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Comment by belval | Hacker News Reader

For some reason people downvote you, but batteries seem to have this constant flux of N=1 articles explaining why X new chemistry is about to dethrone lithium. When it's not aluminium, it's solid state. This article itself has several red flags:

> In contrast, a typical Li-ion battery retains only 80 percent of its charge capacity after 300 to 500 cycles, depending on conditions.

LiFePO4 lasts for about 3000 cycles before 80% degradation, not 300-500.

> The batteries were also tested at temperatures as high as 200 degrees Celsius

Thermal runaway on LFP is 120C, not 200 but still not a temperature you will easily hit.

And finally (as always):

> before the Al-ion battery is ready for commercial applications, its energy density will need to be improved

Which means it's not commercially viable.

LiFePO4 is cheap to manufacture, uses lithium, iron, phosphate, all of which are fairly plentiful and lasts for over 3000 cycles (before reaching 80% capacity).

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In defense of them, 99% capacity retention after 10,000 cycles is still much better.

I wonder if they are quoting unrealistic 0-100% numbers and you are quoting realistic 20-80%. If so, and you multiply the Li capacity by 0.6, I wonder how far off aluminum's (undisclosed) density is.

On an unrelated note, I’m surprised that lithium is only 4x the price of aluminum. They’re both incredibly common elements, but lithium extraction is harder for a lot of reasons.

> 99% capacity retention after 10,000

This would be really useful for plugin hybrids, even if the density is not competitive with LFP for pure EVs.

Consumer gadgets too. I tend to replace the Li-ion batteries in my phones and laptops every 2 or 3 years and it's a pain. I'd pay extra for something that lasted a decade.

Consumer electronics use Lithium Polymer generally, which has one of the lower useful lifespans.

Just replacing it with LiFePo batteries would give you 4x the lifetime. Of course, with current technology the battery would have to be twice the size.

I don't think lithium is 4x the price of aluminum.

In January 2025, the North America price of lithium carbonate was $9.37/kg. But lithium carbonate is just 18.7% lithium, so the price is $50/kg of contained lithium.

In comparison, the current market price of aluminum metal is $2.62/kg. And aluminum compounds (where the large energy expenditure needed to reduce Al(+3) to the metal is not needed) should be cheaper.

Aluminum is much more common than lithium. It's the third most abundant element in the Earth's continental crust after oxygen and silicon.

> In defense of them, 99% capacity retention after 10,000 cycles is still much better.

Maybe, maybe not. The number that would actually matter is capacity in joules after 10,000 cycles, not the percentage.

> Which means it's not commercially viable.

Depends more on price than anything else. Maybe won't replace phone batteries, but a stationary battery for home or a utility-sized one that uses less temperamental chemistry would be very welcome.

red flag #1 is before the article even starts

picture of AA batteries

>Lithium-ion batteries like these currently dominate the market, but aluminum-based alternatives could be a better solution

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