Thin Film Deposition

Research into lithium and post-lithium technologies grows significantly and there is a pressing need for improvements in service life, charging times, energy density and safety.

Thin film processes offer innovative approaches to enhance and optimize lithium-ion cells throughout their entire system structure. This includes diffusion barrier coatings, anti-corrosion coatings and complex chemical coatings for active cathode materials. Additionally, metallization of thin polymer films can replace metal foils for current conductors and metallic lithium deposition can be used for pre-lithiation or as a metallic thin film electrode.

Our research also extends to future energy storage technologies beyond lithium. Our vision is to develop low-cost, high-performance batteries that promote electromobility and support global energy transmission. By advancing thin film processes, we aim to facilitate the cost-effective production of high-performance battery components, contributing to the evolution of energy storage technologies.

Metallized polymer films as current collectors offer a promising solution to enhance battery performance. These films replace traditional metal foils, achieving a total thickness of under 10 µm, with a base substrate less than 8 µm and metal thickness over 1 µm. Produced via a roll-to-roll process, they are coated with aluminum or copper using electron beam evaporation or magnetron sputtering. The result is a lightweight, thin design that improves both volumetric and gravimetric energy density while enhancing the safety of battery cells.

Pure silicon anodes in lithium-ion cells offer a significant boost in volumetric energy density. To achieve high cycle stability, porous nodular structures are essential to accommodate volume expansion. The roll-to-roll process, utilizing magnetron sputtering and an electron beam process in development, allows for efficient production. These porous silicon layers provide high charge capacity and enhanced cycle stability for advanced lithium-ion batteries.

Lithium layer production has traditionally involved rolling processes requiring lubricants, introducing contaminants. Advancements in thin film deposition allow for pure lithium thin films of 1 to 20 µm to be created in vacuum, ensuring high purity and reproducibility. Research focuses on optimizing layer thickness and morphology, de-veloping passivation layers, and pre-lithiating anodes. Fraunhofer FEP methods enable high deposition rates, offering flexibility in anode thickness and layer composi-tion, enhancing performance in PVD-based manufacturing processes.