Rational design of three-dimensional branched NiCo-P@CoNiMo-P core/shell nanowire heterostructures for high-performance hybrid supercapacitor

Owing to the dramatically enhanced charge-mass transport and abundant electrochemically active sites, transition metal compound electrodes are increasingly attractive for achieving high-performance supercapacitors (SCs). Here, we report the fabrication of nickel foam supported three-dimensional (3D) branched nickel-cobalt phosphides@tri-metal cobalt-nickel-molybdenum phosphides core/shell nanowire heterostructures (denoted as NiCo-P@CoNiMo-P) as high-performance electrode materials for hybrid supercapacitors. The presence of multiple valences of the cations in such NiCo-P@CoNiMo-P enables rich redox reactions and promoted synergy effects. Benefiting from their collective effects, the resulting electrode demonstrates high specific capacity of 1366 C g(-1) at 2 A g(-1) (2.03 C cm(-2) at 2 mA cm(-2)) and 922 C g(-1) at 10 A g(-1), as well as good cycling stability (retaining similar to 94% of the initial capacity after 6000 cycles at 15 A g(-1)). A hybrid SC using the NiCo-P@CoNiMo-P as the positive electrode and N-doped rGOs as the negative electrode exhibits a high energy density of 81.4 Wh kg(-1) at a power density of 1213 W kg(-1) and a capacity retention of 132% even after 6000 cycles at 10 A g(-1). Our findings can facilitate the material design for boosting the performance of transition metal compounds based materials for fast energy storage. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

A novel high-performance electrode material NiCo-P@CoNiMo-P was reported in this study, which exhibited rich redox reactions and synergy effects, resulting in high specific capacity and good cycling stability. The hybrid supercapacitor using this electrode material showed high energy density and long cycle life.