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

Abstract 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.