Electric vehicles are becoming increasingly popular, and governments are even encouraging their use through legislation. Here we look at what differentiates these vehicles from fuel-based cars and what battery technologies power them.
electric vehicle market today
In an electric vehicle or hybrid electric vehicle, the electric motors are powered by a rechargeable battery. Their use is increasingly being adopted by many countries.
An executive order signed by US President Joe Biden requires electric vehicles to account for 50% of all new car sales by 2030. A similar requirement that electric cars account for 40% of all sales applies in China, the world’s largest electric vehicle market. In addition, the European Union wants to have at least 30 million emission-free vehicles on its motorways by then.
There are currently an estimated 5 million electric cars in circulation in China, making it the country with the most electric cars. With around 1.77 million cars, the USA is in second place, 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 the weight.
The main 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 EV 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 electricity. Lithium-ion batteries are more convenient to use in electric vehicles because lithium-ion batteries offer higher energy densities compared to lead-acid or nickel-metal hydride batteries, which allows battery size to be reduced while maintaining storage capacity.
Safety is the main reason for using manganese in lithium-ion batteries. Due to its increased energy density and reputation for stability, manganese is known to increase capacity and improve range. In addition, manganese reduces the flammability of electric vehicle batteries, which is a problem with cobalt-containing lithium-ion batteries.
Cobalt helps extend the life of batteries, which manufacturers typically guarantee for eight to 10 years, and it also guarantees cathodes won’t quickly overheat or catch fire.
Graphite plays a crucial role in the anode that stores lithium ions. Most commercially available lithium-ion batteries use graphite because of its good cycle stability and energy density.
Steel offers the best balance of strength, weight reduction, performance, cost and environmental impact. Steel is the material of choice for today’s automobiles and will continue to be the material of choice for vehicles in the future.
Electric vehicle batteries contain nickel, jet engine turbines use nickel alloys, and passenger trains and subways use nickel-containing stainless steel. Materials containing nickel provide improved corrosion resistance, reliable and effective electrical and spark systems.
What types of electric vehicle batteries are there?
The most common electric vehicle battery chemistries 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 in hybrid cars instead of lithium-ion.
Apart from the different types of chemistry, there are different formats for electric car batteries: cylindrical, prismatic and pouch cells. Cylindrical cells are the cheapest to manufacture, prismatic cells can store more energy, deliver more power, and have better thermal management, while pouch cells use space more efficiently and deliver the most power.
There are growing concerns about the continued supply of these raw materials for the manufacture of electric vehicle batteries. By considering the resources available on the planet and our ability to extract them inexpensively with available technology, we can estimate whether supply can meet demand in the future.
According to analysts, there could be a potential shortage of global mining capacity to extract the amount of raw materials needed to meet the projected demand for electric vehicles.
There are forecasts that the cobalt content could drop significantly from 200 g/kg to about 60 g/kg dry cell weight. For this reason, Tesla is trying to produce cars that are about $10,000 cheaper by using cobalt-free batteries. There is currently no evidence that lithium will become scarce in the near future, but environmental problems related to poor lithium battery disposal remain.
What is the future of batteries for electric vehicles?
Electric vehicles seem to be here to stay as their demand continues to grow. Research and development by various companies are significantly improving the performance of electric vehicle batteries by reducing production costs, increasing their performance and improving their range.
For example, solid-state and liquid-air battery technologies are being explored as alternatives to Li-ion batteries. Solid-state batteries use solid ceramics instead of electrolyte ions to carry electricity, and are expected to charge faster, contain more energy, and cost less to manufacture. Liquid-air battery technologies have higher energy densities and could have cheaper and longer-lasting components. We could see them circulating in the next ten years.
Other approaches, such as manufacturing recyclable battery cells, could go a long way in relieving pressure 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, MXE, 2022. Rising Demand for Lithium Ion Batteries, Manganese Industry Expert Report [WWW Document]. GlobeNewswire Newsroom. 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. Explanation: Cost 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, TW, 2021. FACT SHEET: President Biden announces steps to advance American leadership 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]. laser ax 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
The role of nickel in transport | Nickel Institute [WWW Document]2022. URL https://nickelinstitute.org/en/about-nickel-and-its-applications/nickel-and-transport/
pvEurope, 2021. Electric vehicles: – Number of electric vehicles worldwide rises to 10.9 million – pv Europe [WWW Document]. URL https://www.pveurope.eu/e-mobility/electric-vehicles-global-ev-count-climbs-109-million
Sanguesa JA, Torres-Sanz V, Garrido P, Martinez FJ, Marquez-Barja JM, 2021. A Review of Electric Vehicles: Technologies and Challenges. Smart Cities 4, 372-404. https://doi.org/10.3390/smartcities4010022
The different types of batteries for electric cars – Renault Group [WWW Document]and 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