Core-shell hetero-nanostructured 1D transition metal polyphosphates decorated 2D bimetallic layered double hydroxide for sustainable hybrid supercapacitor

In this work, a hierarchical 2D NiMn-layered double hydroxide (LDH) @1D transition metal polyphosphates (1D NiCoP₂O₇) nanostructure is rationally prepared for hybrid sustainable supercapacitor to overcome the limitation of the traditional carbon-based supercapacitor. Initially, the vertically aligned 1D NiCoP₂O₇ hexagonal microrods are prepared over 3D nickel foam and then it is decorated with 2D NiMn-LDH nanoflakes to form core-shell nanostructure. Benefiting from the micro-nano structure, 2D NiMn-LDH@NiCoP₂O₇- core-shell electrode exhibits excellent electrochemical features with reversible charge storage specific capacity of 662.95 mAh g⁻¹ and excellent rate capability, which is quite suitable for the high-energy hybrid supercapacitor fabrication. The accumulated hybrid supercapacitor consisting of 2D NiMn-LDH@NiCoP₂O₇ and activated carbon achieves a high specific capacitance of 142.1 F g⁻¹, delivers remarkable specific energy (56.15 Wh kg⁻¹ at a specific power of 4210 W kg⁻¹) and endured superior cyclic stability over 10000 cycles. Such remarkable results may provide a new perspective for the development of supercapacitive electrode from metal oxide materials.