Browse Topic: Ultracapacitors and supercapacitors

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A Multi-Objective Power Component Optimal Sizing Model for Battery Electric Vehicles2021-01-072404/06/2021
With recent advances in electric vehicles, there is a plethora of powertrain topologies and components available in the market. Thus, the performance of electric vehicles is highly sensitive to the choice of various powertrain components. This paper presents a multi-objective optimization model that can optimally select component sizes for batteries, supercapacitors, and motors in regular passenger battery-electric vehicles (BEVs). The BEV topology presented here is a hybrid BEV which consists of both a battery pack and a supercapacitor bank. Focus is placed on optimal selection of the battery pack, motor, and supercapacitor combination, from a set of commercially available options, that minimizes the capital cost of the selected power components, the fuel cost over the vehicle lifespan, and the 0-60 mph acceleration time. Available batteries, supercapacitors, and motors are from a market survey. The considered lifespan is taken as 10 years, and the traveling distance is estimated at
Shinde, Akash, Kshirsagar, Kunal, Arshad, Saad Bin, Patil, Unmesh, Zhang, Jiangfeng
Stretchable Micro-Supercapacitors to Self-Power Wearable DevicesTBMG-3854802/01/2021
A stretchable system that can harvest energy from human breathing and motion for use in wearable health-monitoring devices may be possible, according to an international team of researchers, led by Huanyu “Larry” Cheng, the Dorothy Quiggle Career Development Professor in Penn State’s department of engineering science and mechanics. The research team, with members from Penn State and Minjiang University and Nanjing University, both in China, recently published its results in Nano Energy.
Supercapacitor Based on Manganese OxideTBMG-3833801/01/2021
A new supercapacitor based on manganese oxide could combine the storage capacity of batteries with the high power and fast charging of other supercapacitors. By combining manganese oxide with cobalt manganese oxide, a heterostructure is formed in which interfacial properties can be tuned.
Design of a Flexible Hybrid Powertrain Using a 48 V-Battery and a Supercapacitor for Ultra-Light Urban Vehicles2020-01-044504/14/2020
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
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 Roads2019-01-212909/15/2019
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
Feng, Jia'ao, Tian, Zhongpeng, Cui, Jian, Zhou, Fangyu, Tan, Gangfeng
Stretchable Power Source for WearablesTBMG-3473707/01/2019
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.
Impedance Modeling and Aging Research of the Lithium-Ion Batteries Using the EIS Technique2019-01-059604/02/2019
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
Gao, Qian, Dai, Haifeng, Wei, Xuezhe, Jiang, Bo
Fabric Alternative to Batteries for Wearable DevicesTBMG-3414804/01/2019
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 nanotubes2018-36-031309/03/2018
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
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 capacitors2018-36-031009/03/2018
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
Real, Carla Giselle Martins, Vicentini, Rafael, Nunes, Willian Gonçalves, Boas, Otávio Vilas, Alves, Thayane Almeida, Soares, Davi Marcelo, Zanin, Hudson
Inexpensive Method for Manufacturing Supercapacitor ElectrodesTBMG-2830902/01/2018
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-2815601/01/2018
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 Battery2017-01-119803/28/2017
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
Hong, Po, Jiang, Hongliang, Li, Jian qiu, Xu, Liangfei, Ouyang, Minggao
Energy Harvesting in Automotive Key fob Application2017-26-035101/10/2017
Evolution in Radio Frequency (RF) semiconductor technology has led to highly power efficient devices. A typical automobile key fob for remote lock-unlock operations operates on 3V lithium coin cell battery having 200 mAh capacity and can last up to 75,000 key press events or two to three years. The typical transmission currents are less than 10 mA while sleep currents are less than 0.1 uA. As the lithium coin cell batteries are not rechargeable, they need to be replaced and safely disposed. Improper disposal of lithium batteries impose risk to the environment as lithium is highly poisonous and reactive. This paper proposes to replace the coin cell battery with a RF energy harvesting circuit involving voltage multiplier circuit consisting of zero bias schottky detector diodes and a hybrid energy storage capacitor. Authors have conducted experiments as well as simulation to evaluate the feasibility of the RF energy harvester replacing conventional coin cell battery. RF energy harvesting
Gambhir, Ameya, Yadav, Dhananjay, Pawar, Ganesh
Nanowire Yarn Boosts Supercapacitor EfficiencyTBMG-2250107/09/2015
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-2163303/01/2015
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 Perspective2014-01-184604/01/2014
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
Arasaratnam, Ienkaran, Tjong, Jimi, Habibi, Saeid
Ultra-Capacitor based Hybrid Energy Storage and Energy Management for Mild Hybrid Vehicles2014-01-188204/01/2014
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
Kulkarni, Swanand S., Gandhi, Nikita, Chaithanya, Naga, Govindarajan, Srinivasan
Li-Ion Battery and Supercapacitor Hybrid Design for Long Extravehicular ActivitiesTBMG-1718209/01/2013
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 Principles2013-01-064504/08/2013
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
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 Transients2013-01-153504/08/2013
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
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
Brewer, Roger
Electrochemical Ultracapacitors Using Graphitic NanostacksTBMG-1357105/01/2012
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.
