Electrode assembly and rechargeable battery including same

Patent metadata

Field	Value
Publication number	US-11245106-B2
Application number	US-201916376959-A
Country	US
Kind code	B2
Filing date	Apr 5, 2019
Priority date	Apr 12, 2018
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

An electrode assembly and a rechargeable battery including the same are disclosed. The electrode assembly includes a plurality of unit cells overlapping in a thickness direction of the plurality of unit cells and a functional unit cell disposed with the plurality of unit cells. The functional unit cell includes a positive electrode. The positive electrode includes a positive current collector, a positive active material layer on at least one surface of the positive current collector and including a positive active material having a first reference potential, and a functional layer on the positive active material layer and including an active material having a lower reference potential than the first reference potential.

First claim

What is claimed is:

1. An electrode assembly, comprising:
a plurality of unit cells overlapping in a thickness direction of the plurality of unit cells, wherein each cell unit comprises a negative electrode, a positive electrode and a separator between the negative and positive electrodes;
a first functional unit cell at an outermost first surface of the plurality of unit cells; and
a second functional unit cell at an outermost second surface of the plurality of unit cells that is opposite to the first surface,
wherein:
each of the first functional unit cell and the second functional unit cell comprises:
an outer unit cell comprising the negative electrode, an outer positive electrode, and the separator between the negative electrode and the outer positive electrode; and

the outer positive electrode comprises:
a positive current collector,
a positive active material layer on at least one surface of the positive current collector and comprising a positive active material having a first reference potential, and
a first functional layer on the positive active material layer and comprising a first active material having a second reference potential lower than the first reference potential; and

wherein the plurality of cell units do not comprise the first active material.

2. The electrode assembly of claim 1 , wherein the first reference potential is in a range of about 3.3 V to about 4.3 V.

3. The electrode assembly of claim 1 , wherein the second reference potential is in a range of about 1.5 V to about 3.8 V.

4. The electrode assembly of claim 1 , wherein a difference between the first reference potential and the second reference potential is in a range of about 0.01 V to about 2.0 V.

5. The electrode assembly of claim 1 , further comprising a third functional unit cell at the center in the thickness direction of the plurality of unit cells,
wherein:
the third functional unit cell comprises:
a central unit cell comprising a negative electrode, a positive electrode, and a separator between the negative electrode and the positive electrode; and

the positive electrode comprises:
a positive current collector,
a positive active material layer on at least one surface of the positive current collector and comprising a positive active material having the first reference potential, and
a second functional layer on the positive active material layer and comprising a second active material having a third reference potential lower than the first reference potential.

6. The electrode assembly of claim 5 , wherein the third reference potential is in a range of about 1.5 V to about 3.8 V.

7. The electrode assembly of claim 5 , wherein a difference between the first reference potential and the third reference potential is in a range of about 0.01 V to about 2.0 V.

8. An electrode assembly, comprising:
a plurality of unit cells overlapping in a thickness direction of the plurality of unit cells, wherein each cell unit comprises a negative electrode, a positive electrode and a separator between the negative and positive electrodes, and
a third functional unit cell at the center in the thickness direction of the plurality of unit cells,
wherein:
the third functional unit cell comprises:
a central unit cell comprising the negative electrode, a center positive electrode, and the separator between the negative electrode and the positive electrode; and

the center positive electrode comprises:
a positive current collector,
a positive active material layer on at least one surface of the positive current collector and comprising a positive active material having a first reference potential, and
a second functional layer on the positive active material layer and comprising a second active material having a third reference potential lower than the first reference potential; and

wherein the plurality of cell units do not comprise the second active material.

9. The electrode assembly of claim 8 , wherein the first reference potential is in a range of about 3.3 V to about 4.3 V.

10. The electrode assembly of claim 8 , wherein the third reference potential is in a range of about 1.5 V to about 3.8 V.

11. The electrode assembly of claim 8 , wherein a difference between the first reference potential and the third reference potential is in a range of about 0.01 V to about 2.0 V.

12. A rechargeable battery comprising the electrode assembly of claim 1 .

13. The rechargeable battery of claim 12 , wherein the rechargeable battery is a stack-type rechargeable battery, a winding-type rechargeable battery, or a jelly-roll-type rechargeable battery.

14. A rechargeable battery comprising the electrode assembly of claim 8 .

15. The rechargeable battery of claim 14 , wherein the rechargeable battery is a stack-type rechargeable battery, a winding-type rechargeable battery, or a jelly-roll-type rechargeable battery.

16. A method of manufacturing an electrode assembly, the method comprising:
overlapping a plurality of unit cells in a thickness direction of the plurality of unit cells, wherein each cell unit comprises a negative electrode, a positive electrode and a separator between the negative and positive electrodes; and
forming a functional unit cell at an outermost surface or at the center in the thickness direction of the plurality of unit cells, the functional unit cell being formed to comprise a positive electrode, the positive electrode comprising a positive current collector, a positive active material layer on at least one surface of the positive current collector and comprising a positive active material having a first reference potential, and a functional layer on the positive active material layer and comprising an active material having a reference potential lower than the first reference potential; and
wherein the plurality of cell units do not comprise the active material.

17. The method of claim 16 , wherein the forming of the functional unit cell comprises:
forming a first functional unit cell at an outermost first surface of the plurality of unit cells; and
forming a second functional unit cell at an outermost second surface of the plurality of unit cells that is opposite to the first surface,
wherein:
each of the first functional unit cell and the second functional unit cell comprises:
an outer unit cell comprising a negative electrode, a positive electrode, and a separator between the negative electrode and the positive electrode; and

the positive electrode comprises:
a positive current collector,
a positive active material layer on at least one surface of the positive current collector and comprising the positive active material having the first reference potential, and
a first functional layer on the positive active material layer and comprising a first active material having a second reference potential lower than the first reference potential.

18. The method of claim 17 , wherein the forming of the functional unit cell comprises:
forming a third functional unit cell at the center in the thickness direction of the plurality of unit cells,
wherein:
the third functional unit cell comprises:
a central unit cell comprising a negative electrode, a positive electrode, and a separator between the negative electrode and the positive electrode; and

the positive electrode comprises:
a positive current collector,
a positive active material layer on at least one surface of the positive current collector and comprising a positive active material having the first reference potential, and
a second functional layer on th

Assignees

• Samsung Sdi Co Ltd

Inventors

• Ha Jaehwan
• Kim Kijun
• Nam Junghyun
• Seok Hoon
• Yoo Heeeun
• Yoon Yeonhee
• Lee Kyuseo
• Jeon Bokkyu

Classifications

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M10/0525

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

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M10/0585

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title