Facile synthesis of MnO2-Ni(OH)2 3D Ridge-like Porous Electrode Materials by Seed-induce Method for High-performance Asymmetric Supercapacitor

- The MnO2-Ni(OH)2 hybrids were successfully decorated on the Ni foam (MN-NF/AB).
- The as-obtained MN-NF/AB exhibits uniform 3D ridge-like structure due to PVDF/AB.
- The MN-NF/AB electrodes possess a high areal capacitance (10.15 F cm−2).
- The MN-NF/AB ASC devices possess superior capacitive behavior and long cycle life.

MnO2-based nanomaterials as the supercapacitor electrodes usually suffer from the poor electrical conductivity and electrochemical stability due to large volume expansion during the charge/discharge processes. In this study, the developed capacitance performance and improved long-term cycling stability of MnO2-based electrodes were obtained through designing MnO2-Ni(OH)2 three dimensional (3D) porous hierarchical hybrid nanocomposites (MN-NF/AB) grown on the nickel foam by the aid of conductive adhesive consisting of PVDF-acetylene black (AB) seed layer via a one-step scalable hydrothermal route. The unique 3D ridge-like nanostructures with the features of porous, interconnected active nanosheets and vertically growing on the 3D nickel foam exhibit a high areal capacity (4.86C cm−2) and areal capacitance (10.15 F cm−2) at 4 mA cm−2 in a three-electrode system, which can effectively eliminate the volume expansion-induced pulverization phenomenon for MnO2-based electrode materials, resulting in enhanced cycling stability. Furthermore, the assembled product-soft package of asymmetric supercapacitors (MN-NF/AB//active carbon) can have excellent energy storage capacity (3.62 mW h cm−3 at 11 mW cm−3) and a long-term cycling stability (86% of capacitance retention at 50 mA cm−2 after 10000 cycles).

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