Recent Developments and Challenges in Hybrid Solid Electrolytes for Lithium-Ion Batteries

Lu Han,Tianyi Liu,Xiaomin Tang,Zhengping Zhou,Tomonori Saito,Jiadeng Zhu,Pengfei Cao,Chien-Te Heish,Xi Chelsea Chen,Alexei P Sokolov,Michelle L Lehmann

doi:10.3389/fenrg.2020.00202

Abstract

Lithium-ion batteries (LIBs) have attracted worldwide research interest due to their high energy density and long cycle life. Solid-state LIBs improve the safety of conventional liquid-based LIBs by replacing the flammable organic electrolytes with a solid electrolyte. Among the various types of solid electrolytes, hybrid solid electrolytes (HSEs) demonstrate great promise to achieve high ionic conductivity, reduced interfacial resistance between the electrolyte and electrodes, mechanical robustness, and excellent processability due to the combined advantages of both polymer and inorganic electrolyte. This article summarizes recent developments in HSEs for LIBs. Approaches for the preparation of hybrid electrolytes and current understanding of ion-transport mechanisms are discussed. The main challenges including unsatisfactory ionic conductivity and perspectives of HSEs for LIBs are highlighted for future development. The present review provides insights into HSE development to allow a more efficient and target-oriented future endeavor on achieving high-performance solid-state LIBs.

Highlights

The results showed that the solid electrolyte made from PCs with (CH2)x exhibited an optimal conductivity and lowest Tg when x = 7
In poly(ethylene oxide) (PEO)-based electrolyte systems, studies have shown that the crystallization of the polymer is suppressed with the addition of inert fillers, which further increases the ionic conductivity (Bouchet et al, 2013; Hanson et al, 2013; Khurana et al, 2014; Das and Ghosh, 2015; Zhu et al, 2018a)
Researchers have shown that the addition of γ-LiAlO2 filler into PEO-based electrolyte greatly reduces the crystallization rate, increasing ionic conductivity, and the lithium/electrolyte interfacial stability (Hu et al, 2007; Tan et al, 2016)

Summary

Introduction

Lithium-ion batteries (LIBs) have revolutionized battery technologies, serving as the key component in personal portable electronics, electric vehicles, and stationary energy storage (Ge et al, 2014; Yanilmaz et al, 2016; Zhu et al, 2016b,d; Luo et al, 2017; Famprikis et al, 2019; Lagadec et al, 2019; Lee et al, 2019; Liu et al, 2019; Zhao et al, 2020). With the incorporation of lithium salts, the ionic conductivity of solid-state polymer electrolytes can reach 10−6 to 10−5 S/cm at room temperature (Wang et al, 2016; Meabe et al, 2019). The same strategy was applied to PEO-based composite, resulting in an increased ionic conductivity of 2.4 × 10−4 S/cm at room temperature (Zhu et al, 2018a).

Results

Conclusion