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I would like to make a small decorative object out of lithium, and keep it in an ordinary household (indoors) atmosphere.

The making itself aside, what can I do to protect it long-term from reacting with the atmospheric water and gases? Is there something that could react with it to form a protective outer layer, like oxides do on some other metals? Is it perhaps possible to electroplate it with Mg or Al? Are there other solutions?
To be clear, I don't want to just keep it submerged in oil; I want it to stand on a shelf and hopefully even get handled occasionally by curious hands.

I have no access to advanced equipment or supplies - I'm only armed with a high-school level of chemical understanding, access to ordinary hardware/paint shops, and patience.


I do understand that the question is unusual and has little broad practical utility, but it's still a proper chemistry problem to which I would like to see a proper chemistry solution (or an exhaustive explanation why a search for a solution is futile). Please don't answer along the lines of "your idea is stupid and you should feel stupid".

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    $\begingroup$ I’m downvoting because it ‘lacks research effort’. $\endgroup$ – Jan Dec 12 '16 at 1:14
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    $\begingroup$ Rust-oleum (tm). Spray lacquer. $\endgroup$ – Joseph Hirsch Dec 12 '16 at 1:39
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    $\begingroup$ @Jan, at my level of education, it was already a research effort to find out how readily it reacts with atmospheric N₂ and CO₂ (after hydroxidation). Nobody makes physical things out of Li, so there isn't really any practical information out there, which is why I'm turning to a better-educated site for help. This now sounds like, in order to ask the question "right", I pretty much need to go and keep learning more about chemistry until I know the answer anyway. $\endgroup$ – hemflit Dec 12 '16 at 6:51
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    $\begingroup$ Keep it in a jar under mineral oil. $\endgroup$ – Klaus-Dieter Warzecha Dec 12 '16 at 12:21
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    $\begingroup$ ‘Like all alkali metals, lithium is highly reactive and flammable. For this reason, it is typically stored in mineral oil.’ The sentence is practically screaming ‘your idea is a bad idea.’ To quote you: ‘Nobody makes physical things out of Li’ — yes, for a reason. $\endgroup$ – Jan Dec 12 '16 at 22:23
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Interesting question!(Though personally I've no idea why you want to make a decorative article out of lithium, but I guess it's best not ask)

You did consider using the process we know as electroplating; yes, it's one of the common, commercial methods of 'passivating' (rendering inert) a lot of metals that are prone to corrosion, like iron for example (Galvanization). However electroplating is something that could never work out with lithium, here's why...

enter image description here

(The above example, courtesy Google Images, suggests the use of copper as the electroplating metal, but since I can't seem to find a more generalized diagram so we'll just go with this)

A quick crash course on the set-up for electroplating:

Your cathode is the metal to be electroplated, while your anode is the metal (copper here) that is used to electroplate whatever you've hooked up as the cathode. Both the anode and cathode are immersed in an aqueous solution of a salt of the metal used as the anode (here, it's copper sulfate).

Clear with that? Good, now here's the catch...

You need to put lithium in an aqueous solution, that is, a solution that uses water as the solvent. In your question you voice concerns over lithium's reactivity towards stuff you typically come across in your surroundings (oxygen and carbon dioxide in the air, moisture/humidity, etc), so I take it that you are well aware of what happens when you dump a large, fresh piece of lithium in water...

enter image description here

So yeah, don't even think about electroplating this.

The making itself aside, what can I do to protect it long-term from reacting with the atmospheric water and gases?

Well, there are a couple of other methods you could use:

1) Coating it in wax.

Coating the lithium in a thin, uniform layer of wax (candle wax, beeswax, furniture wax or any sort of wax that you can easily get your hands on, and remains a solid at room temperatures) would do a pretty decent job of protecting lithium from your ordinary household environment. It shields the metal from both atmospheric gases and moisture. Heck you could even dump the whole thing in water and it wouldn't go off in your face. But evenly coating a "decorative object" made out of lithium with wax while still being able to see the object clearly under the wax will be a bit tricky...even more so, if this "decoration" of yours has any really intricate patterns.

This is where we move on to the next method,

2) Immersing it in a jar full of mineral/paraffin oil

This is far simpler than coating the thing in wax. Get an airtight, transparent jar, fill it all the way to the brim with mineral oil, slowly immerse the object in the jar so you don't trap any air bubbles, screw on the lid tightly and there you have it! True, a major 'disadvantage' here, is that you can't take the object in your hands and examine it closer as and when you wish (which wasn't the case in the waxing method), but maybe a shiny lithium decoration floating around in a jar might make up for this aesthetically.

