Designing FeCoP@NiCoP heterostructured nanosheets with superior electrochemical performance for hybrid supercapacitors

The precise preparation of transition metal phosphides-based battery-type electrode materials with well-defined morphology and nanostructure have shown great potential in supercapacitors, due to their high electrical conductivity and superior redox activity. Herein, a smart nanoarchitecture comprised of a FeCoP@NiCoP core-shell hybrid is designed via a two-step electrodeposition strategy together with a phosphorization treatment. The 3D FeCoP@NiCoP nanosheet arrays grown on a flexible carbon cloth substrate can provide an efficient nanoporous framework, facilitate the electron/ion transport, and generate the effective synergy of good conductivity from FeCoP and superior redox activity from NiCoP. As a result, the as-prepared FeCoP@NiCoP electrode exhibits a high specific capacity of 973.0 C g(-1) at a low current density of 1 A g(-1) and excellent rate capacibity with 84.3% retention at 20 A g(-1), superior to those of bare FeCoP and NiCoP electrodes. Additionally, a hybrid supercapacitor is assembled with FeCoP@NiCoP as a cathode and a barley-derived hierarchical porous carbon BPC-800 as an anode, showing a high energy density of 75.9 Wh kg(-1) at a power density of 827.8 W kg(-1) and outstanding cycling stability of 89.7% retention of the initial capacitance after 10000 cycles.

Automated summary

By designing a smart nanoarchitecture comprised of a FeCoP@NiCoP core-shell hybrid, with efficient nanoporous framework and good conductivity from FeCoP and superior redox activity from NiCoP, the prepared electrode shows high specific capacity and excellent rate capability in supercapacitors. Additionally, the hybrid supercapacitor assembled with FeCoP@NiCoP as a cathode exhibits high energy density and outstanding cycling stability.