KR20230002207U - Secondary battery - Google Patents

Abstract

An embodiment of the present invention relates to a secondary battery, and the technical problem to be solved is to provide a secondary battery that can increase the strength of the physical bond between the electrode tab and the PCM and the stability of the electrical connection.
For this purpose, the present invention includes a cell including an electrode tab, a PCM, and an ACF disposed between the electrode tab and the PCM to join them, wherein the PCM includes a joint where the ACF is disposed, and a relief portion is provided at the joint. A secondary battery being formed is disclosed.

Description

Secondary battery {SECONDARY BATTERY}

Embodiments of the present invention relate to secondary batteries.

Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged. Low-capacity batteries are used in small, portable electronic devices such as mobile phones and camcorders, and large-capacity batteries are used as a power source for driving motors in hybrid vehicles and electric vehicles. It is widely used. These secondary batteries can be classified into cylindrical, prismatic, polymer, etc. depending on their appearance. Among these, the polymer type uses a pouch to cover the electrode assembly, which has the advantage of high energy density and advantageous space utilization, but has the disadvantage of being relatively vulnerable to external shock.

The above-described information disclosed in the technology behind this design is only intended to improve understanding of the background of this design, and may therefore include information that does not constitute prior art.

Embodiments of the present invention provide a secondary battery that can increase the strength of the physical bond between the electrode tab and the PCM.

Additionally, an embodiment of the present invention provides a secondary battery that can increase the stability of the electrical connection between the electrode tab and the PCM.

A secondary battery according to an embodiment of the present invention includes a cell including an electrode tab, a PCM, and an ACF disposed between the electrode tab and the PCM to join them, wherein the PCM includes a joint where the ACF is disposed, An escape portion may be formed at the joint.

Additionally, the escape portion may be formed to penetrate between the upper and lower surfaces of the joint.

Additionally, the escape portion may be formed in the form of a groove from the upper surface of the joint.

The escape portion may be formed along an edge of the joint.

Additionally, the escape portion may be formed inside the joint portion.

Additionally, the escape portion may be formed in plural numbers.

Additionally, the ACF is provided in the form of a film in which conductive balls are distributed within a binder, and when heat and pressure are applied to the ACF and the binder component flows, the escape portion can accommodate the flowing binder.

In the embodiment of the present invention, an electrode tab and a PCM are joined using an ACF, but when heat and pressure are applied to the ACF and the binder component in the ACF flows, a refuge portion is formed in the PCM to accommodate the flowing binder, Not only can the bonding strength be increased by increasing the contact area of the binder, but the influence of ambient temperature and humidity can be reduced by minimizing the external exposure of the ACF.

1 is a schematic diagram of a secondary battery according to an embodiment of the present invention.
Figure 2 is a cross-sectional view of part II of Figure 1.
Figure 3 is a schematic diagram of the PCM of a secondary battery according to an embodiment of the present invention.
Figure 4 is an enlarged view of part IV of Figure 3.
Figure 5 shows the vicinity of the junction of the PCM of a secondary battery according to another embodiment of the present invention.
Figure 6 shows the vicinity of the junction of the PCM of a secondary battery according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified into various other forms, and the scope of the present invention is as follows. It is not limited to examples. Rather, these embodiments are provided to make the present disclosure more faithful and complete and to fully convey the spirit of the present invention to those skilled in the art.

In addition, in the drawings below, the thickness and size of each layer are exaggerated for convenience and clarity of explanation, and the same symbols refer to the same elements in the drawings. As used herein, the term “and/or” can include any one and any combination of one or more of the listed items. In addition, the meaning of "connected" in this specification refers not only to the case where member A and member B are directly connected, but also to the case where member C is interposed between member A and member B to indirectly connect member A and member B. do.

The terms used in this specification are used to describe specific embodiments and are not intended to limit the present invention. As used herein, the singular forms include the plural forms unless the context clearly indicates otherwise. Additionally, when used herein, “comprise, include,” and/or “comprising, including” refer to mentioned shapes, numbers, steps, operations, members, elements, and/or these. It specifies the presence of a group and does not exclude the presence or addition of one or more other shapes, numbers, movements, members, elements and/or groups.

Although the terms first, second, etc. are used herein to describe various members, parts, regions, layers and/or parts, these members, parts, regions, layers and/or parts are limited by these terms. It is obvious that this cannot be done. These terms are used only to distinguish one member, component, region, layer or section from another region, layer or section. Accordingly, a first member, part, region, layer or portion described below may refer to a second member, part, region, layer or portion without departing from the teachings of the present invention.

