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Designing better batteries for electric vehicles

news.mit.edu

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Re: Designing better batteries for electric vehicles

#21

Post by qzw »

pjc50 wrote: post #16
inglor_cz wrote: post #13

Earlier quoted context omitted.

"It happens relatively rarely. Nowhere near enough for this to be a concern." You are too dismissive. Not every fire is created equal and putting out battery fires is much harder than putting out gas/diesel fires. Also, EVs sometimes go up in flames when at rest , which, short of deliberate arson, is not a failure mode in ICE cars. ICE cars will generally catch fire underway, far enough from other cars, thus limiting…

Catching fire at rest is a risk for ICE cars: https://www.autosafety.org/bmw-recalls-1-million-vehicles-fi...

Yup, had an ICE car that was part of a recall for risk of fire when parked. The letter I received suggested not parking inside a garage until the repairs had been completed.

Re: Designing better batteries for electric vehicles

#22

Post by jillesvangurp »

lithium_throw wrote: post #17
jillesvangurp wrote: post #9

Earlier quoted context omitted.

ICE cars catch fire all the time. But when an EV catches news, it's major news. It happens relatively rarely. Nowhere near enough for this to be a concern. Interestingly, some rare earths used for EVs are also used for ICE cars and fuel production. For example cobalt is used for getting rid of sulfur in pretty large quantities as part of the oil refining process. The difference is that with EVs, recycling is both fea…

>For example cobalt is used for getting rid of sulfur in pretty large quantities as part of the oil refining process. I don't know why this piece of misleading information is recently circulating so much. By far the most common usage (63%, in 2020, and having grown from 20% in 2006)[1] of cobalt is for lithium battery electrodes (and that is despite the fact that EVs make up a miniscule percentage of cars on the road…

It's not nothing; so it isn't misinformation. Also there are many other rare earths used for cars of course. The point here is that ICE proponents get all green and hippy like when it comes to EVs but are not willing to talk rare earth sourcing when it comes to ICE engines, fuel production, etc. It's called selective bias. The reality is that ICE vehicles contain a wide variety of materials. Ice vehicle recycling is mostly focused on extracting steel and aluminium however.

Cobalt specifically is also becoming less relevant for EVs in any case because more recent batteries use less of it; or none at all in some cases. Like for example the solid state batteries discussed in the article.

Regarding recycling, Tesla is working with third parties as well as working on in house expertise:

https://electrek.co/2019/04/16/tesla-battery-recycling-syste...

You need economies of scale for battery recycling to become more significant. One minor challenge here is that batteries seem to last a lot longer than people expected a few years ago. Supply of used up batteries is simply not there yet. Mostly the industry is still focused on recycling batteries from laptops, phones, etc. So, not an urgent issue for Tesla to be working on yet. But there are of course plenty of startups in this space as it is such an obvious thing to start doing in the next decade. J.B. Straubel, the Tesla co-founder, just got a nice investment of 700$ million for one of those companies. So, very practical and lucrative apparently.

Re: Designing better batteries for electric vehicles

#23

Post by happosai »

pigeonhole123 wrote: post #18
Thlom wrote: post #15

Earlier quoted context omitted.

An airport parking facility burned to the ground in Norway a couple of years ago because an ICE car went up in flames while parked.

And ignited the impossible to extinguish electric car batteries in its vicinity

Extinguishing EV fire is not hard, you just just need a lot of water. The problem is that it will re-ignite after a while. So you can't just leave it after that, you need to move the wreck to a safe location and have some firefighters wait until if reignites, drown it in water and repeat.. The alternative is to drop the car in a container of water, but has it's own drawbacks.

It really depends on what kind of risks we willing to accept. Since people sleep well in homes with pipelines of explosive gas

https://www.dallasnews.com/news/2021/07/20/plano-home-explos...

I don't think EV fires are going to stop their adoption.

Re: Designing better batteries for electric vehicles

#24

Post by csours »

baybal2 wrote: post #6

Note, the mass of an anode is at most 15% of mass of the modern battery cell. All "metallic" lithium cells still need some mechanical structure to hold lithium. So, at most you will get a half of the mass of graphite, given that graphite is already a quite lightweight material. For the cost, the second most expensive part in the cell after the cathode is the separator. Close to a third of cell's cost can be the separ…

From where do the Korean battery manufacturers source their separators?

Re: Designing better batteries for electric vehicles

#25

Post by guerby »

lithium_throw wrote: post #17
jillesvangurp wrote: post #9

Earlier quoted context omitted.