Remotely Powered Reconfigurable Receiver for Extreme Environment Sensing PlatformsTBMG-1325404/01/2012
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 (
Substituted Quaternary Ammonium Salts Improve Low-Temperature Performance of Double-Layer CapacitorsTBMG-TB-01188410/24/2011
Low cell resistances are observed when used with modified acetonitrile electrolyte blends. Double-layer capacitors are unique energy storage devices, capable of supporting large current pulses as well as a very high number of charging and discharging cycles. The performance of double-layer capacitors is highly dependent on the nature of the electrolyte system used. Many applications, including for electric and fuel cell vehicles, back-up diesel generators, wind generator pitch control back-up power systems, environmental and structural distributed sensors, and spacecraft avionics, can potentially benefit from the use of double-layer capacitors with lower equivalent series resistances (ESRs) over wider temperature limits. Higher ESRs result in decreased power output, which is a particular problem at lower temperatures. Commercially available cells are typically rated for operation down to only –40 °C.
Optimal Market Niches for High-Power Ultracapacitors in Automotive and Mass-Transit ApplicationsTP-AAB-AABC_EUROPE_2011_3506/11/2011
Presentation by Yunasko on "Optimal Market Niches for High-Power Ultracapacitors in Automotive and Mass-Transit Applications" for AABC Europe 2011.
Maletin, Yurii
Hybrid Ultracapacitors and Potential Automotive ApplicationsTP-AAB-AABC_EUROPE_2011_3006/11/2011
Presentation of Ioxus background; Ioxus Technology; Hybrid capacitor products and summary.
Hall, Chad
Energy Storage in High P:E ApplicationsTP-AAB-AABC_EUROPE_2011_3106/11/2011
Presentation by Corning regarding value comparison between ultracapacitor and Li-Ion systems.
Bell, Phillip
Advanced Carbons for Electrochemical CapacitorsTP-AAB-AABC_EUROPE_2011_2006/11/2011
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
Batteries and Ultracapacitors - A Perfect MatchTP-AAB-AABC_EUROPE_2011_3406/11/2011
Presentation by Maxwell Technologies regarding batteries and ultracapacitors for AABC Europe 2011.
Cowperthwaite, Jeremy
Ultracapacitor-Based Uninterrupted Power Supply SystemTBMG-1013306/01/2011
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 Device2010-01-176511/02/2010
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
James, John E., Tsenter, Boris
New Concept of SupercapacitorTP-AAB-US_2010_1905/21/2010
Presentation of "New Concept of Supercapacitor" by Poznan University of Technology for AABC US 2010.
Frackowiak, Elzbieta, Lota, Grzegorz, Fic, Krzysztof
The Ultracapacitor IndustryTP-AAB-AABC_US_2010_2905/21/2010
Ioxus' perspective of the ultracapacitor Industry for AABC US 2010.
Jaworski, Robert K.
Ultracapacitors as the Key to Efficient Power SolutionsTP-AAB-AABC_US_2010_3205/21/2010
Presentation of "Ultracapacitors as the Key to Efficient Power Solutions" by Yunasko for AABC US 2010.
Maletin, Yurii
What is Good Carbon Performance in an Ultracapacitor?TP-AAB-AABC_US_2010_2505/21/2010
Presentation of "What is Good Carbon Performance in an Ultracapacitor?" for AABC US 2010.
Feaver, Aaron
Application of Ultracapacitors for HEV Transit BusesTP-AAB-AABC_US_2010_3305/21/2010
Presentation by BAE Systems of "Application of Ultracapacitors for HEV Transit Buses" for AABC US 2010.
Hess, Robert
The Development of Nesscap 125V UC Module for Transportation ApplicationsTP-AAB-AABC_US_2010_3505/21/2010
Presentation includes: Basic prinicples of EDLCs and modules; NESSCAP 125V ultracapacitor module; and example applications.
Park, Jin
Ultracapacitors as the Key to Efficient Power SolutionsTP-AAB-US_2010_P_1905/21/2010
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
Tailored Carbon Black for Applications in SupercapacitorsTP-AAB-AABC_US_2010_2205/21/2010
Presentation by Cabot of "Tailored Carbon Black for Applications in Supercapacitors" for AABC US 2010.
Kossyrev, Pavel
Supercapacitor Electrolyte Solvents With Liquid Range Below –80 °CTBMG-656901/01/2010
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.
Fuel-Cell-Powered Vehicle With Hybrid Power ManagementTBMG-667801/01/2010
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-TB-00656912/23/2009
New formulations extend operation into lower temperatures. 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.
Advanced Automotive Ultracapacitor Technology to Reduce CO2 EmissionsTP-AAB-AABC_2009_5306/10/2009
Presentation of "Advanced Automotive Ultracapacitor Technology to Reduce CO2 Emissions" for Advanced Automotive Battery Conference.
Tertrais, Frederic
Experiences of the Hybrid Energy Storage System Sitras HES based on a NiMH-battery and Double Layer Capacitors in Tram OperationTP-AAB-AABC_2009_3606/10/2009
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
Striking capacitance of carbon/iodide interfaceTP-AAB-AABC_2009_2006/10/2009
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
Frackowiak, Elzbieta, Lota, Grzegorz
In-situ monitoring of EDLCs operation by physico-chemical techniquesTP-AAB-AABC_2009_2106/10/2009
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
Kötz, Rüdiger, Ruch, Patrick W., Cericola, Dario
Hybrid Ultracapacitor Using A 3-Dimensional Nanofilm CathodeTP-AAB-AABC_2009_P_3806/10/2009
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
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_3706/10/2009
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_3606/10/2009
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
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