SiGgI

SiGgI – Silicon Graphite goes Industry

Sponsor: BMBF

Contact persons : Jannes Müller

Summary of the overall project:

The research project “SiGgI – Silicon Graphite goes Industry” is funded by the German Federal Ministry of Education and Research (BMBF) as part of the program “From material to innovation”.
The project addresses the use of silicon as anode material to increase the energy density of lithium-ion batteries. Silicon is characterized by a very high specific capacity and is therefore ideally suited for high-energy applications. However, the volumetric expansion during lithiation poses a major challenge with regard to the stability of the electrode, making its industrial use more difficult. For this reason, the SiGgI project investigates the scalable production of silicon-carbon composite materials (Si/C composites), as well as the continuous production of electrodes. The focus of the project is mainly on material development, which includes on the one hand the production of silicon nanoparticles by comminution in stirred media mills and their stabilization, and on the other hand the production of composites. Furthermore, the scalable production of composite electrodes with innovative dispersing (stirred media mill, extruder), coating (slot die) and drying (infrared-drying) concepts is evaluated. With a newly developed automated test cell production, the electrochemical performance of the composite electrodes is analysed in a highly reproducible manner as a function of material and process parameters. The design of a system for automatic data acquisition, storage, processing and evaluation (data mining) enables the identification and analysis of dependencies between material properties and process steps.

Goals and tasks of iPAT

• Preparation and stabilization of silicon nanoparticles using stirred media mills and analysis of formulation parameters
• Delamination of graphite to graphene
• Development of a process for silicon-carbon composites
• Scalable electrode production (laboratory to pilot scale
• Evaluation of different process routes for electrode production by innovative dispersion and coating concepts
• Construction of multilayer pouch cells with subsequent safety testing
• Evaluation of the processes at micro level during cycling by means of dilatometry measurements
• Production of silicon nanoparticles
• Silicon-graphite-composite production
• Mecanical and structural stability of Si@Gr composites
• Production of Si@Gr-anodes and high energy cathodes
• Electrochemical characterization of Si@Gr anodes

Fig.1: Process steps in project SiGgI.

Project partners
EL-Cell GmbH (Hamburg), Technologiezentrum Elektromobilität der Volkswagen AG (Isenbüttel), Custom Cells Itzehoe GmbH (Itzehoe), Sili Technolgies GmbH (Warmensteinach), M. Braun Inertgas-Systeme GmbH (Garching), Battery LabFactory Braunschweig (Institut für Werkzeugmaschinen und Fertigungstechnik, Institut für Füge- und Schweißtechnik)