Modeling and Simulation in Capacity Degradation and Control of All-Solid-State Lithium Battery Based on Time-Aging Polymer Electrolyte.

Xuansen Fang,Yaolong He,Hongjiu Hu,Xiaomin Fan,Dan Zhang

doi:10.3390/polym13081206

Abstract

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.

Highlights

Solid polymer electrolytes (SPEs) are emerging as a promising solution to achieve broad electrochemical stability window, excellent mechanical properties, and good safety for developing high-performance all-solid-state batteries (ASSB) [1,2,3,4]
Accounting for the SPE time-aging during the storage condition, a full-field coupling
Accounting for the SPE time-aging during the storage condition, a full-field coupling model of thermodynamics-electrochemistry-mechanics has been established for the ASSB

Summary

Introduction

Solid polymer electrolytes (SPEs) are emerging as a promising solution to achieve broad electrochemical stability window, excellent mechanical properties, and good safety for developing high-performance all-solid-state batteries (ASSB) [1,2,3,4]. The time-aging may occur in the amorphous polymer and can significantly affect the migration of lithium-ion in the solid electrolyte [7,8]. It would change the distribution of lithium concentration in the active material and lead to cell capacity variation. The evolution of ionic conduction of SPEs and relevance to electrochemical behavior of ASSB during the aging process of polymer electrolyte are crucial scientific problems to be solved. As one of the most critical parameters of SPE, the time-dependent conductivity of polymer electrolyte materials has already attracted much attention. As early as 2003, Kumar et al noticed that storage time had greatly affected the ionic conductivity of poly(ethylene oxide) (PEO) based

Methods

Discussion

Conclusion