Lithium ion batteries have dominated the field of energy storage for portal electronics during the past twenty years, and now it is ambitious to power electric vehicles. However, drawbacks of limited power density and cycle life time as well as cost and safety concerns lead to limitations for the emerging large-scale stationary energy storage application. Therefore, researchers all over the world have been dedicated to find alternative next-generation energy storage technologies. Rechargeable Al-ion battery is emerging as one of the most promising sustainable candidates for the usage of large-scale energy storage because of its low-cost, high charge/discharge rate capability and extremely long cycling life. However, currently most of the Al-ion battery has been developed by using of liquid electrolyte, such as ionic liquid, urea and molten salt electrolyte, which has the risk of electrolyte leakaging. Electrolyte evaporation also occurs when batteries undergo extremely long cycling charge/discharge process. While making all-solid-state Al-ion battery is able to effectively solve the leakaging problem, but there are few reports on this topic. What is more, the all-solid-state Al-ion battery also has higher energy density due to device structure design of using no separators and bulky packaging. In this paper, we have developed a new kind of solid Al-ion electrolyte by using crown ether as both functional additive and coordination group and polyethyleneglycols (PEO) as basement through a solution casting method. Experiment tests indicates that the crown ether could not only yield a good stability and compatibility of Al ions with PEO but also reduce the crystallinity of composite electrolyte, which is helpful for achieving high ion conductivity. The obtained AF solid-state electrolyte has a high ion-conductivity (5.5×10^-6 S/cm at room temperature, 1.86×10^-3 S/cm at 100℃), broad electrochemical potential window (0~3 V) and strong mechanical property. This work provides applicable high-performance polymer electrolyte and paves the way to develop the full all-solid-state Al-ion batteries.

Key words: Al-ion battery, solid polymer electrolyte (SPE), solution casting method, crown