Society’s increasing use of electric vehicles, grid energy storage and portable consumer electronics is driving researchers to improve battery and energy storage products at a breakneck pace. In order to improve energy storage, the research community must unravel the mysteries of material degradation in these bleeding-edge technically advanced materials.
Evaluation of batteries and battery components requires a variety of analytical methods that study bulk materials and component surfaces at various scales. An entire suite of analytical solutions is required in these investigations, many of which are described in this application overview. Are you facing a research challenge that one of these solutions can solve?
Analyzing morphology: Imaging techniques such as Raman, microCT, and electron microscopy are mainly used to study the 2D and 3D morphology of battery components at different stages in the lifecycle. These techniques cover the full length scale from the cell level with Raman and microCT down to the atomic scale with TEM. Electron microscopy is the basis for many of the solutions used to study morphology, including: SEM, microCT, Plasma FIB, FIBSEM, and TEM.
Analyzing cyclic degradation: 3D imaging provides complete geometric evolution of the cathode microstructure upon cycling. Geometric parameters such as volume fraction, surface area, particle size distribution and tortuosity are typically assessed using a combination of microCT and FIB–SEM techniques.
Analyzing structure: Spectroscopy, NMR, X-ray diffraction and mass spectrometry are key to study the evolution of structural changes and the defect formation in battery electrodes. These techniques permit the analysis of electrode materials as they change during the redox reactions; and give information on both crystalline and amorphous phases. For example, in situ FTIR can provide real-time information about the chemical nature of adsorbates and solution species as well as intermediate/product species involved in the electrochemical reactions.
Analyzing charge states: Local differences in Raman spectral changes can create a state-of-charge (SOC) distribution map showing the composite electrode. The composition of the Solid Electrolyte Interface (SEI) is commonly studied with ex situ XPS and in situ FTIR and Raman spectroscopy to monitor the SEI formation. For example, Raman is a useful technique in developing alternatives to lithium cobalt oxide cathodes, such as manganese spinel material. For studying the all-important interfaces in a solid oxide fuel cell, as a surface technique, XPS is essential for understanding the interfaces between electrolytes and electrodes.
Analyzing production parameters: The rheometry and viscometry systems measure the dispersiveness and coating capability of battery materials in the electrode slurry. Torque rheometers deliver information about melting behavior, influence of additives on processability and temperature or shear stability; all critical parameters for the production of polymer separators.