Leveraging lithium

In the fifth instalment of the Australian Mining Review’s critical minerals series, we speak with Australia’s national science agency, CSIRO Futures mineral resources lead Max Temminghoff and CSIRO critical minerals lead with the Australian Critical Minerals Research and Development Hub Chris Vernon for a deep dive into emerging mid-stream processing pathways for lithium as highlighted in the agency’s From Minerals to Materials: An Assessment of Australia’s Critical Minerals Mid-Stream Processing Capabilities report.

Lithium-ion batteries (LIBs) are expected to drive a surge in demand for critical battery materials lithium, cobalt and graphite. These essential minerals present significant concentration and sustainability concerns across their supply chains, meaning research, development and demonstration (RD&D) activity will need a boost, both domestically and globally, to ensure the robust and ethical supply required for the energy transition. 

The IEA estimates that lithium demand will see eightfold growth by 2040 due to its crucial role in batteries. Despite this, lithium is experiencing a downturn in prices, potentially discouraging activity and investment in the sector. Further development of low-cost processing pathways will be needed to meet anticipated future demand. 

As a world-leader in lithium, Australia has a pivotal role to play. 

Mr Temminghoff says Australia holds nearly 18% of the world’s economic lithium reserves, primarily in hard rock spodumene deposits.  

“In terms of active global mine production capacity, Australia accounts for nearly half,” he said. 

“Enhancing midstream processing capabilities in lithium could significantly increase Australia’s value-add opportunities, enabling the export of higher-value products such as lithium metal, cathode active material and electrolytes.  

“A commercial capability would also solidify Australia’s position as a key player in the shift towards diversified global supply chains.” 

Lithium prices have taken a tumble as supply outpaces demand, driving a drop from the 2022 price of around $128,000/t for lithium carbonate, to today’s value of about $15,500/t. While the rush to electrical vehicles (EVs) is playing out a bit differently than initially expected — with China overwhelmingly adopting the technology as the Western world lags. However, as adoption increases gradually, lithium prices are expected to recover alongside it. 

The nimble and responsive nature of the Australian lithium industry, thanks to our wealth of hard rock deposits, will enable us to keep the momentum going despite the current low-price environment. 

Dr Vernon says that if Australia improves its midstream processing capabilities, it can become a price maker rather than a price taker. 

“At the moment the spodumene market is quite boom bust,” he said. 

“The price goes through the roof, so more producers start producing, then there’s a surplus and the price crashes, so mines go into mothballs. 

“If you’re a bit more downstream, making battery grade lithium hydroxide for example, you command the price because your product is going directly into battery manufacturing and chemicals manufacturing business, rather than just supplying the raw material.  

“You get a little bit more control of what price you can get and the market your product ends up in. 

“You also get a broader range of other businesses that will buy from you, so that you are not committed to selling only to an overseas lithium refinery — now you’re in a business where you can sell direct to battery manufacturers.  

“This broadens the scope of the customers you might be dealing with.” 

Production of lithium compounds

Globally, the two primary sources of lithium are hard rock ores and brines, each requiring a different extraction pathway. All of Australia’s lithium production is from hard rock ores, the vast majority being spodumene. In the future, this may also include lepidolite and petalite. 

Mining hard rock ores involves a beneficiation step, where lithium ores are sorted to eliminate other materials and obtain a lithium concentrate. Then, lithium is extracted from the lithium concentrate through a mature multi-step process.  

First, the ore concentrate is calcined to transform it into a more reactive state. The calcined ore can then be subjected to roasting, leaching and purification processes to produce battery grade lithium compounds. 

Mr Temminghoff comments on Australia’s capabilities in the production of lithium compounds. 

“Australia has world leading RD&D capabilities in both the calcination of spodumene and the purification of lithium compounds, providing a pathway for Australia to partially reduce its reliance on overseas technology providers,” he said. 

However, recoveries and waste generation in the production of lithium compounds could be improved. The challenge in these areas is primarily due to the low proportion of lithium in natural ores (about 4-8% lithium oxide) compared to other materials like aluminium and silicon. 

“People sometimes say that 30%, sometimes 50%, of the lithium that’s actually in the rock isn’t recovered in the concentration process,” Dr Vernon said. 

“For some reason, some of the spodumene doesn’t float in the flotation step and it reports with the waste.  

