Fast and Economical Method to Produce Thin-Film Electrodes for Supercapacitors

July 08, 2019 by Scott McMahan

Researchers from the University of Arkansas at Little Rock have developed a new and inexpensive method to fabricate thin-film electrode materials for supercapacitors that deliver higher power at a lower cost. (See the image above of the schematic representation of electrochemical deposition of PPy films using pyrrole and CoN4 complex. The films were deposited on GCE. -- image courtesy of Scientific Reports cited below).

Supercapacitors have the advantages of charging quickly and retaining their storage capacity for thousands of recharging cycles, and they are used in a variety of applications such as high-powered lasers, wireless telecommunications, and electric vehicles' regenerative braking systems.

"In industrial applications, we can build the thin film electrode for high-performance supercapacitors in less than one hour via a simple technique using these low-cost materials, which can significantly speed the process and lower the cost of synthesis," said Dr. Anindya Ghosh, professor of chemistry at UA Little Rock, who led the research team.

The team, which included students and researchers from UA Little Rock and the University of Arkansas, recently published their findings in Scientific Reports, a publication in the Nature family of journals. Bijay Chhetri, a UA Little Rock biology doctoral student, and Dr. Charlette Parnell, a forensic chemist at Arkansas State Crime Laboratory, were the lead authors.

The research included the development of a novel and simple method to design thin-films using a cobalt metal complex and a conducting polymer for use in supercapacitors. According to the researchers, this material costs less than many competing technologies, making it a possible game-changer for a broad range of real-world applications.

They prepared a Co(III) complex and polypyrrole (PPy) composite thin films (CoN4-PPy) that they electrochemically deposited on a glassy carbon working electrode. Cyclic voltammetry studies showed the superior performance of CoN4-PPy in charge storage in acidic electrolyte compared to alkaline and organic solutions.

From their observations, they concluded that the novel thin films made from Co(III) metal complex and PPy can store large amounts of energy and maintain high stability over many cycles, giving them excellent potential for use in supercapacitor devices.

"Our approach to fabricate low-cost thin film electrode materials offers a feasible solution to fabricate supercapacitor devices with high power density and reduced production cost in real-world applications," Chhetri said.

The researchers believe their work can aid the scientific community beyond their use in supercapacitor electrodes.

"Our research embraces a novel method for improving the ongoing developments in this exciting field," Parnell said. "With this supercapacitor material, we are helping pave the way toward using inexpensive catalysts and electrode materials for a more economical and benign approach. These materials provide a platform for further developing improved supercapacitors that will enhance modern technology for energy storage in automotive and railway transportation and overall power grid efficiency."

Financial support for the research came from the Center for Advanced Surface Engineering under the National Science Foundation Grant No. IIA-1457888 and the Arkansas EPSCoR Program, ASSET III.

Reference Material

Parnell, C. M., Chhetri, B. P., Mitchell, T. B., Wantanabe, F., et al.  Simultaneous Electrochemical Deposition of Cobalt Complex and Poly(pyrrole) Thin Films for Supercapacitor Electrodes, Scientific Reports, published April 4, 2019, volume 9, Article number: 5650 (2019).