Template-directed Prussian blue nanocubes supported on Ni foam as the binder-free anode of lithium-ion batteries

The template-directed Prussian blue analogues supported on nickel foam (denoted as Td-PB/NF) is synthesized through the two-step hydrothermal method. The active materials of 100 nm KNiFe(CN)₆ nanocubes form unique morphology by deposition on leaf-like Ni(OH)₂ nanosheets. Td-PB/NF shows high mass and area specific capacity, excellent rate performance and long cycle life, when used as the anode material for lithium-ion batteries. More specifically, at the current density of 0.1 mA cm⁻², the stable specific capacity can reach 2.1 mA h cm⁻², which is comparable to that of the commercial graphite anode. Even at a current density of 2000 mA g⁻¹, the capacity can still reach 375 mA h g⁻¹ after 1000 cycles. The reaction mechanism of nickel-based Prussian blue as the lithium battery anode electrode is revealed through the characterization of electrode materials in different charge and discharge states. This template-assisted synthesis strategy may provide new ideas for the construction of high-performance lithium-ion batteries and other secondary batteries for Prussian blue-based anode materials.