Binder-less chemical grafting of SiO2 nanoparticles onto polyethylene separators for lithium-ion batteries

Abstract Silica nanoparticles were chemically grafted onto a porous polyethylene separator to improve the adhesion strength, thermal stability, and electrochemical performance of a polyolefin separator. A surface activation via UVO plasma treatment, followed by silane hybridization yielded a polymeric binder-free, thin coating of SiO 2 nanoparticles onto the separator. The chemical grafting provided a much stronger adhesive strength (> 2.5 N/cm), reduced thermal shrinkage ( 4 (LFP) cathode and SiO 2 -grafted separator showed an excellent rate capability (68 mAh/g at 5 C) and cycling performance (143 mAh/g after 200 cycles).