A Procedure for Evaluating the Capacity Associated with Battery-Type Electrode and Supercapacitor-Type One in Composite Electrodes

Abstract

This paper provides a procedure for evaluating the capacity or charge of composites consisting of battery-type electrode and supercapacitor-type one. The composites, which are binder-free flexible materials, consist of cobalt oxide (CoO x) electrodeposited on the fibers of a carbon cloth (CC). The deposited CoO x shows battery-type response. The CC substrate shows supercapacitor-type one. The procedure here reported is based on galvanostatic charge/discharge measurements. It is easier, less laborious and faster than the procedure based on the kinetic study by cyclic voltammetry. The two procedures are compared. The dependences of the specific capacities as functions of the current density and voltage scan rate show similar patterns. The contribution of the two types of materials to the specific capacity of the complete electrode is discussed. The electrodedeposited CoO x contributes increasing the specific capacity of the composites at low current densities. The CC substrate dominates the specific capacity of the composites at high current densities.

Novel bouquet-like cobalt phosphate as an ultrahigh-rate and durable battery-type cathode material for hybrid supercapacitors

“…acteristics of the Co 3 (HPO 4 ) 2 (OH) 2 electrode[17]. The prolonged discharge time of the GCD profiles illustrates the high specific capacity of the Co 3 (HPO 4 ) 2 (OH) 2 electrode.…”

Transition metal dichalcogenide nanostructured electrodes without calcination for aqueous asymmetric supercapacitors

“…It is worth mentioning that CC is an inexpensive and good flexible textile material and was selected as a substrate for the deposition of active materials. 62 However, the bare CC exhibited relatively poor capacitance (1-2 F g À1 ) as compared to the remaining carboneous materials. 51 This statement is well consistent with the measured poor electrochemical behavior of the bare CC in this study.…”

High-performance supercabatteries using graphite@diamond nano-needle capacitor electrodes and redox electrolytes

“…As mentioned, the ( pseudo)capacitance of a capacitor electrode can be 100-1000 times enhanced once the redox electrolyte is applied. 19,[35][36][37] Therefore, the capacitance of graphite@ diamond nano-needles in the redox-active electrolyte (here 0.05 M Fe(CN) 6 3−/4− + 1 M Na 2 SO 4 ) was measured using cyclic voltammetry and the GCD technique. All CVs (Fig.…”

“…4a) and GCD curves (Fig. 4b) Then, a solution of 1 M Na 2 SO 4 containing 0.05 M Fe(CN) 6 3−/4− was used as the electrolyte. The performance of this PC device was studied by applying a cell voltage of 1 V. In the related CVs (Fig.…”

“…4 Although these processes occur slowly and in bulk electrode materials for batteries, a PC is still called in some cases a battery-like capacitor or a supercabattery. [5][6][7][8] To construct a supercabattery, namely a supercapacitor with a large and stable capacitance (C) and high power (P) and energy (E) densities, one needs to consider carefully the employed capacitor electrode as well as the applied electrolyte.…”