The usual caveats are things like "we can't build a car-sized one" or "we can't manufacture it cost-effectively" or "we thought we could improve it a lot but couldn't".
New breakthrough every month! Shame that almost all of them don't pan out.
The article says their battery keeps 91% of initial capacity after 1,700 cycles at a rate of 2C, or 74% after 1,000 cycles at 5C, which sounds pretty reasonable given charge/discharge rates would likely be a lot lower than that in practice.
I do wonder what issues come from storing multiples of the same amount of energy in the same space, but I'm willing to wait and see. Anyways, beyond 400 miles or so, there's not so much value in longer range passenger EVs (obviously semi trucks for freight are a different use case). The real win if they can demonstrate this real-world will be the reduced weight or cost per mile of range.
> I do wonder what issues come from storing multiples of the same amount of energy in the same space
If it makes you feel any better, gasoline stores 12,888.9 Wh/kg according to Wikipedia. So if you're worried energy density in car crashes, it's still much lower than the status quo.
The issue is that batteries can just short out internally and dump the stored energy into themselves as heat, all within a few seconds. Gasoline can't really do that, and needs an (external) oxidizer to release those 12kWh/kg.
Well, OK, but gasoline's energy storage includes its own mass, which is combusted to release the energy, whereas the mass of a battery is basically constant despite charging and discharging, so it's not directly comparable in the sense you describe.
However, now that you bring it up, given that the most efficient ICE cars are about 25% efficent, you get at most 3200Wh of actual usable propulsive energy from the kg of gasoline. If the claims pan out, that is within shooting distance of these Li-S batteries' specific energy, even when accounting for EVs' 60-80% battery-to-wheel efficiency.
The status quo is Lithium-ion batteries which have certainly been known to spontaneously combust or catch on fire. Gasoline, by contrast, is remarkably stable.
I've also never given much thought to parking my gasoline fueled vehicles inside my garage. When ICE cars do spontaneously ignite, it's never because of the gasoline.
I do sometimes think about how prudent it is to park my Tesla underneath my kids' bedrooms every night while it starts charging unattended after everyone is asleep. I'm glad to have a smoke alarm in the garage.
I am glad you have a smoke alarm in the garage I am now thinking how mine died in the garage and I sleep right above it. If it was me in your position I would make sure I used a linked fire alarm system where if one goes off they all go off. It will buy you precious extra seconds getting your kids out as fires can spread incredibly fast.
Yep, ours are all wired together. Sometimes when I am a little over-enthusiastic searing a steak, I think they can probably hear the ruckus a quarter mile away when every single alarm goes off at once. Makes me feel somewhat secure that I'll be woken up if there is ever an actual fire.
ICE engine fires mostly happen on old, unmaintained cars. Very few almost new $60k++ ICE cars spontaneously combust because of the fuel (a short circuit in the dashboard would cause a fire in any type of car). When they do they're relatively easy to put out. And it's a bit easier to spot a potential fire hazard in advance, providing you do the regular checks.
On the other hand a battery fire is about the worst kind of fire a regular person might encounter in day to day life. It's a nightmare even for firefighters. They are very hard to put out and don't want to stay out. There's also no easy way to inspect the battery for such fire-causing potential defects. A single defective cell can cause a thermal runaway event.
It's the unpredictability that makes battery fires more dangerous. At this point we have no feasible preventive measures, no yearly service visits, no visual check for leaks, nothing.
> Anyways, beyond 400 miles or so, there's not so much value in longer range passenger EVs (obviously semi trucks for freight are a different use case).
If you could have a much longer range, then you could put up with more hassle to charge, which in turn could make some technologies feasible that would not be with lesser range.
For an extreme example, if you can go long enough on one charge then it might be feasible to use a non-rechargeable battery and replace it when it is out.
Believe it or not that has actually been considered. There is a company or two working on EVs using aluminum air batteries. Those are among the highest energy density available in batteries, comparable to gasoline. They are currently used in some military applications for aircraft and submarines.
The claim I've seen is that you could do an EV with these that would have a 2000 km range using less battery weight than current lithium ion EVs use. As I said, these aren't rechargeable, so every ~1800 km you'd have to take it in for a battery swap.
Presumably they would design these cars so that this would be a fairly easy operation. The dead battery would be sent back to the manufacturer for recycling. As the battery is used, the aluminum anodes become oxidized. The manufacturer can replace the anodes, and can extract the aluminum from the aluminum oxide and use that for making new anodes.
There's lots of advantages of having more potential range. You can pull a trailer and still go a significant distance. How about driving in alaska? Sure, most people drive less than 30 or 40 miles a day. Having an ev has taught me you can never have too much range, at least in today's world.
I'm curious about the real range requirements for EV freight trucks. At least in Europe, there's very strong regulations for mandatory rest periods for freight truck drivers. It seems to me you would basically design the system including the infrastructure so the trucks end up on a charger during those rest periods, and therefore don't need a very long range battery unless it improves the economics.
I'm sure smarter and knowledgable people have done the numbers on this; I should go find a good source ...
Until chargers are as common as gas stations and charging takes five minutes, I'd see a lot of value in a battery that could get me through a road trip without ever needing to recharge.
You’re never more than about 100 miles from a Tesla Supercharger station in the US, and while charge times are roughly 20-30 minutes, it hasn’t been an issue for the ~20k miles we’ve driven traveling the US.
Sure, it’s a bit longer than a 5 minute fill up, but between bathroom breaks, food, coffee, it’s not that much longer and we no longer have gas station trips when around town (charging our Teslas at home). Trade offs. Seems like the amount of folks who are waiting for 400 mile range EVs is exceedingly small.
You get used to it, but it is fair to call it a significant time cost. When we take the Tesla, we stop halfway to grandma's house for 20-30 minutes, then we stop again on the way back. Sure, it's a convenient break for the kids to go pee, but it's only a 2.5 hour trip each way and in our F150 we'd do the whole thing without any fuel or pee stops and it'd be fine. So it costs a solid hour, or 20% more time.
400 miles isn't that far. It's approximately the distance from Minneapolis, MN to Milwaukee, WI, which is a trip that I've done nonstop. It takes around 5.5 hours, which isn't too bad. Start around noon and arrive just a little before dinner.
Minneapolis to Chicago is a bit longer (a little over 400 miles), and takes about 6 hours. For that I'd probably need to stop somewhere to eat.
Assuming you pee at the origin and the destination, and it's freeway driving, that's two rounds of three hours between the bathroom. As long as the weather is nice, and you don't overhydrate, that doesn't seem unreasonable.
