Large, High-Grade Cesium Discovery Confirmed at

Large, High-Grade Cesium Discovery Confirmed at Shaakichiuwaanaan, Canada Potentially adding a further critical mineral and valuable by-product to a world-class lithium project

April 9, 2025 – Vancouver, BC, Canada April 10, 2025 – Sydney, Australia

HIGHLIGHTS

• Wide, high-grade cesium pegmatite drill intercepts identified at the CV13 Pegmatite from assay overlimit analysis, including four (4) samples >20% Cs2O. Results include:

Vega Zone

• 18.1 m at 2.71% Cs2O, including 7.4 m at 5.45% Cs2O (CV24-754).
• 11.1 m at 4.87% Cs2O, including 7.1 m at 7.39% Cs2O (CV24-520).
• 5.7 m at 4.97% Cs2O, including 3.0 m at 8.20% Cs2O (CV24-525).
• 9.6 m at 1.59% Cs2O, including 4.4 m at 2.34% Cs2O (CV24-579).
• 3.0 m at 9.43% Cs2O, including 1.0 m at 22.41% Cs2O (Channel CH23-069).

Rigel Zone

• 5.9 m at 11.19% Cs2O, including 1.0 m at 22.69% Cs2O (CV23-271).
• 5.0 m at 13.32% Cs2O, including 2.0 m at 22.90% Cs2O (CV23-255).
• 3.2 m at 10.24% Cs2O, including 1.1 m at 26.61% Cs2O (CV23-204).
• 4.5 m at 3.36% Cs2O (CV23-198).
• The largest zone of cesium enrichment is coincident with the Company’s high-grade lithium Vega Zone (CV13) and can be traced through drilling over a very large area of ~600 m x 400 m ranging from 1-2 m to >10 m thick and remains open.
• The high-grade Rigel Zone, coincident with the apex of the structural flexure at CV13, is estimated through drilling to be at least ~200 m x 80 m in area and up to ~5 m thick.
• Mineralized cesium intercepts at the CV5 Pegmatite include:
• 10.4 m at 1.30% Cs2O, including 4.0 m at 2.02% Cs2O (CV23-117).
• 9.0 m at 1.20% Cs2O, including 1.5 m at 5.03% Cs2O (CV24-651).
• 7.5 m at 1.29% Cs2O, including 1.5 m at 3.90% Cs2O (CV24-404).
• 2.0 m at 5.24% Cs2O (CV23-219).
• 0.8 m at 13.04% Cs2O (CV24-627).

• Results are highly encouraging as cesium is a high-value commodity due to its rarity and specialized applications.

Patriot Battery Metals Inc.

Suite 700 - 838 W. Hastings Street, Vancouver, BC, Canada, V6C 0A6 www.patriotbatterymetals.com TSX: PMET / ASX: PMT / OTC: PMETF / FSE: R9GA

• Economically viable cesium deposits are very rare globally, but high value, and typically on a smaller scale of <10 kt to 350,000 kt in size and supported by drill intercepts of typically less than 3 to 10 m. This compares to lithium pegmatite deposits that typically range in the millions of tonnes (<10 Mt and rarely over 100 Mt) in size and are supported by much thicker drill intercepts.

Darren L. Smith, Patriot Executive and Vice President of Exploration, comments: “With the receipt of overlimit assay results, we have now confirmed a large cesium discovery at Shaakichiuwaanaan, supported by wide and well-mineralized drill intercepts. Cesium mineralization of this scale and grade, often combined with high-grade lithium and tantalum, is exceptionally rare globally and underscores the extraordinary endowment of the mineral system at Shaakichiuwaanaan in high-value critical minerals. While our primary focus remains steadfast on advancing the CV5 Deposit to production based on its world- class lithium endowment, the discovery of cesium presents a compelling value-add opportunity for the Company. Cesium is a high-value and rare commodity which has the potential to become a meaningful by- product to future lithium operations, complementing our core business.”

“Given the strategic importance and scarcity of cesium in global markets - and its growing use in key industrial and specialized applications – this discovery has the potential to significantly enhance stakeholder value and re-affirms Shaakichiuwaanaan as one of the top LCT pegmatite assets in the world. For this reason, the Company intends to further evaluate the cesium opportunity as we advance Shaakichiuwaanan towards development,” added Mr. Smith.

