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High-Grade Pollucite Confirmed as Main Caesium Host Mineral at the Vega and Rigel Zones Identification of other potential high-value by-products within the existing lithium Mineral Resource shows the highly evolved pegmatites at Shaakichiuwaanaan as a potential major

Exploration Programs

High-Grade Pollucite Confirmed as Main Caesium Host

Mineral at the Vega and Rigel Zones

Identification of other potential high-value by-products within the existing lithium Mineral

Resource shows the highly evolved pegmatites at Shaakichiuwaanaan as a potential major

host for further critical metals.

June 10, 2025 – Vancouver, BC, Canada June 11, 2025 – Sydney, Australia

HIGHLIGHTS

• Pollucite confirmed as the principal mineral host for the caesium discovered

recently at both the Vega and Rigel zones at the CV13 Pegmatite:

o Pollucite is considered the optimal mineral host for caesium in Li-Cs-Ta

(“LCT”) pegmatites due to its high caesium content (typically >30%) and its relative

ease of processing and recovery.

o Up to 75% pollucite in individual core sample (1.1 m at 26.6% Cs2O1).

• Caesium within the Vega and Rigel zones will be included in the next Mineral

Resource update for the Project, targeted for Q3-2025. Interpreted sizes of the Vega

and Rigel zones are significant – footprints of ~800 m x 250 m (Vega) and ~200 m x 100 m

(Rigel).

• The Company has commenced evaluating options to advance and incorporate

the caesium opportunity at CV13 as a potential by -product into the overall

economic development of the Project , to follow completion of the lithium -only

Feasibility Study on the CV5 Pegmatite.

• Caesium pricing varies based on its end-product form and purity; however, in its refined

form, caesium metal (Cs >99.5%) is a high value commodity similar to gold and currently

trades around US$2,540/oz (excluding VAT, Source – Shanghai Metal Markets).

• Shaakichiuwaanaan LCT pegmatites are highly evolved through the process of

crystal fractionation during formation, resulting in extreme enrichment of lithium,

caesium, and tantalum – each at potentially world-class scale.

• Tantalum and gallium are already part of the existing Mineral Resource with potential

to become meaningful future by-products.

• The lithium-only Feasibility Study based on the CV5 Mineral Resource

component remains on-track for completion in Q3 -2025, with the economic

potential of the critical metal by-products to be assessed thereafter.

1 Refer to news release dated April 9, 2025.

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Ken Brinsden, President, CEO, and Managing Director, comments: “The confirmation of widespread

pollucite mineralization – the optimal host mineral for caesium – at the Vega and Rigel zones marks

another important step forward in evaluating the economic potential of th is exciting discovery. As we

advance towards a preliminary mineral processing program to evaluate recovery of caesium, the team is

working on a maiden MRE for caesium that is anticipated to be announced before the end of third-quarter

2025.

“The presence of significant caesium mineralization at Shaakichiuwaanaan , in addition to lithium and

tantalum, reinforces the amazing endowment of the geology and the potential for other critical and

strategic metals to further enhance and diversify future Project economics. We are very keen to explore

these value-add opportunities on top of what is already recognized as a world -class lithium pegmatite in

its own right,” added Mr. Brinsden.

PATRIOT BATTERY METALS INC. (THE “COMPANY” OR “PATRIOT”) (TSX: PMET) (ASX:

PMT) (OTCQX: PMETF) (FSE: R9GA) is pleased to provide an update on caesium – a high-

value critical and strategic metal – identified at the CV13 spodumene pegmatite, at its 100%-owned

Shaakichiuwaanaan Property (the “Property” or “Project”) located in the Eeyou Istchee James Bay

region of Quebec. The CV13 Spodumene Pegmatite is located approximately 3 km west-southwest

along geological trend of the CV5 Spodumene Pegmatite, which is situated approximately 13 km

south of the regional and all‑weather Trans-Taiga Road and powerline infrastructure corridor, and

is accessible year-round by all-season road.

The Shaakichiuwaanaan Li-Cs-Ta (“LCT”) pegmatites are highly evolved through the

process of crystal fractionation during formation, whereby mineral crystallization leads to

progressive changes in the chemistry of the remaining melt, resulting in increasingly rare minerals

being formed as the process unfolds. This process of pegmatite formation most commonly leads

to only modest enrichment of lithium and other critical metals. However, in the LCT pegmatites

at Shaakichiuwaanaan this process has resulted in the extreme enrichment of lithium,

caesium, and tantalum – each at potentially world-class scale – as well as other potentially

recoverable critical and strategic metals (e.g., gallium).

