Enhanced cycle life of vanadium redox flow battery via a capacity and energy efficiency recovery method

L. Wei, X. Z. Fan, H. R. Jiang, K. Liu, M. C. Wu, T. S. Zhao

Research output: Journal article publicationJournal articleAcademic researchpeer-review

15 Citations (Scopus)

Abstract

In this work, the cycle life of vanadium redox flow batteries (VRFBs) is extended by resolving the inevitable loss of capacity and energy efficiency after long-term cycle operation. The electrolyte concentration, volume, and valence are rebalanced by mixing the electrolyte as well as adding a quantitative amount of a reducing agent. Without disassembling the battery, the energy efficiency decay induced by electrode degradations is almost completely restored by interchanging the positive and negative electrodes. By adopting this method, the capacity and energy efficiency after 500 cycles can be restored to 473 mAh and 90.8%, almost reaching the previous highest level at the beginning of the cycle test (478 mAh and 91.0%). In addition, the rate performance tests also demonstrate that even at a current density of as high as 300 mA cm−2, the energy efficiency of the recovered battery is only 0.8% lower than the new battery. All the results show that the recovery method reported here allows the cycle life of VRFBs to be greatly prolonged with no need to replace electrolytes and electrodes.

Original languageEnglish
Article number228725
JournalJournal of Power Sources
Volume478
DOIs
Publication statusPublished - 1 Dec 2020
Externally publishedYes

Keywords

  • Capacity decay
  • Energy efficiency loss
  • Oxalic acid dihydrate
  • Recovery method
  • Vanadium redox flow battery

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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