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Australia first to test new lithium-sulphur batteries

43 points| ntalbott | 6 years ago |newscientist.com

54 comments

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glutamate|6 years ago

This is a much better article with more technical details yet accessibly written: https://www.newscientist.com/article/2228681-a-new-battery-c...

Publication link: https://advances.sciencemag.org/content/6/1/eaay2757

mtgx|6 years ago

That first article title is so bad, mainly because those who have been following the smartphone industry for years know that if given access to such battery technology smartphone manufacturers would just add 8k screens, Threadripper-level CPUs, and hardware accelerators for mind-reading AI (so they can better target ads at you, not for anything remotely useful, obviously...) - all likely resulting in slightly less battery life than your phone has today, or at best a little more.

philipkglass|6 years ago

However, lithium-sulphur batteries may face similar ethical problems to lithium-ion batteries. The metal oxides in lithium-ion batteries are typically nickel, cobalt or manganese, which are expensive and diminishing in natural stores. They also have associated ethical problems: a significant proportion of cobalt is sourced by child miners in the Democratic Republic of the Congo, for example.

“In order to have much cheaper energy and more ethical batteries, we need a radically new energy storage system,” says Shaibani. The researchers will further test battery prototypes with a view to manufacturing them commercially in Australia in coming years.

It appears that Shaibani is saying that their new battery chemistry is an example of a radically improved battery that removes ethical problems while it improves energy density. The way the New Scientist article is written, that preceding paragraph makes it sound like Shaibani's new chemistry still needs improvements to remove cobalt.

There is already no nickel, manganese, or cobalt in this new lithium-sulfur cathode (nor in most lithium-sulfur cathodes). See Table S1 in the supplementary table for elemental analysis:

https://advances.sciencemag.org/content/advances/suppl/2019/...

scythe|6 years ago

I've read dozens of papers on Li-S over the years because of how much incredible potential the technology seems to have. The "dirty little secret" seems to be not the charge cycles (which are less than, but similar to, other batteries), but the large amount of electrolyte required, which reduces the effective energy density of the battery. There are all sorts of papers reporting high-capacity and durable cathodes but fewer that address the electrolyte problem, so I'm curious to see what their plan for that is.

A few papers about the electrolyte problem are e.g.:

https://pubs.acs.org/doi/abs/10.1021/acscentsci.7b00123

https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.2017059...

foxyv|6 years ago

For utilities I don't imagine that electrolyte is a big issue as there is plenty of space and you aren't lugging them around like you are in an EV. Maybe their plan is to use it mostly for grid power?

lolc|6 years ago

Sounds too good to be true! Did I read right? A fourfold increase in capacity with no downside? Going to production this year? How did I miss this until now?

rasz|6 years ago

Yes, definitely fourfold, shipping in 5 years!!1

Meanwhile Li-ion batteries were invented in seventies, it took 20 years to commercialization. First cells had 100W h/kg, and 30 years later we are slowly approaching 300W h/kg.

jpm_sd|6 years ago

Sion Power has been working on this technology "since 1989".

https://sionpower.com/about/

It still only lasts a couple of hundred charge cycles before wearing out:

https://advances.sciencemag.org/content/6/1/eaay2757

"The cells are stable for more than 200 cycles..."

clutch89|6 years ago

You misread that, it doesn't wear out after 200 cycles, it maintains 99% efficiency after 200 cycles.

Retric|6 years ago

200 charge cycles at 4x the storage = 800 lithium ion charge cycles. That’s easily competitive. Put another way if your getting 300 miles of range a current EV that’s 300 x4 x200 = 240,000 miles.

brink|6 years ago

Am I correct in assuming that a four-fold capacity in electric vehicles is coming? That will likely decimate oil dependency.

Gibbon1|6 years ago

Two thoughts of mine.

A twofold improvement in capacity would kill gasoline cars dead. That's 300 miles of range out of a 600lb battery. Adding up the weights of various components the electric car would weight about the same as a gasoline one.

While the failure modes of metal lithium anode batteries are terrifying that's probably okay for grid applications. Difference between a cell phone stuffed under a pillow and a battery in a concrete vault at at substation.

WhompingWindows|6 years ago

Best not to assume anything about battery breakthroughs - there's one reported every week.

Many companies are on the fore-front of batteries...if this chemistry is legit and available, you will know when Tesla or LG chem or one of the big players buys this groups' IP.

vocatus_gate|6 years ago

Reduce it by a tenth?

hanniabu|6 years ago

> That will likely decimate oil dependency

Until subsidies are increased...

Pet peeve of mine is how big business like to champion capitalism, but when they start failing they no longer like those rules and want government help to stay relevant and afloat.

JoeAltmaier|6 years ago

Lithium-Sulphur has high energy per kilogram which makes it good for transportation. Also high energy per dollar to manufacture which makes it good for grid storage (where weight and size don't matter too much, but cost does).

At the nominal rate of 750 amp hours per kilogram for lithium-Sulphur is well above normal lithium-ion batteries. But compared to gasoline, it raises the bar from 1% vs gas, to 2%. Do I have that right?

AnthonyMouse|6 years ago

What makes electric cars viable isn't that batteries have anywhere near the energy density of gasoline, it's that if you use them, you get to replace half a ton of engine, transmission, alternator, fuel pump, emissions and exhaust with a <100 pound electric motor, and have that cost and weight budget to use for batteries instead.

