Westwater Resources, Inc., an explorer and developer of U.S.-based mineral resources essential to the clean energy industry, today announced that independent performance testing of its ULTRA-CSPG™ (Coated Spherical Purified Graphite "CSPG") material produced in a laboratory setting shows that it performs as well or better than benchmark commercially available natural flake and synthetic materials.
ULTRA-CSPG™ is Westwater's anode material which is utilized in lithium ion batteries, which are used in the fast-growing electric vehicle market.
Christopher M. Jones, President and Chief Executive Officer, said, "The positive test results on spherical purified graphite, which follow the positive independent test results on our first lab-produced graphite, ULTRA-PMG™, demonstrates that we are progressing with the commercialization of these American-made battery-grade graphite materials. To this end, plus the addition of new Vice President of Sales and Marketing, Jay Wago, an industry veteran with 20 years' experience in battery materials marketing and development, we are preparing to bring these materials to the marketplace."
Westwater has produced ULTRA-CSPG™ product using laboratory-scale equipment that simulates full-scale production from purification to spheroidization and coating.
The Company has been working with Dorfner AnzaPlan in Germany and Polaris Laboratories in the United States ("Polaris") to commercialize processing methodology to produce various sizes of ULTRA-CSPG™ products. ULTRA-CSPG is Westwater's anode material for use in Lithium Ion batteries. These batteries are used in the fast-growing electric vehicle market.
Initial processing runs comprised of purification, milling and spheroidization produced spherical purified graphite samples with an average particle size of 13.5 micrometers; these samples were then sent to Polaris, an independent laboratory in the USA, for testing to evaluate the product's performance. Samples were then surface coated and assembled into half-cell coin cells (an industry standard testing method).
Polaris measured electrochemical performance at different continuous discharge rates (C-rates) from 0.1C to 2C. The first 13 cycling lithiation/de-lithiation tests (the incorporation of lithium into an electrode in a lithium-ion battery) achieved 9.6% irreversible capacity loss and 353.5 mAhr/g reversible capacity at 0.1C rate (C/10).
After initial cycle tests, 10 cycles of power testing were conducted from C/5 to 2C rates.
These power results were similar to the results obtained for industry benchmark graphite materials and, following power tests, 4 cycles at C/10 rates were performed. These tests also showed C/10 capacities slightly higher than the initial reversible capacity, indicating fade is not a significant feature for Westwater's CSPG.
The coulombic efficiencies (the efficiency with which charge is transferred in a system facilitating an electrochemical reaction) after the first cycle were about 99.9%. During cycling, area specific impedance (ASI) values in ohm-cm2 were recorded.
ASI values ranged from 20-40 ohm-cm2, which was slightly better than nominal values for benchmark materials in the 30-50 ohm-cm2 range for the same conditions. Westwater continues to optimize spheroidization processes and cell test conditions (calendar density, electrolyte chemistry, coat loading rate, BET surface area, etc.).