Perth's Talga makes Li-ion battery breakthrough

Perth-based advanced materials company Talga Resources’ preparation of graphite for the Li-ion battery eliminates a number of processing steps otherwise required under conventional graphite refining pathways to meet commercial-level performance in capacity over 100 cycles in a cell test. 

The company announced encouraging results from initial lithium-ion battery testwork using anode graphite sourced from its Vittangi project in Sweden. The early-stage test outcomes are significant as the results match battery makers’ emerging requirements for lower cost and more environmentally sensitive manufacturing processes.

Talga has been closely examining the energy storage market for some period. Previously, the company held the view that its focus in energy storage should be directed solely to next-generation batteries that are enhanced with graphene — this view has now been expanded.

Today’s Li-ion market relies on graphite anodes that are supplied from costly synthetic or natural large flake graphite products. Given that spherical graphite for use in Li-ion battery anodes ends up being very small (it is micronised), Talga has been investigating the use of its unmilled ultrafine flake graphite particles from its Vittangi graphite deposit (that are naturally this scale already). The objective being to form a Li-ion battery anode with the least number of processing steps while attaining industry-standard energy capacity.

Ordinarily, natural graphite cannot be used in Li-ion battery anode material without extensive physical and chemical refining. In this testwork, Talga’s unpurified graphite (natural <10 microns grading 93% Cg purity) was used directly as the active anode material without any micronising, spheroiding and coating steps used currently by industry.

Talga micrographite used as active material enabled the battery to achieve first charge capacity of 375 mAh/g, a first discharge capacity of 481 mAh/g and average charge capacity over 100 cycles of 357 mAh/g. The first charge and discharge capacities exceeded the theoretical maximum of graphite and the average specific capacity achieved was comparable to that of highly refined spherical graphite.

Talga Managing Director Mark Thompson said, “These results are significant because charge capacity results matched, and for a period surpassed, those from batteries reliant on industry-standard spherical graphite anodes. The difference being that Talga’s sample came in a relatively raw natural state and did not require energy hungry milling and toxic refining steps. Aside from operational cost reductions without micronising and spheronising, any opportunity to avoid significant capital outlay on complicated spherical graphite plant and equipment is a huge bonus.

These results highlight the benefit of owning 100% of a very special resource that affords a truly new opportunity in the fast growing lithium-ion battery market.”

Talga solution

Vittangi predominantly consists of highly crystalline flake graphite that is naturally less than 15 microns, approximately the size of graphite commonly used in Li-ion battery anodes. This size flake graphite would ordinarily be difficult to separate using current standard methods, but as a result of Talga’s process technology (patent pending) the ultrafine graphite particles from Vittangi can be liberated and concentrated without any milling and with fewer steps than current commercially viable flow-sheets/mines. This process has already been scaled up from lab to bench, to pilot test scale and is currently being scaled up further at Talga’s pilot test facility in Germany. Coupling Vittangi ore with Talga’s patent-pending processing technique has the potential to produce a battery anode that requires 100% less milling energy compared to current industry practice. Particle size sought by industry is found in situ within the rock.

End users and next steps

No material processing equipment changes are required for next-stage battery testwork and follow-up work is underway to build on these initial promising results. Further identification of products for energy applications will be planned based on future results, research and commercial partner feedback.

Samples and/or discussions on sample supply agreements have commenced with Li-ion battery manufacturing leaders and material suppliers to the consumer electronic, transportation and energy storage system markets.

Maximising production output that reports to high-value specialised markets forms a large part of Talga’s strategic agenda.