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Power Science

Could Zinc Batteries Replace Lithium-Ion Batteries on the Power Grid? (sciencemag.org) 120

Slashdot reader sciencehabit shares Science magazine's look at efforts to transform zinc batteries "from small, throwaway cells often used in hearing aids into rechargeable behemoths that could be attached to the power grid, storing solar or wind power for nighttime or when the wind is calm." With startups proliferating and lab studies coming thick and fast, "Zinc batteries are a very hot field," says Chunsheng Wang, a battery expert at the University of Maryland, College Park. Lithium-ion batteries — giant versions of those found in electric vehicles — are the current front-runners for storing renewable energy, but their components can be expensive. Zinc batteries are easier on the wallet and the planet — and lab experiments are now pointing to ways around their primary drawback: They can't be recharged over and over for decades.

For power storage, "Lithium-ion is the 800-pound gorilla," says Michael Burz, CEO of EnZinc, a zinc battery startup. But lithium, a relatively rare metal that's only mined in a handful of countries, is too scarce and expensive to back up the world's utility grids. (It's also in demand from automakers for electric vehicles.) Lithium-ion batteries also typically use a flammable liquid electrolyte. That means megawatt-scale batteries must have pricey cooling and fire-suppression technology. "We need an alternative to lithium," says Debra Rolison, who heads advanced electrochemical materials research at the Naval Research Laboratory. Enter zinc, a silvery, nontoxic, cheap, abundant metal. Nonrechargeable zinc batteries have been on the market for decades. More recently, some zinc rechargeables have also been commercialized, but they tend to have limited energy storage capacity. Another technology — zinc flow cell batteries — is also making strides. But it requires more complex valves, pumps, and tanks to operate. So, researchers are now working to improve another variety, zinc-air cells...

Advances are injecting new hope that rechargeable zinc-air batteries will one day be able to take on lithium. Because of the low cost of their materials, grid-scale zinc-air batteries could cost $100 per kilowatt-hour, less than half the cost of today's cheapest lithium-ion versions. "There is a lot of promise here," Burz says. But researchers still need to scale up their production from small button cells and cellphone-size pouches to shipping container-size systems, all while maintaining their performance, a process that will likely take years.

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Could Zinc Batteries Replace Lithium-Ion Batteries on the Power Grid?

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  • by mnemotronic ( 586021 ) <mnemotronic@noSpaM.gmail.com> on Saturday May 29, 2021 @04:38PM (#61434904) Homepage Journal
    Why wouldn't lead-acid batteries for suitable for non-mobile applications? Cheapness counts.
    • by PPH ( 736903 )

      This.

      They are heavy. But who cares for utility applications? And they are toxic. But utility/industrial uses are easy to regulate. Just don't throw them away in the public dump.

      • by ShanghaiBill ( 739463 ) on Saturday May 29, 2021 @05:54PM (#61435088)

        Lead batteries are inefficient (RTE of 70% vs over 90% for lithium), not good for deep discharge, and have relatively high self-discharge rates.

        Mining lead is a filthy process.

        The main advantage of lead batteries is a very high current. That is important for crank-starting an engine, but not important for grid storage.

        There are better alternatives.

        • There is quite a bit of lead that can be reclaimed and recycled. And it's better to have it tied up in a useful product that has its environmental lifecycle managed than to let it sit around where it can leech into surface water.

          Alternative chemistries still based on lead are theoretically possible, so I wouldn't give up on lead as one possible component of future battery technology.

          • by vivian ( 156520 )

            The construction of a traditional deep storage lead acid battery is pretty simple - basically just plates of lead in acid. Starter batteries are a bit more complex because they are optimised to be light as possible with high surface area grid formed plates that increase the current they can deliver but reduce their lifespan for deep storage, but I think deep cycle batteries are basically just flat slabs of lead. If it was possible to have closed loop recycling for the lead plates, they could be recycled on

            • A large marina and other large industrial users could potentially recycle on site, I think that's an interesting thought. I'm not sure the return on capital investment would be worthwhile for the equipment and staff though.

              Right now the batteries are shipped out on truck to a recyclers that drains and crushes the cells, sorts the lead from the plastic, and ships the lead out to a battery manufacturer. If you ever buy a car battery and it says "Made in China" (and don't live in China) then you've broke this

        • Self discharge doesn't really matter when when your storage time is a couple days at most.

          And lead recycles well, as does the acid.

          Mining anything is a filthy process. I used to work in mining, mineral processing to be exact. I know how nasty it can be.

