VANCOUVER, BC, Nov. 24, 2021 /CNW/ - South Star Battery Metals
Corp. ("South Star" or the "Company") (TSXV: STS)
(OTCQB: STSBF), along with its technological partner in
the United States ("US
Lab"1), are pleased to announce the successful final
life cycle testing results for over 100 cycles (charging and
discharging) in CR2016 LiB coin cells constructed with anode
material (coated spherical purified graphite – "SPG") produced from
the Santa Cruz Graphite Project. In separate test work, a highly
conductive dispersion was also tested that exceeds current industry
standards for conductive coating applications in both energy
storage and advanced purity dry film lubrication markets.
South Star's cycle testing program is complete and exceeded 100
cycles for the LiB cells. One cycle consists of 10 hours of charge
and 10 hours of discharge, therefore 100 cycles equal approximately
2,000 hours total. The tests indicate very stable results with
approximately 2.2% degradation through 100+ cycles while
maintaining reversible capacity on the order of 342 – 345 mAh/g
throughout. If these results were projected out, approximately 900
cycles could be achieved before reaching the 20% industry standard
cutoff. These results are generally competitive with synthetic
graphite and indicates that the Santa
Cruz's battery anode material are excellent quality material
that are suitable for a variety of LiB applications including EV
markets. Upcoming work includes sample preparation of various
downstream products so that the qualification process can begin
along with processing flowsheet optimizations and performance
validation. (Refer to September 22,
2021 press release for results from initial 75 cycles).
In addition, South Star has successfully completed the
production and testing of high purity graphite and premium quality
electrically conductive dispersions for a variety of applications
including the alkaline battery markets. The Santa Cruz material utilized was harvested
from the purified graphite rejects from the spheronization process
and confirmed that purified flake graphite from the Santa Cruz project is significantly more
conductive than industry-leading material currently in use. With
the alkaline battery market producing over 12 billion batteries
annually and a global market value in excess of US$7.5B in 2020, this application could
potentially develop into a key market for South Star.
"We continue to announce stellar value add testing results that
prove the premium quality nature of the deposit while advancing
towards production in 2022," commented Richard Pearce, President and CEO of South Star.
"The final cycle testing with anode materials produced from
Santa Cruz concentrates resulted
in fantastic performance that approximates the characteristics of
synthetic graphite for a broad range of battery applications. In
addition, the development of such high-quality conductive
dispersions and coatings opens additional value-added markets for
our premium graphite. Our material outperformed the leading
commercial synthetic graphite products by a considerable margin.
Every single alkaline battery manufactured requires graphite, and
it is a huge new potential market because of the quality of our
concentrates. Premium coatings for alkaline battery cans are
currently priced up to $30,000 per
tonne. These are excellent outcomes for our program and continue to
prove that Santa Cruz can provide
a broad array of premium products and bring real value with natural
flake graphite to a diversified group of sectors and clients. We
have a bright future ahead of us."
Santa Cruz Product Information Bulletins (PIBs) with technical
information for the portfolio of products, safety data sheets
(SDSs) and marketing materials have been prepared and are being
distributed to our existing partners and potential clients.
100-200g samples of a variety of value-add products including
micronized and purified graphite, expanded & expandable
graphite, dispersions, as well as coated and uncoated SPG are being
produced and will be made available for qualification testing.
1 The United States laboratory
("US Lab") specializes in advanced graphite materials and value-add
testing for battery and non-battery applications. The US Lab
company name has not been published for the purposes of preserving
a commercial advantage of South Star Battery Metals in the
marketplace.
|
Lithium-Ion Battery Life Cycle Test Results
Purified graphite was successfully micronized using an advanced
pilot scale mechanical milling system outfitted with two air
classification circuits. Once the target sizing geometries were
achieved, uncoated SPG was produced by rolling and rounding the
micronized graphite into elliptical spheres in a specialized mill.
