Comparison of supercapacitor and lithium-ion capacitor technologies for power electronics applications

Abstract

New developments in double-layer capacitor technology are yielding devices with ever more wide ranging characteristics. Particularly interesting is the trend of increasing maximum cell voltage whilst maintaining the high capacitance which characterises these devices. The desire to improve the existing technology has led to the development of an asymmetric lithium-ion capacitor technology with impressive energy storage characteristics. Presented is a direct comparison between this new technology and a more traditional supercapacitor technology relevant for power electronic applications. A new hierarchy of comparisons is introduced which is used to define, compare and contrast techniques regarding these devices for power electronic interface. Results from experimentation on real-world components are presented and conclusions drawn from the response to input conditions designed to characterise the devices. A technique for derivation of an equivalent circuit is presented for each device. (5 pages)