(378w) Understanding the Single Pass Operation of Vrfb and the Associated Mass Transfer Loss

All vanadium redox flow batteries have been recognised as an ideal energy storage device for large scale storage requirements. VRFB uses a common reservoir to store the electrolyte entering and exiting the electrodes. This results in the continuous variation of reactant concentrations and potential during a constant current operation. A constant or steady state performance can be achieved if the inlet concentration would remain constant. This is conventionally not implemented because of the larger volume of storage required and the necessity of an optimized geometry and operating parameters such that the inlet electrolyte is completely consumed within a single pass. There is also a large concentration loss associated with the low flow rates required.

The present work aims at understanding the concentration losses associated with a single pass operation with the aid of a simple lumped parameter model [1] modified to incorporate reservoir model, spatial variation, and mass transfer losses. VRFB performance optimization results based on an analysis of the integrated model will be presented. An optimum inlet concentration profile for the efficient implementation of a single pass operation will also be investigated.

References

1. Deepa Elizabeth Eapen, Suman R. Choudhury, and Raghunathan Rengaswamy. "Low grade heat recovery for power generation through electrochemical route: Vanadium Redox Flow Battery, a case study." Applied Surface Science (2018).