ICE cars catch fire all the time. But when an EV catches news, it's major news. It happens relatively rarely. Nowhere near enough for this to be a concern. Interestingly, some rare earths used for EVs are also used for ICE cars and fuel production. For example cobalt is used for getting rid of sulfur in pretty large quantities as part of the oil refining process. The difference is that with EVs, recycling is both fea…

>For example cobalt is used for getting rid of sulfur in pretty large quantities as part of the oil refining process. I don't know why this piece of misleading information is recently circulating so much. By far the most common usage (63%, in 2020, and having grown from 20% in 2006)[1] of cobalt is for lithium battery electrodes (and that is despite the fact that EVs make up a miniscule percentage of cars on the road…

"kg per millions of litres of fuel" we consume lots of fuel, if 1kg per million liter that's between 5 and 6 thousands metric tons of cobalt per year. number two cobalt producer is russia with 6 thousand metric ton per year (first is DR Congo with 100 thousand metric ton).

Also rare earth are present in fossil fuel cars (Catalytic converter amongst other pieces):

https://engineering.stackexchange.com/questions/13757/what-r...

But nobody ever talked about these before EV were a thing.

Re: Designing better batteries for electric vehicles

#27

Post by sokoloff »

h4vot wrote: post #14
adrianN wrote: post #8

Earlier quoted context omitted.

EVs can cover almost all usecases for a large number of people. I think that counts as "pretty good", the main issue seems to be cost and lack of charging infrastructure for people without a garage.

Husband got a Jag i-Pace a few months ago. 400 km range. Haven't even bothered to get the fast charging equipment installed yet at home just give it 240 volts at night. Its never been under 50%. I think for the vast majority of city and suburban folk, 99/100 trips are not an issue.

I've driven (and overall enjoyed) a Nissan LEAF (pure EV) for the last 6.5 years. It's true that 99/100 of trips are not an issue, because many trips are short. Back/forth to work, back/forth to lunch, back/forth to sports, back/forth to the post office or grocery store.

Those quickly add up the 99% of trips (as measured by getting into the car and going somewhere). Those 1% of trips really impact your overall satisfaction with the car, though. I don't remember all the times the car effortlessly and nearly silently took me to work, but I do remember when I couldn't go to visit a friend or play in a softball tournament because my wife needed to use the ICE car for something and the LEAF couldn't do the trip. Or where we had to carefully plan who was going to take which kid to which activity and who was going to take the dog to her chemo appointment and in which car. If you "plan it wrong" in an ICE or hybrid, you lose 10 minutes. If you "plan it wrong" in a BEV, you lose an hour minimum (and more in a LEAF; mine has been DC fast charged twice since new, once before delivery and only once have I found and used a CHAdeMO in the wild).

I liked the LEAF (as the person who maintains our cars, I absolutely treasure it), but I suspect my next car will not be a pure electric. Teslas are more money than I choose to spend on a car. (Taycan is way more.) I'll probably end up with a 10-year old ICE car that will do everything I need for 20% of the purchase price, 30% of the insurance, and 150% of the marginal cost per mile, which is fine as we drive each car only about 3-5K/yr.

Re: Designing better batteries for electric vehicles

#28

Post by baybal2 »

csours wrote: post #24
baybal2 wrote: post #6

Note, the mass of an anode is at most 15% of mass of the modern battery cell. All "metallic" lithium cells still need some mechanical structure to hold lithium. So, at most you will get a half of the mass of graphite, given that graphite is already a quite lightweight material. For the cost, the second most expensive part in the cell after the cathode is the separator. Close to a third of cell's cost can be the separ…

From where do the Korean battery manufacturers source their separators?

I have no idea honestly. One may think they may be trying to avoid Japanese suppliers, but who knows. The entirety of Korean semi-industry sits on Japanese consumables for example. Times change.

Re: Designing better batteries for electric vehicles

#29

Post by gameswithgo »

sokoloff wrote: post #27
h4vot wrote: post #14

Earlier quoted context omitted.

Husband got a Jag i-Pace a few months ago. 400 km range. Haven't even bothered to get the fast charging equipment installed yet at home just give it 240 volts at night. Its never been under 50%. I think for the vast majority of city and suburban folk, 99/100 trips are not an issue.

I've driven (and overall enjoyed) a Nissan LEAF (pure EV) for the last 6.5 years. It's true that 99/100 of trips are not an issue, because many trips are short. Back/forth to work, back/forth to lunch, back/forth to sports, back/forth to the post office or grocery store. Those quickly add up the 99% of trips (as measured by getting into the car and going somewhere). Those 1% of trips really impact your overall satisf…

You might be able to get a used Tesla by then. Shops are proliferating that can repair battery packs for way less than replacement which offsets a lot of the risk.

Re: Designing better batteries for electric vehicles

#30

Post by gameswithgo »

csours wrote: post #26

Are such solid state batteries suitable for cell phones and laptops, power tools (drills, saws) etc? Are there conflicting engineering goals for batteries of small consumer appliances and vehicles?

Probably only a question of cost and fire risk. A solid state would be better for a phone, but the cost/weight/safety trade off might not be worth it there, by the time it is in a car (if it ever gets there)

Notable that electric car players are still innovating on non solid state, so I guess solid state isn't imminent.

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