context: Ni foams, typical 3D porous substrates, are extensively employed as current collectors/supports in energy storage devices, because they not only afford large surface areas and easy electrolyte access, but also enable efficient ion diffusion and charge transfer. For example, Chen and coworkers designed hierarchical micro-nano sheet arrays of nickel–cobalt double hydroxide supported on Ni foam (NiCo-DH) via an etching-deposition-growth strategy. The corresponding Ni–Zn battery with a NiCo-DH electrode as the cathode delivered a high specific capacity of 329 mA h g−1. Wang et al. synthesized a Co3O4@NiV-LDH nanowires array grown on the surface of a Ni foam with a hierarchical structure. When used as the cathode, the assembled battery demonstrated a satisfactory capacity of ∼1.25 mA h cm−2. Despite the favorable electrochemical performance of these cathodes, the complicated or multi-step preparation processes required substantially impede their industrial application. Furthermore, the ex situ formed active materials deposited on the Ni foam are unavoidably peeled off during long-term charge–discharge tests, which may cause trouble for the cyclic stability of zinc batteries.
answer: Co3O4@NiV-LDH