Designing flexible electrochemical double-layer capacitors (EDLCs) that can operate efficiently at high and low temperatures remains a challenge specifi- cally related to packaging and electrolyte. The electrochemical performance of EDLCs is highly temperature dependent, and improved performance at high and low temperatures can be achieved if all components are designed for this purpose. Therefore, all solid-state symmetric EDLCs fabricated with solid-like electrolytes operating at high and low temperatures. A ionogel of poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) and N-butyl-N-methyl pyrroli- dinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) ionic liquid was used as the solid electrolyte and simultaneously the separator in these all-solid EDLCs. The synthesized solid ionogel with the highest ion mobility was made with a polymer to IL ratio of 1:4 in weight, which exhibits high ionic conductivity over a wide temperature range, from 0,229 mS/cm at 5°C up to 0,435 mS/cm at 70°C.