Amprius High-Density Batteries | Hacker News Reader

Amprius High-Density Batteries

eetimes.com

43 pointsJoachimS25 comments

I've been following news about this company for 10 years now.

What's remarkable about them is that they had a sufficient for large-scale deployments, roll-to-roll process already developed back in 2016, and that was after their short partnership with a Chinese phone maker, where they delivered a 5000mAh battery.

They might not beat their competition to market in terms of scale, but they definitely have an edge in terms of experience manufacturing their product.

Exiting times ahead of us. I hope this makes its way to consumer devices like e-bikes eventually. Or cars for that matter.

When I applied to undergrad in 2007, I kicked myself for not sending in an application to Stanford (though I probably wouldn't have gotten in anyway) when I learned about the Cui group's silicon nanowire battery project shortly after the application window had closed. It's intriguing to see how long it takes to get these developments from lab to factory.

Here's the 2008 version of Wikipedia's "List of emerging technologies" showing the nanowire battery way back then — where I first heard about it:

http://en.wikipedia.org/w/index.php?title=List_of_emerging_t...

I wonder how many people from that batch are still in the company?

I remember the BluBoo X550 with a whopping 5300mAh battery and thinking that this is it - this is going be the product that will provide enough financing and investment for them to kick-off large scale production.

Unfortunately it was a flop because the device was so badly optimized that battery life wasn't as spectacular one would suspect going by capacity alone.

Good thing they found more profitable markets to tap into.

I'd say much of the work to improve silicon nanowire batteries et al. happened 2010 onward. I think pre-2010, it was mostly strong proof of concept with okay-cycling performance.

source: I was in the Cui group.

I still feel like e-bike makers are missing a mark, a lighter bike with like 30-40km range for a battery could be cheaper and will fulfill most people's needs.

Two recent Munro Live episodes:

Nobody Has Anything Like This: Amprius Factory Tour [2023/05/08] https://www.youtube.com/watch?v=v_Hd4HfH1ss

Amprius Creates a 500Wh/kg Battery [2023/03/03] https://www.youtube.com/watch?v=YtZkohZRE_s

TLDR, Sandy observes test of fast charge. IIRC, Something like 80% in 6 min? Which I understand is big improvement.

Meaning, Amprius cells are both more power dense and quicker to recharge (at least to 80%).

How many charge cycles can they take? In many cases improving the energy density requires a finer more precise process resulting in a more fragile short lived battery.

So you don't have to dig: "Amprius’ commercially available batteries deliver up to 500 Wh/kg and 1,150 Wh/L"

Also so you don't have to dig, a Tesla's battery density is apparently 200 wh/kg.

That's pack-level density. Cell-level is ~280Wh/kg.

Reportedly packs of comparable size from Amprius are 70% more dense, so 340Wh/kg. Still a very good number, which could lay to rest concerns about curb weight and range of EVs.

Does that mean it requires a heavier pack than lithium ion, so more risk of damage/fire in each cell?

The rule of thumb I use for my Tesla is one mile of range costs one kg.

I asked GPT-4 to calculate the energy density required for a Ford F-150 Lightning to weigh the same as its gas counterpart. Seems about right to me.

> The Ford F-150 gas version has a gross weight of 6,470 lbs (2,934 kg)【14†source】, while the Ford F-150 Lightning EV has a gross weight of 8,250 lbs (3,742 kg)【25†source】. This means the EV version is 1,780 lbs (807 kg) heavier than the gas version.

To calculate the required pack density and cell density for the EV to weigh the same as a combustion vehicle, we need to know the weight of the battery pack in the EV. Unfortunately, that information is not directly available. However, we can make some educated estimates based on the battery's energy capacity and typical energy density values for EV batteries.

