Synthesis of confinement structure of Sn/C-C (MWCNTs) composite anode materials for lithium ion battery by carbothermal reduction

A composite anode material was prepared with confined tin into multiwall carbon nanotube by carbothermal reduction. The morphology and structure of Sn/C (nature graphite) and Sn/C-C (nature graphite + multiwall carbon nanotube) were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was revealed that the additive of MWCNT was a crucial factor to improve Sn /C composite anodes for cyclability and reversible capacity. Volume changes and morphological changes in Sn can be reduced by encasing MWCNT in a carbonaceous material that has sufficient flexibility to act as a buffer. Electrochemical performance test shows that the charge capacity of the Sn/C-C (NG + MWCNT) electrode in the fiftieth cycle was 400 mAh/g, which was higher than that of the Sn/C (NG) electrode. After 50 cycles, the retention of the Sn/C-C electrode and the Sn/C electrode was 80% and 63%, respectively.

Research Highlights
► The cyclability of Sn/C electrodes can be improved by adding MWCNTs.
► MWCNTs provided a reliable matrix space that effective suppress the stress of volume change during charge/discharge.
► Improvement of the anode performance due to the MWCNT loading also includes: (1) the active material utilization was improved; (2) the electro-conductivity was enhanced.