Carbon Footprint of Batteries: Manufacturing & CO2 Emissions By Type of Battery

It’s easy to recycle lead acid batteries at a mechanic’s shop or auto parts store. They’re one of the most recycled items in the world.

Lithium is a natural metal mined from the earth. These batteries are extremely high in energy density,¹ but they’re also very expensive to produce.

Reusing lithium and metals from recycled batteries can help significantly reduce the carbon footprint of lithium-ion batteries; however, they are difficult to recycle in some areas of the world. Lithium-ion batteries can safely be discharged up to 95%, which makes them more operationally efficient than lead-acid batteries.

Studies suggest the cradle-to-grave lifecycle of lead-acid batteries generates 50% more CO₂ emissions than the lifecycle of lithium-ion batteries.¹⁵

However, lithium mining practices are controversial, generating a devastating impact on the ecosystem, and safe disposal is also extremely energy intensive.

Producing Rechargeable Batteries (Lithium-Ion Batteries)

To calculate the carbon footprint of lithium-ion batteries, it’s important to understand the cradle-to-grave process for producing them.

While lithium-ion batteries power vehicles that produce far less carbon emissions than traditional gas-powered vehicles, the process of creating these batteries requires far more materials than producing a typical combustion engine.²

(Image: Spielvogel ¹⁸)

The lifecycle of a lithium-ion battery is outlined below:

1. Sourcing Raw Materials

Batteries are made up of lithium, cobalt, nickel, and dozens of other materials that are mined from underground clays or ores. Lithium can also come from brine, which is extracted from groundwater storage reservoirs.

Sourcing these materials requires significant fossil fuels, machines, vehicles, land, and water. It’s also time-consuming.

For example, extracting lithium from brine can take over a year. Most lithium comes from Australia, China, and Chile.⁹

The ecological damage from the mining process is immense.

2. Refining and Processing

This step involves preparing materials for battery production (ie: removing impurities from lithium carbonate).

In the case of lithium, brine must be kept under direct sunlight for an extended period of time so the water evaporates and lithium particles are filtered out.

3. Manufacturing

Creating the cathode, anode, electrolyte, and separator, constructing the battery (encapsulation and sealing), and testing for performance and safety are all part of the manufacturing process.

This requires high levels of energy, and in most parts of the world, the energy used is generated by burning coal or other fossil fuels.

4. Packaging and Distribution

Packaging the batteries and transporting them to manufacturers and retailers all over the world via air, sea, and rail.

Shipping emissions are being lowered through various maritime laws and other factors, but the packaging and distribution is still a significant generator of emissions.

5. Disposal and Recycling

The process of collecting batteries, breaking them down into pieces, recovering active metals, and reprocessing them for future use is also energy intensive.

Assessing the Carbon Footprint of Batteries (Electric Car Battery) Throughout the Product Life Cycle

Want to learn more about electric car batteries’ environmental impact?

Producing batteries, especially lithium-ion batteries that power electric vehicles, is a complex, labor-intensive process with a significant carbon footprint.

In each stage of the sourcing, processing, manufacturing, usage and recycling process carbon emissions are produced.

Sourcing Materials

Lithium-ion batteries are made up of an abundance of raw materials, many of which must be mined. Lithium salts are a primary ingredient, and they’re extracted from brine deposits and hard rock minerals.

Cobalt and nickel are also required and mining them in bulk is highly labor-intensive.

While demand for these natural materials is rapidly rising, it’s entirely possible for these resources to become depleted in the future. It’s expected that demand for lithium will increase from around 500,000 metric tons per year to up to 4 million metric tons by 2030.⁴

The process of sourcing materials needed for batteries includes:

1. Excavating: Removing large chunks of earth with heavy machinery and/or explosives. These machines and vehicles run on fossil fuels and explosives, which produce significant CO₂ emissions, both of which heavily contribute to global warming.
2. Extracting: Extracting lithium-rich ores from excavation sites. From manufacturing equipment to extracting the ore and the fossil fuels required to power the machines, extracting ore also generates a lot of greenhouse gasses.
3. Transporting: Extracted materials are transported to processing facilities all over the world either by truck, rail, sea, or air, which requires the burning of fossil fuels for energy.

