Studies on capacity loss and capacity fading of nanosized SnSb alloy anode for Li-ion batteries

Nanosized SnSb alloy exhibits much higher reversible capacity as an anode active material for Li-ion batteries. However, rather large capacity loss at the first charge and discharge cycle as well as capacity fading during cycling for pure nanosized alloy has been observed. These phenomena originate from the following factors: the decomposition reaction of surface oxide and the formation of solid electrolyte interphase on the surface of alloy, the irreversible trapping of Li ions by host atoms, serious aggregation of alloy particles during electrochemical cycling, and the existence of an impure phase. Several strategies have been proposed to overcome these drawbacks, including surface modification, addition of dispersant, and coating on stable frame cores, such as mesophase carbon microbeads, to form composite materials. (C) 2001 The Electrochemical Society.