Optimizing nanostructure and constructing heterostructure via Mo/W incorporation to improve electrochemical properties of NiCoP for hybrid supercapacitors

Transition metal phosphides (TMPs) are promising battery-type electrodes for hybrid supercapacitors (HSCs) due to their high electrical conductivity and electrochemical activity. Constructing TMPs with fast kinetics stable structure is requisite realize high-performance HSCs but remains a challenge. Herein, we incorporate Mo (or W) into NiCoP form Ni-Co-Mo-P Ni-Co-W-P) heterostructures unique three-dimensional (3D) open morphology modified electronic structure. Electrochemical analyses density functional theory (DFT) calculations reveal that the incorporation of Mo/W enables optimized nanostructure, conductivity, abundant reaction active sites enhanced kinetics. As result, designed heterostructure delivers areal capacity 4.08 C cm−2 (703 g−1) at 2 mA 3.25 30 good cycling stability, superior those Ni-Co-W-P counterparts. The practical feasibility further demonstrated by an energy conversion storage system consisting commercial solar cell Ni-Co-Mo-P//activated carbon (AC) device, which could obtain 53.3 W h kg−1 power 800 kg−1. All-solid-state Ni-Co-Mo-P//AC device illustrates flexibility makes strong candidate wearable electronics.