The form of batteries that are really required to realize “EV x sharing”

The form of batteries that are really required to realize “EV x sharing”

Four concepts that are said to change the automotive industry are coined under the term “CASE”.

  • C… Connectivity (IoT)
  • A… Autonomous (autonomous driving)
  • S… Shared
  • E… Electric

It is obvious to everyone that Electric is significantly involved in the technological evolution of lithium-ion batteries (and next-generation batteries such as all-solid-state batteries).

However, the four concepts of CASE do not stand independently, but affect each other.

To introduce automatic driving (Autonomous), it is almost indispensable to use an electric vehicle whose control is easily overwhelming. This is because gasoline vehicles have a large number of parts, and it takes time for the vehicle to react after operating it, making it difficult to perform automatic driving accurately.

In other words, the spread of autonomous driving almost inevitably requires the promotion of electrification. In fact, most autonomous vehicles for which each manufacturer is developing technology are electric vehicles, as far as the press reports.

In addition, realization of automated driving requires IoT and connectedness.

Also, Shared is actually closely related to electrification. The shift from private ownership to sharing also means that the way cars are used will change dramatically.

And that brings about a difference in the performance required for electrification. In that case, the desirable appearance of lithium-ion batteries installed in electric vehicles also changes.

At present, there is often a discussion centered on the “energy density” that is directly linked to the cruising range of electric vehicles, but that is likely to become less important.

In this article, I would like to consider the difference between “EV x sharing” and “next-generation batteries” from the perspective of the battery industry.

What is a “next-generation battery”?

For example, NEDO, which has several Japanese national projects on batteries, issued such a roadmap in 2013.

This is the latest NEDO roadmap as of January 2020.

Although it is a bit difficult to understand because various things are written in fine characters, I list three points of reference, “energy density”, “power density”, and “cost”.

In addition, all of the “innovative batteries” (which can be considered as next-generation batteries) written in the lower right of the upper figure are of the type expected to have extremely high “energy density” Battery.

One example is the lithium-sulfur battery, which was released earlier this month by Monash University in Australia as a research result.


The most important reason why “all-solid-state batteries” mentioned in the previous article (only Japanese version) has attracted attention is “energy density”. Although quick charging, heat resistance, and long life are often taken up as merit, it seems that the most frequently discussed is energy density.

Isn’t “energy density” really a big problem?

In fact, when reading an academic paper on next-generation batteries, words such as “energy density” and “cruising distance” appear in the background of the research at the beginning.

But the real bottleneck in electrification is not energy density (range). If that were the bottleneck, manufacturers such as Tesla, Mercedes-Benz, and BMW would not have been able to commercialize EVs that use lithium-ion batteries today.

The real bottleneck in electrification is cost rather, especially in low-priced cars, where it tends to be rate-limiting.

In addition, for those who use cars that do not normally travel long distances, that will not be a significant bottleneck.

This is because if you don’t want a very long range, you can reduce the amount of batteries and reduce the cost, so it can be cheaper. This is even more so if the vehicle is supposed to be ridden by one or two people, as the battery size can be reduced by reducing the body size.

That’s where Toyota focused on the “micro EV”. That point is explained in detail in a previous article.

As I have explained so far, my opinion is that energy density is not really a problem.

In that case, it is thought that the development of the “next-generation battery” may end up being merely a “kaizen” (improvement) rather than a revolution.

So here’s where the breakthrough in batteries can no longer happen, or not. This is because batteries may become rate-limiting when sharing electric vehicles.

Battery required for “EV” x “sharing”

What really matters in sharing electric vehicles is “life”.

If you own an electric car, you can recover it unless you use it in a crushing way.

Even if the cruising range per charge (= 1 cycle) is estimated to be as short as 200 km, it is 100,000 km if you have 500 cycles, so it can be said that it is not inferior to ordinary gasoline cars. 500 cycles is the shortest life of a commercial lithium-ion battery, but it is still not a concern for personal use.

However, if sharing is used in such a way that multiple people ride around one car, the mileage will increase at a stretch. In that case, it is severe if the battery is not used after several hundred thousand kilometers.

Moving from private ownership to sharing means that ownership moves from the individual to the business side (the lender). This means that the business side has to bear the cost burden when the battery reaches the end of its life.

Then, on the business side, the first thing to think about if you try to control the cost of batteries even a little is the battery life. Even if you endure a little initial cost, it is easier and cheaper to use long-life batteries.

Until now, electric vehicles were sold out, so to be honest, battery life wasn’t an important specification. However, if you are going to share, it is essential that batteries have sufficient energy density and long life.

Rather than the extraordinary energy density of the above-mentioned “innovative battery”, whether the ultra-long life that can support the sharing business can be paralleled with other characteristics (energy density, rapid charging, low temperature resistance etc.) Isn’t it a true breakthrough?

In other words, looking at battery-related reports, it seems that technology development is being performed too much on energy density, but in fact, innovation in other characteristics may lead to the next breakthrough. That is, you need to keep that in one corner of your head.

If you follow the trend of “EV x sharing” from such a viewpoint, there may be new discoveries.