Method for isolating lithium precursor and system for isolating lithium precursor
A method for isolating a lithium precursor according to an embodiment of the present disclosure includes preparing a preliminary precursor mixture including a preliminary lithium precursor and a preliminary transition metal precursor, mixing the preliminary precursor mixture and a precipitation liquid in a reactor to form a precursor mixture, and injecting a non-reactive gas into the precursor mixture. Accordingly, the lithium precursor can be isolated with high yield and high efficiency.
1. A method for isolating a lithium precursor, comprising:
preparing a preliminary precursor mixture including a preliminary lithium precursor and a preliminary transition metal precursor;
mixing the preliminary precursor mixture and a precipitation liquid in a reactor to form a precursor mixture; and
injecting a non-reactive gas into the precursor mixture,
wherein injecting the non-reactive gas comprises reducing a linear velocity of the non-reactive gas at an upper portion top of the reactor.
2. The method according to claim 1 , wherein the reactor is a fluidized bed reactor.
3. The method according to claim 1 , wherein preparing the preliminary precursor mixture comprises performing a reductive reaction of a cathode active material collected from a lithium secondary battery.
4. The method according to claim 3 , wherein the reductive reaction is performed before forming the precursor mixture in the reactor.
5. The method according to claim 1 , wherein the preliminary lithium precursor comprises lithium hydroxide.
6. The method according to claim 5 , wherein the preliminary lithium precursor further comprises lithium oxide or lithium carbonate.
7. The method of claim 6 , wherein forming the precursor mixture comprises selectively dissolving lithium hydroxide in the precipitation liquid.
8. The method of claim 1 , wherein the precipitation liquid comprises water.
9. The method of claim 8 , wherein the precipitation liquid further comprises dimethyl carbonate or diethyl carbonate.
10. The method according to claim 1 , wherein a mass of the precipitation liquid in the precursor mixture is 2 to 20 times a mass of the preliminary lithium precursor.
11. The method according to claim 1 , wherein the precursor mixture comprises a slurry or a solution containing the preliminary precursor mixture.
12. The method according to claim 1 , wherein injecting the non-reactive gas comprises a pulse injection of the non-reactive gas.
13. The method according to claim 1 , wherein a solubility of the non-reactive gas in the precipitation liquid is 1.5 g/L or less.
14. The method according to claim 1 , wherein the non-reactive gas includes at least one selected from the group consisting of nitrogen, neon, argon, krypton and xenon.
15. The method according to claim 1 , wherein the non-reactive gas is injected into a lower portion of the reactor.
16. The method according to claim 1 , wherein reducing the linear velocity of the non-reactive gas comprises reducing the linear velocity of the non-reactive gas to 0.1 to 3 cm/s.
17. The method according to claim 1 , wherein the upper portion of the reactor includes an expansion unit having an expanded diameter or width.
18. The method according to claim 1 , wherein forming the precursor mixture and injecting the non-reactive gas are repeatedly performed in a plurality of cycles.
19. A system for isolating a lithium precursor, comprising:
a reactor body into which a lithium precursor is introduced;
a precipitation liquid injection unit for injecting a precipitation liquid into the reactor body;
a gas injection unit for injecting a non-reactive gas into a lower portion of the reactor body, wherein the gas injection unit is configured for reducing a linear velocity of the non-reactive gas at an upper portion top of the reactor; and
an expansion unit extending from an upper portion of the reactor body and having an expanded diameter or width.