Rational design of a Si–Sn–C ternary anode having exceptional rate performance

Abstract It is urgent to develop a new anode material that addresses the needs on high energy density as well as high power density of Li-ion batteries to meet the growing demands of high-performance mobile devices and electric vehicles. In this work, a new ternary composite (Si–Sn–C) anode material was designed to achieve exceptional rate performance by scavenging lost Si charge capacity at higher working potential of Sn (~ 0.9 V) under increased current densities. Si and Sn nanoparticles were separately compartmentalized in double-holed carbon nanofibers (Si–Sn–DHCNFs) to elucidate the working potential effect without a kinetic improvement by Sn. Si–Sn–DHCNFs showed high specific capacity (1000 mA h g−1 at 100 mA g−1) and exceptional rate performance (720 mA h g−1 at 10,000 mA g−1). Our work demonstrates that the design of new anode materials is a fruitful route to enhancing the power density of batteries.