Integrated Computational Materials, Process and Product Engineering – IC-MPPE 2022

Since the large automotive companies go ahead with the electrification of the power train, also the demand for more powerful electrochemical energy storage systems is growing. However not only the automotive industry requires more powerful accumulators. In the area of mobile consumer electronics, the proceedings of the last years are compensated by the rising energy demand of the devices. In addition, the fast charging requirements for some consumer electronics products are approaching the same level on the same level compared to the automotive industry.

The specific energy of a lithium ion battery is given by the product of specific charge - more precisely the lithium storage ability per mass and the voltage difference of negative and positive electrode. As far as the negative electrode is concerned lithium and lithium compounds already represent the most reductive species of the electrochemical series. However carbonaceous materials that are used in state of the art lithium ion batteries are only able to store up to 1 lithium ion per 6 carbon atoms in the case of fully crystalline graphite, which results in a quite low charge density of 759 Ah∙l-1. The application of metals or semi metalloids, which are able to store lithium under formation of an intermetallic phase represents a very promising alternative, whereas especially silicon has turned out as a very promising material that would offer - at least theoretically – more than 3 times higher charge densities. It is well known that the high charge density comes along with several challenges like structural stability, instability of the SEI layer as well as special requirements for the cell design. Within this talk advantages and disadvantages of different silicon based material concepts in combination with their requirements for processing and cell design will be discussed.