Dually Sulphophilic Chromium Boride Nanocatalyst Boosting Sulfur Conversion Kinetics Toward High‐Performance Lithium–Sulfur Batteries

Abstract

Abstract The sluggish kinetics of sulfur conversions have long been hindering the implementation of fast and efficient sulfur electrochemistry in lithium–sulfur (Li–S) batteries. In this regard, herein the unique chromium boride (CrB) is developed via a well‐confined mild‐temperature thermal reaction to serve as an advanced sulfur electrocatalyst. Its interstitial‐alloy nature features excellent conductivity, while the nano‐lamination architecture affords abundant active sites for host‐guest interactions. More importantly, the CrB nanocatalyst demonstrates a dual sulphophilicity with simultaneous Cr─S and B─S bondage for establishing strong interactions with the intermediate polysulfides. As a result, significant stabilization and promotion of sulfur redox behavior can be achieved, enabling an excellent Li–S cell cyclability with a minimum capacity fading rate of 0.0176% per cycle over 2000 cycles and a favorable rate capability up to 7 C. Additionally, a high areal capacity of 5.2 mAh cm−2, and decent cycling and rate performances are still attainable under high sulfur loading and low electrolyte dosage. This work offers a facile approach and instructive insights into metal boride sulfur electrocatalyst, holding a good promise for pursuing high‐efficiency sulfur electrochemistry and high‐performance Li–S batteries.

Keywords

• chromium boride
• dual sulphophilicity
• electrocatalysis
• lithium‐sulfur batteries