Poly(Vinylidene Difluoride) Soft Dendritic Colloids as Li-Ion Battery Separators

As an alternative to Li-ion battery (LIB) microporous membrane separators that are typically comprised of polyolefins, other materials and separator morphologies may yield increased cell performance. Here, we present a new class LIB comprising poly(vinylidene difluoride) (PVDF)-based highly branched, colloidal polymer particulates, called soft dendritic colloids, produced by shear-driven precipitation within turbulent nonsolvent flow followed filtration. We show the morphology resulting PVDF particulates be varied from fibrous colloids thin porous sheet-like particles. The use leads low thermal shrinkage (5% at 90 °C) high tensile strength (<0.7% offset 1000 psi), while porosity (up 80%) particle surface area responsible for conductivity (1.2 mS cm ?1 ) electrolyte uptake (325%), good capacity (112 mAh g in Li/LiCoO 2 cell) with <10% loss after 50 cycles. Because filtration is facile versatile process make polymeric separators, promising candidates as next-generation batteries.