[HN Gopher] Lithium-sulfur battery retains 80% charge capacity a...
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Lithium-sulfur battery retains 80% charge capacity after 25,000
cycles
Author : T-A
Score : 81 points
Date : 2025-02-21 18:15 UTC (4 hours ago)
(HTM) web link (techxplore.com)
(TXT) w3m dump (techxplore.com)
| AtlasBarfed wrote:
| In theory, a Li-S chemistry should be able to outperform Lithium
| Ion NCM chemistries by a factor of two or three.
|
| Operating temperature range and cycle endurance were some primary
| barriers, and this seems promising, but ...
|
| "The researchers suggest more work is required to improve the
| energy density and perhaps to find other materials to use for the
| mix to ensure a low-weight battery."
|
| ok, nevermind.
| antisthenes wrote:
| When to comes to batteries, you have to look at multiple factors.
|
| Focusing on just 1, e.g. cycles doesn't give you the whole
| picture.
|
| 1. What is the capacity per $?
|
| 2. What is the capacity per kg?
|
| 3. What is the capacity per unit of volume?
|
| 4. Ease of disposal and recycling
|
| 5. Charge and discharge rates.
|
| 6. Safety.
|
| 7. Viable to produce commercially en masse?
|
| There are just off the top of my head, and not necessarily in
| that order. The priority will vary depending on your use case.
| oakwhiz wrote:
| Exactly. For example the weight of a battery matters very
| little if used in a stationary application such as a BESS/UPS.
| But it's very important for transportation e.g. traction power
| Gibbon1 wrote:
| One shouldn't discount the cost of just mass. Feels to me
| eventually products costs are based on manufacturing
| complexity, material costs, and energy. Material costs
| themselves are often energy per unit mass.
| gpm wrote:
| This is research. You should be focusing on "what's new, and is
| it interesting" not "is the thing they made a good product".
|
| That said, Li-S typically looks good with respect to potential
| cost if mass produced (cheap materials), and density metrics.
| The papers abstract has absurdly good things to say about
| charge rates. All-solid batteries are typically going to be
| very safe. So at a glance this research is at least in a very
| commercializable direction.
| ahartmetz wrote:
| >All-solid batteries are typically going to be very safe
|
| Sulfur melts at 115 degC though, so when it overheats, it's
| not solid anymore. But then, it's apparently not just sulfur,
| but sulfur embedded in some other stuff, so who knows.
| adrian_b wrote:
| Here the sulfur is contained in some kind of borophosphate
| glass, which should have a significantly higher melting
| point.
| cman1444 wrote:
| To add a few other factors:
|
| 1. Performance in hot/cold environment
|
| 2. Safety can be broken down to chemical toxicity, and thermal
| stability (likelihood to catch on fire)
|
| 3. Ability to hold a full charge for extended periods of time
| (self discharge rate)
| cogman10 wrote:
| One of the drawbacks to li-s is that it had terrible cycle
| life. This is interesting/exciting because they've found a
| technique to overcome a major disadvantage to a chemistry that
| ticks a lot of the other checkboxs you've listed.
|
| The question now is manufacturing, is this something you can
| use at scale to make batteries.
| Animats wrote:
| Right. All battery articles, to be taken seriously, need a
| little table with those numbers. There are many battery
| technologies which look good on some of those numbers but are
| so bad on others that the technology is useless.
| metalman wrote:
| this has a chart
|
| https://www.batterypowertips.com/how-could-advances-in-
| solid...
|
| and other variants are commonly used
| antisthenes wrote:
| Oh, and another reason why high cycle count may not even be
| relevant - the battery may become technologically obsolete and
| non-viable to operate _long_ before it reaches anywhere near
| the projected cycle count.
|
| So very high cycle counts (e.g. anything above 4000 cycles ~ 10
| years of use) should be taken with a very large grain of salt
| and may be completely irrelevant for practical uses, unless the
| application calls for multiple daily discharges (if that's the
| case, why not use a supercapacitor?)
| adrian_b wrote:
| There is no doubt about lithium-sulfur batteries being
| excellent and better than existing lithium-based batteries for
| conditions 1, 2, 4 and 7.
|
| Depending on their structure, there may be problems to be
| solved about their safety and the resistance to corrosion of
| their components, which may limit the lifetime to lower values
| than expected from the number of cycles supported by the
| electrodes.
