Announcement PDF Kachi Phase One DFS Addendum Presentation August 2025 Disclaimers General Statement and Cautionary Statement This presentation has been prepared by Lake Resources N.L. (Lake) for information purposes and not any particular party. The information in this presentation is based upon public information and internally developed data and reflects prevailing conditions and views as of this date, all of which are accordingly subject to change. The information contained in this presentation is of general nature and is not intended to address the circumstances of any particular individual or entity. There is no guarantee that the information is accurate as of the date it is received or that it will continue to be accurate in the future. No warranties or representations can be made as to the origin, validity, accuracy, completeness, currency or reliability of the information. No one should act upon such information without appropriate professional advice after a thorough examination of the particular situation. Lake Resources NL accepts no responsibility or liability to any party in connection with this information or views and Lake disclaims and excludes all liability (to the extent permitted by law) for losses, claims, damages, demands, costs and expenses of whatever nature arising in any way out of or in connection with the information, its accuracy, completeness or by reason of reliance by any person on any of it. The information regarding projects described in this presentation are based on exploration targets, apart from the Kachi project’s resource statement. The potential quantity and grade of an exploration target is conceptual in nature, with insufficient exploration to determine a mineral resource and there is no certainty that further exploration work will result in the determination of mineral resources or that potentially economic quantities of lithium will be discovered. The lithium pegmatite leases occur adjacent to past producers of spodumene but no potential extension to any mineralisation can be assured. Forward Looking Statements Certain statements contained in this presentation, including information as to the future financial performance of the projects, are forward-looking statements. Such forward-looking statements are necessarily based upon a number of estimates and assumptions that, while considered reasonable by Lake Resources N.L. are inherently subject to significant technical, business, economic, competitive, political and social uncertainties and contingencies; involve known and unknown risks and uncertainties and other factors that could cause actual events or results to differ materially from estimated or anticipated events or results, expressed or implied, reflected in such forward-looking statements; and may include, among other things, statements regarding targets, estimates and assumptions in respect of production and prices, operating costs and results, capital expenditures, reserves and resources and anticipated flow rates, and are or may be based on assumptions and estimates related to future technical, economic, market, political, social and other conditions and affected by the risk of further changes in government regulations, policies or legislation and that further funding may be required, but unavailable, for the ongoing development of Lake’s projects. Lake Resources N.L. disclaims any intent or obligation to update any forward-looking statements, whether as a result of new information, future events or results or otherwise. The words “believe”, “expect”, “anticipate”, “indicate”, “contemplate”, “target”, “plan”, “intends”, “continue”, “budget”, “estimate”, “may”, “will”, “schedule” and similar expressions identify forward-looking statements. All forward-looking statements made in this announcement are qualified by the foregoing cautionary statements. Investors are cautioned that forward-looking statements are not guarantees of future performance and accordingly investors are cautioned not to put undue reliance on forward-looking statements due to the inherent uncertainty therein. Lake does not undertake to update any forward-looking information, except in accordance with applicable securities