CN-122000316-A - Positive electrode active material and lithium ion secondary battery

Abstract

The purpose of the present invention is to provide a positive electrode active material for a lithium ion secondary battery, which can further improve the discharge capacity, and a lithium ion secondary battery using the positive electrode active material. And also contributes to the energy efficiency. The positive electrode active material of the invention is a cobalt-free positive electrode active material taking lithium nickel manganese composite oxide as a carrier, and granular silicon dioxide is loaded on the surface of the lithium nickel manganese composite oxide.

Inventors

• JI XIAN
• Jin'an Youshu
• MORITA YOSHIYUKI
• YUKI CHIBA
• Sakakura Ichikuang
• NISHIGUCHI KOJI
• Zuo Fangze

Assignees

• 本田技研工业株式会社

Dates

Publication Date

20260508

Application Date

20251031

Priority Date

20241106

Claims (5)

1. 1. A cobalt-free positive electrode active material using a lithium nickel manganese composite oxide as a carrier, And carrying granular silicon dioxide on the surface of the lithium nickel manganese composite oxide.
2. 2. The positive electrode active material according to claim 1, wherein a mass ratio of the mass M 2 of the particulate silica to a total mass M 1 +M 2 of the mass M 1 of the lithium nickel manganese composite oxide and the mass M 2 of the particulate silica, that is, (M 2 /（M 1 +M 2 )) x 100 is more than 0 mass% and 2.0 mass% or less.
3. 3. The positive electrode active material according to claim 1, wherein the particle diameter of the particulate silica is 5nm or more and 300nm or less.
4. 4. The positive electrode active material according to claim 1, wherein the average particle diameter of the lithium nickel manganese composite oxide is 0.25 to 10 μm.
5. 5. A lithium ion secondary battery comprising a positive electrode, a negative electrode and an electrolyte, wherein the positive electrode contains the positive electrode active material according to any one of claims 1 to 4.

Description

Positive electrode active material and lithium ion secondary battery Technical Field The present invention relates to a positive electrode active material and a lithium ion secondary battery. Background In recent years, research and development of secondary batteries contributing to energy efficiency have been conducted. In particular, lithium ion secondary batteries are increasingly important as power sources for Electric Vehicles (EVs), hybrid Electric Vehicles (HEVs), and the like. The positive electrode active material has been attracting attention as an important component for determining the capacity of a lithium ion secondary battery, and development thereof has been advancing. As a positive electrode active material used in a lithium ion secondary battery, for example, cobalt-free lithium nickel manganese composite oxides with low resource risk have been reported (for example, patent document 1 and patent document 2). Prior art literature Patent literature Patent document 1 Japanese patent No. 7446486 Patent document 2 Japanese patent application laid-open No. 2024-58307 Disclosure of Invention Technical problem to be solved by the invention Lithium ion secondary batteries using cobalt-free lithium nickel manganese composite oxides as positive electrode active materials have a smaller discharge capacity than nickel and cobalt-based materials used in the prior art, and there is room for improvement. The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a positive electrode active material capable of further improving the discharge capacity of a lithium ion secondary battery, and a lithium ion secondary battery using the positive electrode active material. In addition, the energy efficiency is also improved. Technical scheme for solving technical problems In order to achieve the above object, the present invention provides the following technical solutions. [1] A cobalt-free positive electrode active material using lithium nickel manganese composite oxide as carrier, And carrying granular silicon dioxide on the surface of the lithium nickel manganese composite oxide. [1] The positive electrode active material is prepared by supporting granular silica on the surface of a lithium nickel manganese composite oxide. This promotes the decomposition of lithium carbonate as the high-resistance layer, and can reduce the resistance of the lithium nickel manganese composite oxide. Therefore, the discharge capacity of the lithium ion secondary battery using the positive electrode active material can be further improved. Therefore, the number of required batteries can be reduced, contributing to cost reduction. That is, energy efficiency can be improved. [2] The positive electrode active material according to [1], wherein a mass ratio ((M 2/（M1+M2)). Times.100) of the mass (M 2) of the particulate silica to a total (M 1+M2) of the mass (M 1) of the lithium nickel manganese composite oxide and the mass (M 2) of the particulate silica is more than 0 mass% and 2.0 mass% or less. [2] In the positive electrode active material, the mass ratio ((M 2/（M1+M2)) ×100) of the mass (M 2) of the particulate silica to the total (M 1+M2) of the mass (M 1) of the lithium nickel manganese composite oxide and the mass (M 2) of the particulate silica satisfies a specific numerical range. Therefore, the resistance of the lithium nickel manganese composite oxide is further reduced, and the discharge capacity of the lithium ion secondary battery using the positive electrode active material can be further improved. Therefore, the cycle characteristics can be further improved, and the energy efficiency can be further improved. [3] The positive electrode active material according to [1] or [2], wherein the particle diameter of the particulate silica is 5nm or more and 300nm or less. [3] In the positive electrode active material, the particle diameter of the particulate silica satisfies a specific numerical range. Therefore, the resistance of the lithium nickel manganese composite oxide is further reduced, and the discharge capacity of the lithium ion secondary battery using the positive electrode active material can be further improved. Therefore, the cycle characteristics can be further improved, and the energy efficiency can be further improved. [4] The positive electrode active material according to any one of [1] to [3], wherein the average particle diameter of the lithium nickel manganese composite oxide is 0.25 to 10 μm. [4] The average particle diameter of the lithium nickel manganese composite oxide of the positive electrode active material satisfies a specific numerical range. Therefore, the productivity of the positive electrode active material can be further improved, and the electrochemical characteristics of the lithium ion secondary battery using the positive electrode active material can be further improved. Therefore, the cycle characteristics can be