Each of these critical metals could become further value-added by-products to the envisioned

lithium operation at Shaakichiuwaanaan. Additional information is provided below describing the

caesium opportunity and the steps being taken to evaluate development of this unique asset .

Further details will be provided on the other potential by-products identified, including tantalum

and gallium, in the coming weeks.

CAESIUM OPPORTUNITY

In news releases dated March 2 and April 9, 2025, the Company announced the discovery of

significant caesium mineralization in drill hole at the CV13 Pegmatite within the Vega and Rigel

zones. Initial drill results include:

 11.1 m at 4.87% Cs2O, including 7.1 m at 7.39% Cs2O (Vega, CV24-520), and

 5.0 m at 13.32% Cs2O, including 2.0 m at 22.90% Cs2O (Rigel, CV23-255).

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The Company is pleased to report that XRD-Rietveld mineralogical analysis completed on

drill core samples from the Vega and Rigel caesium zones has confirmed pollucite as

the dominant caesium-bearing mineral present (Figure 1). A pollucite content high of 74.2%

was reported over 1.1 m in drill hole CV23-204, assaying 26.6% Cs2O.

Pollucite is considered the optimal mineral host to c aesium in LCT pegmatite s due

to its very high caesium content (typically >30%) and its relative ease of processing

and recovery. Pollucite is typically recovered using standard and conventional ore sorting

methods as well as potential secondary flotation. The Company has completed collection of drill

core samples from the Vega Zone for an ore sorting test program that will evaluate pollucite

(caesium) concentrate recovery ahead of the typical spodumene (lithium) and tantalite (tantalum)

recovery circuits.

Figure 1: Pollucite mineralization in high-grade caesium drill intersection at ~64.5 m depth in drill hole

CV23-271 at th e Rigel Zone, CV13 Pegmatite. Interval grades 2 22.69% Cs2O over 1.0 m ( 64.0 m to

65.0 m) with XRD-Rietveld reporting a pollucite content over the interval of 58%.

Using a 0.5% Cs2O grade constraint within the wider CV13 Pegmatite body, the interpreted extent

of the Vega and Rigel caesium zones has been further refined (Figure 2). The footprint of caesium

mineralization at the Vega Zone has been traced over a general area of at least 800 m x

250 m and consists of two proximal flat-lying lenses, at a depth of ~110 m, with a true thickness

of <2 m and up to ~10 m and ~ 6 m, respectively. At Rigel, the footprint of caesium

mineralization has been traced over a general area of least 200 m x 100 m and consists

of a single, shallow dipping lens at a depth of ~50 m with a true thickness of <2 m to ~6 m.

The interpreted dimensions for the Vega and Rigel caesium zones will form the primary constraints

to the subsequent block modelling and Mineral Resource Estimate anticipated to be announced in

Q3-2025.

Mineral deposits of caesium (pollucite hosted) are extremely rare globally and represent

the most fractionated component of LCT pegmatite systems, which are effectively the only primary

2 Refer to news release dated April 9, 2025.

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source of caesium globally . Economic deposits of c aesium pegmatite are typically on a

smaller scale of <10 kt to 350 kt in size compared to deposits of lithium pegmatite that typically

range in the millions of tonnes in size (<10 Mt and rarely over 100 Mt).

Figure 2: Interpreted footprints of the Vega and Rigel caesium zones based on a 0.5% Cs2O grade

constraint within the wider CV13 Pegmatite body.

Globally, it is estimated only three (3) primary caesium mines have historically operated and all

were pollucite hosted – Tanco (Canada), Bikita (Zimbabwe), and Sinclair (Australia). At Bikita and

Sinclair, the pollucite resources were exhausted in 2018 and 2019, respecti vely. Tanco is

understood to be approaching the end of its mine -life with extraction from existing tailings piles

and/or mine remnants being explored. At Sinclair3, the mine produced 18,629 tonnes of pollucite

3 Management cautions that past results or discoveries on other mineral properties or mines owned by third parties

(i.e., Tanco, Bikita, Sinclair) may not necessarily be indicative to the presence of mineralization on the Company’s

properties or the economic viability of any such mineralization . There can be no assurance that future exploration

efforts will result in the identification of mineral resources or reserves.

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pegmatite ore grading 8.3% Cs 2O for a contained metal content of 1,551 tonnes Cs 2O. In

comparison to the size of the interpreted caesium zones at Vega ( ~800 m x 250 m) and Rigel

(~200 m x 100 m), the primary ore body at Sinclair was relatively small and measured ~60 m long,

up to 20 m wide, and up to 10 m thick, and was situated at a depth~40 m from surface.

