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Solid-State Battery Has 2x the Energy–and No Anode

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Re: Solid-State Battery Has 2x the Energy–and No Anode

#141

Post by feifan »

subarctic wrote: post #136
phkahler wrote: post #127

Earlier quoted context omitted.

Actually, energy storage by weight is not as big a deal for electric cars. Regenerative braking can recover most of a vehicles kinetic energy, which is where the weight dependent energy goes. This is why several hybrids get better fuel economy in city driving than highway, the biggest losses are due to aero which increases nonlinearly with speed. Otherwise yes, it's important to find something better without sacrific…

>Regenerative braking can recover most of a vehicles kinetic energy I used to think that was the case, but then i think i read somewhere that it only recovers 20% of the kinetic energy. Can't find it anymore though

I've seen data showing ~70% recovery on a Model 3, but I also can't find the source :/

Re: Solid-State Battery Has 2x the Energy–and No Anode

#142

Post by hutzlibu »

subarctic wrote: post #136
phkahler wrote: post #127

Earlier quoted context omitted.

Actually, energy storage by weight is not as big a deal for electric cars. Regenerative braking can recover most of a vehicles kinetic energy, which is where the weight dependent energy goes. This is why several hybrids get better fuel economy in city driving than highway, the biggest losses are due to aero which increases nonlinearly with speed. Otherwise yes, it's important to find something better without sacrific…

>Regenerative braking can recover most of a vehicles kinetic energy I used to think that was the case, but then i think i read somewhere that it only recovers 20% of the kinetic energy. Can't find it anymore though

It is basic physic.

There is all the time friction of air and the road. You can never recover that.

And in rare cases where you actually can recover energy, at non emergency slowing down, it is probably indeed in that ballpark, wich is something(especially in city with stop and go), but not very high or much. With very high tech, you can increase that number a bit, but not worth the effort. Electric cars need good batteries and every improvement there is good.

Re: Solid-State Battery Has 2x the Energy–and No Anode

#143

Post by mikeyouse »

subarctic wrote: post #136
phkahler wrote: post #127

Earlier quoted context omitted.

Actually, energy storage by weight is not as big a deal for electric cars. Regenerative braking can recover most of a vehicles kinetic energy, which is where the weight dependent energy goes. This is why several hybrids get better fuel economy in city driving than highway, the biggest losses are due to aero which increases nonlinearly with speed. Otherwise yes, it's important to find something better without sacrific…

>Regenerative braking can recover most of a vehicles kinetic energy I used to think that was the case, but then i think i read somewhere that it only recovers 20% of the kinetic energy. Can't find it anymore though

Like OP mentioned, the efficiency of recovery varies by speed but is generally in the 65%-80% range for total round-trip (the system captures ~80% of the kinetic energy but with round-trip losses, you only get ~80% of that energy to propel the car).

Maybe you're thinking of the total range boost provided by regen braking? That's often shown to be roughly 20% via studies;

https://sci-hub.se/10.1109/vppc.2011.6043109

> Simulations show that the energy reduction of the vehicles under test can be more than 20% by applying regenerative braking.

It's an older study, but they show the regen efficiency at 60% for the EcoTruck and 70% for the bus.

Re: Solid-State Battery Has 2x the Energy–and No Anode

#144

Post by PragmaticPulp »

phkahler wrote: post #127
mabbo wrote: post #63

Lithium ion batteries set the standard because they have an acceptable level of all the key metrics: energy storage by weight; energy storage by volume; discharge rate; charging rate; production costs. Every single one of these big breakthrough announcements touts how great this new tech is- in just one or two particular metrics. The problem is that Li-Ion batteries are just barely acceptable in all of those metrics.…

Actually, energy storage by weight is not as big a deal for electric cars. Regenerative braking can recover most of a vehicles kinetic energy, which is where the weight dependent energy goes. This is why several hybrids get better fuel economy in city driving than highway, the biggest losses are due to aero which increases nonlinearly with speed. Otherwise yes, it's important to find something better without sacrific…

Heavier cars are more dangerous in collisions.

The extra weight of a big battery requires a bigger frame to carry it, bigger suspension, wider tires, and so on.

I’m not really happy that some of these monster EVs are approaching 10,000lbs with fast 0-60 times. It’s like a kinetic missile that can reach a momentum capable of obliterating your average 3000lb compact car in under 5 seconds.

Re: Solid-State Battery Has 2x the Energy–and No Anode

#145

Post by AlotOfReading »

newZWhoDis wrote: post #137
jackmott42 wrote: post #41

Earlier quoted context omitted.

EVs are already very heavy, and when the model 3 switched to LFP it got even heavier. This mass has lots of subtle consequences that aren't always appreciated. Like accelerated tire wear (which Tesla owners notice after they buy) and increased particulate pollution from that, increased road wear, increased danger to pedestrians and cyclists, etc. So, I'm less excited about LFP. There are a number of ideas in the work…

> increased danger to pedestrians and cyclists, etc. Why do seemingly so people here understand clipping functions? The lethality of a pedestrian-vehicle collision with a 4,000lb vehicle at 60MPH and a 400,000lb vehicle at 60MPH are both 1 In practical terms, the additional weight of an EV has zero effect on pedestrian collision lethality, whereas something like bumper design would.

