Lithium possesses unique chemical properties which make it irreplaceable in a wide range of important applications, including in rechargeable batteries for electric vehicles (EV).
Lithium is vital to the energy transition towards a low-carbon economy and demand is expected to increase by over 4x by 2030, reaching over 3m tonnes of lithium carbonate equivalent (LCE).
Most lithium is mined as rock minerals in Australia, while significant quantities are also produced from salars in Chile, Argentina and China. Lithium is produced from industrial mines by listed companies operating to high environmental, social and governance standards.
Although lithium is plentiful in the ground, significant investments in new mines and refineries are required for supply to meet demand in the future. Business uncertainty could jeopardize this investment.
As a battery raw material, lithium resources and supply chains are the subject of considerable political interest.
THE SCIENCE OF LITHIUM
Lithium is a soft, silver-grey metal that was first created during the Big Bang. It is an alkali metal, similar to sodium and potassium (but with a far smaller atomic size).
Pure lithium has a melting point of 181°C (357°F) and a boiling point of 1347°C (2457°F).
Lithium is used in rechargeable batteries because it is the lightest solid element (0.534 g/cm³) and its atom easily loses one of its electrons to gain positive charge.
Lithium reacts with water. It is never found as a pure metal in nature.
Lithium in rechargeable batteries Due to its very small atomic mass the lithium atom has a high charge and power-to-weight ratio, making it well suited to rechargeable batteries, especially for EVs where weight is at a premium, but also in stationary energy storage systems (ESS) and portable electronics. Potential substitutes, such as sodium-based batteries, are much larger and heavier compared with lithium batteries of the same power, making them unattractive
for most EV and portable applications (a lithium atom is just 30% of the weight of a sodium atom).
EVs are key to reducing manmade greenhouse gas (GHG) emissions. When using electricity from a renewable source an EV can reduce total life-cycle emissions by 89% compared to an equivalent petrol or diesel engine vehicle. Since 1991, when Sony produced the first commercial lithium-ion batteries, the proportion of lithium consumed in batteries has grown rapidly and is forecast to reach 90% of the lithium market by 2030.
Demand for lithium: strong growth forecast for many years The green transition will require considerable quantities of lithium. Many forecasters expect over 20% compound annual growth for the next decade, driven by demand from EVs.
From a 2022 market estimate of around 0.75 million tonnes of lithium carbonate equivalent (LCE), Albemarle, a market leader, predicts demand to reach 3.7 million tonnes LCE by 2030.
Lithium is a specialist chemical, not a standardised bulk commodity like copper or iron. The two commercial lithium compounds for
EVs are high purity ‘battery grade’ lithium carbonate (Li2CO3) and lithium hydroxide monohydrate (LiOH.H2O). The choice between them is usually determined by what type of lithium battery is going to be produced.
Global lithium deposits
Lithium is not rare; it is the 33rd most abundant element in the Earth’s crust with an estimated total mass of 98 million tonnes. Lithium is widely distributed in rocks, soils and natural waters. Lithium is always found as a compound in nature and therefore it must be purified before it can be used.
Lithium is mostly found in three deposit types: rock formations of granitic pegmatite, continental brines, and hydrothermally altered clays. Lithium production from rock and brine has been established for decades, while production from clay is at an advanced stage of development.
Two further types of lithium deposits are geothermal brines and deep oilfield brines.
The lithium industry has relatively few producers, with the largest companies owning both brine and rock mines, and integrated refineries. Smaller rock miners are usually non-integrated, and miners sell concentrate to downstream refineries for conversion to a lithium carbonate or hydroxide product, or for use directly within technical applications.
Developing a new lithium resource whether a spodumene mine or a brine resource usually takes between 5 and 10 years, while constructing a refinery can take 2-4 years. Both are significant investments which require a stable regulatory framework.
Both are significant investments which require a stable regulatory framework.
Production of lithium from rock minerals
There are over 250 lithium-bearing rock minerals, but only a few are mined. The most important mineral is spodumene, which contains about 8% lithium oxide theoretically. Other important minerals include lepidolite, petalite and zinnwaldite, while arguably the most photogenic is the gemstone pink tourmaline.
To extract lithium from spodumene the ore is crushed and sorted, roasted in a kiln at around 1150°C and then dissolved in sulphuric acid. The byproducts of spodumene refining include gypsum (used for soil improvement), lime and an alumino-silicate which can be added to concrete. Currently, the great majority of spodumene is mined in Australia and refined in China, although this is now changing as new mines and new refineries are being built around the world.
Production of lithium from salar brines
The largest known concentrations of lithium are in extremely salty continental brines found in the salt lakes and crusts (salars) of the high Andes mountains in Argentina, Bolivia and Chile in South America – the so called ‘lithium triangle’. Lithium is also produced from salars in the USA and China.
A typical salar is a high-elevation, arid, closed basin without drainage to the ocean, surrounded by volcanic deposits in an active tectonic region. This combination of factors means that as the volcanic deposits decay, the lithium and other salts are leached out and washed into the salar where they become trapped. In an arid salar the water evaporates, leaving behind the salts, which come to form a thick crust covering the basin. The crust is mostly common table salt (sodium chloride), but below the surface it is a supersaturated brine which can contain up to 35% dissolved salts, including lithium chloride.
In traditional lithium production brine is pumped out of the salt crust and stored in vast ponds, each larger than a football pitch
(see below). Here it remains for 12-18 months, during which time most of the water evaporates, making the dissolved salts even more concentrated. Later this fluid is refined to produce lithium carbonate.
Various direct lithium extraction (DLE) technologies are currently being industrialised, including some using membranes, electrochemical concentration and ion-exchange resins. The DLE process aims to allow the lithium salts to be removed from the host liquid without the need for
evaporation ponds and this technique could be applied to geothermal and oil-field brines too.
Key takeaways:
EVs are essential to reducing carbon emissions from transport. A typical EV requires about 7kg of lithium. A vast quantity of lithium and other critical battery raw materials will be needed to replace traditional vehicles with EVs.
Lithium is not rare but major investments are needed to increase mining and refinery production. The two key bottlenecks in lithium supply are mining and high-purity refining, each of which costs hundreds of millions of dollars to set up and run. For a country to attract investment in its lithium and battery industry, a stable business environment and appropriate regulation are essential.
There are no substitutes for lithium batteries without a significant loss of quality, reliability and functionality.
The future is circular. Recycling will become key to the future sustainability of transport, but currently, recycled lithium production is a relatively small industry. As more electric vehicles reach the end of their lives in the next decade recycling will play an increasingly important role.
The green transition is a global challenge which requires a global response. Cooperation, collaboration and coordination is crucial for success.
“This is the lithium century!”
