Synergetic enhancement of the electronic/ionic conductivity of a Li-ion battery by fabrication of a carbon-coated nanoporous SnO x Sb alloy anode.

The major obstacles which prohibit the practical applications of alloy-type anodes include insufficient ionic/electronic transportations and structural failures. Herein, we report the fabrication of a carbon-coated nanoporous SnSb alloy (NP-SnOxSb@C) and its application as an anode in Li-ion batteries (LIBs). The as-fabricated NP-SnOxSb@C is characterized by SEM and TEM and demonstrates a bi-continuous nanoporous structure. Amorphous carbon is found to be uniformly coated on the alloy surface. When used as an anode for LIB, NP-SnOxSb@C displays a high capacity (850 mA h g-1 after the 50th cycle) and good rate performance of 664 mA h g-1 at 2000 mA g-1. The improved electrochemical performance is mainly due to a high Li+ diffusion coefficient and low charge transfer resistance between the nanoporous structure and conductive carbon layer. The facile material fabrication process and good electrochemical performance enable the practical utilization of this anode for high-performance LIBs.