KR20230045514A - A pouch for battery and battery comprising the same - Google Patents

Abstract

A pouch for a battery and a battery including the pouch are disclosed. A battery according to various embodiments of the present invention comprises: a battery cell including an anode, a cathode, and a separator separating the anode and the cathode, and having a shape including at least one flat surface and at least one curved surface; and a pouch surrounding the outside of the battery cell. The pouch comprises: a first polymer layer that is molded to have at least one internal space where each of battery cells is located and includes a polymer film that seals each of the battery cells and surrounds the outside of each of the battery cells; a second polymer layer that entirely surrounds the outside of the first polymer layer and has higher strength and rigidity than the first polymer layer; a metal layer including a thin plate of metal laminated and attached to the inner surface of the second polymer layer; and an adhesive layer located between the inner surface of the metal layer and the first polymer layer, and bonding a portion of the inner surface of the metal layer and the inner surface of the first polymer layer to each other. The risk of damage during sealing and bending is reduced.

Description

A pouch for a battery and a battery including the same {A POUCH FOR BATTERY AND BATTERY COMPRISING THE SAME}

Various embodiments disclosed herein relate to a battery, and more particularly, to a pouch for a battery and a battery including the pouch.

Recently, secondary batteries, which are batteries capable of storing and outputting electrical energy, have been widely used due to the development of portable electronic devices. A lithium ion battery is a secondary battery that is lightweight, has high energy density, and has good charge/discharge characteristics, and is widely used in fields such as electric vehicles and energy storage systems (ESSs) as well as portable electronic devices.

A battery of an electronic device may include a battery cell including a positive electrode, a negative electrode, and an electrolyte, and a pouch that covers the outside of each battery cell and protects the battery cell. The pouch may be manufactured by cutting and sealing fabric made of a composite material composed of a plurality of layers having different physical and chemical properties. An electronic device may include a battery pack or a battery module including a plurality of battery cells in order to optimize the arrangement of internal components.

When the battery module includes a plurality of battery cells, the space required due to the thickness of the pouch surrounding the battery cells and the thickness of the sealing portion of the pouch is excessive, which reduces the size of the battery module including a plurality of battery cells. There is a certain limit to the battery pouch, and damage such as cracks, tears, or whitening of polymers may occur in the pouch due to differences in physical properties of different layers included in the pouch during sealing and bending of the battery pouch.

Various embodiments disclosed in this document may provide a battery and a pouch for a battery in which the risk of damage during sealing and bending is reduced and the distance between a plurality of battery cells is reduced.

A battery according to various embodiments of the present invention includes a positive electrode, a negative electrode, and a separator separating the positive electrode and the negative electrode, and has a shape including at least one flat surface and at least one curved surface, the battery An inner pouch including an inner space in which a cell is located and including a polymer material on a thin film covering and sealing the outside of the battery cell, a second polymer layer covering the outside of the inner pouch, and an inner surface of the second polymer layer An outer pouch including a metal layer attached to the outer pouch, and an adhesive layer positioned between the inner pouch and the outer pouch and bonding an outer surface of the inner pouch and a part of the inner surface of the outer pouch to each other. In some embodiments, the battery cell may be a jelly-roll having a stadium-shaped cross section by winding the positive electrode, the negative electrode, and the separator in the form of plates stacked on each other. In some embodiments, the adhesive layer may include a heat activated adhesive.

In some embodiments, the polymer material of the inner pouch may include a thermoplastic polymer material. In another embodiment, the thermoplastic polymer material may include cast polypropylene (CPP).

In some embodiments, the inner pouch includes a flange portion in which polymer materials on the thin film are bonded to each other so that the inner space is sealed against the outside, and the flange portion is bent to face the outer surface of the inner pouch, It may be located inside the outer pouch. In some embodiments, the inner pouch includes at least one flat portion and at least one curved portion, and the adhesive layer mutually bonds the flat portion of the inner pouch and a region of the inner surface of the outer pouch facing the flat portion to each other. can make it

In some embodiments, the inner pouch includes a plurality of battery cells disposed in parallel in a horizontal direction with respect to a plane of the battery cells, and the inner pouch has a plurality of inner pouches in which a plurality of the battery cells are respectively located and separated from each other. space may be included. In some embodiments, the inner pouch may include a segment portion that is a region in which the polymer material is mutually joined to divide a plurality of the inner spaces. In some embodiments, the inner pouch may include a segment portion that is a region in which the polymer material is mutually joined to divide a plurality of the inner spaces.

