DegraBat - Degradation processes in All-Vanadium-Redox-Flow-Batteries

Motivation:

The Vanadium redox-flow-battery is a promising technology for renewable energy storage. Advantages are the independent scalability of power (cell/stack) and capacity (tank), low self-discharge and long service life. However, degradation of the battery components (electrodes, membrane, electrolyte, sealing) causes losses in capacity and power and shorter lifetime of the battery.

Summary

Within this joint project the degradation processes of components in vanadium redox-flow-batteries will be investigated and shall be predicted. The aims are:

• Identification and characterization of degradation mechanisms
• Evaluation of methods and routines for accelerated degradation of the battery components
• Development of a model for state of health analysis and lifetime prognosis

Degradation mechanism will be characterized qualitatively and quantitatively in relation to different parameters such as operation time, charge/discharge behavior, and surrounding conditions. For this, each battery components (membrane, electrode/bipolar plate, electrolyte, sealing) will be studied with different analysis methods. Special interest of the working group Electrochemistry group will be focused on the degradation processes of the vanadium electrolyte. Main task is to develop and establish easy-to-apply and effective online-monitoring methods in order to precisely diagnose the state of charge (SoC) and state of health (SoH) of redox-flow-battery.

Furthermore within the project, methods and routines which allow a targeted and accelerated degradation of the battery components will be developed and established. Finally, a degradation model will be newly developed. This model shall allow prognosis of lifetime and contribute to longer service life of vanadium redox-flow-batteries.