Stabilization of gamma sulfur enables 4000 cycle Li-S batteries [pdf]
nature.com
nature.com
Yeah, there have been lots of "breakthrough battery tech" announcements that didn't lead to commercial products, but this one really looks like it may be just the leap forward that will make renewable energy storage a non-problem.
Although very important to note in these discussions: a lot of them did. Yes, in mass production as as part of a whole battery system vs a single lab cell the gains are almost always far smaller, but small gains add up over time. Energy density has dramatically increased over the last few decades [0] as well as cost dropping and those trends together have combined to make the current electrification acceleration possible. There isn't any need to be overly cynical about this stuff, the progress is real and a tipping point was reached a while ago. With the amount of capital for R&D and production pouring in at this point it's not unreasonable to hope for even more.
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0: https://arstechnica.com/science/2021/05/eternally-five-years...
Really? I haven't noticed much progress over the last 5 to 10 years. What was the biggest breakthrough that has materialized in that time?
You don't call doubling to tripling of energy density progress?
https://cleantechnica.com/2020/02/19/bloombergnef-lithium-io...
And it's not about "big breakthroughs" any more than it is for microprocessors. A bunch of lab changes that in production add .5-5% each add up to 10-20% in a generation add up to 2-3x over a decade. That something works in a lab though is still interesting since it shows the possible ceiling we can work towards. Going from that to something that we can make billions of cheaply entails compromises, but the ultimate envelope still matters.
I also found a 3200 mAh model from 2012: https://cdn.shopify.com/s/files/1/0481/9678/0183/files/panas...
That's a fair bit less than a 3x improvement over 10 years. Now of course this is a rather crude and unscientific measurement. It's also effectively measuring energy density by volume rather than weight, but volume is more often the limiting factor for Li-ion batteries (e.g. smartphones and EVs are volume limited).
Still, I think this shows why people are skeptical about claimed massive improvements in battery tech: it's hard to find clear evidence of it in actual products people can buy.
Laptops last a few hours, phones last around a day, etc. We’ve used that density to get thinner and lighter devices with slightly more performance that’s hard to observe from everyday tasks.
The outlier is cars, where they’ve crept up as the density has come up.
Has it really ? I remember the same mAh ratings or slight bumps in phones for many generations. 2016 Samsung galaxy s7 had 3000mah battery - latest ones have like 3700mah ? There have been larger batteries in bigger phones - but I'd like to have a 6000mah battery in a normal form factor.
The only doubling I see is in 10 year period, but phone size grew considerably in that time as well.
And smart watch batteries still suck no matter the price range.
While I doubt something like the Phoebus Cartel exists for batteries, when they all have little incentive to make them last longer, you won't find much difference between them. Exceptions include military and aerospace where the costs are also many times higher.
The cost savings would immediately solve the business case around renewable energy storage, too.
If this turns out to have the purported benefits at commercial scale, it could have an immense impact on our future!
That's not too realistic, a Model 3 battery only weighs half a ton to begin with. So perhaps we could cut the curb weight of the car by 15-20%. I wouldn't complain, but it's not world changing.
The impact of this for EVs would not necessarily be cars with bigger ranges but much lighter/cheaper cars with similar ranges as current high end models with faster charging times that only need a third of the battery weight. Anything beyond a few hundred miles of range is basically irrational and overkill. Normal people have a bladder range of about 200-300 miles at best (I get uncomfortable way before that) and ought to stop for longer than five minutes when they relief themselves eventually. Perfect opportunity to top up a battery. But most people don't actually drive that far more than a few times a year; if at all.
I see 300 possibly being sufficient but I’d want the advertised range to be 400 to make sure I reliably get that.
Absolutely true, but, until we move to a "usage" rather than "possession" model for cars, this will be the biggest obstacle to massive adoption of EV as the primary car.
At this point people get that they probably only run 100km a day at most, and that an EV would perfectly suit their daily commute (small EVs would be the perfect yellow jacket thing.)
However, everybody has family to visit on the other side of the country twice a year.
The moment you cross the psychological threshold of 1000km on a single charge (or, roughly a full day of highway), the whole game changes.
Would it be better if people commuted by train and ebike, visited their family by trains and had small easy to rent EVs for the days they need a car ? Sure. Will it happen before 70 years of cultural impact of personal car change ? Hard to tell.
Relatively few people drive across the entire country twice per year. Many Americans do drive several hours to visit their family.
