Heterostructured metallic electrode materials fabricated by altering the structurally engineered morphologies are promising in ameliorating electrodes' functionality in energy storage applications. Effective and novel double-shell sandwich-like NiCO3/NiMnO3-rGO-Co3O4 (Ni-NMO-rGO-CoO) nanoflake array (NFA) heterostructures were prepared on highly conducting 3D Ni foam using a two-step hydrothermal process. rGO wrapping on the NiCO3 embedded NiMnO3 (Ni-NMO) nanocomposite flakes improved the cycling stability and avoided volume expansion by acting as an interlayer. The surface decorated Co3O4 nanograins showed a uniform distribution over the rGO wrapped Ni-NMO and facilitated the pathways for fast ion diffusion kinetics to enhance the specific capacity of the electrode. The layer to layered Ni-NMO-rGO-CoO NFA electrode yielded an ascendant specific capacity of 188.8 mA h g−1 (3.9 F cm−2) at 1 mA g−1. The fabricated all-solid-state Ni-NMO-rGO-CoO//AC hybrid supercapacitors (HSCs) showed a superior energy density of 57.2 W h kg−1 at 472.2 W kg−1 with 97.7% capacitance retention after 10 000 cycles. The fabricated HSCs have potential applications in portable electronics. The Ni-NMO-rGO-CoO NFA ternary layered architecture offers a promising approach for fabricating high-performance hierarchical composite array electrodes for next-generation energy storage devices.