Synergistic structural engineering of 3D printed matchable electrodes for long-life rechargeable nickel–bismuth batteries

Abstract

Aqueous rechargeable alkaline batteries have attracted increasing attention due to their reliable safety, low cost and high electrochemical potential. However, it remains challenging to construct remarkable rechargeable batteries with desirable electrode architectures and optimized electrochemical mechanisms. Herein, 3D printed high-loading bismuth-based anodes with synergistic enhancement of three-dimensional interconnection network structure and oxygen vacancies is achieved, for which intrinsic battery charge storage mechanism is in-depth unveiled. The synergistic structural engineering significantly enhances the overall charge carrier transport of 3D printed nickel-bismuth batteries, as evidenced by the conductivity of a single-wired electrode, enabling nickel-bismuth batteries to achieve a high areal capacity of 0.17 mA h cm−2 at 6 mA cm−2, a high energy density of 97.92 μWh cm−2 and a power density of 6.41 mW cm−2. Moreover, superior cycling stability is obtained. Ex situ characterization results reveal that Bi2O2.33 undergoes a phase transition after the initial charge and discharge, while the subsequent cycles rely on the reversible phase transition mechanism between Bi and Bi2O3 for basic charge storage. The exceptional performance and revealed mechanism of 3D printed batteries offer novel ideas and understanding for constructing future rechargeable nickel-bismuth batteries with state-of-the-art behaviors.