Institute for Particle Technology (iPAT), TU Braunschweig
Institute of Joining and Welding Technology (ifs), TU Braunschweig
Helmholtz Institute Münster (HI MS)
Münster Electrochemical Energy Technology (MEET)
In order to fulfill the growing demand for lithium ion batteries with even higher energy-densities than they are available today, silicon has been identified as promising high-capacity material for anodes. However, it is well known that silicon has inherent disadvantages challenging the lifetime of lithium ion batteries caused by large volume variations when charging and discharging. This results in an increased formation of SEI and therefore consumption of electrolyte together with according irreversible lithium-losses. The latter will be addressed by the project PräLi, which has set itself the goal of using innovative process technology to increase the quantities of lithium available in the cell to such an extent that the consumption during the use of the cell is compensated. This will make it possible to add silicon in larger quantities to lithium-ion cells, thereby achieving high energy densities with high reliability and a long service life.
The aim of the project consortium is to establish a fully continuous electrochemical process for the prelithiation of electrodes, in which prelithiation is achieved by the reduction of lithium-containing salts in a bath.
In addition, alternative pre-lithiation processes based on the use of metallic lithium as a source are (further) developed. Two production methods are considered, which can also be industrialized as a clocked, semicontinuous process in combination with cost-efficient mini-environments. On the one hand, an electrolytic process with a Li sacrificial electrode for the formation of the SEI is being investigated. On the other hand, a sacrificial layer is applied to the electrode surface using PVD.
All the processes described are evaluated in terms of cell performance and cost-effectiveness.