Reversible lithium intercalation in teardrop-shaped ultrafine SnP0.94 particles: An anode material for lithium-ion batteries

Abstract

The preparation and electrochemical structural transformation of a fully reversible new lithium intercalation compound, SnP0.94, which exhibits an excellent life-cycle performance, are discussed. The synthesis of such teardrop-shaped tin phosphide particles, is based on the reaction of tin acetate in a mixed solution of trioctyl phosphine (TOP) and trioctylphosphine oxide (TOPO). Several different shapes of nanoscale metal phosphide particles, such as nanospheres, nanorods, and nanowires, can be formed by controlling the amount and ratio of TOP/TOPO. It was observed that the Li-ion positioning in the interlayer leads to local structural modification around the central Sn atom and prevents the scattering interaction between the central Sn atom and neighboring Sn atom. This material with high reversible capacity, and low average working potential, can be a good candidate to be used as anode material for high-capacity Li secondary batteries.