This naturally makes battery improvements a huge win. If you double power density you can cut the weight of the battery by more than half for the same range, since not only do you get the same power from a lighter battery, now the car is lighter and requires less energy to accelerate.

ajuc|6 years ago

Electric cars are about 3 times as energy-efficient as ICE cars. So it's not 1% to 2% but 3% to 6%. And with other savings (much lighter engine, no need for transmission) it's even better.

The problem is with degradation - it seems the new batteries only last 200 cycles.

zackmorris|6 years ago

Gasoline has about 33 kWh/kg (118.8 MJ/kg):

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

Unfortunately, internal combustion engines have a pathetic fuel economy since they run at low temperatures (around the boiling point of water). All heat engines are limited by the Carnot efficiency, which improves with higher temperature differential. In practice, other cycles like Otto, Diesel, Rankine and Brayton are lower than Carnot and improve with things like higher compression ratio:

  Carnot efficiency = (T.hot - T.cold)/T.hot
  where T is in Kelvin
https://en.wikipedia.org/wiki/Thermal_efficiency#Carnot_effi...

A low compression, naturally aspirated engine running at room temperature with nothing done to improve fuel economy runs at (373.15 - 298)/373.15 = 20% efficiency. I've heard figures as low as 8% for rubber meets the road efficiency in older passenger cars, which I believe, since we drove a ’68 Cadillac that got 5 mpg back in the 90s when gas was under $1 per gallon.

The best modern high compression engines typically achieve 25-30% efficiency at best. So I figure there are about 8-10 kWh/kg (28.8-36 MJ/kg) available in gasoline with modern vehicles. Cars built before ‘70s efficiency standards would be more like 2.5-3 kWh/kg (9-10.8 MJ/kg).

Unfortunately, it's not just that people don't care how ridiculously inefficient their vehicles are, it's that politicians corrupted by the fossil fuel industry and vehicle manufacturing lobbies never stop conspiring to lower efficiency standards:

https://www.vox.com/2019/4/6/18295544/epa-california-fuel-ec...

But I digress.

Electric motors typically run at about 95% efficiency, so we can probably assume 90% efficiency to the road. That’s over 10 times more efficient than classic cars!

Looks like Tesla lithium ion batteries are 0.254 kWh/kg (0.914 MJ/kg):

http://theconversation.com/teslas-batteries-have-reached-the...

Which is very close to the theoretical ideal for lithium ion of 0.294 kWh/kg (1.058 MJ/kg):

https://en.wikipedia.org/wiki/Energy_density#Tables_of_energ...

I'm having trouble finding energy densities for the new lithium sulfur batteries:

https://advances.sciencemag.org/content/6/1/eaay2757

https://advances.sciencemag.org/content/advances/6/1/eaay275...

I'm going to use their low number of 1200 mAh/kg, working between 1.7 and 2.5 V, so averaging 2.1 V (which is very inaccurate without integration), we can call it about 2.520 kWh/kg (9.072 MJ/kg). That would be about 10 times denser than Tesla batteries. Maybe they are estimating half the density in the real world due to packaging or something, in order to arrive at their "5 times longer battery life" headline.

So anyway, the real numbers are:

  Gasoline       33 kWh/kg    118.8 MJ/kg   (ideal)
  Gasoline       8-10 kWh/kg  28.8-36 MJ/kg (actual for modern vehicle)
  Gasoline       2.5-3 kWh/kg 9-10.8 MJ/kg  (actual for pre-70s vehicle
  Lithium sulfur 2.520 kWh/kg 9.072 MJ/kg   (ideal)
  Lithium sulfur 1.260 kWh/kg 4.536 MJ/kg   (actual)
  Lithium ion    0.294 kWh/kg 1.058 MJ/kg   (ideal)
  Lithium ion    0.254 kWh/kg 0.914 MJ/kg   (actual for Tesla)
My numbers might be off by a fair amount, but the important thing here is to think in orders of magnitude. Lithium sulfur is halfway to the energy density of classic cars and aircraft, with all the positives, like electric motors having 10 times the power as gas engines by weight, much higher torque, and substantially higher endurance/simplicity.

riazrizvi|6 years ago

Four decisions to make on cookies before being able to read the article? Are you trying to break the internet?

davidhyde|6 years ago

I'd recommend using using "I don't care about cookies" and "Cookiebro" to restore your sanity. Basically you want to automatically accept all cookies, say yes to all cookie banners, then remove all cookies when you close the browser except the ones you explicitly want to keep (for staying logged into certain sites). Those two firefox extensions facilitate that.

betoharres|6 years ago

funny how I saw many posts about Amazon fires and while Australia is burning to the ground(which is showing to be much worse than Amazon fires), I can only see a post about some battery; this makes me question this website..

fooqux|6 years ago

First of all, it's hacker news, not a general news site. And while the width of breadth of the type of news you'd find on here is larger than just coding and other hackery, it's still at least usually based in technology. Like batteries. Still, the official guidelines say anything "a hacker might find interesting" and we seem to be a environmentally-minded bunch, so maybe it would fly.

Second, it's based on use submissions. You think we should know something interesting about the AU fires? Submit a good article about it I guess. If I and others learn something interesting, it'll get voted up. That's how it works.

nrzd|6 years ago

It’s Monash University, not a news website, so doesn’t seem odd to me.