Enhancing interfacial and internal reaction of sulfide electrode with zinc ions by synergistic effect of phase and structure engineering

Abstract

Although zinc-ion batteries express superior advantages included great safety and cost-effectiveness for grid-level energy storage, the electrode materials are still suffering from structural collapse and depressed kinetics. Fortunately, these defects can be effectively improved by the combination of structure engineering and composition regulation, which is an effective strategy for improving electrochemical reaction kinetics and structure tolerance. Thereof, the Mo-doped Bi2S3 materials with nanorod-linked spherical framework have been constructed in this work. The introduction of Mo-heteroatom can optimize the electronic structure of Bi2S3 for strengthening its conductivity, which contributes to obtain the enhanced reaction kinetics. Furthermore, this trend can be boosted by the design of nanorod-assembled sphere, which effectually reduces the ion diffusion path. In addition, the shaggy sphere possesses the ability of stress dispersion, contributing to maintain the structure integrity during charging/discharging process. As expected, this designed electrode materials exhibit a superior reversibility capacity of 51.0 mA h g − 1 over 1000 cycles at 2000 mA g − 1, and a prominent high-rate capacity of 93.7 mA h g − 1 at the enlarged rate of 6000 mA g − 1. Importantly, this present research will enlighten the combined modification strategy to engineering metal sulfides for high-performance zinc-ion batteries.