Microscopes play a key role in improving lithium ion battery technology, as many performance and safety-related effects can be observed and fine-tuned at microscopic and nanoscopic length scales. However, these effects often become apparent only after multiple cycles of charge and discharge. Studies of the microstructure over time are thus critical to understanding the longitudinal dynamics of battery performance.
The volatile nature of battery materials makes x-ray an attractive imaging mode for non-destructive analysis. Many X-ray CT systems claim sub-micron resolution, but this is only possible when the sample is prepared very carefully — this usually means de-packaging (typically in a glove-box), washing away electrolyte, and cutting the sample down to a very small piece.
ZEISS X-ray microscopy with Resolution at a Distance (RaaD) allows you to perform non-destructive, high-resolution tomography scans for selected regions of interest — without opening or modifying the battery.
- Scan the intact sample to identify areas of interest
- Zoom in for high resolution imaging in a single pass—without any sample preparation
Scout & Zoom workflow from 0.4x overview scan to 4x and 20x Resolution at a Distance.
- Perform structural analysis of cathode and anode recipe variants
- Develop methods that help balance the trade-offs of cost, safety, time to charge and energy density
Virtual cross section provides excellent contrast of cathode particles, resolves the microstructure of the graphite, and even shows the polymer separator against the electrolyte.
- Confirm the shape and distribution of cathode particles and fine tune calendaring pressure
- Look for welding burrs and separator pinch points
- Verify wetting and bubbles in electrolyte
Comparison between two electrodes with different distribution, homogeneity and density of cathode particles due to pressure variation during the calendaring process.
- Infer chemical changes from structural data
- See particle formation on the separator
- All within an intact battery, and across hundreds of charge cycles
Runaway SEI layer growth around an Si anode particle after 100x charge cycles. XRM tomography shows contrast of organic materials which would dissolve under SEMRunaway SEI layer growth around Si anode particle after 100x charge cycles. 3D X-ray microscopy (XRM) shows contrast of organic materials which would be indiscernible under SEM.
Get in touch with us to find out more about the benefits of ZEISS Microscopy Solutions for your research, book a demo at our customer center, or get a quote. We are looking forward to hearing from you.