The Impact of High Pulsed Loading on the Fatigue of Electrochemical Energy Storage Devices

UT Arlington is researching the impact high pulsed loading has on high power electrochemical energy storage devices. Fundamental effects on aging due to high pulsed loading are being investigated by studying the capacity fade and changes in the cells electrochemical impedance [1]. Experiments have been performed in which a 3Ah LiNixCoyAl1-x-yO2cell is discharged at rates as high as 83C (250 A) in a 10 kHz pulsed fashion for 140s. A 1C recharge procedure is used between discharge cycles. The experimental results obtained when cycling at elevated rates are compared to results obtained from a second identical cell which is charged using a 1C constant current (CC) - constant voltage (CV) procedure and discharged at a constant 1C rate. This paper describes the experiments performed and shows the impact high pulsed loading has on the aging and capacity fade of a high power lithium-ion battery after fifty cycles have been performed.