We report the electrochemical synthesis of iron phosphide films used as anodes of lithium secondary batteries. The phosphorus content in the film was increased to a level almost equal to that of Fe (corresponding to a FePy composition with 0.85 < y < 0.91) through the selective electrochemical dissolution of Fe and Fe-rich phase from the electroplated film. The as-deposited film exhibited a dense structure characterised by numerous submicron-sized nodules in contact with each other, and maintained its overall mechanical integrity even after the selective dissolution. The as-deposited and the selectively etched films with high P content were tested as anodes of lithium secondary batteries. The performance of the selectively etched films far exceeded that of the as-prepared films. In particular, a 500-nm-thick film maintained a reversible discharge capacity greater than 420 mA h g(-1) after 30 cycles. No specific physical damage was observed in the film after the cycling tests. (C) 2016 Elsevier Ltd. All rights reserved.