• 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.

    • 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.

    • 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.

    • Zink@programming.dev
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      7 months ago

      There is no such thing as a truly “safe and stable” battery chemistry.

      Is it even possible to have energy storage of any kind that is truly safe and stable? Some are better than others, of course.

      • laverabe@lemmy.world
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        7 months ago

        On a small scale yeah. The sun heats rocks and they’re able to store heat for up to an hour or so. Cats can attest to that.

        Same with large bodies of water; the ocean, lakes, pools, etc.

        • Zink@programming.dev
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          7 months ago

          I guess in my head I was implying that it was energy humans store for other humans to use at grid scale. When I said "of any kind” I guess that’s not what I meant, lol.

          So in my line of thinking, you’re right about e.g. using the sun to heat a rock. But if we use the sun to heat something for electricity generation, or we heat some medium for energy storage, I bet that will be pretty potent.

          Besides, past the small scale into the smallEST scale, it’s all just energy anyway, man. 😎

      • tal@lemmy.today
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        7 months ago

        Is it even possible to have energy storage of any kind that is truly safe and stable? Some are better than others, of course.

        considers

        Kinetic energy of a body in orbit, I suppose. Like, you want to accelerate the Moon, you get a bigger orbit. We pull energy out of it via tidal generators, and in theory, we could speed its orbit up, increase its altitude.

        I mean, it could theoretically smack into something, but it’s not gonna hit the Earth very readily, and the speed of an object that isn’t in Earth orbit, like an asteroid or something that hasn’t been captured by Earth’s gravitational field, is probably more of a factor in a collision than the speed of something that is.

        At a smaller scale, I expect that thermal energy storage can be pretty safe, as long as you keep it within bounds. Like, if you wanted to insulate a lake and crank its temperature up or down ten degrees, probably not a lot that it could do even if the insulation was penetrated. The rate of energy release is gonna be bounded by convection.

        • Zink@programming.dev
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          7 months ago

          The orbital one sounds interesting. That’s a lot of energy, and it could do a lot of damage, but it seems very stable if left untouched.

          My gut suspicion is that with something more safe/stable, you would also be dealing with a low quality/potency source and/or low efficiency.

      • 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.

        • 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