Publication link: https://advances.sciencemag.org/content/6/1/eaay2757
“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/...
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...
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.
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..."
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.
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.
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.
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?
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.
new weight for energy density calculation = (total battery weight) - (ICE component weight) + (electric motor weight)
And battery packs have cooling systems too. So no savings there.
Specific energy (watts-hours per kilogram) is the entire ballgame with batteries and transportation.
The problem is with degradation - it seems the new batteries only last 200 cycles.
Don't fool yourself - there's a transmission element in an electric car too. The power has to get to the wheels, regardless of the power plant.
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
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)
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.