Mr. Dan Rosen reports

SMACKOVER LITHIUM REPORTS HIGHEST LITHIUM BRINE GRADE IN SWA PROJECT AREA AS FEED STUDIES NEARING COMPLETION

Smackover Lithium, a joint venture between Standard Lithium Ltd. and Equinor, has completed sampling from its newest exploration well, the Lester well, in the southwestern Arkansas project area, and has recorded the highest lithium concentration reported to date from the SWA project area: 616 milligrams per litre lithium in brine.

The Lester well was completed in the second quarter of this year and concludes all subsurface exploration activities for phase 1 of the SWA project.

Sampling of brines from the upper Smackover formation was completed by the company, and subsequent analysis of the brine by an independent third party certified laboratory demonstrated significantly higher-than-expected lithium concentrations in the Lester brine, marking the highest lithium grade reported for the SWA project. The summarized lithium brine analyses are provided in Table 1 below, highlighting the average lithium concentration from three brine samples was 582 mg/l.

Dr. Andy Robinson, president and chief operating officer of Standard Lithium, stated: "The Smackover Lithium team has now completed all the fieldwork and testing required for phase 1 of the SWA project. We completed this final well in a part of the project area where we expected the lithium concentration to be approximately 500 mg/l, so we're encouraged with these latest sampling results that show the highest lithium concentrations in the whole SWA project area (maximum 616 mg/l), demonstrating a marked improvement from levels in the existing world-class lithium brine resource.

With all of the fieldwork complete, the joint Smackover Lithium team is working to complete the FEED study, with a definitive feasibility study expected later in the third quarter of this year. The completion of these studies will represent a significant milestone as the team rapidly advances phase 1 of the SWA project through offtake negotiations and project finance towards a final investment decision targeted by year-end 2025."

Qualified person

Steve Ross, PGeol, a qualified person as defined by National Instrument 43-101, has reviewed and approved the relevant scientific and technical information that forms the basis for this news release. Mr. Ross is a consultant to the company.

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 through 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 ASA, Standard Lithium is advancing the southwestern Arkansas project, a greenfield project located in southern Arkansas, and actively exploring promising lithium brine prospects in east Texas. Standard Lithium trades on both the TSX Venture Exchange and the NYSE American under the symbol SLI.

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