Lithium Australia granted Australian patent for SiLeach® lithium extraction technology

Lithium Australia NL (ASX:LIT) (OTCMKTS:LMMFF) (FRA:3MW) has received a standard patent ‘Certificate of Grant’ from IP Australia for its SiLeach® extraction technology for low-energy recovery of lithium from micas – potentially a short-cut in the production of lithium-ion batteries.

The SiLeach® process can produce a range of lithium chemicals, including lithium carbonate and lithium phosphate (Li3PO4) which is the shortest route to the production of lithium ferro phosphate (LFP) batteries, and is also advantageous from an environmental, social and governance perspective.

To date, the company has lodged patent application PCT/AU2017/050104 for the first-generation SiLeach® technology in the following jurisdictions.

• Australia – patent granted (Patent number 2017218457);
• USA – patent granted (Patent number 10,883,157,B2);
• Chile – ongoing examination;
• Europe – claims allowed and intention to grant issued;
• Brazil – request for examination filed; and
• Canada – under accelerated examination.

“Patent grant timely”

Lithium Australia managing director Adrian Griffin welcomed the patent: “[The] granting of the Australian SiLeach® patent is timely, given increased interest in the extraction of lithium from clays in North America, and even more so now that Chinese LFP production in the March 2021 quarter alone almost eclipsed the entire 2020 production.

“The lithium and phosphorus required to manufacture LFP are both produced by SiLeach® as a single lithium chemical.

“It has been shown that the lithium phosphate product from SiLeach® can be directly used in the manufacture of LFP cathode powder

“We invite anyone with a lithium mica or clay deposit to reach out and see what we can offer; also, those cathode producers interested in discussing a more direct route to LFP synthesis using our proprietary VSPC cathode powder production technology.”

Reduced processing steps

SiLeach® offers significant advantages over competing processes, particularly with the recovery of lithium from low-tenor solutions, which minimises the capital cost of evaporators and the high energy costs associated with evaporation.

Direct precipitation of lithium as a phosphate, and its subsequent refining, provides the potential for direct feed into the production of LFP cathode powders.

The company, through its 100%-owned subsidiary VSPC Ltd, has produced LFP cathode powder from tri-lithium phosphate generated via the SiLeach® process – which was subsequently used to manufacture battery cells for testing, with positive results.

Supply of tri-lithium phosphate to LFP producers eliminates the requirement for lithium hydroxide or lithium carbonate in some of the LFP production processes, shortening the supply chain.

Pilot plants and R&D

Two generations of SiLeach® pilot plants have been operated successfully at the Australian Nuclear Science and Technology Organisation (ANSTO) facility at Lucas Heights in New South Wales.

LIT is continuing R&D with ANSTO with a focus on low-grade and waste materials such as lithium micas, fine spodumene and spent LIBs.

The production of lithium phosphate is a common thread in these technologies because it is a key ingredient in the production of LFP cathode powder – which will power Tesla 3 electric vehicles (EVs).

LFP is a much safer alternative compared to more conventional LIB chemistries and is cheaper to produce.

The company is confident that demand from Chinese EV makers for LFP will continue to grow, with BYD (a leading Chinese producer of LIBs) recently increasing its LFP production to meet anticipated demand.

Second-generation patent application

The company has received a written opinion from the International Searching Authority on the patentability of Patent application PCT/AU2019/050541 (detailing the second-generation SiLeach®), confirming that the claims are novel and inventive.

This application has been lodged in the following jurisdictions.

• Australia – national phase entry has commenced and awaiting examination;
• USA – under examination;
• Chile – accepted into examination;
• Europe – under examination;
• Brazil – national phase entry has commenced and awaiting examination; and
• Canada – national phase entry has commenced and awaiting examination.

Story by ProactiveInvestors