WO-2026094981-A1 - SECONDARY BATTERY AND SEPARATOR

WO2026094981A1WO 2026094981 A1WO2026094981 A1WO 2026094981A1WO-2026094981-A1

Abstract

This secondary battery comprises an electrode group and a nonaqueous electrolyte. The electrode group includes a positive electrode, a negative electrode facing the positive electrode, and a separator disposed between the positive electrode and the negative electrode. The separator comprises a base material and spacers. The spacers includes linear protrusions formed in a prescribed pattern. The prescribed pattern has disposition regions where the linear protrusions are disposed, and defect regions where the linear protrusions are not disposed in lengthwise portions in which the linear protrusions extend. Each linear protrusion region has end portions in the vicinity of the defect regions and a main portion other than the end portions. The thickness of the end portions of each linear protrusion is less than that of the main portion.

Inventors

MIYAMAE RYOHEI
KANO AKIRA
OKIMOTO RIKIYA

Assignees

パナソニックＩＰマネジメント株式会社

Dates

Publication Date: 20260507
Application Date: 20251030
Priority Date: 20241031

Claims (13)

It comprises an electrode group and a non-aqueous electrolyte, The electrode group includes a positive electrode, a negative electrode facing the positive electrode, and a separator disposed between the positive electrode and the negative electrode. The separator comprises a base material and a spacer, The spacer includes linear protrusions formed along a predetermined pattern, The predetermined pattern includes an arrangement region where the linear protrusions are arranged, and a defect region in which the linear protrusions are not arranged in a part of the length direction in which the linear protrusions extend. The line-shaped protrusion has an end portion near the defect region and a main portion other than the end portion. A secondary battery in which the thickness of the linear protrusion is smaller at the end than that of the main part.
The secondary battery according to claim 1, wherein the thickness of the linear protrusion at the end portion decreases continuously as it moves away from the main portion.
The defect regions are arranged on both sides in the longitudinal direction of the arrangement region. The linear projection has the ends on both sides in the longitudinal direction of the main portion, The secondary battery according to claim 1, wherein the ratio of the total length LE of the ends to the length L0 of the line-shaped protrusions, LE/L0, is 0.2 or more.
The secondary battery according to claim 3, wherein the LE/L0 is 0.5 or greater.
The spacer includes a plurality of linear protrusions, The secondary battery according to any one of claims 1 to 3, wherein at least half of the total number of the plurality of line-shaped protrusions have the ends.
The secondary battery according to claim 5, wherein 4/5 or more of the total number of the plurality of line-shaped protrusions have the ends.
The secondary battery according to any one of claims 1 to 3, wherein the negative electrode is an electrode in which lithium metal is deposited during charging and the lithium metal dissolves in the non-aqueous electrolyte during discharge.
A separator for secondary batteries, The separator comprises a base material and a spacer, The spacer includes linear protrusions formed along a predetermined pattern, The predetermined pattern includes an arrangement region where the linear protrusions are arranged, and a defect region in which the linear protrusions are not arranged in a part of the length direction in which the linear protrusions extend. The line-shaped protrusion has an end portion near the defect region and a main portion other than the end portion. A separator in which the thickness of the linear protrusion is smaller than that of the main part at the end portion.
The separator according to claim 8, wherein at the end portion, the thickness of the line-shaped protrusions continuously decreases as they move away from the main portion.
The defect regions are arranged on both sides in the longitudinal direction of the arrangement region. The linear projection has the ends on both sides in the longitudinal direction of the main portion, The separator according to claim 8, wherein the ratio of the total length LE of the ends to the length L0 of the line-shaped protrusions, LE/L0, is 0.2 or more.
The separator according to claim 10, wherein the LE/L0 is 0.5 or greater.
The spacer includes a plurality of linear protrusions, The separator according to any one of claims 8 to 10, wherein at least half of the total number of the plurality of line-shaped protrusions have the ends.
The separator according to claim 12, wherein 4/5 or more of the total number of the plurality of line-shaped protrusions have the ends.

Description

Secondary batteries and separators Cross-reference of related applications This disclosure claims priority with respect to Japanese Patent Application No. 2024-192160, filed with the Japan Patent Office on October 31, 2024, and the entirety of the said patent application is incorporated herein by reference. This disclosure relates to a secondary battery and a separator used in a secondary battery. A secondary battery comprises an electrode group and a non-aqueous electrolyte. The electrode group includes a positive electrode, a negative electrode, and a separator positioned between the positive and negative electrodes. Examples of secondary batteries include lithium-ion batteries and lithium secondary batteries (lithium metal secondary batteries). In the negative electrode of a lithium secondary battery, lithium metal is deposited during charging, and the lithium metal dissolves into the non-aqueous electrolyte during discharge. To suppress volume changes in the electrode group during charging and discharging, it is conceivable to place a spacer between the separator substrate and the positive or negative electrode. In lithium secondary batteries, the spacer creates a space to accommodate the lithium metal deposited on the negative electrode during charging. Patent Document 1 proposes a lithium secondary battery comprising a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte having lithium ion conductivity, wherein lithium metal is deposited on the negative electrode during charging, and the lithium metal dissolves from the negative electrode during discharge, and a spacer is provided between at least one of the positive electrode and the negative electrode and the separator, the first length of the separator in a first direction D1 is smaller than the second length in a second direction D2 intersecting the first direction D1, and at least one of the angle between the separator and the spacer on the spacer side, and the angle between the electrode in contact with the spacer and the spacer on the spacer side, in the cross-section of the spacer cut along the thickness direction of the separator and the first direction D1, is greater than 90°. This is a schematic top view showing an example of a separator.This is a top view of a portion of the spacer shown in Figure 1.This is a schematic front view showing an example of a linear protrusion.This is a schematic front view showing another example of a linear protrusion.This is a schematic front view illustrating yet another example of a linear protrusion.This is a schematic longitudinal cross-sectional view showing an example of a secondary battery.This is a schematic cross-sectional view showing the main part of the electrode group. The following describes embodiments of this disclosure with examples, but this disclosure is not limited to the examples described below. While specific numerical values and materials may be given as examples in the following description, other numerical values and materials may be applied as long as the effects of this disclosure are achieved. In this specification, the phrase "numerical value A to numerical value B" includes numerical values A and B, and can be interpreted as "greater than or equal to numerical value A and less than or equal to numerical value B." In the following description, when lower and upper limits are given as examples for numerical values of specific physical properties or conditions, any combination of the given lower limits and given upper limits may be used, as long as the lower limit does not exceed the upper limit. When multiple materials are given as examples, one may be selected and used alone, or two or more may be used in combination. This disclosure encompasses any combination of two or more claims, arbitrarily selected from the multiple claims set forth in the attached claims. In other words, any combination of two or more claims, arbitrarily selected from the multiple claims set forth in the attached claims, is permitted, provided that no technical inconsistency arises. The secondary battery according to the embodiment of this disclosure comprises an electrode group and a non-aqueous electrolyte. The electrode group includes a positive electrode, a negative electrode facing the positive electrode, and a separator disposed between the positive and negative electrodes. The separator comprises a substrate and a spacer. The spacer includes linear protrusions formed along a predetermined pattern. The predetermined pattern has a placement region where the linear protrusions are arranged, and a defect region in which the linear protrusions are not arranged in a portion of the longitudinal direction extending from the linear protrusions. The linear protrusions have an end portion near the defect region and a main portion other than the aforementioned end portion. At the end portion, the thickness of the