The Battery Experts video series, with Anthony Chalou from Anton Paar, explores dynamic mechanical analysis to investigate and optimize the mechanical properties of films used during battery cell production.
Separators and current collectors undergo significant tension and torsion forces during lithium-ion battery production, and these forces can potentially stretch or tear the materials.
In this video, Anthony examines how a dynamic mechanical analyzer (DMA) can measure the structural properties of these films and determine the forces that they can withstand before breaking or tearing.
Common DMA test methods include tension, torsion, compression, shear, three-point bending, and cantilever. Other DMA measurements include the use of:
- Amplitude sweep to determine the linear viscoelastic region by increasing the oscillation amplitude
- Frequency sweep to investigate a material's behavior at increasing oscillation frequencies
- Humidity sweep to study a material's behavior at different humidity levels
- Time sweep to investigate a material's behavior at constant conditions over time
- Temperature ramp to determine a material’s potential for phase transition at increasing temperatures
DMA instruments can also be used for tensile tests and thermal mechanical analysis, where the thermal expansion potential of a sample needs to be determined.
In this video, Anthony outlines an example investigation using a temperature ramp in tension on a polymer separator material and a tensile test on a current collector material.
He details the parameters and methods used in these evaluations, including appropriate software settings and sample holders. He also looks at the useful data types that can be acquired via these tests.
For example, using the temperature ramp method, the linear viscoelastic range of the material, the glass transition temperature, and the storage modulus over the temperature range can be determined —the latter of which can be related to the Young's modulus.
Anthony outlines how the tensile test method can generate a stress-versus-strain diagram when testing at a constant temperature in the example presented.
The use of a dynamic mechanical analyzer enables a useful assessment of the mechanical properties of films used in battery cell production. Data acquired via these investigations is essential in properly optimizing various steps during manufacturing.
The Battery Experts: The Role of DMA in Battery Cell Production | Anton Paar
Video Credit: Anton Paar GmbH
This information has been sourced, reviewed and adapted from materials provided by Anton Paar GmbH.
For more information on this source, please visit Anton Paar GmbH.