Work

Vanadium redox flow batteries: Exploring stability with in-situ electrochemically produced nitric acid pretreated enhanced graphene-coated pencil graphite electrodes

Year: 2025

Type: article

Abstract: In this investigation, we explore diverse techniques for pre-treating pencil graphite electrodes (PGE) to optimize their performance in vanadium redox flow batteries (VRFBs). Our objective is to provide researchers with two straightforward yet effective methods for preparing the PGE surface for reduced graphene oxide (RGO) deposition. The graphene deposition process employs cyclic voltammetry (CV) in a 5 M HNO3 (Nitric Acid) solution. Introducing graphene oxide (GO) into the system before CV enables a more substantial conversion of graphite to RGO, enhancing the electrode’s performance and stability under VRFB working conditions, surpassing the efficacy of electrodes pretreated using a basic water washing method. Comparison results highlight the superiority of the HNO3 pre-treated PGE, achieving a peak reduction value of −0.73 A/cm 2 compared to −0.46 A/cm 2 for the Water PGE. The GO coated Pencil Graphite Electrode (GOPGE-2 days) exhibits a comparable −0.72 A/cm 2 , signifying an almost 60 % improvement in performance characteristics over the Water PGE. Additionally, characterization using LiClO4 demonstrates a remarkable 83 % increase in the charge-carrying capacity of the electrodes, extending to anodic and cathodic current density as well as redox capacity. Cyclic stability assessments in VOSO4 reveal a remarkable 274 % enhancement in charge-carrying capacity. This paper underscores the significance of a streamlined, one-step pre-treatment method, not only for optimal laboratory experimentation but also for superior performance in VRFBs and potentially other battery chemistries utilizing Graphene-Coated Pencil Graphite Electrodes (GPGE) as electrodes.

Source: Future Batteries

DOI: 10.1016/j.fub.2025.100065

Authors: Kanav Dang, D. Vidya, Balaji Krishnamurthy

Institutions: Birla Institute of Technology and Science - Hyderabad Campus, Birla Institute of Technology and Science, Pilani

Language: English

Topic: Advanced battery technologies research

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $1,950