laws. Disclaimers Compliance Statement The information contained in this presentation relating to financial forecasts, production targets, exploration targets, exploration results, Measured, Indicated and Inferred resource estimates, project execution, infrastructure and testing work, has been derived from the information in Lake’s Kachi Project Phase One Definitive Feasibility Update Study Results (“DFS Addendum”) and Lake’s Updated Ore Reserve Statement (“Ore Reserve Update”) both announced on ASX on 4 August 2025 and mineral resource update announced on ASX on 3 June 2025. Lake confirms that it is not aware of any information that materially affects the information included in the DFS Addendum or the Ore Reserve Update both announced on ASX on 4 August 2025 and mineral resource update announced on ASX on 3 June 2025 and all material assumptions contained in those announcements continue to apply and have not materially changed, including all material assumptions underpinning the production targets or forecast information derived from production target, and all technical parameters underpinning the estimates of mineral resource and ore reserves. On this basis, Lake confirms that the findings of Mr. Andrew Fulton, the Competent Person, in the DFS Addendum and the Ore Reserve Update both announced on ASX on 4 August 2025 and, in respect of Lake’s mineral resource, in the mineral resource update announced on 3 June 2025, have not changed nor been modified in any material respects since those announcements. Hatch Disclaimer The DFS Addendum was prepared by Hatch Ltd. (“Hatch”), together with certain other consultants (the “Other Consultants”), for the sole and exclusive benefit of Lake Resources N.L. (the “Principal”) for the purpose of undertaking a study for the Kachi Project (“Project”), and may not be provided to, relied upon or used by any other party. This DFS Addendum summary report was created by the Principal to summarize material and key matters from the DFS Addendum. The use of the DFS Addendum by the Principal is subject to the terms of the relevant services agreement between Hatch and the Principal. This DFS Addendum summary report is meant to be read as a whole, and sections should not be read or relied upon out of context. The DFS Addendum summary report includes information provided by the Principal, the Other Consultants and by certain other parties on behalf of the Principal. Unless specifically stated otherwise, Hatch has not verified such information and does not accept any responsibility or liability in connection with such information. In particular, Hatch does not accept any responsibility or liability in connection with the sections of this DFS Addendum summary report that have been prepared by the Principal or by the Other Consultants. This DFS Addendum summary report contains the opinion of Hatch using its professional judgment and reasonable care, based upon information available at the time of preparation. The quality of the information, conclusions and estimates contained in the report are consistent with the intended level of accuracy as set out in this report, as well as the circumstances and constraints under which this DFS Addendum summary report was prepared. As the DFS Addendum is a feasibility study and the DFS Addendum summary report is a summary of a feasibility study updates, all estimates and projections contained in this DFS Addendum summary report are based on limited and incomplete data. Accordingly, while the work, results, estimates and projections in this DFS Addendum summary report may be considered to be generally indicative of the nature and quality of the Project, they are not definitive. No representation or prediction in this DFS Addendum summary report is intended as a guarantee of the results of future work, and Hatch does not promise that the estimates and projections in this DFS Addendum summary report will be realized this information in the form and context in which it appears. The information in this announcement is an accurate representation of the available data from initial exploration at the Kachi Project as prepared by Mr. Fulton. Executive Summary DFS Update DFS Addendum delivers significant