So what’s the environmental impact? Lithium mining alone is estimated to produce 1.3 million tonnes of carbon annually and every tonne of mined lithium produces 15 tonnes of CO₂ emitted into the air.²

Cobalt mining is responsible for up to 1.5 million tonnes of CO₂ emissions every year.³ However, the environmental impact doesn’t stop with carbon emissions.

Mining results in land degradation, water pollution, and solid waste as well.

Processing and Preparation

After raw materials are sourced from the earth, they need to be processed and refined before they can be used in battery production. Some of the common steps involved in this stage of the life cycle include:

1. Ore Processing: Once extracted, the ore must be processed in order to produce the minerals needed to create the battery. This involves grinding the ore into tiny particles and applying chemical treatments to reach the required concentration.
2. Lithium Extraction: When pulling lithium from brine, salt-rich water from beneath the earth’s surface is pumped into a manufacturing facility where it goes through a series of evaporation procedures.
3. Refining: Once the lithium carbonate is mined, impurities must be removed. Pure lithium carbonate is essential for ensuring batteries are effective and efficient, so this step is very important. To achieve the desired results, the lithium carbonate is dissolved in water, filtered, and then receives a chemical treatment. Once this is complete, an evaporation and crystallization process is done to help the lithium carbonate achieve its purest form.

This process requires an enormous amount of fossil fuels, water, and machinery.

Carbon Footprint of Batteries: Manufacturing the Main Components of the Battery

So exactly how are EV batteries made? A rechargeable lithium-ion battery has four main parts: a cathode, anode, electrolyte, and separator.

These pieces work together to push electrons and ions that move in either direction through the circuit and electrolyte.¹⁶ Manufacturing each piece of a rechargeable battery is very labor-intensive and results in significant environmental impacts.

The entire process can take several weeks.

1. Cathode Manufacturing: Materials sourced for cathode construction must be carefully prepped to ensure batteries can achieve optimal performance.⁵ Lithium cobalt oxide, lithium manganese oxide, or lithium iron phosphate are the most common active materials used.
   These materials are mixed with graphite, which will allow for electron transfer within the cathode. This mixture is then applied to an aluminum foil current collector.
   After this step is complete, solvents are removed from the cathode during a drying process, which helps to ensure strong electrical conductivity.¹¹
2. Anode Manufacturing: An anode is an electrode in a battery that is important for the battery’s performance and efficiency. To create anodes, graphite powder is blended with binders and solvents, coated onto a copper foil substrate, and then dried.
   A layer of protective material is then applied, which prevents deterioration during charging.¹¹ Anode manufacturing can produce a lot of carbon emissions, sourcing and transporting graphite powder, solvents, copper foil, the machines used to create the anodes, and the energy needed to power the machines all generate greenhouse gasses. It all adds up.
3. Separator Manufacturing: The separator is a very thin, porous material that is stuck between the anode and cathode. Its purpose is to simply enable the movement of lithium ions and prevent short circuits.
   It’s usually made from polyethylene or polypropylene.¹¹ To create the separator, special machines are used to melt down these materials and form them into a film.
   The film is stretched, which creates microscopic channels that allow ions to pass through. The environmental impacts of separator manufacturing come from carbon emissions while sourcing polyethylene and ceramic materials, creating machines and equipment to melt it down and stretch it.
   Fossil fuels are required to power these machines.¹¹
4. Mixing Active Materials: For a battery to get its best performance, an even distribution of all the active materials must be evenly distributed throughout the battery. The active materials are mixed in a blender and then mixed again with solvents.
   The end product is a slurry that is used for electrode coating. These active materials include Lithium Cobalt Oxide (high energy density), Graphite (excellent conductivity), and Silicon (high capacity and high energy density).
5. Slurry Coating and Drying: The slurry composed of the active materials listed above is applied to the current collector. After it’s applied, the solvent must evaporate through a controlled drying process.
   After drying, the electrodes are compressed under high pressure to increase their density11.
6. Constructing the Actual Battery: Positive and negative electrodes are placed in alternating layers and the separator is placed between them to allow for ion transport. A conductive solution of electrolytes is placed within the battery.
   Finally, the battery is then placed in a protective capsule and sealed. This process involves metal cans, polymer pads that are used as insulation, and a protective epoxy coating.
7. Formation Cycling: To ensure maximum battery capacity, the batteries are fully charged and discharged multiple times to activate all the components of the battery. This process requires a significant amount of electricity.
8. Quality Assurance: Batteries are thoroughly tested for performance and safety, which also requires more rounds of charging and discharging, which also contributes to the carbon footprint of batteries.