“A significant proportion of the lithium mined doesn’t end up getting processed, it goes out with the waste rock. 

“At a refinery, there’s a significant sodium sulfate waste stream.  

“Now, is it a waste? Is it a byproduct? It depends if you’ve got a buyer for it.  

“Sodium sulfate is used as an industrial chemical, and most notably as a filler in detergents.  

“So, if you have a deal where you can sell that sodium sulfate to someone else who’s going to use it in their process, that’s fantastic.  

“If not, you’ve got a problem in disposing of that material when you’re finished.”  

Calcination

Naturally occurring spodumene, ?-spodumene, is resistant to conventional extraction processes, meaning an initial thermal process is required to convert it into a more reactive form, ?-spodumene. 

Calcination is necessary to extract lithium from these hard-rock ores, since it makes the ores more amenable to leaching. It is a mature process but there is significant opportunity for innovation. 

In calcination, mineral ores or compounds are subjected to high temperature to enable extraction or removal of impurities. This typically takes place in a rotary kiln where feedstock is heated and mixed. This is an energy-intensive process powered by natural gas.  

According to CSIRO, the high energy intensity of the process remains a key challenge, warranting innovation.  

RD&D focus areas

Calcination

• Advancing calciner design to improve efficiency. 

• Integration of renewable energy. 

• Developing cost- and energy-efficient pathways combining mechanical activation and microwave irradiation. 

Roasting

In the roasting process, ore is reacted with a chemical reagent in the presence of oxygen in a high temperature environment. 

According to CSIRO, sulphuric acid roasting is already commercially deployed in Australia due to its high maturity level, simpler operational requirements and lower costs relative to other pathways. 

Improvements to existing technology and cross-cutting research, supported by domestic and international collaboration offer opportunities for RD&D. 

RD&D focus areas

General

• Developing and scaling up alternative, energy efficient roasting mechanisms such as microwave-assisted heating to reduce energy and reagent consumption. 

Sulphuric acid roasting

• Developing treatment processes for residues to optimise lithium recovery and energy efficiency 

Salt roasting

• Piloting and scaling up methods for spodumene ores to improve extraction and energy efficiency 

• Developing solutions to minimise and treat any waste residues. 

• Designing and optimisation at commercial scale, including improving control of reaction conditions 

Chlorination roasting 

• Development of materials and plant equipment to protect against the corrosive nature of chlorinating agents. 

• Implementing closed-loop system design and using absorbents to capture chlorine gas byproduct. 

Leaching

Conventionally, leaching is performed after calcination and roasting to form solid or soluble lithium compounds. However, new approaches are being developed to leach ores without calcination or roasting, by employing acids and alkali solutions. 

With the world-leading IP activity and active commercial development, Australia is well placed to undertake RD&D to scale up novel leaching methods without significant technology support from overseas partners, according to CSIRO. Supporting domestic RD&D in this space can help position Australia as a sustainable and competitive lithium compound producer and a global technology innovator.  

RD&D focus areas

Acid and alkaline leaching

• Developing closed loop systems for reagent recovery and regeneration. 

• Developing and scaling up technologies to minimise and treat any waste residues. 

Bioleaching 

• Increasing the efficiency and flexibility of bioleaching which includes designing processes to target low-grade ores and developing microorganisms with improved tolerance and effectiveness. 

• Designing large-scale bioreactors with automated and streamlined operations to improve efficiency and reduce cost. 

Production of lithium metal

High purity lithium metal is needed for next generation lithium-metal batteries, where it is used as an anode material.  

Lithium metal is highly reactive and must be produced and stored in a vacuum or inert environment to prevent the lithium metal from reacting with air or water. 

According to CSIRO, the most commercially mature method for producing lithium metal is by electrolysing the lithium chloride component of a molten salt mixture at high temperatures. This method is mature and well understood, but due to the use of highly pure and expensive lithium chloride as feedstock, represents cost and efficiency challenges. 

To reduce chlorine gas emissions and reduce costs, variations of the electrolysis process are being developed that use more accessible lithium compounds such as lithium hydroxide and carbonate. 

RD&D focus areas

Electrolysis

• Designing and scaling up non-chloride, low temperature processes. 

Thermochemical reduction 

• Investigating sustainable heat sources and heating techniques to achieve the high temperature requirement. 

