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Comment by Retr0spectrum | Hacker News Reader

It seems like we're always hearing about the next big thing in battery technology, but they seem to stay in research forever, and never hit the consumer market.

The most exciting part of this, is that they say the'll be in consumer devices early 2017.

I'd love to have one in my quadcopter!

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Yes, if we had all the "2x improvements" in batteries from press releases, batteries would be powering airliners by now.

"Yet just as safe and long-lasting as the lithium ion batteries used in consumer electronics" is not happy-making as energy density increases. The existing lithium-ion technology just barely keeps from overheating and blowing itself up, and it takes about six safety devices to prevent that. (Latest major hoverboard explosion story: [1] All those safety devices really are needed.) Lithium metal batteries (available now as non-rechargeable batteries) are even more dangerous, and are currently prohibited on US passenger-carrying aircraft. Lithium metal battery fires require a class D (flammable metal) fire extinguisher.

They're vague about the safety issue. "We're going to make the anode ultra-thin" is a concern. There are safer battery technologies, such as lithium iron phosphate. That won't run away thermally, and passes the "nail test", where a nail is driven through the battery. Less capacity than regular lithium ion, which is why it's not widely used, although you can buy such batteries commercially from A123. "Boosted" skateboards use them, because they don't blow up.

Solid Energy Systems, submit your cell for UL testing. Otherwise, lithium metal is, literally, not going fly.

Company website: [2]. Uses the common "all hype no info" template.

[1] http://wsvn.com/news/local/hoverboard-explosion-causes-house... [2] http://www.solidenergysystems.com/

All sorts of problems with lithium-metal as we know it. A more benign version pitched by ZAF Energy is zinc-air. They inherit a few problems from pure metal electrodes (like dendrite growth) but not its thermal volatility. On the flipside, the performance increase will practically be not more than 2x that of lithium-ion.

ZAF had a very in-depth visit at Microsoft Research in June 2015. It is interesting to see the tribulations of a startup in commercializing technology that might become feasible but isn't quite yet and maybe never will. The 1h+ pre-sale meeting was taped [0] and I have an article in the writing about it [1].

[0] https://www.youtube.com/watch?v=xWwvHPaimlU

[1] https://docs.google.com/document/d/1R5gkh_A2vb6mDI5-e-EBlvP8...

> The existing lithium-ion technology just barely keeps from overheating and blowing itself up

This is somewhat due to the underlying technology, but more largely due to the prevalence of cheap counterfeits/knock offs scattered throughout the supply chain.

Lithium-sulfur batteries look like the most possible candidate as the next incremental evolution of the lithium ion batteries. Lithium metal... not so much.

But I really hope for revolution in this space, rather than incremental changes. This will boost and give wings to so many other inventions.

Lithium-sulfur only works hot. It may be a great option for huge batteries connected to the power grid, but plugging a 200°C inflammable battery to your laptop might not increase its safety.

You must be talking about the flow version of lithium-sulfur. The ones with (presumably) graphite and cobalt oxide electrodes are going into e-scooters in China now [0]. However, they are yet far from the theoretical 2x in volumetric density of lithium-ion.

For a very good survey on the state of the art in lithium-sulfur look up this recent study [1].

[0] https://twitter.com/openbatt/status/766641735229464576

[1] http://doi.org/10.1039/C5CS00410A

Note that having a compressed energy ready for rapid release is exactly equal to handling an explosive in your laptop :)

There are a lot of experimental batteries that have like 5x capacity of the current Li-ion ones, but melt and explode when heated or crushed, which makes them effectively useless.

This is one of the hardest problems in high-capacity batteries - to avoid "rapid unscheduled heat dissipation" and the following "rapid unscheduled disassembly".

> Note that having a compressed energy ready for rapid release is exactly equal to handling an explosive in your laptop :)

Animals can store a lot of energy, but they don't tend to explode with that energy when damaged. Are there techniques that could be learned from cells that could be used to make safer electrical batteries?

Fat does have much higher density of energy than Li-ion cell and it does not explode, but nobody seems to have figured out how to burn fat in closed space so that no exhausts are produced (there is always at least CO_2).

The videos of punctured lithium-ion batteries violently spewing smoke and flames is alarming.

Then there is Li-Po which can ignite if charged too much or if left to drain to low. I also suspect they'll burn if you give them a stern look or make a hurtful comment.

Yet you can take those on a plane but not a >100ml bottle of water.

Ok so that rules out phones, laptops and other devices that tend to get roughed up over time but I would still consider using it as energy storage for the solar panel on my house for instance.

As you have it isolated from the house in a specially built enclosure or garden shed it's less likely to get damaged and even if it is the damage can be manageable.

Then again in these cases it's more of a matter of how cheap it is vs the amount of energy it can hold and size doesn't matter a much.