project improvements Positive Updates Since Original DFS ✓ Higher brine grades – 249 mg/L Design Basis ✓ DLE technology improvements ✓ New high-quality resource and reserve data ✓ Well development and construction efficiencies DFS Addendum Financial Highlights ▪ ▪ ▪ ▪ US$1,157M Capex US$5,895/t Opex US$1.5B Pre-Tax NPV10 22.5% Pre-Tax IRR ✓ Completed power supply FEED ✓ 2023 Completed Kachi Phase 1 DFS 2024 - 2025 ✓ Completed Value Engineering Study 2025 ✓ Completed DFS Addendum with Hatch Engineering 5 DFS Update Key drivers of DFS Addendum Results Higher Brine Grade Improved DLE Technology Reduced Footprint and Reagent Use Stronger Project Economics • • • Updated average lithium concentration increased from 205 mg/L (Original DFS) to >250 mg/L1 DFS Addendum design basis set at 249 mg/L, enabling more efficient lithium extraction Average lithium concentration further increased to 268 mg/L2 indicating additional realizable improvements beyond those achieved in the DFS Addendum • • • Transition to Lilac Gen4 Ion Exchange (IX) technology3 Recovery rates increased from ~80% to ~90% Greater throughput, longer IX media lifecycle, and fewer IX modules required resulting in a 39% lower DLE Capex and 40% lower DLE Opex • • • • • ~22% reduction in number of wells representing 35% and 44% improvement in well Capex and Opex, respectively ~50% reduction in number of DLE modules ~15-20% reduction in plant footprint4 Reduced brine pumping requirements resulting from higher brine grades and improved flow rates Significantly lower reagent consumption • • • Lower capital intensity and improved operational efficiency Engineering improvements offset inflationary pressures Robust project IRR and NPV 1 Refer to ASX announcement dated 3 June 2025. 2Refer to ASX announcement dated 4 August 2025 – Updated Lithium Ore Reserve. The following cost savings are realized on the design basis of 249 mg/L. 3Refer to Lilac Solutions’ announcement and Technical White Paper dated 25 June 2024 about its latest generation lithium extraction technology. 4With enhanced lithium content and advanced processing efficiencies, the plant's physical footprint is reduced while maintaining planned production capacity. 6 Kachi Phase 1 DFS Addendum Results 1 REDUCED CAPEX • • • Capex now US$1,157M, representing ~US$220M improvement from Original DFS figures1 Represents a 19% improvement from the inflation adjusted baseline1 or a 16% improvement from Original DFS Further Capex reduction achievable due to improved brine concentration of 268 mg/L 2 2 REDUCED OPEX • • • Meaningful improvement in Opex to US$5,895/t LCE, still one of the lowest on the industry cost curve Represents a 3% improvement from Original DFS numbers Further Opex reduction achievable due to improved lithium brine concentration to 268 mg/L2 3 ROBUST FINANCIALS • Estimated NPV10% at US$1,469M pre-tax and US$1,011M post-tax based on Benchmark Mineral Intelligence (BMI) Q2 2025 average price of ~US$20,500/t3 for battery grade lithium carbonate over life of mine Estimated IRR at 22.5% pre-tax and 19.7% post-tax 4.5-year payback period 4 REDUCED EXECUTION RISK • • • • • • • • • • Plant design basis updated to 249 mg/L to reflect improved lithium concentration4 Measured resource increased from 3.0 to 4.2 Mt LCE, total resource increased from 10.6 to 11.1 Mt LCE4 Single phase5 plant construction approach now utilized Critical de-risking milestone for grid power – YPF-Luz completed FEED for Kachi power connection in May 2025, reflecting a betterunderstood, executable, and technically viable power solution6 Next generation DLE technology Benign brine chemistry eliminates costly pre-treatment, enhancing project economics Improved modularization for increased off-site fabrication, reducing field labour and site construction risk EIA final approval expected in 2025 1 The 2023 DFS capital cost estimate of US$1.38 billion was escalated to US$1.42 billion to reflect prevailing inflationary indices as of February 2025, before being optimized to US$1.16 billion following the value engineering study using 249mg/L design basis. The capital cost values have not been static positions while quantities, durations, power loadings and filed layouts (amongst other things) have remained under review. The February 2025 capital cost of US$1.42 billion was only determined during the course of value engineering work undertaken to calculate the updated capital cost figure contemplated in this presentation. This applies to each reference to the US$1.42 billion capital cost figure in this presentation. 