          But I do agree with the conclusion, there are better choices for grid storage than lead acid batteries.

          • Perhaps the biggest advantage of lead acid batteries is that as you say they recycle well. Literally every part of them is recycled except the labels, and batteries have had less and less labeling over the years to the point where it's quite minimal now. (And sadly, often the lettering wipes away with strong degreaser... fail, fail. Nothing else takes off that battery terminal protectant.)

            They also respond well to abuse. If you don't leave them deeply discharged for long they often can be recharged without

        • Lead batteries are inefficient (RTE of 70% vs over 90% for lithium), not good for deep discharge, and have relatively high self-discharge rates.

          Mining lead is a filthy process.

          The main advantage of lead batteries is a very high current. That is important for crank-starting an engine, but not important for grid storage.

          There are better alternatives.

          Lead Acid Batteries do not perform well in sub-freezing temperatures.

      • by AmiMoJo ( 196126 )

        There are better options like sodium batteries for non mobile grid scale stuff.

        The issue is that it's hard to compete with lithium because there is so much demand for it. Lots of factories, lots of opportunities to use less than perfect cells that aren't automotive grade but perfectly fine for grid scale or home storage batteries.

        The headline figure for lithium cells is not the one you need to compare to. There price paid for the lower grade cells is a faction of that.

    • The cycle life is much too short compared to the needs of grid electricity storage, and refurbishing is environmentally toxic and costly. Their cost isn't going down and their performance doesn't seem to be going up very much being already an optimized and mature technology.

      They're a known technology---they'd be prevalent already in grid scale applications if they were feasible, but it looks like they aren't. You do see off-grid individuals with these, but you'll find that the operators need to take grea

      • I have seen 50-80 year old central office lead-acid batteries still in use, after over 1,000 full discharge cycles. They aren’t economical— a roughly 1MW plant occupies about 20,000 square feet, and there are three full-time technicians to manage the battery plant, and they have poor round-trip efficiency relative to Lithium but they still work and aren’t worth replacing. (A 1kW cell is about the size of an oil drum.)

    • They're not that good.

      Now, sodium batteries on the other hand...

      Thing is they're not pie in the sky tech. They exist and the largest grid connected battery is a sodium sulphur batter. The trouble is they don't have Tesla's reality distortion field so Tesla gets the credit even though it's makes no sense.

      The nice thing about them is sodium is cheap and plentiful and doesn't need mining, and sulphur is a widely available byproduct.

    • by crunchygranola ( 1954152 ) on Saturday May 29, 2021 @06:32PM (#61435194)

      Going by this study from 2019 comparing grid storage technology [energy.gov], and using projected total project cost in 2025 ($/kWh) as the benchmark, it seems that of the 10 storage technologies compared (6 of them batteries), the cheapest is CAES (compressed air storage) at $105, pumped hydro at $165, and Li-Ion at $362. Among batteries the #2 is zinc-hybrid $433, and lead acid at $464. Sodium-sulfur, sodum metal halide and redox flow all have about the same cost $650-669.

      But lead acid is really a non-starter due to its short cycle life (900 cycles vs 3500-10000 for the others) unless a re-manufacturing process is included in the cost. Doable - design a plant so that the batteries are regularly renewed by remanufacture, but it raises the operating cost substantially.

      It does not consider all possible batteries - there are different versions of zinc batteries for example, some promising ones are too early in development to characterize (sodium ion), etc.

      Pumped hydro is already a widely deployed storage technology (93-98% of all U.S. storage was PH), but its capacity for ultimate expansion is limited due to geographic constraints (not enough places to with the right profile). CAES is interesting, and may have greater ultimate potential than hydro, but can't be put everywhere, but I expect it to be in the mix as an important player.

      Though lithium is ahead of zinc in this comparison, its lead is small. Known reserves of lithium have been growing rapidly due to higher market price, and more interest in exploration, and at some price point (and with extraction technology advances) it will be obtainable from the ocean and the supply will be effectively unbounded. This raises the price of the Li-Ion solution, but far less than you probably think. The cost of the battery itself is only half the final cost, and lithium is only a fraction of the battery cost. A 1 KWh battery uses about 1.2 kg of lithium carbonate, with a market price of $10, less than 3% of the cost of the final grid battery installation cost.

      • Re: (Score:3, Informative)

        by mamba-mamba ( 445365 )

        CAES is thermodynamically inefficient compared to batteries. Of course, I am ignoring the energy required to make the battery. But compressing air, then letting it cool, then extracting energy from the compressed (and now cool) air always loses heat to the environment. I am surprised it can maintain cost effectiveness given this energy deficit.

