A comprehensive review of alumina as an effective filler for enhanced electrochemical properties of solid polymer electrolytes

The need for alternative green energy to fossil fuels has increased research interest in creating energy storage technologies. One of the important components of an energy storage device is electrolytes. Previously, the use of liquid electrolytes (LEs) was dominant; nevertheless, LEs were reported to be flammable. Recently, attempts have been made to switch out the LEs for solid polymer electrolytes (SPE). SPE has a variety of merits; however, their limited ionic conductivity and high operating temperatures impede their development into practical application. Thus, fillers such as alumina (Al2O3) as an additive are introduced to enhance their performance. Recent progress in the use of Al2O3 has shown promising advancements in enhancing the electrochemical performance of SPEs while the future direction includes examining the cost-effectiveness of Al2O3-filled SPEs for large-scale applications, thereby paving the way for their integration into commercial energy storage technologies. This article provides a discussion on the effect of Al2O3 on the conductivity, and electrochemical stability of SPEs. Additionally, the review discusses the impact of various factors such as functionalization on the overall performance of SPEs-filled Al2O3. The review concluded by highlighting the potential applications, prospects, challenges, and recommendations for using Al2O3-filled SPEs in advanced energy storage devices.