Gel polymer electrolytes with high ionic conductivity for the electrical double layer capacitors.

Symmetrical electrical double layer capacitors with ionic liquid potassium hydroxide (KOH)-based poly(acrylic acid) gel polymer electrolytes and activated charcoal electrodes were constructed and characterised. The optimised composition of gel polymer electrolytes exhibits high room temperature ionic conductivity of 0.46 S cm−1 with good mechanical and dimensional stability, which is suitable for their application as electrolyte in electrical double layer capacitors. Analysis shows that the maximum value of capacitance was 0.343 F cm−2, and this value corresponds to an energy density equal to 0.111 J cm−2. Electrical double layer capacitor exhibits large capacitance and high energy density. The results indicate that the gel polymer electrolyte used in our study is promising and is suitable as a solid electrolyte for high-performance all-solid-state electrochemical devices. [ABSTRACT FROM AUTHOR]