The elliptical shapes are a preferred morphology for higher packing
density active loadings in battery electrodes. They are also
preferred due to better rate capacities, safer and generally
longer-life LiBs. Uncoated SPG was coated with a nanolayer of soft
carbon and heat treated under a blanket of inert gas. The hardened
coating provides a layer of protection from exfoliation and general
degradation during the normal expansion and contraction cycles
associated with charging and discharging. The coating also reduces
ongoing reactions of electrolytes with the graphitic carbon, which
results in a reduced battery life (See
June 29th, 2021 press release for more
details).
Next, a copper foil was coated with the anode slurry using the
drawdown technique, and the electrode was dried under vacuum and
weighed. Finally, the anode was welded to the bottom can of a
stainless-steel standard CR2016 coin cell. Three identical coin
cells were produced, and testing includes the following: reversible
capacity, irreversible capacity, irreversible capacity loss and
long-term cycling stability as a function of the elapsed number of
charge/discharge cycles.
As shown in Figure 1, other notable positive properties of
Santa Cruz anode material are that
their reversible capacities are at approximately 342-345 mAh/g
through 100 cycles, which is a degradation of 2.2 percent. Assuming
the current degradation rate remains constant, Santa Cruz graphite could potentially exceed
900 cycles prior to performance cut-off and provide a viable
alternative for the EV sector to synthetic graphite, which has
significantly higher costs, higher environmental footprint and is a
product derived from petroleum.
Figure 2 presents the results for Cell 3 through cycles 25, 50,
75, 100 and 115 and confirm that the cells maintain excellent
electrochemical performance throughout the current testing
confirming the robust nature of the Santa
Cruz natural crystalline flake characteristics as anode
material for lithium-ion batteries.
Figure 2: Cell 3 Cycles 25, 50, 75, 100 &
115 Testing Results
Premium Purity Conductive Coatings
The objective of this phase of testing was to formulate a
high-performance, premium-purity graphite-based conductive coating
product for the alkaline energy storage market using purified
Santa Cruz flake graphite. The
electrically conductive coatings require high conductivity, thermal
and chemical stability in the presence of corrosive electrolyte (37
wt% KOH), ultra-high purity (99.9+ wt% C) and high crystalline
flake structure.
During previous test work, South Star successfully produced
purified spherical graphite with a yield of approximately 74%
(Refer to news release dated June 29,
2021). The remaining 26% of the SPG process byproducts
retained their ultra-high purity level (99.9993%) and were
homogenized into a composite powder blend with a laser diffraction
measured mean particle size of 13.81 um with a broad size range of
0.972 to 104.6 um. This material was then added to a mixing tank
equipped with a dispersion blade. Water and surfactants were added
to breakdown agglomerates to further reduce the mean particle size
to 9.36 um.
US Lab's proprietary wet mill was utilized to achieve further
particle size reduction and incorporated a specialized media that
allows continued size reduction without cross contamination of the
end product with components of the media. The final dispersion had
a purity of 99.98+ wt.%C and a mean value of 4.0 um with a D10 =
1.018 um, D50 = 3.55 um and D90 = 8.01 um. The full particle size
distribution measured by laser diffraction is shown in Figure
3.
Figure 3. Particle size distribution (laser
diffraction by Microtrac S3500) of the wet milled Santa Cruz graphite, having purity of 99.98+
wt.%C.
The fine particle dispersion was mixed with a polyacrylate
co-polymer resistant to alkaline battery chemistry to produce an
alkaline battery can coating meeting current industry standards.
Additional water and solvent based polymer binders can be used in
future formulations to meet a variety of coating specifications
used in lithium primary, lithium-ion batteries, fuel cells and
supercapacitors. The final wet Quality Control specifications for
the South Star Alkaline Can Coating had the following
properties:
Property
|
Value
|
Test
Method
|
Viscosity
|
425 cps
|
Brookfield #3
spindle, 20 rpm, 25oC
|
WPG
|
9.53
lb/gal
|
Weight per
gallon
|
pH
|
9.6
|
|
Wt.%
solids
|
8.60%
|
30 minutes at
115oC (vacuum oven)
|
A thin coat of the final dispersion was applied to a glass
substrate and allowed to dry. The key property of these dried
coatings is electrical resistivity in ohm-inches measured by a 2T
probe (using a Fluke ohm-meter) on the glass substrate with 1 inch
between probes. The South Star graphite dispersion measured
electrical resistivity of 20 ohm-inches which is significantly
below current industry standards of <30 ohm-inches.