        • by drinkypoo ( 153816 ) <drink@hyperlogos.org> on Sunday May 30, 2021 @09:12AM (#61436492) Homepage Journal

          I wonder if you could get back some of that energy with a stirling engine with its hot side being created by the compressed air, and the cold side being created by the expanding air on the other side of a restriction. It might be viable because of the steep thermal differential. Obviously you're never going to break even, but if you could make the process less inefficient it would be a win. And you'd be able to feed the power back into the compressor system, using it immediately.

      • The one thing I really like about compressed air, is the near zero environmental footprint, especially if there is an accident and a blow-out.
      • I wonder where flywheel tech flts into all of this. It isn't the best for mobile applications, but for UPS and other uses, it might be an alternative to batteries, and magnetic bearings mean that wear is not an issue.

    • In a grid storage application they would be lucky to last a year. They don't like deep discharge.

      Since weight isn't really an issue, nickel metal hydride should be looked at again. Power to volume ratio was close to lithium, but they did weigh more.

      Zinc supplies are not all that unlimited, geology concentrates it fairly well, but there are not that many deposits. And a lot is lost as galvanizing and sacrificial anodes.

      Sodium sulfur has been figured out after decades of work, and a really large one is online

      • by djinn6 ( 1868030 )

        Zinc supplies are not all that unlimited, geology concentrates it fairly well, but there are not that many deposits. And a lot is lost as galvanizing and sacrificial anodes.

        Worldwide lithium deposits are estimated at 20 million tons [wikipedia.org]. Meanwhile, the world produced 13 million tons of zinc [wikipedia.org] in one year. Just how many batteries do you think we need?

        • Now that is the question, isn't it. Clearly Texas needed quite a few. So ERCOT's full load in cold weather for a week is the upper bound just for Texas. In the upper Midwest you would be looking at two weeks of no wind and heavy overcast at full winter heating load.

          And you would need to scale both of those up by whatever fossils fuel or nuclear plants you shut down, or hydroelectric dams you tear out to appease the environmentalists.

          • by djinn6 ( 1868030 )

            It was a rhetorical question. But since you can't be bothered to do some basic back-of-the-envelope calculations, let me do that instead.

            Total annual lithium production is about 75,000 tons [wikipedia.org]. That gets turned into 455 GWh of batteries [spglobal.com]. If we were to turn all 13 million tons of zinc mined annually into batteries of similar power capacity to that of lithium, we would have 82.5 TWh of new batteries every year. This is more than the US's installed battery storage capacity [renewablesnow.com] by a factor of 66.

            Forget the manufacturi

    • For longevity and when weight isn't a problem then Nickel/Iron are a good choice.

      • For longevity and when weight isn't a problem then Nickel/Iron are a good choice.

        AND if efficiency - in terms of percentage of the power you put in that you get back out - isn't a big deal. Charge-discharge efficiency is under 65% (so you lose a third of the energy right off the bat) and self-discharge is another 20-30% per month.

        On the other hand, a renewable energy system MUST have SOMEWHAT more generation than consumption or there will be times when it fails to provide power. If you have more than 1 1/

    • They are not cheaper over the life of the battery. Even though lithium ion and LFP batteries are more expensive than lead, they also have longer cycle lives, so they are cheaper for high-cycle applications. Flooded lead batteries require constant maintenance (checking the water level) which probably makes them totally unsuitable for grid scale applications.

      Lead acid battery types exist which do not require water to be added. Gel cell and AGM types. But they are a bit more expensive than flooded batteries.

      Le

      • A number of recycling centers for Lithium are just coming online. In a couple of years most end-of-life batteries will be recyclable.
        • A number of recycling centers for Lithium are just coming online.

          That's because electric cars have both driven up the price of lithium and are just now starting to produce large amounts of big dead batteries for recycling. The combination of raw material availability and price for recovered product made profitable recycling operations possible.

    • For the same reason many outdated technologies are not suitable for non-mobile applications. If you're going to back something other than Lithium that actually exists then a vanadium redox battery would be the next best thing. That said they aren't maintenance free as 2 pumps are required. However their capacity is easily expanded (add more electrolyte), the electrolyte is non-toxic and non-flammable, they can deep discharge, they can remain fully discharged without damage, they operate over incredible temp

    • Why wouldn't lead-acid batteries for suitable for non-mobile applications? Cheapness counts.

