Method for producing lithium metal negative electrode structure and lithium metal negative electrode structure

Patent metadata

Field	Value
Publication number	US-11228029-B2
Application number	US-201816604930-A
Country	US
Kind code	B2
Filing date	Sep 6, 2018
Priority date	Oct 27, 2017
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

A method for producing a lithium metal negative electrode structure including the steps of: (a) forming a lithium metal layer on a portion of one side or both sides of a current collector, wherein a non-coated portion of the current collector, on which a tab will be formed, is included on one side of the current collector, and wherein a stepped part is present between the non-coated portion of the current collector and the coated portion of the lithium metal layer; (b) coating and curing a photocurable material, or attaching an insulating tape, onto the stepped part between the non-coated portion of the current collector and the coated portion of the lithium metal layer; and (c) punching the result of step (b) into a unit electrode to produce the lithium metal negative electrode structure.

First claim

The invention claimed is:

1. A method for producing a lithium metal negative electrode structure comprising the steps of:
(a) forming a lithium metal layer on a portion of one side or both sides of a current collector,
wherein a non-coated portion of the current collector, on which a tab will be formed, is included on one side of the current collector, and wherein a stepped part is present between the non-coated portion of the current collector and the coated portion of the lithium metal layer;
(b) coating and curing a photocurable material, or attaching an insulating tape, onto the stepped part between the non-coated portion of the current collector and the coated portion of the lithium metal layer; and
(c) punching the result of step (b) into a unit electrode to produce the lithium metal negative electrode structure,
wherein the tab extends from one side of the unit electrode such that a length of the tab along the one side of the unit electrode is less than a length of the one side of the unit electrode, and
wherein a length of the photocurable material or insulating tape along the one side of the unit electrode is greater than the length of the tab and less than the length of the one side of the unit electrode.

2. The method for producing the lithium metal negative electrode structure according to claim 1 , wherein the method further comprises forming the tab by punching the non-coated portion of the current collector simultaneously with step (c).

3. The method for producing the lithium metal negative electrode structure according to claim 1 , wherein the method further comprises (d) forming the tab by punching the non-coated portion of the current collector after step (c).

4. The method for producing the lithium metal negative electrode structure according to claim 1 , wherein the stepped part is a portion having a width of 2 mm to 5 mm extending along a boundary between the non-coated portion of the current collector and the coated portion where the lithium metal layer is formed.

5. The method for producing the lithium metal negative electrode structure according to claim 1 , wherein in step (b) the photocurable material is coated and cured, and the photocurable material is an ultraviolet curable material and is cured by irradiation with ultraviolet rays.

6. The method for producing the lithium metal negative electrode structure according to claim 5 , wherein the ultraviolet curable material is an oligomer or a low molecular weight polymer having a viscosity of 10 cps to 100 cps which is then cured by irradiating ultraviolet rays.

7. The method for producing the lithium metal negative electrode structure according to claim 6 , wherein the oligomer is at least one selected from the group consisting of epoxy-based, urethane-based, acrylate-based, silicone-based, hydroxyl-based and acrylic acid derivatives, and the low molecular weight polymer is at least one selected from the group consisting of an unsaturated polyester-based material and a polyacrylate-based material.

8. The method for producing the lithium metal negative electrode structure according to claim 1 , wherein a coating thickness of the photocurable material or a thickness of the insulating tape is 10 nm to 1 μm.

9. The method for producing the lithium metal negative electrode structure according to claim 1 , wherein the current collector is copper, copper alloy, stainless steel, aluminum, or nickel.

10. The method for producing the lithium metal negative electrode structure according to claim 1 , wherein the lithium metal layer has a thickness of 20 μm to 100 μm.

11. The method for producing the lithium metal negative electrode structure according to claim 1 , wherein step (a) is performed by vapor-depositing or pressing the lithium metal layer on the current collector.

12. A lithium metal negative electrode structure comprising:
a current collector;
a tab extending from the current collector; and
a lithium metal layer formed on one side or both sides of the current collector excluding the tab,
wherein an insulating layer comprising a cured photocurable material is formed, or an insulating tape is attached, onto a stepped part between the tab and the lithium metal layer,
wherein the tab extends from one side of the unit electrode such that a length of the tab along the one side of the unit electrode is less than a length of the one side of the unit electrode, and
wherein a length of the insulating layer or the insulating tape along the one side of the unit electrode is greater than the length of the tab and less than the length of the one side of the unit electrode.

13. The lithium metal negative electrode structure according to claim 12 , wherein the tab is integrally formed with the current collector.

14. The lithium metal negative electrode structure according to claim 12 , wherein the insulating layer or the insulating tape is formed to cover an end of the lithium metal layer and an end of the tab.

15. The lithium metal negative electrode structure according to claim 12 , wherein a width of the insulating layer or the insulating tape is 2 mm to 5 mm extending along a boundary between the lithium metal layer and the tab.

16. The lithium metal negative electrode structure according to claim 12 , wherein a width of the insulating layer or the insulating tape is equal to a width of the tab.

17. The lithium metal negative electrode structure according to claim 12 , wherein a thickness of the insulating layer or the insulating tape is 10 nm to 1 μm.

18. A secondary battery comprising the lithium metal negative electrode structure according to claim 12 .

Assignees

• Lg Chemical Ltd

Inventors

• Lee Sangkyun
• Choi Baeck Boem
• Ku Cha Hun
• Kim Minwook

Classifications

• H01M4/0435

  Rolling or calendering · CPC title

• H01M4/134 Primary

  Electrodes based on metals, Si or alloys · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/1393 Primary

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title