A method of characterizing high energy density capacitors for power conditioning systems

An effort was made to develop methods for characterizing CDL (chemical double layer) capacitors in terms of percent energy transfer to a resistive load as well as energy density packaging capabilities. A novel soft charging method, in contrast to constant-voltage charging, was developed to increase the energy density by approximately 1600% of the CDL capacitors´ rated value. This method consists of slowly increasing the terminal voltage to approximately four times its rated value, achieving energy densities on the order of 4.5 kJ/kg (with case) and 6.5 kJ/kg (without case) for a life of several days. The capacitor studied showed promise in DC storage applications where high energy densities are required for relatively long discharge times