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JP-2026075061-A - Secondary batteries, battery packs, and electronic devices

JP2026075061AJP 2026075061 AJP2026075061 AJP 2026075061AJP-2026075061-A

Abstract

[Problem] The present invention provides a secondary battery, a battery pack, and an electronic device that can avoid damaging the separator at least during the manufacturing process. [Solution] Embodiments of the present invention provide a secondary battery, a battery pack, and an electronic device, the secondary battery including an electrode assembly, the electrode assembly including a negative electrode sheet, a positive electrode sheet, and a separator placed between the negative electrode sheet and the positive electrode sheet, the uncoated negative electrode area of the negative electrode sheet including a negative electrode tab and a negative electrode connection area connected between the negative electrode tab and the negative electrode coated area, the negative electrode tab including a negative electrode tab body and a negative electrode tab transition portion connected between the negative electrode connection area and the negative electrode tab body, the negative electrode tab transition portion including a first negative electrode tab transition endpoint, the first negative electrode tab transition endpoint being the position where the tangent to the negative electrode tab transition portion and the extending direction of the negative electrode connection area intersect, and the distance in the first direction between the first negative electrode tab transition endpoint and the first separator end in the first direction of the separator being 0.5 to 2 mm. [Selection Diagram] Figure 6A

Inventors

  • 張 文晶

Assignees

  • 株式会社ＡＥＳＣジャパン

Dates

Publication Date
20260507
Application Date
20250930
Priority Date
20241021

Claims (10)

  1. The electrode assembly includes a negative electrode sheet, a positive electrode sheet, and a separator placed between the negative electrode sheet and the positive electrode sheet. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode current collector includes a negative electrode coated region covered by the negative electrode active material layer and a negative electrode uncoated region not covered by the negative electrode active material layer, the direction from the negative electrode coated region to the negative electrode uncoated region is defined as the first direction, and the separator includes a first separator end in the first direction. Along the first direction, the uncoated negative electrode region includes a negative electrode tab and a negative electrode connection portion connected between the negative electrode tab and the negative electrode coated region, the negative electrode tab includes a negative electrode tab body and a negative electrode tab transition portion connected between the negative electrode connection portion and the negative electrode tab body, the negative electrode tab transition portion includes a first negative electrode tab transition endpoint connected to the negative electrode connection portion, the first negative electrode tab transition endpoint is the position where the tangent to the negative electrode tab transition portion intersects with the direction in which the negative electrode connection portion extends, A secondary battery characterized in that the distance over which the first negative electrode tab transition endpoint protrudes beyond the first separator end in the first direction is 0.5 to 2 mm.
  2. The secondary battery according to claim 1, characterized in that the negative electrode active material layer includes a first negative pole in the first direction, and the distance over which the first negative electrode tab transition endpoint extends beyond the first negative pole in the first direction is 1.5 to 3 mm.
  3. The secondary battery according to claim 2, characterized in that the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer includes a first positive electrode end in the first direction, and the distance by which the first negative electrode end extends beyond the first positive electrode end in the first direction is 1.0 to 1.5 mm.
  4. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode current collector includes a positive electrode coated region covered by the positive electrode active material layer and a positive electrode uncoated region not covered by the positive electrode active material layer, the direction from the positive electrode coated region to the positive electrode uncoated region is defined as the second direction, and the second direction is the opposite direction to the first direction. Along the second direction, the uncoated positive electrode region includes a positive electrode tab and a positive electrode connection portion connected between the positive electrode tab and the positive electrode coated region, the positive electrode tab includes a positive electrode tab body and a positive electrode tab transition portion connected between the positive electrode connection portion and the positive electrode tab body, the positive electrode tab transition portion includes a first positive electrode tab transition endpoint connected to the positive electrode connection portion, the first positive electrode tab transition endpoint is the position where the tangent to the positive electrode tab transition portion intersects with the direction in which the positive electrode connection portion extends, The secondary battery according to claim 1, wherein the electrode assembly further includes an insulating layer, the insulating layer covers the positive electrode connection portion, and the width of the insulating layer in the second direction is 0.5 to 2.5 mm.
  5. The secondary battery according to claim 4, characterized in that the negative electrode active material layer includes a second negative electrode end in the second direction, the insulating layer includes a first insulating layer end in the first direction, and the distance over which the second negative electrode end extends beyond the first insulating layer end in the second direction is 0.5 to 1 mm.
  6. The secondary battery according to claim 5, characterized in that the insulating layer includes the second insulating layer end in the second direction, and the distance over which the second insulating layer end extends to the second negative pole end in the second direction is 0.5 to 1 mm.
  7. The secondary battery according to claim 1, characterized in that the negative electrode active material layer includes a first negative pole in the first direction, and the distance over which the first separator end extends beyond the first negative pole in the first direction is 0.5 to 1.5 mm.
  8. The case further comprises a case used to house the electrode assembly, the case including a circumferential side wall and an end wall connected to one end of the circumferential side wall, the other end of the circumferential side wall having an opening, the circumferential side wall adjacent to the opening having a pressure contact portion projecting inward, and the electrode assembly being positioned between the end wall and the pressure contact portion. The negative electrode tab faces the opening and is connected to the case via a negative electrode current collector plate, and the welding position between the negative electrode current collector plate and the circumferential wall is located on the side of the pressure-welded portion facing the electrode assembly. The secondary battery according to claim 4, characterized in that the secondary battery is a cylindrical battery.
  9. A battery pack characterized by including a secondary battery as described in any one of claims 1 to 8.
  10. An electronic device characterized by including the battery pack described in claim 9.

