Fang Xuansen, He Yaolong, Fan Xiaomin, Zhang Dan, Hu Hongjiu
Shanghai Institute of Applied Mathematics and Mechanics, School of Mechanics and Engineering Science, Shanghai University, Shanghai 200072, China.
Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai 200072, China.
Polymers (Basel). 2021 Apr 8;13(8):1206. doi: 10.3390/polym13081206.
The prediction of electrochemical performance is the basis for long-term service of all-solid-state-battery (ASSB) regarding the time-aging of solid polymer electrolytes. To get insight into the influence mechanism of electrolyte aging on cell fading, we have established a continuum model for quantitatively analyzing the capacity evolution of the lithium battery during the time-aging process. The simulations have unveiled the phenomenon of electrolyte-aging-induced capacity degradation. The effects of discharge rate, operating temperature, and lithium-salt concentration in the electrolyte, as well as the electrolyte thickness, have also been explored in detail. The results have shown that capacity loss of ASSB is controlled by the decrease in the contact area of the electrolyte/electrode interface at the initial aging stage and is subsequently dominated by the mobilities of lithium-ion across the aging electrolyte. Moreover, reducing the discharge rate or increasing the operating temperature can weaken this cell deterioration. Besides, the thinner electrolyte film with acceptable lithium salt content benefits the durability of the ASSB. It has also been found that the negative effect of the aging electrolytes can be relieved if the electrolyte conductivity is kept being above a critical value under the storage and using conditions.
对于全固态电池（ASSB）而言，考虑到固体聚合物电解质的时间老化情况，预测其电化学性能是实现长期服役的基础。为深入了解电解质老化对电池性能衰退的影响机制，我们建立了一个连续介质模型，用于定量分析锂电池在时间老化过程中的容量演变。模拟揭示了电解质老化导致容量下降的现象。同时，还详细探讨了放电速率、工作温度、电解质中锂盐浓度以及电解质厚度的影响。结果表明，全固态电池的容量损失在老化初期受电解质/电极界面接触面积减小的控制，随后则主要由锂离子在老化电解质中的迁移率决定。此外，降低放电速率或提高工作温度可减轻电池性能的恶化。另外，具有可接受锂盐含量的较薄电解质膜有利于全固态电池的耐久性。研究还发现，如果在储存和使用条件下电解质电导率保持在临界值以上，老化电解质的负面影响可以得到缓解。
