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

[Display omitted] • Core/shell structured Si–Sn–C ternary composite anode was fabricated through mass-producible coaxial electrospinning. • Carbon shell effectively accommodated Si and Sn volume expansion and prevented electrochemical performance deterioration. • Core/shell structured Si–Sn–C ternary anode exhibited 20% higher capacity at 10C than that of solid Si–Sn–C composite. • Excellent rate performance was driven by thermodynamically forced delithiation of Si owing to higher working potential of Sn. Previous research established that Si–Sn–C ternary composite electrodes composed of carbon nanofibers (CNFs) having robust double-hole structures filled with Si and SnO x 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 10,000 mA g^–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. [ABSTRACT FROM AUTHOR]