Sn–Ca amorphous alloy as anode for lithium ion battery

Abstract

Amorphous Sn–Ca alloys were synthesized by solution technique using NaBH 4 as the reducing agent. The particles are found to be homogeneous with size ∼4 μm. 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 after 70 charge–discharge cycles. The ex situ XRD technique was used to illustrate the progress of Li intercalation. Cyclic voltammograms show that the two peaks located at 0.6 and 0.2 V, respectively, correspond to the charge and discharge plateaus. The observation of voltage plateau at about 1.0 V confirms the formation of solid electrolyte interface (SEI) on the surface of the anode. The intercalation of Li is through the formation Li 5Sn 2 phase, which was confirmed by HRTEM.