Separators in lithium ion batteries

As lithium-ion batteries are increasingly used as power sources in electric vehicles, the demand for high-performance lithium-ion batteries is growing. High-performance polymeric separators, which serve as an important component in lithium-ion batteries, are also attracting more and more attentions. Over the past few years, for improving the energy density, safety, and long-term use of lithium-ion batteries, researchers have used different methods to design and synthesize advanced membrane materials with high porosity, high affinity with electrolytes, thermal stability, electrochemical stability and other functional properties. The purpose of this chapter is to summarize the requirements of the separators, the types and preparation methods, and latest developments of advanced separators in lithium-ion batteries and have an outlook for the future development of the research about the separators.