It takes basically one trip using a current long range EV (e.g., ~310 miles range) and modern HVDC charging to rid yourself of these concerns. A 9h (~500 mile) trip only requires about an hour of HVDC charging. You'll need to stop for 30 minutes anyway unless you're on some kind of cannonball run.
Except that on the holidays, there will not be enough chargers, so the “30 minute stop” is an ideal that simply cannot be reached under peak holiday conditions. Booking a charger could make things predictable, but it can’t solve the problem of not enough chargers available during peak periods.
I don't think any TV is going to resist filming infuriated would-be-holliday-goers burning under the sun while they wait an hour or two to fill their batteries. The first summer it arrives will be _very_ hard for the EV industry.
Also, those "highway areas" are owned by... gas companies. So will they put their best will into making sure the EV-holliday experience is top-notch (maybe ramping up charging capacity with portable batteries during the summer ?) Or will they let the experience be hellish, look at the number of EV stagnating, and lobby like hell to move the ICE bans further to the future ?
The good news is, it will be technically possible for people to continue to buy cars they absolutely don't need for money they can't afford. Not going to be a problem. It's not really a problem now, really. Manufacturers will be more than happy to take your money.
You seem to assume people are thinking about cars _rationnaly_. I don't know about other countries, but at least in France, this is _not_ the case.
About 30 to 50% of the TV ad space is devoted to cars. The surge of SUVs in the last decade is caused by people buying _entirely irrational_ cars (way too big, way too heavy, with - sorry HN - way too much electronics.)
This is also the perfectly predictable result of marketing incentives (car dealers sell what they're told to sell.) EU has some regulations that _might_ make it unaffordable for car companies to keep the same incentives in the long run - but I don't expect them to play nice.
People will keep buying what their friends, car dealers, auto magazine, music videos, movies, and, mostly, TV ads tell them to buy.
We've been post-homo-economicus in this market for decades.
Now, the "second-hand" market is much more rational - but EVs are not there yet.
In fact even with coal the amount of CO2 will be smaller per distance driven. The efficiency of the latest coal power stations is about 48%. With this and accounting for significant energy losses to refine gasoline from oil the electrical cars are already greener than gasoline or Diesel engines unless one use the energy from very old coal plants with low efficiency.
An electrical motor is very efficient, a battery system is moderately efficient and combined with all environmental costs to source needed materials, dispose of end-of-life batteries (witch means 5 to 8 years per battery in mean) are huge. Of course pushing refined oil around the world is not efficient either but such infra is already there, while no country in the world can recharge their potential EVs on scale nor we can produce them in sufficient numbers nor we know how to dispose of them.
Costs should be computed in total, not just in the running part. Like cost of trains must take into account the construction of the train network, it's entertainment etc NOT just the energy the train use.
Well-to-wheel, covering every single CO2 molecule involved in producing, transporting, burning and consuming ANY fossil fuel used for electricity production, electric cars are still more efficient and produce less emissions per mile. You could turn over the entire fleet of cars on US roads to electric today, and charging them would not pose a problem for the grid.
Batteries do not reach end of life in 5-8 years. Every EV battery on the US market comes with a minimum of an 8 year 100K mile warranty, and they do not get disposed of the day the warranty ends. They have 10-20 years of usable life in a car, then another 10+ years as stationary storage with reduced capacity. When an EV gets totaled out, the batteries never ever go to a landfill, even 10+ year old ones, as they have so much usable life in them they're still worth thousands of dollars.
For one point of reference, a 10 year old Nissan LEAF EV battery -- which were tiny compared to the batteries that come in new EVs today -- will still have more usable capacity in it than a brand new $11,000 Tesla Powerwall for whole-home battery backup and solar storage.
Before the pandemic sent used cars prices to the moon, there were people buying used Bolts (and probably Leafs, I imagine) to park them permanently just to use the battery capacity for their off-grid home. Apparently it was cost effective, and the Bolt wiring is pretty straightforward to work with.
From the Real Life World®©™ instead of the advertised world. Did you ever have a lithium battery of any kind for more than 10 years? Try to look for real EV patterns: there is not much easy to access but actually daily used EV with a bit of mileage can't be used anymore, at the performance level the owner need after 5 years. Less used EV cease to be usable in around 8 years. After that sure, if you buy a Tesla just for weekly casual trip and have ICEs for daily use things change, you Tesla can potentially last even 15 years.
