Synthesis of polyaniline/nickel oxide/sulfonated graphene ternary composite for all-solid-state asymmetric supercapacitor

Abstract The preparation of a structurally optimized electrode material plays an important role in the energy application of the supercapacitor. Here, we report that an electrode assembly composed of a ternary material has a unique microstructure and excellent electrochemical performance. Our supercapacitor electrodes consist of sulfonated graphene (SGO) as a substrate, a well-dispersed metal oxide (NiO) and a polymer (PANI) that provides more surface area. Hydrothermal and chemical oxidative polymerization methods are used to formulate the core-shell structure composed of the aforementioned three materials, and the synergistic effect improves the performance of supercapacitors, including high specific capacitance and excellent cycle stability. The PANI/NiO/SGO (2:1) ternary composite has a high specific capacitance of 1350 F g−1 at a current density of 1 A g−1 and a capacity retention rate of 92.23% after 5000 cycles. The prepared all-solid states asymmetric supercapacitor PANI/NiO/SGO//Active Carbon (AC) has a high specific capacity of 308.8 F g−1, high energy density (109.8 Wh kg−1), high power density (0.8 kW kg−1) and stable cycle life (capacitor retention rate is 91.15% after 10,000 cycles), while a green LED indicator is illuminated.