Cerium chloride-assisted subcritical water carbonization for fabrication of high-performance cathodes for lithium-ion capacitors

Abstract

Lithium-ion capacitors are considered highly promising as a hybrid-type energy storage system and are suitable for large-scale energy storage applications because of their superior power and energy density as well as prolonged cycle life. In this study, we developed an activated carbon (AC)-based electrode with excellent capacitive performance using salacca peel, a native Indonesian fruit, as the carbon precursor. The AC was synthesized via hydrothermal treatment of salacca peel with cerium (III) chloride (CeCl3) as the catalyst, followed by microwave-assisted chemical activation; the obtained sample was denoted as AC-S-CE. The addition of CeCl3 during the hydrothermal carbonization facilitated the formation of micropores in the AC; this resulted in a considerably greater surface area (1264.4 m(2) g(-1)) and a more defective graphitic structure than that of AC synthesized in the absence of CeCl3 (AC-S, 988.9 m(2) g(-1)) and of commercially available AC (742.8 m(2) g(-1)). In terms of being an LIC cathode, all the ACs exhibited a non-faradaic charge-discharge mechanism. AC-S-CE exhibited a higher capacitance of 90.6 F g(-1)- at 0.05 A g(-1) and improved cycling performance compared with those of AC-S and commercially available AC. [GRAPHICS] .