An Innovative Bi12SiO20 Multistage Cubic Nanospheres Cathode for High‐Performance Bi//Zn Battery

Alkaline Bi//Zn batteries with superb safety, low cost, and high power density are promising candidates for large-scale electrical energy storage. However, their developments are severely limited by the Bi-based cathode as the unsatisfying capacity and cycle life. Herein, an innovative multistage cubic nanospheres Bi12 SiO20 (MCS-Bi12 SiO20 ) is successfully synthesized by a simple calcination method, which shows excellent energy storage performances of superior specific capacity (294 mAh g-1 at 0.5 A g-1 ) and outstanding rate capability (134 mAh g-1 at 12 A g-1 ). When coupled with Zn anode a superior MCS-Bi12 SiO20 //Zn is fabricated, which delivers a high energy density of 247.5 Wh kg-1 at the power density of 375 W kg-1 . Additionally, the MCS-Bi12 SiO20 //Zn battery shows excellent cycle life, which reserves more than 100 % of its original capacity after 5000 cycles. Such performance is higher than previously reported Bi//Zn battery and most other Zn batteries. This is the first example of using Bi12 SiO20 as cathode for RAZBs, which may provide highly promising material towards better Bi//Zn battery.