Integrated Structure of Tin-Based Anodes Enhancing High Power Density and Long Cycle Life for Lithium Ion Batteries

Tin-based materials have been considered as promising anode materials due to their advantages including high specific capacity, abundant resources, and low toxicity. Unfortunately, it has remained an intractable challenge for reasonable design with improved power density and long-term cycle performance for Li ion batteries because of the huge irreversible volume change during the alloying/dealloying process. Herein, an integrated electrode is designed by in situ growing SnSSe on the graphene sheet, followed by self-assembly and multiscale coated with conductive carbonized polyacrylonitrile. Pleasantly, dynamic evolution of integrated electrode thickness during cycles is in situ monitored by dilatometer, which exhibits effectively suppression of the thickness change to a low level with great reversibility (38.2% expansion ratio) compared with the pristine SnSSe electrode (161.8% expansion ratio) in the first cycle. Moreover, the electrochemical impedance of the integrated electrode shows a great stability after 500 cycles. As a result, the integrated electrode of SnSSe/GR@C shows a great rate performance (518.4 mA h g(-1) at 5.0 A g(-1)) and stable cycle life (capacities retention of 107.1% at 5.0 A g(-1) after 850 cycles). This work offers an innovative strategy for the development of high-performance tin-based anodes.