Vertical bismuth oxide nanosheets with enhanced crystallinity: promising stable anodes for rechargeable alkaline batteries

Abstract

Aqueous alkaline batteries represent an emerging kind of energy storage device, which hold great promise to power electronics with both high energy density and power density. However, their development is severely limited by their anodes which have unsatisfying cycling stability. Herein, we report the facile synthesis of Bi₂O₃ nanosheets vertically aligned on carbon paper, which achieve good electrochemical properties as anodes for alkaline batteries. It is also demonstrated that the crystallinity plays an important role in adjusting the energy storage ability. High crystallinity can efficiently promote the ion diffusion rate within Bi₂O₃, the reversible phase transition and the accommodation of structural strain, which significantly boost the capacity and cycling stability. The as-obtained highly crystalline Bi₂O₃ electrode reached a high specific capacity of 0.14 mA h cm⁻² at 4 mA cm⁻² and achieved outstanding electrochemical stability, with a high capacity retention of 71.4% after 5000 cycles. These findings will provide additional insight into the construction of high-performance anodes for alkaline batteries.