Rechargeable Battery Expo 2014: Regenerative energy storage devices

New uses for capacitors and nickel metal-hydride battery systems



Two-seater electric vehicle "Miluira" powered by lithium-ion capacitors (exhibited by Asahi Kasei FDK Energy Device)

 The 5th International Rechargeable Battery Expo was held at Tokyo Big Sight on February 26 to 28, 2014. This report highlights the exhibitions of storage devices for start-stop systems and brake energy regeneration systems.
 Demand for start-stop systems is increasing rapidly as a cost-effective fuel-saving technology. However, load of the system is too large for ordinary lead-acid batteries and special batteries have been developed exclusively for use with start-stop systems. Concurrently, storage devices that assist lead-acid batteries have been increasingly used. These storage devices include electric double layer capacitors, lithium-ion batteries and nickel metal-hydride batteries.
 The exhibitors also displayed capacitors used as storage devices in electric and hybrid vehicles. Electric double layer capacitors by Ioxus and lithium-ion capacitors by JM Energy are used in hybrid buses in markets outside Japan.

 This report also introduces an energy regeneration system with nickel metal-hydride batteries, developed by Panasonic, as an example of new storage devices (The product was not exhibited at the Expo). The batteries are supplied to Nissan and Mitsubishi Motors for their start-stop systems.

Storage devices for start-stop and energy regeneration systems

Storage devices Usage case in Japan Suppliers Description
Special lead-acid batteries Many Lead-acid battery
Special lead-acid batteries are developed with enhanced input characteristics and cycle life.

New devices
Electric double
layer capacitor
Mazda & Honda
Nippon Chemi-con New devices assist lead-acid batteries, enhance charging and discharging capacities, and extend their service life.
Lithium-ion battery Suzuki
(Enecharge system)
Nickel metal-hydride
Nissan & Mitsubishi

Related reports: The International Rechargeable Battery Expo 2013 (posted in March 2013)