Interview with Prof. Maximilian Fichtner
Prof. Maximilian Fichtner is an internationally renowned expert in battery technology. In an interview, he talks about improved battery systems, alternatives to the use of cobalt and the climate advantage of e-cars.
You say that electric car batteries will make great progress in the coming years. What makes you so sure?
I expect leaps in development in two crucial areas. Firstly, in the storage materials that absorb the energy. A lot is happening here, especially on the anode side, where a composite of graphite and silicon could soon replace pure graphite. As silicon has a storage density that is ten times higher than graphite, the energy content of the batteries would therefore increase significantly. Secondly, improvements are being made to battery design. Specifically, future battery systems could hold significantly more storage material while remaining the same size. This is a critical factor in providing longer ranges.
What is the disadvantage of today’s battery architecture?
Current standard design produces battery systems in which the actual storage material only accounts for 25 to 30 percent of the total content. The rest is accounted for by the housing, packaging and additives. We will see great progress here. Future battery systems will be designed more efficiently and the share of storage material could almost double. This would increase the energy content and reduce the costs of production. I am pretty sure that this will lead to a leap in improvements.
What role does the much-anticipated solid-state battery play?
The solid-state battery offers the option of replacing the graphite at the negative terminal with metallic lithium, which would increase the range by 30 to 40 percent. This is why the technology is regarded as the Holy Grail of battery research. I also see opportunities, but uncertainties remain because solid-state batteries do not yet exist in an industrial form. I can imagine other open questions on the cost side, for example.
“The electric car has the best carbon footprint of all drive types in the passenger car sector.”
What do you mean?
Today’s lithium-ion batteries are on a classic, falling cost curve. With the introduction of sustainable cathode materials such as lithium iron phosphate, they have already fallen short of the important benchmark of 100 dollars per kilowatt hour of electricity. This is the magical limit below which an electric car becomes cheaper than a car with a combustion engine. It is not yet possible to say today whether or how quickly this can be achieved with the solid-state battery.
What improvements can car drivers expect?
Electrical ranges of well over 500 kilometres will soon be a matter of course. Even a range of 1,000 kilometres is possible. Overall, the development of the vehicles is on the right track. On the other hand, I see challenges in providing an appropriate charging infrastructure. We need an extensive network of powerful fast charging stations. We need to enable city dwellers without their own wallboxes to conveniently charge an electric car. And we need to standardize pricing when charging on the road. The electric car has the best carbon footprint of all drive types in the passenger car sector – we should therefore ensure that e-mobility prevails.
There is often criticism about mining the battery raw materials cobalt and lithium. Do you see alternatives?
Cobalt is currently mainly used in mobile phone and notebook batteries, as well as in hard and cutting steels. In terms of electric vehicles, on the other hand, a complete exit seems to be possible – and necessary. Not only because of the human rights problem, but also because of the limited reserves. A good alternative is already available in lithium iron phosphate, a material that is cost-effective, sustainably available and non-toxic. The so-called manganese spinel could also be an option. On the other hand, there is not yet a convincing replacement for lithium. However, I also see the situation here as not so critical since global lithium reserves are much greater than those of cobalt. And there are currently alternatives to lithium extraction from salt lakes.
Prof. Maximilian Fichtner is an internationally renowned expert in battery technology. He teaches solid-state chemistry at the University of Ulm and heads the department for energy storage systems at the KIT (Karlsruhe Institute of Technology).
On April 29 Fichtner will take part in the Volkswagen Way To Zero Convention. He will evaluate the strengths and weaknesses of battery-powered e-mobility, drawing comparisons with hydrogen and synthetic fuels. Learn more about the event: convention.vw-newsroom.com.
* ID.4 1ST, 150 kW – combined power consumption (NEDC) in kWh/100 km: 16.2; CO₂ emissions in g/km: combined 0; efficiency class: A+
ID.4 - power consumption (NEDC) in kWh/100 km: 16.9–15.5; CO₂ emission in g/km: 0; efficiency class: A+