Also sorry but NO statistic, at least not one public, cover the pollution of lithium mining since that happen in exotic and poor places. Almost no one these days want to publish against the Green New Deal, it's seen like a classic patriotic act by many, unfortunately if you are intellectually honest and really an environmentalist you should know that from advertisement and reality there is a big difference.
100k miles came quickly for anyone who use a car for real, in 4-5 years actually BTW, and while ICEs cars have formally equal guarantees in mileage terms, they can last issueless for around 200k miles, and with not marginal entertainment till 400k. EU commercial vans, bus, trucks are used normally for 2 million km and some last other two in third world countries. So please be intellectually honest. Even carmakers publicly declare that with actual chemistry it's impossible going electric on scale except marginal markets like the (in)famous "glorified golf cart" and few luxury car.
If today all USA cars switch to BEV the USA electricity grid will collapse in few hours and can't recover even with continuous rolling blackouts for years, even here (France) with all NPP operational it will be impossible to recharge the actual ICE magically transformed to EV. That not counting the homes switching to heat pumps.
Just to gives you a realistic dimension this month I've used form grid 151.2kWh and from solar 209.18kWh, in January 460kWh from grid, just 171 from solar, that's in a modern home super-insulated with heat pump heating/cooling/cooking etc. If I count consumed diesel in kWh (around 1000kWh/month), well, I need to triple my small plant. And of course I need two car per head to be used alternatively to recharge them. Now try the same basic calculation for someone who live in an apartment and do not WFH nor that near home. Just to dimension mere energy needs, not counting costs (in natural and economical terms, producing capacity in natural terms etc).
That's the world I live in, but you are describing a world that's totally unlike it. Is "Real Life World" a fictional world you've invented and trademarked with a nonsensical name in order to confuse readers?
> Did you ever have a lithium battery of any kind for more than 10 years?
Yes, I have a 2012 Nissan LEAF which has a 24 kWh lithium battery pack. It is still working perfectly now after 10 years.
I also have a 2018 Nissan LEAF, a 2019 Kia Niro plug-in hybrid, and a 2021 Volkswagen ID.4. Suffice it to say, I have some experience with owning and charging electric cars in the real world.
> 100k miles came quickly for anyone who use a car for real, in 4-5 years actually BTW
The average car in your country reaches 100K miles when it's 14 years old, and in the US when it's over 8 years old.
> Just to gives you a realistic dimension... if I count consumed diesel in kWh (around 1000kWh/month)
You lead with "realistic", then gave a figure equal to driving about 4000 miles in an electric car every month. This is not realistic. Last month my electric cars consumed less than 150 kWh, or the equivalent of plugging in a small single room space heater for 3 hours per day. This fuel cost me about $20.
> If today all USA cars switch to BEV the USA electricity grid will collapse in few hours and can't recover even with continuous rolling blackouts for years
Converting 80% of all passenger vehicles to electric would only add about 10% to total electric consumption. Studies have been done, the grid would be fine.
From what I know, having experimented and seen that's can hardly been. Perhaps you use cars very little so they last longer and traveling just for short trips makes them usable for you even when they can just run 50 miles. But while that's a perfectly legit use case it's far from the mean use cases for all humans...
> Yes, I have a 2012 Nissan LEAF which has a 24 kWh lithium battery pack. It is still working perfectly now after 10 years.
After how many miles/km if I can ask?
> The average car in your country reaches 100K miles when it's 14 years old, and in the US when it's over 8 years old.
The average is meaningless, people living in major cities are a huge percentage of the population and use cars far less since in dense EU cities cars are a needed nightmare because just traveling 20km (~12 miles) demand 30'+ in good days and sometimes, few time per month, can demand hours. While people living outside those major cities travel much, much more. Where I live most travel around 50-60km/day (31-37 miles) around ~10+% travel 100-120km/day (62-75 miles) on average. I have few neighbors who bought Tesla, I see how much their batteries wire out, surely not linearly, but at a rate with their usage, that will make them useless in 8 years, they might last [1] 10+ years but with too little range to be useful. Not only, resale value is essentially zero here. No one want second-hand EVs, no one trust them. Use them to extract the battery to complement a domestic p.v. plant it theoretically possible but impractical since those batteries are not made in easy-to-extract modules, of course their are small cylinders inside, but practically recycle them is costly and complex enough that on scale the price of a new battery will not be much different than of an already dead one, counting it's residual life and fire risk.
