Modeling of ion transport through a porous separator in vanadium redox flow batteries

X. L. Zhou, T. S. Zhao, Liang An, Y. K. Zeng, L. Wei

Research output: Journal article publicationJournal articleAcademic researchpeer-review

49 Citations (Scopus)

Abstract

In this work, we develop a two-dimensional, transient model to investigate the mechanisms of ion-transport through a porous separator in VRFBs and their effects on battery performance. Commercial-available separators with pore sizes of around 45 nm are particularly investigated and effects of key separator design parameters and operation modes are explored. We reveal that: i) the transport mechanism of vanadium-ion crossover through available separators is predominated by convection; ii) reducing the pore size below 15 nm effectively minimizes the convection-driven vanadium-ion crossover, while further reduction in migration- and diffusion-driven vanadium-ion crossover can be achieved only when the pore size is reduced to the level close to the sizes of vanadium ions; and iii) operation modes that can affect the pressure at the separator/electrode interface, such as the electrolyte flow rate, exert a significant influence on the vanadium-ion crossover rate through the available separators, indicating that it is critically important to equalize the pressure on each half-cell of a power pack in practical applications.
Original languageEnglish
Pages (from-to)67-76
Number of pages10
JournalJournal of Power Sources
Volume327
DOIs
Publication statusPublished - 30 Sep 2016
Externally publishedYes

Keywords

  • Flow battery
  • Ion-transport mechanism
  • Numerical modeling
  • Porous separator
  • Vanadium-ion crossover

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

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