Developer of aluminum-ion battery claims it charges faster than lithium-ion | Hacker News Reader

Developer of aluminum-ion battery claims it charges faster than lithium-ion

motoring.com.au

54 pointselorant59 comments

I happened to read the same information but reported by another publisher [1]. In that article, it points out that the energy density is only 60% of a traditional lithium-ion cell, but that disadvantage is offset by not having to use much cooling device like the lithium-ion ones.

The same information is represented pretty differently in this article, leading people to believe the energy density is better:

"The new battery cells are claimed to deliver far more energy density than current lithium-ion batteries, without the cooling, heating or rare-earth problems they face."

Still, I think is an encouraging news and I really love, just not quite a fan of the way they present it.

[1] - https://newatlas.com/energy/gmg-graphene-aluminium-ion-batte...

[edited for grammar]

You could easily imagine an EV with a hybrid battery pack consisting of 2/3 Li-Ion and 1/3 Al-Ion. You pay very little in range for the combination compared to a Li_Ion pack, but you gain flexibility. You then discharge the Al-Ion part of the pack first, partly because it has better longevity across cycles, but mostly because this then lets you charge that empty third of the pack very quickly giving enough range for an extra hour or two of driving.

Delivering that much power seems pretty difficult to me. EVs already charge at dozens of kW. How high do you have to make the voltages to keep the cables a reasonable diameter when you want to charge in the Megawatt range?

If you assume that 500A is the largest cable that a user can handle[0], then 2kV per megawatt. If you don't mind actively cooling the part of the cable the user handles, then you could run at higher currents for the same cable size.

The biggest problem likely will be the much higher demand charges from the power company (they really don't like sudden large loads), so the charging station will likely need a large battery pack of its own.

[0]: You want injured/elderly people to be able to charge without assistance so cable weight/stiffness is a important design factor.

Sounds crappy but what if faster charging ends up being accomplished with more cords and more charging ports? Want double charging rate? Plug in two cords.

I can see this as something that is included in upgraded trims. Mid-level trim = two charging ports. Premium trim = 3! $$$

You could definitely increase the ampacity if each charging cord was only one wire. Perhaps that's the key to quick recharges?

Also gives you something to do, while you are waiting. By the time you plugged in the 5th wire, the first 4 charged you halfway :D

A "Megawatt Charging System" (MCS) is already in development for charging heavy commercial vehicles and aircraft. It's designed to scale up to 3000 A at 1500 V.

https://en.wikipedia.org/wiki/Megawatt_Charging_System

They're already working on deploying 350kW 500 amp charging stations. That's about 5 minutes to get 100 miles, and the cables are a bit awkward but not too bad. And 500kW 500 amp is easily accomplished on the same standards.

Also keep an eye on potential 2-3 megawatt plugs for trucks.

I've always thought it should go the other way.

Add a supercapacitor.

This would allow bursts of extreme power, along with stronger regenerative braking with full capture of energy.

I think the racetrack would be a great use case.

Last I looked, supercapacitors just aren't quite high up enough on the volume/energy curve.

Getting rid of a few batteries to make space for a few supercaps so you can regen quickly when emergency stopping sounds great, but then you realise it can only capture a tiny portion of the cars energy at 70 mph unless you replace nearly all the cars battery.

I wonder if the apparent contradiction can be explained by the difference between the energy density of a cell (i.e. a single instance) vs of a battery (i.e. a practical aggregation of a number of cells)? I don't know how much space the cooling etc. takes up in a practical lithium-ion battery.

In this case, energy density refers to the energy per unit mass, not volume. But your point still applies, for application in a vehicle you need to compare the mass of the complete battery systems, not just the cells in isolation.

As battery designs are getting better, the difference is getting smaller and smaller.

Turns out cooling systems can have very thin tubes with very thin walls.

That article was discussed a bit here:

Superfast-charging aluminum-ion batteries outpower lithium-ion - https://news.ycombinator.com/item?id=27205855 - May 2021 (8 comments)

Edit: False assumption of atomic radius lead me to make an invalid conclusion

On paper the top-level explanation of the technology makes sense by virtue of an Aluminum ion being able to transfer 3 electrons vs Lithium's single electron thereby achieving a faster discharge rate seems plausible. However when taking into account molecular weight it becomes a different story, at least as far as energy density is concerned. Lithium's molecular weight is 7 while Aluminum's is 27. So we'd be using 28.5% more mass to achieve the same energy density. And there is also the increased number of Aluminum's orbital shells to take into account so more volume would be require vs Lithium.

How much this can be offset by the apparent lack of need for a heating/cooling system for vehicle tier applications remains to be seen. I'm guardedly cautious but hopeful.