Supporting research domains 

• Applying advanced modelling to enhance the understanding of reduction chemistry and the dynamics of thermochemical reduction. 

Synthesis of cathode active materials (CAM)

Cathode active materials (CAM) are necessary in the production of lithium-ion batteries. According to the IEA, global cathode demand in 2030 for EV batteries alone could increase sixfold compared to 2021. The surge in demand, paired with the economics of the cathode being the highest cost proportion among battery components in relation to raw materials and processing makes this strategically important to Australia. 

CAM synthesis brings together the battery-grade compounds from multiple supply chains into a single, value-adding step. According to CSIRO, the process is the bridge between upstream extraction and downstream battery component and cell manufacture, making it strategically important to Australia.

Due to the technology’s sensitivity, and the changes in size, shape and structure based on production method, advancement in this area is directly linked to improvements in battery performance. RD&D can deliver technical improvements in manufacturing costs, sustainability and material properties. 

CAM synthesis RD&D focus areas

Co-precipitation

• Designing and optimising the co-precipitation process at scale, which requires precise control of reaction parameters. 

• Reagent recovery and waste-water recovery and treatment 

Sol-gel

• Designing and optimising the sol-gel process at scale, to address the significant volume of reagents required and ensure precise control of reaction parameters 

Solid-state

• Lowering the time required for synthesis and increasing CAM particle homogeneity. Greater control over particle characteristics could be enabled by improved mill designs and techniques that produce ultra-fine CAM competitively at commercial scale. 

• Developing and demonstrating single-step, non-fossil duel thermal treatment methods such as plasma- and microwave-assisted synthesis. 

 Synthesis of electrolyte materials

Current generation lithium-ion batteries use liquid electrolytes — lithium electrolyte salt and additives dissolved in a mixture of solvents. Advantages of liquid electrolytes include high conductivity and good contact with the electrodes. However, its application is limited by safety concerns regarding the flammability of current solvents (organic carbonates) and battery longevity limited by low cycling efficiency. 

Lithium hexafluorophosphate currently dominates as the most prevalent electrolyte salts in use. The synthesis of it is complex and involves hazardous and expensive chemicals. Lithium hexafluorophosphate is also at high risk of degrading and releasing toxic hydrogen fluoride if exposed to moisture, requiring strict storage conditions after synthesis, particularly during transport. 

Increased RD&D in interested in alternative lithium electrolyte salts with improved conductivity and stability. Alternative salts include lithium bis(trifluoromethanesulfonyl)imide and lithium bis(fluorosulfonyl)imide, which are more stable and less likely to release toxic hydrogen fluoride, improving safety and longevity. However, because these salts are corrosive, battery longevity could be a concern. 

Liquid electrolytes RD&D focus areas

Liquid electrolytes

• Developing and testing alternatives to organic carbonate solvents to improve safety. 

• Investigating different salt combinations and ratios to optimise cycling efficiency and battery longevity 

Lithium electrolyte salts

• Developing reduced fluorine materials and chlorine-free synthesis pathways. 

• Developing alternative electrolyte salts with reduced fluorine content. 

• Optimising Lithium hexafluorophosphate synthesis at scale. 

 Solid electrolytes have been developed to eliminate the need for solvents, significantly improving battery safety. There are three main types: solid polymer electrolytes (SPEs), inorganic solid electrolytes (ISEs), and composite solid electrolytes (CSEs). 

Solid electrolytes RD&D focus areas

SPEs

• Developing and scaling up additive manufacturing (i.e., 3D printing) techniques to enhance compatibility between the SPE and electrodes, reducing cost and material wastage. 

• Developing different polymer combinations to improve conductivity. 

• Advancing SPEs’ physical and mechanical properties and introducing additional structural components to improve battery safety and durability. 

• Investigating the use of biopolymer materials 

 ISEs

• Advancing manufacturing techniques, including additive manufacturing, to process and handle brittle and unstable inorganic materials and reduce costs and wastage. 

• Developing coating or structural engineering solutions to facilitate the interaction between electrodes and ISEs. 

CSEs

• Optimising the chemical and structural design of CSEs. 

• Advancing the manufacturing techniques to reduce energy and cost and improve product quality and efficiency. 

• Investigating low-cost fillers and biopolymers. 

• Advancing the understanding of ion transport mechanisms and the behaviour of various phases comprises a CSE within batteries