Finite Element Analysis of LATP Solid Electrolyte under Compressive Loading

Abstract

Solid state battery (SSB) is potentially favorably as energy storage for electric vehicles because of the higher energy density offered and the use of solid electrolytes with good thermal resistance that solve the safety problems induced by fluid electrolytes. However, cracks that appear during charge-discharge cycling on the SSB have not been cleared up by this recent development and ended up affecting the battery performance. This crack arises from high compressive loading cycles by the volume change of the anode and cathode during lithiation/delithiation, in which the crack propagation can affect the conductivity of solid electrolyte ions. Therefore, this study aims to determine and analyze the effect of compressive loading on the cracking of solid electrolytes toward ionic conductivity. The research was carried out by giving a compressive load of 0.15 MPa to $\mathrm{L}\mathrm{i}_{1.3}\mathrm{A}1_{0.3}\mathrm{T}\mathrm{i}_{1.7}(\mathrm{P}\mathrm{O}_{4})_{3}$ (LATP) solid electrolyte. A Cohesive Zone Element is applied to the grain boundaries of LATP solid electrolyte to simulate the cracking process. The result was analyzed and showed that ionic conductivity increases under compressive loading but was expected to decrease when the crack appears.