In Situ Activation of 3D Porous Bi/Carbon Architectures: Toward High‐Energy and Stable Nickel–Bismuth Batteries

Abstract To achieve high‐energy and stable aqueous rechargeable batteries, state‐of‐the art of anode materials are needed. Bismuth (Bi) has recently emerged as an attractive anode material due to its highly reversible redox reaction and suitable negative operating working window. However, the capacity and durability of currently reported Bi anodes are still far from satisfactory. Here, an in situ activation strategy is reported to prepare a 3D porous high‐density Bi nanoparticles/carbon architecture (P–Bi–C) as an efficient anode for nickel–bismuth batteries. Taking advantages of the fast channels for charge transfer and ion diffusion, enhanced wettability, and accessible surface area, the highly loaded P–Bi–C electrode delivers a remarkable capacity of 2.11 mA h cm −2 as well as high rate capability (1.19 mA h cm −2 at 120 mA cm −2 ). To highlight, a robust aqueous rechargeable Ni//Bi battery based on the P–Bi–C anode is first constructed, achieving decent capacity (141 mA h g −1 ), impressive durability (94% capacity retention after 5000 cycles), and admirable energy density (16.9 mW h cm −3 ). This work paves the way for designing superfast nickel–bismuth batteries with high energy and long‐life and may inspire new development for aqueous rechargeable batteries.