Bi-continuous Percolation Phenomena of Lithium Organic/Inorganic Composite Electrolytes

Abstract

Organic/inorganic composite solid electrolytes (CSEs) is anticipated to integrate the merits of inorganic and polymer electrolytes for addressing the challenges in achieving fast ion conduction for post energy storage. But, the unclear Li ion conduction mechanism in the CSEs hinder development of new-CSEs to enhance ionic conductivity. Here, this research has investigated bi-continuous percolation behavior of organic/inorganic phase in the CSEs to understand the Li ion conduction. Percolation of Li6PS5Cl (LPSCl) in the CSEs was formed by regulating elasticity of gel polymer electrolyte (GPE). The CSEs for lower GPE elasticity has higher ionic conductivity of 1.1 x 10-3 S cm-1 at RT than that of higher GPE elasticity. Moreover, this research verified the relation of morphology and lithium ionic conduction behavior by conducting an in-depth analysis of ionic conductivity, morphology and isotopeexchange 7Li NMR measurement. Through model study, this research also found that the GPE elasticity played a key role in the bi-continuous percolation formation. This study provides insights for bicontinuous percolation in CSEs to develop rationally designed electrolytes with high-ionic conductivity and safety for all-solid-state rechargeable lithium metal batteries.