Which of the two methods you use, is entirely at your discretion, however, a word of caution:

Lithium metal is a fire risk! Do handle it with care. Have necessary safety arrangements in place.

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Industrially, this has been done by coating with Parylene.

The Rubber and Plastics Age, Volume 46 says:

Parylene coated lithium metal granules on the left exhibit no reaction with water on which they float

and New linear polymers says:

Encapsulation of reactive chemicals in thin parylene C coatings provides protection. Parylene-coated lithium metal granules at left exhibit no reaction with water on which they float Unprotected granules at right react instantly and violently with water.

However, I don't know on what timescale this protection lasts. As others are saying, lithium metal is an extreme fire hazard. What if the coating is scratched or peels? Be careful!

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I would like to make a small decorative object out of lithium, and keep it in an ordinary household (indoors) atmosphere.

You’re trying to open up a really big can of worms. First, let’s start with the making part. The good thing about lithium is that it is soft enough that you can cut it with your average kitchen knife. But that’s about the end of the advantages.

You’ve already read that it reacts readily with atmospheric carbon dioxide, nitrogen and moisture in the air. Hence why you’re asking about some protective coating. But all the difficulties you have with lithium’s reactivity are present and worse when you’re trying to make it. Repeatedly, you will be cutting new edges, adding new blank surfaces that will come into contact with air and moisture for the first time. There will be constant reactions going on.

Let’s assume you somehow managed to handle that. Another sentence of your’s:

I want it to stand on a shelf and hopefully even get handled occasionally by curious hands.

Please don’t let it get handled by curious hands! For one, you should never handle alkaline metals with bare hands (see above their reactivity). For two, any protective coating you may apply to the lithium would get rubbed off given time and curious hands. That would access the underlying lithium metal and all the reactivity problems start again. And when would that happen? Yes, exactly when the curious hand is handling it. Worst case would be spontaneous combustion in somebody’s hand (but admittedly that’s not as likely with lithium as with other alkaline metals).

So if it must stand on the shelf … well … it’s your shelf … But keep a strict ‘do not touch!’ policy for everybody’s safety. (Note that I am not recommending the shelf either.)

I have no access to advanced equipment or supplies

Considering everything, this should be the final straw of your idea. I mean, you also mention:

Nobody makes physical things out of Li

Yes, because it is dangerous, difficult to handle and there are much better solutions out there. Sometimes when nobody does something, it is because nobody came up with the (potentially great) idea yet. Most of the times when nobody does something, it is because there is some very great risk associated with it that is clearly visible to most people. Creating a sculpture out of lithium metal falls into the second category.

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    $\begingroup$ I'm flagging this NAA :P $\endgroup$ – Martin - マーチン Dec 27 '16 at 13:26
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    $\begingroup$ @Martin-マーチン Wow, you got me. I was sure that this was going to be ortho’s comment xD $\endgroup$ – Jan Dec 27 '16 at 15:31
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You could put it inside of a glass vial / melt glass around it under inert atmosphere. Then you can a) see it and it is b) protected from oxidation. Though I don't know how to achieve that with household techniques...

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  • $\begingroup$ OP might want to watch this video before exposing lithium to molten glass youtube.com/watch?v=cFGejaYqM-c ! $\endgroup$ – DavePhD Dec 24 '16 at 4:11
  • $\begingroup$ Yeah well its the question if this will also happen under inert atmosphere. @DavePhD That putting very hot oxides on lithium could turn to be dangerous is of course clear, I don't know if the oxidation of the lithium by the glass as shown in the video will also happen under inert atmosphere and less intense heating. In any way, you can melt a vial around the lithium and in fact that is commonly done with the all of the alkali metals (including e.g. Cs which is much more reactive) to provide specimen for inorganic chemistry classes. $\endgroup$ – logical x 2 Dec 26 '16 at 12:45
  • $\begingroup$ The video specifically says the lithium is taking oxygen from the glass itself $\endgroup$ – DavePhD Dec 26 '16 at 14:25
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    $\begingroup$ @DavePhD Yes, but they a) use a mixture of crushed glass and lithium shavings not normal glass around lithium which greatly enhances the surface area for the reaction b) heat with a bunsen burner c) don't exclude oxygen. I would expect that nothing happens when just melt glass gently around the lithium. And creating a vial will always be possible as then you don't apply the heat onto the lithium metal. Just look it up, evacuated glass vials may be prepared for all kinds of reactive materials including all alkali metals. $\endgroup$ – logical x 2 Dec 26 '16 at 15:20

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