Core–shell structure γ-MnO2-PANI carbon fiber paper-based flexible electrode material for high-performance supercapacitors

Abstract

Good conductivity is the key to ensuring high electrochemical performance, and the uniformity of the active material directly affects the electrical conductivity. This paper proposes a novel modified stepwise in situ polymerization method to prepare composite materials, and then uses the K/S value method to characterize the uniformity of polyaniline distribution. Specifically, the study presents a papermaking wet-lay technique to prepare a carbon fiber paper substrate (CP) that is light-weight, flexible, and foldable while also having low internal resistance and high porosity. The γ-MnO2 is wrapped with PANI to form a core–shell structure, and a modified stepwise in situ polymerization method is adopted to deposit the core–shell structure uniformly on the CP substrate by physical adsorption. This process yields a flexible electrode material for supercapacitors, called γ-MnO2-PANI-CP electrode. Results show that the γ-MnO2-PANI-CP electrode has a high specific capacitance of 642.5Fg−1 at a current density of 1Ag−1, and also has a high energy density of 114.2Whkg−1 at a power density of 798.6Wkg−1. In addition, the electrode retains 81.3% of the initial capacitance after 5000 cycles, demonstrating high cycling performance.