Graphite felt is a widely used electrode material for vanadium redox flow batteries. Electrode activation leads to the functionalization of the graphite surface with epoxy, OH, C=O, and COOH oxygenic groups and changes the carbon surface morphology and electronic

structure; thus, improving the electrode’s electroactivity relative to the untreated graphite. In this study, we conduct density functional theory (DFT) calculations to evaluate functionalization’s

role towards the positive half-cell reaction of the vanadium redox flow battery. The DFT calculations show that oxygenic groups improve the graphite felt’s affinity towards the VO²⁺/VO2⁺ redox couple in the following order: C=O > COOH > OH > basal plane. Projected density of states (PDOS) calculations show that these groups increase the electrode’s sp³hybridization in the same order. We conclude that the increase in the sp³ hybridization is responsible for the improved electroactivity, while the oxygenic groups’ presence is responsible for this sp³ increment. These insights can help in the better selection of activation processes and optimization of their parameters.

Search

Refine Search

13 results in Piotr de Silva in Authors: Piotr de Silva

The Role of Oxygenic Groups and Sp3 Carbon Hybridization in Activated Graphite Electrodes for Vanadium Redox Flow Batteries

A Computational Protocol Combining DFT and Cheminformatics for Prediction of pH-Dependent Redox Potentials

A Unified Framework for Photophysical Rate Calculations in TADF Molecules

Triplet-to-Singlet Exciton Transfer in Hyperfluorescent OLED materials

Heavy-Atom-Free Room-Temperature Phosphorescent Organic Light-Emitting Diodes Enabled by Excited States Engineering

Molecular Engineering Strategies for Symmetric Aqueous Organic Redox Flow Batteries

On the Inverted Singlet-Triplet Gaps and Their Relevance to Organic Light-Emitting Diodes

Revealing Internal Heavy Chalcogen Atom Effect on the Photophysics of Dibenzo[a,j]phenazine-Cored Donor–Acceptor–Donor Triad

Regioisomeric Effect on the Excited-State Fate Leading to Room-Temperature Phosphorescence or Thermally Activated Delayed Fluorescence in a Dibenzophenazine-Cored Donor–Acceptor–Donor System

Revisiting the Role of Charge Transfer and Local Excitations in Thermally Activated Delayed Fluorescence

13 results in Authors: Piotr de Silva