Hierarchical NiCo-LDH layered composite on PANI coated Ni foam for highly efficient supercapattery applications

Abstract

Supercapatteries combine the high-power density characteristic of supercapacitors with the high energy density typically found in batteries, offering a promising solution for advanced energy storage applications. We present an efficient two-step method to fabricate hierarchical, binder-free NiCo layered double hydroxide (LDH) nanosheet arrays supported on polyaniline layered nickel foam (NF). A PANI@NiCo-LDH/NF nanocomposite serves as the anode in the supercapattery, leveraging the high capacitance and improved conductivity of the combined materials, yielding a significantly high specific capacity of 1481 C g⁻¹ (3703.33 F g⁻¹). Coffee grounds derived reduced graphene oxide (rGO), providing a sustainable and environmentally friendly material with excellent electrical conductivity and high mechanical strength, serves as the cathode. The synergy between the PANI@NiCo-LDH/NF anode and the rGO cathode creates a novel and highly efficient supercapattery system. The fabricated supercapattery device offers an energy density of 54.44 W h kg⁻¹ at a power density of 0.702 kW kg⁻¹ and exhibits good cyclability with capacitance retention of 84.88% and Coulombic efficiency of 77.68% over 5000 charging/discharging cycles. This innovative approach addresses the limitations of traditional energy storage devices, paving the way for more versatile and sustainable energy solutions.