NEXT STEPS

Through the lithium focused exploration and resource development drilling to date at the

Property, the Company has identified other high-value critical metal potential by -

products in addition to the existing large- scale lithium Mineral Resource at Shaakichiuwaanaan,

namely caesium, tantalum, and gallium.

The caesium within the Vega and Rigel zones at the CV13 Pegmatite will be included in the next

Mineral Resource update for the Project, targeted for Q3 -2025. This MRE, which will be the 4 th

for the Project, will then include lithium, caesium, tantalum, and gallium and form the basis for

further evaluation of secondary critical metal recovery to the primary lithium. Each of these critical

metals has the potential to become a meaningful future by -product as part of the overall future

Project development at Shaakichiuwaanaan.

The lithium-only Feasibility Study based on the CV5 Mineral Resource component of the overall

Shaakichiuwaanaan MRE is on-track for completion in Q3-2025 and remains the near-term focus

for the Company. The economic potential in critical metal by-products will be assessed thereafter,

with various studies underway concurrently to better evaluate the opportunities present for

caesium, tantalum, and gallium specifically.

The Company has completed its collection of caesium mineralized drill core from the Vega Zone

and anticipates an ore-sorting test program for the recovery of pollucite (caesium) to begin shortly.

Additionally, the Company has recently completed a tantalum recovery program at SGS Canada’s

Lakefield facility using anticipated early mine-life open-pit and underground material from the CV5

Pegmatite and is compiling the results.

CAESIUM MARKET

Caesium is listed as a critical and strategic metal by the province of Quebec (Canada), Canada,

Japan, and the United States. Mineral deposits of caesium (in pollucite) are extremely rare globally.

Due to its high-density, low toxicity, biodegradable nature and recoverability, c aesium is used to

support the completion of oil and gas wells at high pressure and temperature. Caesium isotopes

are used as an atomic resonance frequency standard in chip scale atomic clocks, playing a vital role

in aircraft guidance systems, global positioning satellites, internet and cellular telephone

transmissions, and scientific medical research.

The caesium market's growth is estimated to be primarily driven by increasing demand in the

medical, space, and oil & gas exploration industries. Caesium chloride, in particular, is expected to

be the fastest -growing product segment due to its applications in medical imaging and cancer

therapy.

Caesium pricing varies based on its end -product form and purity; however, in its refined form,

caesium metal (Cs >99.5%) is a high value commodity similar to gold and currently trades around

US$2,540/oz (excluding VAT, Source – Shanghai Metal Markets).

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QUALIFIED/COMPETENT PERSON

The information in this news release that relates to exploration results for the Shaakichiuwaanaan

Property is based on, and fairly represents, information compiled by Mr. Darren L. Smith, M.Sc.,

P.Geo., who is a Qualified Person as defined by National Instrument 43-101 – Standards of Disclosure

for Mineral Projects, and member in good standing with the Ordre des Géologues du Québec (Geologist

Permit number 01968), and with the Association of Professional Engineers and Geoscientists of

Alberta (member number 87868). Mr. Smith has reviewed and approved the technical information

in this news release.

Mr. Smith is an Executive and Vice President of Exploration for Patriot Battery Metals Inc. and

holds common shares, Restricted Share Units (RSUs), and Performance Share Units (PSUs) in the

Company.

Mr. Smith has sufficient experience, which is relevant to the style of mineralization, type of deposit

under consideration, and to the activities being undertaken to qualify as a Competent Person as

described by the Australasian Code for Reporting of Exploration Results, Mineral Resources and

Ore Reserves (the JORC Code). Mr. Smith consents to the inclusion in this news release of the

matters based on his information in the form and context in which it appears.

ABOUT PATRIOT BATTERY METALS INC.

Patriot Battery Metals Inc. is a hard -rock lithium exploration company focused on advancing its

district-scale 100%-owned Shaakichiuwaanaan Property (formerly known as Corvette) located in

the Eeyou Istchee James Bay region of Quebec, Canada, which is acce ssible year-round by all -

season road and is proximal to regional powerline infrastructure. The Shaakichiuwaanaan Mineral

Resource4, which includes the CV5 & CV13 spodumene pegmatites, totals 108.0 Mt at 1.40% Li2O

Indicated, and 33.3 Mt at 1.33% Li2O Inferred, and ranks as the largest lithium pegmatite resource

in the Americas, and the 8 th largest lithium pegmatite resource in the world. 5 Shaakichiuwaanaan

also holds significant potential for other critical and strategic metals including caesium, tantalum,

and gallium.

