Species Uptake and Mass Transport in Membranes for Vanadium Redox Flow Batteries

Abstract

In this contribution, we provide a synthesis of results to date describing uptake and mass transport of water, vanadium species and protons in Nafion membranes for use as separators in VRFBs. Resistance issues as well as species cross-over are important contributors to performance loss in VRFBs. After a brief discussion of our state-of-theart cell performance, we consider the uptake and transport of various species through a number of membrane materials. We draw together numerous previous studies and augment them with new data to provide a summary of our present state of understanding of the experimental facts regarding membrane behavior.

Vanadium Redox Flow Batteries: Electrochemical Engineering

“…This results from reduced ohmic loss and enhanced localized mass transfer due to thinner thickness and larger surface area-to-volume ratio of carbon paper used as electrode than those of carbon felt. Elgammal et al [30] achieved normalized limiting current density of 2961 mA/cm 2 mol and peak power density of 2588 mW/ cm 2 of VRFB with serpentine flow field. However, "flow-through" configuration distributes the electrolyte flow more uniformly and results in less pressure drops and pumping losses than "flow-by" configuration.…”

The Effect of Sulfuric Acid Concentration on the Physical and Electrochemical Properties of Vanadyl Solutions

“…Flow batteries, including the all-vanadium redox flow battery (VRFB), have recently received considerable attention as a possible solution to large grid energy storage needs [1]. Numerous experimental [2] and modeling studies [3] have been conducted to understand and improve flow battery technology. A detailed understanding of the electrolyte dynamics and how they change with parameters like temperature and concentration is an important fundamental step in flow battery research [4][5][6].…”

A review of all‐vanadium redox flow battery durability: Degradation mechanisms and mitigation strategies

“…A standard test procedure to measure vanadium ion crossover was developed by Skyllas‐Kazacos et al To eliminate any interference from water transport due to osmotic pressure effects across the membrane, ex situ testing procedures were also developed . Typically, the membrane is sandwiched between two half‐cells with gaskets on either side to prevent solution leakage . One half‐cell contains VOSO 4 solution, and the other half cell contains MgSO 4 solution.…”

“…68,84,85,94 Typically, the membrane is sandwiched between two half-cells with gaskets on either side to prevent solution leakage. 89 One half-cell contains VOSO 4 solution, and the other half cell contains MgSO 4 solution. The MgSO 4 solution is sampled periodically to measure the increasing V(IV) concentration using a UV/Vis spectrophotometer; from this, the permeability of the V(IV) ions through the membrane can be calculated.…”