I'm not sure why clipping functions are relevant, because the probability of death isn't 100% even for semis hitting pedestrians at highway speeds. It's actually more like 80-90%. There's still quite a bit of long tail for higher speeds beyond that as well. SUVs and other "heavy" consumer vehicles are somewhere in the 75% range at comparable speeds, while sedans are down around 65% mortality. Feel free to find your own numbers, but I'm using [1]. Vehicle weight and size clearly have a significant effect on mortality even at high speeds.

However, not all collisions are at highway speed. Most collisions are at relatively low speed, where weight is an even more significant factor in the energy involved. There are tradeoffs you can make between weight contributed by safety equipment (e.g. bumpers), but to a large extent those tradeoffs are mandated by regulations rather than consumers or OEM engineers.

[1] https://www.moneygeek.com/insurance/auto/analysis/pedestrian... [2] https://www.nber.org/digest/nov11/vehicle-weight-and-automot...

Re: Solid-State Battery Has 2x the Energy–and No Anode

#146

Post by [deleted] »

phkahler wrote: post #127
mabbo wrote: post #63

Lithium ion batteries set the standard because they have an acceptable level of all the key metrics: energy storage by weight; energy storage by volume; discharge rate; charging rate; production costs. Every single one of these big breakthrough announcements touts how great this new tech is- in just one or two particular metrics. The problem is that Li-Ion batteries are just barely acceptable in all of those metrics.…

Actually, energy storage by weight is not as big a deal for electric cars. Regenerative braking can recover most of a vehicles kinetic energy, which is where the weight dependent energy goes. This is why several hybrids get better fuel economy in city driving than highway, the biggest losses are due to aero which increases nonlinearly with speed. Otherwise yes, it's important to find something better without sacrific…

[deleted]

Re: Solid-State Battery Has 2x the Energy–and No Anode

#147

Post by DennisP »

tromp wrote: post #116
DennisP wrote: post #114

Earlier quoted context omitted.

Here are the specs on the Amprius silicon-anode battery, currently shipping in low volume: https://amprius.com/products/ That's better on all the metrics you listed except cost, which it doesn't mention. Whatever their current cost is, it should drop significantly once they complete their factory in 2025. https://amprius.com/facility/ Most of the battery is standard lithium-ion, the anode is a drop-in replacement.

It mentions lasting for 200-1200 cycles, which (besides a suspiciously large range compared to Li-ion's 500-1000 cycles) is not better on all mentioned metrics.

The above comment didn't mention cycles but I should have said "similar or better." Cycles are comparable, seems likely it's just more sensitive to poor management. With about twice the capacity, fewer cycles are more tolerable anyway.

In any case, this looks like a very practical battery with serious advantages over lithium-ion.

Re: Solid-State Battery Has 2x the Energy–and No Anode

#148

Post by lazide »

PragmaticPulp wrote: post #144
phkahler wrote: post #127

Earlier quoted context omitted.

Actually, energy storage by weight is not as big a deal for electric cars. Regenerative braking can recover most of a vehicles kinetic energy, which is where the weight dependent energy goes. This is why several hybrids get better fuel economy in city driving than highway, the biggest losses are due to aero which increases nonlinearly with speed. Otherwise yes, it's important to find something better without sacrific…

Heavier cars are more dangerous in collisions. The extra weight of a big battery requires a bigger frame to carry it, bigger suspension, wider tires, and so on. I’m not really happy that some of these monster EVs are approaching 10,000lbs with fast 0-60 times. It’s like a kinetic missile that can reach a momentum capable of obliterating your average 3000lb compact car in under 5 seconds.

That is pretty much the definition of moving the goal posts?

Re: Solid-State Battery Has 2x the Energy–and No Anode

#149

Post by entropicdrifter »

londons_explore wrote: post #106
raddan wrote: post #92

Earlier quoted context omitted.

I’m sure this is not what the poster meant, but in fact most EVs and hybrids use multiple battery technologies in parallel. For example, a Chevy Bolt has a lithium ion battery to power the drivetrain and a conventional lead-acid battery for the accessories. My old Prius had a NiMH battery for the drivetrain and a lead-acid battery for accessories.

A lead acid battery is just a holdover from the way every car used to have one for the accessories, and unless you want to redesign all the accessories, it's easier to have a 12v-14v circuit just for that. And before you say "oh, but they could just use a voltage converter from the high voltage battery", they need to consider that some accessories use hundreds of amps briefly (eg. the power steering - that makes for…

My Hyundai Ioniq hybrid has a 12v section of the Li-ion battery that can be charged off of the hybrid battery while the car is off with the press of a button so that the car never needs to be jump-started unless the entire hybrid battery is dead.

Re: Solid-State Battery Has 2x the Energy–and No Anode

#150

Post by panick21_ »

DennisP wrote: post #114
mabbo wrote: post #63

Lithium ion batteries set the standard because they have an acceptable level of all the key metrics: energy storage by weight; energy storage by volume; discharge rate; charging rate; production costs. Every single one of these big breakthrough announcements touts how great this new tech is- in just one or two particular metrics. The problem is that Li-Ion batteries are just barely acceptable in all of those metrics.…

Here are the specs on the Amprius silicon-anode battery, currently shipping in low volume: https://amprius.com/products/ That's better on all the metrics you listed except cost, which it doesn't mention. Whatever their current cost is, it should drop significantly once they complete their factory in 2025. https://amprius.com/facility/ Most of the battery is standard lithium-ion, the anode is a drop-in replacement.

Amprius technology will not magically drop in price as much as people think. Some manufacturing methods don't just scale and become cheap.

Their large facility planned is still tiny in terms of battery factories.

This will remain an expensive niche product.

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