      Lead acid certainly could be used on the grid, but they can't 'replace' existing lithium ion as most grid batteries today serve ancillary support functions (frequency and voltage support), requiring super fast response times measured in milliseconds. Few lower cost battery technologies have that kind of response capability, even some Lithium Ion battery designs are better than others.

  • Pigs might grow wings.

    Panda to your FOMO before its too late!

    Spivs need your money now!

  • Lithium will serve us well for many generations to fill laptop and phone batteries but the rate at which they're producing these batteries to run cars and whole houses off them (Here in Ireland Ginlong hybrid grid-tie inverters with PylonTech LifePo4 batteries are common) there will be a lithium squeeze at some point.

    When you think about it 100-120 years ago when Petrol engines were starting to get common there was no talk of running out of oil, the concept of there being a day that they'd have used it all up would have been unfathomable to your average top hat-wearer walking to the theatre. Yet electric cars are only starting to get common now and there's already talk of material shortages (if it's not Lithium then it's some other unusual metal they're stuffing into those cars).

    There was talk 10+ years ago of supercapacitors made out of graphine that could store many jiggawatts, what became of them? In '08 it seemed like the energy storage problem would be solved very soon but it hasn't really. You can buy a LifePo4 battery now that will last a good few thousand half-cycles now but they're still not really recyclable
    • Comment removed (Score:5, Interesting)

      by account_deleted ( 4530225 ) on Saturday May 29, 2021 @05:03PM (#61434970)
      Comment removed based on user account deletion
      • by sfcat ( 872532 )

        The main issue has been a relatively short shelf life, but reportedly recent developments allow for batteries with at around 10,000 charging cycles.

        Citation needed. The best I've seen is 500 charging cycles.

        • Comment removed based on user account deletion
          • Re: (Score:3, Informative)

            by vivian ( 156520 )

            I found this article that claims 90% charge retention after 250,000 cycles for Aluminium grapene battery, claiming 120mAh/g and very high power density of 400A/g but no mention of Clemson University. They also claim their battery is flexible, withstanding up to 10,000 folds.

            https://advances.sciencemag.or... [sciencemag.org]

        • Citation needed. The best I've seen is 500 charging cycles.

          Anecdote: My spouse bought a Tesla in 2015. She drives it nearly every day and charges it every night.

          Her EV still has 95% of its original range.

          365 * 6 = 2190

          The 500 cycles may mean a 100% charge followed by a 0% discharge. But that is battery abuse. Nobody does that in real life.

          • by sfcat ( 872532 )

            The 500 cycles may mean a 100% charge followed by a 0% discharge. But that is battery abuse. Nobody does that in real life.

            That's exactly what you do with a grid scale battery and that's the use case.

            • That's exactly what you do with a grid scale battery and that's the use case.

              Telsa recommends their PowerWall be charged to 80%. Most other grid-backup lithium battery providers recommend the same.

              A discharge to 0% would rarely happen. Only when the weather is cloudy and becalmed for several consecutive days over a wide geographic area. Even then, much of the shortage could be managed with flex-pricing rather than damaging the batteries.

            • No, you don't. Economically it would be an idiotic thing to do that unless you absolutely have to (e.g., in emergencies and such).
        • by ras ( 84108 )

          Standord's Al battery was tested to 7,500 cycles and showed no degradation [scientificamerican.com]. I suspect that had too low energy density to be useful, but now a mob in Australia had refined it to have triple the energy density and tested to 2,000 with no degradation [graphenemg.com].

          These Al ion graphite batters also support absurdly high charge / discharge rates, so if the grid storage thing doesn't work cost wise out they still might be useful as service station storage. They can easily pump out 75kWh in 15 minutes, and with the high cyc

      • For all aluminum's faults,

        What are the problems with aluminum?

      • by jabuzz ( 182671 )

        You are aware that lithium is the third most abundant element in the Universe?

  • For grid storage Lithium-Ion batteries are far to expensive and their weight advantages are irrelevant for stationary use. So the competitor is lead acid which doesn't use rare elements in appreciable amounts.

    • by Guspaz ( 556486 ) on Saturday May 29, 2021 @05:10PM (#61435000)

      If theyâ(TM)re too expensive, then why are there already a bunch of lithium-ion grid scale storage facilities out there, some of them highly profitable? If lead acid was practical, youâ(TM)d see it being used for grid scale storage instead. You donâ(TM)t.

    • The best competitor is sodium sulphur which is why there are a bunch already connected to the grid, one even larger than the biggest lithium battery.

