Electrode assembly and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-2021408572-A1
Application number	US-202117470180-A
Country	US
Kind code	A1
Filing date	Sep 9, 2021
Priority date	May 3, 2019
Publication date	Dec 30, 2021
Grant date	—

Abstract

A method for manufacturing an electrode assembly including an N/P ratio examination step (S1) of determining whether an N/P ratio is to be maintained within a predetermined range, the N/P ratio representing a ratio of a loading amount of a positive electrode active material to a loading amount of a negative electrode active material per unit area, an adjustment request area selecting step of selecting an adjustment request area that is expected to have an N/P ratio beyond the predetermined range, and an active material adjusting step in which at least one of a loading amount of the negative electrode active material or a loading amount of the positive electrode active material on a corresponding area of each of a negative electrode and a positive electrode which are to be positioned in the adjustment request area is increased or decreased with respect to a loading amount loaded on other areas.

First claim

1 . A method for manufacturing an electrode assembly in which a negative electrode having a negative electrode active material loaded on a surface of a negative electrode collector, a separator, and a positive electrode having a positive electrode active material loaded on a surface of a positive electrode collector are stacked on each other, the method comprising:
an N/P ratio examination step of determining whether an N/P ratio, which is a ratio of a loading amount of the positive electrode active material to a loading amount of the negative electrode active material per unit area, is to be maintained within a predetermined range in a region in which the negative electrode and the positive electrode face each other when stacked; an adjustment request area selecting step of selecting an adjustment request area that is expected to have an N/P ratio beyond the predetermined range; and an active material adjusting step in which at least one of a loading amount of the negative electrode active material or a loading amount of the positive electrode active material on a corresponding area of each of the negative electrode and the positive electrode which are to be positioned in the adjustment request area is increased or decreased with respect to a loading amount loaded on other areas of the negative electrode and the positive electrode.

2 . The method of claim 1 , wherein, in the active material adjusting step,
when each of the loading amount of the negative electrode active material and the loading amount of the positive electrode active material increases or decreases, the loading amount of one of the negative electrode active material and the positive electrode active material decreases, and the loading amount of the other of the negative electrode active material and the positive electrode active material increases.

3 . The method of claim 1 , wherein, in the active material adjusting step,
when only one of the loading amount of the negative electrode active material or the loading amount of the positive electrode active material increases or decreases, the loading amount of the other of the negative electrode active material or the positive electrode active material is maintained to be equal to the loading amount in the other areas.

4 . The method of claim 1 , wherein, in the adjustment request area selecting step,
at least two adjustment request areas are selected, and an adjusted loading amount to be applied to each of the adjustment request areas is individually determined.

5 . The method of claim 1 , wherein, when the negative electrode, the separator, and the positive electrode are folded in a stacked state and manufactured into the electrode assembly,
a curved section to be curved when the negative electrode and the positive electrode are folded is selected as the adjustment request area in the adjustment request area selecting step.

6 . The method of claim 1 , wherein, when the loading amount of one of the negative electrode active material or the positive electrode active material changes during one of a process of loading the negative electrode active material on the surface of the negative electrode collector or a process of loading the positive electrode active material on the surface of the positive electrode collector,
in the N/P ratio examination step, it is determined that the N/P ratio is to be beyond the predetermined range from a point where the loading amount changes, in the adjustment request area selecting step, when the negative electrode and the positive electrode are stacked, a corresponding area facing a loading amount changing area on which the loading amount of the one of the negative electrode active material and the positive electrode active material changes is selected as the adjustment request area, wherein the corresponding area is an area on which the other of the negative electrode active material and the positive electrode active material is to be loaded, and in the active material adjusting step, the loading amount of the other of the negative electrode active material and the positive electrode active material increases or decreases in the adjustment request area to correspond to the changing loading amount of the one of the negative electrode active material and the positive electrode active material so that the N/P ratio is maintained within a certain range.

7 . The method of claim 1 , wherein, when a difference in thickness occurs because the loading amount of the negative electrode active material or the positive electrode active material which is loaded on the adjustment request area in the active material adjusting step is less than the loading amount on the other areas,
the method further comprises a step (S 4 ) of attaching a tape to the adjustment request area to offset the difference in thickness.

8 . An electrode assembly in which a negative electrode having a negative electrode active material loaded on a surface of a negative electrode collector, a separator, and a positive electrode having a positive electrode active material loaded on a surface of a positive electrode collector are stacked on each other, the electrode assembly comprising:
a flat section in which the negative electrode and the positive electrode are parallel to each other in a flat surface shape; and a curved section which has a curved shape due to folding of the negative electrode and the positive electrode and is connected to an end of the flat section, wherein a loading amount of at least one of the negative electrode active material or the positive electrode active material which is loaded on the curved section is greater or less than a loading amount of each of the negative electrode active material and the positive electrode active material which are loaded on the flat section.

9 . The electrode assembly of claim 8 , wherein an N/P ratio, which is a ratio of the loading amount of the positive electrode active material to the loading amount of the negative electrode active material per unit area, is uniformly maintained within a certain range between the curved section and the flat section.

10 . An electrode assembly in which a negative electrode having a negative electrode active material loaded on a surface of a negative electrode collector, a separator, and a positive electrode having a positive electrode active material loaded on a surface of a positive electrode collector are stacked on each other,
wherein one of the negative electrode or the positive electrode has an active material change area in which a loading amount of the negative electrode active material or the positive electrode active material is beyond a predetermined range, the other of the negative electrode and the positive electrode has an adjustment request area in a region facing the active material change area, and the loading amount of the negative electrode active material or the positive electrode active material in the adjustment request area increases or decreases to correspond to the active material change area so that an N/P ratio, which is a ratio of the loading amount of the positive electrode active material to the loading amount of the negative electrode active material per unit area between the negative electrode and the positive electrode, is maintained within a certain range.

11 . The electrode assembly of claim 10 , wherein a tape is attached to the active material change area to form a flat surface from a surface on which the negative electrode active material or the positive electrode active material is loaded.

Assignees

• Lg Energy Solution Ltd

Inventors

• Yoon Dong Sik

Classifications

• H01M10/4235 Primary

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M4/139

  Processes of manufacture · CPC title

• H01M4/0404 Primary

  by coating on electrode collectors · CPC title