Positive electrode active material for potassium secondary battery and potassium secondary battery containing same

Patent metadata

Field	Value
Publication number	US-11075402-B2
Application number	US-201816310849-A
Country	US
Kind code	B2
Filing date	Mar 7, 2018
Priority date	Mar 10, 2017
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

The present invention relates to a positive electrode active material for a potassium secondary battery, the positive electrode active material according to the present invention is a crystalline material comprising: K; a transition metal; P; and O, and comprises, as a main image, an image indicating a diffraction peak having a relative intensity of 5% or more in a range of Bragg angles (2θ) of a X-ray diffraction pattern of 14.7° to 15.7°, 22.1° to 23.1°, 25.5° to 26.5°, and 29.7° to 30.8°, when the relative intensity of the diffraction peak having the highest intensity is taken as 100% in the powder X-ray diffraction pattern of the material.

First claim

The invention claimed is:

1. A positive electrode active material for a potassium secondary battery, which is a crystalline material comprising K, a transition metal, P, and O, the material comprising:
as a main phase, a phase showing a diffraction peak having a relative intensity of 5% or more in a range of Bragg angles (2θ) of an X-ray diffraction pattern of 14.7° to 15.7°, 22.1° to 23.1°, 25.5° to 26.5°, and 29.7° to 30.8° when a relative intensity of a diffraction peak having the strongest intensity is taken as 100% in the powder X-ray diffraction pattern of the material,
wherein the crystalline material has a composition of Formula 1,
[Formula 1]
(K 1-a M1 a )(M2 1-b M3 b ) P c O d
wherein, M1 is one or more among alkali metal elements other than K, M2 and M3 are one or more among transition metal elements, and 0≤a≤0.2, 0≤b≤0.7, 1.8≤c≤2.2, and 6.8≤d≤7.2, and
wherein the crystalline material includes one or more selected from Li, Na, Rb, Al, La, Gd, and Lu.

2. The positive electrode active material of claim 1 , wherein the transition metal includes one or more selected from V, Ti, Fe, Cr, Mo, Mn, Co, and Ni.

3. The positive electrode active material of claim 1 , wherein in the crystalline material, a phase transition to a monoclinic crystal structure and a triclinic crystal structure is dynamically performed in a charge and discharge process.

4. The positive electrode active material of claim 1 , wherein the crystalline material has a monoclinic crystal structure in a charged state and a triclinic crystal structure in a discharged state.

5. The positive electrode active material of claim 1 , wherein the crystalline material has a space group P2 1 /c in a charged state and a space group P-1 in a discharged state.

6. A potassium secondary battery comprising:
a positive electrode;
a negative electrode; and
an electrolyte,
wherein the positive electrode includes a positive electrode active material including: K; a transition metal; P; and O, and the positive electrode active material includes, as a main phase, a phase showing a diffraction peak having a relative intensity of 5% or more in a range of Bragg angles (2θ) of an X-ray diffraction pattern of 14.7° to 15.7°, 22.1° to 23.1°, 25.5° to 26.5°, and 29.7° to 30.8° when a relative intensity of a diffraction peak having the strongest intensity is taken as 100% in the powder X-ray diffraction pattern,
wherein the crystalline material has a composition of Formula 1,
[Formula 1]
(K 1-a M1 a )(M2 1-b M3 b )P c O d
wherein, M1 is one or more among alkali metal elements other than K, M2 and M3 are one or more among transition metal elements, and 0≤a≤0.2, 0≤b≤0.7, 1.8≤c≤2.2, and 6.8≤d≤7.2, and
wherein the crystalline material includes one or more selected from Li, Na, Rb, Al, La, Gd, and Lu.

7. The potassium secondary battery of claim 6 , wherein the transition metal includes one or more selected from V, Ti, Fe, Cr, Mo, Mn, Co, and Ni.

8. The potassium secondary battery of claim 6 , wherein the main phase includes a crystalline material in which a phase transition to a monoclinic crystal structure and a triclinic crystal structure is dynamically performed in a charge and discharge process.

9. The potassium secondary battery of claim 8 , wherein the crystalline material has the monoclinic crystal structure in a charged state and the triclinic crystal structure in a discharged state.

10. The potassium secondary battery of claim 8 , wherein the crystalline material has a space group P2 1 /c in a charged state and a space group P-1 in a discharged state.

Assignees

• Industry Academia Cooperation Group Of Sejong Univ

Inventors

• Sohn Kee-Sun
• Park Un-Bea

Classifications

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/1397

  of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• C01P2002/74

  by peak-intensities or a ratio thereof only · CPC title