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Comment by MisterPea | Hacker News Reader

Wait what?? What's the catch, 1200wh/kg is insane.

Putting the same weight of this into a Tesla Model Y would easily give over 1200 miles of range

The catch is that this is a tiny lab prototype, where the energy density is projected and I could not find it in the paper that the cycling was in fact tested for 1000 times and even though the starting materials are cheap the article is very light on details about mass manufacturing larger cells. I don't want to take away from the research and think it's super cool and hope it scales well to mass production but it's usually a long road from lab prototype to Tesla level production facilities.

> I could not find it in the paper that the cycling was in fact tested for 1000 times

The team established that this shortcoming is not the case for their new battery design by building and operating a test cell for 1000 cycles, demonstrating its stability over repeated charge and discharge.

I read that in the article but in the paper I only found a mention of tests for 200 cycles.

> long road

But how long? Longer than 300 miles?

Almost all inventions you hear about in the lab phase like this NEVER make it to production.

But sometimes they do.

Most of these inventions don't live up to their initial hype, but some do find a niche (for example cell chemistry optimized for large temperature ranges, optimized for certain safety features, longevity over charge density etc.), and ideas from some of them find their way into mainstream batteries after a decade or two.

It basically never happens that a new cell chemistry becomes the market leader in all areas, but all in all, batteries to get better and cheaper at a remarkable rate.

Argonne got NMC to market. I wouldn't discount Argonne.

If interested in battery technology and Argonne I'd recommend this book: "The Powerhouse: America, China, and the Great Battery War" [0]

[0] https://www.amazon.com/Powerhouse-America-China-Great-Batter...

Concur interesting read!

For anyone else curious, NMC is probably https://en.wikipedia.org/wiki/Lithium_nickel_manganese_cobal...

> Lithium nickel manganese cobalt oxides (abbreviated Li-NMC, LNMC, or NMC) are mixed metal oxides of lithium, nickel, manganese and cobalt. They have the general formula LiNixMnyCozO2. ... NMCs are among the most important storage materials for lithium ions in lithium ion batteries. They are used on the positive side, which acts as the cathode during discharge.

"80% of the time, it fails, every time..."

To quote Terry Pratchett:

99 out of every 100 ideas they come up with are complete rubbish, but the 100th tends to be an absolute humdinger.

Take a commonly held opinion. Something that all the smart people hold to be true.

Frame it wisely and wittily enough for fast food. Feed it back to those smart people.

That's Terry.

Take someone who's achieved something. Someone widely admired.

Shit on them. Imply there was nothing impressive about what they did and it wasn't worth doing.

That's HN.

> That's HN

As opposed to the miracle of selection elsewhere. /S

The stats are not crazy for an air battery.

But the catch is two-fold. First, are they weighing the battery before or after discharging? Oxidizing will change the weight significantly. The most honest result would be the average weight during the cycle.

The other catch with these air batteries is usually the purity requirements on the intake. I recall reading about earlier experiments that could not tolerate pollen, dust, and smog, and required an energy intensive purification step (maybe involving cryogenics) that was a nontrivial power draw.

Those caveats aside, a back of the envelope estimate for the energy density would be something like 600-700 Wh/kg.

The other issue is that metal-air batteries go by another name: fuel cells. You are power-gated by how much oxygen you can deliver to the battery. As a result, metal-air batteries/fuel cells are either very slow to discharge, or have big air pumps to have decent performance.

And of course, they will release oxygen if you try to charge them, which implies a way of rapidly expelling air when charging up quickly. Many past attempts avoid this problem by "mechanically" charge up the battery, meaning literally swapping out the spent chemicals with new ones. This of course require an auxiliary battery if you want regenerative braking or the ability to electrically charge.

And of course, the real catch is that we've already invented the metal-air battery in a practical way: hydrogen fuel cells. The big advantage with them is that mechanically recharging is very straightforward compared to other mechanisms. All other attempts are basically reinventing the wheel or have a very specific niche in mind.

A problem with fuel cells is that if they're acid, they need expensive platinum group element electrodes. If they're alkaline, they can use nickel, but then they need to have the CO2 scrubbed from the air or they clog up with carbonate.

But there's something to be said for a fuel that's solid under ambient conditions rather than being literally the least-dense substance on Earth.

Methanol fuel cells exist too.

> a back of the envelope estimate for the energy density would be something like 600-700 Wh/kg.

https://www.google.com/search?q=current+tesla+battery+energy... says Tesla batteries are currently in the range of 270-290Wh/kg

Is that accurate to you?

As in this is roughly at least twice as good as current technology? Seems too good to be true. When can we expect to see it hit consumer cars? 5 years? 10 years?

Except tesla is expecting and has been achieving 10% density increases in the last few years. Do this for 8 years, and you get double, same as the new battery tech that's gonna take 10 years.

1st gen: 276 Wh/kg (2022)

2nd gen: 305 Wh/kg (2023)

3rd gen: 333 Wh/kg (2024)[1]

Here is a cool article on all the tech that is scheduled or went into these new 4680 batteries and getting the energy density up well past 300.

https://cleantechnica.com/2020/09/22/everything-you-need-to-...

[1]https://insideevs.com/news/598656/tesla-4680-battery-cell-sp...

Your info is out of date. The 4680 actually ended up being 244Wh/kg[1], which is lower than the Panasonic 2170 at 269 Wh/kg that they were already using.