|
| Here the sulfur is contained in some kind of borophosphate
| glass, which should not be easily flammable, so safety or
| corrosion problems are unlikely.
|
| An essential component of this new battery is iodine, which has
| an active redox role, together with lithium and sulfur, iodine
| being an intermediary in the passing of electrons between
| lithium and sulfur. Iodine is a rather rare element.
| Fortunately its extraction from sea water is very cheap, but
| nonetheless the total amount of available iodine is quite
| limited, so hopefully the battery needs much less iodine than
| lithium and sulfur.
| gpm wrote:
| > Fortunately its extraction from sea water is very cheap,
| but nonetheless the total amount of available iodine is quite
| limited,
|
| Huh? I don't know anything about this, but sea water is very
| plentiful so if that's where we get it how can the amount
| available be limited?
| yapyap wrote:
| I hope the better batteries, when they genuinely are deemed to be
| better, are used in phones and stuff instead of using batteries
| that'll go bad in a few years on purpose to drive up sales of new
| phones.
|
| Even people who can deal with the slower speeds after a few years
| of owning a phone get driven crazy by having to charge it often,
| I'd say it's a big driver if not the biggest to buy a new phone.
| hackingonempty wrote:
| We already have longer lasting chemistries, lithium iron
| phosphate. They are also an order of magnitude less likely to
| go into thermal runaway. However, they are seldom used probably
| because they are somewhat less energy dense and consumers
| prioritize size and runtime over battery life and safety. I
| don't think it is a ploy to drive up sales.
| master-lincoln wrote:
| You could also just exchange the battery instead of getting a
| new phone. Of course producers made that more difficult over
| the years. By 2027 mobile phones sold in the EU are mandated to
| have a replaceable battery.
| mrabcx wrote:
| "lithium-ion batteries .. degrade after just 1,000 cycles" If you
| charge your car battery twice a week and complete a full cycle
| then we are still talking about like 9 years to reach 1000
| cycles. If you charge your phone every day, and do a full cycle,
| then we are close to 2.7 years. But you will probably not do a
| full cycle. So, I guess lithium-ion batteries are not really that
| bad.
| hackingonempty wrote:
| Don't forget calendar life. Lithium batteries degrade over time
| even if you do not cycle them. The life of the commonly used
| chemistries is only around 3 years.
| api wrote:
| Degrade to what extent? I have a 12 year old Nissan Leaf
| that's lost maybe 25% of its range. Still absolutely usable
| as a neighborhood car.
| fredrikholm wrote:
| > neighborhood car
|
| Not familiar with that term, what does it mean? Shared
| ride? A car for walking distances?
| globular-toast wrote:
| An electric wheelchair.
| BobaFloutist wrote:
| I think they mean "city car" as opposed to "road trip
| car" or "rural car."
| Cupprum wrote:
| Going to work, groceries and so on, the regular stuff.
|
| If the city was walkable, you would not need such a thing
| as neighborhood car, you could just use a bike, but
| apparently as a society at many places we have decided
| that the cars are the best mode of transportation ever.
| neogodless wrote:
| A 2013 Nissan Leaf should get 60-75 miles of range
| (depending on how much of thebattery you use, as well as
| climate, and other driving conditions). If it got ~80 miles
| new, it would still get 60 miles now. That might be enough
| for someone to make a short commute, though unless they
| have relatively fast charging at home, a 20+ mile commute 5
| days a week might be tough to pull off. But most errands
| would fall well within the existing / remaining range.
| nuancebydefault wrote:
| If it has moved like 250K km then it is impressive.
| zardo wrote:
| I think most testing uses 80% capacity as the cutoff point.
| Largely because that's when the loss in capacity really
| slows down.
| r00fus wrote:
| Explain my 7.5 year old EV with 95% battery health and 65k
| miles driven?
|
| Your 2nd sentence has issues with reality.
| DylanDmitri wrote:
| Some EVs start with capacity "gated off" to limit the depth
| of early cycles and provide a more graceful degradation.
| r00fus wrote:
| But a lifetime of 3y doesn't jive with why my 7 year old
| vehicle is mostly fully functional. Even with 10% over-
| provisioning (amazingly expensive 7y ago), that's only a
| 15% reduction in 7 years.
