MIXED CONDUCTOR, METHOD OF PREPARING THE MIXED CONDUCTOR, AND CATHODE, LITHIUM-AIR BATTERY AND ELECTROCHEMICAL DEVICE EACH INCLUDING THE MIXED CONDUCTOR

• US 20200136148A1
• Filed: 10/21/2019
• Published: 04/30/2020
• Est. Priority Date: 10/24/2018
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ma, Sangbok, Kwon, Hyukjae, Lee, Hyunpyo, Seo, Donghwa, Im, Dongmin
• Granted Patent: US 11,424,456 B2
• Time in Patent Office: Days
• CPC Class Codes: C01G 37/00 Compounds of chromium
• CPC Class Codes: C01G 45/1228 of the type [MnO2]n- , e.g. LiMnO2, Li[MxMn1-x]O2
• CPC Class Codes: C01G 51/42 containing alkali metals, e.g. LiCoO2
• CPC Class Codes: C01G 51/50 of the type [MnO2]n- , e.g. Li(CoxMn1-x)O2, Li(MyCoxMn1-x-y)O2
• CPC Class Codes: C01G 53/42 containing alkali metals, e.g. LiNiO2
• CPC Class Codes: C01G 53/50 of the type [MnO2]n- , e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
• CPC Class Codes: C01P 2002/20 Two-dimensional structures
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/74 by peak-intensities or a ratio thereof only
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: H01B 1/08 oxides
• CPC Class Codes: H01G 11/46 Metal oxides
• CPC Class Codes: H01M 12/02 Details of electrodes H01M4/00; of non-active parts H01M50/00
• CPC Class Codes: H01M 12/08 composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
• CPC Class Codes: H01M 2004/8689 Positive electrodes
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 2300/0071 Oxides
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/8673 Electrically conductive fillers
• CPC Class Codes: H01M 4/9016 Oxides, hydroxides or oxygenated metallic salts
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries

Abstract

A mixed conductor, a method of preparing the same, and a cathode, a lithium-air battery, and an electrochemical device each including the mixed conductor. The mixed conductor is represented by Formula 1 and having electronic conductivity and ionic conductivity:

Li_xMO_2-δ  Formula 1

wherein, in Formula 1, M is a Group 4 element, a Group 5 element, a Group 6 element, a Group 7 element, a Group 8 element, a Group 10 element, a Group 11 element, a Group 12 element, or a combination thereof, and 0<x<1 and 0≤δ≤1 are satisfied.

Claims

1. A mixed conductor represented by Formula 1 and having electronic conductivity and ionic conductivity:

Li_xMO_2-δ

 

 

Formula 1

wherein, in Formula 1, M is a Group 4 element, a Group 5 element, a Group 6 element, a Group 7 element, a Group 8 element, a Group 10 element, a Group 11 element, a Group 12 element, or a combination thereof, and 0<

x<

1 and 0≤

δ

≤

1 are satisfied.

2. The mixed conductor of claim 1, wherein M is cobalt, nickel, iron, manganese, vanadium, titanium, chromium, copper, zinc, or a combination thereof.

3. The mixed conductor of claim 1, wherein, in Formula 1, x is from about 0.3 to about 0.5.

4. The mixed conductor of claim 1, wherein the mixed conductor comprises a phase having a layered crystal structure.

5. The mixed conductor of claim 4, wherein the mixed conductor comprises a layer of M-centered oxygen octahedra.

6. The mixed conductor of claim 1, wherein the mixed conductor is a compound represented by Formula 2:

Li_xM¹_aM²_bM³_1-a-bO_2-δ

 

 

Formula 2

wherein, in Formula 2, M¹ is Ni, Co, Mn, or a combination thereof,

M² and M³ are each independently a Group 4 element, a Group 5 element, a Group 8 element, a Group 11 element, a Group 12 element, or a combination thereof, and 0<

x<

1, 0<

a≤

1, 0≤

b <

1, and 0≤

δ

≤

1 are satisfied.

