金属氢化物镍蓄电池SOC估计的EIS研究

Study on electrochemical impedance spectroscope for determining the state-of-charge of nickel metal hydride battery

研究了6.5Ah圆柱形金属氢化物镍(MH-Ni)蓄电池不同荷电状态(SOC)下的电化学交流阻抗谱(EIS),结果表明EIS等效电路的欧姆内阻Rs以及电荷转移内阻Rt随着电池SOC增加变化较小,难以用于电池SOC估计;而电池常相位角元件(CPE)参量及特征频率f*与电池SOC之间存在良好的单调依赖关系,可作为MH-Ni电池SOC有效估计的参数。

Electrochemical impedance spectroscopes （EISs） of a 6,5 Ah cylindrical sealed nickel metal hydride （Ni-MH） battery were studied at different state-of-charges （SOCs）. The EIS results show that the ohmic resistance R s and the charge-transfer resistance R ,of the equivalent circuit change with the increasing of the SOC, can hardly be used for determining SOC of the Ni-MH battery. While the parameters of constant-phase element （CPE） and the eigenfrequency f＊ of the EISs show good monotonous dependency on SOC respectively, are helpful to determine the SOC of Ni-MH battery.