Yolk‐Shell NiCo<sub>2</sub>P<sub>X</sub> as a Bidirectional Catalyst for Liquid‐Solid Processes in Advanced Lithium‐Sulfur Batteries
Kun Zhang, Zhenxin Zhao, Zhaowei Ren, Xiaomin Wang
Abstract
Abstract Expedited conversion by using a catalyst has emerged as one of the most effective methods to suppress the shuttle effects in Li−S batteries. The application of accelerating conversion through bidirectional catalysts to address the adverse effects of the shuttle effect on batteries has caused extensive concern. Here, bimetallic nickel‐cobalt phosphide‐based yolk‐shell spheres loaded on reduced graphene oxide (NiCo 2 P X /rGO) are designed as bidirectional catalysts, which integrates the merits of NiCo 2 P X and rGO to facilitate the redox reaction kinetics, resulting in rapid deposition during discharging and fast decomposition during charging of the end products (Li 2 S). The porous yolk‐shell structure synthesized by the anion exchange method exposes more catalytic sites for massive host‐guest interaction. Based on its unique function and structure, the sulfur cathode with NiCo 2 P X /rGO delivers a high capacity of 1238.7 mAh g −1 at 0.1 C and maintains a stable discharge capacity of 561.1 mAh g −1 after 400 cycles at 1 C. This study explores the bidirectional catalysis of polysulfides with bimetallic phosphide materials, which provides a new choice for next‐generation lithium‐sulfur batteries.