Flexible Aluminum-Air Battery Based on Ionic Liquid-Gel Polymer Electrolyte

Abstract

There is an urgent demand to develop high-performance flexible batteries for a wide range of contemporary emerging fields, including flexible electronics, wearable sensors, and implantable medical devices. However, the inherent safety and stability issues of traditional organic liquid-based electrolytes make their application in flexible batteries unsatisfactory. Therefore, exploring gel electrolytes with superior ionic conductivity and safety is considered to be the key to the development of flexible batteries. In this paper, two types of high-quality ionic liquid-based gel polymer electrolyte membranes (PVDF-ILs) are created by a conventional solution-casting method, which are further integrated into flexible aluminum-air batteries to guide the interface and process research, and the related discharge properties of two ionic liquid-based electrolyte membrane (PVDF-[C₄mpyr]Cl, PVDF-[BMIM]Cl) in different bending states are discussed. The results show that PVDF-ILs have a rich pore structure and interwoven skeleton network, leading to relatively high ionic conductivity (2.97 × 10^–3 S cm^–1). Moreover, two types of batteries can meet the needs of flexibility, although there is a slight loss of power density under various bending conditions. In general, a PVDF-[C₄mpyr]Cl-based flexible aluminum-air battery is suitable for the working conditions of high power and low bending angle, while the PVDF-[BMIM]Cl-based flexible aluminum-air battery is favored for microwatt low-power devices with high flexibility requirements.