Tests in a Li-ion half cell at WMG, University of Warwick (UK), of Ceylon Graphite’s commercial spherodized, silicon-enhanced vein graphite materials yielded a 446 mAh/g specific discharge capacity (SDC) for the materials—13% higher than what is achieved for vein graphite on its own (393 mAh/g) under the same testing conditions. The synthetic comparison data is from earlier test work performed at WMG.

We had very good results from our initial coin cell battery tests as well as our full cell test, but I am excited to see the performance improvement of vein graphite with silicon enhancements. These results are a highly significant development for Ceylon, and we believe we can further improve these numbers as we continue perfecting the technology.

The unique characteristics of our Sri Lankan vein graphite combined with our proprietary processing technologies produces a Li-ion battery with significantly higher power and energy as tested by WMG. In addition, we believe that the energy consumption of the end-to-end process of producing battery-grade anode material from vein graphite is the lowest, relative to synthetic and flake graphite, because vein graphite from Sri Lanka does not require primary processing, due to the high in situ grade above 90%Cg.

—Ceylon CEO Don Baxter

Spherodized silicon-enhanced vein graphite materials

Known under various names including crystalline vein, Plumbago, Sri Lankan graphite, and Ceylon graphite, “Sri Lankan” and “Ceylon” are commonly used for vein graphite since Sri Lanka (formerly known Ceylon) is the only area to produce this material in commercial quantities, the company notes.

Vein graphite is a true vein mineral, as opposed to a seam mineral (amorphous graphite) or a mineral that is disseminated throughout the ore rock (as in flake graphite).

WMG is an academic department at the University of Warwick, focused on collaboration between academia and the public and private sectors.