Research progress of cathode/electrolyte interface in solid-state batteries

Abstract

Lithium-ion battery is an ideal power source for portable electronic products, electric vehicles and smart grid. At present, there are still some problems, such as safety and short service life, in lithium-ion batteries using organic liquid electrolyte, however, solid-state batteries (SSB) with non-combustible solid-state electrolyte (SSE) are expected to solve these problems. In principle, nonflammable solid electrolyte can fundamentally prevent the battery from combustion and explosion and only allow lithium ions to flow in the solid electrolyte, which can reduce the occurrence of side reactions. In recent years, with the emergence of several solid electrolytes with high ionic conductivity, the transport of lithium ion in solid electrolytes is no longer a bottleneck. However, the various components in solid-state batteries have different chemical, physical and mechanical properties, as a result, there are many types of interfaces in solid-state batteries, including loose physical contact, grain boundary, chemical and electrochemical reaction interfaces, which may impede the ion transport at the interface. The interface reaction between the cathode and electrolyte is especially complex. It is necessary to understand these complex interfaces and the reaction characteristics. Therefore, the work of exploring and understanding the cathode/electrolyte interface in recent years was reviewed in this paper, and the typical cathode side interface and their unique reaction characteristics in solid-state batteries were summarized.

Keywords

• solid-state battery
• cathode/electrolyte interface
• chemical stability
• electrochemical stabi-lity
• interface modification