Molybdenum trisulfide based anionic redox driven chemistry enabling high-performance all-solid-state lithium metal batteries

Abstract

Currently, all-solid-state lithium-sulfur batteries without polysulfide shuttle effect still can not realize high energy density batteries at room temperature due to the insulating nature and large volume change of sulfur. Herein, ultrafine amorphous molybdenum trisulfide (MoS3) nanoparticles uniformly anchored on the surface of two-dimension reduced graphene oxide (rGO) nanosheets are employed as alternative sulfur cathode for all-solid-state lithium metal batteries, which show comparable discharge plateau and capacity to sulfur-carbon composite electrodes. Compared with lithium ion batteries using organic liquid electrolyte, sulfide solid electrolyte based all-solid-state lithium metal batteries employing amorphous MoS3 undergo reversible anionic redox driven eletrochemical process instead of conversion reaction after initial discharge process. The Li/75%Li2S–24%P2S5–1%P2O5/Li10GeP2S12/rGO-MoS3 all-solid-state lithium metal batteries deliver high reversible capacity of 553.4 mAh g−1 at current density of 0.1 A g−1 after 100 cycles. Even after being cycled at 1.0 A g−1 for 500 cycles, it still shows the discharge specific capacity of 414.1 mAh g−1 with excellent cycling stability. The excellent rate capability and cycle performances could be attributed to the improved electronic conductivity and small volume changes as well as the elimination of soluble polysulfide shuttle. In addition, the electrochemical reaction kinetics and capacity contributions were analyzed via electrochemical impedance spectroscopy and cyclic voltammetry measurements.