Aluminum has 3x the thermal conductivity of lithium and half the thermal expansion, so this could result in a larger space savings.

The weight is an issue but if we end up with less issues around dendrites etc, it might not matter? I imagine that larger cell sizes and lack of need for cooling might offset the perceived weight issues.

I'd also be very curious about the longevity of the battery as well vs lithium-ion.

I imagine for the automotive space (air running over the battery could be all it needs to cool) this could be huge, but maybe not so much for cellphones/aerospace!

> I imagine that larger cell sizes and lack of need for cooling might offset the perceived weight issues.

Have you ever looked at Tesla's vehicle cooling system visualizations?

It's not like by eliminating need for cooling in the battery you'd be able to omit the vehicle's cooling system. The coolant circulates through practically every active component of the vehicle, and regardless of battery requirements you'll still need sufficient thermal mass circulating to not overheat any of the other high-power components capable of producing a lot of heat like the motor and controller.

Though maybe there could be some reduction in coolant volume by treating the less thermally sensitive battery as more of a heat sink, by continuing to circulate coolant through it. Still, I don't imagine it'd be a huge weight savings, but may help stabilize temperatures.

That's a fair point but nevertheless what the article meant by lack of need for cooling is twofold.

The ability for the aluminum ion battery pack to function in a wider temperature range potentially does away with a heating system that is otherwise needed to help li-ion battery packs to function better (or even avoid early degradation) from a cold start.

The implied lack of a need for a cooling system for the battery means the battery can function as a thermal mass, as you alluded, and a lower rate of circulation and total mass of coolant is necessary. That's on top of a simplified channel system that runs only through the motors, alternator, electronics that lie next to heat generating parts, etc.

I just looked up the volume of aluminum vs lithium here: https://www.periodic-table.org/lithium-atomic-radius/

They have the same atomic radius of 121 pm. The length of bonds might change the calculation when you actually look at chemistry, but the increase in number of orbitals is not an issue.

Also, no battery uses 100% of their electrons for storage. Your calculation of using the number of electrons on the outer orbital vs the atomic mass is completely misguided. their claims don't say aluminum ion holds more energy per unit mass, but simply looking at the ions available per unit of molecular mass also doesn't tell you this.

You're correct - my assumption about atomic radius was off, which leads to an erroneous conclusion.

Perhaps someone can help me with a question. I read this and look for a elementary explanation of the operation of an aluminum-ion battery. Wikipedia yields this[1]:

    "Aluminium-ion batteries are a class of rechargeable battery in which aluminium ions provide energy by flowing from the positive electrode of the battery, the anode, to the negative electrode, the cathode. When recharging, aluminium ions return to the negative electrode, and can exchange three electrons per ion."

This description appears self contradictory. On one hand the battery "provides energy" when ions are "flowing from" the anode to the cathode. When recharging, the opposite of "providing energy," one should then expect to be told that the reverse happens; the ions would return to the anode. Yet the Wikipedia description tells us the opposite when recharging; "aluminium ions return to the negative electrode [cathode]."

Nowhere in this cycle, according to this description, are the ions returned to the anode. What am I missing?

[1] https://en.wikipedia.org/wiki/Aluminium-ion_battery

https://en.wikipedia.org/w/index.php?title=Aluminium-ion_bat...

They probably forgot to also change the second sentence.

The terms anode and cathode are reversed. Mnemonic device:

Anode - ants - bad - negative

Cathode - cats - good - positive

This is the opposite of what I understand: anode positive, cathode negative.

Google (and multiple other sources) confirm my understanding:

  an·ode /ˈanōd/ the positively charged electrode by which the electrons leave a device.
  cath·ode /ˈkaTHˌōd/ the negatively charged electrode by which electrons enter an electrical device.

It depends on whether you're talking about electron flow or conventional current, because they're opposite each other. The original mnemonic is incomplete because it doesn't specify to which it refers.

left hand side of the road, or right hand side of the road?

You've lost me.

Different domains have different conventions, regardless of what may be in a definitive reference.

obligatory xkcd https://xkcd.com/567/

They are talking about impregnating graphene with atoms of Aluminium and getting it in production by the end of the year. Yet I was under impression that we do not yet have a viable method for producing graphene on an industrial scale, did I miss something? Do we have such production capabilities or do the batteries in question require so little of it that the existing tech is enough?

We can produce graphene at scale but it's not big uniform layers but small randomly oriented pieces.

Big uniform layers are prohibitively expansive (and you have to provide your substrate to them)

Making particles of it is easy, making sheets is where it is still hard, so that's probably the bit that you're missing.

https://www.americanscientist.org/article/mass-producing-gra...

I assumed they would need sheets of it for batteries, but if it works for them with just particles all the better.

