Principles and Requirements of Battery Membranes: Ensuring Efficiency and Safety in Energy Storage

Abstract

This critical review highlights the latest improvements and special features regarding the membrane separators available for lead-acid, alkaline, metal-metal, metal-gas, and metal-ion batteries such as lithium-ion. In the recent years, there has been a surge in the intensive work aimed at developing innovative separators for rechargeable lithium-ion batteries, for example, electric vehicles (EVs), portable electronics and for energy storage in power grid. The separator finds itself in a very important place as it provides physical separation between two electrodes. It also acts as an electrical insulator. This separator is known as an electrolyte gateway which helps the movement of ions during charge/discharge cycles. This review addresses the requirements for battery separators and explains the structure and properties of various types of membrane separators; there are several types of membranes such as microporous membranes, modified microporous membranes, nonwoven mats, composite membranes and electrolyte membranes. Similarly, each type of separator has inherent advantages and disadvantages which in turn directly affects the performance of batteries. This review article systematically deals with the structures and working principle of separators, properties and main requirements and their characterization method of separators, generation, improvements, and function assessments of these separators. Furthermore, this study also enlightens the emerging research path and future prospects.