Method for producing lithium carbonate, lithium carbonate produced using the same, and lithium secondary battery comprising positive electrode active material produced using the same

Abstract

To provide a lithium secondary battery having excellent high-temperature life characteristics, lithium carbonate for producing positive electrode active materials contained in such lithium secondary batteries, and a production method for the same.SOLUTION: The present invention relates to a method for producing lithium carbonate, lithium carbonate produced using the same, and a lithium secondary battery comprising a positive electrode active material produced using the same, and more specifically, comprises mixing a lithium nickel-based composite oxide and a coating liquid to form a first mixture, wherein the coating liquid comprises a coating raw material, a precipitant, and a solvent, filtering the first mixture to recover a washing liquid containing 1000 ppm or more of lithium, filtering the washing liquid, mixing and heating the filtered washing liquid and sodium carbonate to form a second mixture, and filtering, washing, and drying the second mixture, wherein the heating is performed at a temperature of 50°C to 80°C.SELECTED DRAWING: Figure 6

Claims

1. Mixing a lithium nickel-based composite oxide and a coating liquid to form a first mixture, the coating liquid including a coating raw material, a precipitant, and a solvent; filtering the first mixture to recover a wash solution having at least 1000 ppm lithium; filtering the cleaning solution; mixing and heating the filtered cleaning solution and sodium carbonate to form a second mixture; filtering, washing, and drying the second mixture; Including, The heating is carried out at a temperature of 50°C to 80°C. How to make lithium carbonate.

2. The lithium nickel-based composite oxide has a nickel (Ni) content of 80 mol% to 100 mol% of metals excluding lithium. The method for producing lithium carbonate according to claim 1.

3. The coating raw material is a cobalt compound; The method for producing lithium carbonate according to claim 1.

4. The cobalt compound includes at least one selected from the group consisting of cobalt nitrate, cobalt sulfate, cobalt oxide, cobalt hydroxide, and cobalt carbonate. The method for producing lithium carbonate according to claim 3.

5. The precipitating agent includes at least one selected from the group consisting of sodium hydroxide, lithium hydroxide, potassium hydroxide, and ammonia; The method for producing lithium carbonate according to claim 1.

6. the cleaning solution contains 3500 ppm to 5000 ppm of lithium; The method for producing lithium carbonate according to claim 1.

7. The concentration of impurities in the cleaning solution is 20 ppm to 40,000 ppm; The method for producing lithium carbonate according to claim 1.

8. The heating is carried out for 30 minutes to 300 minutes. The method for producing lithium carbonate according to claim 1.

9. Produced by the production method according to claim 1, It has a plate box shape, Lithium carbonate.

10. the lithium carbonate has a first width in a horizontal direction defined by a first direction and a second direction intersecting each other, a second width in a vertical direction defined by a third direction intersecting the first direction and the second direction; the first width is greater than the second width; The lithium carbonate of claim 9.

11. the first width is between 3.5 μm and 15 μm; The lithium carbonate of claim 10.

12. the second width is between 0.05 μm and 3 μm; The lithium carbonate of claim 10.

13. The aspect ratio of the lithium carbonate is 10 to 100. The lithium carbonate of claim 9.

14. The purity of the lithium carbonate is 95% to 99.999%. The lithium carbonate of claim 9.

15. In the XRD spectrum of the lithium carbonate using Cu-Kα radiation, the ratio of the maximum intensity of the (002) plane to the maximum intensity of the (110) plane is 1.1 to 2. The lithium carbonate of claim 9.

16. In the XRD spectrum of the lithium carbonate using Cu-Kα radiation, the full width at half maximum of the peak corresponding to the (110) plane is 0.0300 to 0.0500 degrees. The lithium carbonate of claim 9.

17. In an XRD spectrum of the lithium carbonate using Cu-Kα radiation, the full width at half maximum of the peak corresponding to the (002) plane is 0.100 degrees to 0.177 degrees. The lithium carbonate of claim 9.

18. The positive electrode active material is produced by mixing and heat-treating the lithium carbonate and the transition metal-containing compound according to claim 9. Lithium secondary battery.

19. The positive electrode active material includes a lithium-nickel composite oxide having a nickel (Ni) content of 50 mol% to 100 mol% among metals other than lithium.

19. The lithium secondary battery according to claim 18.

20. When charged and discharged 30 times at 1C / 1C at 45°C, the lithium secondary battery has a capacity retention rate of 90% or more.

19. The lithium secondary battery according to claim 18.

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