基于交流阻抗谱的锂离子电池老化模式量化方法

Quantification of degradation mode using electrochemical impedance spectroscopy of lithium-ion battery

针对锂离子电池老化实验过程中交流阻抗谱呈现2种不同变化趋势的现象,加入了双等效电路模型分析的思路,设计了一种能适用于2种交流阻抗谱特性的老化模式量化方法.根据这种老化模式量化方法,进行不同条件的电池老化实验,并研究了3种老化模式的变化趋势,指出一个适用于本实验电池的多种老化条件下的统一规律:活性锂离子损失和活性材料损失在老化过程中影响比较明显,其中活性材料损失影响最为明显,与活性材料损失相比,电导率损失与活性锂离子损失在老化过程中的影响较弱.

The electrochemical impedance spectroscopy of lithium-ion battery shows two different trends during the aging experiment. The idea of using two equivalent circuit models is add in the article. And the quantization method for degradation mode which can be applied to the two trends of electrochemical impedance spectrum is designed. According to the method, the battery aging experiments are performed under different conditions and the trends of three degradation modes are analyzed. And the phenomenon suitable for the battery used in the article is pointed out. The loss of lithium inventory and the loss of active material prove to be important in battery aging process, and the loss of active material proves to be more important. However, the conductivity loss has a little effect compared with the loss of lithium inventory and the loss of active material.