|
| The statement "The life of the commonly used chemistries
| is only around 3 years" is completely misleading and
| probably inaccurate.
| freedomben wrote:
| I don't know about the 3 years number, but generally
| speaking battery lives are estimates/averages based on
| statistics. If you have a battery that was well cared for
| it will outperform the average. Also sometimes it's just
| dumb luck. One aberration isn't nearly enough data to
| throw out the entire premise
| saidinesh5 wrote:
| It depends on your usage too, along with the exact
| chemistry and form factor of the lithium battery.
|
| A lot of people report lithium batteries swelling up in
| their phones/tablets around 3-4 years of usage.
| mapt wrote:
| Phone batteries are lithium polymer pouch cells, the
| least durable type commonly used. Car cells with lithium
| ion NMC cylindrical cells are much better, and LIFEPO4 in
| turn is several times more durable than that.
|
| You would be wise to insist on an EV with LIFEPO4
| batteries in the sense that calendar lifetimes are more
| likely to be on par with traditional engines.
| kccqzy wrote:
| The explanation is simple. OP said commonly used
| chemistries. That would be something like LCO. Your EV
| battery is probably NMC.
| tecleandor wrote:
| But it could be very interesting for commercial or industrial
| use: commercial vehicles that are constantly driven and
| charged, power reserve batteries, tools...
|
| And I guess that you could make devices with smaller batteries
| and fast charge, with less fear of wearing them early.
| WaltYoder wrote:
| For grid-level solar energy, we will need batteries that cycle
| at least 200 times per year. A system that requires replacing
| batteries every 5 years can't really be described as "renewable
| energy".
| gpm wrote:
| As long as "replace" includes "take the old batteries and
| turn them into raw materials for making new batteries" it
| definitely can.
|
| Typical issues with old batteries are things like dendrite
| growth. There's nothing wrong with the materials that went
| into making the battery, they've just reshaped themselves
| into an unfortunate spiky structure.
| flowerthoughts wrote:
| Note that LiFePO/LFP batteries used in cars and large
| installations are rated for 5,000+ cycles. They really are on
| another level compared to Li-Co phone batteries that top out at
| 1,000.
| nomel wrote:
| Most EV map displayed 0% to 100% to something like physical 5%
| to 95%, or even more extreme, to help.
| happosai wrote:
| Sulfur in mining tailings is huge problem (
| https://en.wikipedia.org/wiki/Acid_mine_drainage ). This one
| reason there is so much research in Li-S batteries. Plenty of
| material innovations have come from people looking at mine
| tailings and wondering if something useful could me made of it.
| rpaddock wrote:
| For 22 years I designed the electronics controls that ran
| Longwall Coal Mining Machines. I've been in many mines.
|
| The problem with extracting things from tailings is that they
| are often contaminated with low levels of Thorium. Extracting
| the other things like Lithium, Sulfur etc, starts to build up
| the quantity of Thorium. Which sounds good if you want to build
| a molten salt Thorium reactor; I understand that China and
| India have prototype to come on line around 2027. Based on
| designs and experimental units that the US did in the ~1950s.
|
| The tailing problem is that the company is how handling Nuclear
| Grade Material which causes the Nuclear Regulatory Commission
| (NRC) to show up at the mine site. No mine wants to deal with
| this paper work, and health ramifications, headache so the
| tailings are not used.
|
| If the profit ratio to headaches would improve things might
| change.
| mapt wrote:
| This seems backwards.
|
| The tailings do not become nuclear waste when we decide to
| use them for something.
| dcrazy wrote:
| Perhaps the problem is that you are either refining away
| the thorium, or refining away as much non-thorium as you
| can. Either way you end up with mostly-thorium, and we know
| that radioactive stuff gets angry in large groups.
| DennisP wrote:
| Thorium does not get seriously angry, because it's not
| fissile. To start up a thorium reactor, you need enough
| plutonium or uranium spitting out neutrons to convert
| plenty of thorium to U233, which is what fissions and
| makes energy.
|
| And if you want an actual bomb, you need that U233
| without any thorium, because the thorium mostly just
| turns to U233 when it absorbs a thermal neutron (i.e.
| slowed down by a moderator like graphite). In a bomb
| you're relying on fast neutrons.
|
| Read enough books/articles on thorium reactors and you'll
| come across a photo of the US thorium stockpile, which is
| a great big stack of pure thorium bricks.
