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Focus on Innovation: Silicon Nonwoven Anodes – The Key to the Next Generation of High-Performance Lithium-Ion Batterie

We are pleased to announce the launch of an exciting new project at BlitzLab, focusing on the development of silicon nonwoven anodes (SiVlies) as a key component of high-capacity lithium-ion batteries (LIBs). This innovative research, realized in collaboration with the Fraunhofer Institute for Ceramic Technologies and Systems (IKTS), aims to push the boundaries of energy storage technology and make a significant contribution to the ongoing energy transition. 

 

The project is entitled: Silicon fleece anodes as part of a lithium-ion battery (SiVlies) (project duration: June 13, 2024 – August 31, 2027) 

Project Background: 

Lithium-ion batteries are crucial for the future of energy storage, offering a highly efficient solution essential for sustainable energy systems. Silicon as an anode material offers a significant advantage over traditional graphite materials, with a theoretically ten times higher capacity. However, the application of silicon anodes is challenged by a significant volume expansion (up to 300%) during the lithium reaction, leading to rapid material degradation and capacity loss. 

The goal of this project is to develop novel high-capacity silicon anodes with an anode capacity exceeding 5 mAh/cm² for LIBs with energy densities over 300 Wh/kg. The production process will be based on cost-efficient printing and infiltration techniques of silicon powder into conductive nonwoven collectors, which offer a three-dimensional, open-pore, and mechanically flexible structure at low weight. 

SEM image of an older generation silicon fleece anode with applied Si-PVD layer, whereby the fleece material was not completely coated in the porous 3D structure.
Representation of the energy density of NMC811/graphite cells as a function of the surface capacity of the anode. [1] with marking of the project target area based on a theoretical estimate of the expected capacity of the Si fleece anodes. [1] Yang Zhang “Solvent-Free Electrode Fabrication Based on Polytetrafluoroethylene Fibrillation for Lithium-ion Batteries”, Thesis, University of Stavanger, Norway, 2022.

Our Approach: 

With Dr. Christoph Folgner as project leader, BlitzLab will bring extensive expertise in thin film deposition, thermal material treatment including photonic sintering methods such as Flash Lamp Annealing (FLA), and material modification using ion irradiation to the following key areas: 

  1. Advanced Silicon Coating: Together with our project partner FhG-IKTS, we will further develop the silicon coating processes from the liquid phase for flexible and porous fleece substrates.
  2. Innovative Sintering Techniques: By utilizing FLA techniques, we will efficiently sinter the deposited silicon layers to ensure high stability and performance of the silicon nonwoven anodes.
  3. Comprehensive Material Characterization: The manufactured material composites will be thoroughly analyzed electrochemically and microstructurally to assess their suitability as LIB anodes.

Funding: 

This project is part of the funding directive “Energy and Climate EuK/2023 – Module I Application-Oriented Energy and Climate Research,” with a thematic focus on “Storage Technologies.” It is funded by the Sächsische Aufbaubank – Förderbank (SAB) and co-financed by the European Union. 

 

Funding code: 10072535

Example image of a nonwoven structure that is metallized in the project, homogeneously coated with silicon as anode material using printing techniques and then functionalized using photonic sintering processes (flash lamp, laser).

The Path Forward: 

With this exciting project, we build on previous successful initiatives like the SAB SiNergy project (FKZ 100256790). By exploring the potential of recycled silicon from the wafer and photovoltaic industries, we strive for sustainable and cost-efficient solutions for high-capacity energy storage. 

Stay tuned for updates as we explore new possibilities in the field of printed electronics and energy storage technologies. Follow us on LinkedIn to stay informed. 

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