Revolutionary coolant reduces battery charging time while also increasing life span
The Martin Luther University Halle-Wittenberg has significantly advanced the development of e-mobility: Felix Marske and the working group headed by Prof. Hahn from the Institute for Chemistry have developed a new material whose phase transition from a liquid to a solid makes it suitable both as a coolant and a heat storage material. It is particularly promising for the automotive industry as a coolant and relevant to the construction industry as a heat storage material.
The idea behind the product developed by the scientists in Halle is nothing less than revolutionary. They have been awarded the automotive cluster prize by the 16th IQ Innovationspreis Mitteldeutschland (IQ Innovation Award for Central Germany) for their compound, known as ss-PCM. Felix Marske, a PhD student at the Institute and author of the research paper forming part of his thesis, explains the reason behind their keen interest in the automotive industry: “A sticking point in the development of e-mobility is the charging stations. The big problem with batteries is cooling: we will soon be able to solve this problem more efficiently, meaning we can reduce charging times at the next generation of charging stations.” Until now, the downside of lithium batteries was that they overheated when charged quickly, which in turn reduced their life span and performance.
Trapping the liquid
The research focused on latent heat storage devices that work on the basis of phase change materials (PCMs), which store heat when they change their state of matter. A practical example of this is hand warmers that absorb and store heat when changing from a solid to a liquid state and then release this heat when changing back from a liquid to a solid. Until now there has been a problem with this transition from solid to liquid, however. When melting, the PCM would lose its shape and there was a risk it could leak. This is where the researchers came in. “Our process is innovative because the material is trapped in a porous lattice that liquid cannot escape from,” says Marske. The nanoscopic silicate framework encapsulates the molecules of the shape-stabilizing latent heat storage device in a way that increases the thermal conductivity, ensuring that the heat storage material melts evenly. The lattice’s high capillary strength prevents the PCM from leaking. At the same time, the cooling effect is increased due to the reduced heat generation, meaning batteries charge more quickly while also having a longer life span.
Marske explains that there are four potential ways in which the material could be used in the automotive industry. For example, the battery blocks in electric vehicles could be completely coated in ss-PCM. He goes on to say that automotive companies have already begun planning further development, but that there is so much demand from the industry that they are currently having trouble keeping up. But ss-PCM is by no means promising only for the automotive industry. Marske maintains that it could also be used in phone batteries, night storage heaters, solar thermal technology and housing. It could also be possible to fill roof shingles and concrete walls with the material. Crucially, ss-PCM can store up to 14 times more heat than conventional construction materials, meaning worldwide energy consumption for indoor heating could reduce massively. If electricity is priced at 28 cents per kWh, a 2-cm thick ss-PCM wall with an area of 3.6m² could save around €154 a year. That means that you could recoup the cost of a €170 ss-PCM wall in just 13 months! At the same time, the material would also prevent rooms from becoming too warm in summer.
Latent heat storage devices in the form of microscopic capsules are already being built into plaster and concrete walls. However, in order to guarantee that the construction material remains stable, only 15% of the PCM can be built into it. “Our material allows you to fill up to 90%,” says Marske. This would greatly increase energy efficiency. At the end of last year, the scientists were awarded second place in the “Most Innovative Basic Research Project” category in the Hugo Junkers Prize (the highest-value award issued by the state of Saxony-Anhalt) in recognition of their development.
There is currently so much interest in ss-PCM from industry that Marske can barely keep up. He says that he has applied for a patent for the material and that they are currently trying to get accepted onto the EXIST research transfer program in order to gain more funding and human resources and to create a spin-off. “We are currently setting up a supply chain,” he says, “and are in talks with one company that produces the material. For just a small surcharge, we can manufacture the product in a way that is 100% ecological and can expand our product portfolio to include different ss-PCMs.”
The development of ss-PCM is another milestone in Saxony-Anhalt’s journey toward becoming a leading light in production processes for the vehicle of the future. The state has always had a part to play in automotive development. But that’s not all: as a location for the chemistry and plastics industries going back 100 years, it also has the necessary materials to make that happen.