Halloysite modulated MoC-MoN heterojunction for high-performance LiS Batteries

Abstract

Transition metal carbide-nitride heterojunctions have gained great attention in LiS batteries for overcoming the issues such as polysulfide dissolution, poor electrical conductivity of the cathode, and sluggish electrode reaction kinetics. However, precisely designing and synthesizing these potentially important materials is still challenging. Herein, a novel strategy that employs halloysite for MoC-MoN heterojunction with a precisely regulated interface (HNT/MoC-MoN) is proposed. The results show that halloysite surfaces abundant in hydroxyl groups can induce the formation of MoC-MoN heterojunction via enhancing charge transfer at the interface between halloysite and MoC-MoN. The optimized formation of the MoC-MoN heterojunction accelerates the electron migration and the conversion kinetics of lithium polysulfide (LiPSs). By optimizing the design, the synthesized HNT/MoC-MoN composite demonstrates excellent electrochemical performance in LiS batteries, achieving an initial specific capacity of 1100 mAh g⁻¹ at 0.2C and maintaining a capacity of 605 mAh g⁻¹ after 300 cycles. This work may provide valuable insights for the application of natural minerals in LiS batteries.