锂硫电池模拟与仿真

A Mathematical Model for a Lithium-Sulfur Cell

多硫化物沉淀反应造成电极活性比表面积大量减少,是锂硫电池放电性能降低的主要原因。采用形核-生长沉淀模型描述锂硫电池沉淀过程。同时,采用误差函数erf(x)修正锂硫电池活性比表面积减少对电池放电阶段性能的影响。在实验数据与计算结果相吻合的前提条件下,进一步计算结果表明:多硫化物Li2S2和Li2S较高的生长速率可以提高放电电压平台,而增加S2-的形核和生长速率均有利于提高锂硫电池的放电容量。

The active surface loss due to the precipitation of polysulfides causes lithium-sulfur cell capacity fade.A mathematical model of nucleation and growth of polysulfides is presented to describe the effect of polysulfides＆#39; precipitation in the lithium-sulfur cell.In addition,error function of eft（x） is used to modify capacity fade of lithium-sulfur cell due to active surface loss.The model is validated using experimental discharge curves obtained from literature with fairly high accuracy.Furthermore,the necessity of rapid precipitation of lower polysulfides is discussed in detail.Increasing growth rates of Li2S2 and Li2S cause the potential plateau raised.And increasing growth and nucleation rate of S2-is necessary to enhance discharge capacity.