The investment helped validate Standard Lithium's direct extraction technology and "couldn't have come at a better time," Canaccord Genuity analyst Katie Lachapelle said, noting the company's recovery results were criticised in a short-seller's report last week.

Standard Lithium had rebuffed the Blue Orca Capital report, saying it had misunderstood data and contained numerous inaccuracies.

It said KSP, a subsidiary of private company Koch Investments Group, would receive almost 13.5 million shares priced at C$9.43, a 15% discount to the previous day's close.

"KSP has an impressive track record of investing in disruptive technologies and their backing is an important endorsement of the company's core technology, development plans and of our intent to make the Gulf Region a leading supplier of lithium resources," Standard Lithium CEO Robert Mintak said.

The company said the proceeds would be used to rapidly advance the first commercial project proposed for the Lanxess facility, accelerate development at its South West Arkansas lithium project, work collaboratively with Koch and allow for strategic project expansion.

KSP president David Park said it was an exciting time for energy transformation and KSP believed its investment could help accelerate lithium production in the US.

Canaccord pointed out Koch had made a number of investments in EV value chain-related businesses over the past year.

"We believe this strategic investment should give investors confidence as it follows extensive due diligence by Koch into SLI's technology and the company's development plans," Lachapelle said.

Canaccord maintained a speculative buy rating and target price of $14.

Standard Lithium shares (TSXV: SLI) were trading about $2.60 at this time last year and reached a high of $15.92 less than a month ago.

They closed up 22.2% to $13.55 yesterday, capitalising it at $1.99 billion (US$1.6 billion).