Zn3P2 has been studied as an anode material for lithium-ion batteries. Electrochemical studies demonstrate that the initial discharge and charge capacities are 1056 and 710 mAh g-1, respectively. The discharge-charge reaction mechanism of lithium with Zn 3P2 is analyzed by ex situ X-ray diffraction. On initial discharge, LiZn alloy is formed in a matrix of Li3P. Upon charge, LiZn alloy is transformed completely into Zn metal and Li3P is converted partially to P, which reacts with Zn to form the original Zn 3P2 phase. The reversible capacity of Zn3P 2 is improved when cycled in the limited voltage window. © 2005 Elsevier B.V. All rights reserved.