Tissue paper-based composite separator using nano-SiO2 hybrid crosslinked polymer electrolyte as coating layer for lithium ion battery with superior security and cycle stability

In order to develop high power lithium ion batteries (LIBs), urgent requirements including adequate safety, higher current density and superior cyclic stability are proposed for separator. Tissue paper, composed of packed cellulose fibers, possesses lower production cost, easier accessibility, wettability together with outstanding thermostability, is thus a candidate be the substrate performance To address issue structural failure usually encountered by single polymer as binder during long term cycling, crosslinked was constructed on tissue paper adhere nano-SiO2 through chemical reactions between poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) hyperbranched polyethyleneimine (PEI) in this work. The effects crosslinking degree physical properties electrochemical were studied thoroughly. When feed ratio PVDF-HFP PEI fixed at 10:1, composite separator displays excellent electrolyte uptake wettability, ionic conductivity, better interfacial compatibility well Li+ transference number (0.56), offering battery prominent rate capabilities. Besides, exhibits satisfying dimensional even treated 250 °C, flame retardancy, enhanced mechanical behavior, wider window cycle stability. Accordingly, paper-based separators can meet put forward LIBs.