Robin Mentel explores the environmental impact of the mining of lithium, a material indispensable for the fight against climate change, and the extent to which we need to sacrifice the environment, in order to save the environment.
The fight against climate change confronts us with a range of uncomfortable compromises, that touch all aspects of our lives. A key strategy in reducing our emissions of greenhouse gases and preventing a global catastrophe is to make our mobility less reliant on fossil fuels, and change to electric vehicles (EV). Indeed, global demand for them has doubled in the past year. These new technologies bring with them an insatiable need for materials like cobalt and lithium. In particular, lithium, the lightest known metal, is a vital part of the batteries that power virtually every modern electronic device of the modern age, from laptops to sex toys to EVs. Demand for Lithium is currently exploding, especially due to the fact that it is needed for every new EV. However, this material, that drives the fight against climate change, has a concerning effect on its immediate environs, as it is mined to sometimes devastating effect.
Arguably the biggest advantage of your garden-variety combustion-engine car is that it doesn’t need very complex materials for its construction. You will only need some steel alloys for the engines and the tank, and a lot of copper for the electronics, but nothing too fancy. Its distinct negative impact on the environment comes into play only during its lifetime. EVs on the other hand, normally praised for their environmentally friendly nature, need a complex hotchpotch of elements and compounds for their engines and batteries, including elements like Graphite, Nickel, and Lithium. These materials of course don’t grow on trees, but have to be arduously mined. When we look at the countries that produce most of the worldwide lithium today, they are all countries with significant mining industries: Australia, which as of 2021 accounts for 55% of the global production, then Chile (26%), followed by China (14%).
How do we actually get the lithium from the ground into our batteries? Although it is a fairly common material on Earth, it always appears in low concentrations and is commercially accessible only from a small number of compounds. In general, it is currently mined either from hard rocks, which can be found largely in Australia and China, or from underground brines, which among others occur under the salt plains of the Atacama desert in Chile’s Andes. Here, Chile’s largest salt flat alone, the Salar de Atacama, holds about 40% of the world’s lithium. Lithium is a very light metal that can emerge at the surface in volcanic ash. Since it is easily soluble in water, rainwater quickly washes it out from the ash and transports it down the hills into the valley. Here, it settles with salt-rich water (as brine) below freshwater reservoirs due to its higher density. In order to get the coveted element from there, the brine is simply pumped out of the ground and then into large pools at the surface.
During the months of standing in the scorching sun of the driest desert on the planet, the water slowly evaporates, taking with it a number of unwanted compounds. The remaining brine is then treated to remove contaminants and washed and dried, to yield market-ready lithium carbonate. Although this does not need too much energy or heavy machinery, since the brine usually sits not too far below the surface, it comes as a significant strain on the environment.
The problems start with the fact that this method removes groundwater from the soil, and although the brine removed is of course not drinking water, it draws fresh water into the void, fresh water that then cannot be used for the animals, plants, and humans that live nearby. The indigenous peoples living along the edge of the plains have worried and complained about water shortages in recent years, though it is still unclear whether this is induced by climate change, by natural changes in the water environment of the desert, or indeed from the mining activities in the area.
One should also keep that in mind, when considering that it requires “Approximately 2.2 million litres of water to produce one tonne of lithium.”, as the water used hardly leaves the system, but simply evaporates into the air of the desert.
The other main method is extraction from rocks, which is not much gentler on the environment. The main problem is that the most common mineral that contains lithium, a crystal called spodumene, naturally only occurs in a very stable form, called alpha-spodumene. In order to make the crystal change its form, in order to get to the lithium, the mined rocks are grounded and roasted to some 1,000 degrees celsius.
In the new shape, called beta-spodumene, the lithium can react with sulfuric acid to form lithium sulfate, which can be processed into different lithium compounds. The mining and processing however is very energy demanding, much more so than the extraction of lithium from brine.
The problems associated with this method read like the typical issues associated with any traditional ore mining. For the extraction of the rocks, heavy machinery is used to tear through the terrain, requiring intense energy consumption, and the processing of the ores produces a number of toxic sludge and tailings, which (particularly in China) are rarely disposed of in an environmentally-friendly fashion. Leakages into the immediate environment of the mine are not uncommon, killing the plants and animals there. In the case of the Ganzizhou Rongda Lithium mine in Tibet for example, frequent spillages have killed numerous yaks and fish that drink from or live in the polluted water. The indigenous Tibetan people living there have little sway over the Chinese government to curtail the mining activity for their health’s sake.
The fight against climate change puts us in a difficult dilemma. The demand for the materials behind the technologies that enable a sustainable modern life, is pitched against the wellbeing of the environment and the peoples living near the deposits. Worse still, it is often these peoples that feel the brunt of the ongoing climate change already, and so are left in the truly unlucky situation of being harmed by both the problem and the solution. Given the soaring demand for lithium, and the fact that there is no real alternative in sight as of yet, the situation is probably not going to get much better any time soon.
Having said all that, there are silver linings on the horizon. One promising strategy is the recycling of lithium, especially for EVs whose large batteries are much less likely to be just thrown into the black bin together with normal batteries. Lithium recovery is not well researched yet, due to batteries being designed rather with the aims of longevity and low costs. Since there are hardly any regulations, most companies follow unique plans when designing them.
Thus, only a small percentage of lithium batteries are currently recycled. But the rising demand for lithium, and the associated rise in price, will make research into this technology more attractive in the coming years. This is especially amplified by the fact that while demand is soaring exponentially, supply is not - and so warrants a strategy to make batteries once we run out of lithium.
This timeline is especially worrying: We will likely run out of lithium by the end of this century. Another way out of this crisis is to use other materials rather than lithium in batteries. This is already the case with traditional car batteries that contain lead - but their large mass compared to the carried charge renders them unusable for most other mobile cases. But one can in principle replace lithium with other elements which chemically behave similarly to lithium, like potassium.
We will never in the future of mankind need to worry about running out of potassium, as it makes up a whole 2% (which is a lot, ask anyone with a mortgage!) of the entire earth’s crust, and makes our oceans salty.
Batteries using potassium are being researched and prototypes have already been built, but it will take a few more decades until the issues with this technology are figured out. For example, current iterations cannot last for longer than a few hundred charging cycles, while lithium batteries last for thousands of cycles. Nonetheless, potassium-based systems could be suitable for stationary energy storage, for example to store the energy generated by regenerative energies on windy, sunny days, for literal rainy days.