Electrode Manufacturing Method Comprising Cleaning Step Using Laser, Electrode Manufactured By Method, and Secondary Battery Comprising Same

Patent metadata

Field	Value
Publication number	US-2022149355-A1
Application number	US-202117433858-A
Country	US
Kind code	A1
Filing date	Jan 21, 2021
Priority date	Feb 7, 2020
Publication date	May 12, 2022
Grant date	—

Abstract

The present technology relates to an electrode manufacturing method, an electrode manufactured by the method, and a secondary battery comprising same, the electrode manufacturing method comprising a cleaning step performed by laser irradiation, in lines corresponding to each other in a direction perpendicular to an electrode current collector, onto a top-coated electrode mixture layer and a back-coated electrode mixture layer of the electrode current collector, and may prevent a mismatch of the electrode mixture layers and may significantly reduce the degree of sliding occurrence at the boundary region.

First claim

1 . A method for manufacturing an electrode, comprising:
cleaning an end of a coated part contacting a non-coated part by irradiating laser to a top-coated electrode mixture layer and a back-coated electrode mixture layer of an electrode current collector along a boundary line of the coated part, wherein the cleaning is performed so that a line of irradiating laser to the top-coated electrode mixture layer of the electrode current collector and a line of irradiating laser to the back-coated electrode mixture layer of the electrode current collector correspond to each other in a direction perpendicular to that of the electrode current collector.

2 . The method of claim 1 , wherein during the cleaning, a process of irradiating laser to the top-coated electrode mixture layer of the electrode current collector; and a process of irradiating laser to the back-coated electrode mixture layer of the electrode current collector are performed simultaneously.

3 . The method of claim 1 , wherein during the cleaning, one of two processes including: a process of irradiating laser to the top-coated electrode mixture layer of the electrode current collector; and a process of irradiating laser to the back-coated electrode mixture layer of the electrode current collector is first performed, and a remaining one of the two processes is then performed.

4 . The method of claim 1 , further comprising top-coating an electrode mixture layer and back-coating the electrode mixture layer before the cleaning,
wherein a formation area of the top-coated electrode mixture layer and a formation area of the back-coated electrode mixture layer are in a range of 101 to 105% of an area of a predetermined final electrode mixture layer, respectively.

5 . The method of claim 1 , wherein the cleaning is performed so that a formation angle at the end of the coated part becomes 75° or more on a boundary line of the coated part contacting the non-coated part.

6 . An electrode comprising:
an electrode current collector; a top-coated electrode mixture layer; and a back-coated electrode mixture layer, wherein a ratio (RWa/RWb) of a weight ratio (RWa) of the back-coated electrode mixture layer to the top-coated electrode mixture layer per a unit area (1 cm×1 cm) selected from a region (boundary region) including a boundary line of the coated part, to a weight ratio (RWb) of the back-coated electrode mixture layer to the top-coated electrode mixture layer per a unit area selected from a region (central region) which does not include the boundary line of the coated part, is in a range of 0.85 to 1.15 on a basis of the top-coated electrode mixture layer and the back-coated electrode mixture layer facing each other while interposing the electrode mixture layer therebetween.

7 . The electrode of claim 6 , wherein a formation angle at an end of the top-coated electrode mixture layer and a formation angle at an end of the back-coated electrode mixture layer are in a range of 75° to 90°, respectively, on the boundary line of the coated part contacting the non-coated part.

8 . An electrode assembly comprising:
a positive electrode; a negative electrode; and a separator interposed between the positive electrode and the negative electrode, wherein a ratio (RW2/RW1) of a weight ratio (RW2) of a positive electrode mixture layer to a negative electrode mixture layer per a unit area (1 cm×1 cm) selected from a region (boundary region) including a boundary line of a coated part, to a weight ratio (RW1) of the positive electrode mixture layer to the negative electrode mixture layer per a unit area (1 cm×1 cm) selected from a region (central region) which does not include the boundary line of the coated part is in a range of 0.8 to 1 on a basis of a positive electrode and a negative electrode facing each other while interposing the separator therebetween.

9 . The electrode assembly of claim 8 , wherein the negative electrode includes:
a current collector layer; and a negative electrode mixture layer formed on opposite surfaces of the current collector layer and including a negative electrode active material, wherein the negative electrode active material includes a silicon (Si)-based active material.

10 . The electrode assembly of claim 8 , wherein the negative electrode includes:
a current collector layer; and a negative electrode mixture layer formed on surfaces of the current collector layer and including a negative electrode active material, wherein the negative electrode active material includes a carbon-based active material and a silicon-based active material in a 10 to 95:5 to 90 weight ratio.

11 . A secondary battery comprising an electrode assembly according to claim 8 .

Assignees

• Lg Energy Solution Ltd

Inventors

• Choi Hyoung Sik
• Huh Jun Hyeak
• Kim Jeoung Soo
• Kim Ki Woong
• An In Gu
• Sung Ki Eun

Classifications

• Y02P70/50

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

• B23K26/40

  taking account of the properties of the material involved · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M2010/4292

  Aspects relating to capacity ratio of electrodes/electrolyte or anode/cathode · CPC title