Composite of polyvinylidene fluoride-cellulose acetate with Al(OH)3 as a separator for high-performance lithium ion battery

As an important component of the lithium ion batteries, the separator has attracted much attention by researchers. In this paper, a polymer electrolyte separator based on the blended polymer of polyvinylidene fluoride and cellulose acetate was obtained via non-solvent induced phase separation (NIPS), meanwhile, the Al(OH)3 particles was used as the addition doping into the blended polymer matrix. The structure, for example, pore size, porosity and the crystallization of the resulting separators were characterized. The thermal stability, ionic conductivity and electrochemical performance were also investigated. The results indicated that the PVDF-CA/Al(OH)3 separator presented high porosity (68.6%), high electrolyte uptake (403.9%), especially superior thermal stability (thermal shrinkage ratio was 4.6% at 160 °C) and excellent ionic conductivity (2.85 mS cm−1). In addition, the rate capability (128.28 mA h g−1 at 8 C) and cycle performance (151.97 mA h g−1 after 100 cycles at 1 C) were also superior to those of the commercial polypropylene separator, demonstrating that the PVDF-CA/Al(OH)3 separator can be a promising separator for the high-safety and high-rate dischargeable lithium ion battery.