An electrochemical study on bismuth oxide (Bi2O3) as an electrode material for rechargeable aqueous aluminum-ion battery

The global research efforts for identification of electrode materials for high energy and high power density rechargeable aqueous/non-aqueous aluminum-ion batteries have gained unprecedented momentum in contemporary times. Herein, we exclusively report the Al3+ ion electrochemistry of Bi2O3 in aqueous electrolyte for the first time. While investigating the electrochemical performance of Bi2O3, we demonstrate a unique method to simultaneously enhance the storage capacity and long-term stability of Bi2O3 as an electrode material for rechargeable aqueous aluminum-ion battery. It is found that a binder free integrated electrode of Bi2O3 on an exfoliated graphite current collector is better suited for improved electrochemical activity. When assembled with an Al metal anode, the integrated Bi2O3 electrode delivers a stable specific capacity of 103 mAhg−1 at a current rate of 1.5 Ag−1 over several charge/discharge cycles.