Cr-doped ceria for solid-state symmetric supercapacitor using gel-electrolyte
摘要
Cerium oxide (CeO₂), a rare earth oxide with redox properties, has garnered significant attention for its potential in pseudocapacitors due to its ability to undergo reversible redox reactions. However, the inherent limitations in its electrochemical activity, such as poor conductivity and limited ion diffusion, hinder its overall performance. To address these limitations, this study investigates the effect of chromium (Cr) doping in CeO₂, aiming to enhance its electrochemical properties for use in pseudocapacitors. The research presents the hydrothermal synthesis of Cr-doped CeO₂, which is coated on nickel foam to construct a high-performance all-solid-state symmetric pseudocapacitor. The device demonstrates an areal capacitance of 4.46 mF cm⁻2 at a current density of 0.8 mA cm⁻2, showing remarkable stability and low capacitance decay of only 20% after 10,000 charge–discharge cycles. The performance is further evaluated across varying current densities, from 0.8 to 2.5 mA cm⁻2, before returning to the original 0.8 mA cm⁻2 current density, indicating good cycling stability. Incorporating Cr in CeO₂ significantly improves the material’s electrochemical behavior by enhancing charge transfer kinetics and promoting structural stability, which ultimately contributes to the superior performance of the pseudocapacitor. This work highlights the potential of Cr-doped CeO₂ as a viable material for high-performance energy storage devices and paves the way for further exploration of doping strategies to optimize the electrochemical properties of CeO₂-based materials.