Spherical nano-SnSb/MCMB/carbon core-shell composite for high stability lithium ion battery anodes

A novel multi-step design of spherical nano-SnSb/MCMB/carbon core-shell composite for high stability and long life lithium battery electrodes has been introduced. The core-shell composite was successfully synthesized via co-precipitation and subsequent pyrolysis. The resultant composite sphere consisted of nanosized SnSb alloy and mesophase carbon microbeads (MCMB, 10 μm) embedded in a carbon matrix pyrolyzed from glucose and petroleum pitch, in which the MCMB was treated to be the inner core to offer mechanical support and efficient electron conducting pathway. The composite material exhibited a unique stability with a retention discharge capacity rate of 83.52% with reversible capacity of 422.5 mAh g−1 after 100 cycles and a high initial coulombic efficiency of 83.53%. The enhanced electrochemical performance is attributed to the structural stability of the composite sphere during the charging-discharging process.