Hydration structures of vanadium/oxovanadium cations in the presence of sulfuric acid: A molecular dynamics simulation study

Effect of Inorganic Additive Strategy on the Stability of VO2+ in Vanadium Redox Flow Battery Electrolyte by Molecular Dynamics

Inorganic ions are considered to be effective additives to improve the temperature stability of all-vanadium redox flow batteries. In this study, molecular dynamics simulation has been performed to study the solvation structure and dynamic properties of VO2+ in the positive electrolyte by doping Na+, K+, and NH4+ in the presence of V2O5 precipitation. The results show that VO2+ ions aggregate into chainlike clusters in the electrolyte due to the induction of SO42-. The additives, which are stable in the solvation layers of VO2+, can work as protective shells to inhibit cluster growth. NH4+ is a superior dispersant compared with Na+ and K+ as it can stably exist in both the first solvation layer and the second solvation layer of VO2+. This work performed the molecular dynamics simulation of the electrolyte of vanadium redox flow batteries, and it gives some insights into the theoretical study of the modification of the cathode electrolyte.

Low-current-density stability of vanadium-based cathodes for aqueous zinc-ion batteries

Vanadium-based cathodes have received widespread attention in the field of aqueous zinc-ion batteries, presenting a promising prospect for stationary energy storage applications. However, the rapid capacity decay at low current densities has hampered their development. In particular, capacity stability at low current densities is a requisite in numerous practical applications, typically encompassing peak load regulation of the electricity grid, household energy storage systems, and uninterrupted power supplies. Despite possessing notably high specific capacities, vanadium-based materials exhibit severe instability at low current densities. Moreover, the issue of stabilizing electrode reactions at these densities for vanadium-based materials has been explored insufficiently in existing research. This review aims to investigate the matter of stability in vanadium-based materials at low current densities by concentrating on the mechanisms of capacity fading and optimization strategies. It proposes a comprehensive approach that includes electrolyte optimization, electrode modulation, and electrochemical operational conditions. Finally, we presented several crucial prospects for advancing the practical development of vanadium-based aqueous zinc-ion batteries.

A V(iii)-induced metallogel with solvent stimuli-responsive properties: structural proof-of-concept with MD simulations

A new solvent stimuli-responsive metallogel (VGel) was synthesized through the introduction of vanadium ions into an adenine (Ade) and 1,3,5-benzene tricarboxylic acid (BTC) organogel, and its supramolecular self-assembly was investigated from a computational viewpoint. A relationship between the synthesized VGel integrity and the self-assembly of its components is demonstrated by a broad range of molecular dynamics (MD) simulations, an aspect that has not yet been explored for such a complex metallogel in particular. MD simulations and Voronoi tessellation assessments, both in agreement with experimental data, confirm the gel formation. Based on excellent water stability and the ethanol/methanol stimuli-responsive feature of the VGel an easy-to-use visualization assay for the detection of counterfeit liquor with a 6% (v/v) methanol limit of detection in 40% (v/v) ethanol is reported. These observations provide a cheap and technically simple method and are a step towards the immersible screening of similar molecules in methanol-spiked beverages.

A new solvent stimuli-responsive metallogel (VGel) was synthesized through the introduction of vanadium ions into an adenine (Ade) and BTC organogel, and its supramolecular self-assembly was investigated from a computational viewpoint.