Study of Li insertion mechanisms in transition metal antimony compounds as negative electrodes for Li-ion battery

MSb (M = Ni, Co, Fe, Mn) alloys with a NiAs type structure were synthesized by ceramic route and evaluate as a negative electrode material for rechargeable lithium batteries. Electrochemical tests demonstrated that initial charge and discharge capacities of this materials were ca. 390 and 330 mAh g−1, respectively. Ex situ XRD of MnSb electrodes showed that LiMnSb and Li3Sb were successively formed during lithium insertion. The 121Sb Mössbauer spectra show that the insertion mechanism during discharge involves the formation of several lithium-containing compounds such as LiMnSb, Li3Sb with manganese extrusion. During the subsequent charge a more complex mechanism occurs involving MnSb, modified LiMnSb alloy and metallic Sb formation.