LiFePO_4/石墨电池容量衰退与抑制方法

Capacity Fade Mechanisms and the Suppression Methods for LiFePO_4/graphite Cells

从电极材料结构稳定性、铁溶解和锂离子消耗等方面论述了LiFePO4/石墨电池容量衰退的主要机制。在不同条件下造成LiFePO4/石墨电池容量衰退的因素不同,高温以及材料和电解液纯度欠佳时铁溶解比较明显,使用高纯度电池材料常温循环时锂离子消耗是影响电池寿命的关键。在此基础上,探讨了抑制LiFePO4/石墨电池容量衰退的主要方法。

The capacity fade mechanisms for LiFePO4/graphite cells were analyzed in terms of the structural stability of the electrode materials, iron dissolution, and lithium consumption. It indicated different factors responsible for the capacity fade for a LiFePO4/graphite cell cycling under different conditions. Under high temperature or with high impurity for LiFePO4 or electrolyte, there was a severe Fe dissolution. Cycled under room temperature with high purity materials, lithium consumption was the main factor contributing to the capacity decay. Some important approaches to suppress the capacity fade of the LiFePO4/graphite cells were discussed.