One of the biggest drawbacks of electric cars is the curb weight, with the main culprit here being the battery. There are many ways to reduce this amount of weight, but some risks are involved, and it seems that Elon Musk, CEO of Tesla, is not willing to take that chance.
What Kind of Batteries Are There?
In the context of electric car batteries, there exist pouch, prismatic and cylindrical batteries, varying in size and electric energy capacity. Tesla has used cylindrical battery packs ever since they introduced their first vehicle, but there were instances of them using the prismatic form as well. The key point here is that Tesla never used pouch batteries, and it seems that they will never use them either. Despite the obvious advantage of lowering the curb weight of the entire battery pack, Elon states that this is the most challenging format of battery to engineer properly, and can cause major damage when something goes wrong.
Pouch batteries have never dealt with thermal energy runaway properly, so there is a strong chance of catastrophic battery failure, and therefore, risk of injury and/or death. This would not be so surprising if there were no other electric vehicle manufacturers making use of the pouch battery format, without any major incidents so far.
Pouch batteries were introduced in 1995, and its strongest feature was its ability to fill up available space most efficiently, occupying 90 to 95 percent of it. Without the metal enclosure, the battery cell can easily be designed to fit the case. Since there is no aluminum or steel casing enclosing the battery cell, it has a tendency to bulge and stretch to a certain point. Obviously, Elon must be referring to cases where the battery might actually explode and expose the environment to the chemicals found within. Hopefully, we will get an update on this claim soon.