Battery pack and electric device

Patent metadata

Field	Value
Publication number	US-12002960-B2
Application number	US-202318383542-A
Country	US
Kind code	B2
Filing date	Oct 25, 2023
Priority date	Jun 2, 2022
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

A battery pack and an electric device including the battery pack. The battery pack includes a battery pack container and first, second and third battery cells accommodated in different regions of the battery pack container, the first, second and third battery cells each has a first and a second discharge voltage plateau, an average discharge voltage of the first discharge voltage plateau is higher than an average discharge voltage of the second discharge voltage plateau, and the first, second and third battery cells have different proportions of the discharge capacity corresponding to the second discharge voltage plateau.

First claim

The invention claimed is:

1. A battery pack, comprising a battery pack container and battery cells accommodated in the battery pack container, wherein,
an interior space of the battery pack container comprises a first region, a second region and a third region, first battery cells are arranged in the first region, second battery cells are arranged in the second region, third battery cells are arranged in the third region, the second battery cells are arranged surrounding the first battery cells, and the third battery cells are arranged surrounding the second battery cells, wherein,
the first battery cells, the second battery cells and the third battery cells each has a first discharge voltage plateau and a second discharge voltage plateau, an average discharge voltage of the first discharge voltage plateau is higher than an average discharge voltage of the second discharge voltage plateau;
the first battery cells, the second battery cells and the third battery cells each has a cathode active substance which is a mixture of a first cathode active substance having the first discharge voltage plateau and a cathode functional additive having the second discharge voltage plateau;
the cathode functional additive is a titanium oxide, a niobium oxide or a titanium-niobium oxide; and
in each of the first battery cells, the second battery cells and the third battery cells, when a sum of a discharge capacity corresponding to the first discharge voltage plateau and a discharge capacity corresponding to the second discharge voltage plateau is 100%, a proportion of the discharge capacity corresponding to the second discharge voltage plateau in the third battery cells>a proportion of the discharge capacity corresponding to the second discharge voltage plateau in the second battery cells>a proportion of the discharge capacity corresponding to the second discharge voltage plateau in the first battery cells.

2. The battery pack according to claim 1 , wherein,
the interior space of the battery pack container consists of the first region, the second region and the third region.

3. The battery pack according to claim 1 , wherein,
the cathode functional additive is a titanium niobium oxide represented by Ti 2 Nb 2x O 4+5x , wherein x is an integer of 1 or higher.

4. The battery pack according to claim 1 , wherein,
the second discharge voltage plateau has a discharge voltage in a range of 1.0 V-2.0 V, optionally, a discharge capacity of the second discharge voltage plateau in a range of 1.2 V-1.6 V accounts for more than 50% of a total discharge capacity of the second discharge voltage plateau.

5. The battery pack according to claim 1 , wherein,
in the first battery cells, the second battery cells and the third battery cells, a difference between a lowest discharge voltage of the first discharge voltage plateau and a highest discharge voltage of the second discharge voltage plateau is 0.5 V or higher.

6. The battery pack according to claim 1 , wherein,
in the first battery cells, when the sum of the discharge capacity corresponding to the first discharge voltage plateau and the discharge capacity corresponding to the second discharge voltage plateau is 100%, the discharge capacity corresponding to the first discharge voltage plateau accounts for 90%-100%, and the discharge capacity corresponding to the second discharge voltage plateau accounts for 0%-10%.

7. The battery pack according to claim 1 , wherein,
in the second battery cells, when the sum of the discharge capacity corresponding to the first discharge voltage plateau and the discharge capacity corresponding to the second discharge voltage plateau is 100%, the discharge capacity corresponding to the first discharge voltage plateau accounts for 73%-95%, and the discharge capacity corresponding to the second discharge voltage plateau accounts for 5%-27%.

8. The battery pack according to claim 1 , wherein,
in the third battery cells, when the sum of the discharge capacity corresponding to the first discharge voltage plateau and the discharge capacity corresponding to the second discharge voltage plateau is 100%, the discharge capacity corresponding to the first discharge voltage plateau accounts for 54%-87%, and the discharge capacity corresponding to the second discharge voltage plateau accounts for 13%-46%.

9. The battery pack according to claim 1 , wherein,
the cathode active substance of the first battery cells has a specific capacity of 148 mAh/g-285 mAh/g, the cathode active substance of the second battery cells has a specific capacity of 155 mAh/g-295 mAh/g, and the cathode active substance of the third battery cells has a specific capacity of 169 mAh/g-311 mAh/g.

10. The battery pack according to claim 1 , wherein,
the cathode functional additive has a theoretical specific capacity of 350 mAh/g-410 mAh/g.

11. The battery pack according to claim 1 , wherein,
the first cathode active substance is one selected from lithium manganate, lithium nickelate, lithium cobaltate, lithium nickel cobalt manganate, lithium nickel cobalt aluminate, and lithium iron phosphate.

12. The battery pack according to claim 1 , wherein,
when the first battery cells, the second battery cells, and the third battery cells utilize a same type of the first cathode active substance and a same type of the cathode functional additive, respective mass percentages of the first cathode active substance in the cathode active substance decrease in an order of the first battery cells, the second battery cells, and the third battery cells, and respective mass percentages of the cathode functional additive in the cathode active substance increase in an order of the first battery cells, the second battery cells, and the third battery cells.

13. The battery pack according to claim 1 , wherein,
in the first battery cells, when a total mass of the first cathode active substance and the cathode functional additive is 100%, the first cathode active substance accounts for 96.0%-100% by mass and the cathode functional additive accounts for 0%-4.0% by mass.

14. The battery pack according to claim 1 , wherein,
in the second battery cells, when a total mass of the first cathode active substance and the cathode functional additive is 100%, the first cathode active substance accounts for 88.5%-96.0% by mass and the cathode functional additive accounts for 4.0%-11.5% by mass.

15. The battery pack according to claim 1 , wherein,
in the third battery cells, when a total mass of the first cathode active substance and the cathode functional additive is 100%, the first cathode active substance accounts for 76.5%-88.5% by mass and the cathode functional additive accounts for 11.5%-23.5% by mass.

16. The battery pack according to claim 1 , wherein,
the cathode functional additive is a carbon-coated lithium-containing titanium niobium oxide.

17. The battery pack according to claim 1 , wherein,
an anode of each of the first battery cells, the second battery cells and the third battery cells has been subjected to a lithium replenishment treatment.

18. The battery pack according to claim 1 , wherein,
at a temperature of 0° C. or lower, the first battery cells have a discharge cut-off voltage of 1.4 V-1.6 V, the second battery cells have a discharge cut-off voltage of 1.2 V-1.4 V, and the third battery cells have a discharge cut-off voltage of 1.0 V-1.2 V.

19. The battery pack according to claim 1 , wherein,
the number of the first battery cells:the number of the second battery cells:the number of the third battery cells=(3-8):(

Assignees

• Contemporary Amperex Technology Co Ltd

Inventors

• Zhu Chang
• Ouyang Shaocong
• Xu Baoyun
• Xie Tingzhen

Classifications

• H01M50/249

  specially adapted for aircraft or vehicles, e.g. cars or trains (constructional details of batteries specially adapted for electric vehicles B60L50/64) · CPC title

• H01M4/62 Primary

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• 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

• H01M50/204

  Racks, modules or packs for multiple batteries or multiple cells · CPC title