Atomically Dispersed Ni Site Catalysts Accelerating Sluggish Sulfur Redox Kinetics in Nonaqueous Zn‐S Batteries

Le résumé fourni par la source

ABSTRACT Aqueous zinc‐ion batteries are hindered by parasitic water‐induced side reactions and a narrow electrochemical stability window. Transitioning to nonaqueous electrolytes offers a solution to these challenges, yet sluggish redox kinetics and poor sulfur conversion efficiency remain significant obstacles for practical Zn─S systems. Herein, we report a Ni single‐atom catalyst supported on Ketjen black (Ni‐SAC) as a high‐efficiency sulfur host for nonaqueous Zn─S batteries. By utilizing stable 1 m Zn(CF 3 SO 3 ) 2 in acetonitrile electrolyte, we achieve highly reversible Zn plating/stripping with a Coulombic efficiency up to 99.9%. Consequently, the Ni‐SAC cathode delivers a high initial discharge capacity of 1068.4 mAh g −1 with improved long‐term stability over 400 cycles at 0.05 A g −1 , and 559.4 mAh g −1 over 150 cycles at 0.2 A g −1 . Notably, the cell achieves an areal capacity exceeding 4 mAh cm −2 under high sulfur loading up to 7.0 mg cm −2 . As validated by DFT calculations, Ni‐N 4 active sites significantly lower activation energy barriers for rate‐limiting steps in the sulfur redox reaction. Furthermore, the efficacy of Ni‐SAC is demonstrated by operando wide‐angle X‐ray scattering analysis capturing reversible S 8 /ZnS phase transformation and post‐mortem analysis revealing formation of robust ZnF 2 ‐rich cathode‐electrolyte interphase. This study provides a strategy for bridging atomic‐scale catalysts with macroscopic performance in nonaqueous Zn─S chemistries.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.