Mr. David Park reports

STANDARD LITHIUM REPORTS THIRD QUARTER 2025 RESULTS

Standard Lithium Ltd. has released its financial and operating results for the three- and nine-month periods ended Sept. 30, 2025.

• Released positive definitive feasibility study (DFS) for the South West Arkansas project (SWA project) which continues progressing toward a final investment decision (FID);
• Announced maiden inferred resource for the company's first project in East Texas (Franklin project) containing the highest reported lithium-in-brine grades in North America;
• Completed upsized $130-million follow-on offering on the back of strong institutional investor demand and an oversubscribed order book, following quarter close.

"We had a busy and productive third quarter as we successfully executed on multiple key milestones that we had set out to achieve," said David Park, chief executive officer and director of Standard Lithium. "We released a definitive feasibility study for the SWA project, highlighting the attractiveness and cost-competitiveness of our first commercial project. We also released a maiden inferred resource for our first project in East Texas, the Franklin project. With some of the highest reported lithium-in-brine grades in North America, it provides a strong foundation for future scalable production in the Smackover as we expand our portfolio of high-quality lithium assets.

"Following quarter close, we took a further derisking step by completing a capital raise, supported by strong investor demand, that will put us in a position to reach FID at SWA, as well as progress our Franklin and other projects in East Texas.

"Looking ahead, we expect to provide multiple updates in the coming months as we seek to conclude our ongoing project financing and customer offtake processes, finalize selection of our key SWA project vendors and approve FID before beginning construction at SWA in 2026."

Highlights subsequent to the three-month period ended Sept. 30, 2025

All amounts are in United States dollars unless otherwise indicated. All terms not otherwise defined have the meaning given to them under the CIM (Canadian Institute of Mining) definition standards for mineral resources and mineral reserves.

• Standard Lithium closes upsized $130-million underwritten public follow-on equity offering:
  • Closed an underwritten public offering on Oct. 20 of 29,885,057 common shares at a price of $4.35 per common share for aggregate gross proceeds of approximately $130-million. Strong support received from institutional investors allowed the company to increase the original transaction size by an additional $10-million.
• Smackover Lithium files DFS for its SWA project, North America's highest-grade reported lithium brine reserve:
  • Filed on Oct. 14 following release of the DFS highlights during the third quarter. The SWA project contemplates initial production capacity of 22,500 tonnes per annum of battery-quality lithium carbonate, producing 447,000 tonnes (proven reserves) of lithium carbonate equivalent (LCE), or 38 per cent of the in situ measured and indicated resources of 1,177,000 tonnes LCE. The SWA project will begin production at an average lithium concentration of 549 mg/L (milligrams per litre) and will process 0.20 cubic kilometre of brine over its modelled 20-year life at an average lithium concentration of 481 mg/L.
• Smackover Lithium files maiden inferred resource for its Franklin project in East Texas, containing the highest reported lithium-in-brine grades in North America:
  • Filed on Nov. 5 following release of the highlights during the third quarter. This report for Smackover Lithium's first of three planned projects in the East Texas region of the Smackover highlights the size and quality of its brine position. It marks a key step toward the ultimate goal of reaching production of over 100,000 tonnes of lithium chemicals per year in Texas through multiple phases.
• Smackover Lithium receives key final integration approval from the Arkansas Oil and Gas Commission (AOGC) for SWA project:
  • Received unanimous approval from the AOGC for its integration application for the Reynolds brine unit where the initial commercial phase of the SWA project is planned to be developed. Integration is the formal process which amalgamates any non-leased mineral interests into an approved brine production unit, ensuring the operator's access to the brine while protecting the correlative rights of mineral owners, and is a key derisking step providing certainty on the resource.

Highlights from three-month period ended Sept. 30, 2025

• Smackover Lithium announces positive definitive feasibility study results for its South West Arkansas project:
  • Highlighted by a 20.2-per-cent unlevered pre-tax internal rate of return (IRR), with competitive average cash operating costs of $4,516/tonne and all-in costs of $5,924/t over the operating life, an all-in Class III capex (capital expenditure) estimate of $1.45-billion including a 12.3-per-cent contingency and an upgraded mineral resource. The principal recommendation from the DFS is that the project is ready to progress to an FID. Construction is expected to commence in 2026 shortly after FID, with first production targeted in 2028.
• Smackover Lithium releases maiden inferred resource for its Franklin project comprising a portion of significant brine position in East Texas:
  • Highlighted by 2.2 million tonnes of LCE at an average lithium grade of 668 mg/L, 15.4 million tonnes of potash (as potassium chloride) -- a newly added mineral to the U.S. Geological Survey 2025 Draft Critical Mineral List -- and 2.6 million tonnes of bromide at the inferred resource category. It contains the highest reported lithium-in-brine grades in North America.
• Smackover Lithium reports highest lithium brine grade in SWA project area:
  • Smackover Lithium completed sampling from its newest exploration well, the Lester well, in the SWA project area. One sample recorded the highest lithium concentration reported to date from the SWA project area: 616 mg/L lithium in brine, while average lithium concentration in brine from the Lester well was 582 mg/L. This concluded all subsurface exploration activities for phase 1 of the SWA project.
• Aquatech acquires Koch Technology Solutions' direct lithium extraction business:
  • On Sept. 16, Aquatech announced the acquisition of a portion of Koch Technology Solution's business, including the Li-pro(TM) technology used in our demonstration plant activities and planned for use in the SWA project. As a result of the transaction, Aquatech has assumed Koch's role under existing arrangements with us with no material changes to underlying terms. Further information can be found in the Aquatech press release.
• Expanded leadership team with appointment of general counsel:
  • Appointed Michael Lutgring as general counsel. This addition to the leadership team is critical as the company strengthens its capabilities and bring further expertise in-house and continues its growth and development as a public company.
• Cash and working capital of $32.1-million and $29.0-million, respectively, as of Sept. 30, 2025.
• The company has no term or revolving debt obligations as of Sept. 30, 2025.

Consolidated financial statements

This news release should be read in conjunction with the company's consolidated financial statements and MD&A (management's discussion and analysis) for the three- and nine-month fiscal periods ended Sept. 30, 2025, which are available on the company's issuer profile on SEDAR+ and on EDGAR.

Three-month period ended Sept. 30, 2025, webcast

The company will hold a webcast to discuss its three-month period ended Sept. 30, 2025, on Tuesday, Nov. 11, at 8 a.m. ET. Live access as well as a replay will be available via webcast.

Webcast details

Standard Lithium Q3 2025 earnings call and webcast

Nov. 11, 2025, at 8 a.m. Eastern Time (United States and Canada)

About Standard Lithium Ltd.

Standard Lithium is a leading near-commercial lithium development company focused on the sustainable development of a portfolio of large, high-grade lithium-brine properties in the United States. The company prioritizes projects characterized by high-grade resources, robust infrastructure, skilled labour and streamlined permitting. Standard Lithium aims to achieve sustainable, commercial-scale lithium production via the application of a scalable and fully integrated direct lithium extraction and purification process. The company's flagship projects are located in the Smackover formation, a world-class lithium brine asset, focused in Arkansas and Texas. In partnership with global energy leader Equinor, Standard Lithium is advancing the SWA project, a greenfield project located in Southern Arkansas, and actively advancing a promising lithium brine resource position in East Texas.

We seek Safe Harbor.