Advance of Metal Compound Cathodes in Lithium Sulfur Batteries

Abstract

With the rapid development of technology, people’s demand for energy is increasing day by day. Many energy devices electric vehicles and other technological products require high-energy lithium secondary batteries to operate. Higher electrochemical energy per unit volume and lower manufacturing cost than lithium batteries are the characteristic advantages of lithium sulfur (LiS) batteries. At the same time, it is environmentally friendly. The global reserves of elemental sulfur are also very abundant, and the cost is low. Therefore, LiS batteries have become one of the most promising secondary batteries in the future. However, LiS batteries also suffer from issues such as poor conductivity of the active substance sulfur, shuttle effect, volume expansion, and lithium dendrites. Research has found that the application of composite materials of metal compounds and sulfur in the cathode of LiS batteries can effectively limit the shuttle effect and poor conductivity of LiS batteries. It can effectively adsorb polysulfides generated in the reaction, optimize the electric performance of cathode sulfur, strengthen the rate performance and cycle stability of lithium ion battery, as well as reduce capacity degradation, significantly improving their electrochemical performance. This article reviews the research progress on the application of metal compounds, mainly metal oxides and metal sulfides, in the cathode of LiS batteries. It explores how this application can suppress shuttle effects and slow down capacity degradation and summarizes and looks forward to its development.