Where weight and energy density is not a concern, you'd just use regular old-fashioned lead-acid. Lots of charge cycles, easily recycled, simple, no overheating, existing infrastructure.

When the Powerwall was announced, weren't people explaining one of the benefits over lead-acid based systems as you don't have to worry about accidentally generating noxious or explosive gases if the system isn't well vented? I just found something regarding that[1], but I'm unqualified to know how much of a problem this is in reality.

1: http://goodforgas.com/hazardous-gases-associated-lead-acid-b...

Well, outside my house at a safe distance. But yes, better batteries as a utility company thing don't need to be as safe since they can be outdoors behind a fence like a propane tank.

For large stationary batteries the number of charge cycles you can get is a major factor.

In that case, maybe what's actually needed is not battery capacity, but quicker and more convenient recharging systems?

Say solar, kinetic, or wireless charging stations spread throughout a city? Maybe incorporate some kind of "witricity" into the next WiFi proposal? If stuff can be recharged while it's being used, or within seconds, it shouldn't matter how much capacity the battery has.

..or an inherent groundstate failure mode?. I.e. the condition-based lowering of the activation energy of an endothermic crystalization. I don't know how feasible it would be though.

Yeah, with the batteries becoming so powerful, I sometimes feel uneasy about having the equivalent of a hand grenade on my lap and the equivalent of a potent firework right by my ear as I make phone calls.

> but melt and explode when heated or crushed

But that’s exactly what Li-ion batteries already do. x)

What you really want to avoid is destroying non-rechargeable lithium manganese batteries, like a CR123. There are some true horror stories out there, like this one:

http://www.candlepowerforums.com/vb/showthread.php?120888-RO...

TL;DR: guy used stock flashlight with two stock CR123 batteries in series. One discharged faster than the other, so it got reverse charged from the one holding more charge, and promptly vented hydrogen gas that got ignited and blew up. Guy got glass and metal shrapnel damage to his foot, and hydrogen fluoride poisoning resulting in permanent lung damage and other bad symptoms. It's really horrible. Bad stuff starts at page 5.

https://www.youtube.com/watch?v=fG_UuPmLO1c

With nasty cough as a bonus

Wow, that was an incredibly unsafe thing to do. I guess I shouldn't be surprised that they weren't at least doing it outside, much less under a vent hood or at least wearing good masks.

Also known as 'Engine rich exhaust'

Progress in batteries has come a long way in the last 20 years. It's one of the reasons your quadcopter is even possible.

Undoubtedly, but my impression is that it's been more of a gradual refinement of the same technology, rather than a sudden 2x improvement as claimed here.

Well, there have been clear technological jumps. I remember the time when the mainstream technology for electronic gadgets was NiCd. Then came NiMH -> Li-ion -> Li-Po. The differences are quite significant.

Li-Ion is nearly as old as NiMH. They coexisted for a long time, on very different price levels. When people think of battery progress, they usually just think of how LiIon got cheap enough for a use case that was on NiMH before. That certainly is also progress, but of a very differed kind than what they think it was.

I think it is clear progress if manufacturing becomes so much cheaper that the technology is actually available to more people.

It is progress, but because of the price-enabled technology switch, there are many misconceptions the kind of progress and its expected continuation. Outside of fixed installations, price only translates to capacity when there is a next level technology available at a higher price point. I don't see that now.

We might be left to forever squeeze out the last remaining bits of inefficiency from current technology (non-reacting mass fraction due to insufficient surface area per mass?)

Do you know of anywhere that charts improvements in commercially available batteries? I have a similar impression to OP, but only based on anecdotes.

https://www.reddit.com/r/teslamotors/comments/29mxnz/the_pro...

"2010 (early) Max. capacity 2600mAh (This has existed before)

2011 (early) Max. capacity 2900mAh/3000mAh

2012 (early) Max. capacity 3100mAh

2012 (mid) Max. capacity 3400mAh

2013 (late) Max. capacity 3600mAh (Are not yet common)"

3600mAh is apparently still the max capacity available.

Battery capacity doubles every nine years.

I'm not narcissistic enough to give this "law" a name.

The opposite is also probably true. A battery technology that promises to double today's capacity is at least 9 years away from being commercially available.

Sure, of course. It's not like the amateurs used combustion engines in their flying models for decades.

Once production at scale comes into play most of these "breakthroughs" result in sub 10% gains annually. But 5%-10% yearly battery progress compounds over decades to be gargantuan improvements.

Think of Rule 72, a 7.5% annual battery improvement rate compounds to a doubling every 9.6 years, which is amazing.

This one seems more plausible because it's not about making rechargeable batteries denser, it's making lithium-metal batteries rechargeable. We already know they can achieve this density.

Relevant xkcd: https://xkcd.com/678/

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