The battery capacity of the Ford F-150 Lightning EV is 98 kWh【21†source】. As of 2021, the energy density of commercial lithium-ion batteries (the type typically used in EVs) is approximately 250 Wh/kg. Assuming this value, the weight of the battery in the EV would be approximately:

98,000 Wh / 250 Wh/kg = 392 kg

However, this estimate is for the cells alone and does not account for the additional weight of the battery pack structure, cooling systems, and other components, which can add significant weight. For example, for the Tesla Model S, the battery pack weight is about 1.4 times the cell weight. If we assume a similar ratio for the Ford F-150 Lightning, the total battery pack weight would be approximately:

392 kg * 1.4 = 549 kg

Given this estimate, the battery pack represents a significant portion of the additional weight in the Ford F-150 Lightning EV compared to the gas version.

To make the EV weigh the same as the gas version, the battery pack would need to weigh 807 kg - 549 kg = 258 kg less. This could be achieved by improving the energy density of the battery cells, reducing the weight of the battery pack structure and other components, or some combination of the two.

If we assume that the weight of the battery pack structure and other components cannot be significantly reduced, then the required improvement in cell energy density would be:

Current cell weight: 392 kg Required cell weight: 392 kg - 258 kg = 134 kg Required cell energy density: 98,000 Wh / 134 kg = 731 Wh/kg

This would be nearly a three-fold increase over the assumed current energy density of 250 Wh/kg.

Please note that these are rough estimates and the actual values may vary based on the specific design and construction of the vehicle and battery pack. Additionally, increasing the energy density of battery cells is a major area of research and development in the field of battery technology, and significant improvements may be possible in the future.

> 6,470 lbs (2,934 kg)【14†source】, while the Ford F-150 Lightning EV has a gross weight of 8,250 lbs (3,742 kg)【25†source】. This means the EV version is 1,780 lbs (807 kg)

It's weird to me that it can get 3742kg - 2934kg wrong.

It didn't, it did the subtraction in lbs and got the right answer, the off-by-one is due to rounding.

A natural fit for last week's ground effect seaplanes:

https://news.ycombinator.com/item?id=36051831

Exciting times for VTOL companies. They've been called various flavours of "scam" or "vapourware" a lot because of their energy demands, but ultimately they're all bets on the continued improvements of battery tech, which is a pretty safe bet. There's tens of billions of capital flowing into battery development every year (https://report.volta.foundation/annual-battery-report/public...), so if you have everything else nailed down and just need better batteries, you're in good shape.

The Moller Skycar [1] will finally have it's day!

1. https://en.m.wikipedia.org/wiki/Moller_M400_Skycar

My understanding is that even if you solve the actual plane + battery etc, the real rub is where do you take off and land? Most of the demand is going into/out of a city, and cities have very few places appropriate to land helicopters. Basically at the top of buildings that already have structural support, which are expensive and few.

_If_ we can make them generate a lot less noise and be a lot safer (both not that unrealistic), I would think more places to land them would rapidly pop up.

Also, but that’s in the really long term, if we could do air traffic control for millions of machines without creating congestion, I would expect city centers to sprawl out a lot. Why impress your clients with an office on the 50th floor of a skyscraper in Manhattan if you also can put it on a hillside overlooking some national forest, unreachable by car, but only 20 minutes flying away?

The rest of us plebs that are forced back to the office do not get a spot on the helicopter?

Helicopters are VTOLs. And all VTOL concepts have basically the same aerodynamic problems. So no, it is incredibly unlikely these problems can be solved easily.

Which is why VTOL concepts have stayed vaporware. People are simply trying to sell helicopters with a new name. It mirrors the endless attempts to build systems that work exactly like trains, but with a much sillier mechanism of operation. Both strategies are built on willful ignorance of what they're really trying to do, and are nearly guaranteed to fail.

If battery is the only problem, it can be solved by using gas now (except emissions). There are many reasons human riding eVTOL called scam.

>Amprius’ commercially available batteries

so where can I but one to verify claims? crickets ...

https://amprius.com/the-all-new-amprius-500-wh-kg-battery-pl...

Words buy/sell dont exist in that press release.

Condensed matter battery?

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