A Preliminary Economic Assessment (“PEA”) was announced for the CV5 Pegmatite (lithium) on

August 21, 2024, and highlights Shaakichiuwaanaan as a potential North American lithium raw

materials powerhouse. The PEA outlines the potential for a competitive and globally significant

high-grade lithium project targeting up to ~800 ktpa spodumene concentrate using a simple Dense

Media Separation (“DMS”) only process flowsheet.

For further information, please contact us at [email protected] or by calling +1 (604)

279-8709, or visit www.patriotbatterymetals.com. Please also refer to the Company’s continuous

4 Shaakichiuwaanaan (CV5 & CV13) Mineral Resource Estimate ( 108.0 Mt at 1.40% Li2O, 166 ppm Ta2O5 and 66 ppm

Ga, Indicated, and 33.3 Mt at 1.33% Li2O, 156 ppm Ta2O5, and 65 ppm Ga, Inferred) is reported at a cut -off grade of

0.40% Li2O (open-pit), 0.60% Li 2O (underground CV5), and 0. 70% Li2O (underground CV13) with an Effective Date of

January 6, 2025 (through drill hole CV24 -787). Mineral resources are not mineral reserves as they do not have

demonstrated economic viability.

5 Refer to news Release dated May 12, 2025, for supporting information.

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disclosure filings, available under its profile at www.sedarplus.ca and www.asx.com.au, for available

exploration data.

This news release has been approved by the Board of Directors.

“KEN BRINSDEN”

Kenneth Brinsden, President, CEO, & Managing Director

Olivier Caza-Lapointe

Head, Investor Relations – North America

T: +1 (514) 913-5264

E: [email protected]

APPENDIX 1 – JORC CODE 2012 TABLE 1 (ASX LISTING RULE 5.8.2)

Section 1 – Sampling Techniques and Data

Criteria JORC Code explanation Commentary

Sampling techniques • Nature and quality of sampling (eg cut

channels, random chips, or specific

specialized industry standard

measurement tools appropriate to the

minerals under investigation, such as

down hole gamma sondes, or handheld

XRF instruments, etc). These examples

should not be taken as limiting the

broad meaning of sampling.

• Include reference to measures taken to

ensure sample representivity and the

appropriate calibration of any

measurement tools or systems used.

• Aspects of the determination of

mineralization that are Material to the

Public Report.

• In cases where ‘industry standard’

work has been done this would be

relatively simple (eg ‘reverse

circulation drilling was used to obtain 1

m samples from which 3 kg was

pulverized to produce a 30 g charge for

fire assay’). In other cases more

explanation may be required, such as

where there is coarse gold that has

inherent sampling problems. Unusual

commodities or mineralization types

(eg submarine nodules) may warrant

disclosure of detailed information.

• XRD Rietveld mineralogical analysis was completed on

select drill core sample pulps of pegmatite and host

rock.

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Criteria JORC Code explanation Commentary

Drilling techniques • Drill type (eg core, reverse circulation,

open-hole hammer, rotary air blast,

auger, Bangka, sonic, etc) and details

(eg core diameter, triple or standard

tube, depth of diamond tails, face -

sampling bit or other type, whether

core is oriented and if so, by what

method, etc).

• N/A. No drill results reported.

Drill sample

recovery

• Method of recording and assessing

core and chip sample recoveries and

results assessed.

• Measures taken to maximize sample

recovery and ensure representative

nature of the samples.

• Whether a relationship exists between

sample recovery and grade and

whether sample bias may have

occurred due to preferential loss/gain

of fine/coarse material.

• N/A. No drill results reported.

Logging • Whether core and chip samples have

been geologically and geotechnically

logged to a level of detail to support

appropriate Mineral Resource

estimation, mining studies and

metallurgical studies.

• Whether logging is qualitative or

quantitative in nature. Core (or

costean, channel, etc) photography.

• The total length and percentage of the

relevant intersections logged.

• N/A. No drill results reported.

Sub-sampling

techniques and

sample preparation

• If core, whether cut or sawn and

whether quarter, half or all core taken.

• If non -core, whether riffled, tube

sampled, rotary split, etc and whether

sampled wet or dry.

• For all sample types, the nature, quality

and appropriateness of the sample

preparation technique.

• Quality control procedures adopted

for all sub-sampling stages to maximize

representivity of samples.

• Measures taken to ensure that the

sampling is representative of the in situ

material collected, including for

instance results for field

duplicate/second-half sampling.

• Drill core pulps were prepared for analysis by SGS

Canada Inc. using XRD Rietveld analysis.