PEM To Scale Up Method For Liquid Coating Of Lithium Metal Anodes

The Chair of Production Engineering of E-Mobility Components (PEM) of RWTH Aachen University is developing an innovative melt coating process for the production of ultra-thin lithium metal anodes as part of the EXIST research transfer project “LIMA”. In contrast to the cost-intensive state of the art, which is limited in terms of layer thickness and is difficult to scale, the new method enables inexpensive and industrially viable production of lithium foils with optimized electrochemical properties.

The core of the technology is the controlled application of liquid lithium to substrate foil. Ultra-thin lithium metal anodes are considered key components for next-generation batteries – especially solid-state batteries – as they allow for significantly higher energy density. This is essential for increasing the range of electric vehicles and enabling applications that are difficult to electrify, such as in aviation and shipping. Meanwhile, conventional lithium-ion batteries with graphite anodes are gradually reaching their physical limits. “The new technology has the potential to create a European independent production capacity for lithium metal anodes,” says PEM Director Professor Achim Kampker.

PEM spin-off “LIMA”
The intention of the EXIST program is to spin off a company in order to further develop research results with start-up potential. The specific goal is to clarify issues relating to the implementation of scientific results in technical products and processes, to develop the corresponding business idea into a business plan, and to prepare for the start-up of the company. The “LIMA” team consists of Aachen-based researchers Gerrit Bockey, Jonas Gorsch, Junia Dietert, and Hendrik Minis Pai.

Avoiding previously high scrap rates
The “LIMA” process allows for significant lithium savings, depending on the initial thickness of the foils used. In the classic procedure, lithium foils are produced by using complex, multi-stage rolling processes in which 100-micrometer-thick foils are rolled out to 30 to 70 micrometers and then laminated onto copper foil. However, since many applications only require 20 to 25 micrometers, the current process results in considerable material loss.

Precise control of layer thickness
However, the “LIMA” method does not require lamination. Instead, a lithium ingot is melted down, which brings further cost advantages. “In contrast to existing processes, which fail due to the difficult workability of lithium or do not achieve the necessary layer thickness, we make targeted use of the challenging material properties,” says PEM expert Gerrit Bockey, designated co-CEO of the “LIMA” spin-off company. The technology was developed as part of the RWTH researcher’s dissertation. In addition to material savings, the concept offers greater process control and flexibility. The layer thickness can be precisely controlled – without the mechanical post-processing that was previously necessary.