Operationally Robust Li–S Batteries at High Current Density Enabled by Metallic, Dual Sulfurphilic Nickel Boride

Abstract

Achieving high sulfur loading and robust cycling in lithium–sulfur (Li–S) batteries under a high current density is challenging. Employing metallic catalysts to improve the charge transfer and the polysulfide lithium polysulfide (LiPSs) conversion within the sulfur cathode under a high current with a high sulfur loading represents a promising approach. This study explores metallic nickel boride (NiB) as a catalyst to enhance charge transfer and LiPS conversion. Theoretical and experimental results reveal that NiB accelerates sulfur redox kinetics, significantly improving the battery performance. With a sulfur loading of 5 mg cm^–2 cycled at 0.5 C, the NiB-based battery achieved a discharge capacity of 1239 mAh g^–1, retaining 83.2% after 150 cycles. Even at a current density of 14.89 mA cm^–2, it maintained a capacity of 590 mAh g^–1 with a low decay rate of 0.07%. This approach highlights the potential of metal boride catalysts for practical Li–S battery applications.