The term is impregmating in this context and process :)

Oh my, I never knew there was a different word for it, thank you!

> deliver 7000 Watts per kilogram in energy density.

Isn't "Watts per kilogram" a unit of power density?

Definitely hurts the credibility of the article.

Previous discussion: https://news.ycombinator.com/item?id=27153279

Seems to be the same content at a different site.

Ah. It is the same Australian battery "breakthrough" as last month.

Here's the company (Graphene Manufacturing Group) web site.[1]

They're publicly traded. Their actual products are some kind of energy saving paint, and a lubricant. 15-20 employees.

They claim they have coin cell prototypes now, and will have them for sale for testing purposes by the end of 2021.[2] If they actually deliver on that, they're for real.

[1] https://graphenemg.com/

[2] https://www.graphene-info.com/gmg-updates-graphene-aluminum-...

One of the side-interesting things about this article, is how Australia:

- massive net energy exporter

- ridiculous gas and coal infra + reserves

- ridiculous renewable potential

- Comparatively very little national debt and low borowing costs

... has prohibitively expensive energy prices.

To be fair, the reserves are largely a national security requirement given the risk of potential Chinese aggression (trade or otherwise).

Given its remoteness, Australia is quite vulnerable to blockade. While the country is of immense size, global shipping lanes are consolidated and pretty easy to block.

"Up to 70 times faster charging"...

Good luck building a charging network that allows charging a bunch of cars at ~1 MW each...

Tesla's apparently been building that for their semi's?

https://www.teslarati.com/tesla-semi-megacharger-charging-po...

In general it doesn't seem like an issue. Your local grid may or may not be able to directly load balance that much energy, but even if it can't, you judge add some storage batteries at your charging station to deal with the load balancing.

What is missing in all these new "breakthrough battery" articles: what are the drawbacks?

There were a lot of news in last decade about many breakthrough but they are still not on the market. So don't raise your hopes too high, time will show whether it's a breakthrough or just yet another small step forward.

I would say on the contrary. The breakthroughs do have visible results in the regular batteries. The Li-Ion of 2010 are nowhere near as reliable and powerful as the ones today. They're called the same, but they're very different.

https://cleantechnica.com/2020/02/19/bloombergnef-lithium-io...

I don't understand the electrochemistry that's supposed to be happening. Is it aluminum that is being oxidized and reduced? If so where do the electrons go when they return to the circuit?

The article doesn't mention the cathode, it just says the electrolyte is urea (CO(NH2)2) into which you can dissolve aluminum chloride (AlCl3) or, more precisely, an ionized variant like AlCl4- or Al2Cl7-. Changing between those two frees up some electrons. The cathode is probably lithium manganese dioxide, it changes between MnO2 and Li+ and LiMnO2. An aluminum-ion electrochemistry reaction is described here:

https://en.wikipedia.org/wiki/Aluminium-ion_battery#Electroc...

Note that it's oxidation as in oxidation/reduction, using chloride ions, not oxidation as in oxygen. Turning aluminum oxide into aluminum is done with acid/base reactions and high temperatures, I don't think it's achievable with rechargeable electrochemistry.

In a world of renewable energy, the battery technology that wins will not be based on charge time, density, or longevity but on cost and the ability to be efficiently recycled.

I think you're right. I could see a future where the charge station ends up just swapping batteries with you (kinda like the way propane tanks work in some places). Give them your used one and they give you a charged one. Adjust for power left on the trade-in and quick quality checks and validations on the units being swapped.

I've heard that whatever you do, it's hardly impossible to make better batteries because you can't fill matter with more electrons than with lithium.

I guess that would be the case if the battery was 100% lithium. But they are not (and cannot be) If I remember correctly the issue with increasing density in lithium batteries is their propensity to catch fire + explode (due to dendrites forming between lithium plates)

So a better battery tech might have a material that can store less electrons per m3 within the "active" material - but it can contain 30% more.

Really? If that is the limiting factor, then there is a lot of hope, because lithium is a tiny portion of a battery weight and volume, something like 1%. It means we could theoretically improve the batteries to hold say 30% lithium, for a 30x improvement in density!

You have to choose your trade offs.

Aluminium is abundant compared to lithium, and if the charging times are as good as they’re saying it might be worth the loss of capacity.

That's an interesting comment that might explain why we are using lithium instead of some other metal. Do you have a reference that discusses this?

Last time I looked what I read was lithium doesn't change size when it gains or loses and electron. Other metals the ions change size which damages the electrodes.

Heard that from an energy consultant, Jean Marc Jancovici, in his numerous interventions and conferences.

Yet batteries have steadily gotten better even since the introduction of lithium.

Reply on news.ycombinator.com