The Slow Death of the Internal Combustion Engine

[Isaac Zackary]

Sorry I'm late to the topic. I started reading the first few pages but will have to start again later.

Anyhow, maybe this point is already made somewhere in here, but... Although the majority of EV's today have combustible batteries, non-combustible batteries do exist. And as far as I understand, even Tesla is trying to develop non-combustible batteries. For an example, they bought out Maxwell Technologies, who have already developed a solid non-combustible electrolyte that promises denser, lighter, longer lasting and cheaper batteries that do not combust under any circumstances.

So in the future there is the possibility of having the choice of buying an EV without anything combustible in it. In fact there have been plenty of EV's, especially from DIYer's that have had non-combustible batteries such as lead acid, NiMh, and LiFePO4.

As far as I understand you can't make gasoline non-combustible. Even if you could, then it would be useless.

[oil pan 4]

Only problems with LiFePO4 is if you charge them much below freezing the batteries capacity is severely damaged then if the battery is discharged while above 120F it's rapidly damaged. Between a winter and a summer improper use could kill over 1/3 of the batteries capacity.
The operational temperature range between too hot and too cold is only around a 100F span.
So LiFePO4 batteries need a lavish and robust thermal management system that can have a lot of energy directed towards it, really plug in hybrid are the application for them since the battery isn't depended on and the engine can be fired up to heat or cool the battery and drive the car as needed.
They're also cheap and don't use any of that slave mined cobalt.

The batteries the leaf uses are much more robust.
The do not charge low temperature cut off is around 0F but may be as low as low as -4F, they will charge at +10F slowly and the upper limit is more like 130F.
Rapid high temperature damage like you see in the LiFePO4 doesn't happen with the LiNiMnCo02 until above 140F.
The LiNiMnCoO2 battery comfort range is more like a 120F span. But they explode if they get poked.

[redpoint5]

That's not the only problem with LiFePO4; it has much less energy density too. It has a lower operating voltage, so you don't get as much energy per volume of battery.

I don't care if batteries get safer. I'm not against improving safety, but if you're in an accident where the batteries caught fire and you can't escape, that was already an extremely severe accident that you weren't likely to survive in the first place.

15 years from now crashes will be a rare thing that is reported on the news rather than a daily occurrence during rush hour that doesn't make the nightly news.

The real enemy of safety is the crashing, not the batteries (or gasoline).

[oil pan 4]

If it damaged the battery enough to make it catch fire then a gas tank would also likely be ripped open or burst. Gasoline all over the place looking for a source of ignition.

[Isaac Zackary]

Personally I'd like to see NiMH make a comeback in the pure EV market. Not sure how long the oil company (was it Shell??) will have the control on it. But the stuff works at practically any temperature without special thermal management, doesn't need to be balanced and isn't flammable. Sure, it's not as energy dense as lithium ion. But it doesn't have to be for some EV applications.

But the point was that if you want a completely non-flammable, non-combustible car sometime in the future, electric seems like it has the real potential of getting there.

But yes. Reduce or eliminate accidents would be top priority in my opinion. One of the reasons car manufacturer's keep making bigger, bulkier and heavier vehicles is for safety. If autonomous controlled driving could eliminate accidents then you could make cars as lightweight as possible without worrying about crumple zones and such.

I just don't know how autonomous driving would work here where I live when there's 6 inches of snow on the road, deer, elk and moose jumping out onto the road and even rock slides.

[oil pan 4]

A leaf battery pack easily puts out 80kw. A NiMH battery the same voltage and same amp hours worth of cells would struggle to put out 80kw and would weigh about twice as much.
Oh and forget about quick charging. NiMH like to be charged slow.
Self discharge is high.
No one owns NiMH they have been around since the 1970s or 1980s.
The early hybrid cars used them.
Looks like the most important NiMH patent was owned by a now bankruptcy chevron subsidiary 20 years ago. The last significant NiMH patent expired around 2010.
It looks like when Toyota and honda started making their hybrids the price of nickel shot up from a few dollars a pound to nearly $30 per pound.
We don't use them because they are heavy, expensive, inefficient.

The only advantage I can think of is they have over lithium is NiMH are highly recyclable.

[redpoint5]

Recyclable isn't important if the materials are plentiful, cheap, and environmentally friendly.

[oil pan 4]

Mining Nickel and rare earths used in NiMH are pretty horrible for the environment.

[redpoint5]

Originally Posted by oil pan 4

Nickle and rare earths used in NiMH are pretty horrible for the environment.

That's exactly what I'm getting at with Lithium ion. The need to recycle isn't there because the materials are cheap, plentiful, and non-toxic to the environment.

You said NiMH has an advantage of being recyclable, but that's not an advantage if the reason is because it has expensive and toxic materials.

[Isaac Zackary]

I don't think it's all that much doom and gloom for NiMH batteries. My Avalon can charge the hybrid battery from near zero to full in the time it takes to make it half way down a mountain pass. That's pretty fast charging in my opinion.

Also I was under the impression that NiMH was less damaging to the environment than lithium ion. But I guess I could be wrong.

On another subject, if I were to add additional battery capacity to my Avalon hybrid, NiMH would be the least hassel, not just because the car is designed to charge NiMH, but because there would be less to do with thermal management and with fire prevention.