ECCAP Symposium: Large EC Capacitor Technology and Application. AABC Europe 2012 - Session 2

In this session we review new capacitor products and EC business development. Leaders from key companies will discuss future products and business strategies as they expand their product offerings to support growth of energy-efficient industrial, utility, and transportation-related energy storage systems.

Session Chairman:
John R. Miller, President, JME, Inc.

Dr. Miller is President of JME, Inc., a consulting firm specializing in ultracapacitor development, testing, and application. John is a well-known expert in ultracapacitor technology with 25 years of experience in the industry. In the past five years, prior to joining the AABC team, he has chaired the Advanced Capacitor World Summit.

1. The Technology Just Keeps Going…
   Michael Liedtke, VP Business Development, Market Intelligence and Strategic Planning, Maxwell Technologies
   Abstract 

   

   This presentation looks at current challenges and future opportunities for Ultracapacitors within the Automotive realm but also beyond.

   Points to be discussed:

   • Update on Maxwell
     • New facility
     • Volume updates
     • Updates on Maxwell Technologies since the last AABC in Mainz.
      
   • Maturing of market
     • Cell Level
     • Module Level
     • What has happened on a cell level and also module level. Developments on a global perspective.
      
   • Ultracapacitors in Japan
   • Japanese Applications
   • Acetonitrile myths
     • The truth and nothing but the truth
      
   • Shipping of Ultracapacitors products
     • Update on activities related to shipping Ultracapacitors based on Kilofarad initiatives
      
   • Maxwell Application specific Product Offerings
     • Engine Start Module (ESM) and its variants
     • UPS Module
      
   • Automotive Outlook
   • Conclusion

   Close Abstract
2. Nano-Hybrid Capacitor and Its Materials
   Kenji Tamamitsu, Chief of Research Center, Nippon Chemi-Con Corporation
   Abstract 

   

   Nippon Chemi-con Corporation has developed Nano-hybrid capacitor using a nano-sized Li₄Ti₅O₁₂/carbon nanofiber (CNF) composite as a negative electrode material.

   Characteristic of the Nano-hybrid capacitor is as follows:

   • Energy density of ca. 30 Wh L^-1, which is almost three times as higher than conventional EDLC
   • Power density comparable with conventional EDLC
   • High safety due to no Li dendrite
   • High performance at low temperature which is ca. 80 % of capacitance retention at -30 ^oC

   The Characteristics meet demands for automotive applications such as relatively high energy density, high safety, and rapid charging/discharging at low temperatures.
   Some of the high performances are attributed to the unique structure of the Li₄Ti₅O₁₂/CNF composite prepared by our nano-hybrid technique. The Li₄Ti₅O₁₂ particles in the composite have diameters ranging from ca. 5 to 20 nm and are grafted onto the outer and inner surfaces of the CNFs.
   This nano-structure can overcome inherent problems of poor Li⁺ diffusivity and low electric conductivity in Li₄Ti₅O₁₂ material. Moreover, electrochemical reaction at low temperature can be also facilitated due to the reduced activation energy in electrochemical reaction by nano-sizing of Li₄Ti₅O₁₂.
   Furthermore, we have prepared Li₄Ti₅O₁₂ based composite using single walled carbon nanotube (SWCNT) instead of CNF. The Li₄Ti₅O₁₂/SWCNT composite showed even higher rate capability than the Li4Ti5O12/CNF composite. This remarkably high rate capability is attributed to further down-sizing of Li₄Ti₅O₁₂ that enhance Li⁺ diffusivity and mesopore network of the SWCNT that allows an entanglement effect of the Li₄Ti₅O₁₂ and SWCNT.
   Our nano-hybrid technique which uniformly complex nano-sized Li₄Ti₅O₁₂ and nanocarbon make it possible to create various metallic oxide based composites. Therefore, it enables to apply many other electrochemical energy storage devices. We will also focus on development of lithium ion battery (LIB) materials such as SnO₂, LiFePO₄ and so on. The LIB materials prepared by our nano-hybrid technique can be expected to offer additional value such as high rate capability and cycle ability as well as Li₄Ti₅O₁₂/nanocarbon composite.

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3. YUNASKO Ultracapacitors: 3 Ways to Cut Cost
   Yurii Maletin, Chief Scientist, YUNASKO Ltd.
   Abstract 

   

   The idea of this presentation is to demonstrate three ways of ultracapacitor cost reduction, since the high cost is one of the main obstacles for market adoption. A list of presentation content includes:

   • Company background
   • YUNASKO breakthrough story and competitive advantage
   • Way #1 to reduce cost: high performance
   • Way #2 to reduce cost: low cost electrodes
   • Way #3 to reduce cost: wide scaling and geography

   A key approach that YUNASKO has been pursuing over the past years is the role of ultracapacitor performance in competition with other energy storage technologies. Since the carbon/carbon ultracapacitors obviously fail the energy density (typically below 5 W.h/kg), their low internal resistance resulting in high power density and high efficiency becomes their major advantage. Today YUNASKO ultracapacitors demonstrate much lower resistance than any other competitor devices, and this implies them to meet customer requirements with less volume and mass (and hence, lower cost!).

   Since the low energy density can still be an issue for many applications, YUNASKO has also developed hybrid devices comprising the electrode and electrolyte components from both ultracapacitor and Li-ion technologies. The YUNASKO hybrids demonstrate outstanding performance with their energy density of ca.35W.h/kg while keeping at the same time the power density beating most of carbon/carbon devices available on the market.

   Some other ways to reduce the ultracapacitor cost, namely, the use of low cost electrode materials and close-to-customer location of industrial scale production of ultracapacitors are also among the YUNASKO priorities.