Space-related terms such as “beneath,” “below,” “lower,” “above,” and “upper” are used to refer to an element or feature shown in a drawing. It can be used to facilitate understanding of other elements or features. These terms related to space are for easy understanding of the present invention according to various process states or usage states of the present invention, and are not intended to limit the present invention. For example, if an element or feature in a drawing is turned over, an element or feature described as “bottom” or “below” becomes “top” or “above.” Therefore, “lower” is a concept encompassing “upper” or “lower.”

Figure 1 is a schematic diagram of a secondary battery 100 according to an embodiment of the present invention, and Figure 2 is a cross-sectional view of part II of Figure 1. In addition, FIG. 3 is a schematic diagram of the PCM 120 of the secondary battery 100 according to an embodiment of the present invention, and FIG. 4 is an enlarged view of portion IV of FIG. 3, showing the secondary battery according to an embodiment of the present invention. It shows the vicinity of the junction 121 of the PCM 120 at (100).

1 to 4, the secondary battery 100 according to an embodiment of the present invention includes a cell 110, a PCM 120, and an ACF 130.

The cell 110 includes an electrode assembly (not shown), a first electrode tab 111-1, a second electrode tab 111-2, and a case 112.

The electrode assembly includes a first electrode plate, a second electrode plate, and a separator.

The first electrode plate may be either a negative electrode plate or a positive electrode plate. When the first electrode plate is a negative electrode plate, the first electrode plate may include a negative electrode current collector plate made of a conductive metal thin plate, for example, copper or nickel foil or mesh, a negative electrode coating portion coated with a negative electrode active material, and a negative electrode uncoated portion not coated with the negative electrode active material. You can. The negative electrode active material may be made of carbon-based material, Si, Sn, tin oxide, tin alloy composite, transition metal oxide, lithium metal nitrite, or metal oxide.

The second electrode plate may be one of a negative electrode plate and a positive electrode plate. As described above, if the first electrode plate is a negative electrode plate, the second electrode plate becomes a positive electrode plate. In this case, the second electrode plate may include a positive electrode coating portion coated with a positive electrode active material on a positive electrode current collector plate made of a conductive metal thin plate, for example, aluminum foil or mesh, and a positive electrode uncoated portion not coated with the positive electrode active material. The positive electrode active material may be made of a complex metal oxide such as a chalcogenide compound, for example, LiCoO ₂ , LiMn ₂ O ₄ , LiNiO ₂ , LiNiMnO ₂ .

The separator is interposed between the first electrode plate and the second electrode plate and serves to prevent short circuit between the first electrode plate and the second electrode plate. The separator may be made of polyethylene, polypropylene, a porous copolymer of polyethylene and polypropylene, etc.

Case 112 accommodates the electrode assembly and electrolyte solution. Case 112 includes a first pouch member mainly surrounding one side of the electrode assembly and a second pouch member mainly surrounding the opposite side of the electrode assembly, and the first pouch member and the second pouch member are to be joined along the edge. You can. The first pouch member and the second pouch member may be manufactured separately, or may be manufactured as one piece and connected in a foldable manner.

The first electrode tab 111-1 is electrically connected to the first electrode plate of the electrode assembly and is drawn out from there through between the first pouch member and the second pouch member. At this time, the first electrode tab 111-1 may be provided with an insulating member at a portion that contacts the case 112 to prevent short circuit with the case 112.

The second electrode tab 111-2 is electrically connected to the second electrode plate of the electrode assembly and is drawn out from there through between the first and second pouch members. At this time, the second electrode tab 111-2 may be provided with an insulating member at a portion that contacts the case 112 to prevent short circuit with the case 112.

Hereinafter, the first electrode tab 111-1 and the second electrode tab 111-2 will be collectively referred to as 'electrode tab 111'.

The printed circuit module (PCM) 120 serves to prevent overcharge, overdischarge, and/or overcurrent of the cell 110. To this end, the PCM 120 may include appropriate elements such as PTC (Positive Temperature Coefficient), and the related configuration itself may be substantially the same as known, or to a degree that can be easily derived from what is known by those skilled in the art. Therefore, detailed description of this will be omitted.

The PCM 120 includes a joint portion 121 on which the ACF 130 is disposed and connected to the electrode tab 111 through the ACF 130. The junction 121 has a specific structure, which will be described later.

ACF (Anistropic Conductive Film) 130 is disposed between the electrode tab 111 and the PCM 120, and serves to physically couple the electrode tab 111 and the PCM 120 and at the same time electrically connect them. To this end, the ACF 130 may be formed, for example, in the form of a film in which a plurality of conductive balls are distributed within an acrylic-based binder. Additionally, the conductive ball may be formed in the form of a ball coated with a metal material such as gold (Au), nickel (Ni), or palladium (Pd) using a polymer material. When heat and pressure are applied to the ACF (130), the conductive balls collide with each other, causing the outer polymer material to peel off and the inner metal material to melt. Accordingly, both sides of the ACF 130 are connected by the molten metal material and become conductive.

