1. Introduction
As the world moves toward decarbonization, renewable energy sources and electric vehicles are often heralded as key components of a more sustainable future. Central to these technologies are batteries, which store and deliver the energy needed to power homes, businesses, and cars. However, as we transition to these greener technologies, it is crucial to consider how environmentally friendly the batteries themselves are. Are they as green as they seem?
2. Environmental Impacts of Battery Production
The production of batteries, particularly those used in electric vehicles and renewable energy storage, involves significant environmental and social costs, casting something of a shadow over the otherwise promising prospects of a low-carbon future. At present, most all-electric vehicles and plug-in hybrids rely on lithium-ion batteries, and the key materials used in these — such as lithium, cobalt, nickel, and manganese — must be mined, processed, and fabricated into batteries, which is fraught with sustainability challenges.
a. Raw Material Extraction Has Major Environmental Consequences
Mining for lithium, cobalt, nickel, and manganese is resource-intensive and often environmentally damaging:
- Lithium: Extracting lithium requires substantial amounts of water, depleting water resources in already-arid regions. It is also estimated to generate between 5 and 15 metric tons of carbon dioxide emissions per metric ton of lithium depending on the extraction method.
- Cobalt: Over 70% of the world's cobalt supply comes from the Democratic Republic of Congo, where its extraction is associated with human rights abuses, child labor, unsafe working conditions, and considerable pollution of land and water sources. Cobalt production generated an estimated 1.6 million metric tons of carbon dioxide emissions in 2021, which is forecast to almost double to 3 million metric tons by 2030.
- Nickel: Mining of this element creates significant environmental problems, including deforestation and contamination of soil, water sources, and the ocean with heavy metals. Indonesia accounts for over one-third of the global supply, where legal and illegal nickel mining has had profound impacts on local ecosystems and communities. After the ore has been mined, the nickel must be recovered by smelting or high-pressure acid leaching, both of which are risky processes that create substantial pollution and problematic waste streams.
- Manganese: Manganese is another major mining pollutant responsible for soil and water contamination, especially in South Africa, the world's biggest producer. Manganese exposure can damage multiple organ systems and its extraction also often leads to deforestation and habitat destruction, impacting local ecosystems and biodiversity.
The mining, conversion, and refining of these elements is estimated to be responsible for 40% of the total climate impact of a typical battery. Focusing on lithium, which is crucial to the majority of modern batteries, much of the current supply is obtained from brine reservoirs located beneath salt flats in the so-called Lithium Triangle on the borders between Argentina, Bolivia, and Chile. This involves pumping the brine out into pits and allowing the water to slowly evaporate until the lithium concentration is high enough for refining. This is a thirsty process, with each metric ton of lithium estimated to need the evaporation of 1,900 metric tons of water, and it comes with the ever-present risk of leaks and spills.
In Australia, the world's biggest lithium producer, the element is instead extracted directly by mining hard rock to obtain lithium-containing ores such as spodumene, which then need to be crushed and processed to create usable lithium. This involves roasting at high temperatures followed by digestion with concentrated sulfuric acid to leach the lithium, consuming large amounts of energy and creating problematic waste streams.
b. Battery Manufacturing Is Energy-Intensive
After the raw materials have been extracted and refined, the process of turning them into batteries is also energy-intensive and has a significant carbon footprint. According to an International Monetary Fund report, a typical battery pack for an electric vehicle requires 8 kilograms of lithium, 14 kilograms of cobalt, and 35 kilograms of nickel, alongside other materials such as graphite for the anode, aluminum and plastic for the battery enclosure, and copper for the charging infrastructure.
Converting the raw materials into high-performance battery materials and components with the desired properties then assembling these into usable batteries is a complex, multistep process involving energy-intensive operations such as high-temperature calcination, solvent removal, and the maintenance of a dry room to protect the moisture-sensitive battery chemicals from degradation.
A study by the Swedish Environmental Research Institute found that the production of lithium-ion vehicle batteries emits between 61 and 146 kilograms of carbon dioxide equivalents for each kilowatt-hour of battery capacity, depending on the production method and means of electricity generation. Moreover, most lithium-ion batteries — approximately 75–80% of the global supply — are currently manufactured in China, where coal is still the primary energy source, resulting in substantial greenhouse gas emissions.
3. Environmental Impacts of Battery Use
Batteries are only as clean as the electricity used to charge them — charging batteries using electricity generated by burning fossil fuels simply leads to emissions elsewhere. In addition, the lifespan of batteries is a crucial factor determining their overall environmental impact. Longer-lasting and more efficient batteries reduce the frequency of replacement, thus lessening the environmental burdens associated with production and disposal.
a. Not All Electricity Is Created Equal
While batteries themselves do not produce direct emissions during use, their overall environmental footprint depends on how the electricity they store is generated. If the electricity comes from renewable sources like solar or wind, the environmental footprint of battery use is relatively low. However, if it originates from fossil fuels such as coal or natural gas, the associated emissions and environmental degradation offset some of the benefits of using batteries.
