Secondary battery and electronic device

Patent metadata

Field	Value
Publication number	US-2026005243-A1
Application number	US-202519318472-A
Country	US
Kind code	A1
Filing date	Sep 4, 2025
Priority date	Oct 26, 2020
Publication date	Jan 1, 2026
Grant date	—

Abstract

The secondary battery includes a positive electrode active material which exhibits a broad peak at around 4.55 V in a dQ/dVvsV curve obtained when the charge depth is increased. The secondary battery includes a positive electrode active material which, even when the charge voltage is greater than or equal to 4.6 V and less than or equal to 4.8 V and the charge depth is greater than or equal to 0.8 and less than 0.9, does not have the H1-3 type structure and can maintain a crystal structure where a shift in CoO 2 layers is inhibited. The broad peak at around 4.55 V in the dQ/dVvsV curve indicates that a change in the energy necessary for extraction of lithium at around the voltage is small and a change in the crystal structure is small.

First claim

What is claimed is:

1 . A lithium-ion secondary battery comprising:
a positive electrode comprising a positive electrode active material; and a negative electrode comprising a negative electrode active material, wherein the positive electrode active material comprises a positive electrode active material particle comprising lithium cobalt oxide, magnesium, nickel, and aluminum, wherein the negative electrode active material comprises carbon, wherein, in STEM-EDX linear analysis of the positive electrode active material particle, a peak of concentration of aluminum is located deeper from a surface of the positive electrode active material particle than a peak of concentration of magnesium, wherein the positive electrode active material has a property that an X-ray diffraction pattern of the positive electrode active material has at least a first peak at 2θ of 19.30±0.20° and a second peak at 2θ of 45.55±0.10°, as analyzed by powder X-ray diffraction with a CuKα1 ray in a charged state when charged with a lithium metal counter electrode, and wherein the charged state is obtained after the steps comprising:
a first step of performing four cycles of charge and discharge the positive electrode active material with the lithium metal counter electrode, the charge performed at 25° C. and at 4.7 V, and
a second step of performing charge the positive electrode active material with the lithium metal counter electrode at 25° C. and 4.7 V after the first step.

2 . A lithium-ion secondary battery comprising:
a positive electrode comprising a positive electrode active material; and a negative electrode comprising a negative electrode active material, wherein the positive electrode active material comprises a positive electrode active material particle comprising lithium cobalt oxide, magnesium, nickel, and aluminum, wherein the negative electrode active material comprises carbon, wherein, in STEM-EDX linear analysis of the positive electrode active material particle, a peak of concentration of aluminum is located deeper from a surface of the positive electrode active material particle than a peak of concentration of magnesium, wherein the positive electrode active material has a property that an X-ray diffraction pattern of the positive electrode active material has at least a first peak at 2θ of 19.30±0.20° and a second peak at 2θ of 45.55±0.10°, as analyzed by powder X-ray diffraction with a CuKα1 ray in a charged state when charged with a lithium metal counter electrode, and wherein the charged state is obtained after the steps comprising:
a first step of performing four cycles of charge and discharge the positive electrode active material with the lithium metal counter electrode, the charge performed at 45° C. and at 4.7 V, and
a second step of performing charge the positive electrode active material with the lithium metal counter electrode at 45° C. and 4.7 V after the first step.

3 . A lithium-ion secondary battery comprising:
a positive electrode comprising a positive electrode active material; and a negative electrode comprising a negative electrode active material, wherein the positive electrode active material comprises a positive electrode active material particle comprising lithium cobalt oxide, magnesium, nickel, and aluminum, wherein the negative electrode active material comprises carbon, wherein, in STEM-EDX linear analysis of the positive electrode active material particle, a peak of concentration of aluminum is located deeper from a surface of the positive electrode active material particle than a peak of concentration of magnesium, wherein the positive electrode active material has a property that an X-ray diffraction pattern of the positive electrode active material has at least a first peak at 2θ of 19.30±0.20° and a second peak at 2θ of 45.55±0.10°, as analyzed by powder X-ray diffraction with a CuKα1 ray in a charged state when charged with a lithium metal counter electrode, and wherein the charged state is obtained after the steps comprising:
a first step of performing four cycles of charge and discharge the positive electrode active material with the lithium metal counter electrode, the charge performed at 25° C. and at 4.7 V, and
a second step of performing charge the positive electrode active material with the lithium metal counter electrode at 25° C. and 4.8 V after the first step.

4 . The lithium-ion secondary battery according to claim 1 ,
wherein the positive electrode active material comprises a crystal structure whose space group is R-3m in the charged state.

5 . The lithium-ion secondary battery according to claim 2 ,
wherein the positive electrode active material comprises a crystal structure whose space group is R-3m in the charged state.

6 . The lithium-ion secondary battery according to claim 3 ,
wherein the positive electrode active material comprises a crystal structure whose space group is R-3m in the charged state.

7 . The lithium-ion secondary battery according to claim 1 ,
wherein the positive electrode active material particle comprises titanium.

8 . The lithium-ion secondary battery according to claim 2 ,
wherein the positive electrode active material particle comprises titanium.

9 . The lithium-ion secondary battery according to claim 3 ,
wherein the positive electrode active material particle comprises titanium.

10 . The lithium-ion secondary battery according to claim 1 ,
wherein the positive electrode active material particle comprises fluorine.

11 . The lithium-ion secondary battery according to claim 2 ,
wherein the positive electrode active material particle comprises fluorine.

12 . The lithium-ion secondary battery according to claim 3 ,
wherein the positive electrode active material particle comprises fluorine.

13 . The lithium-ion secondary battery according to claim 1 ,
wherein the lithium-ion secondary battery comprises an electrolyte solution, and wherein the electrolyte solution comprises vinylene carbonate.

14 . The lithium-ion secondary battery according to claim 2 ,
wherein the lithium-ion secondary battery comprises an electrolyte solution, and wherein the electrolyte solution comprises vinylene carbonate.

15 . The lithium-ion secondary battery according to claim 3 ,
wherein the lithium-ion secondary battery comprises an electrolyte solution, and wherein the electrolyte solution comprises vinylene carbonate.

16 . The lithium-ion secondary battery according to claim 13 ,
wherein the electrolyte solution further comprises a dinitrile compound.

17 . The lithium-ion secondary battery according to claim 14 ,
wherein the electrolyte solution further comprises a dinitrile compound.

18 . The lithium-ion secondary battery according to claim 15 ,
wherein the electrolyte solution further comprises a dinitrile compound.

19 . The lithium-ion secondary battery according to claim 16 ,
wherein the dinitrile compound comprises adiponitrile.

20 . The lithium-ion secondary battery according to claim 17 ,
wherein the dinitrile compound comprises adiponitrile.

21 . The lithium-ion secondary battery according to claim 18 ,
wherein the dinitrile compound comprises adiponitrile.

22 . The lithium-ion secondary battery according to claim 16 ,
wherein the dinitrile compound comprises succinonitrile.

23 . The lithium-ion secondary battery according to claim 17 ,
wherein the dinitrile compound com

Assignees

• Semiconductor Energy Lab

Inventors

• Saito Jo
• Momma Yohei
• Fukushima Kunihiro
• Hosoumi Shunsuke
• Tanemura Kazuki
• Kakehata Tetsuya
• Yamazaki Shunpei
• Ohno Toshikazu
• Mikami Mayumi
• Takahashi Tatsuyoshi
• Shimada Kazuya

Classifications

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M2220/30

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

• H01M10/0569

  characterised by the solvents · CPC title