Zirconia fiber membranes based on PVDF as high-safety separators for lithium-ion batteries using a papermaking method

Lithium-ion batteries have been receiving more and more attention because of the energy crisis. As an important subassembly of lithium-ion batteries, the separator greatly affects the safety of the batteries. Herein, we report for the first time, a novel method fabricated separator by mixing zirconia fibers with polyvinylidene fluoride (PVDF) via papermaking process. The separators possess abundant pores and uniform structure after the phase inversion process. The separator properties were systematically studied at different proportion of PVDF. We find that when the content of PVDF is 40%, the separator has high porosity (77.69%), high electrolyte uptake (523.3%), and excellent thermal stability (thermal shrinkage ratio is 0% at 500 °C). In addition, the rate capability, cycle performance, and ionic conductivity are also investigated. We anticipate that the papermaking method of zirconia fibers will provide a strategy to fabricate a promising separator for enhanced electrochemical performance and high safety of lithium-ion batteries.