• dual_sport_dork 🐧🗡️@lemmy.world
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    7 months ago

    Well, only relatively.

    In order to work batteries need to have a certain amount of instability built in, on a chemical level. Them electrons have to want to jump from one material to a more reactive one; there is literally no other way. There is no such thing as a truly “safe and stable” battery chemistry. Such a battery would be inert, and not able to hold a charge. Even carbon-zinc batteries are technically flammable. I think these guys are stretching the truth a little for the layman, or possibly for the investor.

    Lithium in current lithium-whatever cells is very reactive. Sodium on its own is extremely reactive, even moreso than lithium. Based on the minimal lookup I just did, this company appears to be using an aqueous electrolyte which makes sodium-ion cells a little safer (albeit at the cost of lower energy density, actually) but the notion that a lithium chemistry battery will burn but a sodium chemistry one “won’t” is flat out wrong. Further, shorting a battery pack of either chemistry is not likely to result in a good day.

      • dual_sport_dork 🐧🗡️@lemmy.world
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        7 months ago

        It is definitely that. That’s kind of the point, actually. Sodium is easier to come by than lithium and does not require mining it from unstable parts of the world, nor relying on China.

        • UnderpantsWeevil@lemmy.world
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          7 months ago

          nor relying on China

          The appeal of China is largely in the size of the labor force. Whether this tech is more or less feasible than cobalt and lithium, businesses will still want to exploit the large volume of cheap Chinese labor in order to build them.

        • Wooki@lemmy.world
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          7 months ago

          If you consider Australia unstable, sure, maybe for humans, the animals are fine unless you’re Steve Irwin, just dont go diving with stingrays

    • Dharma Curious (he/him)@slrpnk.net
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      7 months ago

      You who are so wise in the ways of science, can you explain to me if this is safe/will be super dangerous if exposed to water? Doesn’t sodium, like, blow the fuck up when it comes in contact with water?

      • WolfLink@lemmy.ml
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        7 months ago

        Yeah throwing a piece of sodium metal into water will cause a violent reaction. Even touching it with your finger is bad because of the moisture on your skin.

        But sodium chloride (table salt) dissolves in water easily and safely, resulting in an aqueous solution including sodium ions.

      • dual_sport_dork 🐧🗡️@lemmy.world
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        7 months ago

        Well, metallic sodium liberates hydrogen real fast on contact with water, which I guess is tantamount to the same thing.

        Yes. But not to the same level as just dropping a brick of pure sodium in a bathtub. In a battery like this there is not pure lithium/sodium/whatever just sloshing around inside. The sodium is tied up being chemically bonded with whatever the anode and cathode materials are. Only a minority of the available sodium is actually free in the form of ions carrying the charge from cathode to anode.

        Just as with lithium-ion chemistry batteries, it is vital that the cells remain sealed from the outside because the materials inside will indeed react with air, water, and the water in the air. Exposing the innards will cause a rapid exothermic reaction, i.e. it will get very hot and optionally go off bang.

        • Dharma Curious (he/him)@slrpnk.net
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          7 months ago

          Okay, that makes a lot of sense. I was asking because I wondered how viable this would be in boats/ships, outdoor areas, off grid cabins, et cetera. Seems like it’s basically the same thing, then, right? Like, proper battery maintenance and you’re good?

        • soEZ@lemmy.world
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          7 months ago

          These are more fun then lipos… I wounder if u pack a tesla full of these…will it manage to achive escape velocity after a crash? I mean gas cars and lithium batteries right now just turn car into lots fo smoke and flames…but these might really change how we see crashes…

          Edit: I feel like I need to add an /s somewhere…the amout of serious replies to this comment are concerning 🤦

          • Nindelofocho@lemmy.world
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            7 months ago

            That explosion doesent seem much bigger than a firework thats smaller than the battery’s size. With as much as a car weighs and the amount we already do to protect batteries in electric cars i imagine the explosion from these could be easier to manage safely than a lithium fire. I also wonder how harmful the fumes are compared to lithium

            • Gormadt@lemmy.blahaj.zone
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              7 months ago

              Especially considering there’s no fire from a sodium cell, just a quick bang. They definitely seem a lot safer.

              • cybersin@lemm.ee
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                7 months ago

                Yep, less/no fire is very important when creating battery banks with many cells. The probability of single cell failure spreading to adjacent cells is reduced, making a catastrophic failure of the entire bank less likely.

          • cybersin@lemm.ee
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            7 months ago

            LiPo batteries of the same capacity actually have the potential to be much more dangerous than the sodium cell shown here.

            LiPo packs typically use flat, soft walled cells which are far more susceptible to being punctured. In the event of a puncture or overcharge event, high temperature enduring flames are produced, with the severity and duration largely depending on the amount of energy within the cell. LiPo batteries also degrade at a much faster rate (both over time and with charge cycles) and have been known to spontaneously combust in storage while at rest.

            With the sodium battery, the thrust produced by the puncture could have been easily been overcome by properly securing the cell.

    • UnderpantsWeevil@lemmy.world
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      7 months ago

      the notion that a lithium chemistry battery will burn but a sodium chemistry one “won’t” is flat out wrong

      Flinging a brick of sodium into my bathtub to prove you wrong.

    • ✺roguetrick✺@lemmy.world
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      7 months ago

      Doesn’t take into account the reactivity difference with the matrix either. Solid state batteries are in a vitrified matrix essentially, and glass don’t burn. Would make a lithium solid state battery likely safer than this.