High-performance electrospun membrane for lithium-ion batteries

Lithium-ion battery separator is one of the core battery components, owing to its assistance in ion migration and prohibiting electron transport inside the battery. Traditional separators made of polyolefin do not provide sufficient wettability to provide high energy density required for applications in high-end field. Although electrospun lithium ionized poly(ethylene-co-vinyl alcohol) (EVO-Li) membranes were considered earlier, their mechanical properties still appear to be inferior. In this work, the surface modification of EVO-Li membranes by poly-dopamine (PDA) with benzene structure and excellent adhesion ability to enhance their mechanical properties is reported. PDA was found to react with EVO-Li and form the C-N-O bonds, which further improved the ultimate tensile strength of the membrane. Simultaneously, its uptake property and thermostability were also improved. [Display omitted] •Preparation of lithium battery membrane by electrospinning.•Coordination Li+ was formed by dopamine and EVO-Li.•After coating with poly-dopamine, thermostability of membrane was promoted.•The mechanism of enhancing mechanical properties was proposed.