Metal-organic framework-derived (Mn-1)Co_xS_y@(Ni–Cu)OHs marigold flower-like core@shell as cathode and (Mn–Fe₁₀)S_x@graphene–foam as anode materials for ultra-high energy-density asymmetric supercapacitor

Energy density, rate-capability and cycling stability performance of asymmetric supercapacitors (ASCs) can be improved by engineering the rational design of both cathode and anode electrodes materials-based on hierarchical structures. The fabrication of metal-organic-frameworks (MOFs)-derived hierarchical core@shell nanosheet arrays is undoubtedly a crucial task; however, their development is important to promote efficient asymmetric supercapacitor devices. Herein, we are reporting MOF-derived (Mn-1)Co_xS_y nanosheet arrays enfolded with unique marigold flower-like nanoreservoirs of (Ni–Cu)OHs as a novel core@shell-based cathode material for asymmetric supercapacitor. In the presence of the highly conductive, porous and uniquely structured (Ni–Cu)OHs shell material, the multicomponent (Mn-1)Co_xS_y@(Ni–Cu)OHs core@shell nanosheet arrays deliver an ultra-high areal capacity of 2.19 mA h cm⁻² at 1 mA cm⁻². Newly developed (Mn–Fe₁₀)S_x@GF hybrid film with enriched redox contributions is used as an anode material to configure the ASC device. The (Mn-1)Co_xS_y@(Ni–Cu)OHs//(Mn–Fe₁₀)S_x@GF ASC device delivers an ultra-high energy density performance of 95.25 W h/kg at a power density of 963.2 W k/g with capacity retention of 92.08% after 10,000 cycles. Thus, the successful syntheses of multicomponent-based (Mn-1)Co_xS_y@(Ni–Cu)OHs core@shell as cathode and (Mn–Fe₁₀)S_x@GF as anode electrode materials with excellent electrochemical outcomes have given new directions to develop ultra-high performance asymmetric supercapacitors.