A rational design of V2O3/VN heterostructures with high-efficient chemisorption and electrocatalytic activity for polysulfides in lithium-sulfur batteries

Abstract

Polysulfide shutting between cathode and anode and sluggish redox of solid-liquid-solid conversion largely impede the commercial applications of lithium-sulfur (Li–S) batteries. Herein, a novel V2O3/VN heterostructure has been designed as an efficient adsorbent and catalyst to promote polysulfide trapping and redox kinetics. Such synchronous advantages of each part of V2O3/VN can efficiently alleviate shuttling and accelerate polysulfide conversion, thus improve electrochemical performances. Benefited from this synergistic effect, the assembled full cells with V2O3/VN heterostructure exhibit an initial capacity of about 1100 mAh g−1 at 0.1C and an outstanding rate performance of 612 mAh g−1 at 2C. After 100 cycling tests at 0.2C, the specific capacity still maintains about 670 mAh g−1. Our approach would provide a new viewpoint of designing efficient sulfur additives to improve the redox kinetics for high-performance lithium-sulfur batteries.