Researchers are working on devolving new technologies to help create large scale storage batteries to store renewable energy. This challenge is one of the last remaining hurdles for the world to get by in order to transition to a fully sustainable planet.
New tools have been created by a team of scientists working at the University of Cambridge in order to help the breakthrough and find more efficient and sustainable ways to store energy in large scale energy storage systems.
The techniques that are being used are based upon the principles that are used in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). These methods can also be used to help find any faults or defects in electrochemical cells or batteries.
The problem to store excess renewable energy has had researchers working on solutions for some time now. With the aim to be able to store excess energy that is produced during particularly windy or sunny periods from the wind farms and solar panels. Then at times when there is little to no wind and not very sunny, the excess energy that has been stored can be used to power the grid.
One of the solutions that researchers have found is using a redox flow battery. This is a storage cell, which can sometimes be as big as a building, which is made up of two tanks containing electrolyte liquid, one positively charged and the other negatively charged. The size of the storage can just be scaled up by increasing the size of the tanks. This technology was the main subject for the research team at Cambridge.
The problem with these batteries is that they degrade too quickly to be used in commercial applications however they are able to store enough renewable electricity to help power towns and cities.
The professor who led the research team, Clare Grey, stated that to make progress in the field it is essential that they are able to work out how the systems work but also what makes them fail.
Normally, companies who make redox flow batteries use vanadium as the electrolyte. However, this is very expensive and toxic, so the researchers used organic materials which are more sustainable and less expensive.
The main problem with using organic materials is that they degrade quicker and therefore is not optimal for a large scale storage use. Scientists have known this for a while; however they did not know the reason to why they degrade so much quicker.
To try and work out why they degrade the researchers used nuclear magnetic resonance to study the batteries similar to how an MRI would work. This allowed the researchers to read the resonance signals from the molecules in the batteries in their normal state and once they had degraded.
This allowed the scientists to have an insight into the different mechanisms of each reaction, including radical formation and electron transfers the differing redox active elements in the tanks.
The findings of the research were that by charging the redox batteries at a lower voltage it would massively decrease the rate of degradation and therefore increase the lifetime of a battery. They also found that changing the structure of the organic molecules can make them degrade at a slower rate.
The group of researchers now hope to further their research in the field by moving onto different types of redox flow batteries and other types of batteries in general.