Lithium batteries are a type of battery that uses lithium as a key part of its structure. These batteries are also called lithium-ion batteries and are often used in electric vehicles and electronic devices.
Lithium-ion batteries help support the use of energy from renewable sources like wind and solar power. However, the way lithium is traditionally extracted from the Earth can harm the environment.
Although lithium-ion batteries can be part of a solution for using energy more sustainably, replacing all devices powered by fossil fuels with lithium-based batteries might not be the best choice for the Earth. Lithium is a natural resource that can run out over time. Researchers at Volkswagen estimate there are about 14 million tons of lithium remaining, which is enough for 165 times the amount used in 2018.
Traditional methods of extracting lithium include mining from salt brines, lithium-rich clay, and ores. These methods can cause problems such as the loss of fresh water through evaporation, the release of harmful gases, chemical leaks, and other negative effects on the environment.
To reduce the harm caused by traditional methods, scientists have developed electrochemical extraction techniques. These methods are more efficient and cause fewer environmental problems. Electrochemical extraction uses electric fields to help dissolve metal ions, which means less heat and fewer chemicals are needed compared to traditional acid leaching. This method, especially when used with brine lakes, reduces the time required to extract lithium, lowering the risk of heavy metal pollution and the use of fresh water.
History
The first lithium battery was made by British chemist M. Stanley Whittingham in the early 1970s. It used titanium and lithium as the parts that carry electricity. This battery had problems because titanium was expensive and the chemical reaction made a bad smell. The modern lithium-ion battery, inspired by Whittingham's work and developed by Akira Yoshino, was first created in 1985.
Extraction
Lithium is taken from three main sources: salt brines, lithium-rich clay, and hard-rock deposits. Each method causes some environmental changes. Salt brine extraction is the most common, producing about 66% of the world’s lithium. A benefit of brine extraction is that it needs little machinery compared to other methods. Hard-rock deposits and lithium-rich clay both require mining with heavy equipment. All methods are still used because they recover similar amounts of lithium. Brine extraction recovers 97% of lithium, while hard-rock deposits recover 94%.
Brine extraction uses open-air evaporation to concentrate the brine over time. This process uses a lot of water, which is lost through evaporation. The water used is very salty and cannot be used for farming or drinking. After evaporation, the concentrated brine is sent to a production facility to make Li₂CO₃ and LiOH·H₂O. These facilities release harmful gases like sulfur dioxide into the air.
Most brine extraction sites are in South America, especially in Chile and Argentina, where about half of the world’s lithium reserves are in an area called the "lithium triangle." In Chile, the country’s two active mines, operated by Sociedad Química y Minera (SQM) and Albemarle, are located on the Salar de Atacama salt flat in the Atacama Desert. Tests showed the brine in these mines has about 350 grams of dissolved solids per liter. Studies found the water storage in Salar de Atacama decreased by -1.16 mm per year from 2010 to 2017. Some local communities accept money from mining companies and support their development projects, while others are ignored or refuse due to environmental concerns. In Tagong, a town in China, leaked chemicals like hydrochloric acid from nearby mines caused fish and animals to die in the Liqi River. Researchers believe this happened because of leaks from evaporation pools that remain unused for months or years.
Lithium can also be taken from hard-rock deposits, such as spodumene ores found in Australia, the world’s largest lithium producer. These deposits are less common than brine sources but have similar operating costs to brine extraction. As a result, hard-rock deposits are still used even though brine sources are more common and usually have less environmental impact.
Extracting lithium from lithium-rich clay involves mining the clay, which causes air pollution. Minerals like lepidolite, hectorite, and others in the clay contain lithium. After mining, the clay is processed using chemical reactions like acidification to extract lithium. This process can create harmful gases and chemicals that pollute the environment if not handled properly. Lithium-rich clay is the third major source of lithium but makes up less than 2% of global lithium production. Brine extraction accounts for 39%, and hard-rock ores account for 59%.
Because demand for lithium is growing quickly, new methods to extract lithium are needed to ensure a steady supply. A new method called electrochemical leaching has been developed to reduce environmental harm and energy use.
A major problem with traditional acid leaching is that it uses a lot of energy to reach high temperatures. Basic leaching methods require lower temperatures but need extra steps to remove impurities. These issues with chemical leaching have led to the search for better methods.
Electrochemical leaching uses an electric field to dissolve metal ions. It does not need the high temperatures or strong chemicals used in acid leaching, so it has less environmental harm. It can also use wind or solar energy for electricity. A study found this method achieved 92.2% efficiency.
Most lithium is taken from brine lakes (about 80%), as traditional mining methods are energy-intensive and have serious environmental effects. Extracting lithium from brine lakes using solar evaporation is a slow process, taking 1–2 years. This method uses a lot of freshwater, which can lead to heavy metal pollution and water shortages for farming.
Traditional brine extraction works best when the ratio of magnesium to lithium is low. New methods like electrochemical leaching are used for brine lakes with higher magnesium to lithium ratios. CDI is a new technology that uses charged electrodes to remove ions from salty water. This method uses little energy, is low-cost, and avoids chemical pollution. It removes ions by using an electric field to pull them toward carbon electrodes, separating them from the water.