2 Refer to ASX announcement dated 4 August 2025 – Updated Lithium Ore Reserve. 3 Based on BMI Q2 2025 Lithium Price Forecast available via Lake Resources annual paid subscription. 4Refer to ASX announcement dated 3 June 2025. To remain consistent with the environmental permitting, the well locations for unutilized wells have not been moved. 5 In the 2023 DFS, a two-phased construction philosophy was implemented due to the lack of grid power available early in the project's life. However, this approach is now considered unnecessary, and a single-phase construction approach will be utilized instead. 6Refer to ASX Announcement dated 2 July 2025. 7 Significant milestones achieved in 2025 following successful 2023 and 2024 execution 2023 and 2024 Accomplishments ✓ Successfully completed demo plant – processed 5.2 million litres of brine and produced more than 1,300kg of >99.5% purity lithium carbonate ✓ Kachi Phase One DFS Completed1 ✓ Initiated Strategic Partnering Process2 ✓ Submitted Environmental Impact Assessment (EIA)3 ✓ Signed Letter of Intent (LOI) with YPF-Luz for power supply4 ✓ Right-sized business and cost structure to reflect current scope of activities 2025+ Key Objectives ✓ Launched Kachi Strategic Review5 ✓ JORC Update Increasing Total Resource to 11.1 Mt LCE6 ✓ Completed Internal Capex and Opex Value Engineering Study ✓ Ore Reserve Statement Confirms 268 mg/L Lithium Grade7 ✓ Completed Power Supply FEED8 ✓ Completed Kachi Phase 1 DFS Addendum o Obtain EIA Approval o Complete Kachi Strategic Review o Continue to optimize technical and commercial power solutions o Work towards FID 1 Refer to ASX announcement dated 19 December 2023. 2 Refer to ASX announcement dated 29 November 2023. 3 Refer to ASX announcement dated 26 March 2024. 4 Refer to ASX announcement dated 6 May 2024. 5 Refer to ASX announcement dated 7 May 2025. 6 Refer to ASX announcement dated 3 June 2025. 7 Refer to ASX announcement 4 August 2025 – Updated Lithium Ore Reserve 8 Refer to ASX announcement dated 2 July 2025. 8 1. Improved Capex 1 IMPROVED CAPEX DFS Addendum Capex estimates reduced by 16% compared to Original DFS figures Capex Optimization (US$) $1,377M Key Drivers of Capex Reduction (US$) ▪ DFS Design basis improved from 205 mg/L to 249 $1,423M mg/L $46M ▪ Slight increase in Capex estimates reflects -$266M $1,157M inflationary adjustments to labour and equipment ▪ Higher brine feed grade, and improved IX media Original DFS Capex Increase 2025 Inflation Adjusted Capex Savings DFS Addendum Capex Updated Wellfield Development Plan Lithium Concentration Well Count 2023 DFS 205 mg/L 37 wells – 21 production, 16 injection DFS Addendum 2025 DFS Addendum Design Basis 249 mg/L 29 wells – 13 production, 16 injection 268 mg/L 25 wells – 11 production, 14 injection 2025 Ore Reserve1 1 Refer to ASX announcement dated 4 August 2025 – Updated Lithium Ore Reserve. performance led to: ▪ Reduction in DLE modules reduced major equipment, civil works and installation costs of ~$98M in savings ▪ Optimized piping specification – swapping PEX for HDPE – saved $45M ▪ Mechanical equipment modification due to improved feed rates, smaller plant footprint resulted in $39M savings ▪ Strategic shift to higher-grade wells and greater efficiency resulting in $31M savings ▪ Other efficiencies including, downsizing reagent storage, handling and dosing systems, efficient construction plan, elimination of interim costs and updated vendor pricing resulted in additional $53M savings 10 1 IMPROVED CAPEX Direct Lithium Extraction technology (Gen 4) improvements Lilac Gen 4 Ion Exchange The Kachi DFS Addendum incorporates improvements from Lilac’s Gen 4 lithium extraction technology, which was launched in June 2024. This latest generation delivers significant performance improvements that enhance project economics and sustainability: Original DFS (Gen 3 