Basic information about batteries

What you should know about batteries in electric cars.

Which battery types are used in electric cars?

So far, lithium-ion batteries have primarily been used in electric cars. These store energy in chemical form and then release this energy as electrical energy when driving. In principle, batteries in electric cars do not differ from the batteries that are used, for example, in smartphones. Since an electric car requires much more energy, the batteries are divided into modules, which in turn consist of individual cells.

The LFP battery is a special type of lithium-ion battery in which the electrode is made of lithium iron phosphate instead of lithium cobalt. Therefore, in the production of LFP batteries, the rare cobalt can be dispensed with, which makes them cheaper. However, LFP batteries are less resistant to cold. When the ambient temperature drops, an LFP battery quickly loses power. LFP batteries have recently been frequently mentioned in connection with Chinese manufacturer BYD. The manufacturer calls its batteries "blade batteries" and is to deliver them from the 2nd quarter of 2022, especially to Tesla. According to BYD, the special feature of the blade batteries is the extremely high number of 3,000 possible charging cycles.

A new battery technology will probably be launched at the end of 2023. The so-called sodium-ion battery dispenses with expensive raw materials such as lithium, copper, nickel and cobalt. The necessary raw materials for sodium-ion batteries are easier to obtain and to process with less energy. In addition, sodium-ion batteries are less flammable, better fast-charging and more powerful at low temperatures. Overall, this new form of battery is more sustainable and cost-effective to manufacture.

The third battery type is also still under development. The so-called solid-state batteries are expected to be ready for the market at the end of 2022. Solid-state batteries are less complex than lithium-ion batteries, offer a higher energy density and are significantly cheaper to manufacture. Solid-state batteries will also be smaller, so that the range of the electric car will increase significantly. The Chinese electric car manufacturer Nio has announced a solid-state battery that will provide a range of more than 1,000 km.

The German Fraunhofer Institute is working on a battery with SALD technology,which should also ensure extreme ranges and can also be charged about five times as fast as a current lithium-ion battery. We are researching new battery types for electromobility worldwide. Until the new batteries reach market maturity, the lithium-ion battery will be further developed, so that progress in range, charging time and environmental compatibility can also be expected in the near future.

What problems arise in the production of batteries for electric cars?

Although different studies come to different conclusions, the CO2 produced during the production of batteries is considered a major problem. So before an electric car gets on the road, it already has a large so-called "CO2 backpack" in its luggage. Compared to cars with combustion engines, however, this will become smaller and smaller over time because no CO2 is emitted during operation of the electric car.

How long does the battery last in the e-car and what happens to it when it is empty?

An e-car battery with lithium-ion technology can be charged about 1,500 to 2,500 times. With an average range of about 200 km per charge, this results in a mileage of 300,000 to 500,000 kilometers. More modern batteries should already be able to be charged up to 3,000 times. Over time, however, the batteries lose capacity, so that at the end of a battery life only 70 to 80 percent of the original capacity is available.

The car manufacturers usually give a warranty of 8 years on their batteries. If a battery for an e-car no longer has enough capacity, it can be used for other tasks or it is recycled. In the so-called "Second-Life" application, the battery can be used e.B. as a power storage in private households for another 10 to 12 years, as the battery is significantly less stressed here due to more uniform charging and discharging phases.

Another option is the recycling of batteries, which, however, is currently still largely unprofitable due to the energy required. There are two approaches to recycling car batteries: melting or mechanical processing. The recycling rate for processing is 90%. The CO2 backpack of the battery could be reduced by about 40% with this type of recycling.

Previous battery recycling plants are located in Bremerhaven, Brussels and Salzgitter. Volkswagen has been operating the pilot plant in Salzgitter since the beginning of 2021 and can process 3,600 batteries there per year. A typical battery of an electric car contains a lot of aluminum, plastic and steel. In addition, about 4 kg of lithium, 11 kg of manganese, 12 kg of cobalt, 12 kg of nickel and 33 kg of graphite can be recycled.

Currently, a large part of the battery for electric cars is still in use either in the electric cars themselves or in second-life applications. It will therefore take some time before the recycling of batteries in larger quantities will begin.

How heavy are the batteries in electric cars and where are they located?

In modern electric cars, the battery housings with the individual battery modules are located in the vehicle floor. The battery housing protects the batteries in the event of an accident and the installation in the vehicle floor ensures a low centre of gravity due to the high weight of the batteries, which benefits the driving behaviour. The weight of an e-car battery is between 250 kg and 700 kg.