Hi all,
I'm trying to make some conventional Li-S electrolyte which requires the addition of LiNO3. This chemical is relatively hydroscopic and even the anhydrous one contains quite a lot water. One thing about LiNO3 is it's a strong oxidizer that has the potential of explosion, so I'm hesitant about using common salt drying method (vacuum oven at high temperature). There's also much in literature indicating how did they make their electrolytes and dry LiNO3. Would anyone who's also doing Li-S study tell me how do you dry your LiNO3 salt?
P.S. This is just a thought about justifying using common vacuum oven method to dry oxidizers like LiNO3. Under vacuum, even know LiNO3 is a stronger oxidizer, but there isn't fuel in the oven that can cause fire. After vacuum heat, I can let the temperature drop to room T first before refill the chamber with air, or refill it with Ar. Does it make sense?
Thank you!
LiNO3 is not that dangerous. Its melt was used by many groups as a reactant for ion-exchange reactions in ceramics without any special precautions. On the the hand, under vacuum it can decompose to LiNO2.
Nitrate salts are often hygroscopic.
Often low melting points and reactivity make these compounds challenging to dry.
To simply account for the quantity of adsorbed water, one can use thermogravimetry (TGA) to determine the amount of excess water in a nominally anhydrous precursor, and adjust your stoichiometry accordingly. Often you will find that this excess water is only in the order of 1-2%.
If a strictly anhydrous precursor is necessary you can use a drying oven around 120 C with a good airflow (fan inside the oven) in a ventilated room (with fume extraction). The nitrate by itself should not be explosive.
Good luck
The commercial LiNO3 salt labeled 'anhydrous' can, in principle, be dried by 120—180 ºC. Not so dry LiNO3 salt can be dryed at 180 ºC for a few days, and/or by fusing under vacuum, preferably more than once. After dried, can be kept in vacuum desiccator.
You may refer to the signalled paper:
F.G. Donnan, B.C. Burt, "XXXV.—The solubilities and transition-points of lithium nitrate and its hydrates", J. Chem. Soc., Trans., Vol. 83, 1903, 335-342.
- Badges
- Science topic
- Similar topics
- Chemistry
- Sulfites
- Inorganic Chemistry
- Inorganic Chemicals
- Salts