Lilac IX) DFS Addendum (Gen 4 Lilac IX) Lithium Recovery 80% 90% Impurity Rejection 99.9% 99.9% Product Lithium Concentration (mg/L) 2,280 2,320 ◼ Improved throughput and system design: 50% fewer IX modules are now required, enabling a more compact system layout and driving 39% lower capital cost for the IX package Cycle Life 2,200 4,300+ ◼ Proven in the field: Gen 4 technology was successfully demonstrated at Lilac’s Jujuy plant with similar brine, exceeding the commercial design basis IX Modules 8 4 ◼ Lithium recovery rates increased from 80% to 90%. Combined with increased brine grade, this improvement reduces the volume of feed and reinjection brine needed by 30% to meet plant capacity, thereby improving process efficiency and supporting higher reserve estimates ◼ Impurity rejection of 99.9% ensures high-purity eluate, reducing downstream processing complexity and cost ◼ Extended IX media durability significantly increases ion exchange media lifespan, reduces replacement frequency and lowers reagent use by up to 70% ◼ Environmental and operational benefits: Gen 4 reduces water consumption by 32%, supporting Kachi’s environmental sustainability objectives and lowering associated utility and infrastructure costs 11 1 IMPROVED CAPEX ▪ The Original DFS two-phase strategy was driven by uncertainties around timely grid power availability, forcing reliance on diesel and solar power to accelerate first lithium production in Phase 1A and delaying the power-intensive Chlor-Alkali plant until Phase 1B ▪ ▪ Optimised construction schedule accelerates Kachi’s commissioning by six months Introduced higher reagent and power costs via added Capex for interim processing and temporary power systems for Phase 1A The DFS Addendum reflects a more streamlined and capital-efficient approach enabled by key shifts in project timing and power availability ▪ Grid power availability now expected to coincide with hook-up and commissioning activities ▪ Onsite commissioning of the Chlor-Alkali plant at handover enables in-house reagent production from Day 1 ▪ Eliminates redundancy – interim processing and temporary power systems New Project Development Timeline Project Schedule Improvements Original DFS DFS Addendum FID to Mechanical Completion 33 months 30 months FID to First Lithium 33 months 33 months FID to Operation Handover 48 months 42 months Grid Power Available 36 months 30 months 12 2. Improved Opex 2 IMPROVED OPEX Kachi’s US$5,895/t Opex places it among the lowest-cost brine projects globally Run-rate Operating Expense Categories Summary of operating cost estimates1 Maintenance Consumables 4% 2% Labor 5% ▪ Utilities2 is the largest contributor to Opex with grid power expenses being the most significant factor (accounting for 55% of Opex) G&A ▪ Next largest contributors are DLE costs and 7% reagents cost (offset by a by-product credit for excess sodium hydroxide and sodium hypochlorite production) ▪ Opex estimate is for typical operating year after US$5,895 / tonne Reagents 12% ramp-up 57% Utilities 13% Lilac 1Estimated operating costs are based on February 2025 estimates adjusted for inflation using US Consumer Price Index. 2Utilities made up of power and water. 14 2 IMPROVED OPEX Achieved 28% reduction in non-utilities Opex compared to Original DFS Opex Optimization (US$/t) Key Drivers of Opex Reduction ($508) Improvements $828 $6,047 $122 ($108) $8 ($76) ($270) $5,895 ($236) $184 ($96) Original Reagents DFS Maint. Utilities Lilac DLE Labour Consumables G&A Wells 1 NaCIO NaOH DFS By-product By-product Addendum Credits Credits Opex DFS Addendum -3% $6,047 -28% +32% $3,496 $2,516 Non-Utilities $2,551 $5,895 Increases in unit cost of sodium carbonate but partially offset via by-product credits ▪ Utilities: ~98% increase in grid power $3,379 Utilities demand ▪ Maintenance: ~4% increase ▪ Reagents: ~13% increase driven by rise Opex Breakdown Between Utilities & Non-Utilities (US$/t) Original DFS -3% ▪ DLE Technology: ~40% decrease ▪ G&A: ~40% decrease ▪ Consumables: ~41% decrease ▪ Labour: 27% decrease ▪ Utilities: 31% decrease in power MW unit rate partially offset by 31% decrease in MW consumed Total Opex 1The wellfield sustaining cost (i.e., workover costs) calculation for the DFS Update are included in the project economic model as opposed to the Opex estimate costs. 