Functional mechanism analysis and customized structure design of interlayers for high performance Li-S battery

Lithium sulfur (Li-S) battery is one of the most potential energy storage battery systems due to its high theoretical capacity and energy density. However the "shuttle effect" originating from the lithium polysulfide and the Li dendrite growth and deterioration, hindering its fast development and commercialization process. And in the past five years, the use of interlayers in Li-S batteries significantly improves the specific capacity of batteries and restrains lithium dendrites. In this review, the fundamental studies and current development trends for interlayers are presented and reviewed mainly including cathodic and anodic interlayers with detailed function mechanism and customized structure designs. For cathodic interlayers, the function mechanism includes physical barrier & adsorption, chemical reaction & adsorption and catalytic conversion. For anodic interlayers, they can be mainly divided into physical barrier, induced growth, nucleation mechanism and their combination. The customized structure designs includes nanoscale, porous and bionic structures even physical and chemical properties of interlayers. The current research directions and challenges associated with the application of the interlayers of batteries and the future perspectives for this class of interlayers are concluded in the end. This discussion and proposed strategies will offer avenues to the actual utilization of Li-S batteries in near future.