Ni@O-doped carbon Mott-Schottky heterojunctions to enhance sulfur conversion kinetics

Abstract

The practical application of lithium-sulfur batteries (LSBs) is hindered by the sluggish redox kinetics of polysulfides. The authors propose that a Ni@OC Mott-Schottky heterojunction catalytically accelerates sulfur conversion reactions. The experimental results reveal that benefitting from a self-generated built-in electric field, the charge redistribution at the Ni@OC heterointerface accelerates electron transfer and enhances catalytic activity contributing to the conversion kinetics of polysulfides. Therefore, the cells assembled with Ni@OC heterojunction display an excellent rate performance (the capacity 640.4 mAh∙g−1 at 3 C) and a high capacity of 1026.6 mAh∙g−1 under the lean electrolyte (E/S = 5.0 μL∙mg−1) conditions. The proposed Mott-Schottky heterostructure provides a favorable reference and advanced guidance for high-capacity lithium-sulfur batteries.