied by ultracapacitors long life, wide operation temperature range and safety, will help them to clear their way to the market.
Maletin, Yurii
Ultracapacitors as the Key to Efficient Power SolutionsTP-AAB-AABC_US_2010_325/21/2010
Presentation of "Ultracapacitors as the Key to Efficient Power Solutions" by Yunasko for AABC US 2010.
Maletin, Yurii
The Development of Nesscap 125V UC Module for Transportation ApplicationsTP-AAB-AABC_US_2010_355/21/2010
Presentation includes: Basic prinicples of EDLCs and modules; NESSCAP 125V ultracapacitor module; and example applications.
Park, Jin
Application of Ultracapacitors for HEV Transit BusesTP-AAB-AABC_US_2010_335/21/2010
Presentation by BAE Systems of "Application of Ultracapacitors for HEV Transit Buses" for AABC US 2010.
Hess, Robert
Tailored Carbon Black for Applications in SupercapacitorsTP-AAB-AABC_US_2010_225/21/2010
Presentation by Cabot of "Tailored Carbon Black for Applications in Supercapacitors" for AABC US 2010.
Kossyrev, Pavel
The Ultracapacitor IndustryTP-AAB-AABC_US_2010_295/21/2010
Ioxus' perspective of the ultracapacitor Industry for AABC US 2010.
Jaworski, Robert K.
Fuel-Cell-Powered Vehicle With Hybrid Power ManagementTBMG-66781/1/2010
NASA Glenn Research Center has developed a hybrid electric utility vehicle that is powered by hydrogen-burning PEM fuel cells operating with a metal hydride hydrogen-storage unit. This vehicle utilizes ultracapacitors - rather than batteries - for storing electric energy.
Supercapacitor Electrolyte Solvents With Liquid Range Below –80 °CTBMG-65691/1/2010
A previous NASA Tech Brief [“Low-Temperature Supercapacitors” (NPO-44386) NASA Tech Briefs, Vol. 32, No 7 (July 2008), page 32] detailed ongoing efforts to develop non-aqueous supercapacitor electrolytes capable of supporting operation at temperatures below commercially available cells (which are typically limited to charging and discharging at ≥40 °C). These electrolyte systems may enable energy storage and power delivery for systems operating in extreme environments, such as those encountered in the Polar regions on Earth or in the exploration of space. Supercapacitors using these electrolytes may also offer improved power delivery performance at moderately low temperatures (e.g., –40 to 0 °C) relative to currently available cells, offering improved cold-cranking and cold-weather acceleration capabilities for electrical or hybrid vehicles.
In-situ monitoring of EDLCs operation by physico-chemical techniquesTP-AAB-AABC_2009_216/10/2009
A fundamental understanding of the processes occurring during electrochemical double layer capacitor (EDLC) operation is a prerequisite for estimating the performance limits of these devices and for the suggestion of measures for improvement. Most of today’s commercially available EDLCs are based on activated carbon (AC) electrodes and utilize an organic electrolyte. These devices typically show specific energies around 5 Wh/kg, which for some applications is not sufficient. In order to increase the energy of an EDLC there are two options; (i) increase the capacitance of activated carbons by utilizing so called advanced carbons or (ii) increase the nominal voltage of the capacitor by driving the electrodes to higher/lower potentials. While the former approach would only promote the energy of the device, the latter will also increase the power. In this presentation the two approaches will be discussed, explicitly limited to so-called double layer capacitors excluding pseudo capacitance and redox materials like oxides or polymers.
Kötz, Rüdiger, Ruch, Patrick W., Cericola, Dario
Hybrid Ultracapacitor Using A 3-Dimensional Nanofilm CathodeTP-AAB-AABC_2009_P_386/10/2009
The current generation of electrochemical capacitors or “ultracapacitors” are primarily electric double layer capacitor “EDLC” devices. They utilize symmetric electrodes of activated carbon in an organic electrolyte. Recent efforts to increase ultracapacitor energy density have focused on a hybrid architecture utilizing asymmetric electrodes: one being activated carbon, the other a faradaic “battery-like” material. Such a device will provide a value proposition superior to EDLC and lithium ion batteries in terms of cost (monetary, mass or volume)/energy stored/charge cycle. To obtain optimal capacitor-like performance from the battery-like materials, Ionova has developed a novel 3-dimensional nanoscopic film (“3-D Nanofilm™”) electrode technology. While the hybrid ultracapacitor architecture in general and 3-D Nanofilm™ electrode technology in particular may be used with organic or aqueous electrolytes, this paper discusses the characteristics of a 3-D Nanofilm™ hybrid ultracapacitor in an aqueous electrolyte.
