Novel Graphene Wrapped Ni-Co Layered Double Hydroxides Electrode for High Performance Hybrid Supercapacitors

Limited reserve of fossil fuels is a big issue to fulfill the energy need by society in the current scenario. Moreover, the used of fossil fuels causes the emission of greenhouse gases. Therefore, these issues are leading concerns for modern society. The use of renewable energy can solve the above problems but it needs energy storage devices (ESDs). Owing to its high cost, the implementation of ESDs are limited. The cost of ESDs can be reduced either using low-cost materials or enhancing the performance of the ESDs. Thus the investigation of high-performance ESDs is vital to fulfilling the energy need. Among the various electrical ESDs, the hybrid supercapacitors (HSCs) are most promising because it can deliver high-power-density along with high-energy-density. The layered double hydroxides (LDHs) received extensive consideration in HSCs owing to good ion-exchange property, structural flexibility and large surface area. Among the LDHs Ni-Co-based showed better specific capacitance, good synergy and high rate capability in aqueous electrolyte. However, LDHs suffers from low conductivity, which hampers the charge transfer and mass diffusion throughout the electrochemical process. Thus, the high performance of the LDH based supercapacitors is hindered. To overcome this issue composites of LDH and conducting materials is used. Owing to its extraordinary conducting property, huge surface area, and cost-effectiveness, reduced graphene oxide (rGO) is used as conducting material for LDH-rGO composite electrode. In this proposal, a novel composite cathode will be prepared by wrapping the Ni-Co-LDH with N and S co-doped rGO (rGO-NS). First, GO will be simultaneously reduced and co-doped with N and S and Ni-Co LDH nanostructure of Ni/Co ratio ~ 1:2 will be synthesized separately via solution process. Finally, the Ni-Co LDH nanostructure will be wrapped with rGO-NS. The synthesized Ni-Co LDH/rGO-NS will be characterized using various techniques i.e., XRD, SEM, TEM, TGA, FTIR, etc. The electrode will be evaluated using electrochemical characterization.