ELECTROCHEMICAL AND SPECTROSCOPIC INVESTIGATION OF BLACK PEARLS CARBON ELECTRODE FOR VANADIUM REDOX FLOW BATTERY

Abstract

Redox flow battery (RFB) is emerging as an excellent choice for grid-scale electrical energy storage (EES) with many advantages over conventional batteries. Despite their advantages, RFBs suffer from high system capital cost and large footprint which limit their commercialization for grid storage applications. In the last few decades, great research efforts in the development of electrode-electrolyte for Vanadium Redox Flow Battery (VRFB) technology have been witnessed. The carbon of interest in our research was the cost-effective, commercial mesoporous carbon called Black Pearls 2000 (BP). The BP carbon black was found to have high surface area and enough oxygen functional groups that aid in both the negative and positive electrode reactions and proves to be kinetically fast and symmetrically reversible. Subsequently, nitric acid treatment increased the oxygen functional groups, specifically, carboxyl and hydroxyl groups which have helped improve the kinetics and reversibility of irreversible mesoporous carbon acetylene black (ACB) and graphitic Toray carbon paper in a vanadium redox system. The chemical and physical properties of all the carbon samples were characterized using XPS, FTIR, Raman spectroscopy and microscopic and BET surface area analysis respectively. In conclusion, while the excellent behavior of BP is attributed to the active sites with high content oxygen on the high surface area and low pore size, the induced defects due to acid treatments have increased the active sites with oxygen functional groups in ACB and Toray. Therefore, this research thesis attempts to present a conclusive answer to the conflicting results on carbon electrode behavior in VRFB by presenting the electrochemical and spectroscopic studies.

Date of Award	2019
Original language	American English
Awarding Institution	HBKU College of Science and Engineering