Most of a battery’s emissions come from mining, refining and manufacturing. The most direct way to cut them is to need fewer and smaller batteries, then to build them with cleaner power and reuse or recycle them.
Key takeaways
- Batteries help cut emissions overall, but making them still produces greenhouse gases, mostly before the battery is ever used.
- Ars Technica reports that one way to make batteries cleaner is simply to make fewer of them.
- A battery sized for the job it actually does has a smaller footprint than one built for rare worst-case situations.
- The carbon intensity of the electricity used in factories and refineries has a large effect on how clean a finished battery is.
- Reuse and recycling can spread a battery’s manufacturing emissions over a longer life and reduce the need for newly mined materials.
What makes up a battery’s carbon footprint?
A rechargeable battery, such as the lithium-ion packs in electric cars, phones and home storage systems, builds up most of its emissions before it is first charged. The footprint starts with mining raw materials such as lithium, nickel, cobalt, manganese and graphite. Those materials then have to be refined into chemical forms pure enough for battery use, and refining often needs a lot of heat and electricity.
After that come the components. The cathode and anode materials are made, coated onto metal foils, dried, cut and assembled into cells, which are then built into modules and packs with casings, wiring and cooling systems. Several of these steps use a lot of energy, including drying the electrodes and keeping production areas at very low humidity.
Once a battery is in use, its emissions depend mostly on the electricity that charges it. At the end of its life, there are further emissions from collection, transport and either disposal or recycling. A battery’s total footprint is the sum of all these stages.
Why are battery emissions in the news now?
Batteries are central to plans for cutting emissions from transport and power. Electric vehicles replace engines that burn fuel, and grid batteries store renewable electricity for later use. As production grows, the emissions from making them become a bigger share of the total, and more people are asking how to reduce them.
Ars Technica has looked at this question. It reports that although batteries already have a relatively small carbon footprint, that footprint can be reduced further, and that one approach is to make fewer batteries in the first place. The full detail of the analysis behind that report is not summarised here, and readers should consult the original piece for its specific evidence.
The underlying argument is not new among engineers and environmental analysts. The cleanest battery is the one that never had to be built, and the next best is one built efficiently and used for as long as possible.
What background does a newcomer need?
The main tool for comparing products like these is life-cycle assessment. It tries to count all the emissions a product causes, from extracting raw materials to final disposal. For batteries, a life-cycle assessment usually reports emissions per unit of storage capacity, or, for vehicles, per distance travelled over the vehicle’s life.
Two ideas help in reading these assessments. The first is the “carbon payback”. An electric car starts life with higher manufacturing emissions than a comparable petrol or diesel car, largely because of its battery, and then makes up the gap through lower emissions in use. How fast it does that depends on how clean the local electricity is and how far the car is driven.
The second is that battery chemistry matters. Different cathode chemistries use different materials. Lithium iron phosphate cells, for example, do not use nickel or cobalt, which changes their supply chain and their environmental profile. Each chemistry involves trade-offs in energy density, cost, lifespan and material sourcing, so no single chemistry is best for every use.
Results vary between studies because they make different assumptions about factory locations, energy sources, battery lifespan and recycling rates. Comparing figures from different studies without checking those assumptions can be misleading.
Who is affected, and how?
Manufacturers and their suppliers are most directly affected. Where they put factories and refineries, and what electricity those sites use, shapes the footprint of every cell they make. Mining regions bear local environmental and social impacts that carbon figures alone do not show.
Car buyers are affected through product choices. A vehicle with a larger battery than its owner usually needs carries more manufacturing emissions, more weight and often a higher price. The same applies, on a smaller scale, to consumer electronics and to home storage systems that are oversized for the household’s demand.
Electricity grid operators and policymakers are affected because the emissions of both battery production and battery use depend on how clean the grid is. Recycling businesses and waste authorities are increasingly involved too, as the first large wave of electric vehicle batteries begins to reach the end of its life.
Where do informed people disagree?
One debate is about battery size in vehicles. Some argue that bigger batteries are needed to ease concerns about range and to encourage people to switch from combustion engines. Others say that better charging networks would let most drivers manage with smaller packs, cutting both emissions and the demand for materials.
A second debate is about reuse versus recycling. Batteries that are too worn for a vehicle can sometimes serve in less demanding stationary storage. Supporters say this makes the most of the manufacturing emissions already spent. Others point out that testing, refurbishing and integrating used packs is costly, and that sending them straight to recycling may sometimes be simpler and return materials to production sooner.
A third debate is about how much weight to give carbon compared with other impacts. Water use, land disturbance, pollution and working conditions in mining regions are not captured by a carbon figure. Choosing a chemistry or supplier on carbon alone could shift the burden somewhere else.