Description

This invention relates to a secondary battery, a battery pack, and an electronic device. In the field of new energy power batteries, the applications of secondary batteries are becoming increasingly widespread. For example, secondary batteries (e.g., lithium-ion batteries) can be applied to vehicles, energy storage devices, mobile phones, tablet computers, wearable devices, mobile power supplies, e-cigarettes, digital products, power tools, power units, energy storage devices, and other electronic devices. One type of secondary battery is the cylindrical battery, which includes a shell and an electrode assembly. The electrode assembly includes a positive electrode sheet, a first separator, a negative electrode sheet, and a second separator, which are sequentially stacked and then wound to form the electrode assembly, which is then sealed inside the shell. However, existing secondary batteries still require further improvement in certain aspects. To more clearly describe the embodiments of the present invention or the technical concepts in the prior art, the accompanying drawings that may be used in the description of the embodiments or prior art are briefly introduced below. Clearly, the accompanying drawings in the following description are some embodiments of the present invention, and those skilled in the art can obtain other accompanying drawings based on these without expending any creative effort. This is an explanatory diagram showing an example of the present invention where the electronic device is in a vehicle.This is a perspective view of a secondary battery based on an embodiment of the present invention.This is a cross-sectional view of a secondary battery based on an embodiment of the present invention.This is a cross-sectional view of an electrode assembly based on several embodiments.This is a cross-sectional diagram illustrating region A1 of the negative electrode sheet in Figure 4.This is a cross-sectional diagram illustrating region A2 of the positive electrode sheet in Figure 4.This is a cross-sectional diagram illustrating the relevant dimensions of the negative electrode sheet in electrode assemblies of several embodiments.This is a cross-sectional diagram illustrating the relevant dimensions of the negative electrode sheet in an electrode assembly based on several embodiments.This is an explanatory diagram showing the relationship between the positive electrode sheet and the negative electrode sheet in an electrode assembly based on several embodiments. To better understand the spirit of the embodiments of the present invention, some preferred embodiments of the present invention will be described further below in combination. Embodiments of the present invention are described in detail below. Throughout the entirety of this specification, identical or similar components and components having identical or similar functions are represented by similar reference numerals. The embodiments relating to the drawings described herein are explanatory and illustrative in nature and are used to provide a basic understanding of the present invention. These embodiments should not be construed as limitations of the present invention. The terms "approximately," "basically," "substantially," and "about" used in this text are used to describe and explain small changes. When used in conjunction with events or situations, these terms can refer to examples where the event or situation occurs exactly, as well as examples where the event or situation occurs very approximately. In this specification, unless otherwise specified or limited, terms of relativity, such as “center,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “internal,” “external,” “lower,” “higher,” “horizontal,” “vertical,” “higher,” “lower,” “upward,” “downward,” “top,” “bottom,” and their derived terms (e.g., “horizontally,” “downward,” “upward,” etc.), should be interpreted as referring to the direction described in the discussion or in the drawings. These terms of relativity are used solely for descriptive convenience and do not require the invention to be constructed or operated in a particular direction. For convenience of description, terms such as "First," "Second," "Third," etc., may be used in the text to distinguish different components of a single figure or a series of figures. These terms are not intended to describe corresponding components. Furthermore, where not contradictory, the embodiments and features described herein can be combined. The present invention will be described in detail below in combination with the embodiments, with reference to the drawings. The present invention provides an electronic device 1000, and in the following embodiments, for the sake of explanation, the case in which the electronic device 1000 is a vehicle will be described as an example. Referring to Figure 1, a battery pack 1002 is installed inside the vehicle, and the battery pack 1002 can be installed at the bottom, front, or