Advances in Selenium Sulfides Cathodes for Lithium/Selenium–Sulfur Batteries

The global energy crisis has sparked extensive research into rechargeable battery materials to address the growing demand for energy. High-capacity electrode materials are central to achieving significant advances in energy density. Lithium/selenium–sulfur (LSeSBs) batteries have emerged as an exciting alternative to lithium–sulfur and lithium–selenium systems, harnessing the combined benefits of sulfur's high capacity and selenium's enhanced electrical conductivity. This integration has established selenium sulfides (SexSy) as an encouraging category of cathode substances. Recent years have seen a flurry of research, yielding significant findings in this domain. This review encapsulates the current state of LSeSBs battery research with a particular focus on pioneering work in SexSy cathode materials. It delves into the reaction mechanism and factors contributing to capacity decay, examining the relationship between performance and structure across various cathode configurations, including different Se/S ratios and a multitude of hosts of carbons, conducting polymers, and doped carbons. This review sheds light on the complex relationships between the ratios of selenium and sulfur in SexSy cathodes, their respective strengths and weaknesses, and innovative engineering solutions that contribute to the performance of LSeSBs.