Finally, analysts disagree on assumptions. Expected battery lifespan, future grid mixes and recycling rates are all uncertain, and reasonable people choose different values.
What can readers and organisations actually do?
The practical steps follow the order of the lifecycle, starting with the decisions that avoid emissions altogether.
- Right-size the battery. For a vehicle, compare the battery capacity with your real regular journeys instead of occasional long trips that could be handled by charging along the way. For home storage, size the system to measured household use.
- Share and reduce demand. Car-sharing, public transport, cycling and electric bikes deliver mobility with far less battery capacity per journey. This is the most direct form of “making fewer batteries”.
- Extend battery life. Follow the manufacturer’s charging guidance, avoid leaving devices in extreme heat and choose products whose batteries can be replaced or repaired. A battery that lasts longer spreads its manufacturing emissions over more use.
- Charge on cleaner electricity. Where tariffs or smart chargers allow it, charge when renewable generation is high.
- Ask about sourcing. Buyers, especially businesses and public bodies, can ask suppliers about factory energy sources, chemistry and recycled content. Battery passports and disclosure rules are intended to make this easier in some markets.
- Return batteries properly. Use official collection points rather than household waste, so that materials can be recovered and fire risks avoided.
For manufacturers, the main levers are powering factories and refineries with low-carbon electricity, cutting energy use in steps such as electrode drying, choosing chemistries suited to each use and designing packs that are easier to repair, reuse and take apart.
What should we watch next?
Several developments will show whether battery footprints keep falling. One is where new cell factories and refineries are built, and whether they run on low-carbon power. Another is the growth of recycling capacity, and whether recovered materials become a meaningful share of supply.
Regulation is also worth following. Rules on carbon footprint declarations, minimum recycled content and battery passports are being developed in some jurisdictions, and how they are enforced will matter. Changes in chemistry, including the use of more abundant materials, could alter the picture as well, though how quickly and on what scale is not yet known.
Finally, watch how vehicle and device makers handle battery size. If smaller, longer-lasting batteries become a selling point, that will be a sign that the “make fewer” approach is taking hold.
Frequently asked questions
Do batteries produce more emissions than they save?
For most uses, no. Making a battery produces emissions, but an electric vehicle or grid battery charged with reasonably clean electricity usually makes up for those manufacturing emissions over its working life. How quickly that happens depends on the battery’s size, the local electricity mix and how heavily the battery is used. Oversized batteries that are used lightly take longer to pay back their initial carbon cost.
Which part of making a battery causes the most emissions?
Most emissions come before the battery is used: mining and refining raw materials, producing the cathode and anode materials, and assembling the cells. Refining and cell manufacturing are often especially energy-intensive, so the source of electricity and heat at those sites has a strong effect. The exact split between stages varies with chemistry, supplier and location, so no single answer applies to every battery.
Is a smaller electric car battery better for the environment?
Generally, a smaller battery means lower manufacturing emissions, less material and less weight, which can also improve efficiency. The key question is whether it meets your real needs. If a smaller pack covers your regular journeys and charging is available for longer trips, it is usually the lower-carbon choice. A battery that is too small for your use, and wears out early, could reduce that benefit.
What is a second-life battery?
A second-life battery is one that has lost too much capacity for its original job, often in an electric vehicle, but still works well enough for a less demanding role, such as stationary energy storage. Reusing it this way spreads its manufacturing emissions over more years of service. Before reuse, the battery needs testing and often refurbishing, which adds cost and complexity compared with sending it straight to recycling.
Does recycling batteries really reduce their carbon footprint?
Recycling can reduce the need for newly mined and refined materials, which are a major source of battery emissions. The size of the benefit depends on the recycling method, the energy it uses and how much material is recovered in usable form. Recycling also has its own emissions from collection, transport and processing. It works best alongside longer battery life and reuse, not as a replacement for them.
How can I make my phone or laptop battery last longer?
Avoid exposing the device to high heat, such as leaving it in a hot car, and try not to keep it fully charged or fully empty for long periods. Many devices offer optimised or limited charging settings for this purpose. When the battery does wear out, replacing it rather than the whole device keeps the rest of the product in use. Take dead batteries to an official collection point.
Sources and further reading
- Ars Technica: science coverage on the carbon footprint of batteries and the idea of making fewer of them.
- Peer-reviewed life-cycle assessment literature on lithium-ion battery production and use.
- International energy agencies’ reports on critical minerals and battery supply chains.
- Government and regulatory guidance on battery collection, recycling and carbon footprint disclosure.
Surfaced from the rss:arstechnica signal “battery manufacturing emissions”. AI-assisted draft, editorially reviewed.