[1] https://www.youtube.com/watch?v=4XOHetABrag

Still, Tesla with 4860 is 9kg lighter than Tesla with 2170.

https://insideevs.com/news/600297/tesla-model-y-4680-is-just...

I assumed Tesla was at 300, which is pretty close. This might not be the tech for consumer cars though, but one thing I have seen is the enormous proliferation of applications for Li batteries as the costs have come down, and these will certainly find an application. That would be my bet.

Maybe one catch is that the weight of the discharged battery is much higher than the weight of the fully charged one. So, as you travel, the battery becomes heavier and heavier

> This new solid enables chemical reactions that produce lithium oxide (Li2O) on discharge.

Lithium has an atomic mass of 7 and Oxygen of 16. The reaction starts with only Lithium (2 atoms = 14 mass) and ends with Li2O, with a mass of 30.

Most of the weight of the battery isn’t lithium, so the effect isn’t as bad as you might think.

you could start out 4 times lighter than a modern battery pack and end up only 2 times lighter when discharged..

that would be fine!

> Maybe one catch is that the weight of the discharged battery is much higher than the weight of the fully charged one.

That would add an interesting dynamic during a race!

This could make things interesting for aircraft, where currently they get considerably lighter as they reach the end of their flight.

Probably the same catch as any major battery news: going from lab to actual real-life production is a long journey, and it's as yet unclear if the manufacture can be scaled up and if it can work in real-life applications.

parameters that are important:

1. how fast can you charge it

2. how much power can it output?

3. how long does it last time wise, not just cycle wise

4. how much does it cost

5. how much space does it take up

6. what temperature ranges can it handle?

7. can it handle vibrations

just a few

doest is suffer from thermal runaway etc.

All these parameters do is help determine its best possible use-case for product and if it something to compete against incumbents or open up other market possibilities.

> thermal runaway etc

From the article: "The main new component in this lithium-air battery is a solid electrolyte instead of the usual liquid variety. Batteries with solid electrolytes are not subject to the safety issue with the liquid electrolytes used in lithium-ion and other battery types, which can overheat and catch fire."

Volumetric density matters too.

Very long cars are going to make a comeback. Parking lots will never be the same again! Wonder how well the batteries tolerate deformation and if they could be molded into crumble zones.

> Very long cars are going to make a comeback.

Not in Europe, a lot of US cars already wouldn't fit in EU parking spots (most are 5mx2.3m)

Parking spaces in US cities can get smaller the closer you get to the central business district. Eventually they're marked as 'Compact' so hopefully only those in compact cars will attempt to use them. If Lithium-Air batteries enabled widespread adoption of EVs over ICE vehicles, but at the cost of requiring longer vehicles, would enlarging parking spaces be an acceptable cost?

People driving oversized cars from US in EU have no qualms about taking 2 parking spots.

They might park over the lines of outdoor parking slots but they won't fit into single car garages.

For consumer electronics, absolutely. Not so much for cars. A Tesla battery pack is a big sheet just 3" thick. You could double that easily without significant effect on the layout or design of the body.

A friend of mine works at a major established car manufacturer and has been working on solid state electric batteries for awhile, and thinks it is the future (he recommends ignoring current EVs in favor of plug in hybrids until these batteries come out). He thinks when these batteries are ready to be put in cars they'll end up somewhere around 2-3x improvement in range, so slightly less than the 1200 miles but reasonably close.

1000 cycles is about three years of use. I personally charge my EV every night, it's better to form a habit of plugging it in every night than to forget to check it and not have enough energy in the morning.

no, 1000 cycles doesn't mean 1000 charging events will end it. 1000 cycles from 100 to 0% will end it, and if its like current batteries, you get more than say, 10X as many cycles when you only use 10% of the battery per cycle

Once charging/discharge times come down, trickery can be used to turn 1000 into 10,000 cycles easily. If you can charge fast, you can isolate cells alto charge/discharge them individually, only jumping to other cells once the first is full. Essentially, it's wear leveling of batteries as done with flash memory. At the moment individual cells cannot charge/discharge fast enough to fully enable this.

In addition to what you said, after the rated cycles most Lithium batteries still work and can still hold 70~80% of their original capacity.

Discharging/Charging 10% 10 times is 1 cycle. https://www.apple.com/batteries/why-lithium-ion/

Just checked a relatively new iPhone that is 132 days old. I charge it nightly, even though it hardly goes below 50%. In fact, battery stats for last 10 says that it used on average 40% battery per day, and it is pretty typical usage for me. It has 111 charging cycles.

Something doesn't add up.

The Model Y battery is 771 kg. At 1200 Wh/kg, we're looking at 925 kWh. That's 12 times the current battery (76 kWh). So range would be ~500 km x 12 = 6,000 km.

1200 miles, but takes 3 days to fully charge.

Let's go metric with 2000 km. The 2021 Kona EV has a range of about 500 km. The level 2 charger at my house takes 9 hours to recharge from empty (i.e., overnight). That's 1.5 days to fully charge a battery offering a 2000 km range, in theory, which is half your estimate. A DC fast charger can recharge 400 km in 50 minutes (80% capacity), equivalent to 4 hours for 2000 km. Meaning those batteries will probably take closer to 5 hours to fully recharge when using the fastest chargers available today.

The article makes no mention of charging time, which would lead me to believe it's barely identical and most likely worse than current rates.

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