Publication date: 27 October 2017

DeadlineModel: single-stage

Planned opening date: 24 January 2019

Deadline: 25 April 2019 17:00:00

Topic Description

Specific Challenge:

Redox flow batteries (RFB) are considered prime candidates for grid-scale stationary energy storage due to their ability to store large amounts of electrical energy for extended periods and release it quickly when needed. Their extended lifetime and reasonable efficiency are additional benefits. The redox couples and the electrolytes are the most important component in redox flow batteries, as they largely determine system energy density and cost. Currently used RFB rely on metal-based redox pairs that are non-indigenous to Europe, and can be highly corrosive and sometimes toxic. In addition, these systems are mostly water-based, which can potentially result in water electrolysis at high voltage, and membrane cross-over. Mining and extraction of metals can have substantial social and environmental impact. These issues all affect the cell’s efficiency, cost, safety and sustainability. The challenge is to identify suitable redox pairs and electrolyte chemistries for low-cost, high-efficiency and sustainable stationary RFB systems that are optimised in terms of redox potential, electrochemical reaction reversibility, chemical stability, solubility and material availability. Since extensive laboratory testing is both time consuming and costly, modelling and simulation is needed to prioritise promising redox species for further analysis and testing. This challenge is in line with the identified priorities in the context of the SET-Plan.


The objective is to develop mathematical models for numerical simulation and high-volume pre-selection of multi-species electrolyte flow and electrochemistry. Models should allow the characterisation of new chemicals and designs, the related charge, mass and heat transport mechanisms, identifying cell-limiting mechanisms, forecasting cell performance and optimising the design and scale-up. Of particular interest are performances in terms of cell voltage, energy and power density, reliability and cost.

The simulation models should be validated with experimental examples from known chemistries and representative prototypes, and show how new chemistries can be explored.

The Commission considers that proposals requesting a contribution from the EU of up to EUR 2 million would allow this specific challenge to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts.

Expected Impact:

The proposed action should allow to significantly enhance research and engineering processes, and accelerating the search for new non-rare and non-toxic redox couples and electrolytes. These would allow reducing production costs in materials and component development, contributing to optimising the design and performance of full-scale low-cost and environmentally sustainable RFB systems for balancing intermittent renewables on a grid scale. Project results should in the medium to long-term term contribute to reach the targets set in the SET Plan and stimulate investment in the low-carbon energy sector, with the long term aim to boost innovation-driven growth and industrial competitiveness in stationary electrical energy storage.

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