Newsletter Edition 12/2021

In our second edition we briefly review the first half of the project and present our activities concerning the higher scales, such as a microCT scan of a graphite felt, our approach to numerical stack & system simulations and, finally, the total cost analysis for two lab-scale systems based on different electrolytes.

Read the full version here

SONAR successfully completes phase I of the project

November 2021

Flow battery test cell at the Fraunhofer ICT for simulation results validation

After a project duration of 18 months, the SONAR project was evaluated by INEA, the project executive agency of the European Commission (EC), as planned. Within the framework of a report and a special review meeting, the EC project officers and an external reviewer were presented with the results of the project so far. The main focus was on the status of the development of the high-throughput screening method to search for new organic active materials, as well as the sub-aspects based on atomistic, Kinetic Monte Carlo (meso-scale) and continuum modelling and simulation. SONAR successfully passed the peer review and secured funding for the next phase, which will also focus on the stack, system, costs and behavior in the network.

ZHAW publishes open source 0D cell model and program to calculate flow battery characteristics

November 11, 2021

Screenshot of GUI for interactive manipulation

As part of the EU-Australian SONAR project, the University of Applied Sciences Zurich, Switzerland, has published an open-source program for calculating the characteristics of organic redox flow batteries. The program is based on the popular mathematical application "Mathematica" and allows the evaluation of polarization curves as predicted by the 0D-U-I-SoC model for user-specified model parameters. Especially for small and medium current densities, which are not in the range of mass transport limitations, the results of the software are very accurate and can be adapted to the specific battery chemistry by adjusting the input parameters. This allows statements to be made about the expected voltages and currents, as well as capacities and energy densities at different states of charge for an almost infinite number of battery chemistries.
In the SONAR project, ZHAW is responsible for the development of optimized cell models for automated high-throughput screening of organic active materials for future, novel redox-flow batteries to store renewable energy.
The open source simulation software and a user discussion forum are available on GitHub

Flow battery systems and their future in stationary energy storage – Policy brief

November 2, 2021

On 9th July 2021, at the Summer Symposium of the International Flow Battery Forum, the FLORES Network of Flow-Battery Research Initiatives held a workshop to identify research
needs, barriers, potential markets and impacts of flow batteries. The outcomes, including resulting policy recommendations, are provided here.

Work on system modelling and cost analysis started in SONAR

September 2021

Current distribution of the 2D single cell of VRFB under different constant flow rates, left) flowrate = 30 mL/min right) flow rate = 5 mL/min

The University of New South Wales and Fraunhofer ICT started their work on stack and system modeling and cost analysis for organic flow batteries, with one new PhD student at each of the two institutions. The system modeling will be carried out using a multiphysics approach, where first the hydraulic, electrochemical and thermal properties of a single cell, then a stack and finally a whole flow battery system are modeled and simulated. The results will lead to a better understanding of systems and thus to cheaper and more reliable systems, and also form the basis for the cost analysis.

In the cost analysis of flow battery systems, Fraunhofer ICT is concerned with linking technical parameters with costs using mathematical functions. The objective is to map a cost structure for the investment costs of flow batteries in order to determine cost proportions and for sensitivity analyses. Based on the calculated costs, batteries can be compared on the basis of investment costs (CAPEX). A much more substantiated comparison is possible based on levelized cost of storage (LCOS), where lifetime costs are calculated in relation to energy throughput. In the future, it will be possible to calculate the LCOS of a large number of new organic flow battery chemistries automatically, in order to be able to develop low-cost candidates for new, safe and environmentally friendly organic flow batteries for the storage of renewable energy.

New Paper about predicting pH-dependent Redox Potentials

June 29, 2021

In the Special Issue Computational Design and Modelling of Organic Materials for Energy Applications of Molecules Rocco Fornari and Piotr de Silva present a computational protocol combining DFT and Cheminformatics for pH-Dependent Redox Potentials:

Animation of RFB discharge simulation with constant inlet concentration

June, 2021

© Amadeus Wolf, KIT, Germany

The image shows a pore scale 2D slice that is coloured according to the [4-OH-TEMPO]+ concentration in mol/m³.  Wholes represent cylindrical electrode fibres and arrows represent the steady-state velocity profile in m/s with Reynolds-Number of 0.0005. Note the depletion of [4-OH-TEMPO]+  at the electrode-electrolyte interface over time: The concentration profile evolves according to the velocity field and reaches a steady state after several milliseconds.

New paper on a graph convolutional network for rapid prescreening of organic compounds

May 31, 2021

A paper on machine learning for predicting formal potentials appears in a Special Collection on Artificial Intelligence in Electrochemical Energy Storage in Batteries & Supercaps by Laura Berg et al:

Interview of Maria Skyllas-Kazacos by QEM’s managing director Gavin Loyden

May 27, 2021

Find the full interview here.

Flow Batteries Europe: Long-Term Strategy for Flow Battery Technology

April 28, 2021

In order to create more awareness for RFB technology, and to combine the interests of industry and research in the field, the association “Flow Batteries Europe” was founded on 28.04.2021. Flow Batteries Europe will try to increase knowledge about redox flow batteries through dissemination and policy briefing.

The German/Australian Alliance for Electrochemical Technologies for Renewable Energy Storage (CENELEST) is a founding member of Flow Batteries Europe. CENELEST member and FlowCamp coordinator Dr. Peter Fischer (Fraunhofer ICT) was elected to the Executive Board and will represent Fraunhofer ICT (Germany) and the University of New South Wales (Australia) in Flow Batteries Europe.

For more information about the association, please contact Peter Fischer or visit the website.