In some embodiments, a plurality of battery cells stacked in a vertical direction with respect to a plane of the battery cells, and a plurality of inner pouches wrapped around and stacked, respectively, the plurality of stacked battery cells, wherein the outer pouch may entirely cover the plurality of stacked internal pouches from the outside. In some embodiments, the plurality of inner pouches may be bonded to each other in a region where the plurality of inner pouches are stacked and overlap each other. In some embodiments, the plurality of battery cells may include a first battery cell and a second battery cell having a relatively smaller size than the first battery cell.

A pouch for a battery according to another embodiment of the present invention includes a battery cell having a shape including a positive electrode, a negative electrode, and a separator for separating the positive electrode and the negative electrode, and including at least one flat surface and at least one curved surface. A pouch for a battery, including an inner space where the battery cell is located, an inner pouch including a thin-film polymer material surrounding and sealing the battery cell, a second polymer layer and the second polymer layer covering the outside of the inner pouch. 2 An outer pouch comprising a metal layer attached to an inner surface of the polymer layer, and located between the inner pouch and the outer pouch, wherein at least a portion of the outer surface of the inner pouch and the inner surface of the outer pouch are mutually adhered. An adhesive layer may be included. In some embodiments, the polymer material of the inner pouch may include a thermoplastic polymer material. In some embodiments, the thermoplastic polymer material may include cast polypropylene (CPP).

In some embodiments, the inner pouch includes a flange portion to which the thin-film polymer material is bonded to each other so as to seal the inner space, and the flange portion is bent to face an outer surface of the inner pouch so as to be inside the outer pouch. can be located

In some embodiments, the inner pouch includes at least one flat portion and at least one curved portion, and the adhesive layer mutually bonds the flat portion of the inner pouch and a region of the inner surface of the outer pouch facing the flat portion to each other. can make it

In some embodiments, the inner pouch may include a plurality of inner spaces separated from each other, and a segment portion that is a region in which the polymer material is mutually joined to divide the plurality of inner spaces. In some embodiments, the inner pouch may include a plurality of stacked inner pouches, and the plurality of inner pouches may be bonded to each other in an area where the plurality of inner pouches are stacked and overlapped.

According to various embodiments disclosed in this document, a pouch of a battery includes an inner pouch and an outer pouch, and the inner pouch is joined and bent to form a flange portion and seal the battery cell, thereby reducing the risk of damage during sealing and bending processing. A battery having a reduced distance between a plurality of battery cells and a pouch for a battery having the above characteristics may be provided.

In connection with the description of the drawings, the same or similar reference numerals may be used for the same or similar elements.
1 is a cross-sectional perspective view schematically showing the structure of a battery according to various embodiments.
Figure 2a is a cross-sectional view showing a battery according to embodiments of the present invention.
2B is an enlarged cross-sectional view of a battery according to various embodiments of the present invention.
Figure 2c is a schematic diagram showing the laminated structure of the battery pouch according to an embodiment of the present invention.
3A is an enlarged cross-sectional view of a battery in accordance with some embodiments of the invention.
3B is an enlarged cross-sectional view comparing a battery according to an embodiment of the present invention and a battery according to a comparative example.
4A is a perspective view of a battery according to another embodiment of the present invention.
4B is a cross-sectional view of a battery according to another embodiment of the present invention.
4C is a cross-sectional view of a battery according to another embodiment of the present invention and a battery according to a comparative example.
4D is an internal perspective view of a battery according to another embodiment of the present invention.
5A is a cross-sectional view of a battery in accordance with some embodiments of the invention.
5B is an enlarged cross-sectional view illustrating a battery according to an embodiment of the present invention and a battery according to a comparative example.
5C is an internal perspective view illustrating a battery according to still another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In these drawings, for example, the size and shape of members may be exaggerated for convenience and clarity of explanation, and deformations of the illustrated shapes may be expected in actual implementation. Accordingly, embodiments of the present invention should not be construed as being limited to the specific shape of the region shown herein.

