Homogeneous Titanium Hydroxide Yields Hydroxyl Decorated Nanofiber Separator with Improved Electrolyte Uptake and Device Capacitance

Abstract

Good wettability of separators in batteries and capacitors is crucial for performance. Titanium hydroxide (Ti(OH)x) has been shown to greatly improve the wettability of polyvinylidene fluoride (PVDF) nanofibers (NFs). In this work, PVDF/Ti(OH)x NFs were evaluated for their potential use as separators. Results show that PVDF NFs incorporated with Ti(OH)x have improved electrolyte uptake (EU) between 550 and 1200 EU% compared to untreated PVDF with less than 100 EU%. Significant improvements in capacitance are seen from capacitors utilizing PVDF/Ti(OH)x NF separators with the best performing PVDF/Ti(OH)x NF at 15 wt% Ti(OH)x with 446.8 mF/cm2 compared to untreated PVDF NF separator with 262.7 mF/cm2.