Positive electrode active material, method for manufacturing the positive electrode active material, and lithium-ion battery

Patent metadata

Field	Value
Publication number	US-2025372637-A1
Application number	US-202318876275-A
Country	US
Kind code	A1
Filing date	Jun 13, 2023
Priority date	Jun 22, 2022
Publication date	Dec 4, 2025
Grant date	—

Abstract

A positive electrode active material with both high capacity and safety is provided. The secondary battery includes a positive electrode. The positive electrode includes a positive electrode active material. The positive electrode active material includes lithium cobalt oxide containing magnesium, nickel, and aluminum. When the positive electrode is analyzed by powder X-ray diffraction using CuKα1 as a radiation source at a charge depth greater than or equal to 0.8, the positive electrode active material has diffraction peaks at 2θ of 19.30±0.20° and 2θ of 45.55±0.10°. The positive electrode active material includes a first region having a surface parallel to a (001) plane and a second region having a surface parallel to a plane intersecting with the (001). A nickel concentration in the first region is higher than a nickel concentration in the second region.

First claim

1 - 3 . (canceled)

4 . A secondary battery comprising:
a positive electrode comprising a positive electrode active material and a negative electrode, wherein the positive electrode active material comprises lithium nickel cobalt oxide, magnesium, aluminum, and fluorine, wherein in the positive electrode active material, an atomic ratio of nickel in the sum of an atomic ratio of cobalt and the atomic ratio of nickel Ni/(Co+Ni) is greater than 0.005 and less than 0.05, and wherein when the positive electrode active material is subjected to XRD analysis, a crystallite size is greater than or equal to 420 nm and less than or equal to 550 nm.

5 . The secondary battery according to claim 4 ,
wherein, when a lithium metal is used for a counter electrode and charging is performed at 25° C. until a charge voltage reaches 4.6 V, diffraction peaks are exhibited at 2θ of 19.30±0.20° and 2θ of 45.55±0.10°.

6 . The secondary battery according to claim 4 ,
wherein in the positive electrode active material, a ratio of the atomic ratio of cobalt to the atomic ratio of nickel satisfies Co:Ni=99:1 or a neighborhood thereof.

7 . (canceled)

8 . A secondary battery comprising a positive electrode comprising a positive electrode active material and a negative electrode,
wherein the positive electrode active material comprises lithium, cobalt, nickel, oxygen, and an additive element, and wherein when the positive electrode is used as a positive electrode of a test battery comprising a counter electrode formed of a lithium metal, and as a test, CCCV charging with an upper limit voltage of 4.6 V and CC discharging with a lower limit voltage of 2.5 V are repeated 50 times at 25° C., a value of a discharge capacity measured in a 50th cycle satisfies higher than or equal to 98% and lower than 100% of a maximum value of a discharge capacity in 50 cycles.

9 . The secondary battery according to claim 8 ,
wherein when the positive electrode is used as a positive electrode of a test battery comprising a counter electrode formed of a lithium metal, and as a test, CCCV charging with an upper limit voltage of 4.6 V and CC discharging with a lower limit voltage of 2.5 V are repeated 50 times at 45° C., a value of a discharge capacity measured in a 50th cycle is greater than or equal to 190 mAh/g.

10 . (canceled)

11 . The secondary battery according to claim 8 ,
wherein the additive element is one or more selected from magnesium, aluminum, and fluorine.

12 - 13 . (canceled)

14 . A secondary battery comprising:
a positive electrode comprising a positive electrode active material and a negative electrode, wherein the positive electrode active material comprises lithium cobalt oxide comprising magnesium, nickel, and aluminum, wherein in a state where a test battery comprises the positive electrode and a counter electrode formed of lithium and the test battery is charged to 4.6 V, when the positive electrode is analyzed by powder X-ray diffraction using CuKα 1 as a radiation source, the positive electrode active material has diffraction peaks at 2θ of 19.30±0.20° and 2θ of 45.55±0.10°, wherein the positive electrode active material comprises a first region comprising a surface parallel to a (001) plane and a second region comprising a surface parallel to a plane other than the (001) plane, and wherein a nickel concentration in the first region is higher than a nickel concentration in the second region.

15 . The secondary battery according to claim 14 ,
wherein the nickel concentration in the first region is higher than or equal to 0.7 atomic % and lower than or equal to 2 atomic %, and wherein the nickel concentration in the second region is higher than or equal to 0.3 atomic % and lower than or equal to 1 atomic %.

16 . The secondary battery according to claim 14 ,
wherein the positive electrode active material further comprises fluorine.

17 . The secondary battery according to claim 14 ,
wherein the positive electrode further comprises a fibrous conductive material.

18 . The secondary battery according to claim 14 ,
wherein the negative electrode comprises graphite.

19 . An electronic device comprising the secondary battery described in claim 14 .

20 . A vehicle comprising the secondary battery described in claim 14 .

21 - 33 . (canceled)

34 . The secondary battery according to claim 8 ,
wherein the value of a discharge capacity measured in a 50th cycle is greater than or equal to 190 mAh/g.

Assignees

• Semiconductor Energy Lab

Inventors

• Yamazaki Shunpei
• Yoshitani Yusuke
• Hirahara Takashi
• Miyairi Noriko
• Nakamura Toshihiro
• Sasaki Kousuke
• Momma Yohei
• Miyata Kikuo

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M4/36

  Selection of substances as active materials, active masses, active liquids · CPC title