The Application of Nanomaterials in Lithium-ion Battery Separators

Abstract

With the rapid development of electric vehicles and smart grids, lithium-ion batteries (LIBs), as key energy storage devices, face the demand for improved safety. The traditional polyolefin separator has problems like insufficient thermal stability and poor interfacial compatibility, which have become a technical bottleneck for the development of high-energy-density batteries. This study aims to enhance the thermal stability and electrochemical performance of LIBs separators through nanomaterial modification strategies, providing solutions for developing next-generation high-safety batteries. This paper first introduces the basic functional requirements of LIBs separators and the performance limitations of traditional materials, focusing on the key issues of the shrinking behavior of PE/PP separators at high temperatures and their electrolyte wettability. Then, it explores three types of nano-modification methods: PVDF-based materials improving interfacial properties through polar groups, ceramic nano-coatings significantly enhancing thermal stability, and metal nanomaterials optimizing ion transport kinetics (with a 4C capacity retention rate of 84.3%). Finally, it analyzes the relationship between nanostructure parameters and the macro-properties of separators and reveals the mechanism of uniform Li⁺ deposition through synchronous radiation techniques. This research provides theoretical guidance for the design of high-safety LIBs separators. It has essential reference significance for the development of new energy storage devices such as solid-state batteries.