Analysing Graphite with SEM in Lithium Ion Battery Development
How desktop SEM can used in lithium ion battery development to analyse graphite and battery materials. Easy-to-use, automated desktop systems can be used in-house to characterise samples for faster results, accelerating the battery development process.
Graphite in Lithium-Ion Batteries
Graphite is a key component of lithium-ion batteries. It’s the primary material used for the anode. It’s abundant, low cost and has a long cycle life.
Natural graphite usually contains flakes, which must be converted into a spherical form before they can be used as an anode material. Alternatively, synthetic graphite can be produced in a ready-to-use format. The process has to be controlled to ensure consistent quality, which involves temperatures up to 3000°C.
By optimising the morphology of the graphite, the properties of the anode can be improved. Spherical graphite particles pack more efficiently, which improves the overall conductivity, as well as many other benefits:
- Higher rate capability.
- Higher energy density.
- Lower first cycle irreversible capacity loss.
- Longer cycle life.
- Improved safety performance.
A Scanning Electron Microscope (SEM) can be used to examine the morphology of the particles. The resolution is superior to optical microscopes, which aren’t suitable for black powders like graphite.
The example below shows graphite particle images taken with the Thermo Scientific Phenom XL desktop SEM. Natural graphite was compared to synthetic graphite particles with five different treatments to find the most effective production processes.
In-House, Desktop SEM
Traditionally, SEM in expensive – both the equipment and the expertise required to operate the system, so samples are often sent to a testing lab. This takes time while you wait for the results to be sent back.
Thermo Scientific’s range of desktop SEM instruments are designed to be easier to use, making SEM more accessible so you can use it in-house. This improves turnaround times and speeds up research, as you can perform your own analyses after just a small amount of training.
Desktop SEM systems are much smaller than traditional floor-standing SEMs, and do not require a special facility, making them a practical option for the in-house lab.
Up to 36 samples can be tested in a run, using a dedicated Auto-Scan script. This generates over 200 images in less than 30 minutes. The script is easy to use: simply choose the number of positions to analyse and the magnification level required. The system can then be left to run unattended overnight, acquiring the images for you. This means that repetitive testing work in battery development can be automated, to save time.
Automation also eliminates the variations in image quality that can occur when images are acquired by different people.
The Phenom XL can generate images at 10 nanometre resolution, which is ideal for 20-micron graphite particles.
The user interface is designed to be accessible and intuitive. After minimal training the system can be operated easily by anyone who needs it, without a SEM specialist.
- Automated features:
- Easy to use.
- Saves time.
- Less human error.
- Leave repetitive tasks to run overnight.
- Step-by-step guided workflow.
- Average time-to-image of 60 seconds.
- Long-life CeB₆ source – yields more detailed images than tungsten.
A demonstration of the Phenom XL from sample loading to imaging and analysis:
How automation saved 36 hours per week at a semiconductor device assembly company and helped increase quality standards:
Blue Scientific is the official distributor of Thermo Scientific entry-level SEM in the UK and Ireland. We’re available to provide quotes, demonstrations and answer all your questions – just get in touch: