Simple design of a Si–Sn–C ternary composite anode for Li-ion batteries

Abstract

Previous research established that Si–Sn–C ternary composite electrodes composed of carbon nanofibers (CNFs) having robust double-hole structures filled with Si and SnOx nanoparticles displayed excellent electrochemical performance due to the thermodynamic contribution of Sn. This study reports simple and highly commercial ternary composite electrodes. By electrospinning and subsequent thermal treatment, Si and Sn nanoparticles were dispersed in solid CNFs to form Si–Sn–SC nanofibers, or they were incorporated into a core of hollow CNFs to form Si–Sn−HC nanofibers. The rate performances of these two ternary electrodes displayed quite good retention because of the ternary composition, but their rate performances differed at high current densities (5000 and 10,000mAg–1); the core/shell structure of the Si–Sn−HC nanofibers was more beneficial for rate performance retention than the Si–Sn–SC nanofibers having intimate electrical contact of Sn and Si with the carbon matrix. Improved cycling performances also resulted from the structure of the Si–Sn−HC nanofibers. The core/shell structured Si–Sn–C ternary composite anode thus has an advantageous structure for high-power Li-ion batteries having long-term stability.