> You lead with "realistic", then gave a figure equal to driving about 4000 miles in an electric car every month.
Diesel is rated 10.7 kWh/l (40.5 kWh/us gallons) I use around 60 liters/month (15.85 gal/month). You might counter that electric motors are more efficient BUT in practice they are just a little bit more because:
- I produce energy from p.v. so hopefully recharging out of my micro-plant means from DC (panels) to AC (solar inverter, ~89% efficiency) to DC again (car inverter-charger, probably around 60% efficient) means a big loss of energy;
- battery itself is around 90% efficient
- motors inverter from battery also loose power
Giving a scientific estimate is not easy, you also need to take climate into account, cars HVAC usage, ... but I think estimate a real total efficiency around 15% plus than an equivalent ICE car is realistic enough.
> Last month my electric cars consumed less than 150 kWh
I do not own and EV but I driven some, my mileage declared by their on-board systems was 150-210Wh/km driving normally, witch means ~270-378kWh/month. Assuming a similar consumption for you that means ~33km/day (~20.5 miles/day) witch is very, very little for anyone living outside a city.
> Converting 80% of all passenger vehicles to electric would only add about 10% to total electric consumption. Studies have been done, the grid would be fine.
Seen how much blackouts happen also in developed countries from Texas to Tokyo region just to cite some famous... I doubt that electricity grid can even satisfy actual demands. Since few years, France the most nuclearized country in the world have done very small rolling blackouts to remain at 50Hz. Swiss another big producer of electricity have had issues as Norway due to reduced hydro production. Just in the last years, with not much EV nor extreme weathers. If you imaging a "country wide smart grid" with cars connected to quickly step in if needed... That's a dream. Having a p.v. with lithium storage I see how quick a modern inverter is and the answer is not enough. If you add signaling and relevant vulnerabilities on scale instead of stabilize the big smart grid you crate continuous blackouts. Car's inverter will ripple anytime the load go down, fail to sustain frequency quick enough every time the load ramp up.
Consider a thing: EV actually can recharge super-slowly a 3kW/monophase or slowly at 7kW/monophase or 22kW/triphase (mandatory here for new houses and apartments parking since 2020 or so), actual grid consider around 6kW mean power per household, most apartments are 9kW maximum, most homes 12kW single-phase or if they have electrical heating, SPA, ... maximum 36kW. In some countries like Italy most households have just 3.3kW. And our grids are already in a tough situation now.
Consider that most will charge their car in the evening, no signaling infra exists to tells cars inverter when start to balance the charge in the night, no way to tell cars "when I need the battery full". P.v. start to be popular but so far most parking lot do not have p.v. and even those who have it can't recharge out of it more than few cars. Again no infra is in place and can't be done quickly.
Lithium earth resources are essentially unknown, but current estimates are not much optimistic and we still do not know how to recycle batteries. With the actual chemistry 80% of private vehicles can be EVs around 2050 if we push WFH much, something that start to happen just a little bit, with many resistances and schizophrenic behaviors.
That's what I call reality vs advertisement...
[1] if internal flash storage do not wire out before, https://www.tomshardware.com/news/flash-memory-wear-killing-... or an OTA upgrade block them https://www.theverge.com/2018/6/2/17413732/tesla-over-the-ai... or some other costly issue happen, costly enough to make convenient giving up
That not counting the environmental damage provoked by mining for solar panels and batteries. Not counting the fact that we already have issues satisfying electricity demand without much EV on the roads.
Sorry, I'm an environmentalist and an engineer, I know people like dreams, but I also know what we can have, so far the proposed new deal is simply a disaster. I've built my new house well insulated, with actual green standard, because that's a good and doable thing for those who can afford doing so and now I consume far less energy to heat/cool the house, that's good. If gas prices goes up a bit more I might benefit economically from an EV but that's not a green in environmental sense of green, that's dollar green. First we can't rebuild in a decade the 99% of existing buildings to lower energy consumption, it's good going fast in that direction, but we can reach that goal perhaps in a century, and "we" means in the western world only. That's do a good job for us, but it's only a part, even if big enough, of our energy needs. We have industry needs, transportation needs. For industry actual best option is nuclear (constant production per nearly constant demand in developed industrial systems) witch also work for ships, even if is hyper expensive. Some goods can probably be transported by intermittent rail service that move goods only when we have energy, but such commercial-only network is to be built and is a colossal and not flexible at all solution so probably not even worth the investments in environmental terms.
