2022-11-02 | Corporate
About 20 % of greenhouse gas emissions in the European Union are caused by traffic at the moment. If you occupy yourself with this issue, you will not get past one subject: batteries. For decades, they have been indispensable for radios, toothbrushes, or phones, and in the last years we even changed to electric energy on larger scales, for example, with cars. Electric vehicles are in trend. And although they bring advantages, sometimes there is still a little bit of fear left: What if the car battery suddenly explodes?
“In principle, it is possible. Incorrect exposure can theoretically lead to a burning battery, even a car battery,” says Christopher Giehl, Training & Communication Manager in the field of rheometry at Anton Paar and expert for batteries. Electric vehicles are usually equipped with a lithiumion battery. This battery consists – like all batteries – of a positive (anode) and a negative (cathode) loaded side. In between is a separator and an electrolyte solution, which provides the charging transport of lithiumions. If the two sides “touch” each other without an electrolyte solution and separator, or if the battery (dis-)charges too fast, overheating occurs, and the battery may explode. For a car battery, this might be possible during an accident – for example when the separator gets teared up or pierced.
This is where Anton Paar rheometers like the MCR 92 or 702e MultiDrive come into play. They are used for three different analyses in the field of batteries. “First: The flow behavior of so-called ‘slurries’ is analyzed. Slurries are applicated onto the current collector in liquid state, dried, pressed, and form anode or cathode. For the mixing, transport, and the coating process onto the current collector, the rheological characteristics of slurries are highly important. Second: The stretching characteristics of the separator can be analyzed; it needs to be very stretchy, not tearing easily, and be also stable in high temperatures and humidities. And third: We are analyzing the electrolyte solution, the liquid between anode and cathode. It must be easy to fill in, but ideally be shear-thickening, meaning it will stiffen up under sudden strong pressure like a car accident. Otherwise, the anode and cathode would touch, which would cause a short circuit and could result in a fire or explosion,” says Christopher Giehl.