About South Star Battery Metals Corp.
South Star Battery Metals Corp. is a Canadian battery metals
project developer focused on the selective acquisition and
development of near-term production projects in the Americas. South
Star's Santa Cruz Graphite Project, located in Southern Bahia,
Brazil is the first of a series of
industrial and battery metals projects that will be put into
production. Brazil is the
second-largest graphite-producing region in the world with more
than 80 years of continuous mining. Santa
Cruz has at-surface mineralization in friable materials, and
successful large-scale pilot-plant testing (>30t) has been
completed. The results of the testing show that approximately 65%
of Cg concentrate is +80 mesh with good recoveries and 95-99% Cg.
With excellent infrastructure and logistics, South Star is carrying
its development plan towards Phase 1 production projected in Q4
2022, pending financing. South Star trades on the TSX Venture
Exchange under the symbol STS, and on the OTCQB under the symbol
STSBF.
South Star is committed to a corporate culture, project
execution plan and safe operations that embrace the highest
standards of ESG principles based on transparency, stakeholder
engagement, ongoing education and stewardship. To learn more,
please visit the Company website at
http://www.southstarbatterymetals.com.
This news release has been reviewed and approved by Richard
Pearce, P.E., a "Qualified Person" under National Instrument 43-101
and President and CEO of South Star Battery Metals.
On behalf of the Board,
Mr. Richard Pearce
Chief Executive Officer
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CAUTIONARY STATEMENT
Neither the TSX Venture Exchange nor its Regulation Services
Provider (as that term is defined in policies of the TSX Venture
Exchange) accepts responsibility for the adequacy or accuracy of
this press release.
This news release and the Updated Technical Report contain
references to inferred resources. The Report is preliminary in
nature and includes inferred mineral resources that are considered
too speculative geologically to have the economic considerations
applied to them that would enable them to be categorized as mineral
reserves.
FORWARD-LOOKING INFORMATION
The information contained herein contains "forward-looking
statements" within the meaning of applicable securities
legislation. Forward-looking statements relate to information that
is based on assumptions of management, forecasts of future results,
and estimates of amounts not yet determinable. Any statements that
express predictions, expectations, beliefs, plans, projections,
objectives, assumptions or future events or performance are not
statements of historical fact and may be "forward-looking
statements".
Forward-looking statements are subject to a variety of risks
and uncertainties which could cause actual events or results to
differ from those reflected in the forward-looking statements,
including, without limitation: risks related to failure to obtain
adequate financing on a timely basis and on acceptable terms; risks
related to the outcome of legal proceedings; political and
regulatory risks associated with mining and exploration; risks
related to the maintenance of stock exchange listings; risks
related to environmental regulation and liability; the potential
for delays in exploration or development activities or the
completion of feasibility studies; the uncertainty of
profitability; risks and uncertainties relating to the
interpretation of drill results, the geology, grade and continuity
of mineral deposits; risks related to the inherent uncertainty of
production and cost estimates and the potential for unexpected
costs and expenses; results of prefeasibility and feasibility
studies, and the possibility that future exploration, development
or mining results will not be consistent with the Company's
expectations; risks related to commodity price fluctuations; and
other risks and uncertainties related to the Company's prospects,
properties and business detailed elsewhere in the Company's
disclosure record. Should one or more of these risks and
uncertainties materialize, or should underlying assumptions prove
incorrect, actual results may vary materially from those described
in forward-looking statements. Investors are cautioned against
attributing undue certainty to forward-looking statements. These
forward-looking statements are made as of the date hereof and the
Company does not assume any obligation to update or revise them to
reflect new events or circumstances. Actual events or results could
differ materially from the Company's expectations or
projections.
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SOURCE South Star Battery Metals Corp.