Disposal
Some types of lithium-ion batteries, such as NMC, contain metals like nickel, manganese, and cobalt. These metals can be harmful and may pollute water and ecosystems if they leak from landfills. Fires in landfills or battery-recycling centers have also been linked to improper disposal of lithium-ion batteries. Because of these risks, some areas require lithium-ion batteries to be recycled. However, recycling rates remain low because recycling methods are still expensive and not fully developed. A study in Australia from 2014 found that about 98% of lithium-ion batteries were sent to landfills between 2012 and 2013.
Recycling
Lithium-ion batteries must be handled carefully from the time they are made until they are transported and recycled. Recycling is very important for reducing the harm lithium-ion batteries can cause to the environment. Recycling helps lower the amount of emissions and energy used because it reduces the need to mine and process new lithium.
The Environmental Protection Agency (EPA) has rules about recycling lithium batteries in the United States. Different methods are used for single-use and rechargeable batteries, so it is best to take all battery sizes to special recycling centers. This allows for a safer process to separate and reuse valuable metals from the batteries.
There are three main ways to recycle lithium-ion batteries: pyrometallurgical recovery, hydrometallurgical metal reclamation, and mechanical recycling. A study done in 2016 with recycling plants in Australia found that mechanical recycling recovered the most materials, getting 7 out of 10 possible materials from lithium-ion batteries on average. The same study showed that hydrometallurgy recovered 6 out of 10 materials on average, while pyrometallurgical processes recovered only 5 out of 10 materials on average.
Pyrometallurgical recovery involves processes like pyrolysis, incineration, roasting, and smelting. Most traditional industrial methods do not recover lithium effectively. These processes mainly focus on extracting other metals, such as cobalt, nickel, and copper. Recycling using this method is not very efficient, and it requires a lot of energy and resources. It also produces gas byproducts that need special treatment.
Hydrometallurgy uses chemical reactions to dissolve materials into a solution, which is later turned into solid materials for reuse. This method destroys organic materials like plastic during the process. However, it produces very pure metals, making it a useful recycling method. It is often used to recover copper and helps reduce harmful byproducts like sulfur dioxide that traditional smelting methods can create.
Direct or mechanical recycling involves breaking down old lithium-ion batteries to remove usable parts and materials that can be used in new batteries. This process includes shredding or crushing old batteries and then separating the materials. However, this method can cause cross-contamination, which may make some materials hard to recycle. While this is an option, it is usually more expensive than mining new materials. As demand for lithium-ion batteries grows, more efficient recycling programs are needed. Many companies are working to find the best recycling methods. A major challenge is that recycling is not often considered during battery design. One benefit of mechanical recycling is that it usually causes little or no pollution, unlike the other two methods, which can produce harmful chemicals and gases.
Application
Lithium-ion batteries are used in many ways because they are light, can be recharged, and are small. They are mostly used in electric vehicles and portable electronic devices, but are also being used more often in military and aerospace equipment.
The main industry that uses lithium-ion batteries is electric vehicles (EVs). Sales of electric vehicles have grown quickly in recent years. By 2019, over 90% of global car markets had incentives to encourage the purchase of EVs. As more people buy electric vehicles, there is less need for fossil fuels, which helps reduce harm to the environment.
Recent studies have looked at ways to reuse lithium-ion batteries from electric vehicles. In China, using recycled batteries from EVs to help manage energy demand during times of high electricity use has been shown to work well for power companies. However, spent lithium-ion batteries can harm the environment, and future supplies of battery parts for EVs may become limited. Because of this, rebuilding lithium-ion batteries should be considered.
A study using the EverBatt model in China found that rebuilding lithium-ion batteries is only cost-effective if the price of used batteries stays low. Recycling these batteries also helps the environment. Using remanufactured batteries reduces total greenhouse gas emissions by about 6.62%.
Environmental exposure
Lithium exposure has become a new problem in the 21st century because of the fast growth of lithium mining and its use in lithium-ion batteries for renewable energy and electric vehicles. Although lithium is important for the world’s shift to green energy, more evidence shows it might cause environmental and health risks if not handled properly.
A 2024 study called Lithium Levels in Umbilical Cord Blood from Two Cities in China found very high lithium levels in newborns. This suggests there are unknown, likely human-made sources of lithium exposure. The study shows that lithium pollution might not only affect people who work in mining or near mines but could also enter the human body through the environment in cities. This raises worries about long-term, low-level exposure during important times of development.
In 2021, large protests happened in Serbia against a lithium mine planned by the Rio Tinto company in Western Serbia. In 2024, another lithium mining project supported by the European Union caused more large-scale protests in Serbia.
A 2021 study explains that during the process of taking apart and recycling lithium batteries, harmful dust is released. Dust is a mix of tiny solid particles and liquid droplets of different sizes (from nanometers to micrometers) and chemical types, all floating in the air. Particles smaller than 10 or 2.5 micrometers (called PM10 and PM2.5) can harm human health, affect the climate, and reduce visibility in local and regional areas.