Multicomponent Hybridization Transition Metal Oxide Electrode Enriched with Oxygen Vacancy for Ultralong-Life Supercapacitor.

Transition metal oxide electrode materials for supercapacitors suffer from poor electrical conductivity and stability, which are the research focus of the energy storage field. Herein, multicomponent hybridization Ni-Cu oxide (NCO-Ar/H 2 -10) electrode enriched with oxygen vacancy and high electrical conductivity including the Cu 0.2 Ni 0.8 O, Cu 2 O and CuO is prepared by introducing Cu element into Ni metal oxide with hydrothermal, annealing, and plasma treatment. The NCO-Ar/H 2 -10 electrode exhibits high specific capacity (1524 F g -1 at 3 A g -1 ), good rate performance (72%) and outstanding cyclic stability (109% after 40,000 cycles). The NCO-Ar/H 2 -10//AC asymmetric supercapacitor (ASC) achieves high energy density of 48.6 Wh kg -1 at 799.6 W kg -1 while exhibiting good cycle life (117.5% after 10,000 cycles). The excellent electrochemical performance mainly comes from the round-trip valence change of Cu + /Cu 2+ in the multicomponent hybridization enhance the surface capacitance during the redox process, and the change of electronic microstructure triggered by a large number of oxygen vacancies reduce the adsorption energy of OH - ions of thin nanosheet with crack of surface edge, ensuring electron and ion-transport processes and remitting the structural collapse of material. This work provides a new strategy for improving the cycling stability of transition metal oxide electrode materials.