Sulfonated poly(ether ether ketone) membranes for electric double layer capacitors

Sulfonated poly(ether ether ketone) (S-PEEK) with different degree of sulfonation (DS) has been prepared and evaluated as a proton conducting membrane for electric double layer capacitor (EDLC). The polymer electrolytes prepared with S-PEEK membrane exhibited ionic conductivities about 1.2 × 10−3–4.5 × 10−3 S cm−1 at room temperature, which depended on both soaking solvent and degree of sulfonation. The quasi-solid-state EDLCs consisted of activated carbon electrodes and S-PEEK membrane were assembled, and their electrochemical characteristics were studied by cyclic voltammetry and charge–discharge cycle tests. The effect of DS on the electrochemical performances of EDLCs has been investigated.