    • Re: (Score:2, Informative)

      Lithium-Ion batteries do not use rare elements either.

    • It is actually the cheapest battery option, among battery technologies that are ready for installation today.

  • We saw in Australia that large batteries are capable of keeping the grid going in case of a loss of a large gigawatt sized steam plant, in that case it was coal but it could have just as easily been a nuclear power plant. The battery was part of a project to even out the intermittent nature of a large wind project, and perhaps it served well there but the ability of batteries to manage the variations in load to the steady supply of steam power was also proven.

    Utility scale batteries are not going to save s

    • by mbkennel ( 97636 ) on Saturday May 29, 2021 @05:50PM (#61435074)

      Except solar is the price leader in almost all new power developments, your cost ideas are 5 years or more out of date. The optimists who said "have patience, scalable solar will get inexpensive" were correct and the grumps were wrong.

      Unfortunately nuclear costs are going up and up without scale. If solar + storage becomes notably cheaper than nuclear for 24 hour power then it will be hard to convince significant use outside high latitudes.

      I think we'll need significant nuclear for deep decarbonization but right now all the momentum and economics is on the side of solar. No it won't suddenly turn off in 30 years, efficiency goes down. Any fossil plants also need maintenance and refurbishment over their lifetime, plus what will be continually increasing fuel costs and (justified) environmental restrictions .

    • by spitzak ( 4019 )

      Whoa, there seems to be a shift in the Nuclear fanatics. Used to be that everything was TERRIBLE about batteries. So awful, horrible, bad, bad, bad, BAD batteries!!!! Nobody would put a bettery in a car, it was nonsense. Read the hundreds and hundreds of posts from these guys in previous Slashdots.

      The problem of course is that batteries make solar and wind and even hydro power that are intermittent work, so they are bad news, even (as this poster points out) they could also help back up nuclear plants start

      • When was everything terrible about batteries?

        Hydro is not intermittent. At least not inherently so like wind and solar. Hydroelectric dams will vary output because it is easier and cheaper to vary output at a dam than at any kind of steam plant. Steam being coal, combined cycle natural gas, nuclear, and maybe some kinds of geothermal. Hydro will have only so much water it can dispense of depending on the climate and geography. There's typically more water in the spring from rains and melting snow. Win

      • Whoa, there seems to be a shift in the Nuclear fanatics. Used to be that everything was TERRIBLE about batteries. So awful, horrible, bad, bad, bad, BAD batteries!!!! Nobody would put a bettery in a car, it was nonsense

        They will trot out any bullshit argument to attack solar with, it does not matter how batshit crazy it is, any club they can use makes them happier than a pig in shit. (No matter what kind of animal they are... it's all shit.)

        They saw us using the argument "batteries make solar viable" in response to their "the sun only shines during the day" argument, so they changed tack to "batteries will kill solar" for absolutely no reason other than that it's the opposite of what we were saying. There's no evidence to

    • Solar power has a capacity factor of maybe 25% or at best 30%, and is not providing power during the early morning and late evening peaks.
      You still have not grasped what a CF is.
      A standard solar panel aiming directly south, and being tilted so that the sun at 12:00 hits it perpendicular: has 100% efficiency. Ooops.

      Same way you can aim it to early morning, then you have your efficiency peak at 7:00 if you want so, or you aim it at late evening, then you have your efficiency peak at 19:00, if you want so.

      And

      • Peak solar output at 7:00 and 19:00? That's a neat trick when the sun doesn't rise until 7:21 and sets at 16:35. That is unless your peak for the day is zero watts. Oops.

        I suggest to get a damn dictionary and look up what CF means.

        I suggest you copy it from the dictionary for me and post it here so that there is no confusion between us. My dictionary might be different than yours. It appears my dictionary says CF is short for cystic fibrosis.

        Rooftop solar for an household of 4 people with battery, producing roughly 85% of the consumption over one year, costs about $15,000. It is payed of after roughly 12 -14 years. So yes: in 30 years the same installation will probably cost $3000. You would be an idiot if you do not replace your solar plant with a new solar plant. Unless you can get a < $3000 mini nuclear plant for your basement.

        WTF does a residential solar PV and battery system have to do with a utility building a solar array and batteries? Next a

        • Peak solar output at 7:00 and 19:00? That's a neat trick when the sun doesn't rise until 7:21 and sets at 16:35. That is unless your peak for the day is zero watts. Oops.
          Depends on time of the year, and your location.

