Evaluation of High C Rate Cycle Induced Aging on Low Impedance Lithium-Ion Batteries using In-Situ Electrochemical Impedance Spectroscopy (EIS) Analysis

摘要

The University of Texas at Arlington (UTA) has performed experiments in which high power 3Ah LiNi_xCo_yAl_(1-x-y)O_2 batteries have been studied at high C rates. The first of three identical cells has been discharged using a 10 kHz (50% duty cycle), high C rate (100C/300 A) pulsed discharge procedure and a 1C constant current (CC) - constant voltage (CV) recharge procedure. The second cell has been discharged using a 1C CC procedure and recharged using a 111 mHz (33% duty cycle), high C rate (33C/100 A) pulsed recharge procedure. The third cell, the control cell, has been cycled using a 1C CC discharge procedure and 1C CC-CV recharge procedure. The results of these experiments enable the impact each respective high rate procedure has on cell aging to be better understood. The experimental procedures and methods will be discussed in detail and the results of the experiments will be presented.