Controlled phase engineering of Fe doped NiCoLDH with 1D/2D hierarchical nanostructure for high energy density supercapacitors

Synergistic interactions among various components, along with deliberate structural optimization, can finely tune the electronic properties and accelerate reaction kinetics, leading to a marked improvement in electrode material performance. In this work, we report the synthesis of Fe-doped NiCo-layered double hydroxides (LDH) nanosheet heterojunctions featuring a well-engineered two/three-dimensional (2D/3D) hierarchical architecture designed to suppress aggregation and layer restacking, thereby facilitating efficient ion intercalation and extraction during electrochemical processes. The Fe_0.05/NiCoLDH electrode exhibits an outstanding specific capacitance of 2861 F g⁻¹ at a current density of 1 A g⁻¹. The assembled hybrid supercapacitor (Fe_0.05/NiCoLDH//activated carbon) delivers a high energy density of 83 Wh kg⁻¹ at a power density of 792 kW kg⁻¹, along with excellent cycling stability, maintaining 89% capacitance retention after 1000 charge–discharge cycles. This study demonstrates that Fe_0.05/NiCoLDH devices, featuring a stable multi-component hierarchical architecture and enhanced electrical conductivity, offer a promising approach to improving the electrochemical performance of supercapacitors.