The Heart of the Electric Car

22nd Feb 2021

The Heart of the Electric Car

We have been saying for about 150 years that the heart of the car is the engine. Any kind; diesel, petrol, wankel, turbo .... And now that is changing, changing drastically and of course some people don’t like that. The heart of the electric cars, which are (too) slowly but surely conquering the world, is the battery. It’s all about the battery, as an electric motor isn’t something worth talking seriously about at all. Electric motors already have an energy efficiency of around 95%. Clearly, the electric motor and its performance are also technologically improving, but compared to the battery, it is a completely insignificant technological element; as with classic cars for example “exhaust”.

I come from Slovenia, a small country sandwiched between the Alps and the Adriatic Sea. From a country that has been close to war all along and that has given the world quite a large number of scientists and inventions. I will not even mention the number of athletes that come from Slovenia. We also have an excellent National Institute of Chemistry, which has been developing batteries for decades. They were involved in the development of lithium batteries more than thirty years ago and were the best in the world at the time.

Maybe for the beginning; why did the batteries even start evolving the way they did?

Simply put, for Japanese cameras, the classic AA batteries were far too weak. The cameras would only work for a few minutes. And when the batteries were developed for cameras, the development of laptops and mobile phones followed quickly.

And then Elon Musk put these batteries in the cars.

There have been attempts before to make electric cars with classic lead-acid batteries, but that was merely Sisyphus ’work. The development of real electric cars could only begin after lithium-ion batteries were sufficiently developed.

Current research at the National Institute of Chemistry is led by Dr. Robert Dominko. He is extremely busy lecturing around the world, as he is one of the most prominent experts in battery chemistry.

If you are working in electromobility in Slovenia, you have no chance not to meet him. He is not a classic scientific genius as we know them from the movies, he does not have glasses with the thickness of the bottom of a whiskey bottle, he does not speak in scientific gibberish, which could only be understood by a few scientists like him. He is simple, serious, likeable and above all ingenious.

“Knowledge about batteries is increasing among the general population,” he began the conversation before I even asked him anything. This, too, is not a feature of staunch chemical geniuses. “Sometimes the range of questions was much wider, journalists were mostly interested in the range of the electric car. We have obviously passed this phase. There are still some safety questions, but these are also becoming increasingly rare. However, safety is still something that we must continue to take seriously.”

“But aren’t you afraid for your job. Information has leaked from Tesla Motors that their latest battery will have a lifespan of 1 million miles, which in average European conditions means about 100 years!?”

“By no means, we are just at the beginning of battery development. Neither I nor my successors need to fear for jobs, we still have a lot of work to do. We are researching new materials to replace the current ones; we are researching new electrolytes that are an extremely important part of the battery. It may sound like science fiction, but we are also looking into and studying biomaterials. Right now, we have a colleague at the institute who is doing a doctorate in this topic. Our institute has also been cooperating with the Japanese Honda for a long time, we are developing a prototype battery for them, and the building block for it is supposed to be magnesium. In short, there will be a lot of work for us in the future!”

“There are a lot of myths about safety of batteries, that they are toxic and that the Chinese will simply throw them into the sea when they are no longer usable, that production of batteries is so energy consuming and that for batteries production they emit much more CO2 into the air than a diesel car releases in its lifetime. And that every battery “dies” after two years, saying that they already know, because it’s the same with phones. How could you comment on all these rumours?”

“The best lie is the one that contains some truth. Of course, lobbies working in favour of the oil industry take advantage of such news. We talked about the battery for 100 years. It should be noted that batteries will have three lifespans in the future. The first will be in bigger, more powerful cars. When the battery loses some of its features, it will be moved to a smaller, cheaper city car, where it will be able to serve the owner well for a few more years, and then, the battery will live to see its third life as an energy storage in a home.

We know how to decompose the battery effectively, but there is no need to industrialize recycling for now. When the need arises, there will also be companies that will do that, as it will be very worthwhile for them. There are a lot of valuable materials in batteries that would be foolish to throw away, such as copper and cobalt. So, you can trust me that the batteries will not be thrown into the sea. I haven’t heard anyone throw gold into the sea (by the way; there is also some gold in the batteries) ... As for the energy consumption for production, it is true that a lot of energy is used, both for the production itself and for decomposition. However, energy is expensive, and factories are striving to reduce this cost. We know that to make 1 kWh of battery, we release about 100 kilograms of CO2 into the air.

(This figure is the largest I know, and most factories release much less CO2 into the air to make a 1kWh battery. N/A.)

Of course, the carbon footprint is declining due to the use of more and more renewable sources, but energy consumption is still quite high. This also applies to Tesla’s factory in Nevada. They use a lot of energy there mainly because they have to pump a lot of water, which they do not have in the immediate vicinity. However, it is also true that they get all this energy from photovoltaics. There is no point in losing words about life expectancy of batteries anyway, as we have talked about 100 years before. Car manufacturers still give long warranty on batteries, which speaks of their certainty in longevity of batteries lifespan.”

“However, batteries are still becoming more efficient, and at the same time cheaper. Where else can we go both technically and in terms of price?”

“At the moment, we have an energy density of about 300 Wh per kilogram of weight. In the first electric cars, the density was much lower. However, manufacturers have made the greatest progress in battery engineering. Temperature is a major factor in battery degradation. And a good battery heating / cooling system is very important. The use of cobalt, which is an expensive and rare element, has been significantly reduced in batteries. I think we are also approaching solid electrolyte batteries, the so-called “solid state” batteries. With a higher energy density, which will be somewhere between 400 and 450 Wh per kilogram, the degradation of the battery will be slower, and the lifespan will be extended. Solid state batteries were first made as early as 1972, but at that time they did not yet have as much knowledge on the operation of metallic lithium as we have today, and the batteries were not stable.