15 2 IMPROVED OPEX YPF-Luz power FEED provides technical solution for grid power access Continuous optimization of technical and commercial power solutions up to FID Kachi Power Consumption1 Grid Power Line – Potential Lithium Projects2 82 MW 25 MW ▪ -31% 57 MW 8 MW Solar 48 MW Grid 2023 DFS Savings 2025 DFS Addendum Improved technology, resource quality, and value engineering have significantly reduced Kachi plant power consumption from 82MW to 57MW ▪ The 270 km line powering Kachi is expected to be built in two phases: Leg #1 ET La Puna in the north to ET #2 SHM (Hombre Muerto); and Leg #2 - ET #2 SHM to ET #3 Kachi in the south ▪ DFS Addendum pro-forma power costs assume Kachi will carry (on a MWh basis) a significant portion of the capital costs of Leg #1 and 100% of Leg #2, materially impacting total Opex ▪ Kachi’s power costs can potentially be reduced by adding additional users to the power line, and/or via alternative power solutions including geothermal, solar and trucked LNG ▪ Discussions are ongoing with YPF-Luz as Lake seeks to achieve the lowest cost power solution for Kachi 1Does not include potential reduction in power consumption resulting from updating plant design basis to 268mg/L. 2Map developed internally and project locations are based on knowledge of Lake employees and consultants. 16 3. Robust Financials 3 ROBUST FINANCIALS Kachi economics to be positively impacted from Argentina’s new Incentive Regime for Large Investments (RIGI) RIGI Incentives Considered for Kachi Economic Analysis1  25% Corporate Income Tax flat rate  Accelerated depreciation  0% export duties after year three of obtaining RIGI approval  No customs duties on imports  Foreign currency from financing will not be subject to restrictions Several Recent RIGI Authorizations ▪ Argentina’s authorization of Rio Tinto’s US$2.5B Rincon project—the inaugural approval under the RIGI incentive regime—signals a transformative shift for lithium investors ▪ Galan Lithium’s Hombre Muerto West lithium project was also approved for RIGI by the Argentine government, bringing the total number of RIGIapproved projects to six ▪ RIGI offers 30 years of regulatory stability, tax and customs benefits, and international arbitration rights, thereby enhancing confidence and accelerating capital deployment in the region ▪ Lake assumes Kachi can apply for the RIGI concessions in a timely manner 1Based on provisions of Argentina RIGI Law that was passed in 2024 for qualified capital projects that invest more than $200M in Argentina. Final terms are subject to extension of RIGI deadline to July 2027 and the outcome of direct negotiations between the Kachi Project and the Argentine Government throughout the application process. 18 3 Long-term robust lithium demand projections with 10% CAGR through 2035 ROBUST FINANCIALS Lithium demand is expected to roughly double over the next five years, although the market is expected to be oversupplied over the same period However, significant demand growth is anticipated to induce market shortfall beginning in 2029 Lithium Demand (BMI Q2 2025 Forecast) Lithium Supply and Demand Balance Forecast Total Supply (LHS) 2025-2035 CAGR = 10% 5,000 450 (‘000 LCE) 2,710 2,500 2,000 1,500 1,366 1,000 350 3,500 300 3,000 250 2,500 150 200 100 2,000 50 0 1,500 -50 -100 1,000 -150 -200 500 500 0 400 Deficit / Surplus (t LCE) +98% Supply / Demand of Lithium (t LCE) 4,000 3,000 500 4,000 4,158 3,500 Deficit (RHS) 4,500 +53% 4,500 Total Demand (LHS) -250 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 Source: BMI Q2 2025 Lithium Forecast. Note: The Company does not verify the accuracy of information derived from BMI or from other company presentations or reports. 