Synthesis and Electrochemical Behaviour of Tin Phosphate as Anode Material For Lithium Ion Cells

This study aims to explore the possibility of tin phosphate application material in lithium ion cells. Two batches of tin phosphate have been synthesized via a chemical route where one batch was synthesized with the sodium dodecyl sulfate surfactant to produce meso structured tin phosphate and the other was synthesized without the surfactant. From x-ray difraction (XRD) analysis, the synthesized tin phosphate which was calcined at 500oC showed crystalline characteristic whereas that of meso structured tin phosphate maintained and amorphous nature. Electrochemical measurements showed reversible lithium ion reaction upon charging and discharging of the tin phosphate anode with the potential range of 0-2V vs Li+/Li. Upon the first cycle, tin phosphate delivered reversible capacity of 272mAh/g whereas meso structured tin phosphate delivered that 590mAh/g. Substantial capacity losses and fading upon further cycling was experienced by both anode due to the formation of irreversible phase and restriction in the reversible lithium - tin formation.It is believed that meso structure tin phosphate anode exhibited better capacity retention because its porous structure which minimized the effect of volume changes experienced by the anode during the charge - discharge cycling process.