Specific performance of electrical double layer capacitors based on different separator materials in room temperature ionic liquid

Influence of the separator material characteristics on the performance of electrical double layer capacitors (EDLCs), based on the two identical ideally polarizable microporous titanium carbide‐derived carbon electrodes in room temperature ionic liquid (1‐ethyl‐3‐methylimidazolium tetrafluoroborate), has been tested by cyclic voltammetry, constant power and electrochemical impedance spectroscopy methods. Self‐made separator materials have been prepared from poly(vinylidene fluoride) solutions in N,N‐dimethylacetamide or N,N‐dimethylformamide and acetone mixture (8:2 mass ratio) by using the electrospinning method. Noticeable influence of the separator porosity and chemical composition on the limits of ideal polarizability, specific capacitance, equivalent series resistance, phase angle, specific energy and power of the EDLCs has been obtained and discussed.

► EDLC separator materials were prepared by electrospinning method.
► Electrospinning parameters are influencing separator material properties.
► Specific performance of EDLC depends noticeably on the separator material.
► Optimization of separators for ionic liquid based EDLCs
► The properties of the separators have to be carefully investigated and optimized.