In an effort to develop Al$^{3+}$ ion-based rechargeable electrochemical cells, there is massive exploration of appropriate electrode materials in contemporary times. Aluminium is a natural choice due to its high abundance, low cost and easy processing. Herein, the working of rechargeable aqueous aluminium-ion batteries which comprise graphite from pencil sketch as the cathode, TiO$_2$ as the anode and an Al$^{3+}$ ion conducting aqueous electrolyte is demonstrated for the first time. The aluminium-ion cell delivers a discharge voltage of 1.5 V and stable specific capacities of 25 mAh g$^1{−1}$ over 1000 cycles. This proof of concept emphasizes on the possibility of achieving sustainable, easy to assemble and low-cost rechargeable batteries.

This report illustrates an investigation on the electrochemical stability of bismuth oxychloride (BiOCl) for rechargeable aluminium–metal battery for the first time. It is shown that Al$^{3+}$ ion could be stored in bismuth oxychloride in aqueous electrolyte. A stable discharge capacity of 145 mAh g$^{-1}$ was achieved over 200 cycles at a current rate of 2.5 A g$^{-1}$. It is found that capacity decline was a major concern. However, a simple and innovative strategy was adopted to dramatically improve the electrochemical stability by synthesizing a binder-free BiOCl electrode on a thermally exfoliated graphite current collector. The use of such current collector is also shown for the first time. The facile method of processing the exfoliated graphite is also discussed.