          Now you finally prooved: you are an complete idiot.
          I live 6month a year in thailand: sun rises 6:00 and sets 18:00, more or less the whole year around.
          Oops.

          WTF does a residential solar PV and battery system have to do with a utility building a solar array and batteries?
          Nothing. But that is how

          • Depends on time of the year, and your location.

            I live 6month a year in thailand: sun rises 6:00 and sets 18:00, more or less the whole year around.

            CF: ratio between produced energy versus maximum possible production during a year. Simple. And you fail to grasp why CFs are completely irrelevant when you compare power plants/power plant technology.

            If CF is an average over a year then CF does not depend on the time of year. The sunrise and sun set times vary on time of year but anywhere on the Earth that will average out to 12 hours per day. Actually slightly more because of the sun not being a point source of light, diffraction over the horizon, and other effects, but generally about 12 hours any place on Earth averaged over a year. So, if CF is an average over the year then the CF does not depend on the day.

            You are not making sense. You are cont

            • You are not making sense. You are contradicting yourself. CF cannot both depend on the day if it is an average over a year.
              I never said that CF depends on the day.

              That is your stupid conclusion from not grasping what a CF is.

              • Why do you care if I grasp what CF means if you say it doesn't matter?

                I don't care how you reply. I'm just seeing if you will reply.

    • The entire premise of your post about the Hornsdale Power Reserve is incorrect. The battery does very little to even out the intermittent nature of wind energy. What it was for is grid wide frequency regulation to prevent cascading failures due to a sudden load change in a way that is far more resilient to wide swings than classical frequency regulation services.

      It's success is not wind + battery storage. It's success is many gas power plants + battery frequency regulation for the few seconds it takes to br

  • I thought that sulfur was the next big thing in power grid batteries - IIRC, the issue was cathode swelling but that there were solutions "just around the corner".

    Is this the case of Zinc being the latest shiny (no pun intended) thing for power grid batteries, actually a very promising approach or just one of the many chemistries being investigated to replace Lithium based batteries?

    • Nothing happened to them. They're here and the largest grid connected battery is a sodium sulphur one. However those cells have no reality distortion field so you know they vanished.

    • Sodium Sulphur has its place, but the economics are tough relative to Lithium Ion. Sodium-nickel was going strong for a while, but that seems to have been starved for funding lately.

    • There is a ton of research going into all kinds of batteries. Even (what I would consider) exotic batteries like Nickel-Iron that have to be kept at extremely high temps. There are a LOT of different chemical batteries that are out there.

      Lithium has a HUGE research lead due to it's widespread use. But all battery types are having lots of money poured into R&D. IMO it's most probable that Lithium will win simply by staying ahead of the others. Most people simply don't realize how much Lithium batteries h

  • by Brane2 ( 608748 )

    .

  • So what is the resistance to Edison batteries, 100 year old technology, free of copyright burden ?
    Good for 50 years, maybe even 100 years, proven dependable technology.
    Made for grid connection, not pretty, not super light weight or hyper efficient, a real work horse

    https://www.noonco.com/edison/... [noonco.com]

    • Edison is amazing tough battery with over 20 year lifespan in heavy use situations that used to be in forklifts and railroad applications, but 65 percent charge-discharge efficiency compared to best li-ion with over 99 percent.

      Of course a a "normal" zinc-air has only 3 years life and about 50 percent efficiency, so I'd suppose these people have a solution for that.

      • Of course a a "normal" zinc-air has only 3 years life and about 50 percent efficiency, so I'd suppose these people have a solution for that.

        They do have a solution, because these aren't zinc-air. They're zinc-carbon, similar to lithium ion cells.

        Of particular interest is the one recently announced, which uses graphene for the carbon cathode. In particular, graphene with holes in it, slightly bigger than a zinc ion, mostly in three-layer stacks. It goes from discharged to fully charged in under a minute,

  • "...We need an alternative to lithium", the third most common element in the Universe. Oh God we're fucked.
    • "...We need an alternative to lithium", the third most common element in the Universe. Oh God we're fucked.

      Lithium is number 3 in terms of atomic number, hydrogen and helium being numbers 1 and 2. But it is much less abundant in the universe than higher numbered elements such as carbon, oxygen, silicon and iron. My Wikipedia trawl indicates that Li, Be, and B are all much less abundant than one might expect from their low atomic number, because they are consumed in fusion reactions in stars.

      Abundance on Earth is another matter. For example, helium is very common in the universe, but very rare on Earth, because i

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