Application of cathodic composite electrodeposition for binder-free novel NF@Ni/rGO-MnO2 electrode with Ni/rgo interlayer for high-performance supercapacitor

In this study, a high-performance binder-free NF@Ni/rGO-MnO2 electrode for supercapacitors was fabricated using a multi-step electrodeposition process. The Ni/rGO interlayer, with a cumulus/cauliflower-like structure, was cathodic composite electrodeposited onto NF, followed by anodic deposition of MnO2 with a three-dimensional granular morphology. This composite structure outperformed NF@MnO2, where MnO2 was directly deposited onto the NF. Under optimal conditions, the NF@Ni/rGO-MnO2 electrode achieved a specific capacitance of 890.4 F<middle dot>g(-1) at 1 mA<middle dot>cm(-2) and retained 105.7% capacitance after 10,000 cycles, compared to 851.5 F<middle dot>g(-1) and 65.6% retention for NF@MnO2 after 2000 cycles. These improvements are attributed to reduced series resistance, enhanced conductivity, and increased active surface area of NF@Ni/rGO-MnO2 electrode from the multi-step deposition process. The mechanism behind this process is explained, and the structure-performance relationship is elucidated through various characterization methods. The energy density of the assembled NF@Ni/rGO-MnO2//NF supercapacitor device can reach 136.3 Wh<middle dot>kg(-1) and the power density can reach 625 W<middle dot>kg(-1). This approach based on the Gugliemi model offers a promising strategy for developing high-performance supercapacitor electrode materials.