Mason Graphite Inc., Laval, Quebec, Canada, (TSX.V: LLG; OTCQX: MGPHF) has announced excellent cycling test results of complete, prototype-type lithium-ion batteries, containing the Company’s coated spherical graphite produced at pilot scale. The coated spherical graphite, a value-added product, will serve the lithium-ion battery market, notably for electric vehicles.
Thus, the batteries made with graphite from the Lac Guéret deposit, in the anode, have maintained 86% of their original capacity after 470 cycles of charge and discharge (see graph below). This a remarkable performance, considering that for such prototype batteries, the target in the electric vehicle application is a minimum of 80% of retention after typically 500 cycles, the company says These same batteries continue cycling at NRC to validate that this objective will be reached and to evaluate their life expectancy.
From a technological perspective for the cycling tests, the batteries were charged and discharged at a rate of C/3 (3 hours to charge, 3 hours to discharge), which corresponds to the conditions typically used for electric vehicles. The cathode used for the test was a commercial material of NMC532 type.
Gilles Gingras, chairman of the Board of Directors of the Company commented: “After many years of work and based on our industrial approach, the experience and expertise of our team allowed us to reach excellent results with our coated spherical graphite project. That these results have been obtained with samples produced at the pilot scale, and not laboratory scale, clearly demonstrates how advanced our project is.”
Important Partnerships
The prototype full pouch cell type batteries were assembled on the new prototyping line of NRC National Research Council Canada Industrial Materials Institute in Boucherville, Quebec, Canada, long-term partner of the Company for the development of its spherical graphite grades, and tested in NRC’s laboratories. The spherical graphite from the Company was successfully processed during all the battery assembly steps. Furthermore, the cells made with Mason Graphite’s material have demonstrated, before the cycling tests, a capacity (in mAh) comparable to the capacity obtained with commercially available material tested in parallel under the same conditions.
The coated spherical graphite tested was produced at the pilot scale (continuous processing feed capacity of a few tens of kilograms per hour) in the installations of COREM, Quebec, Canada, important partner of the Company since 2014, and in the installations of the Company.
The properties of Mason Graphite coated spherical graphite are:
- High purity (minimum 99.95 %Cg);
- Optimized grain size (average particle size of around 20 µm);
- Low specific surface (around 3 m2/g); and
- High taped density (> 1.1 g/cm3), denoting the high sphericity level for the graphite particles.
Step by Step
The Company had announced, almost a year ago (December 10th, 2019), that the coated spherical graphite had passed with success the preliminary electrochemical tests in half-cells (graphite vs lithium) and had therefore qualified to be tested in full cells (graphite vs cathode). Mason Graphite plans a new pilot production campaign of coated spherical graphite early 2021, which should be followed by a new sequence of cycling tests. The objectives of this campaign are to demonstrate repeatability of the processes, to apply recent optimization results and to prepare samples for potential customers evaluation.
About Mason Graphite
Mason Graphite is a Canadian corporation dedicated to the production and transformation of natural graphite. Its strategy includes the development of value-added products, notably for green technologies like transport electrification. The Company also owns 100% of the rights to the Lac Guéret graphite deposit, one of the richest in the world. The Company is managed by an experienced team cumulating many decades of experience in graphite, covering production, sales, as well as research and development.