Thermally stable and green cellulose-based composites strengthened by styrene-co-acrylate latex for lithium-ion battery separators.

In this work, a thermally stable and eco-friendly separator composed of polyvinyl alcohol modified cellulose/styrene-co-acrylate composite (pCSA) was prepared via a facile and cost-effective phase inversion process. The results indicated that styrene-co-acrylate (SA) endowed the membrane with more network junctions, thereby, improving the film formation of membrane. Polyvinyl alcohol was used to further improve the electrolyte uptake of membrane, which was crucial for high electrical conductivity. The key merit of the as-prepared pCSA separator was embodied by its high porosity and wettability. Remarkable mechanical strength (58.7 MPa) and low thermal shrinkage stress (heating at 200 °C, 0.96 N) can be obtained by the fire resistant and tough SA in the composites. In addition, liquid electrolyte-soaked pCSA presented a high ionic conductivity of 1.34 mS cm at 30 °C and an excellent interfacial compatibility with electrode. Due to its simple preparation and superior performance, pCSA separators may open up a new field of application for lithium-ion battery separators where high safety, low cost and biocompatibility are required.