Hierarchical bimetallic sulfides Cu3SnS4−Cu2SnS3/N-C: Toward high-rate performance anode for lithium-ion battery

Abstract

The design engineering of a hierarchical bimetallic composite anode is a critical part of the high-performance lithium-ion battery. This study developed a one-step sulfurization route to prepare hierarchical Cu3SnS4−Cu2SnS3 hollow nanocapsules (CTS HNCs) using CuSn(OH)6 nanorods as sacrificial templates. The final Cu3SnS4−Cu2SnS3/N-doped carbon hollow nanocapsules (CTS/N-C HNCs) were obtained by coating the hollow nanocapsules with polydopamine, followed by calcination. As an anode material, the CTS/N-C HNC electrode demonstrated a high capacity (827.8 mAh g−1 at 0.2 A g−1 over 150 cycles), superior long-cycling performance (409.1 mAh g−1 at 1.0 A g−1 over 500 cycles) and outstanding rate performance (average discharge capacity of 374 mAh g−1 at 5.0 A g−1). Hence, the CTS/N-C HNCs composites with a hollow structure, outer assembled nanosheets, and N-doped carbon layer are conducive to controlled volume changes during the intercalation/deintercalation process and accelerate the electron/Li+ transport. Briefly, this research provides a facile strategy for constructing CTS-based hierarchical composites, contributing to the further development of LIBs.