Testing of the 5 kW Battery System 

In early September, a 5 kWh redox flow battery system was successfully installed and initiated at the research laboratory at the University of Pavol Jozef Šafárik in Košice. Shortly thereafter, the Pinflow Energy Storage team conducted an insightful training session. The participants included members of the INO-HUB R&D team — Dr. Tomas Kosicky, Dr. Igor Derr, and Dr. Elena Romadina; and our collaborators from UPJS University, Dr. Andrea Strakova Fedorkova and Dr. Natalia Podrojkova.

This redox flow battery testing setup comprises a 40-cell battery stack; tanks and pumps for the electrolyte; flow, pressure, and temperature sensors, and 200 Liters of vanadium electrolyte. The battery boasts a nominal energy capacity of 5 kWh.

The battery setup is connected to a programmable bidirectional power supply with an 80V voltage range and a 340A current range. Our primary objective was to evaluate the battery performance under various charge-discharge cycling conditions. Initial cycling at 3 kW and 5 kW revealed battery energy efficiencies of 88% and 80%, respectively.

These experiments provided the reference data on the battery stack performance. In future experiments, this setup will be used as an important tool for battery upscaling and optimization. It could be used for battery stack testing, investigation of the different electrolyte performance, testing of variations in vanadium electrolyte chemistry, and studying the impact of external and internal conditions, for example, temperature or electrolyte flow rate, on battery performance.


This work was supported by the project: IPCEI_IE_FLOW_BESS_012021