Sn-Ca amorphous alloy as anode for lithium ion battery

Amorphous Sn-Ca alloys were synthesized by solution technique using NaBH4 a s the reducing agent. The particles are found to be homogeneous with size s imilar to4 mum. The alloys were tested using Li metal as counter electrode. The capacity has been found to be 400 mAh/g and 62% of it was retained aft er 70 charge-discharge cycles. The ex situ XRD technique was used to illust rate the progress of Li intercalation. Cyclic voltammograms show that the t wo peaks located at 0.6 and 0.2 V, respectively, correspond to the charge a nd discharge plateaus. The observation of voltage plateau at about 1.0 V co nfirms the formation of solid electrolyte interface (SEI) on the surface of the anode. The intercalation of Li is through the formation Li5Sn2 phase, which was confirmed by HRTEM. (C) 2001 Elsevier Science B.V. All rights res erved.