Copper nanowall array grown on bulk Fe–Co–Ni alloy substrate at room temperature as lithium-ion battery current collector

Large-scale copper nanowall array on the bulk Fe–Co–Ni alloy substrate has been prepared in aqueous solution at room temperature via an electroless deposition method. The thickness of the nanowalls is about 15 nm. A possible growth mechanism of the nanowalls was proposed. The effects of reaction temperature, reaction time and the amount of critical agent (Fe3+) on the morphology and crystalline phase of the nanowalls were investigated. Furthermore, the electrochemical performance of Sn film supported on the as-prepared copper nanowalls current collector is enhanced in comparison with that on the commercial copper foil when used as anode for Li-ion batteries with the operating voltage window of 0.01–2.0 V (vs. Li). After 20 cycles, the discharge capacity of Sn–Cu nanowalls anode still remained 365.9 mAh g− 1, that is, 40% retention of the reversible capacity, while the initial charge capacity of Sn film cast on commercial Cu foil was 590 mAh g− 1, dropping rapidly to 260 mAh g− 1 only after 10 cycles.