Gel hybrid copolymer of organic palygorskite and methyl methacrylate electrolyte coated onto Celgard 2325 applied in lithium ion batteries

ABSTRACT Separator is a critical component in the rechargeable lithium‐ion battery. The continuous improvement in the performance of the separator is usually focused on reducing its thermal shrinkage and improving ionic conductivity. A new composite separator poly(organic Pal‐ co ‐methyl methacrylate) [p(OPal‐MMA)@CPM] was developed by coating the hybrid polymer [p(OPal‐MMA)] of organic palygorskite and MMA onto both sides of a Celgard 2325 [polypropylene (PP)/polyethylene /PP, CPM] in this research. The ionic conductivity and liquid electrolyte uptake of the p(OPal‐MMA)@CPM were dramatically improved compared to CPM. The thermal shrinkage percentage of the composite separators was significant decreased compared to the pure CPM. The Li + transference number of Li/p(OPal‐MMA)@CPM/Li cell (0.893) was higher than that of Li/CPM/Li cell (0.483). Lithium iron phosphate/p(OPal‐MMA)@CPM/Li cell showed high capacity on charge–discharge cycles compared with poly(MMA) and CPM. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47970.