PATRIOT BATTERY METALS INC. (THE “COMPANY” OR “PATRIOT”) (TSX: PMET) (ASX: PMT) (OTCQX: PMETF) (FSE: R9GA) is pleased to announce the results of cesium (Cs) assay overlimit analysis, which reaffirm the discovery of two (2) distinct zones of cesium mineralization at the CV13 Pegmatite. The CV13 Pegmatite forms part of the Company’s 100% owned Shaakichiuwaanaan Property (the “Property” or “Project”), located in the Eeyou Istchee James Bay region of Quebec.

The Shaakichiuwaanaan Property hosts a consolidated Mineral Resource Estimate¹ (“MRE”) of 80.1 Mt at 1.44% LI2O Indicated and 62.5 Mt at 1.31% LI2O Inferred. The CV5 Spodumene Pegmatite, which forms the bulk of the MRE, is accessible year-round by all-season road and is situated approximately 14 km from a major hydroelectric powerline corridor. The CV13 Pegmatite is located <3 km along geological trend from the CV5 Pegmatite, and hosts additional lithium and tantalum resources, as well as recently discovered zones of cesium mineralisation (see news release dated March 2, 2025).

CV13 PEGMATITE

The initial discovery of two (2) distinct zones of cesium enrichment at CV13 was first announced in the Company’s news release dated March 2, 2025, and was based on drill hole pegmatite intercepts which had returned analytical results for cesium that exceeded the detection limit – >10,000 ppm Cs (i.e., >1% Cs or >1.06% Cs2O) – of the analytical package. With the overlimit

1 Shaakichiuwaanaan (CV5 & CV13) Mineral Resource Estimate (80.1 Mt at 1.44% Li2O and 163 ppm Ta2O5 Indicated, and 62.5 Mt at 1.31% Li2O and 147 ppm Ta2O5 Inferred) is reported at a cut-off grade of 0.40% Li2O (open-pit), 0.60% Li2O (underground CV5), and 0.80% Li2O (underground CV13) with an Effective Date of August 21, 2024 (through drill hole CV24-526). Mineral Resources are not Mineral Reserves as they do not have demonstrated economic viability.

analytical results now received, the final grade-width calculations for the intervals >1% Cs2O are reported in this news release (see Figure 1, Figure 2, Figure 3, Figure 4, Table 1, and Table 3).

Significant results at CV13 include:

Vega Zone

• 18.1 m at 2.71% Cs2O, including 7.4 m at 5.45% Cs2O (CV24-754).
• 11.1 m at 4.87% Cs2O, including 7.1 m at 7.39% Cs2O (CV24-520).
• 5.7 m at 4.97% Cs2O, including 3.0 m at 8.20% Cs2O (CV24-525).
• 9.6 m at 1.59% Cs2O, including 4.4 m at 2.34% Cs2O (CV24-579).
• 3.0 m at 9.43% Cs2O, including 1.0 m at 22.41% Cs2O (Channel CH23-069).

The largest of the two (2) cesium zones at CV13 is coincident with the high-grade (lithium) Vega Zone (Figure 1) and can be traced through drilling over an extensive area of ~600 m x 400 m, ranging in thickness from 1-2 m to >10 m. The cesium mineralization at the Vega Zone sits ~125 m to 150 m from surface and remains open to the northwest. Additionally, the cesium zone at Vega is commonly accompanied by high-grade lithium and tantalum (Table 1).

Rigel Zone

• 5.9 m at 11.19% Cs2O, including 1.0 m at 22.69% Cs2O (CV23-271).
• 5.0 m at 13.32% Cs2O, including 2.0 m at 22.90% Cs2O (CV23-255).
• 3.2 m at 10.24% Cs2O, including 1.1 m at 26.61% Cs2O (CV23-204).
• 4.5 m at 3.36% Cs2O (CV23-198).

The newly named “Rigel Zone” is situated coincident with the apex of the structural flexure at CV13 and is estimated through drilling to have a high-grade footprint of approximately 200 m x 80 m at up to ~5 m thick. This zone includes the highest cesium grades reported to date from the Property – 1.1 m at 26.61% Cs2O (CV23-204) and 2.0 m at 22.90% Cs2O (CV23-255) – which imply intervals of near-massive pollucite and represent some of the highest known cesium grades reported globally in recent years.

The Rigel Zone is present at shallow depth (~50 m from surface) and, while it appears to be smaller in scale than the Vega Zone, it also appears to be higher grade. Additionally, similar to Vega, the cesium zone at Rigel may be accompanied by high-grade lithium and tantalum (Table 1).

