Boosting the Rate Capability of Aqueous Zinc-Ion Batteries Using VN_xO_y/C Spheres Derived from a Self-Assembled V-polydopamine Complex

Abstract

While vanadium oxides have garnered interest due to their high capacity and abundant valence states in aqueous zinc-ion batteries (AZIBs), there are many challenges to achieving long cycling stability and excellent rate capability resulting from poor electronic conductivity and sluggish reaction dynamics. Herein, we design a cathode material VN x O y /C derived from a self-assembled V-polydopamine complex via a one-step organic–inorganic hybrid reaction. Benefiting from a well-organized structure and nanosized particle embedding, the as-prepared VN x O y phase could favor zinc-ion insertion/extraction due to the strong affinity of N element with Zn2+. Systematic investigations show that the controllable strategy yields positive effects on the electrochemical performances including enhanced rate capability and cycling stability, which are superior to those of the V2O3/C cathode. As a result, we have achieved fast charging/discharging capability at 10 A g–1 and stability exceeding 700 cycles at 3 A g–1 with nearly 100% Coulombic efficiency. Interestingly, the pouch-cell-like devices with ∼24 mAh could light an LED effectively. This work may pave the way to obtaining highly active V-containing compounds with structure design to improve electrochemical performances of AZIBs.

Anchoring Polar Organic Molecules in Defective Ammonium Vanadate for High‐Performance Flexible Aqueous Zinc‐Ion Battery

“…The assembled device is capable of delivering an ultrahigh energy density of 436 Wh kg −1 at a power density of 400 W kg −1 , exceeding most previously reported aqueous ZIBs. [44,67,[70][71][72][73][74][75][76] The gravimetric energy density remains 180 Wh kg −1 at an ultrahigh power density of 4000 W kg −1 , signifying that our FARZIBs can simultaneously demonstrate high energy and power densities. To test the application of FARZIB in flexibility, we repeatedly bend FARZIBs, and measure its capacity retention at different bending angles.…”

Metal‐Organic Assembly Strategy for the Synthesis of Layered Metal Chalcogenide Anodes for Na+/K+‐Ion Batteries

“…As a result, nanostructure engineering and carbon modification can be achieved in one‐step. According to the structure features, the metal‐organic assembly can be roughly divided into three categories: ordered metal‐organic frameworks (MOFs) composed of metal ion/cluster and functional ligands, [89–98] metal‐organic polymers formed by polymerization reaction of metal ions and monomers, [99–112] metal‐organic coordination polymer chelated by metal ion and small organic molecules [113–129] …”

“…[94,98] As a result, nanostructure engineering and carbon modification can be achieved in one-step. According to the structure features, the metal-organic assembly can be roughly divided into three categories: ordered metal-organic frameworks (MOFs) composed of metal ion/cluster and functional ligands, [89][90][91][92][93][94][95][96][97][98] metalorganic polymers formed by polymerization reaction of metal ions and monomers, [99][100][101][102][103][104][105][106][107][108][109][110][111][112] metal-organic coordination polymer chelated by metal ion and small organic molecules. [113][114][115][116][117][118][119][120][121][122][123][124][125][126][127][128][129] MOFs are highly ordered and porous crystalline framework structures, constructed by coordination bonds between metal nodes and organic linkers, have been widely employed as self templates to build MX-based nanohybrids.…”

“…Different from ligand linkers, some organic monomer molecules can chelate with metal ions and take the polymerization reactions in the meantime, producing metal-organic polymers with specific nanostructures. Mo, W and V-ions can be coordinated with pyrrole or dopamine monomers and create monodispersed metal-organic polymers, such as Mo-Polydopamine(PDA), [99][100][101] W-PDA, [102][103][104] V-PDA, [105] Polypyrrole (PPy)-PMo 12 , [72,[106][107][108] PPy-PW 12 , [106] MoO 3 -PDA, [109,110] and Ni/Mo-PDA. [111] Recently, dopamine has been widely used as the monomer to load the metal ions through the coordination bond, benefited from the advantages of abundant catechol groups, strong coordination bonds to various metal ions and ).…”