Influence of over-discharge on the lifetime and performance of LiFePO₄/graphite batteries

Abstract

In this study, the degradation of a LiFePO4/graphite battery under an over-discharge process and its effect on further cycling stability are investigated.

Impedance Characterization of an LCO-NMC/Graphite Cell: Ohmic Conduction, SEI Transport and Charge-Transfer Phenomenon

“…Serial resistance represents the ohmic losses related to the electronic conduction-including electrode particles, tabs, and current collectors-and the ionic conduction through the electrolyte [65]. RC networks represent interfaces that form inside the cells.…”

Effects of Overdischarge Rate on Thermal Runaway of NCM811 Li-Ion Batteries

“…When the battery was overdischarged to 0 V, its thickness increased by 70%, and the direct current resistance increased by 250%. Zheng et al [12] reported that when a battery was overdischarged to a low voltage, the solid electrolyte interphase (SEI) membrane dissolved and cracked; consequently, H 2 , CH 4 , and C 2 H 6 gases are generated in batteries whose overdischarge cut-off voltage is 1 V. Juarez et al [13] discovered that the maximum surface temperature of a battery during overdischarge was highly dependent on the C-rate. The surface temperature of a battery overdischarged at 1 C reached 79 • C. Ouyang [14] reported that the temperature rise of batteries increased during overcharging/overdischarging.…”

Investigation of a commercial lithium-ion battery under overcharge/over-discharge failure conditions

“…So far, considerable studies have been done to examine the inuence of overcharge/over-discharge on LIBs including electrochemical performances and aging characteristics. [6][7][8][9][10][11][12][13][14][15] Yuan et al 6 investigated the safety behaviors of a 32 A h prismatic LIB under abusive charge conditions by monitoring the internal and external cell temperature variations, and the results showed that the internal resistance of the overcharged battery became 5-7 times than that of the 100% SOC battery. Xu et al 7 systematically studied the failure mechanism of LiFePO 4 LIBs during overcharge conditions from 5-20% overcharge.…”

“…They found that the impedance of the anode was much smaller than that of the cathode, but it dominated the impedance increase when the cell was overdischarged, which indicated that the SEI (solid electrolyte interface) change on the anode surface was much larger than that on the cathode. Besides, to investigate the degradation of an LiFePO 4 /graphite battery under an over-discharge process and its effect on further cycling stability, Zheng et al 12 conducted a set of experiments. Their results revealed that batteries over-discharged to 0.5-0.0 V experienced serious irreversible capacity losses of 12.56-24.88%, i.e., a serious loss of active lithium and anode materials occurred during the over-discharge process.…”