Review of Al2O3-based composite separators for lithium-ion battery

Abstract

Lithium-ion batteries (LIBs) have faced safety and performance challenges due to aluminum oxide (Al₂O₃)-based composite separators. This review aims to give you a comprehensive summary of recent advances in the design, fabrication, and application of Al₂O₃-modified separators. With their high surface activity, excellent hydrophilicity, and excellent thermal stability, Al₂O₃ ceramics are widely used as separators to improve thermal resistance, electrolyte wettability, and ionic conductivity, while effectively preventing lithium dendrite growth and improving mechanical strength, among other properties. A variety of composite architectures are discussed, including polymer/Al₂O₃ blends, ceramic-coated polyolefin membranes, and nanocellulose/Al₂O₃ hybrids, which have superior electrochemical properties, high porosity, and robust antishrinkage properties. Various mechanisms explain how Al₂O₃ contributes to improved separator performance, and the advantages of Al₂O₃-based systems in terms of safety, cycle stability, and rate performance are clearly demonstrated. Furthermore, the review outlines current challenges and provides perspectives on future research directions towards the practical implementation of Al₂O₃-based composite separators in high-performance LIBs of the future.