All-solid-state supercapacitors (SCs) were fabricated using a polyvinylidene fluoride (PVDF)/lithium trifluoromethanesulfonate (LiTFS) membrane as the separator and poly(ethylene oxide) (PEO)/lithium perchlorate (LiClO4) as the polymer electrolyte in the porous carbon electrodes. Two types of mediators, NaI/I2 and K3Fe(CN) 6/K4Fe(CN)6, were added into the PEO/LiClO 4 polymer electrolyte that was used to fabricate the electrodes. The voltage window in which the SCs operated was 2.5-3 V. The results of electrochemical measurements, including cyclic voltammetry and galvanostatic charge/discharge, indicated that NaI/I2-containing and K 3Fe(CN)6/K4Fe(CN)6-containing SCs yielded high specific capacitances of 209.0 and 138.8 F g-1, respectively. In addition to high specific capacitances for the two mediator-containing SCs, both SCs delivered high specific energies (49.1 Wh kg-1 at 1.6 kW kg-1 for the NaI/I2-containing SC and 33.6 Wh kg-1 at 1.3 kW kg-1 for the K 3Fe(CN)6/K4Fe(CN)6-containing SC) due to the wide voltage window and fast redox reactions between mediators.
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Energy Engineering and Power Technology
- Renewable Energy, Sustainability and the Environment
- Physical and Theoretical Chemistry