0 -300 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 19 3 ROBUST FINANCIALS Average price of ~US$20.5k/t over LOM based on BMI Q2 2025 forecasts for battery grade lithium carbonate Price Forecast for Battery Grade Lithium Carbonate (US$/t) BMI Annual Price Forecast for Battery Grade Lithium Carbonate $28,000 Average Price over Life of Mine $26,000 Production Phase $24,000 $22,000 $20,000 $20,460/t $18,000 $16,000 $14,000 $12,000 Construction Phase $10,000 conservative price forecast compared to Original DFS ▪ The forecasted lithium prices are used to estimate project revenues. Notably, prices in the first three years of production (years 1-3) are significantly below the average LOM price of ~US$20,500 ▪ The lower prices in the early years reduce forecast revenues and Project cashflows ▪ BMI forecasts that lithium $8,000 carbonate prices will recover from ~US$9,000/t in 2025 to US$21,000/t by 2031, as structural supply deficits emerge post-2029 $6,000 $4,000 $2,000 $0 ▪ Significantly more Yr-2 Yr-1 Yr0 Yr1 Yr2 Yr3 Yr4 Yr5 Yr6 Yr7 Yr8 Yr9 Yr10 Yr11 Yr12 Yr13 Yr14 Yr15 Yr16 Yr17 Yr18 Yr19 Yr20 Yr21 Yr22 Yr23 Yr24 Yr25 Source: BMI Q2 2025 Lithium Forecast. Notes: The Company does not verify the accuracy of information derived from Benchmark Mineral or from other company presentations or reports. 20 3 ROBUST FINANCIALS Robust financial results Targeted project financial results1 ($US) ($USD) Units Period Original DFS DFS Addendum Lithium Carbonate Revenue $M Life of Mine 20,700 12,837 Lithium Carbonate Revenue $M Annual Average 827 513 EBITDA2 $M Life of Mine 15,870 9,031 EBITDA2 $M Annual Average 635 361 EBITDA Margin % Run Rate 76% 71% Net Profit After Tax $M Life of Mine 8,959 5,771 Opex $/t Run Rate 6,047 5,895 Total Capex $M 1,377 1,157 NPV8 Pre-Tax $M 3,854 - NPV8 Post-Tax $M 2,333 - NPV10 Pre-Tax4 $M - 1,469 NPV10 Post-Tax4 $M - 1,011 IRR Pre-Tax % 25.4 22.5 IRR Post-Tax % 20.9 19.7 Total Free Cashflows (Post-Tax) $M 9,310 6,794 Payback Period (Post-Tax) Years 4.5 4.5 Drop in project economics compared to 2023 DFS are driven by significantly lower forecast lithium price curve and 10% discount rate4 DFS Addendum – 25 ktpa LCE Production Target3 $527M Annual Lithium Carbonate Revenues $1.5B 22.5% Pre-Tax NPV10 Pre-Tax IRR $361M $1.01B 19.7% Annual Average EBITDA2 Post-Tax NPV10 Post-Tax IRR 25 years $1.16B $5.9/kg Life of Mine Capital Cost Run Rate Operating Cost Note on Discount Rate: The Original DFS applied an 8% real discount rate, consistent with industry norms and aligned with the methodologies used by peer lithium developers at the time. In this updated DFS Addendum, we have adopted a 10% real discount rate. This change reflects our commitment to a more conservative and disciplined financial approach, aligns with current market expectations and provides a more robust, risk-adjusted view of the Kachi Project’s economic resilience Life of Mine 1 Economics based on average price of ~$20,500 per tonne LCE over the LOM, derived from forward price projection provided by BMI in their Q2 2025 lithium price forecast, available via annual subscription. 2 Please see “Non-GAAP Financial Measures” in the appendix. Results reflect the impact of Argentina’s RIGI concessions on corporate income tax, export duties and accelerated depreciation. Final terms are subject to extension of RIGI deadline to July 2027 and the outcome of direct negotiations between the Kachi Project and the Argentine Government throughout the application process. 3Refer to ASX announcement dated 4 August 2025, “Kachi Phase One Lithium Brine Definitive Feasibility Study Addendum” for full details regarding material assumptions relied upon. Lake confirms the material assumptions in that announcement continue to apply and have not materially changed. 4 See Appendix for peer data on discount rate and “Non-GAAP Financial Measures”. 21 3 ROBUST FINANCIALS Sensitivity analysis shows Kachi is highly resilient to Capex and Opex variations Post-Tax NPV10 Sensitivities Chart (-15% / +15%; Base $1,011M) ($US) Lithium Price ($17.40k - $20.50k - $23.50k) 41.4% Capital Expenditure ($1.33B - $1.16B - $0.98B) Operating Expenditure ($6,779/t - $5,895/t - $5,011/t) Notes: Assumes + /- 15% sensitivity on post-tax NPV10 and IRR. 41.1% Post-Tax IRR Sensitivities Chart (-15% / +15%; Base 19.7%) ($US) Lithium Price ($17.39k - $20.5k - $23.53k) 15.0% Capital Expenditure ($1.33B - $1.16B - $0.98B) 12.0% 12.0% Operating Expenditure ($6,779/t - $5,895/t - $5,011/t) 15.0% 18.8% 17.5% 11.5% 5.4% 15.2% 5.7% 22 4. Reduced Risk 4 REDUCED RISK Resource size increased 12% to 11.1 million Mt LCE Kachi