Standard Lithium Files Preliminary Base Shelf Prospectus

The Shelf Prospectus has not yet become final for the purpose of the sale of securities. When final, the Shelf Prospectus would allow the Company to make offerings of up to US$250,000,000 of common shares, preferred shares, warrants, subscription receipts, units, debt securities, or any combination thereof, from time to time over a 25-month period. The specific terms of any future offering of securities (if any) will be set forth in a supplement to the Shelf Prospectus. The Company has filed the Shelf prospectus for future financial flexibility and has no immediate intentions to undertake an offering. As reported in its quarterly financial statements for the period ending March 31, 2021, the Company had a cash position of C$30.26 million and is debt free with the early conversion of a loan facility by LANXESS Corporation. Management believes the filing of the Shelf Prospectus provides the Company with flexibility to pursue various strategic initiatives in accordance with the Company's growth strategy.

Robert Mintak, Chief Executive Officer of the Company, commented "The Company has consistently demonstrated a disciplined approach to capital allocation and is well funded for our upcoming milestones with no immediate plans to raise capital through this filing. With our recent listing to the NYSE American the filing of the Shelf Prospectus is a natural step for the Company."

In connection with finalization of the Shelf Prospectus, the Company intends to file a corresponding registration statement on Form F-10 with the United States Securities and Exchange Commission in accordance with the Multijurisdictional Disclosure System established between Canada and the United States.

This news release shall not constitute an offer to sell, or a solicitation of an offer to buy, any securities nor shall there be any sale of securities in any jurisdiction in which an offer, solicitation or sale would be unlawful prior to registration or qualifications under the securities laws of any such jurisdiction.

A copy of the Shelf Prospectus is available under the profile for the Company on SEDAR (www.sedar.com).

About Standard Lithium Ltd.

Standard Lithium is an innovative technology and lithium development company. The Company's flagship project is located in southern Arkansas, where it is engaged in the testing and proving of the commercial viability of lithium extraction from over 150,000 acres of permitted brine operations. The Company has commissioned its first-of-a-kind industrial-scale direct lithium extraction demonstration plant at Lanxess's south plant facility in southern Arkansas. The demonstration plant utilizes the Company's proprietary LiSTR technology to selectively extract lithium from Lanxess's tail brine. The demonstration plant is being used for proof-of-concept and commercial feasibility studies. The scalable, environmentally friendly process eliminates the use of evaporation ponds, reduces processing time from months to hours and greatly increases the effective recovery of lithium. The Company is also pursuing the resource development of over 30,000 acres of separate brine leases located in southwestern Arkansas and approximately 45,000 acres of mineral leases located in the Mojave Desert in San Bernardino county, California.

Standard Lithium is listed on the TSX Venture Exchange and the NYSE American under the trading symbol "SLI"; and on the Frankfurt Stock Exchange under the symbol "S5L". Please visit the Company's website at www.standardlithium.com.

On behalf of the Board of Standard Lithium Ltd.

Robert Mintak, CEO & Director

For further information, contact Anthony Alvaro at (604) 240 4793

Twitter @standardlithium

LinkedIn https://www.linkedin.com/company/standard-lithium/

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release. This news release may contain certain "Forward-Looking Statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995 and applicable Canadian securities laws. When used in this news release, the words "anticipate", "believe", "estimate", "expect", "target, "plan", "forecast", "may", "schedule" and other similar words or expressions identify forward-looking statements or information. These forward-looking statements or information may relate to timing, size and type of future offerings under the Shelf Prospectus (if any), future prices of commodities, accuracy of mineral or resource exploration activity, reserves or resources, regulatory or government requirements or approvals, the reliability of third party information, continued access to mineral properties or infrastructure, fluctuations in the market for lithium and its derivatives, changes in exploration costs and government regulation in Canada and the United States, and other factors or information. Such statements represent the Company's current views with respect to future events and are necessarily based upon a number of assumptions and estimates that, while considered reasonable by the Company, are inherently subject to significant business, economic, competitive, political and social risks, contingencies and uncertainties. Many factors, both known and unknown, could cause results, performance or achievements to be materially different from the results, performance or achievements that are or may be expressed or implied by such forward-looking statements. The Company does not intend, and does not assume any obligation, to update these forward-looking statements or information to reflect changes in assumptions or changes in circumstances or any other events affections such statements and information other than as required by applicable laws, rules and regulations.