The sole Green New Deal I see theoretically possible is with a mass genocide that kill a large slice of humanity in very short time. With that scarce resources would be less scarce and so we can probably last longer enough to evolve if the reduced number of humans suffice to produce technological advancements witch is a bit uncertain, morality aside. Not counting the little issue of dealing with billions of death in a short time span and resulting social and biological consequences.
Really, try to imaging, to dimension a bit a possible new society and draw your conclusion, I've done that with what I know and that's what I conclude, I'm curious about others opinions. Remember in the game that even our small p.v. plant in modern houses are not born in the backyard and the supply chain and industry behind them need to been able to exists forever if we want to live with such model. Similarly EV does not born in our garage. Just to say I can produce around 25kWh/day in moderately good days, I use around 12kWh for my house in mean, try to design a recharge pattern for an EV. Extend the computation for actual population density and needs. Try to determine how much TWh we consume in gasoline for our cars and how much renewable we need just to recharge a hypothetical equivalent fleet of EVs. Do such basic and approximate math. Add to it, even if it's not needed, the energy we need for industry and for heating/cooling. Really try that instead of dreaming or swallowing advertisements like most do dreaming a miracle car with a solar roof that run autonomously as the owner wish.
The transition from a battery weighing 500 kilograms to one weighing 250 is something which I see as allowing electric cars from being highly specialized constructions to something needing much less care in their design. After all, there are ordinary cars with engines weighing 250 kilograms.
Imagined:
https://www.autocar.co.uk/car-news/new-cars/mercedes-benz-vi...
The Lucid Air can do 804 km which is pretty close to your target range:
https://insideevs.com/reviews/562511/lucid-air-range-test-re...
It’s really interesting because there could be so many ways to stabilize interesting new phases that conventional high throughput theoretical screening isn’t going to predict
[1] https://www.freethink.com/environment/lithium-sulfur-battery
I recently played around with the data from Germany 2020. I scaled up the existing renewables (only the ones that are scalable - wind and solar, hydro is pretty much maxed out) so that the yearly consumption can be served from 100% renewables. Then I added a battery to carry the overproduction over to the gaps. A 3 TWh battery would still lead to 50 days of empty battery and thus gaps in the power supply.
This is electricity, not Transport and heating. And obviously my approach is simple, no sector coupling effects, no smart grid just scaling up want we have.
3 TWh is 30 million Model S batteries. Even with sodium ion batteries I think this is not really realistic.
I always wondered why the are talking about hydrogen so much, despite the much higher losses you get in that process. Now I get it. I think batteries will be a good solution for single family homes / buildings with solar panel. But the grunt of the grid storage I think will be hydrogen. Especially because during winter, it can produce heat and electricity and the same gas turbines that are already common in German cities.
Either way, it's a big, hard project, but doable if we really want to.
I think water is more efficient then hydrogen even.
I guess that plant doesn't have an extreme amount of head or a particularly large reservoir.
It's about 7 minutes at https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta... , which has a lot more head.
So you need a lot more pumped storage if you want to start talking about days of backup, and we already used quite a few of the best sites.
m * g * h -> you either need lots of water or lots of height. Best is to have both. You only get that in the Alps and you need some special geoprgaphic features to make it work. Europe is also densely populated and the nature we have left, we want to preserve, so we can't flood all of it.
Do the math, figure out how big of damn we would need to store 3TWh.
My result: at 1000m pump height, you would need 3000 billion liters, which is cube of water with a length 1.5km. Double check this tough, I'm not sure if I did all the conversion correctly
For what it is worth, in Europe, Switzerland is doing a lot of pumped hydro powered by surplus French nuclear power in the summer time. Norway has huge amounts of hydro and only pumps a little, but it doesn't matter much: The Scandinavian grid is so well connected, that hydro will ramp down when power is available elsewhere, in effect providing on-demand provider for the whole region.
Then you'll get times with overproduction with very low prices, this will prop up "power to storage for power later" (liquid, gaz, whatever) with buy low sell high usual market stuff.
Note that France has currently 130 TWh of gaz storage capacity for about 473 TWh of yearly electricity consumption.
Did you use the approach outlined in https://doi.org/10.1016/j.euroecorev.2018.07.004 ? Because "50 days of empty battery" is vastly different from the results in that work. 3 TWh is roughly 0.5% of German annual consumption and should bring you to at least a 90% renewable scenario, if not to 100%.
