Electric motors are significantly more efficient thaninternal combustion engines and thus, even accounting for typical power plant efficiencies and distribution losses,[3] less energy is required to operate an electric vehicle. Manufacturingbatteries for electric cars requires additional resources and energy, so they may have a larger environmental footprint in the production phase.[4][5] Electric vehicles also generate different impacts in their operation and maintenance. Electric vehicles are typically heavier and could produce moretire and road dust air pollution, but theirregenerative braking could reduce suchparticulate pollution from brakes.[6] Electric vehicles are mechanically simpler, which reduces the use and disposal ofengine oil.
As almost all electric cars haveregenerative braking, brake pads can be used less frequently than in non-electric cars, and may thus sometimes produce less particulate pollution than brakes in non-electric cars.[9][10] Also, some electric cars may have a combination ofdrum brakes and disc brakes, and drum brakes are known to cause less particulate emissions thandisc brakes.[11] Under theEuro 7 standard electric cars have a lower limit of brake particulates.[12][13][14]
Possible increasedtire pollution compared to fossil-fueled cars. This is sometimes caused by the fact that most electric cars have a heavy battery, which means the car's tires are subjected to more wear.[15][16] Devices to capture tyre particulates are being developed,[17][18] and under Euro 7 all new cars will have to meet the same tyre particulate limit.[19]
If electric cars are bigger than fossil fuel cars there may be moreroad dust pollution. However as of 2024 more research on road dust air pollution is needed.[2]
Plug-in hybrids and electric cars run offlithium-ion batteries andrare-earth elementelectric motors. As of 2016, ahybrid electric passenger car might use 5 kg (11 lb) of lithium carbonate equivalent, while one ofTesla's high performance electric cars could use as much as 80 kg (180 lb) of lithium carbonate equivalent.[20]
The demand for lithium used by the batteries and rare-earth elements (such as neodymium, boron, andcobalt[22]) used by the electric motors, is expected to grow significantly due to the future sales increase of plug-in electric vehicles. However in 2024The Economist wrote that "… within a decade or so most of the global demand for raw materials to build new batteries could be met byrecycling old ones.".[23]
In 2022 theIntergovernmental Panel on Climate Change said (with medium confidence) "Emerging national strategies on critical minerals and the requirements from major vehicle manufacturers are leading to new, more geographically diverse mines. The standardisation of battery modules and packaging within and across vehicle platforms, as well as increased focus on design for recyclability are important. Given the high degree of potential recyclability of lithium-ion batteries, a nearly closed-loop system in the future could mitigate concerns about critical mineral issues."[24]: 142
According to a 2020 study balancinglithium supply and demand for the rest of the century needs good recycling systems, vehicle-to-grid integration, and lower lithium intensity of transportation.[38]
Electric cars also have impacts arising from the manufacturing of the vehicle.[40][41] Electric cars can utilize two types of motors: permanent magnet motors (like the one found in theMercedes EQA), and induction motors (like the one found on theTesla Model 3). Induction motors do not use magnets, but permanent magnet motors do. The magnets found in permanent magnet motors used in electric vehicles containrare-earth metals to increase the power output of these motors.[42] The mining and processing of metals such aslithium,copper, andnickel can release toxic compounds into the surrounding area. Local populations may be exposed to toxic substances through air and groundwater contamination.[43]
Several reports have found thathybrid electric vehicles,plug-in hybrids and all-electric cars generate more carbon emissions during their production than current internal combustion engine vehicles but still have a lower overallcarbon footprint over thefull life cycle.[44] The initial higher carbon footprint is due mainly to battery production,[45] which may double the production carbon footprint as of 2023[update] but this varies a lot by country and is forecast to decrease rapidly during the decade.[46]
ICE vehicles typically produce more carbon emissions than EVs.[47][48] Some of the environmental impact is shifted to the site of thegeneration plants, depending on the method by which the electricity used to recharge the batteries is generated. This shift of environmental impact from the vehicle itself (in the case of internal combustion engine vehicles) to the source of electricity (in the case of electric vehicles) is referred to asthe long tailpipe of electric vehicles. This impact, however, is still less than that of traditional vehicles, as the large size of power plants allow them to pollute less per unit power than internal combustion engines, and electricity generation continues to become greener as renewables such as wind, solar and nuclear power become more widespread.[49]
Most of the lithium-ion battery production occurs inChina, where the bulk of energy used is supplied bycoal burning power plants. A study of hundreds of cars on sale in 2021 concluded that the life cycle GHG emissions of full electric cars are slightly less than hybrids and that both are less than gasoline and diesel fuelled cars.[50]
