EDLC Capacitance Optimization Using the Taguchi Technique

Abstract

Abstract -The Taguchi technique was applied in this work to maximize the capacitance of a supercapacitor. The key issue in applying the Taguchi technique is to identify and control the process factors that will lead to optimized capacitance of the supercapacitor. The reported method used in literature is the trial and error method (optimizing one factor at a time). DOE (Design of Experiments) allows multiple parameters to be evaluated with a limited number of experiments. With the use of the Taguchi methodology, in this paper, the number of required experiments was reduced from (3 3 ) = 27 experiments to only 9 experiments while at the same time producing a more robust product. The main materials used for the fabrication process are activated carbon (AC), which was used as the active material; carbon black (CB) which was used as the conducting agent; and PVDF (Polyvinylidene fluoride) polymer, which was used as binder agent. A total of nine capacitors were fabricated, and the following factors were varied: PVDF percentage, CB percentage and mixing time. This experiment was performed to find the dominant parameter affecting the capacitance. A 1 M (LiClO4) sample in an acetonitrile organic solution was used as an electrolyte, and a 13 mm diameter disc-shaped super-capacitors were fabricated. The cells capacitance was found to range from 24.91 to 51.23 mF with the different process factors. The properties of the fabricated cells were measured using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and charge-discharge measurements. Auto lab (PGSTAT302N) was used to perform the measurements. The results indicated that the binder percentage and mixing time have a significant effect on the capacitance. A final confirmation cell was fabricated using the optimised factors