A PVA/LiCl/PEO interpenetrating composite electrolyte with a three-dimensional dual-network for all-solid-state flexible aluminum-air batteries

Aluminum-air batteries are promising electronic power sources because of their low cost and high energy density. However, traditional aluminum-air batteries are greatly restricted from being used in the field of flexible electronics due to the rigid battery structure, and the irreversible corrosion of the anode by the alkaline electrolyte, which greatly reduces the battery life. To address these issues, a three-dimensional dual-network interpenetrating structure PVA/LiCl/PEO composite gel polymer electrolyte (GPE) is proposed. The gel polymer electrolyte exhibits good flexibility and high ionic conductivity (σ= 6.51 × 10−3S cm−1) at room temperature. Meanwhile, benefiting from the high-performance GPE, an assembled aluminum-air coin cell shows a highest discharge voltage of 0.73 V and a peak power density (Pmax) of 3.31 mW cm−2. The Al specific capacity is as high as 735.2 mA h g−1. A flexible aluminum-air battery assembled using the GPE also performed stably in flat, bent, and folded states. This paper provides a cost-effective and feasible way to fabricate a composite gel polymer electrolyte with high performance for use in flexible aluminum-air batteries, suitable for a variety of energy-related devices. © The Royal Society of Chemistry 2021.