As for the price; it is now somewhere around 200 euros for 1 kWh, but we can expect the price to drop to 100 euros for 1 kWh, some even claim the future price to be around 70 euros for 1 kWh. The higher the production, the lower the price. The question, however, is always, what are the real costs of production and what is the final price; price is always a marketing element. “

“You said you were working with Honda, but I have a feeling that the automotive industry pretty much resist making electric cars. Do you have that feeling too?” I challenged Dr. Dominko a little.

“As for the automotive industry, you’re probably a bigger connoisseur than I am. We have been working with Honda for many years and I have a feeling that they are extremely serious when it comes to the transition to electromobility. But you are probably right when you claim that the car industry does not want to move quickly to electromobility. The profits from the production of ICE cars are extremely high, they will also lose a lot in the after-sales with the arrival of EV, so they are in no hurry. “

“This is probably also the reason why European car manufacturers would like to see plug-in hybrids on the roads in particular,” I couldn’t move quickly away from this topic, although it was obvious that he didn’t like to talk about it ...

“Again, I can talk mostly about Honda; they have already announced the cessation of development of all ICE engines. This means that in a few years, ICE engines will by no means compete with electric propulsion. Especially with the rapid development of batteries that we are witnessing. I don’t know if a plug-in hybrid is needed if you have a battery that can carry you for 300, 400 miles without charging. We know that Europeans do about 25 to 30 miles a day on average. For two or three times a year, when you do 200 miles or more in one day, it really doesn’t make sense to think about anything other than clean electricity. “

“Speaking of travel; what about fast charging. Is it really more stressful for the battery and is the degradation greater?”

“What is fast charging for you?” Dr. Dominko challenged me this time.

“For me, fast charging is, say, 150 kW of power.”

“That’s not fast charging at all. For me, quick charging means if the battery is charged in six minutes, which of course already exists. But to explain the charging speed first. Experts use the letter “C” for this. And it goes something like this; if the battery is 50 kWh in size and is charging at a speed of 50 kW, then that is 1C. The battery should therefore theoretically be charged within 1 hour. These are not problematic speeds. It is true, however, that battery degradation also increases with charging speed. The easiest way to explain this is in a “sporty” way. Imagine a football stadium. When people slowly come through the door at the start of the match, there are no problems. However, when everyone wants a beer as soon as possible during half time, there is a crowd at the door. So, some get stuck, some prefer to turn around and wait for the crowd to pass, some just give up and wait, others scramble, in short, everything is happening. It’s the same with charging, the faster it is, the greater the chance that the material will degrade.

However, now the battery management system (BMS) in car is so good that, it determines the charging speed itself, depending on the condition of the battery. Most of all, it depends on the temperature and charge. We talked about beer after the match; even if the doors are no longer crowded, the bar is and you can’t get your beer as fast as you would like, so you just have to wait a bit.

However, you will damage the battery the most if you completely discharge it. If you look after the battery and use it between 20 and 80 percent of the total capacity, the battery will last a very long time! Probably longer than the car itself. That is why all car manufacturers state the charging time at fast charging stations up to 80 percent.”

This is also best for the speed of the travel itself. Over the thumb; to charge the battery from 80 to 100 percent, you would spend about the same amount of time as to charge it from 20 to 80 percent. It therefore just doesn’t pay off to wait for your battery to fully charge as you just waste too much time! (N/A)

“Speaking of battery degradation,” Dr. Dominko continued; “We still have a lot of reserves when charging, because at the moment we know what is happening with the whole battery pack, but not what is happening in individual battery cells. If we could have our own control unit in each cell, the degradation of the battery (even when we are not charging) could be much slower. Instead of a million miles, such a battery could last, say, two times that. However, this is not worth it yet, and the problem is also in the size of the batteries. At the moment Tesla uses a lot of small cylindrical batteries in its battery packs and such a system would be very expensive. If, for example, battery cells were larger and there would consequently be less of them, such a system, supported by artificial intelligence, could give us really great results. But as said; the commercial fast charging as we know it today (Between 50 and 150 kW. N/A) does not destroy the battery very much, however it is much better to charge the car on slow chargers, or at home. Because of the price of charging itself as well. However, if we really want to have a charging speed of 10C, then we will also have to change the chemical composition of the battery. This comes into play with other means of transport, such as city buses or planes, but in those cases, it is better even to consider super capacitors. For passenger cars, in my opinion, the charging speed of up to 150 kW is completely satisfactory!”

And Dr. Dominko is - in my many years of experience - absolutely right! If we have a car with a capacity of about 250 miles and we drive at a speed of 70 miles per hour, that means we can drive with this car quite normally for about three hours. After three hours, it is healthy to stop for a visit to the toilet, drink a cup of coffee, and a have snack. We usually spend 30 minutes doing these chores. With 150 kW charging, the car is additionally charged for another 60 to 70 miles. This means we can drive at least 300 miles with a 30-minute stop. So, do we really need even bigger batteries and even faster charging?

Yes, we need them because some people still want the charging to be faster and batteries to last longer, but there are very few of them and they will pay a reasonably higher price for both: the car and the charging itself. For 99.8 percent of Europeans, however, what I have described above is quite sufficient.

Therefore, ladies and gentlemen; the batteries are already great, and they are getting better by the day. Do not fear batteries and consequently electric cars. Just go for it!

Article by Primoz Lemez


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