An electrolyte based on paper, Al, polymer and salts – CAPSEL - has been successfully developed with ionic conductivity at room temperature of 10-2 S/cm without degradation up to 10000 cycles of cyclic voltammetry. The conductivity is maintained up to 50 ºC changing to 10-4 S/cm at 65 ºC. The developed electrolyte can be produced in two ways: 1- a mixture of anionic and cationic salts with Al and polymer all impregnated in a paper sheet; 2- a paper with Al ions, in one face is coupled a sheet of polymer with embedded cations and on the other face a sheet of polymer embedded with anions forming the catholyte and anolyte respectively. The later, when introduced in a graphene-electrolyte-graphene structure is less efficient in terms of capacity but show higher endurance for charge-discharge cycling. When applied between two graphene-based electrodes a capacitor with 5 mF is obtained after 5000 cycles of charge discharge at 1mA rate. The electrolyte and electrodes are all of facile manufacturing and low-cost materials while abundant and environmentally friendly.
