Synergetic enhancement of the electronic/ionic conductivity of a Li-ion battery by fabrication of a carbon-coated nanoporous SnOxSb alloy anode Electronic supplementary information (ESI) available: Fig. S1. Schematic illustration of material preparation. Fig. S2. N2 adsorption-desorption curve. Fig. S3. SEM image of anodes. Fig. S4. TEM images of samples. Fig. S5. Equivalent circuit. Table S1. EIS fitting results. See DOI: 10.1039/c8nr00550h

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-SnO x Sb@C) and its application as an anode in Li-ion batteries (LIBs). The as-fabricated NP-SnO x Sb@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-SnO x Sb@C displays a high capacity (850 mA h g −1 after the 50 th 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. Carbon coated nanoporous SnO x Sb@C alloy has been fabricated and applied as anode in LIBs. It delivers a high capacity of 850 mA h g −1 and high-rate performance by synergetic enhanced electronic/ionic conductivity.