How the cell is created: Production steps for sample manufacturing at the CMCC
Cell manufacturing begins with electrode production. Here the base material, comprising, for example, graphite for the anode and nickel oxides for the cathode, with binders and solvents, is metered and mixed in a precisely measured ratio. This creates the so-called “slurry” - which means wafer-thin metal foils are coated and then compressed after drying. In technical jargon, this is referred to as “calendering”. The highest level of precision is required: The foil is just a few micrometres thick - in other words, thinner than the threads of a spider web, while the coating is in the micrometre range. During cell assembly, the coated foils, referred to as calendered electrodes, are wound into so-called “jelly rolls” using the separator and inserted into the cell housing. The cells are filled with electrolyte, then charged for the first time and finally checked for functionality and quality.
Sixth-generation BMW battery technology: New cell format and enhanced cell chemistry
The battery cell is responsible for electric vehicles’ core properties: range, driving performance and charging time. With the new BMW round cell specially designed for the electric architecture of the Neue Klasse models, it will be possible to significantly increase the range of the top model by up to 30 percent (according to WLTP).
The new BMW round cells come with a standard diameter of 46 millimetres and two different heights of 95 millimetres and 120 millimetres. Compared to the prismatic cells of the fifth BMW battery cell generation, the nickel content of the sixth-generation BMW round cells will be higher on the cathode side, while the cobalt content will be reduced. On the anode side, the silicon content will be increased. As a result, the cell’s volumetric energy density will improve by more than 20 percent.
Battery, drive train and charging technology in the Neue Klasse will have a higher voltage of 800 volts. Among other things, this will optimise how energy is supplied to direct current high-power charging stations, which can achieve a much higher charging capacity with a current of up to 500 amperes - thus reducing the time it takes to charge from ten to 80 percent by up to 30 percent.
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Video Timeline
0:00 - BMW Battery Cell Pilot Production (Plant Parsdorf)
6:07 - BMW Battery Modules Production (Plant Leipzig)