With the development of energy-storage devices, separator is encountered by several challenges including adequate safety, higher current density and superior stability. Tissue paper, composed of packed cellulose bers, possesses lower production cost, more easily accessibility, superior wettability and outstanding thermostability, thus being prospective as a substrate of high performance separator. To address structure collapse phenomenon occurred in conventional coating layer after long term electrolyte swelling, nano-SiO 2 hybrid crosslinked network was constructed on tissue paper through chemical reactions between polymer poly (vinylidene uoride-co-hexa uoropropylene) (PVDF-HFP) and hyperbranched polyethyleneimine (PEI) in this work. The in uences of crosslinking degree on physical properties and electrochemical performance were studied thoroughly. It can be found that when the crosslinking ratio of PVDF-HFP and PEI xed at 10:1, the crosslinked composite separator displays excellent electrolyte uptake and wettability, superior ionic conductivity, better interfacial compatibility as well as higher Li + transference number (0.56), thus offering battery with prominent rate capabilities.Besides, this crosslinked composite separator exhibits satisfying dimensional stability even treated at 250 o C, better ame retardancy, enhanced mechanical behavior, wider electrochemical window and outstanding cycle stability. Accordingly, tissue paper-based crosslinked composite separator can meet higher requirements put forward by high power lithium ion battery. HighlightsTissue paper was employed to fabricate lithium ion battery separator.Nano-SiO 2 hybrid crosslinked polymer electrolyte was constructed to modify tissue paper.The composite separator gave superior electrochemical performance and prominent rate capabilities.The designed coating layer was con rmed to increase mechanical strength, broaden electrochemical window and maintain cycle stability obviously.Excellent thermal stability and certain self-extinguishing were obtained for composite separator to afford security.

With the development of energy-storage devices, separator is encountered by several challenges including adequate safety, higher current density and superior stability. Tissue paper, composed of packed cellulose fibers, possesses lower production cost, more easily accessibility, superior wettability and outstanding thermostability, thus being prospective as a substrate of high performance separator. To address structure collapse phenomenon occurred in conventional coating layer after long term electrolyte swelling, nano-SiO2 hybrid crosslinked network was constructed on tissue paper through chemical reactions between polymer poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and hyperbranched polyethyleneimine (PEI) in this work. The influences of crosslinking degree on physical properties and electrochemical performance were studied thoroughly. It can be found that when the crosslinking ratio of PVDF-HFP and PEI fixed at 10:1, the crosslinked composite separator displays excellent electrolyte uptake and wettability, superior ionic conductivity, better interfacial compatibility as well as higher Li+ transference number (0.56), thus offering battery with prominent rate capabilities. Besides, this crosslinked composite separator exhibits satisfying dimensional stability even treated at 250 oC, better flame retardancy, enhanced mechanical behavior, wider electrochemical window and outstanding cycle stability. Accordingly, tissue paper-based crosslinked composite separator can meet higher requirements put forward by high power lithium ion battery.