Meanwhile, when heat and pressure are applied to the ACF (130), the binder component in the ACF (130) flows slightly, and the PCM (120) has a relief portion (122) to accommodate the binder flowing at the joint portion (121). do. According to this, not only can the joint strength be increased by increasing the area where the binder is in contact with the joint 121 (see FIG. 2), but also by inducing the binder to flow in a certain position or direction, process quality and dispersion can be reduced, By minimizing the binder's exposure to the outside, it can reduce the influence of ambient temperature and humidity.

In Figure 4, the escape portion 122 is illustrated as being formed penetrating between the upper and lower surfaces of the joint portion 121. Additionally, in Figure 4, the escape portion 122 is illustrated as being formed along the edge of the joint portion 121. For example, it can be said that the escape portion 122 penetrates between the upper and lower surfaces of the joint portion 121 and is formed in a semicircular shape along the edge of the joint portion 121. This structure is advantageous for multiple connections because it is possible to form a relief portion at each corner of two joints at a time by machining a number of circular holes in a row in the substrate and then cutting them along the center.

However, the escape portion 122 does not necessarily have to be formed in a semicircular shape, and the escape portion 122 may be formed in a triangle, square, or oval shape, if necessary.

In addition, in FIG. 4, it is illustrated that five escape portions 122 are formed at each corner, but if necessary, the escape portions 122 may be formed only at one corner, one, two, or three. , may be formed of four or six or more.

Figure 5 shows the vicinity of the junction 221 of the PCM of a secondary battery according to another embodiment of the present invention.

When compared to the secondary battery 100 according to an embodiment of the present invention described with reference to FIGS. 1 to 4, the secondary battery according to another embodiment of the present invention has the escape portion 222 at the edge of the joint portion 221. Although it is the same in that it is formed along the joint 221, there is a difference in that it is formed in the form of a groove at a certain depth from the upper surface of the joint 221, rather than penetrating between the upper and lower surfaces of the joint 221.

Other details are substantially the same as those of the secondary battery 100 according to an embodiment of the present invention, and even if there are differences, it is to the extent that a person skilled in the art would naturally be expected to change in response to the above differences. Repetitive explanations are omitted.

Figure 6 shows the vicinity of the junction 321 of the PCM of a secondary battery according to another embodiment of the present invention.

When compared to the secondary battery 100 according to an embodiment of the present invention described with reference to FIGS. 1 to 4, the secondary battery according to another embodiment of the present invention has the escape portion 322 of the joint portion 321. The difference is that it is formed inside the joint 321, rather than along the edge.

This escape portion 322 may be formed in the form of a hole by penetrating between the upper and lower surfaces of the joint 321, or may be formed in the form of a groove at a certain depth from the upper surface of the joint 321. In addition, in the case of the secondary battery according to another embodiment of the present invention, of course, the escape portion 322 can be formed in various shapes, numbers, and arrangements as needed.

Other details are substantially the same as those of the secondary battery 100 according to an embodiment of the present invention, and even if there are differences, it is to the extent that a person skilled in the art would naturally be expected to change in response to the above differences. Repetitive explanations are omitted.

What has been described above is only one embodiment for implementing the secondary battery according to the present invention, and the present invention is not limited to the above-described embodiments, and goes beyond the gist of the present invention as claimed in the following patent claims. Without this, anyone with ordinary knowledge in the field to which the design pertains will say that the technical spirit of the present design exists to the extent that various modifications and implementations are possible.

100: Secondary battery
110: cell
111: electrode tab (111-1: first electrode tab, 111-2: second electrode tab)
112: case
120:PCM
121, 222, 322: junction
122, 222, 322: Escape Department
130:ACF

Claims (7)

A cell containing electrode tabs,
PCM and
Includes an ACF disposed between the electrode tab and the PCM to join them,
A secondary battery wherein the PCM includes a junction where the ACF is disposed, and an escape portion is formed at the junction. According to paragraph 1,
A secondary battery in which the escape portion is formed by penetrating between the upper and lower surfaces of the joint. According to paragraph 1,
A secondary battery wherein the escape portion is formed in the form of a groove from the upper surface of the joint. According to paragraph 1,
A secondary battery wherein the escape portion is formed along an edge of the joint. According to paragraph 1,
A secondary battery wherein the escape portion is formed inside the joint portion. According to paragraph 1,
A secondary battery in which a plurality of escape portions are formed. According to paragraph 1,
The ACF is provided in the form of a film with conductive balls distributed within a binder, and when heat and pressure are applied to the ACF and the binder component flows, the escape portion accommodates the flowing binder.