Summary and action points for Working Group 4
We have discussed the potential of using organic redox species in flow batteries. We have agreed that the potential is great in terms of price but there are still some challenges that need to be solved. For instance, the water solubility, chemical stability and the limited voltage those quinones can give. With respect to water solubility, new organic molecules are to be synthesized, that form salts in water based electrolytes.
Another approach is to use different solvents, but this will:
- increase the price and
- increase the electrical resistance of the electrolyte.
With respect to chemical stability the problem is not in the anthraquinones side, as that one is chemically robust, but in the hydroquinone side, that is not stable during charging/discharging. A work is currently being done at AU to address this problem.
The maximum voltage with quinones in water is probably around 0.9 V and not more. This is not a significant problem as long as the price of these commodities is low. We have also discussed the pumps, cell designs for flow batteries and targeted area resistances of flow batteries.
A short description of next step
There is a possible cooperation between computational part at DTU and our group at AU. It was only three of us speaking so there was no critical mass but we do agree we should stay in contact.
Key person: Emil Drazevic, AU Engineering
Peter Bjerre Jensen, DTU
Kristian Bastholm Knudsen, DTU
Heine Hansen, DTU
Christian Henriksen, SDU