Challenges and Opportunities Facing Solid-State Electrolytes

Abstract

Global energy demand is increasing. Environmental pollution and climate change are also becoming more serious. These problems make the development of energy storage batteries more important. These batteries need high energy density, better safety, and long cycle life. Liquid lithium-ion batteries are mature and widely used. However, they still have several problems. The electrolyte and electrodes may have clear side reactions during battery use. Liquid electrolytes are also easy to burn and easy to evaporate. These problems can reduce battery safety. In contrast, solid-state batteries use solid-state electrolytes instead of liquid electrolytes. This change gives solid-state batteries good potential in safety, stability, and energy density. This paper focuses on solid-state electrolytes. It reviews the material features, performance advantages, main problems, and improvement methods of oxide, sulfide, polymer, and composite solid-state electrolytes. Different types of solid-state electrolytes have different properties. Oxide and sulfide electrolytes are inorganic solid-state electrolytes. They usually have good thermal stability and relatively high ionic conductivity. Polymer electrolytes have better flexibility. Composite electrolytes do a decent job of blending the strengths of organic and inorganic materials, but they still face some common issues. Their ionic conductivity may not be high enough, the interface resistance is often pretty large, and their stability is still somewhat limited. This study helps explain why different solid-state electrolytes perform the way they do, and it also offers some useful pointers for designing better materials and pushing solid-state battery development further.