Cu6Sn5-TiC-C nanocomposite anodes for high-performance sodium-ion batteries

Abstract

Cu6Sn5 alloy nanoparticles dispersed in a TiC and C conductive matrix have been developed via high energy mechanical milling (HEMM), and the resulting Cu6Sn5-TiC-C nanocomposite has been assessed as anodes for sodium-ion batteries. Composite anodes of Sn-C exhibit poor cyclic performance even with the introduction of 2 vol. % fluoroethylene carbonate (FEC) additive into the electrolyte. In contrast, Cu6Sn5-TiC-C nanocomposite anodes exhibit stable cycle life corresponding to a capacity retention of similar to 80% at 40 cycles and high-rate performance with a capacity retention of similar to 62% at 3000 mA g(-1). These superior performance metrics is ascribed to the well-developed electrochemically active nanocrystalline material (Cu6Sn5) as well as a hybrid conductive matrix (TiC and C). The incorporation of 2 vol. % FEC additive into the electrolyte further improves the performance of Cu6Sn5-TiC-C nanocomposite to display a capacity retention of similar to 94% at 250 cycles and high-rate capacity retention of similar to 82% at 5000 mA g(-1), which are attributed to the formation of a thin and stable SEI layer in presence of FEC. (C) 2015 Elsevier B.V. All rights reserved.