Oxygen vacancies and N‐doping in organic–inorganic pre‐intercalated vanadium oxide for high‐performance aqueous zinc‐ion batteries

Abstract

Pre‐intercalation of metal ions into vanadium oxide is an effective strategy for optimizing the performance of rechargeable zinc‐ion battery (ZIB) cathodes. However, the battery long‐lifespan achievement and high‐capacity retention remain a challenge. Increasing the electronic conductivity while simultaneously prompting the cathode diffusion kinetics can improve ZIB electrochemical performance. Herein, N‐doped vanadium oxide (N‐(Zn,en)VO) via defect engineering is reported as cathode for aqueous ZIBs. Positron annihilation and electron paramagnetic resonance clearly indicate oxygen vacancies in the material. Density functional theory (DFT) calculations show that N‐doping and oxygen vacancies concurrently increase the electronic conductivity and accelerate the diffusion kinetics of zinc ions. Moreover, the presence of oxygen vacancies substantially increases the storage sites of zinc ions. Therefore, N‐(Zn,en)VO exhibits excellent electrochemical performance, including a peak capacity of 420.5 mA h g−1 at 0.05 A g−1, a high power density of more than 10 000 W kg−1 at 65.3 Wh kg−1, and a long cycle life at 5 A g−1 (4500 cycles without capacity decay). The methodology adopted in our study can be applied to other cathodic materials to improve their performance and extend their practical applications.

Electrode/electrolyte interfacial engineering for aqueous Zn‐ion batteries

“…[24] Due to the distortion of V−O polyhedra, vanadium oxides give rise to a variety of structural frameworks, including VO 4 tetrahedron, VO 5 square pyramid, and VO 6 octahedron. [25,26] Another widely investigated cathode materials group is PBAs. With an open-framework structure and threedimensional (3D) channels, PBAs allow a rapid ion migration with little structural change.…”

Interfacial Defect Engineering Triggered by Single Atom Doping for Highly Efficient Electrocatalytic Nitrate Reduction to Ammonia

“…25 To meet these formidable challenges, heteroatom-doping is regarded as an effective approach to optimize the electronic structure of transition metal oxides, thus achieving highly efficient electrocatalytic performance. 26 In this context. the isolated single heteroatoms embedded in supports with much higher atomic utilization, tunable localized coordination state, and distinct activity could permit to selectively adsorb nitrogenous intermediate and prevent the N−N coupling pathway toward N 2 byproducts for the absence of an active neighboring site, which significantly promotes the selectivity toward nitrate-to-ammonia conversion.…”

“…Transition metal oxides have been extensively investigated as electrocatalysts for its attractive catalytic activity and electrochemical durability. − However, its performance is restricted by its poor electrical conductivity and limited catalytic active sites availability . To meet these formidable challenges, heteroatom-doping is regarded as an effective approach to optimize the electronic structure of transition metal oxides, thus achieving highly efficient electrocatalytic performance . In this context.…”

Regulation of the Electrochemical Plating/Stripping Process for Zn: Multifunctional Effects of N, S-Codoped Carbon Dots

“…22,23 Nitrogen doping can reduce the diffusion barrier and accelerate the migration of Zn 2+ ions. 24 In addition, nitrogen-and sulfur-containing groups are negatively charged, which can bind to zinc ions, inducing spacious nucleation of zinc and suppressing zinc-dendrite formation. In addition, oxygen-containing functional groups on the surfaces of carbon dots, such as −COOH, can reduce the activity of free water and thus inhibit side reactions.…”

“…Carbon dots (CDs) are a new kind of carbon material with a size less than 10 nm, composed of carbon core and surface functional groups, a large quantity of which are unsaturated functional groups, mainly including oxygen-containing functional groups generally, such as hydroxyl and carboxyl groups. , Initially, CDs were used for drug delivery and ion detection due to their good biocompatibility and photoluminescence performance; CDs have successfully drawn much attention in various energy-storage systems in recent years due to their small quantum size, rich surface functional groups, low-toxicity, adjustable structure and composition. , Nitrogen doping can reduce the diffusion barrier and accelerate the migration of Zn 2+ ions . In addition, nitrogen- and sulfur-containing groups are negatively charged, which can bind to zinc ions, inducing spacious nucleation of zinc and suppressing zinc-dendrite formation.…”