   Close Abstract
4. Use of EDLCs in Start-Stop Systems
   Anthony Kongats, Chief Executive Officer/Managing Director, Cap-XX
   Abstract 

   

   Electrification of vehicles is gaining momentum to reduce fuel consumption and emissions. Electrification covers a spectrum from Stop-Start technology, mild hybrid with some energy capture from regenerative braking, HEV through to EV's. Stop-Start systems in particular, are gaining acceptance with vehicle manufacturers in Europe, Asia and the USA. In vehicles fitted with a Stop-Start system, the engine management system turns off the engine whenever the car is stopped in traffic, saving fuel and reducing emissions. When the driver decides to move on, e.g. by depressing the clutch or accelerator, the engine restarts. The result is a dramatic increase in the number of engine starts required in a typical day, from a handful in a standard car, to as many as 100s starts in a car with Stop-Start technology. Without some mitigating changes to the vehicle's power systems, this will result in an early death for the lead acid battery. One strategy is to use a supercapacitor to do the engine cranking. This paper will show a power architecture for a supercapacitor enabled Stop-Start system, with results comparing its performance and endurance against that of a battery alone. Our tests show that using the supercapacitor in this manner significantly extends battery run time. In this system the battery is only needed to supply hotel loads (radio, air-conditioning etc.) for extended periods when the engine is not running, with the supercapacitor cranking the engine without any contribution from the battery.

   Close Abstract
5. Aqueous Electrolyte Hybrid-Ion Electrochemical Cells For Scaled Energy Storage
   Jay Whitacre, Founder & CTO, Aquion Energy
   Abstract 

   

   This presentation will cover the scaling implementation of large-scale energy storage electrochemical batteries. Data will be presented showing that large scale industrially packaged individual batteries with over 30 Wh in capacity have be produced and qualified. Further data will show that packs of these batteries in the kWh range have been effectively implemented in field-testing. This will include support for both smaller off-grid applications with bus voltages in the in the 20 to 100 V range, as well as, grid compatible systems with bus voltages in excess of 1000 V. Key topics to be addressed include: (1) a description of our path to scaled production of these devices, (2) lifetime performance of this system in temperatures ranging from minus 10˚C through 60˚C, (3) data from third party field tests in relevant applications showing the performance of our batteries under application specific load profiles, and (3) our vision for future implementation of this technology on a massive scale.

   • Project Targets for the Aquion battery:
     • In-house pilot manufacturing, scaling to full manufacturing in 2013
     • First large scale aqueous electrolyte asymmetric hybrid energy storage device
     • Qualification and validation of a high voltage string battery concept
     • Further understanding of customer behavior.
      
   • The Aquion Energy battery concept:
     • Large format polypropolyene casing with > 100 Wh per unit, 4 to 8 V potential swing
     • High voltage strings (over 1000 V) demonstrated with no cell level BMS
     • Highly modular for sizes 1 kWh through >>MWh installations
      
   • Summary:
     • Low cost aqueous electorlyte battery scaled and field tested
     • Simple to use at systems level, completely safe and non-toxic
     • Very appealing for stationary applications.
      

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6. Performance of Novel Phosphonium Ionic Liquids as Electrolytes in Electrical Double Layer Capacitors
   Werner Kuhr, Strategic Technical Counsel, eSionic Corp
   Abstract 

   

   eSionic Corp. has developed a novel set of ionic liquids with improved thermal stability, conductivity, viscosity and chemical stability. Our materials are designed to utilize inexpensive chemistries, and offer important improvements in many important chemical properties including viscosity, heat capacity, melting point, boiling point and thermal conductivity. Many candidate molecules (>200) were synthesized, purified and characterized. Room temperature ionic liquids were identified and further evaluated. Selected molecules were evaluated for their performance with regard to thermal stability, conductivity and electrochemical stability. Unique advantages include low vapor pressures, low viscosity over a wide temperature range, extremely soluble in propylene carbonate and other non-aqueous solvents, high conductivity compared to non-aqueous solvents and chemistry that is scalable for production.

   Electrolyte properties using ionic liquids and acetonitrile show good conductivity, a large voltage window and good performance in a 100 F EDLC. eSionic EDLC capacitors showed a superior lifetime than conventional electrolytes, and exhibited a rated lifetime roughly 2x better than controls. Results suggest that EDLCs made with eSionic ionic liquid electrolyte might provide substantially longer life products, which would be significant in that energy storage systems are designed with specified end-of-life operation as a goal. Two-fold or greater life increase may be possible, which would be significant in many of today’s popular large applications and truly represent an advancement with high-value. An attractive feature here is this represents a “drop-in” solution with a minimum barrier for acceptance.

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7. High Performance Activated Carbons for Ion Storage
   Stephen Lipka, Adjunct Professor, Department of Electrical and Computer Engineering, University of Kentucky
   Abstract 

   

   This presentation will discuss the synthesis and electrochemical performance of activated carbons prepared from a low-cost hydrothermal process using various carbohydrate solutions. Carbons synthesized by the hydrothermal process are spherical in nature and can be grown in a range of diameters, (typically 40 nm – 8 μm) with a high degree of monodispersity. The resulting uniformity of diameters results in a high packing density when the materials are formed into electrode structures. A brief overview of the hydrothermal process is given, along with the effect process variables has on material properties. Electrochemical performance of activated spherical carbons prepared from the hydrothermal process in both aqueous and nonaqueous electrolytes will be presented. Performance data for selected asymmetric systems using these activated carbons will also be discussed.Time permitting, opportunities for these materials in other electrochemical storage devices will be presented.

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