LFP batteries: The new Iron Age

LFP batteries: The new Iron Age

While the engine was the heart of every car in a combustion engine, it is the battery in an electric car. The large battery, which is usually stored in the vehicle floor, is largely responsible for the range, charging time and power. They are also by far the largest cost factor for manufacturers. Until now, lithium-ion batteries were considered the measure of all things. Tried and tested millions of times in cell phones, laptops, toothbrushes, headphones and even electric cars. But in automotive circles there has recently been increased talk of lithium iron phosphate batteries, also known as LFP for short. Volkswagen wants to use this battery technology in models below the ID.3. Ford will be using LFP technology in North America next year on the Mustang Mach-E models and later on the F-150 Lightning. Tesla is already one step further and has already installed and sold LFP batteries in Model 3s - first in China, now also in Europe. First of all: It is not a new miracle battery, but a technology that has clear advantages and disadvantages.

Lithium iron phosphate batteries were developed at the end of the 1990s and are also known as LiFePo4, LFP or LEP. For a while, these were very popular in model racing and also as motorcycle starter batteries, as they are much lighter compared to lead-acid batteries. One of the biggest advantages in direct comparison to lithium-ion technology is that the cells do not contain rare materials such as nickel, cobalt or manganese. This makes the cell more sustainable and also cheaper. Ford states the price advantage over the lithium-ion cell is around ten to 15 percent. Another strength of the LFP cell is its cycle stability: While lithium-ion batteries have a service life of around 3,000 cycles (complete discharge to charge), an LFP cell can withstand up to 10,000 cycles until its capacity has fallen to 75 percent - the general wear limit for batteries. In addition, lithium iron phosphate batteries are considered to be less sensitive to temperature and are very robust and safe. The risk of fire and explosion should be lower. And they deliver high, stable discharge currents. And because the batteries do not contain any rare raw materials, all metals in them are 100 percent recyclable. Only the electrolyte cannot be reused. This means that the recycling rate is almost as high as for a normal lead-acid battery - an enormous environmental benefit.

Sounds wonderful, so why haven't we already started using LFP batteries? Because their energy density is significantly lower than that of lithium-ion batteries. This means that in order to achieve the same range with an electric car with LFP batteries, you need more cells, which are then heavier, more voluminous and their price advantage may then be equalized again. To clarify: the usual power density of a lithium-ion battery is 180 Wh per kilogram. That of the LFP batteries is only 90 to 110 Wh per kilogram. If range and low weight are required, the lithium-ion battery clearly and clearly beats the LFP batteries. Although at a higher price and with lower cycle stability, LFP technology is currently at a disadvantage here.

And why do Tesla, VW and Ford still rely on LFP technology? There are several reasons for this. First: The batteries are cheaper, which makes it more likely to be able to offer cheaper electric car models. Secondly: Since less expensive and rare raw materials are used, their procurement is easier and in larger quantities, which means that the ability to deliver is more stable. Thirdly: For smaller car models, where maximum range is not important, LFP technology currently offers an attractive price-performance ratio for car manufacturers and the argument of greater safety and service life is on its side. Tesla boss Elon Musk has apparently said that an LFP battery should be sufficient for 75 percent of electric cars in the future. That's why Tesla is already using battery technology in the Model 3. The initial difficulties were not due to the battery hardware, but to the vehicle software. As a result, when buying a car in the future it might not be: petrol or diesel, but lithium-ion or lithium iron phosphate battery?