Thus, the true environmental friendliness of batteries hinges on a clean and sustainable energy grid, emphasizing the need for a comprehensive approach to decarbonization that includes both green energy production and efficient energy storage solutions. In this regard, batteries have another role to play here too, in that they are a crucial component of large-scale energy storage systems to help mitigate the intrinsic variability of renewable energy sources such as solar and wind. Thus, batteries have the potential to support the broader adoption of more sustainable methods of energy production. This is especially true for sodium-ion batteries, a more eco-friendly alternative that do not require lithium.
b. Batteries Do Not Last Forever
Electric vehicle batteries are currently expected to last for between 15 and 20 years (100,000–200,000 miles), with major manufacturers typically offering at least an eight-year warranty. However, as with all batteries, their efficiency degrades over time, especially when operated at extreme temperatures or subjected to heavy usage, resulting in decreased performance and storage capacity.
Battery manufacturers typically compensate for this inevitable capacity fading by oversizing their batteries to leave some "grace capacity" and minimize stress on the system components. While this extends battery life, it also means greater material use and higher vehicle weight (and thus higher energy usage).
These considerations are crucial for assessing the environmental impact of batteries because needing to replace batteries too often increases the environmental burden. Advances in battery management systems can help improve efficiency and extend battery life, but these technologies also add to the complexity and cost.
4. End-of-Life Considerations
Even the best batteries have a limited operational lifespan and must eventually be replaced. Ensuring responsible disposal and recycling is one of the most pressing challenges in the life cycle of batteries. Improper disposal can lead to severe ecological consequences, including soil and water contamination due to the leakage of toxic substances.
a. Batteries Should Be Disposed of Responsibly
When consumer batteries reach the end of their useful life, they often end up in landfills. Here, they can leak harmful chemicals such as heavy metals into the environment and increase the likelihood of landfill fires. This poses a threat not only to ecosystems but also to human health.
b. Recycling Processes Need To Be Improved
Recycling batteries can mitigate some of these environmental impacts. However, the recycling process is complex and requires additional energy and material inputs — the batteries must be collected, sorted, dismantled, shredded, separated, and processed to recover the valuable materials inside while properly dealing with hazardous waste streams. Moreover, recycling infrastructure is still lagging, and the diverse designs and chemistries used in modern batteries further complicate recycling efforts.
Despite these challenges, there have been promising advances in battery recycling technologies, such as advanced hydrometallurgical processes and direct recycling techniques. A number of companies have recently begun investing in collecting and recycling spent batteries. Battery recycling is also anticipated to become more economically attractive as raw materials become scarcer and battery waste becomes more plentiful. In the long term, the Volta Foundation predicts that recycling will play a key role in meeting market demand, especially when the first wave of electric vehicles reach their end of life toward 2030.
c. Greater Regulation and Designing for Recycling Will Be Critical
Governments around the world have begun to recognize the importance of battery recycling for ensuring a more sustainable future. For instance, the European Union is targeting a recycling efficiency of 70% by 2031 and has set goals for minimum levels of recycled materials to be used in newly manufactured batteries. Battery passports are also due to be introduced for larger batteries by 2027, with the ultimate aim of developing a closed-loop battery value chain in Europe. China and South Korea have already reportedly reached battery recycling rates of approximately 90%.
Encouraging responsible disposal and recycling practices is crucial — consumers, manufacturers, and policymakers must work together to create efficient recycling programs and regulations that minimize the environmental impact of spent batteries. Implementing circular economy principles, where batteries are designed for easier recycling and repurposing, would also be beneficial for further reducing their environmental footprint.
5. Conclusion
As we strive to build a sustainable future, it is essential to critically evaluate the environmental impact of the technologies we adopt. Batteries, while crucial for electric vehicles, renewable energy storage, and the consumer devices we all use, come with significant environmental costs that cannot be disregarded. From the extraction of raw materials to battery production, day-to-day use, and disposal, each stage of the battery life cycle has implications for our planet.
However, the future holds promise. Advances in battery technology, recycling processes, and sustainable extraction practices could help mitigate the environmental impacts of batteries. To ensure that batteries truly contribute to a sustainable future, we must support responsible production and disposal practices. Consumers and businesses can make a difference by choosing products from companies that prioritize sustainability and by participating in recycling programs. Meanwhile, manufacturers should continue to invest in research and development to create more efficient and environmentally friendly batteries, and policymakers must implement regulations that promote sustainable battery production and disposal, ensuring that environmental costs are minimized throughout the battery life cycle.
By working together, we can harness the power of batteries to support renewable energy and decarbonization while protecting our planet. The overriding goal should be to commit to making batteries as green as the technologies they power, paving the way for a truly sustainable future.
