In-situ growth of biomass-derived carbon coating on LaMnO3 nanofibers: synergistic interface interaction for enhanced energy storage performance

In recent years, a variety of materials have been employed to improve the electrochemical performance of perovskite-type oxides, thereby achieving high energy and power densities simultaneously. In this study, a series of carbon-coated LaMnO 3 nanofiber (LMO@C) composites were synthesized via the in-situ hydrothermal generation of various biomass-derived porous carbon, denoted as LMO@C-g (glucose), LMO@C-su (sucrose), and LMO@C-st (starch). After heat-treatment in Argon, the LMO@C composites were subjected to different physicochemical characterizations to investigate the impacts of different carbon sources on the variations in their microstructure and element valence. The ordered polymeric structure of starch provides LMO@C-st with three significant advantages, suggesting its optimal energy storage performance. Additionally, based on the electrochemical results, LMO@C-st is the most optimum sample due to its excellent electrochemical behavior with maximum C s (798.7F g −1 ), superior rate capability (68%), and the best coulombic efficiency (95%). The first-principles calculations indicate that the improvement of charge storage capacity and transport kinetics arise from the strong interface interaction between the covalently bonded carbon and LMO. Furthermore, a symmetric supercapacitor (LMO@C-st||LMO@C-st) fabricated in this work reveals an outstanding specific capacitance, superior energy density and excellent cycling stability, demonstrating an effective new approach to the development of energy storage materials.