Affiliation:
1. School of Physics and Materials Science Nanchang University Nanchang 330031 China
2. China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan Provincial Key Laboratory of Research on Utilization of Si‐Zr‐Ti Resources Hainan University Haikou 570228 China
Abstract
AbstractMetal thiophosphites have recently emerged as a hot electrode material system for sodium‐ion batteries because of their large theoretical capacity. Nevertheless, the sluggish electrochemical reaction kinetics and drastic volume expansion induced by the low conductivity and inherent conversion‐alloying reaction mechanism, require urgent resolution. Herein, a distinctive porous core–shell structure, denoted as SnPS3@C, is controllably synthesized by synchronously phosphor‐sulfurizing resorcinol‐formaldehyde‐coated tin metal–organic framework cubes. Thanks to the 3D porous structure, the ion diffusion kinetics are accelerated. In addition, SnPS3@C features a tough protective carbon layer, which improves the electrochemical activity and reduces the polarization. As expected, the as‐prepared SnPS3@C electrode exhibits superior electrochemical performance compared to pure SnPS3, including excellent rate capability (1342.4 and 731.1 mAh g−1 at 0.1 and 4 A g−1, respectively), and impressive long‐term cycling stability (97.9% capacity retention after 1000 cycles at 1 A g−1). Moreover, the sodium storage mechanism is thoroughly studied by in‐situ and ex‐situ characterizations. This work offers an innovative approach to enhance the energy storage performance of metal thiophosphite materials through meticulous structural design, including the introduction of porous characteristics and core–shell structures.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Jiangxi Province