One-step mild fabrication of branch-like multimodal porous Si/Zn composites as high performance anodes for Li-ion batteries

Multimodal porous Si/Zn composites with controllable components and large porosity are conveniently fabricated through one-step selective dealloying of SiZnAl precursor alloys under green and safe conditions. The as-made Si/Zn composites possess open interconnected three-dimensional (3D) network structure with multiscale pore distributions from scores of nanometer to micro scale. Nanoporous (NP) Si/Zn composites exhibit superior reversible capacity, high rate performance, as well as outstanding cycling stability in virtues of 3D interlinked nanoscale scaffold, massive pore openings, and highly conductive Zn dispersoid. The lithium storage performances of as-made anodes follow the order of Si80Zn20 > Si85Zn15 > Si75Zn25 > Si. The optimal NP-Si80Zn20 delivers the high reversible capacity of 901.8 mAh g−1 at 1000 mA g−1 after continuous cycles as long as 1000 loops. Moreover, the full cell assembling with LiFePO4 cathode and NP-Si80Zn20 anode exhibits a large initial coulombic efficiency of 88.9% and respectable cycling stability. With the merits of excellent energy storage performances as well as green and simple preparation, NP-Si/Zn composite as the promising candidate presents attractive application value for lithium ion batteries.