A Novel Aluminum‐Ion Battery: Al/AlCl 3 ‐[EMIm]Cl/Ni 3 S 2 @Graphene

Due to an ever‐increasing demand for electronic devices, rechargeable batteries are attractive for energy storage systems. A novel rechargeable aluminum‐ion battery based on Al 3+ intercalation and deintercalation is fabricated with Ni 3 S 2 /graphene microflakes composite as cathode material and high‐purity Al foil as anode. This kind of aluminum‐ion battery comprises of an electrolyte containing AlCl 3 in an ionic liquid of 1‐ethyl‐3‐methylimidazolium chloride ([EMIm]Cl). Galvanostatic charge/discharge measurements have been performed in a voltage range of 0.1–2.0 V versus Al/AlCl 4 − . An initial discharge specific capacity of 350 mA h g −1 at a current density of 100 mA g −1 is achieved, and the discharge capacity remains over 60 mA h g −1 and coulombic efficiency of 99% after 100 cycles. Typically, for the current density at 200 mA g −1 , the initial charge and discharge capacities are 300 and 235 mA h g −1 , respectively. More importantly, it should be emphasized that the battery has a high discharge voltage plateau (≈1.0 V vs Al/AlCl 4 − ). These meaningful results represent a significant step forward in the development of aluminum‐ion batteries.