CHAPTER 4. Solid Electrolytes for Lithium Metal and Future Lithium-ion Batteries

All solid-state lithium batteries (ASSLBs), with the elimination of flammable liquid solvents and possible safe use of high capacity electrodes, are believed to unlock the bottlenecks in energy density and safety for current Li-ion batteries. Being sandwiched between a highly reductive anode and an oxidative cathode, the nature of solid electrolytes (SEs) plays a pivotal role in dictating the electrochemical performance of ASSLBs. In this chapter, a brief introduction to the transport properties of SEs and a detailed survey of the status of research on SEs are presented. In particular, attention is paid to the very recent interesting findings and breakthroughs in the field of SEs, instead of screening/analyzing the physicochemical and electrochemical properties of reported electrolytes, which have been scrutinized in recently published reviews. Furthermore, remarks and thoughts on the existing challenges and future outlook are depicted.