Lab Characterization and Post-Mortem Analysis

We analyze battery components using modern analytical methods and characterization equipment to support our customers in process and product development. Our services are aimed at companies and research institutes that develop and manufacture batteries and electrical storage systems.

One of our core competencies is the performance of post-mortem analysis of battery cells. For example, by analyzing cell components, we identify the causes of performance problems or failures. These studies are critical to improving the safety and lifetime of battery cells.

Our laboratories are equipped with a wide range of analytical methods that allow us to perform detailed and precise investigations. In addition, our interdisciplinary team has many years of experience in battery material characterization.

Our R&D-Services in the »Lab Characterization and Post-Mortem Analysis« Include:

• Characterization of Aqueous and Organic Electrolytes
• Investigations of Electrodes and their Components
• Soft X-Ray Emission Spectroscopy for the Analysis of Lithium
• Post-Mortem Analysis of Batteries and their Components
• Mechanical Characterization of Battery Materials

For the investigation of electrolytes, different analytical methods are available at Fraunhofer ISE:

• Confocal Raman spectroscopy can be used to analyze the molecular structure and identify reaction products in the electrolyte
• FT-IR spectroscopy can be used to analyze chemical bonds and functional groups as well as the presence of water
• Gas chromatography-mass spectrometry (GC-MS) enables the separation and identification of organic components
• Inductively coupled plasma-OES analysis quantifies metal ions
• Conductivity measurements evaluate the ionic conductivity of the electrolyte to determine electrochemical performance
• Electrochemical methods such as CV, PEIS and galvanostatic cyclization

These methods provide comprehensive information for the optimization and improvement of electrolytes for battery cells.

Various analytical methods are available at Fraunhofer ISE to address issues related to electrodes and their components (active material, binder and conductive additive). Since battery materials are often sensitive to water and oxygen, the analysis can be performed either under inert gas or in a dry room:

• Scanning electron microscope (SEM) equipped with detectors for energy dispersive X‑ray spectroscopy (EDX), electron backscatter diffraction (EBSD), and soft X-ray emission spectroscopy (SXES) to analyze surface morphology and composition
• X-ray diffraction (XRD) to determine the crystal structure
• We also use the following methods to investigate the chemical composition of materials:
  • X-ray photoelectron spectroscopy (XPS)
  • ICP-OES analysis
  • Elemental analysis
  • Confocal Raman and FT-IR spectroscopy
• BET analysis and mercury porosimetry for surface and pore size determination

Our scanning electrode microscope (SEM) is equipped with a detector for soft X‑ray emission spectrometry (SXES), which is suitable for analyzing light elements - such as lithium - with high energy resolution. For lithium, different chemical states can be detected in silicon anodes due to different states of charge (SOC). In addition, the SXES detector is also suitable for the analysis of lithium metal for potential impurities and for the detection of lithium plating on electrodes.

Post-mortem analysis of battery components is critical to understanding degradation mechanisms and performance degradation within battery cells. Prior to opening the cell, CT scans can provide information about possible defects within the cell.

Once the battery cell is opened, it is disassembled into its individual components: Anode, Cathode, Separator and Electrolyte. Optical techniques such as scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) or X-ray diffraction (XRD) can be used to analyze structural and chemical changes in the electrodes and separator.

Electrolyte analysis, for example to identify degradation products, can be performed using ICP-OES or GC-MS analysis. The aim is to identify the causes of capacity loss, material degradation or electrochemical malfunctions of the battery cells.

Mechanical characterizations are key in battery production and upscaling in order to produce long-lasting and safe batteries. Thanks to our material testing machine set up in the dry room, we are able to perform the following tests under real process conditions and also in accordance with standards:

• Tensile test to determine tensile properties in continuous processes such as current collector, separator and pouch films
• Compression test to determine both the compression properties of various battery materials and the volume expansion of battery cells
• Bending test to determine bending properties with regard to continuous processes that require deflections
• Peel and forehead pull-off test to determine adhesion and cohesion properties between current collector foils and electrode coatings, pouch films and laminates or to characterize welded joints
• Needle puncture test to determine the puncture resistance of separators and housing material
• Friction test to determine friction coefficients or abrasion properties between electrodes, rollers, rollers and grippers