So how much CO₂ is emitted during the manufacturing of lithium-ion batteries?

While publicly available data pertaining to carbon emissions from battery production are scarce, some studies have attempted to quantify the full impact of battery production using a life cycle assessment. This study suggests carbon emissions from battery production is 91.21 kg CO₂/kWh and the production of the cathode and battery assembly are the main drivers.⁶

Much of these carbon emissions are likely from energy sources required to create and operate machines.

The carbon footprint of lithium-ion battery production is likely the second most significant stage of the product life cycle (after sourcing the materials).

Packaging, Distribution, and Battery Usage

After batteries are manufactured and tested, they’re packaged and shipped to point-of-sale centers or electronics/EV manufacturers all over the world.

This results in significant greenhouse gas emissions and solid waste. This stage of the product life cycle includes:

1. Packaging: Rechargeable lithium-ion batteries are often wrapped up in packaging and shipped in boxes and crates.
2. Distribution: Batteries are shipped internationally by air and sea to manufacturers and retailers all over the world, which results in the burning of fossil fuels and increases the carbon footprint of batteries.
3. Consumption: Rechargeable batteries are removed from packaging and installed in electric vehicles, laptops, cellphones, and other electronic devices.

China produces the majority of lithium-ion batteries on the market today (79%) and the United States is second (6%). Shipping one large box across the US generates about 1.82 kg of CO₂ emissions.

Since most batteries used domestically are shipped from China by air or sea, the process generates significant greenhouse gas emissions. For example, a container ship generates 20 grams of CO₂ emissions per metric ton of cargo mile shipped, and shipping by air can be 20 to 30 times higher.

Any carbon emissions calculator will show significant carbon emissions from shipping internationally. Keep in mind that a single lithium-ion battery used in a TESLA Model 3 weighs about 1,000 pounds, so we’re talking about a lot of freight!

Battery Recycling

A lithium-ion battery manufactured for an electric vehicle usually lasts two to three years or 300 to 500 charge cycles.

However, even after a battery has reached the end of its life, it still contains cobalt, graphite, nickel, and lithium.

Therefore, when batteries are placed in the landfill, these materials are permanently lost. Not to mention chemicals from rechargeable batteries can cause significant damage to soil and water.

Recycling lithium-ion batteries is extremely important for the environment; however, like all activities, the recycling process still results in greenhouse gas emissions that must be considered when calculating the full carbon footprint of batteries.

1. Disposal/Collection: The expired battery must be transported to a retailer or recycling center.
2. Shredding: With a combination of machines and manual labor, recycled batteries are separated into pieces: copper, separators, plastics, steel canisters, and black mass. Black mass is a granular material made up of shredded cathodes and anodes.
3. Metal Recovery: Metals are recovered from the black mass through pyrometallurgy (a heat-based smelting process)⁷ or hydrometallurgy (a liquid-based leaching process).⁵
4. Re-Processing: Any materials recovered from the recycled battery must be processed before they can be used in new batteries.

While the process of recycling lithium car batteries has some negative environmental consequences, it’s important to remember that these impacts are minuscule in comparison to the process of creating new batteries.

Plus, CO₂ emissions from lithium-ion batteries made from recycled materials are 51.8% lower than batteries made from raw materials.^6,7 As a result, the benefits of recycling batteries far outweigh any negative environmental impact.

What Are Batteries Made Of?

