I’d prefer something that isn’t as dangerous as Lithium-Ion.
There are several different lithium ion chemistries, each with different safety profiles.
The spicy pillow bulge comes from delamination, which can be prevented with more rigid cell containers. Delamination itself is dangerous because it changes the electrical characteristics of the battery in a way that increases the risk of thermal runaway, where the increased heat speeds up the reaction that causes more heat, in a feedback loop.
Another related danger is the actual flammability of the electrolytes and cathode/anode materials. Several of these chemicals can react with oxygen, especially when hot, to cause intense fires or explosions. And these batteries tend to already contain their own oxygen, so that the fires can’t be quenched.
So the engineers needs to design cells that are more physically resistant to physical deformation, to implement safety features like current interrupt devices (that disconnect the internal cells when certain conditions are met), use chemistries that don’t have as high a risk of thermal runaway to begin with, and use chemistries that don’t rely on flammable components.
Many lithium ion chemistries already accomplish most of these. In recent years, lithium iron phosphate batteries (LFP) have been taking over on car batteries, because they’re much safer on all these fronts: they can withstand much higher temperatures before hitting thermal runaway, and the characteristics of thermal runaway in an LFP battery are more subdued (the oxygen in an LFP battery is more tightly bound in a crystalline structure so that fewer oxygen molecules jump out to feed an ongoing fire).
And as it turns out, LFP is cheaper than the other common Lithium Ion battery chemistries. So the incentives to use this chemistry has caused it to jump ahead in market share in vehicles.
People are working on it. Safety is obviously important. But lithium itself isn’t necessarily any more dangerous than anything else.
There are several different lithium ion chemistries, each with different safety profiles.
The spicy pillow bulge comes from delamination, which can be prevented with more rigid cell containers. Delamination itself is dangerous because it changes the electrical characteristics of the battery in a way that increases the risk of thermal runaway, where the increased heat speeds up the reaction that causes more heat, in a feedback loop.
Another related danger is the actual flammability of the electrolytes and cathode/anode materials. Several of these chemicals can react with oxygen, especially when hot, to cause intense fires or explosions. And these batteries tend to already contain their own oxygen, so that the fires can’t be quenched.
So the engineers needs to design cells that are more physically resistant to physical deformation, to implement safety features like current interrupt devices (that disconnect the internal cells when certain conditions are met), use chemistries that don’t have as high a risk of thermal runaway to begin with, and use chemistries that don’t rely on flammable components.
Many lithium ion chemistries already accomplish most of these. In recent years, lithium iron phosphate batteries (LFP) have been taking over on car batteries, because they’re much safer on all these fronts: they can withstand much higher temperatures before hitting thermal runaway, and the characteristics of thermal runaway in an LFP battery are more subdued (the oxygen in an LFP battery is more tightly bound in a crystalline structure so that fewer oxygen molecules jump out to feed an ongoing fire).
And as it turns out, LFP is cheaper than the other common Lithium Ion battery chemistries. So the incentives to use this chemistry has caused it to jump ahead in market share in vehicles.
People are working on it. Safety is obviously important. But lithium itself isn’t necessarily any more dangerous than anything else.