Structure and Properties of Electrodeposited Sn-Co Alloy Electrodes as Anode Material for Lithium-Ion Secondary Batteries

Abstract

The Sn-Co alloy deposits were prepared by electroplating.The structure and electrochemical performance of the electroplated Sn-Co alloys have been investigated in detail.Experimental results show that the porous Sn-Co alloy film exhibits hexagonal solid solution,with Sn as the solvent, Co as the solute.The texture of the Sn-Co alloy coating exhibits(110) preferred orientation.Electrochemical tests show that the porous Sn-Co alloy coating electrodes can deliver a discharge capacity of 643mAh/g in the first cycle.At the 20~(h) cycle the charge was 461mAh/g.At initial charge curve the irreversible capacity is probably associated to a combination of processes,which may include the reduction of small amount of tin dioxide and cobalt oxide on electrode surface,solvent decomposition and the formation of a passivating film on the electrode surface.The porous Sn-Co alloy electrodes can partly accommodate the volume expansion and phase transition during cycling,and would improve the cycle life of the electrode.They are also beneficial to diffusion of Li into /out of macroporous materials,and improve dischargeability/chargeability at charge discharge cycle.