Figure 1: Drill hole analytical result highlights for cesium from the Vega and Rigel zones at the CV13 Pegmatite.

Figure 2: Pollucite in grey quartz matrix from 139.3 m to 139.5 m in drill hole CV24-520 (Vega Zone), within a wider zone of cesium mineralization grading 7.39% Cs2O over 7.1 m.

Figure 3: High-grade pollucite mineralization in drill hole CV23-271 (Rigel Zone) grading 22.69% Cs2O over 1.0 m (64.0 m to 65.0 m).

Figure 4: Semi-massive to massive pollucite intercept (red box) in drill hole CV23-255 (Rigel Zone) grading 17.95% Cs2O over 3.7 m (76.3 m to 80.0 m), including 22.90% Cs2O over 2.0 m (78.0 m to 80.0 m).

CV5 PEGMATITE

In addition to CV13, the CV5 Pegmatite also returned multiple cesium mineralized intercepts (see Figure 5, Figure 6, Figure 7, Table 2, and Table 3). Initial review indicates a wider distribution of cesium across the pegmatite, with distinct zones less apparent compared to the Vega and Rigel cesium zones at the CV13 Pegmatite. However, given the density of drilling, further review and modelling is required to determine continuity and distinct zonation, especially given that cesium zones are relatively small but very high-value. Drill intercept highlights for cesium at CV5 include:

• 10.4 m at 1.30% Cs2O, including 4.0 m at 2.02% Cs2O (CV23-117).
• 9.0 m at 1.20% Cs2O, including 1.5 m at 5.03% Cs2O (CV24-651).
• 7.5 m at 1.29% Cs2O, including 1.5 m at 3.90% Cs2O (CV24-404).
• 2.0 m at 5.24% Cs2O (CV23-219).
• 0.8 m at 13.04% Cs2O (CV24-627).

Figure 5: Pollucite mineralization in drill hole CV23-219 (CV5) grading 5.24% Cs2O over 2.0 m (109.5 m to 111.5 m).

Figure 6: Drill hole analytical result highlights for cesium at the CV5 Pegmatite.

Figure 7: Pollucite mineralization in drill hole CV24-651 (CV5) grading 5.03% Cs2O over 1.5 m (61.0 m to 62.5 m).

Table 1: Cesium assay summary for drill holes at the CV13 Pegmatite (Vega and Rigel Zones).

(1) All intervals are core length and presented for all pegmatite intervals >1 m and >1% Cs2O. (2) Lepidolite may occur with pollucite, although typically in minor amounts, and may contain some cesium in its structure through element substitution; however, it would be significantly less than pollucite. A mineralogy program is underway to more definitively confirm Cs deportment where lepidolite has been logged.

Table 2: Cesium assay summary for drill holes at the CV5 Pegmatite.

(1) All intervals are core length and presented for all pegmatite intervals >1 m and >1% Cs2O. (2) Lepidolite may occur with pollucite, although typically in minor amounts, and may contain some cesium in its structure through element substitution; however, it would be significantly less than pollucite. A mineralogy program is underway to more definitively confirm Cs deportment where lepidolite has been logged.

MINERALOGY AND GEOLOGICAL MODELLING

Pollucite, the principal and preferred ore mineral for cesium, has been identified by XRD mineralogical analysis at Shaakichiuwaanaan and is interpreted to be the primary source of the cesium enrichment at the Property based on cesium grades and logging. The high-grade cesium intercepts indicate that semi-massive to massive pollucite is present, especially in the Rigel Zone where several 10% to 20+% Cs2O intercepts are present. A mineralogical program focused on the Vega and Rigel cesium zones is underway to confirm the presence and quantitative abundance of pollucite, and to a lesser extent lepidolite where present.

With the overlimit assays for cesium now received, the Company is actively geologically modelling the Vega and Rigel cesium zones, both within the wider pegmatite geological model. Additionally, cesium will be added to the block model to further assess the potential of each zone.

In the same way that the Company’s tantalum resource has the potential to be a valuable byproduct, the identification of significant cesium mineralization at CV13 presents an opportunity to further evaluate the potential of cesium as a marketable by-product, which could complement

the Company's lithium-focused development strategy and add to the suite of critical minerals that could be produced at Shaakichiuwaanaan. As the Feasibility Study for CV5 progresses for its lithium operation, the Company will assess the potential for a cesium resource at Shaakichiuwaanaan and its implications for future exploration and development.