7. The mixed conductor of claim 6, wherein M² and M³ are each independently iron, vanadium, titanium, chromium, copper, zinc, or a combination thereof.

8. The mixed conductor of claim 6, wherein, in Formula 2, a is 1, b is 0, and M¹ has a mixed valence state and comprises metals having a plurality of a different oxidation numbers.

9. The mixed conductor of claim 1, wherein the mixed conductor is Li_xCo_aO_2-δ

, Li_xCo_aNi_1-aO_2-δ

, Li_xCo_aNi_bMn_1-a-bO_2-δ

, Li_xNi_aO_2-δ

, Li_xMn_aO_2-δ

, Li_xCr_aO_2-δ

, Li_xCo_aMn_bO_2-δ

, Li_xNi_aMn_bO_2-δ

, Li_xCr_aMn_bO_2-δ

, or a combination thereof, and

wherein, in each of the foregoing mixed conductors, each x is independently 0<

x<

1, each a is independently 0<

a≤

1, each b is independently 0≤

b<

1, and each δ

is independently 0≤

δ

≤

1.

10. The mixed conductor of claim 1, wherein, in Formula 1, δ

is 0.

11. The mixed conductor of claim 1, wherein the mixed conductor is Li_0.5CoO_2-δ

, Li_0.5CO_0.5Ni_0.5O_2-δ

, Li_0.5NiO_2-δ

, Li_0.5MnO_2-δ

, Li_0.5CrO_2-δ

, Li_0.5Co_0.5Mn_0.5O_2-δ

, Li_0.5Ni_0.5Mn_0.5O_2-δ

, Li_0.5Cr_0.5Mn_0.5O_2-δ

, Li_0.4CoO_2-δ

, Li_0.4Co_0.5Ni_0.5O_2-δ

, Li_0.4NiO_2-δ

, Li_0.4MnO_2-δ

, Li_0.4CrO_2-δ

, Li_0.4Co_0.5Mn_0.5O_2-δ

, Li_0.4ni_0.5Mn_0.5O_2-δ

, Li_0.4Cr_0.5Mn_0.5O_2-δ

, Li_0.3CoO_2-δ

, Li_0.3Co_0.5Ni_0.5O_2-δ

, Li_0.3NiO_2-δ

, Li_0.3MnO_2-δ

, Li_0.3CrO_2-δ

, Li_0.3Co_0.5Mn_0.5O₂O_2-δ

, Li_0.3Ni_0.5Mn_0.5O_2-δ

, Li_0.3 Cr_0.5Mn_0.5O_2-δ

, Li_0.5Co_0.4Ni_0.6O_2-δ

, Li_0.5Co_0.4Mn_0.6O_2-δ

, Li_0.5Ni_0.4Mn_0.6O_2-δ

, Li_0.5Cr_0.4Mn_0.6O_2-δ

, Li_0.5Co_0.3Ni_0.7O_2-δ

, Li_0.3Co_0.3Mn_0.7O_2-δ

, Li_0.5Ni_0.3Mn_0.7O_2-δ

, Li_0.5Cr_0.3Mn_0.7O_2-δ

, Li_0.5Co_0.2Ni_0.8O_2-δ

, Li_0.5Ni_0.8Mn_0.2O_2-δ

, Li_0.5Co_0.1Ni_0.9O_2-δ

, Li_0.5Ni_0.9Mn_0.1O_2-δ

, Li_0.5Co_0.6Ni_0.4O_2-δ

, Li_0.5Co_0.6Mn_0.4O_2-δ

, Li_0.5Ni_0.6Mn_0.4O_2-δ

, Li_0.5Cr_0.6Mn_0.4O_2-δ

, or a combination thereof, and 0≤

δ

≤

1 is satisfied.

12. The mixed conductor of claim 1, wherein an electronic conductivity of the mixed conductor is greater than an ionic conductivity thereof.

