Cathode host engineering for non-lithium (Na, K and Mg) sulfur/selenium batteries: A state-of-the-art review

Abstract

Sulfur and selenium have been paid more and more attention in energy storage systems because of their high theoretical specific gravimetric and volumetric capacities. With the increasing scarcity of lithium resources, secondary batteries made of sulfur and selenium coupled with other alkali metal/alkaline earth metals (e.g. Na, K, Mg) are expected to play a vital role in future production and human life. Due to the volume expansion, poor conductivity and shuttle effect, the structure design of cathode, as one of the important roles in metal-S/Se batteries, has always been a hot and difficult point. In the review, various host materials of S and Se are clarified and discussed. Typically, carbonaceous materials are the most widely used hosts, while polar materials are becoming more and more popular in metal-S/Se batteries. Through a comprehensive overview, it is hoped that previous research experiences can provide further reference and guidance for the sustainable development of metal-S/Se batteries.