The strategic potential of brine

Together with nickel, manganese and cobalt salts, lithium hydroxide monohydrate (LHM) is used as cathode material in lithium-ion batteries. The growing demand for these batteries, including for electric vehicles and energy storage, is also driving demand for LHM, but due to a shortage of affordable lithium sources and production capacity, Europe is unable to meet that increasing demand. A significant scale-up of production is therefore essential.

Lithium salts occur naturally in rock, aquifers (underground water layers) and volcanic environments. They can be extracted from rock using sulphuric acid, producing lithium sulphate. In the traditional process, this is subsequently converted into LHM using soda and lime. The drawbacks of this process are that it generates many by-products, such as sodium sulphate and calcium carbonate, and that it requires large quantities of water.

‘Thanks to our knowledge of the thermodynamics of the system, we can steer and refine this process optimally’

Coert van Lare

German company Vulcan Energy, amongst others, is working on developing the extraction of lithium chloride from underground aquifers, where it is present as lithium-bearing brine. Through electrolysis, this brine can be converted into LHM. Without by-products, but this route is relatively energy-intensive compared to conventional chlor-alkali electrolysis of NaCl.

To address that problem, salt producer Nobian has developed a new process for the production of LHM from lithium chloride. In doing so, Nobian combines electrolysis of NaCl with the conversion of lithium chloride into LHM. In addition to consuming half the energy of direct electrolysis of lithium chloride, a major advantage is that existing plants and electrolysers can be used, reducing the investment required.

Thermodynamics

‘Nobian has not traditionally been a producer of raw materials for lithium batteries, but does have the ambition to grow in this market and become an important link in the European battery value chain,’ says Marco Waas, Chief Technology & Sustainability Officer at Nobian. ‘We have more than 100 years of experience in salt and electrochemistry, with existing production facilities in the Netherlands and Germany. That is why Nobian has everything it needs to produce these sustainable battery materials efficiently.’

‘Nobian has everything it needs to produce these raw materials efficiently’

Marco Waas

Lithium chloride has properties comparable to sodium chloride, which Nobian converts into caustic soda, hydrogen and chlorine through electrolysis. By analogy, lithium chloride can likewise be converted into lithium hydroxide in this way. Using a process diagram, Coert van Lare, Director Innovation Programme Renewable & Circular, explains the new setup. ‘The process combines chlor-alkali electrolysis with crystallisation of LHM. The basis of the process is the existing chlor-alkali electrolysis of NaCl in water, which produces chlorine, NaOH and hydrogen. NaOH is mixed with lithium chloride, after which LHM is crystallised by cooling. The NaCl is then also crystallised by evaporating water, after which it enters the electrolysis plant to produce NaOH once more. An essential part of the process is when and where we blend in the caustic soda and lithium chloride. By analysing the phase diagrams, we have identified the most favourable point. Thanks to our knowledge of the thermodynamics of the system, we can steer and refine this process optimally.’

Hundreds of kilograms

Nobian recently concluded an agreement with Veolia to further scale up the process using a demonstration plant to hundreds of kilograms of LHM per year. Veolia has extensive experience in building installations for the production of various lithium compounds and possesses knowledge of LHM behaviour. Veolia has already tested Nobian’s new process at litre scale in the pilot installation in Plainfield, Illinois, in the United States.

The two companies are now working on further optimisation of the process conditions. A key challenge is the separation of the salts, Van Lare explains. ‘The composition of the lithium-bearing brine depends on the source. The quality of the brine influences the process. We are investigating the effect of the percentages and types of impurities on the electrolysis and crystallisation process. To be suitable for use as a battery raw material, LHM must be exceptionally pure.’

Nobian wishes to contribute to the establishment of a European value chain for lithium, with an eye on the growing European and global demand for battery materials. Waas: ‘Building a battery value chain is strategically important for Europe. Demand for lithium batteries is rising, and in order not to be dependent on foreign countries for critical raw materials, it is important to scale up their production within Europe.’ This requires investment across the entire chain. The company is in talks with suppliers, both within Europe and beyond, for the supply of lithium chloride.

In addition, the search is ongoing for investors and potential licensees to further scale up production capacity. Nobian expects to be able to realise a commercial installation for the production of LHM by the end of this decade. Waas: ‘That is quite swift when you consider that we began researching the possibility of producing battery materials five to six years ago and have only been working on LHM production for around three years.’