What about electrochemical behaviors for aurivillius-phase bismuth tungstate? Capacitive or pseudocapacitive

Abstract

Researchers mainly explore the mechanism of pseudocapacitance through studying electrode materials with Faraday pseudocapacitive behavior. Here, we found that Bi₂WO₆, a typical Aurivillius phase material with pseudo-perovskite structure, showed nearly ideal pseudocapacitive behavior. The cyclic voltammetry curve is approximately rectangular in shape, with no redox peaks, which is similar to that of carbon materials. And the shape of the galvanostatic charge–discharge curve is close to an isosceles triangle. In addition, the kinetic analysis demonstrated that the electrochemical process of the A-Bi₂WO₆ electrode is dominated by surface processes, not diffusion. The A-Bi₂WO₆ electrode material presents a great volumetric specific capacitance of 466.5 F cm⁻³ at 0.5 A g⁻¹. These electrochemical properties confirm that the Bi₂WO₆ material can serve as an ideal support material to explore pseudocapacitive energy storage. This work also provides guidance for the development of new pseudocapacitive materials.