Influence of tungsten ion in analyte for electrochemical performance of vanadium redox flow batteries

초록

Vanadium redox flow batteries (VRFBs) have been intensively studied to develop large-scale energy storage batteries system with advantages of environmental friendship, low cost of maintenance, high energy efficiency, and long cycle life. However, there are still drawbacks of VRFB in terms of its relatively poor energy density. Many studies have been reported to overcome energy density issue via improvement of electrodes, bipolar plate and electrolytes; modification of electrodes by electrodeposition, hydrothermal method, and spray coating as well as new additives in the electrolyte was suggested. Especially, synthesis of metal oxide catalyst on the electrode has attracted attentions as a facile medication method to improve VRFB. On the other hand, low conductivity of metal oxide, time-consuming synthesis routes and high cost procedure limited their application in the industrial field. Alternatively, adding metal catalyst ion in electrolyte has been researched to improve electrochemical performance for VRFB. Metal catalyst ion showed enhanced electrochemical performance via repeating deposition on the electrode and ionization into electrolyte during the cycle. In this study, we researched influence of tungsten ion in electrolyte to improve VRFB. We found that about 2 % energy efficiency was improved when the small amount of tungsten ions was added in the electrolyte.