Achieving high-capacity and long-life K+ storage enabled by constructing yolk-shell Sb2S3@N, S-doped carbon nanorod anodes

As promising anode candidates for potassium-ion batteries (PIBs), antimony sulfide (Sb2S3) possesses high specific capacity but suffers from massive volume expansion and sluggish kinetics due to the large K+ insertion, resulting in inferior cycling and rate performance. To address these challenges, a yolk-shell structured Sb2S3 confined in N, S co-doped hollow carbon nanorod (YS-Sb2S3@NSC) working as a viable anode for PIBs is proposed. As directly verified by in situ transmission electron microscopy (TEM), the buffer space between the Sb2S3 core and thin carbon shell can effectively accommodate the large expan-sion stress of Sb2S3 without cracking the shell and the carbon shell can accelerate electron transport and K+ diffusion, which plays a significant role in reinforcing the structural stability and facilitating charge transfer. As a result, the YS-Sb2S3@NSC electrode delivers a high reversible K+ storage capacity of 594.58 mA h g(-1) at 0.1 A g(-1) and a long cycle life with a slight capacity degradation (0.01% per cycle) for 2000 cycles at 1 A g(-1) while maintaining outstanding rate capability. Importantly, utilizing in in situ/ex situ microscopic and spectroscopic characterizations, the origins of performance enhancement and K+ storage mechanism of Sb2S3 were clearly elucidated. This work provides valuable insights into the rational design of high-performance and durable transition metal sulfides-based anodes for PIBs (C) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

This study proposes a yolk-shell structured Sb2S3 confined in N, S co-doped hollow carbon nanorod as a promising anode for potassium-ion batteries. The structure effectively addresses the challenges of volume expansion and sluggish kinetics, resulting in outstanding cycling performance and rate capability. The mechanism of performance enhancement and K+ storage of Sb2S3 is elucidated through in situ/ex situ microscopic and spectroscopic characterizations.