Cathode active material, cathode comprising same, and secondary battery

Patent metadata

Field	Value
Publication number	US-11888157-B2
Application number	US-201917263284-A
Country	US
Kind code	B2
Filing date	Jul 26, 2019
Priority date	Jul 27, 2018
Publication date	Jan 30, 2024
Grant date	Jan 30, 2024

Abstract

Provided are a cathode active material, a cathode comprising same, and a secondary battery. The cathode active material contains crystal water and a manganese-based metal oxide and has a first crystal phase having a two-dimensional crystal structure and a second crystal phase having a three-dimensional crystal structure, wherein the three-dimensional crystal structure is formed by the combination of manganese in the manganese-based metal oxide and oxygen in the crystal water.

First claim

The invention claimed is:

1. A cathode active material comprising:
crystal water; and
a manganese-based metal oxide,
wherein the cathode active material includes a first crystal phase having a two-dimensional crystal structure and a second crystal phase having a three-dimensional crystal structure, and
wherein the three-dimensional crystal structure is formed by a combination of manganese in the manganese-based metal oxide and oxygen in the crystal water.

2. The cathode active material of claim 1 , wherein, in a unit lattice of the three-dimensional crystal structure, the manganese fills an octahedral site and a tetrahedral site of the unit lattice.

3. The cathode active material of claim 1 , wherein in a unit lattice of the two-dimensional crystal structure, the manganese fills an octahedral site of the unit lattice.

4. The cathode active material of claim 1 , wherein the second crystal phase has manganese, from which more than 0 and ¼ of manganese filling an octahedral site in the first crystal phase is extracted, filling a tetrahedral site to form a coordination bond with four oxygen atoms.

5. The cathode active material of claim 1 , wherein the crystal water is contained 0.01 mol to 0.5 mol with respect to 1 mol of the manganese-based metal oxide.

6. The cathode active material of claim 1 , wherein the two-dimensional crystal structure includes two or more unit layers including manganese oxide, and at least one metal element which is disposed between two or more unit layers and is selected from the group of metals other than the manganese.

7. The cathode active material of claim 6 , wherein a gap between the unit layers is 3 Å to 6 Å.

8. The cathode active material of claim 6 , wherein at least some of the crystal water is disposed between the two or more unit layers.

9. The cathode active material of claim 1 , wherein the first crystal phase is a stable phase, the second crystal phase is metastable, and the first crystal phase and the second crystal phase have a reversible phase transition relationship.

10. The cathode active material of claim 1 , wherein the cathode active material is represented by Formula 1 below,
Me x MnO 2 ·y H 2 O  [Formula 1]

where Me is at least one metal element selected from the group consisting of an alkali metal element and an alkaline earth metal element, 0.23≤x≤1, and 0.01≤y≤0.5.

11. The cathode active material of claim 10 , wherein the Me is at least one element selected from Li, Na, K, Ca, and Mg.

12. A cathode comprising the cathode active material of claim 1 .

13. A secondary battery comprising a cathode of claim 12 ; an anode; and an electrolyte interposed between the cathode and the anode.

14. The secondary battery of claim 13 , wherein the electrolyte is a non-aqueous electrolyte.

15. The secondary battery of claim 13 , wherein, in the anode, a reversible phase transition between the first crystal phase and the second crystal phase occurs depending on oxidation or reduction of manganese in the manganese-based metal oxide.

16. The secondary battery of claim 13 , wherein, in a charged state of the secondary battery, at least a part of the first crystal phase is phase-transferred to the second crystal phase.

17. The secondary battery of claim 13 , wherein in a discharged state of the secondary battery, at least a part of the second crystal phase is phase-transferred to the first crystal phase.

Assignees

• Univ Korea Res & Bus Found
• Research & Business Found Sungkyunkwan Univ

Inventors

• Yoon Won Sub
• Kang Yong Mook
• Jo Mi Ru
• Yang Junghoon
• Kim Yunok

Classifications

• H01M4/505 Primary

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• H01M2300/0017

  Non-aqueous electrolytes · CPC title