Before you can truly appreciate the carbon footprint of lithium-ion batteries, you must understand what batteries are made of and how they work.

A lithium-ion battery consists of four main components:⁹

1. Cathode: Electrons enter an electric device through this negatively charged electrode. The cathode is coated in active material and determines the capacity and voltage of the battery.
2. Anode: Electrons leave an electric device through this positively charged electrode. The anode is also coated in active material and sends electrons through a wire.
3. Electrolyte: This piece enables the movement of only lithium ions between the cathode and anode.
4. Separator: The separator is a physical barrier situated between the cathode and anode.

These components work together to support the charge and discharge of ions. When a battery is powering an electronic device, lithium atoms in the anode (positive) are separated from their electrons and pushed through the micro-permeable separator via the electrolyte to the cathode (negative), which creates a flow of electrons that produces electrical energy.

During the charging cycle, the process happens in reverse, and lithium ions move back to the anode, where they’re stored and ready to repeat the discharge process.

Calculating the Carbon Footprint of Batteries (Lithium-Ion)

More than 79% of the world’s supply of lithium-ion batteries comes from China, and coal is the primary energy source used to power the sourcing, processing, and manufacturing of batteries. According to an article published by MIT, a single 80 kWh lithium-ion battery (the size needed to power a Tesla Model 3) would produce 3,120 kg (nearly 3 tons) of CO₂ emissions during the product life cycle.²

While this might seem significant, manufacturing lithium-ion batteries and using them to power electric vehicles is far better than traditional fuel alternatives.

Some studies claim replacing a single gas-powered vehicle with an electric vehicle would reduce 4.6 tons of CO₂ emissions on average every year.^8,10

However, others dispute that assertion. Toyota’s controversial 1:6:90 rule showed that it’s more efficient and eco-friendly to create 90 hybrid vehicles versus one electric.

In addition, the very process of mining the lithium is highly detrimental to the ecology of the area and the entire planet.

How Recycling Will Reduce the Carbon Footprint of Batteries?

Wondering how recycling will reduce the carbon footprint of batteries (or if it can)? Lithium-ion is a limited resource with some experts believing we could face a worldwide shortage as soon as 2025.

While there is no shortage yet, efforts to recycle existing materials from expired batteries are essential to extending the supply of materials.

(Image: muhammad faizuddin bin tukiran²⁰)

Recycling rechargeable batteries helps to battle concerns about material scarcity while promoting a secure and resilient supply chain. A 1 ton of battery-grade lithium can either come from 750 tons of brine, 250 tons of ore, or 28 tons of spent lithium-ion batteries.

Deriving these materials from spent batteries is by far the most energy-efficient. By further improving the efficiency of the recycling strategy,⁵ some experts believe we could reduce the carbon footprint of batteries by up to 91%.

This is a huge part of the U.S. plan to achieve net-zero emissions across the economy no later than 2050.⁵

However, recycling efficiency remains a challenge today. Lithium cathodes degrade over time, so they usually can’t be placed into new batteries and many battery manufacturers are concerned that using recycled battery parts could result in efficiency and quality issues.

However, some studies have shown batteries made from the process of recovering metals from “black mass”, as mentioned earlier, are just as effective as new batteries.¹²

Regardless, finding new and innovative ways to recycle batteries with greater efficiency will be key to reducing the carbon footprint of these products in the future.

The lifecycle of lithium-ion batteries (mining/processing materials, manufacturing batteries, shipping, and recycling) generates significant carbon emissions, but the question is: is it less than the carbon emissions generated by alternative energy sources such as fossil fuels? Is the carbon footprint of a gas-powered vehicle greater than a lithium-ion battery-powered vehicle?

The amount of carbon generated during the production of batteries may come as a surprise, but thankfully, government bodies and corporations across the globe are joining forces to improve battery production methods to lower carbon emissions.

Understanding the heavy carbon footprint of batteries is the first step to promoting more eco-friendly innovations that will reduce emissions, instead of keeping them where they are.

Frequently Asked Questions About Carbon Footprint of Batteries