Fabrication of porous LaFe1−xCoxO3–MWCNT composites and their applications in supercapacitors

Abstract

This study synthesized LaFeO₃ perovskite oxide with different cobalt doping ratios using the sol–gel method, followed by in situ hydrothermal treatment. The optimized LaFe_0.8Co_0.2O₃ perovskite was then composited with linear multi-walled carbon nanotubes to investigate the structure, morphology, and electrochemical behavior of the composite material. In the composite material, linear MWCNTs were encapsulated into LaFe_0.8Co_0.2O₃, and the content of MWCNTs had a significant impact on the performance of the composite material. When the ratio of LaFe_0.8Co_0.2O₃ to MWCNTs reached 1 : 3, the electrochemical performance of the LaFe_0.8Co_0.2O₃–MWCNT sample was optimal. Additionally, LaFe_0.8Co_0.2O₃–MWCNTs-3 exhibited a high specific capacitance of 429.7 F g⁻¹ at a current density of 1.0 A g⁻¹, and the capacitance retention remained at 83.5% after 5000 cycles at a current density of 8.0 A g⁻¹. In a symmetric electrode configuration, a specific capacitance of 151.6 F g⁻¹ was achieved at the same current density, with a maximum energy density of 7.345 W h kg⁻¹.