Ambient temperature rechargeable aluminum batteries and their key materials

Aluminum is a high energy carrier and an ideal electrode material for batteries. At present, the application of aluminum in rechargeable batteries are mainly high temperature molten salt batteries, all these rechargeable aluminum batteries use molten salt electrolyte, which must work at high temperature. The use of high temperature molten salt electrolyte limited the development of rechargeable aluminum batteries. Recently, researchers begin to use ambient temperature ionic liquids as electrolyte of rechargeable aluminum batteries, which can prevent the formation of oxide films on the aluminum surface as well as eliminate H₂ evolution. This new battery system working at mild condition, which adopts aluminum or aluminum intercalation compounds as electrodes and ionic liquids as electrolytes, has many advantages compared to conventional rechargeable batteries. This paper introduces related researches and applications of ambient temperature rechargeable aluminum batteries in recent years, including the optimizing of aluminum anode and inhibition of dendrite, the design of aluminum anode materials that can intercalate and release aluminum ion, the performance of polymer cathode materials and transition metal oxide cathode materials, the request of electrolytes, and advantages of ionic liquid used as electrolyte. Furthermore, possible existent problems and corresponding solutions are proposed.