
Study identifies main culprit behind lithium metal battery failure - clouddrover
https://jacobsschool.ucsd.edu/news/news_releases/release.sfe?id=2850
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bigiain
If they can get close to that doubling of the energy density of Li-ion they're
claiming, that'd make a _big_ difference to the electric passenger flight
space. Possibly a game changing difference. Way more significant I think than
doubling electric car range (or halving electric car battery weight/cost).

~~~
oppositelock
So, avgas has about 45 MJ/kg energy density, lithium ion batteries have 0.5
MJ/kg. Aviation engines are maybe 30% efficient, while electrics are about 90%
efficient, so we've got about 15 MJ/kg usable versus 0.45 MJ/kg usable. Double
the energy density of a lithium battery, and you're at 0.9 MJ/kg usable,
versus 15.

We're not there yet to propel airplanes with batteries, not useful ones,
anyway.

~~~
fulafel
The current planes fly enormous distances - 15000 km - without refueling. (And
there is not a lot od evidence that even this is fuel mass limited.) There are
a lot of 2000 km routes to be replaced, like most countries' domestic flights.

But yep, it's not a solution for keeping our current flying habits. We will
have to cut down on flying, a lot.

~~~
AmericanChopper
If you solution to a problem is “massive reduction in critically important
infrastructure”, then you might not have a solution.

~~~
tonyedgecombe
Flying on such a huge scale is a relatively recent occurrence, very little of
it is critical, the world isn't going to end because you can't holiday in
Bali.

~~~
AmericanChopper
Airports are a part of every country’s critical infrastructure.

> the world isn't going to end because you can't holiday in Bali

Perhaps not. But the Balinese economy would simply collapse. I’m sure the
Balinese economy is of critical importance to the ~4 million people who live
there. What you’ve chosen as a contrived example doesn’t even illustrate your
point.

~~~
tonyedgecombe
On the other hand: [https://www.worldcrunch.com/food-travel/how-mass-tourism-
is-...](https://www.worldcrunch.com/food-travel/how-mass-tourism-is-
destroying-bali-and-its-culture) perfectly illustrates the problems with your
thinking.

~~~
AmericanChopper
My thinking doesn’t have anything to do with it, it’s simply a fact that 80%
of Bali’s economy is tourism. An industry specifically promoted by the
Indonesian government as a long standing policy.

“But, what if tourism wasn’t critical to the Balinese economy, what if they
had instead spend the last 50 years developing a different industry” you might
say. Well, who knows. But they didn’t, and the criticality of air travel to
Bali is not up for any meaningful debate.

~~~
Tharkun
This argument doesn't hold much water. Sure, it might be technically correct
for Balinese ecomomy. But lots of people fly lots of places for very
capricious reasons. If vacation is the goal, then everyone can go on a trip a
bit closer to home without flying. Certain major tourism centers will lose
out, but on average, there will be just as many tourists, just in different
places.

Air travel is far too cheap, everything else follows from that.

~~~
AmericanChopper
So we’ve gone from the idea that air travel wasn’t critical infrastructure,
with Bali as the example, to essentially saying “but what if the world was
completely different from the way it actually is”. Does that mean you agree
that it is critical infrastructure?

> Air travel is far too cheap, everything else follows from that.

This is another outrageous claim. All aviation accounts for about 2% of global
emissions.

The people commenting in this thread have chosen tourism, presumably because
they think it’s the most frivolous source of aviation emissions. But even this
is obviously critical to global economies. On top of that, the proposed
solution amounts to complete economic isolationism. An idea I’m honestly
surprised to see promoted on HN.

Suggesting that the world could possibly completely different from the way it
actually is, and that the foundations of the global economy aren’t necessary
isn’t suggesting a solution. It’s just utopian navel gazing.

~~~
tonyedgecombe
That 2% figure is dubious, most reputable sources put it at 4%. On top of that
the IPCC has estimated that the climate impact of aircraft is two to four
times greater than the effect of their carbon dioxide emissions alone.

~~~
AmericanChopper
The 2% number is from the IPCC, and carbon emissions from planes have the same
climate impact as carbon emissions from any other source (according to the
IPCC). But just for the sake of argument, let’s say the number is much higher
than that. Let’s say it was 10%, 5x higher than the IPCC claims it is. It
still poses a negligible impact to the climate, and has the least ROI or any
of the major contributors to carbon emissions. Electricity consumption is by
far the biggest contributor, and is by far the easiest to solve. If we were to
solve those problems, there’d be no need to even worry about aviation at all.
This idea that all carbon emissions are terrible and must be eliminated is
entirely counter productive, and entirely impossible.

~~~
tonyedgecombe
A special characteristic of aircraft emissions is that most of them are
produced at cruising altitudes high in the atmosphere. Scientific studies have
shown that these high-altitude emissions have a more harmful climate impact
because they trigger a series of chemical reactions and atmospheric effects
that have a net warming effect.

This is what the IPCC is referring to when they say the climate impact is two
to four times greater than from emissions alone.

 _This idea that all carbon emissions are terrible and must be eliminated is
entirely counter productive, and entirely impossible._

We have left it too late, our only choice now is to do everything we can.
There is plenty of air travel which is of marginal economic benefit that we
can drop.

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inflatableDodo
I wonder if you can make them 1D, so you have cells comprised of channels with
a lithium whisker at either end, then you shuttle ions up the channel in
between the whiskers and they can't get lost.

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mrfusion
Why does the anode make such a difference? I always picture it as a little
thing at the top of the battery. Does it actually make up a large part of the
batteries mass?

Isn’t the electrolyte where the energy is actually stored?

~~~
teraflop
The cathode and anode of a battery are not just the little metal terminals;
they are the sites where the electrochemical reaction takes place, and where
the energy is stored. Even in an old-fashioned alkaline battery, they run the
entire length of the cell:
[https://en.wikipedia.org/wiki/Alkaline_battery#Chemistry](https://en.wikipedia.org/wiki/Alkaline_battery#Chemistry)

(For one thing, the surface area of contact between the electrodes and
electrolyte is a limiting factor for how fast the reaction can proceed, and
therefore how much current the battery can produce.)

In a lithium-ion battery, the cathode and anode are typically constructed out
of many stacked layers, separated only by a very thin layer of electrolyte.

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imulligan
This serves as a follow up to India's discovery of a an Iron Ion battery that
is literally cheaper than lithium and lasts longer...

~~~
neximo64
Not even sure how its a "follow up" as it has nothing to do with the Iron-Ion
battery. Lithium is lighter & more energy dense and will take more chance.

I think where you're coming from is likely something like this Lithium battery
steals the press thunder from the Iron ion battery. It's likely the Lithium
battery will be used in portable, vehicle applications and if it actually has
any benefit the Iron would could be used to store surplus electricity for the
grid.

