Solid hybrid electrolytes based on conductive oxides and polymer electrolytes for all-solid-lithium batteries

Abstract

All-solid-state lithium batteries (ASSLBs) have attracted significant attention owing to their high energy density and enhanced safety compared to lithium-ion batteries. Among the various solid electrolytes, solid hybrid electrolytes (SHEs) combine the advantages of organic and inorganic electrolytes. These SHEs exhibit improved ionic conductivity, ease of processing, and flexibility, making them promising candidates for high-performance ASSLBs. However, several challenges and unresolved issues remain in the successful development of ASSLBs. One key challenge is to achieve high ionic conductivity at room temperature, as it directly affects the cycling performance of the ASSLBs. Additionally, ensuring good interfacial stability between the solid electrolyte and electrode is crucial for enhancing the cycle life. The compatibility and interfacial reactions between the electrolyte and electrode must be carefully addressed to prevent degradation and improve the cycling stability. Recent research efforts have been dedicated to addressing these challenges and progressing the development of SHEs. Various strategies such as doping, composite formation, and interface engineering have been explored to enhance ionic conductivity, stabilize interface, and improve the battery performance. These advancements have led to notable improvements in the electrochemical performance of SHE-based ASSLBs. Herein, the recent advances of SHEs based on Li⁺-conductive oxides and polymer electrolytes for ASSLBs are discussed, including composition, ionic conduction mechanism, and unresolved issues. Especially, the strategies for increasing the ionic conductivity and solving the interfacial issues are presented in detail. Finally, challenges and perspectives of SHEs for ASSLBs are prospected for the future development. This paper offers a comprehensive overview towards SHEs, hoping that it can provide valuable guidance for continued research and development in a wide range of applications including portable electronic devices and electric vehicles.