My approach was very very simple: if production is higher than consumption, store energy. Energy storage is limited, so when the stroage is full, energy is lost. If consumption is higher then production, take the difference from the battery.
I have not considered any smart usage patterns or any advanced concepts at all.
Also keep in mind that this ignores transport an heat. Pure electricity was what I looked at and that is somewhat around one third of the total energy used in Germany.
That's not quite how I understood "50 days of empty battery", but fair enough. This is not something that can't be solved, though. Even the 90% estimate is the worst case estimate, since there's actually a high likelihood of 3 TWh of storage being sufficient for 100% of renewables in any given German year.
> My approach was very very simple: if production is higher than consumption, store energy. Energy storage is limited, so when the stroage is full, energy is lost. If consumption is higher then production, take the difference from the battery.
That's Sinn's approach ("waste no energy and store everything, no matter the cost"), which yields significantly higher total costs (and storage capacities) than Zerrahn's approach which actually takes costs into consideration and leads to much smaller storage capacities on the basis of throwing energy away or using it opportunistically being actually cheaper than storing it for later grid use.
> Also keep in mind that this ignores transport an heat.
Transport and heat actually simplify things significantly for the grid since charging of EVs in Europe can be shifted around by as much as several days while heat will have been largely solved by the EU's 2010 and 2012 energy efficiency directives.
Given that Germany has 60 million cars, that sounds not just realistic, but outright easy.
Luckily the EV market alone is enough to drive battery tech for short term storage forward, and green hydrogen for fertilizer is enough to take care of the rest. But, there's no need to wait, we should be a decade ahead on this at least if not for well funded lies holding us back.
The new material they discuss is for the cathode side (not anode). That's side where the lithium ions go when the battery is charged. The cathode of traditional Li-ion batteries is made of metal oxides: Cobalt, Nickel, Manganese (lately trying to get rid of the expensive Cobalt).
The sulfur cathode promises to remove all of the expensive metals in the cathode and make the cathode much more energy dense.
The anode is where the lithium ions go when the battery is being discharged. In traditional batteries the anode is made of carbon fibers (burnt coconut shells). The holy grail of anode is pure lithium anode - there is nothing more energy dense. But the problem with pure lithium is that it tends to get deposited not in an even layer, but in the form of dendrites that eventually poke through the dielectric separator creating a short. In this work they explored lithium anode, but as I understand that was not the main focus. I don't think they solved the dendrites formation problem.
Am I missing anything obvious that would imply the cycle stability is limited to 4000? From the trends it seems to me that the headline is understated and these might last much longer than 4000 cycles.
The micrographs of the nanofiber composite electrode are cool!
So lithium titanate, lithium cobalt, lithium manganese oxide, nickel cobalt manganese(NCM), nickel cobalt manganese Aluminum(NCMA), lithium iron phosphate(LFP), and now lithium sulfer are all related but they have very different trade offs. 15 years ago Li-Ion battery tech meant worse trade offs so fewer charge cycles, slower charging, less energy per charge, more costly etc etc.
And yes, NCM and NCMA both use lithium.
Some hot takes:
- Price per cell has dropped ~97% since 1991
- 1991 energy density ~200 Wh/liter; 2005 energy density ~500 Wh/liter; 2017 ~700 Wh/liter
[0]: https://pubs.rsc.org/en/content/articlelanding/2021/ee/d0ee0...
https://arstechnica.com/science/2021/05/eternally-five-years...
Now and again there's an actual advance and we rejoice, but if you keep an eye on cutting edge stuff it's got to happen a lot that some promising lead leads nowhere.
If you goal is to learn about things once they're stable and working, I suggest drop reading science journalism from your schedule and just start window shopping at electronics stores.
[italics mine]
These are bold claims. You don't hear that every day. Polysulfides have been an accepted fact of life in Li-S batteries forever.
Among these are: ability to mass produce, resistance to mechanical stresses, safety, peak performance, low auto-discharge, ability to recycle, energy density, charge cycles, efficiency, availability of materials, operational temperature range, storage temperature range.
The latter criteria seem to be well addressed in the paper, the first few not really, or only tangentially (based on a quick ctrl+f for some of the key words).
But the abstract says that they're made using sulfur stabilized by[1] carbon nanofibers[1]. Great: now make a million of them.
