Hierarchical nanoporous nickel alloy as three-dimensional electrodes for high-efficiency energy storage

Hierarchical nanoporous metals with a large surface area and rich pore channels are the sought-after nanostructure for many applications. Here we report a two-step dealloying approach to fabricate a hierarchical nanoporous Ni alloy by utilizing the chemical stability difference of the constituent elements in a multicomponent precursor. Due to the large surface area and high electric conductivity, the hierarchical nanoporous Ni alloy exhibits a high specific areal capacitance of ∼1.11 F cm−2 and volumetric capacitance of 317 F cm−3.