To develop next-generation lithium-ion batteries (LIBs) with novel designs, reconsidering traditional materials with enhanced cycle stability and excellent rate performance is crucial. We herein report the successful preparation of three-dimensional (3D) composites in which spilt Sn-Cu alloys are uniformly dispersed in an amorphous carbon nanofiber matrix (Sn-Cu-CNFs) via one-step carbonization-alloying reactions. The spilt Sn-Cu alloys consist of active Cu6Sn5 and inactive Cu3Sn, and are controllable by optimization of the carbonization-alloying reaction temperature. The 3D carbon nanofiber framework allowed the Sn-Cu-CNFs to be used directly as anodes in lithium-ion batteries without the requirement for polymer binders or electrical conductors. These composite electrodes exhibited a stable cyclability with a discharge capacity of 400 mA h g (1) at a high current density of 1.0 A g (1) after 1200 cycles, as well as an excellent rate capability, which could be attributed to the improved electrochemical properties of the Sn-Cu-CNFs provided by the buffering effect of Cu3Sn and the 3D carbon nanofiber framework. This one-step synthesis is expected to be widely applicable in the targeted structural design of traditional tin-based anode materials. (C) 2016 Elsevier Ltd. All rights reserved.