Seymour, Fraser
Study of Fast Ion Transport of Ionic Liquids in Self-Assembly Layer-by-Layer Electrodes for Ionic Polymer Actuators and UltracapacitorsTP-AAB-AABC_2009_P_376/10/2009
Penn State University and Virginia Tech presentation of "Study of Fast Ion Transport of Ionic Liquids in Self-Assembly Layer-by-Layer Electrodes for Ionic Polymer Actuators and Ultracapacitors" at Advanced Automotive Battery Conference.
Liu, Sheng, Lin, Minren, Liu, Yang, Montazami, Reza, Jain, Vaibhav, Heflin, James R., Zhang, Qiming
Gas Analysis of Ultracapacitor: Electric Double Layer Capacitor using Acetonitrile Based ElectrolyteTP-AAB-AABC_2009_P_366/10/2009
High power, high energy and long term reliability feature of Ultracapacitor enables this component to use in various applications as backup power unit, auxiliary power unit and renewable energy storage system. Until now, to satisfy market needs such as higher power, more energy, environment friendly and safety requirements, we have investigated various sorts of electrode materials, electrolyte and other components in the whole system. During this investigation, we focused on gas generation phenomenon which is caused by acetonitrile based electrolyte in electric double layer capacitor especially in abuse condition and is believed as the main reason of environmental and safety problem because of its toxic gaseous substance such as HCN.
Kim, Jun-Ho, Kang, Jin-A, Lee, Ha-Young, Her, Chul, Kim, Heui-Soo, Lee, Hee-Younng
Advanced Automotive Ultracapacitor Technology to Reduce CO2 EmissionsTP-AAB-AABC_2009_536/10/2009
Presentation of "Advanced Automotive Ultracapacitor Technology to Reduce CO2 Emissions" for Advanced Automotive Battery Conference.
Tertrais, Frederic
Striking capacitance of carbon/iodide interfaceTP-AAB-AABC_2009_206/10/2009
Exceptional electrochemical behaviour of carbon/iodide interface has been demonstrated and successfully used in supercapacitor application. This efficient charge storage is based on specific sorption of iodide ions as well as stable reversible redox reactions connected with various possible oxidation states of iodine from –1 to +5. An intriguing effect of iodide ions has been observed for positive electrode operating in a narrow range of potential and giving extremely high capacitance values exceeding 1840 F/g. KI plays a useful dual role, i.e. electrolytic solution with a good ionic conductivity as well as a source of pseudo-capacitive effects. As opposed to typical pseudocapacitance effects, which are often characterized by some diffusion limitations and observed only at moderate regimes, our innovative two-electrode system can be loaded until 50 A/g supplying still 125 F/g. Amazing capacitance of carbon/iodide interface has also been confirmed during long-term cycling (over 10 000 cycles).
Frackowiak, Elzbieta, Lota, Grzegorz
Experiences of the Hybrid Energy Storage System Sitras HES based on a NiMH-battery and Double Layer Capacitors in Tram OperationTP-AAB-AABC_2009_366/10/2009
Siemens presentation of "Experiences of the Hybrid Energy Storage System Sitras HES based on a NiMH-battery and Double Layer Capacitors in Tram Operation" at Advanced Automotive Battery Conference
Meinert, Michael
Fuel Economy and Performance of Mild Hybrids with UltracapacitorsTP-AAB-2009_376/9/2009
Simulations and Vehicle Test Results presentation for the AABC 2009.
Gonder, Jeff, Pesaran, Ahmad, Lustbader, Jason, Tataria, Harshad
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