A low-cost, environment-friendly lignin-polyvinyl alcohol nanofiber separator using a water-based method for safer and faster lithium-ion batteries

A lignin/polyvinyl alcohol (lignin/PVA) nanofiber membrane has been prepared as a separator for lithium-ion batteries (LIBs) using a simple, low-cost, environment-friendly, water-based method. Lignin is a widely abundant, naturally occurring biopolymer and polyvinyl alcohol (PVA) is a biocompatible polymer with good chemical and thermal stability. In this work, lignin and PVA were dissolved in water, and fibers were drawn from the solution to form a non-woven membrane. A highly porous interpenetrating network structure resulted that showed high electrolyte uptake, excellent compatibility, and superior wettability. The membrane also showed high thermal stability and flame retardant properties. Electrochemical performance revealed high rate capability with the lignin/PVA membrane that is attributed to its high ionic transport property. The as prepared lignin/PVA membrane, thus, can be considered as a separator for safer and faster LIBs with various different anodes.