过充电对MH—Ni电池电化学性能的影响

The Effects of Overcharge on Electrochemical Performance of MH-Ni Batteries

检测并比较了不同过充电电流对AA型MH—Ni电池电化学性能的影响,实验结果表明,电池按国标以0.4C充至标称容量后,继续以0.4C过充,电池内压继续呈缓慢上升,其升高速度在电池容量达到2000mAh之前基本不变;当以1C过充时,电池内压上升速度明显加快;当以0.1C过充时,电池内压的升高速度下降,在电池容量达到1600mAh之后,其速度变化趋于平稳。不同电流的过充电,对电池循环衰退速度和电池放电电压下降速度的影响与电池内压升高速度的变化成正比。

The effects of different overcharge currents on electrochemical performance of AA size sealedtype nickel/metal hydride batteries have been investigated in this paper. The results indicate that after charging with 0.4C to its original capacity and go on overcharging with 0. 4C, the inner pressure of MH-Ni battery increases slowly and its increasing velocity remaines constant on the whole before the capacity reache 2000mAh; When overcharging with 1C, the increasing velocity of inner pressure quicken obviously; When with 0.1C, the increasing velocity of inner pressure slackened and remaine constant after the capacity reache 1600mAh. The relationship between the effects of different overcharge currents on the increasing velocity of inner pressure and the degradation velocity of cycle life and discharge voltage remains direct proportion.