摘要/Abstract
铝离子电池因其材料成本低、大倍率性能优异和循环寿命超长等优势，而被认为在大规模静态储能应用中具有广阔前景.目前的铝离子电池大部分采用离子液体、尿素和熔融盐等液态电解液，其在实际工程化应用当中存在电解液渗漏的风险.相对而言，全固态电池则可以避免电解液渗漏的问题，还具有因去除隔膜和简化封装所带来的电池整体能量密度提升的优点.但是，目前领域内少有关于全固态铝离子电池的研究.基于此，采用溶液浇筑法，以冠醚作为添加剂和配位基团、以聚乙二醇（PEO）作为基底，制备出无定型结构的聚合物固态铝离子电解质.其中，冠醚不仅作为配位基团与铝离子进行配位提高铝离子的稳定性，而且作为相容性高的添加剂降低聚合物结晶度，从而提高固态电解质的离子电导率.测试表明，制备出的18-6/PEO/Al（CF3SO3）3体系聚合物固态铝离子电解质是非晶态为主的晶态与非晶态共存的薄膜，且具备很高的离子电导率（室温，5.5×10-6 S/cm；100℃高温，1.86×10-3 S/cm）和较宽的电化学稳定窗口（0~3 V），这为全固态铝离子电池的研发奠定了基础.
关键词: 铝离子电池, 聚合物电解质, 溶液浇筑法, 冠醚
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
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