Template-free electrodeposition of sponge-like porous polymer interwoven with the bi-metallic metal-organic framework and reduced graphene oxide and application in energy storage device

In this research, an effective template- and binder-free strategy was developed for the design and fabrication of hybrid-structure supercapacitor (HSSC) material based on the novel sponge-like porous polymer enclosed with the bi-metallic metal-organic framework (bi-MMOF) and reduced graphene oxide (RGO) films. For the implementation of this goal, the green, in-situ, and eco-friendly electrochemical deposition technique was employed to modification of the gold surface with the reduced graphene oxide (RGO), poly-dibenzoazepine (PDB) polymer, and Ni/Co bi-metallic metal-organic (bi-MMOF) films, respectively. This procedure was accomplished without the use of any binder, template, pretreatment, and chemical modification of the substrate in an aqueous solution and at room temperature. According to our hypothesis, the synergic effect of conductivity and electrochemical double-layer capacitance (EDLC) of reduced graphene oxide along with the conductivity and pseudocapacitive behaviour of water-stable Ni/Co bi-MMOF, and the high surface area of polymer can be provided enhanced supercapacitor features. The electrochemical surveys indicated the superior performance of the designed nanocomposite with a suitable specific capacitance of 686.0 F g−1 at 1.0 A g−1 and suitable rate performance 554.0 F g−1 at 8.0 A g−1. Also, the assembled symmetric hybrid-structure supercapacitor appeared suitable energy density of 8.4 Wh kg−1 at 200 W kg−1 power density and satisfied specific capacitance of 378.0 F g−1 at 0.5 A g−1 with extraordinary long-life stability (95.1 % capacity retention up to 5000 cycles). These outcomes illustrated the proposed procedure can be shed light on designing new Graphene-Polymer-MMOF configured supercapacitors. •Employed the eco-friendly electrochemical deposition technique as a template-free strategy for design of supercapacitor.•Report a new nano-composite based on sponge-like porous polymer interwoven with the RGO and bi-MMOF.•Symmetric supercapacitor device with SC of 378.0 F g−1 at 0.5 A g−1, and 95.1% cycle stability after 5000.