The operation of any car results innon-exhaust emissions such as brake dust, airborne road dust, and tire erosion, which contribute to particulate matter in the air.[52] Particulate matter is dangerous for respiratory health.[53][54] In the UK non-tailpipe particulate emissions from all types of vehicles (including electric vehicles) may be responsible for between 7,000 and 8,000 premature deaths a year.[52] Due toregenerative braking EVs produce less brake dust, but have more tire erosion due to their higher weight. This means that usually EVs have fewer non-exhaust emissions than combustion cars.[55] By 2050, cleaner air by the use of electric cars can save over 1163 lives annually and over $12.61 billion in health benefits in many major U.S. metropolitan cities such asLos Angeles andNew York City.[49]
Battery electric vehicles have lower maintenance costs compared to internal combustion vehicles since electronic systems break down much less often than the mechanical systems in conventional vehicles, and the fewer mechanical systems onboard last longer due to the better use of the electric engine. Electric cars do not require oil changes and other routine maintenance checks.[56][57]
Internal combustion engines are relatively inefficient at converting on-board fuel energy to propulsion as most of the energy is wasted as heat, and the rest while the engine is idling.Electric motors, on the other hand, are moreefficient at converting stored energy into driving a vehicle.Electric drive vehicles do not consume energy while at rest or coasting, and modern plug-in cars can capture and reuse as much as one fifth of the energy normally lost during braking through regenerative braking.[56][57]
BEVs are easily totaled because of battery damage,[58][59] and some have called for theright to repair.[60] Some EVs are made usinggigacasting to lower their cost, which complicates repairs.[61]
Overall whether an electric car uses more water than a fossil-fuelled car mainly depends on how the electricity is generated in the region that the car is used, for example in China in the 2010s an electric car used more.[62] Up to 150,000 liters of water are required to put out a single electric car fire. Fossil-fuelled car fires are typically extinguished using less than 4,000 liters.[63] However electric cars are much less likely to catch fire.[64]
Like internal combustion engine cars, most electric cars, as of 2023, containlead–acid batteries which are used to power the vehicle's auxiliary electrical systems.[65] In some countries lead acid batteries are not recycled safely.[66][67]
Current retirement criteria for lithium-ion batteries in electric vehicles cite 80% capacity for end-of-first-life, and 65% capacity for end-of-second-life.[68] The first-life defines the lifespan of the battery's intended use, while the second-life defines the lifespan of the battery's subsequent use-case. Lithium-ion batteries from cars can sometimes be re-used for a second-life in factories[69] or as stationary batteries.[70] Some electric vehicle manufacturers, such as Tesla, claim that a lithium-ion battery that no longer fulfills the requirements of its intended use can be serviced by them directly, thereby lengthening its first-life.[71] Reused electric vehicle batteries can potentially supply 60-100% of the grid-scale lithium-ion energy storage by 2030.[72] The carbon footprint of an electric vehicle lithium-ion battery can be reduced by up to 17% if reused rather than immediately retired.[68] After retirement,direct recycling processes allow reuse of cathode mixtures, which removes processing steps required for manufacturing them. When this is infeasible, individual materials can be obtained throughpyrometallurgy and hydrometallurgy. When lithium-ion batteries are recycled, if they are not handled properly, the harmful substances inside may pollute the environment.[73] These same processes can also endanger workers and damage their health.[74] Vehicle fires cause local pollution.[75]
Although there are several ways the electric motors can be recycled, as of 2024 about half of the magnetic material is lost: this is partly because very few manufacturers consider end-of-life in the design.[76]
^Ben Webster (29 July 2019)."Electric cars are a threat to clean air, claims Chris Boardman".The Times. Retrieved3 August 2019.The government's air quality expert group said this month that particles from tyres, brakes and road surfaces made up about two-thirds of all particulate matter from road transport and would continue to increase even as more cars were run on electric power.
^"Euro 7: Deal on new EU rules to reduce road transport emissions | News | European Parliament".www.europarl.europa.eu. 18 December 2023. Retrieved5 January 2024.The deal sets brake particles emissions limits (PM10) for cars and vans (3mg/km for pure electric vehicles; 7mg/km for most internal combustion engine (ICE), hybrid electric and fuel cell vehicles and 11mg/km for large ICE vans).
^Wu, Haohui; Gong, Yuan; Yu, Yajuan; Huang, Kai; Wang, Lei (1 December 2019). "Superior "green" electrode materials for secondary batteries: through the footprint family indicators to analyze their environmental friendliness".Environmental Science and Pollution Research.26 (36):36538–36557.Bibcode:2019ESPR...2636538W.doi:10.1007/s11356-019-06865-6.ISSN1614-7499.PMID31732947.S2CID208046071.
