MH-Ni蓄电池在不同放电深度下的阻抗行为

通过电化学阻抗谱分别研究了正极、负极在不同放电深度下的阻抗。结果表明,随着放电深度增大,正极的欧姆内阻增加,发生电极反应的活性表面积减小,电化学反应电阻和质子扩散阻抗增大。负极电化学反应电阻先减小后增大,放电平台段电化学反应电阻变化很小,MH-Ni蓄电池放电初期的电化学极化主要来源于负极。

Electrochemical impedance behavior of Ni-MH battery under different depth of discharge

EIS(Electrochemical Impedance Spectroscopy) test of positive electrode and negative electrode under different depth of discharge showed that ohmic resistance, electrochemical reaction resistance and diffuse resistance of positive electrode increased with deeper discharge, while the active area where the reaction took place decreased. Electrochemical reaction resistance of negative electrode decreased firstly and then increased, which changed indistinctly during the discharge platform. When the discharge was not very deep, the electrochemical reaction resistance of Ni-MH battery was mainly due to negative electrode.