The manufacture of electrodes is currently an extraordinarily expensive, inefficient and even questionable process from an environmental point of view. But this will change.
We cannot deny that the commitment to decarbonisation promoted by administrations, companies and organizations from all over the world requires a point of hypocrisy.
But the truth is that the current state of the technologies associated with electric mobility, the production of renewable energy and even the storage of this type of energy does not allow, for the time being, a environmentally sustainable process from start to finish.
“When we tested them on batteries, they seem to work just as well as those made with solvents.”
Thousands of scientists and researchers from all over the world work to achieve this and advances like the one we bring you today are aimed at it.
“It is a new approach for the manufacture of battery electrodes”, reveals researcher Tor Olav Sunde from SINTEF, one of the most powerful independent development organizations in Europe. “This dry battery system may be Elon Musk’s wet dream,” he adds.
Sunde speaks of a process similar to the one in 2019 it led Tesla to pay almost 200 million euros for the American company Maxwell Technologies. Company that he recently sold when he got what he wanted from it: to learn about dry electrode manufacturing.
But what is so special about this technique?
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The battery electrodes
As we have already told you on other occasions, the cathode and the anode of the batteries are electrodes that allow the transfer of electrons with the help of the electrolyte.
But the manufacturing process of these electrodes, something like the heart of a battery, is complex and very expensive for several reasons.
On the one hand, the manufacture of electrodes consumes a lot of energy and requires a lot of space. In addition, the process is also dangerous for both people and the environment.
“The material of the active electrode, through which the ions enter and leave, must be mixed with additives”explains Tor Olav Sunde. “This is necessary to ensure that the electrodes stick together and conduct electricity.”
To mix the active chemical materials with the additives, the mixture must be stirred with a solvent to produce a moist mass, which is then coated onto the metal foil. Before assembling the battery, the solvent must be removed, and this is done by drying the electrode.
“This process is very energy intensive, and more than a third of the energy needed to make a battery can be devoted to this drying process,” says Sunde.
Said drying process requires not only a huge amount of energy, but also a lot of space to house the large ovens used in the process (several tens of meters long).
“The process is also time consuming because the electrode material needs to dry in a uniform and controlled manner to prevent cracking. Also, commonly used solvents can be very unpleasant,” adds Sunde. “They are toxic to people and dangerous to the natural environment”.
“You need massive systems and equipment to recover them and prevent them from downloading. Massive amounts of HSE equipment must be installed as part of the process, making it even more complex and costly,” Sunde continues.
Dry batteries and electrodes
The solution to this problem is manufacture dry electrodes, without the need to use solvents. But this is a process that has been investigated for years and it is not easy to find the solution.
The most difficult aspect is making the electrode coating thin. This is what SINTEF is investigating now. You can’t just mix a bunch of raw stuff together and expect things to work out.
“We simply carry out the mixing process without using solvents. The active material and additives are mixed dry. We’ve tried several different ways of doing this and have learned a lot about what works and what doesn’t,” says Sunde.
“We also need heat and pressure. We have to work with temperature and pressure so that the electrode has the correct properties. The electrodes we have made so far look very good,” continues Sunde. “When we tested them on batteries, they seem to work just as well as those made with solvents”.
The success of this technique brings with it an enormous energy and economic savings. Although there is still a long way to go before reaching the final goal, which is to make large battery plants less energy demanding and more ecological.
In the meantime, SINTEF has achieved small-scale dry processing in the laboratory. However, more work is needed before the process can be industrialized, both in terms of quality and scale of production.
“But we have the first results and we have shown that the process works”concludes Tor Olav Sunde.
Source: SINTEF