| westmeal wrote:
| Everythings ass backwards when bureaucrats or the military
| get involved.
| mchannon wrote:
| It's not sulfur so much as sulfate.
|
| It doesn't always come from mining. A huge problem with acid
| rock drainage (ARD) showed up when they built a freeway in
| Pennsylvania by merely exposing the rock.
|
| The concept of making batteries out of drainage because both
| contain sulfur is like making socks out of cow manure because
| both contain carbon. There's so much of the latter that you
| could never use it all, but also the ingredient is dirt cheap
| in pure form.
|
| I have a side project that could convert ARD into industrial
| strength sulfuric acid, which is unbelievably difficult to buy
| and transport, despite it being the most common industrial
| chemical in the world after water.
| pfdietz wrote:
| It's sulfides like pyrite that, when exposed to air, are
| oxidized by bacteria to sulfate.
|
| There's an enormous belt of pyrite in Spain that has caused a
| river, the Rio Tinto, to be one of the most acid rivers on
| the planet.
|
| https://en.wikipedia.org/wiki/Rio_Tinto_(river)
| cyanydeez wrote:
| Yes, and it's not just "random" sulfur, it's integral to
| the geologic complexes that miners look for to get the
| minerals they want.
|
| Think of it like the husk of a corn cob, or the cob of your
| corn. It's a byproduct of the very things we're looking for
| in mining.
|
| The only other activity that could get hose minerals is
| indistinguishable from magic.
| mapt wrote:
| I'm not sure the belt of pyrite is best labelled as the
| cause here.
|
| It might have something to do with the inferred activities
| of Rio Tinto, a transnational corporation that is one of
| the largest mining firms in the world.
| mapt wrote:
| Acid rock drainage is currently devastating Arctic streams
| with the melting of pockets of permafrost, which are in
| effect strip mines.
|
| https://youtu.be/Lxfpgqn6NOo?feature=shared
|
| One of the larger sinks for waste sulfur might be
| stratospheric injection for geoengineering, which is looking
| increasingly likely.
| pfdietz wrote:
| Once we stop using fossil fuels, maybe sulfur in mine tailings
| will become a valuable resource. Today, sulfur comes from
| desulfurization of fossil fuels.
| cyanydeez wrote:
| so long living batteries are a _good thing_.
|
| Almost everything humans do requires an extensive life cycle
| analysis.
|
| but you know, lets just cut everything and pretend that'll
| improve our assessments of reality.
| gamblor956 wrote:
| This is big news....if it can be refined into a scalable process
| enabling commercial production.
|
| LI-S batteries have significantly more capacity than commercial
| Li-[x] batteries of the same weight, but the big weakness until
| now has been that they have terrible durability.
| ASalazarMX wrote:
| I'm kinda curios to know if they smell bad because of the
| sulfur. LiPo smells sweet, like bubblegum, when its electrolyte
| leaks. Would a Li-S electrolyte leak smell nice like fireworks,
| or weird like onion/garlic?
| elvircrn wrote:
| ----------------------------------------------------------------
| Dear battery technology claimant,
|
| Thank you for your submission of proposed new revolutionary
| battery technology. Your new technology claims to be superior to
| existing lithium-ion technology and is just around the corner
| from taking over the world. Unfortunately your technology will
| likely fail, because:
|
| [ ] it is impractical to manufacture at scale.
|
| [ ] it will be too expensive for users.
|
| [ ] it suffers from too few recharge cycles.
|
| [ ] it is incapable of delivering current at sufficient levels.
|
| [ ] it lacks thermal stability at low or high temperatures.
|
| [x] it lacks the energy density to make it sufficiently portable.
|
| [ ] it has too short of a lifetime.
|
| [ ] its charge rate is too slow.
|
| [ ] its materials are too toxic.
|
| [ ] it is too likely to catch fire or explode.
|
| [ ] it is too minimal of a step forward for anybody to care.
|
| [ ] this was already done 20 years ago and didn't work then.
|
| [ ] by this time it ships li-ion advances will match it.
|
| [ ] your claims are lies.
|
| ----------------------------------------------------------------
|
| Source: https://news.ycombinator.com/item?id=26633670
| dyauspitr wrote:
| What other boxes does it check because otherwise it's viable
| for home scale uses.
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