A Heterostructured Gel Polymer Electrolyte Modified by MoS2 for High-Performance Lithium-Sulfur Batteries.

Abstract

In Li-S batteries, the shuttle effect of polysulfide lithium (LiPS) on the cathode side and the growth of lithium dendrites on the anode side are two major problems that lead to an insufficient cycle life. Herein, in light of the challenges brought on by the different chemical environments on both sides of Li-S batteries, a heterostructured poly(ethyl acrylate-co-ionic liquid) gel electrolyte with a single-sided electrocatalytic reduced graphene oxide/MoS2 coating (MoS2@rGO-GPE) was developed in order to assemble a high-performance Li-S battery with a self-supporting graphene sulfur cathode. In such a device architecture, there is multiposition suppression of the shuttle effect; that is, the confinement of the graphene foam, the catalysis of the MoS2 composite, and the capture of the gel polymer electrolyte. Our results show that the ionic conductivity of the heterostructured electrolyte is 1.98 mS cm-1, and the Li ion transference number reaches 0.81. The assembled lithium-sulfur battery displays a high initial discharge capacity of 1027 mAh g-1 at 0.1 C, superior cycle stability (80% capacity retention after 500 cycles), and excellent rate performance. This design strategy provides a valuable route for the development of high-performance lithium-sulfur batteries.