Binder-free fabricated CuFeS2 electrodes for supercapacitor applications

Abstract Copper iron sulfide (CFS) (chalcopyrite) thin-film electrodes have been synthesized for energy storage applications using the SILAR method without the use of a binder. The film’s structural as well as the morphological and electrochemical characteristics were studied to check the effect of varying deposition cycles. The x-ray diffraction (XRD) test reveals a crystalline tetragonal CuFeS2 (chalcopyrite) with a decreasing peak as the deposition cycle progresses. The micrographs of the films reveal a spherical but fleecy-like shape with particle aggregation at higher deposition cycles. The bandgap increased slightly towards higher cycles and is in the range of 1.15 to 1.22 eV. The CFS electrodes were evaluated in a three-electrode arrangement for supercapacitive application in a 2.0 M KOH electrolyte. The CFS electrodes function admirably. The greatest specific capacitance recorded was 537 F g−1 at 10 mV s−1 with capacitance retention of 93.5%. This is for CFS electrode deposited at 10 cycles; hence it has the greatest performance. This paper describes a simple, inexpensive, and repeatable method for fabricating electrodes for supercapacitors.