Which battery is used in Electric vehicles?
The quest for more environmentally friendly transportation is driving all vehicle manufacturers to electrify vehicles used for road transport of people and goods. When compared to the technologies used just a few years ago, this is a global revolution.
The thermal engines, which are probably resisting within a few years, will have to give way to the new electric drive. The latter is requiring huge investments on the infrastructure front, but also on the part of builders. Within the supply chain dedicated to electric mobility, the big problem of batteries is grafted, both in terms of their construction and in terms of recovery at the end of their life. Yesterday with nickel and cadmium or lead, today with lithium, tomorrow by perhaps using graphene… traction batteries for electric cars are evolving for evermore lightness, autonomy, and cleanliness.
Lead-acid batteries have been used in the automobile for more than 150 years. The first electric traction tests on vehicles were carried out a few years earlier, with accumulators that weren't recharging: big batteries, in a way. Even today, lead-acid batteries are fitted in thermal models, as well as electric ones, to supply equipment and accessories. Milk delivery trucks in Britain have used this technology for their propulsion for decades. Usable over a temperature range between -20 and 60 ° C, lead batteries do not have the memory effect but must be changed after 20,000 to 40,000 km, depending on use. Naturally present in nature, lead only creates pollution and public health problems through human activity. Classified as CMR (carcinogenic, mutagenic, and reprotoxic), it is dangerous for the nervous and digestive systems of living beings which can easily ingest it when it contaminates water in the form of undetectable particles.
No car manufacturer today offers an electric car equipped with NiCd batteries. It is European Directive 2002/95 / EC, relating to the limitation of the use of certain hazardous substances in electrical and electronic equipment, implemented in July 2006, which prohibits it. In the process, a recycling channel was organized which would almost make you regret the disappearance of its accumulators with multiple qualities. Reliable if well used and maintained, accepting rapid recharging, they have a long lifespan that can be calculated in decades. It's simple: they only wear out with use, unlike lithium batteries. Unloaded, they can be stored for very long years without any damage.
Sodium-nickel chloride batteries (Zebra)
Present at the heart of a few electric car models developed by manufacturers of modest size, Zebra batteries (Zeolite battery research Africa project) were used from the end of the 1990s until very recently, as an alternative to NiCd technology. It was a question of benefiting from better autonomy. Zebra batteries do not represent a particular environmental problem ... on condition of obtaining nickel, aluminum, and sodium under acceptable extraction conditions. On the other hand, they must be reserved for operation in fleets in almost permanent rotation, because their internal temperature must always be maintained between 270 and 350 ° C, hence a very significant self-discharge-self-consumption phenomenon (more than 10% loss per day). In the latest versions of these accumulators, this resulted in several days of waiting to use them again. In the first, it was the pure and simple death of the drums. Vehicles carrying such accumulators had to be connected to the electrical network when they were not in service. While they have abandoned electric passenger cars in recent years, programs for the development of clean buses have continued to build on them.
Lithium-ion batteries have been flooding the electric vehicle market for a few years in all forms of gear, from assisted bicycles to cars. The first work on these accumulators dates back to the 1970s, thanks to researchers who discerned the full exploitable potential of this solid and particularly light metal. It was not until 1985, with the first lithium-ion battery produced, that we can observe the benefits of this technology, among which a high voltage and the absence of a rapidly destructive memory effect. Sony began marketing in 1991. The ideal operating range for lithium-ion batteries, between -20 and 65 ° C, has favored its meteoric rise in electromobility. The ratio between their energy density, their weight, and the price ranks them among the best on the accumulator market. No wonder they are found in most electric cars currently in dealerships, including the Nissan Leaf, BMW i3, Tesla Model S and X, and so on. The use of lithium-ion batteries has raised several controversies, including their recycling and environmental problems in lithium extraction. For the first, the sector for their recovery was indeed created quite recently, the need not being present until then. It now has several dedicated factories around the world.
Others and derivatives
Different manufacturers are trying out other combinations, sometimes applied here and there, but still too anecdotal to talk about in detail. It would also be difficult to do so because little precise information is filtered most of the time. We are talking about lithium-titanate, lithium-iron-phosphate, lithium-air batteries, etc.
Some examples: The Chinese BYD e6 carries lithium-iron batteries, the Bee-Bee lithium-iron polymer blocks. We expect a lot from graphene, especially to obtain relatively affordable batteries for autonomy that can be described as impressive. Fisker had communicated in this direction for his future productions, before returning however to more traditional technology.