Automobile efficiency improvements using electrochemical capacitor energy storage

MAZDA Motor Corporation has developed an advanced energy recovery system to boost the efficiency in its passenger vehicles. A key feature of this i-ELOOP™ energy recovery system is its use of electrochemical capacitors (EECAP/DLCAP™) that were developed by Nippon Chemi-Con especially for advanced automotive applications. Using this system, fuel consumption typically is reduced 10%. Energy storage technologies other than capacitors were considered for the i-ELOOP™, including lithium-ion batteries, but rejected primarily because they could not provide fast, efficient, and safe charging. This paper describes the storage system architecture then discusses the special capacitors used in this advanced storage system to implement into a conventional passenger vehicle without major design change and the cost impact.