We demonstrated the growth of three-dimensional, sponge-like silicon nanostructures networks on chemically-pretreated super-catalytic, nanoporous stainless steel surfaces at low growth temperatures. The as-received stainless steel is turned from a non-catalytic surface into a super self-catalyzing surface via a simple, one-step chemical pretreatment in hydrofluoric acid. The acid etching step creates catalytic nano-islands which expose a different metal composition on the surface of the stainless steel, thus highly promoting the growth of silicon nanostructures without the requirement for an external catalyst. Importantly, the formation of a metal-silicide section, at the base of the silicon elongated nanostructures of the network, confers, due to the reduced expansion and mechanical stability of metal silicides, improved cycling stability to the resulting battery. The large-scale production of this composite material, combined with the high performance of the Li-ion batteries constructed from these anodes, provide a novel paradigm for the next-generation electric vehicles and portable electronics energy solutions.

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