Exploring the electrochemistry of Al3+ ion in amorphous Bi4V2O11 for rechargeable aqueous aluminum-ion battery

Abstract

Amorphous materials are receiving considerable interest in rechargeable batteries, primarily due to their inherent isotropic properties and abundant defects, which facilitates ion diffusion and make them highly suitable for rechargeable batteries. However, there is a significant lack of study on amorphous materials for rechargeable aqueous aluminium-ion batteries. Herein, we investigate the electrochemical activity of amorphous Bi4V2O11 for Al3+ ion storage in aqueous electrolyte for the first time. Through experimental analysis, we demonstrate that amorphous Bi4V2O11 is highly feasible in storing Al3+ ions compared to crystalline Bi4V2O11 in an aqueous electrolyte. A stable discharge capacity of 119 mAh g-1 is achieved over 200 cycles in 1 M Al(ClO4)3 aqueous electrolyte at a current rate of 1000 mA g- 1 , along with an excellent rate capability. In contrast, crystalline Bi4V2O11 only delivers 59 mAh g-1 of discharge capacity at the same current rate. Ex-situ XRD, SEM, and XPS investigations offer insights into the possible storage mechanism. Overall, this work not only indicates the suitability of amorphous Bi4V2O11 as a reliable electrode material for aluminum-ion battery but also offers valuable insights for the development of other high-capacity and long-lasting aqueous batteries utilizing amorphous materials.