Electric vehicles are becoming more popular, with governments even encouraging their use through legislation. Here we look at what makes these vehicles different from fuel-based cars, and the battery technologies that drive them.
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Electric Vehicle Market Today
In an electric vehicle or hybrid electric vehicle, the electric motors are powered by a rechargeable battery. Their use is becoming increasingly adopted by many countries.
An executive order signed by US President Joe Biden mandates that by 2030, electric vehicles must account for 50% of all new car sales. A similar requirement that calls for electric cars to account for 40% of all sales is in place in China, the largest EV market in the world. Additionally, the European Union wants at least 30 million zero-emission vehicles on its highways by that time.
Currently, there are an estimated 5 million electric cars in circulation in China, making it the nation with the most electric cars. With about 1.77 million cars, the US comes second, followed by Germany with 570,000 cars.
What are the Main Components of Electric Vehicle Batteries?
The most important component of electric vehicle technology is the battery. Modern electric vehicles mainly have lithium-ion and lithium polymer batteries due to the relatively higher energy density compared to weight.
The major materials required in lithium-ion batteries are the chemical components lithium, manganese, cobalt, graphite, steel, and nickel. These components all have different functions in the typical electric vehicle battery that contribute to improved performance.
Lithium-ion batteries internally move lithium ions from one layer, known as the anode, to another, known as the cathode, to generate power. Lithium-ion batters are more convenient to use in electric vehicles because compared to lead-acid or nickel-metal hydride batteries, lithium-ion batteries offer higher energy densities, making it possible to reduce battery size while maintaining storage capacity.
Safety is the main reason manganese is used in lithium-ion batteries. Because of its increased energy density properties and reputation for stability, manganese is known to increase capacity and improve driving range. Additionally, manganese reduces the combustibility of electric vehicle batteries, which is problematic with lithium-ion batteries that contain cobalt.
Cobalt helps extend the life of batteries, which manufacturers typically guarantee for eight to ten years, and it also guarantees that cathodes do not quickly overheat or catch fire.
Graphite plays a critical role in the anode that stores lithium ions. Most commercially available lithium-ion batteries employ graphite due to its good cycle stability and energy density.
Steel provides the best balance of strength, mass reduction, performance, cost, and environmental impact. Steel is the preferred material for today's automobiles and will continue to be the preferred material for vehicles in the future.
Electric vehicle batteries contain nickel, jet engine turbines employ nickel alloys, and passenger trains and subways use stainless steel that contains nickel. Materials containing nickel provide improved corrosion resistance as well as dependable and effective electrical and spark systems.
What are the Different Types of Electric Vehicle Batteries Available?
The most common chemistries for electric vehicle batteries are Lithium-ion (Li-ion), Nickel Manganese cobalt (NMC), Nickel Metal Hydride (Ni-MH), Lithium Sulphur (Li-S), and Lead-Acid. Nickel-metal hydride batteries are often used for hybrid cars instead of Lithium-ion.
Aside from the different types of chemistries, there are different formats for electric car batteries: cylindrical, prismatic, and pouch cell. Cylindrical cells are the cheapest to manufacture, prismatic cells can store more energy, deliver more power, and have better heat management, while pouch cells use space more efficiently and deliver the most power.
There are growing concerns about the continuous supply of these raw materials for the manufacture of electric vehicle batteries. When considering the resources available on the planet and our ability to cost-effectively extract them with the available technology, we can estimate whether supply can meet demand in the future.
According to analysts, there could be a potential shortage in the global mining capacity to mine the number of raw materials required to meet the projected demand for electric vehicles.
For example, there are projections that the proportion of cobalt could decrease significantly to about 60g/kg dry cell weight from 200g/kg. For this reason, Tesla is attempting to produce cars that are about $10,000 cheaper by employing cobalt-free batteries. For lithium, there are currently no indications of a possible shortage soon, but environmental problems associated with poor disposal of lithium batteries continue to persist.
What is the Future of Electric Vehicle Batteries?
Electric vehicles seem to have come to stay, as their demand is continuously increasing. Research and development at various companies is significantly improving the performance of electric vehicle batteries by reducing the cost of production, increasing their power, and improving their range.
For example, solid-state and liquid-air battery technologies are being researched as alternatives to Li-ion batteries. Solid-state batteries use solid ceramic rather than electrolyte ions to carry current, and they are expected to charge faster, contain more power, and cost less to produce. Liquid air battery technologies have higher energy density and could have cheaper and longer-lasting components. In the next decade, we might see them in circulation.
Other approaches such as making recyclable battery cells could help significantly to reduce the pressures on mines.
More from AZoM: How are Graphene Batteries Made?
References and Further Reading
Backhaus, R., 2021. Battery Raw Materials - Where from and Where to? MTZ Worldw 82, 8–13. https://doi.org/10.1007/s38313-021-0712-5
Castelvecchi, D., 2021. Electric cars and batteries: how will the world produce enough? Nature 596, 336–339. https://doi.org/10.1038/d41586-021-02222-1
Corp, M.X.E., 2022. Increasing Lithium-Ion Battery Demand Manganese Industry Expert Report [WWW Document]. GlobeNewswire News Room. URL https://www.globenewswire.com/en/news-release/2022/03/08/2399455/0/en/Increasing-Lithium-Ion-Battery-Demand-Manganese-Industry-Expert-Report.html
Desai, P., 2022. Explainer: Costs of nickel and cobalt used in electric vehicle batteries. Reuters. URL https://www.reuters.com/business/autos-transportation/costs-nickel-cobalt-used-electric-vehicle-batteries-2022-02-03/
House, T.W., 2021. FACT SHEET: President Biden Announces Steps to Drive American Leadership Forward on Clean Cars and Trucks [WWW Document]. The White House. URL https://www.whitehouse.gov/briefing-room/statements-releases/2021/08/05/fact-sheet-president-biden-announces-steps-to-drive-american-leadership-forward-on-clean-cars-and-trucks/
Laserax, 2022. Electric Vehicle Battery Cells Explained [WWW Document]. Laserax. URL http://www.laserax.com/blog/ev-battery-cell-types
Miao, B., Shen, L., Liu, X., Zeng, W., Wu, X., 2020. Bioinformatics and Transcriptional Study of the Nramp Gene in the Extreme Acidophile Acidithiobacillus ferrooxidans Strain DC. Minerals 10, 544. https://doi.org/10.3390/min10060544
Nickel role in transport | Nickel Institute [WWW Document], 2022. URL https://nickelinstitute.org/en/about-nickel-and-its-applications/nickel-and-transport/
pvEurope, 2021. Electric vehicles: - Global EV count climbs to 10.9 million - pv Europe [WWW Document]. URL https://www.pveurope.eu/e-mobility/electric-vehicles-global-ev-count-climbs-109-million
Sanguesa, J.A., Torres-Sanz, V., Garrido, P., Martinez, F.J., Marquez-Barja, J.M., 2021. A Review on Electric Vehicles: Technologies and Challenges. Smart Cities 4, 372–404. https://doi.org/10.3390/smartcities4010022
The different types of electric car batteries - Renault Group [WWW Document], n.d. URL https://www.renaultgroup.com/en/news-on-air/news/the-different-types-of-electric-car-batteries/
The impact of electric vehicles on steel and ArcelorMittal [WWW Document], 2021. URL https://automotive.arcelormittal.com/news_and_stories/cases/2017ElectricVehiclesImpactOnSteel