1: EDIT: nanofibers stabilize the sulfur, but it is not encapsulated. The phrasing "within" in the abstract threw me for a loop.
Material synthesis Synthesis of CNFs. The free-standing CNFs were made by electrospinning. Typically, 10 wt% polyacrylonitrile, was added to DMF and stirred overnight to form a polymeric solution.
This solution was then loaded into a Becton Dickinson 5 mL syringe with a Luer lock tip and an 18-gauge stainless steel needle (Hamilton Corporation). The syringe with the needle was connected to a NE-400 model syringe pump (New Era Pump Systems, Inc.) to control the feeding rate of the solution.
The grounded aluminum collector was placed 6 in. from the tip of the needle. Electrospinning was performed at room temperature with a relative humidity below 15%. A potential difference of 7–8 KV (Series ES -30 KV, Gamma High Voltage Research, Inc.) was applied between the collector and the tip of the needle. The flow rate of the solution was kept constant at 0.2 mL h−1.
The as-spun nanofibers were collected and stabilized in a convection oven at 280 °C for 6 h in air atmosphere.
The stabilized nanofiber mats were then placed in alumina plates and carbonized in a nitrogen environment up till 900 °C at a ramp rate of 2.5 °C min−1 and then activated under CO2 flow for 1 h in a horizontal tube furnace (MTI. Corp). The furnace was then cooled at 2 °C min−1 until it reached room temperature.
Monoclinic γ-sulfur deposition on CNFs. The free-standing CNF mats were pun- ched with stainless steel die (φ = 11 mm) and dried at 150 °C overnight under vacuum.
The CNF discs were then weighed and placed in an in-house developed autoclave (Stainless steel 316) and subjected to 180 °C for 24 h in an oven. The autoclave consisted of a sulfur reservoir at the bottom and a perforated disk for placing electrodes at the top. After 24 h the autoclave was cooled to room tem- perature slowly in a span of 6–8 h.
The electrodes were weighed and transferred in an Argon-filled glove box via overnight room temperature vacuum drying in the antechamber for battery fabrication.
>we stabilize a rare monoclinic γ-sulfur phase within carbon nanofibers
and my mind jumped to "sulfur inside a nanotube again". But the sulfur isn't "within" the carbon nanofibers, as they later specify, and this is new.
>We demonstrate that despite an exposed “un-confined” deposition of this sulfur phase on the host carbon material, the carbonate-based battery exhibits high reversible capacity
The sulfur is in contact with the electrolyte. And it works! That's not supposed to happen, but now it does. So the process you described doesn't make carbon nanotubes, it makes nanofibers, which are much simpler (you don't need axial concentric planes).
The only commercial batteries I know of that can do that are Lithium Titanate/LTO, that you can mostly only buy on AliExpress and a few specialty places, and are almost unheard of in commercial products(Except maybe some wireless earbuds and capacitor-like applications).
They have like 1/4 the energy density or something, but they are still really amazing. I'd love to see power tools use them, we could run tethered on a USB-PD, charging during idle periods, and not wear out from cycling.
Yeah, any new tech will be expensive. In theory, once it hits mass production it should be cheaper than existing li-ion since it doesn't require cobalt or nickel. I'm hoping it works out and hits similar price as today's batteries by 2030. But I'm probably too optimistic.
It feels like we're betting on the wrong thing, and in the process blowing our wad and good will. Kind of like what happened with nukes.
Current tech tends to improve at a steady pace.
Taking a new tech to production takes some years (somewhere in the 5 to 20 years range); processes need to refined and scaled, suppliers sourced, people trained, recycling must be addressed etc.
So new tech only stands a real chance if you can convince investors that its advantage is big enough that it still dominates when it comes to market.
Let's say current batteries improve 7% per year (number made up, but not totally unrealistic). If the new technology needs 10 years to get to market, the current technology improves by a factor of 1.07*10 = 1.97 in mean time. So a 2x advantage along any axis (density, charge cycles, price, availability of materials etc.) is not a solid bet for an investor. A 5x advantage likely is.
If course you'd want advantages on multiple axes to really make a solid bet.
EV batteries also aren't a monoculture. They are even mixing battery types in EV packs to achieve different range/cost aspects.
If there's room for Sodium Ion, LFP, and the various cobalt/nickel chemistries, if there's air, sea, and long-haul modes plus grid storage, home battery storage, plus all the mobile and tools, there's plenty of segments.