全固态锂硫电池中界面问题的研究现状

Due to the high theoretical specific capacity of lithium metal anodes and the high safety of solid electrolytes, all-solid-state lithium-sulfur batte-ries (SSLSBs) are increasingly favored by researchers. Compared with liquid lithium-sulfur batteries, the biggest difference of SSLSBs is that the solid electrolyte replaces the liquid electrolyte. The solid electrolyte material is of high safty because of non-flammable of solid electrolyte. In addition, the optimized solid electrolyte exhibits sufficient mechanical strength to effectively suppress the generation of lithium dendrites. SSLSBs also have greater advantages in terms of product preparation and transportation. However, the high density solid-solid interfaces in SSLSBs may induce a series of problems such as interface resistance and volume distortion during cycling, which restricts the commercial application of SSLSBs. Thus, researchers have conducted extensive research on the solid-solid interfaces in recent years, including continuously improving the preparation process, characterizing the interface evolution process, and simulating and verifying the ion migration path. At present, some SSLSBs have realized commercial application. SSLSBs mainly include sulfur-containing positive electrodes, lithium metal negative electrodes and solid electrolytes. Solid electrolytes are mainly divided into electrodeless solid electrolytes and organic solid electrolytes. Therefore, the researches on the interface of solid electrolyte can also be categorized in two types. One type is the internal interface of solid electrolyte, including the interface between inorganic electrolyte and inor-ganic electrolyte or the interface between inorganic and organic electrolyte. Another type mainly includes the interface between the solid electrolyte and the electrodes, which has a great influence on the chemical stability, volume stability and electronic ion conductivity of the battery. In recent years, researchers have found that the interface can be effectively improved via changing the mixing method, particle size, porous matrix and volumetric pressure. Besides, with the development of characterization technology, more and more in-situ interface characterization technologies provide more intuitively changing state of the interface. This article systematically summarizes the problems and research status of the internal and external interfaces of SSLSBs, and discusses the future development trends and research priorities of SSLSBs.