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/H2‐10) electrode enriched with oxygen vacancy and high electrical conductivity including the Cu0.2Ni0.8O, Cu2O and CuO is prepared by introducing Cu element into Ni metal oxide with hydrothermal, annealing, and plasma treatment. The NCO‐Ar/H2‐10 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/H2‐10//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+/Cu2+ 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.

Enhancing acidic hydrogen evolution through pyrrolic nitrogen-doped reduced graphene oxide triggering two-electron oxygen reduction

“…In Fig. 5b, the Ni 2p spectra of Ni/N/O-rGO-1/Ni-275h exhibit two splitting peaks of Ni 2+ 2p 1/2 (873.6 eV) and Ni 2+ 2p 3/2 (856.0 eV), 61 closely resembling the NiO film on the fresh Ni plate. However, no Ni 0 signal peak (853.3 eV) is observed in Ni/N/O-rGO-1/Ni-275h, 62 indicating the complete transformation of the initial Ni 0 into a high valence state.…”

Nanoflower-like NiCo2O4 Composite Graphene Oxide as a Bifunctional Catalyst for Zinc–Air Battery Cathode

“…However, in practical applications, pure nanoflower-like NiCo 2 O 4 did not exhibit an impressive catalytic performance, possibly due to the following reasons. One reason is that although the doping of Ni enhances the conductivity of NiCo 2 O 4 compared to Co 3 O 4 , its inherent low conductivity remains unavoidable, resulting in a lack of rapid kinetics . Another reason is the aggregation issue of nanoflower-like NiCo 2 O 4 during the catalytic process, which may result in insufficient contact with the electrolyte and air, leading to inadequate exposure of active sites, consequently reducing catalytic activity .…”

“…One reason is that although the doping of Ni enhances the conductivity of NiCo 2 O 4 compared to Co 3 O 4 , its inherent low conductivity remains unavoidable, resulting in a lack of rapid kinetics. 17 Another reason is the aggregation issue of nanoflower-like NiCo 2 O 4 during the catalytic process, which may result in insufficient contact with the electrolyte and air, leading to inadequate exposure of active sites, consequently reducing catalytic activity. 18 These issues might lead to the poor catalytic performance of pure nanoflower-like NiCo 2 O 4 in practical applications.…”

The role of Mn in widening the potential window of solid solution derived electrodes for aqueous supercapacitors

“…10,11 To date, many strategies are centered on complicated structure and composition electrode design to enhance the specific capacitance, which limits their scale up. 12–14 The design of asymmetric supercapacitors (ASCs) is the primary approach to broaden the operating voltage, which are typically assembled with low capacity carbon materials and require additional capacity matching. 15–17 Consequently, how to further enhance the energy density of NiO-based symmetric pseudocapacitors through a simple and practical way has become more imperative.…”