As people use more portable power-consuming devices, the demand for batteries increases. Think cell phones, (video) cameras, , laptops, (remote controlled) toys and electric cars. Worldwide billions of batteries are thrown away each year and all of these contain toxic and corrosive materials, like cadmium, mercury, lead and lithium. The production, transportation and distribution of batteries uses up natural resources, contributing to an accelerating depletion of natural resources. Some of the worst environmental impacts of batteries come from mining and refining. Mines that extract metals like coral and nickel leave behind extremely toxic waste. They also require lots of energy to produce, resulting in more greenhouse gas emissions. Rechargeable batteries consume less nonrenewable natural resources than disposable batteries because fewer rechargeable batteries are needed to provide the same amount of energy. All batteries, disposable and rechargeable, become hazardous waste and pose threats to health and the environment if improperly disposed (for example, if they end up in landfills). Currently, around 90 % of lead-acid batteries are recycled.
Lithium, the metal that is found in rechargeable batteries, comes from two main sources: mines and brine water. Some 87% of the world’s lithium comes from brine water and of those brine water sources, briny lakes (known as salars) contain the highest concentration of lithium (1,000 to 3,000 parts per million). The salars with the highest lithium concentrations are located in Bolivia, Argentina, and Chile. Demand for lithium is increasing, since the rise of cell phones and electric cars. According to consultancy Cairn Energy Research Advisors, the lithium ion industry is expected to grow from 100 gigawatt hours (GWh) of annual production in 2017, to almost 800 GWhs in 2027. By 2040, batteries storing solar power for businesses and households will account for 57% of the world’s energy storage capacity.
To keep global warming below 1.5 degrees, 100 million electric vehicles should be added to our roads globally by 2030, stated the 2015 Paris Agreement. As the world tries to move from using fossil fuels to greener options, the environmental impact of finding all the lithium required to enable that transformation could become very problematic. Water is one of the problems. The process of making one ton of lithium requires approximately 500,000 gallons of water. The Lithium Triangle, which holds more than half of the worlds lithium supply and covers parts of Argentina, Bolivia and Chile, is already a dry region and using so much water has a big impact on local farmers. Another problem are the chemicals that could leak from the evaporation pools used to extract lithium into the water supply. These chemicals, including hydrochloric acid, are used in the processing of lithium into a form that can be sold, as well as those waste products that are filtered out of the brine at each stage.
But lithium is far from the only problem with rechargeable batteries. Two other key ingredients, cobalt and nickel, are more likely to have a huge environmental cost. Cobalt is found in vast quantities right across the Democratic Republic of Congo, and hardly anywhere else. The price has quadrupled in the last two years. Unlike most metals, which are not toxic when they’re pulled from the ground as metal ores, chronic exposure to cobalt-containing hard metal (dust or fume) can result in a serious lung disease called 'hard metal lung disease´. Inhalation of cobalt particles can cause respiratory sensitization, asthma, decreased pulmonary function and shortness of breath. Also dermal exposures to hard metal and cobalt salts can cause skin sensitization, which may result in eruptions of contact dermatitis (a red, itchy skin rash). In the DRC it is easy to find cobalt, so there’s a very strong motivation to dig it up and sell it, and a a result there’s a lot of motivation for unsafe and unethical behavior. The Congo is home to ‘artisanal mines’, where cobalt is extracted from the ground by hand, often using child labor (some of them as young as 4 years old), without protective equipment.
Companies that use a lot of lithium batteries, like Apple, Microsoft, Tesla and Samsung, acknowledged problems with the supply chain, but said they require suppliers to follow responsible sourcing guidelines. "As demand for rechargeable batteries grows, companies have a responsibility to prove that they are not profiting from the misery of miners working in terrible conditions in the DRC," Amnesty International said. "The energy solutions of the future must not be built on human rights abuses."
To reduce the impact of batteries on the environment, research is done to develop batteries that are smaller (higher density batteries, meaning that can store more energy in a smaller space), longer lasting, and have limited energy loss. Other considerations are recycling the materials and reusing the batteries for less intensive functions. For example, when the capacity of electric car batteries drops below 70-80% after about 10 years of use, they are no longer strong enough to power the car. But they can still be used for stationary storage in households, to balance power plants, or to electrify off-grid communities in rural areas. But repurposing and recycling is costly. Recycling lithium costs five times as much as extracting virgin material. This is why only 5% of lithium-ion batteries are recycled in Europe. What the real effect on the environment is, is a question that nobody really knows. “Assessing and reducing the environmental cost is a more complex issue than it initially appears,” says Christina Valimaki, an analyst at Elsevier. “For example, a less durable, yet more sustainable device could entail a larger carbon footprint once you factor in transportation and the extra packaging required.”
At this moment recycling is still too expensive, but with metal prices rising this picture could change. “At the end of the day it’s going to come down to whether the raw materials in the battery are worth more than the battery as grid storage,” analyst George Heppel at the Commodity research group CRU said. “I think there will be a better incentive to recycle the materials, and from there build a more efficient battery with new technology.”