13. The mixed conductor of claim 1, wherein the mixed conductor has an electronic conductivity greater than 4.0×

10<sup>−

9</sup> Siemens per centimeter at 25°

C.

14. The mixed conductor of claim 1, wherein the mixed conductor has an ionic conductivity of 1.0×

10<sup>−

9</sup> Siemens per centimeter or greater at 25°

C.

15. The mixed conductor of claim 1, wherein an X-ray diffraction spectrum of the mixed conductor includes a first peak at a diffraction angle of about 65°

2θ and

a second peak at 67°

2θ

, when analyzed using Cu Kα

radiation.

16. The mixed conductor of claim 15, wherein a maximum of the first peak is located in a range of about 65°

2θ

to 66°

2θ

, and

a maximum of the second peak is located in a range of about 66°

2θ

to about 67°

2θ

.

17. The mixed conductor of claim 15, wherein a height of the second peak is in a range of about 30% to about 50% of a height of the first peak.

18. A method of preparing the mixed conductor of claim 1, the method comprising:

mixing a lithium compound, an M-containing compound, and a solvent to obtain a mixture;

first thermally treating the mixture to obtain a first thermal treatment product;

pulverizing the first thermal treatment product to obtain a pulverized product; and

second thermally treating the pulverized product to prepare the mixed conductor of claim 1, wherein M in Formula 1 is a Group 4 element, a Group 5 element, a Group 6 element, a Group 7 element, a Group 8 element, a Group 10 element, a Group 11 element, a Group 12 element, or a combination thereof.

19. The method of claim 18, wherein the second thermally treating comprises thermally treating at a temperature which is greater than a temperature of the first thermally treating.

20. The method of claim 18, wherein the first thermally treating comprises treating at a temperature of about 400°

C. to about 900°

C.

21. The method of claim 18, wherein the second thermally treating comprises treating at a temperature of about 400°

C. to about 1,000°

C.

22. The method of claim 18, wherein the lithium compound is lithium oxide, lithium carbonate, lithium chloride, lithium sulfide, lithium nitrate, lithium phosphate, lithium hydroxide, or a combination thereof.

23. The method of claim 18, wherein the M-containing compound is an M-containing oxide, an M-containing carbonate, an M-containing chloride, an M-containing phosphate, an M-containing hydroxide, an M-containing nitrate, an M-containing hydroxide, or a combination thereof.

24. A cathode comprising the mixed conductor of claim 1, wherein the cathode is configured to use oxygen as a cathode active material.

25. The cathode of claim 24, wherein the mixed conductor is neither oxidized nor reduced when in contact with lithium metal at a voltage of about 2 volts to about 4 volts with respect to lithium metal.

26. The cathode of claim 24, wherein the mixed conductor has an electronic conductivity greater than 4.0×

10<sup>−

9</sup> Siemens per centimeter at 25°

C., and an ionic conductivity of about 1.0×

10<sup>−

9</sup> Siemens per centimeter or greater at 25°

C.

27. A lithium-air battery comprising:

the cathode of claim 24;

an anode comprising lithium; and

an electrolyte between the cathode and the anode.

28. The lithium-air battery of claim 27, wherein the electrolyte comprises a solid electrolyte.

29. The lithium-air battery of claim 27, wherein the electrolyte comprises a mixed conductor represented by Formula 1 and having electronic conductivity and ionic conductivity:

Li_xMO_2-δ

 

 

Formula 1

wherein, in Formula 1, M is a Group 4 element, a Group 5 element, a Group 6 element, a Group 7 element, a Group 8 element, a Group 10 element, a Group 11 element, a Group 12 element, or a combination thereof, and 0<

x<

1 and 0≤

δ

≤

1 are satisfied.

30. An electrochemical device comprising the mixed conductor of claim 1.

31. The electrochemical device of claim 30, wherein the electrochemical device is a battery, an accumulator, a supercapacitor, a fuel cell, a sensor, or an electrochromic device.