A provisional patent for a novel anode technology for lithium-ion batteries has been filed by Canadian IP development and commercialisation company Zentek.
Filed with the United States Patent and Trademark Office, the innovation has the potential to improve lithium-ion batteries by using a graphene-wrapped silicon anode.
The firm has demonstrated the technology with laboratory-scale half-cells, and was validated with commercial lithium iron phosphate cathodes, which suggests they could be a drop-in solution for existing battery technologies.
The anode was developed by Michael Pope (pictured), an associate professor in the Department of Chemical Engineering at the University of Waterloo along with his colleagues Dr. Marianna Uceda and Dr. Zimin She.
A paper on the technology was published in the peer-reviewed scientific journal ACS Applied Materials & Interfaces.
Key characteristics of graphene-wrapped silicon anode include:
- At practical mass loading of 2.5mg/cm2, the electrode achieved 2.04 mAh/cm2 and retained 79% of this capacity after 200 cycles against a lithium half-cell
- When paired with a commercial lithium iron phosphate cathode, the fully assembled battery retained 93.3% of its initial capacity over 100 cycles
- Works with current lithium-ion batteries as a replacement for graphite
- Requires further development and optimization work before it can be commercialised.
Pope said: “Silicon is poised to replace graphite as the dominant anode material in current lithium-ion and future, next-generation batteries.
“However, silicon expands by over 300% when the battery is charged and discharged, which has limited commercialisation efforts.
“Our lab, through ongoing efforts supported by Zentek and the Natural Sciences and Engineering Research Council of Canada, has developed an improved method to enable high capacity, high cycle-life anodes by encapsulating them in a protective, crumpled graphene shell using a simple spray drying approach often used to generate much of the world’s dry powders.”