Elevated performance of binder-free Co₃O₄electrode for the supercapacitor applications

Abstract

In the present work, we have designed a symmetric supercapacitor (SS) device by synthesizing a pseudocapacitive binder-free cobalt oxide (Co3O4) thin film based electrode using reactive DC magnetron sputtering technique. The thin film electrodes were characterized by x-ray diffraction, Raman spectroscopy and x-ray photoelectron spectroscopy to reveal the crystallographic details, stoichiometry, and electronic configuration, respectively. Furthermore, Co3O4 thin film electrode is used for pseudocapacitor and electrochemically tested in 1M aqueous KOH electrolyte solution, in addition, a symmetric supercapacitor (SS) device was fabricated. It was found that the SS device exhibits tremendous electrochemical stability in terms of high capacitance and good cycling stability. The value of specific capacitance for Co3O4 thin film electrodes and the SS device was calculated to be 392 Fg−1 and 95 Fg−1, respectively, at a scan rate of 2 mAcm−2. The SS device exhibits high specific energy (29 W-hkg−1) along with comparable good specific power (4745 Wkg−1). In this work, the fabricated SS device demonstrates 91.40% cyclic and capacitance retention at 8 mAcm−2 beyond 10 000 cycles. The excellent electrochemical stability and capacitive performance of the SS device suggest that it would be an ideal and potential candidate for energy storage applications in the future.

Sonication-supported synthesis of cobalt oxide assembled on an N-MWCNT composite for electrochemical supercapacitors via three-electrode configuration

“…The specific capacitance of the synthesized composites was comparable to considerably increases in the stability of cobalt oxide-based composite electrodes reported previously (Table 1 ) 40 – 44 . Although it is challenging to arrange a clear-cut comparison of the electrode materials, the data in Table 1 were recorded using a range of parameters, such as the fabrication of electrodes, synthesis methods, capacitances observed at different current densities/scan rates, and cyclic stabilities 45 – 50 .…”

Composite Assembling of Oxide-Based Optically Transparent Electrodes for High-Performance Asymmetric Supercapacitors

“…According to the charge storage mechanism, there are two types of supercapacitors: one is an electric double layer capacitor which stores charge by accumulating charge that occurs at the interface of the electrode and the electrolyte and the other is a pseudocapacitor which works by adsorbing electrons and ions from the electrode and electrolyte interface. 13 Transparent supercapacitor's energy density can be defined as follows: E = 1/2 CV 2 , which can be obtained from both the capacitance (C) and operating voltage (V) of the supercapacitor. 21 Investigation of high theoretical energy storage materials with a varied operating potential window for transparent supercapacitors is significant for accomplishing high energy and power density.…”

“…Recently, the development of transparent devices has drawn extensive attention in the newly developing smart optoelectronics technology, which apparently brings technological innovation to daily life, including transparent displays, touch screens, and solar cells. , In this milieu, optical transparency and mechanical robustness are the key properties required to develop next-generation multifunctional devices, such as batteries, solar cells, supercapacitors, and displays. − Because of the perpetual increase in the demand for energy storage devices in handy electronics, steadfast research in the field of supercapacitor technology is required. Compared with batteries, supercapacitors have much higher power density, long cycling life, good capacitive performance, fast charging and discharging with outstanding reversibility, and low price, which make them potential candidates for use in broad applications such as in industrial power plants, built-in energy harvesting and storage systems, intermittent sensors, and portable electronics. − In general, transparent supercapacitors can be used as both the current collector for electron transportation and active electrode materials for energy storage. The performance of active electrode materials plays a vital role in the operation of supercapacitors.…”

Multiwalled Carbon Nanotube/PEDOT: PSS Coated on Pineapple Fiber Paper Based Flexible Electrode for Electrochemical Application

“…The CV curve implied that the capacitive performance of an electrode that can be determined from the area under the curve [24]. From the area under the CV curve, a specific capacitance (C p ) can be calculated using equation (2) [25,26], and it was found that the specific capacitance of 3% MWCNTs/PEDOT: PSS coated on fiber paper electrode equaled 0.011 Fg -1 . This indicated that charges could be stored at the surface of the fiber electrode (MWCNTs/PEDOT: PSS coated on fiber paper), allowing the use of the fiber electrode in electrochemical storage devices.…”

“…The CV curves of 3%MWCNTs/PEDOT: PSS at various scan rates are shown in Figure 4(b). The current density (i) can be calculated using equation 3 [15,25], which shows the relation between current density and specific capacitance. The current densities of the electrode at scan rates of 10, 20, and 50 mV s -1 were 0.35, 0.44, and 0.55 mAg -1 , respectively.…”