Reference numerals of members in the drawings refer to the same members throughout the drawings. Also, as used herein, the term "and/or" includes any one and all combinations of one or more of the listed items.

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 in many different forms, and the scope of the present invention is as follows It is not limited to the examples. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the spirit of the invention to those skilled in the art.

Terms used in this specification are used to describe the embodiments, and are not intended to limit the scope of the present invention. In addition, even if it is described in the singular in this specification, it may include a plurality of forms unless the context clearly indicates the singular. Also, as used herein, the terms "comprise" and/or "comprising" specify the presence of the mentioned shapes, numbers, steps, operations, members, elements and/or groups thereof. and does not exclude the presence or addition of other shapes, numbers, operations, elements, elements and/or groups.

As used herein, "below", "above", "upper", "lower", "horizontal" or "vertical" Relative terms such as may be used to describe the relationship of one constituent member, layer or region to another constituent member, layer or region, as shown in the drawings. It should be understood that these terms encompass directions indicated in the drawings as well as other directions.

1 is a cross-sectional perspective view schematically showing the structure of a battery according to various embodiments.

Referring to FIG. 1 , a battery 100 may include a cathode 160 (positive electrode), a cathode 150 (negative electrode), and a separator 170 (separator). The positive electrode 160 may be an electrode that functions as a cathode when the battery is discharged and forms a lithium compound by absorbing lithium ions from the electrolyte. Lithium compounds include lithium cobalt oxide (LixCoO ₂ ), lithium nickel oxide (LixNiO ₂ ), lithium nickel cobalt oxide (Lix(NiCo)O ₂ ), lithium nickel cobalt manganese oxide (Lix(NiCoMn)O ₂ ), lithium nickel cobalt aluminum oxides such as Lix(NiCoAl)O ₂ ), spinel-type lithium manganese oxide (LixMn ₂ O ₄ ), or manganese dioxide (MnO ₂ ), or oxides such as lithium iron phosphate (LixFePO ₄ ), or lithium manganese phosphate (LixMnPO ₄ ). It may be an olivine-type compound.

The negative electrode 150 may be an electrode that operates as an anode to release lithium ions to the electrolyte when the battery is discharged and stores reduced lithium atoms by operating as a cathode when the battery is charged. A detailed configuration of the cathode 150 will be described later.

The separator 170 may be a member that prevents electrical contact between the positive electrode 160 and the negative electrode 150 while allowing lithium ions to pass therethrough. In some embodiments, the separator 170 may include a polymer material such as polyethylene or polypropylene having fine pores of a size capable of allowing lithium ions to pass through.

Referring to FIG. 1 , the positive electrode 160, the negative electrode 150, and the separator 170 are basic units constituting the battery 100, and may be referred to as a battery cell 101. The plate-shaped anode 160, the cathode 150, and the separator 170 may be wound while being stacked on each other. By winding the battery cells, since a space consumed for insulation between the plurality of cells is reduced compared to stacking a plurality of cells, the practical energy density of the battery can be increased. A battery cell in a wound state may be referred to as a jelly roll. Jelly rolls can be rolled to have a cylindrical cross section or a stadium shape cross section with a circular cross section. Compared to the cylindrical cross section, the stadium-shaped cross section can increase the efficiency of space use because the thickness and width can be adjusted.

The battery protection member 180 may be a container having an inner space in which the negative electrode 150, the positive electrode 160, and the separator 170 are rolled, folded, or stacked. The battery protection member 180 may include metal (eg, aluminum or stainless steel), a polymer material, or a composite material thereof. In FIG. 1 , the battery protection member 180 is illustrated as a pouch type, but this is exemplary, and the battery protection member 180 may be prismatic (usually referred to as 'prismatic'), cylindrical, or It can have various form factors such as a coin type.

An electrolyte solution (not shown) may be injected into the inside 180 of the battery protection member, and the battery protection member 180 may be sealed. An organic electrolyte may be used as the electrolyte in consideration of the reactivity between water and metal. The organic electrolyte may include a lithium salt and an organic solvent. Lithium salts are LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ , LiN(SO ₂ C ₂ F ₅ ) ₂ , Li(CF ₃ SO 2 ) ₂ N, LiN(SO ₃ C 2 F ₅ ) ₂ , LiC ₄ F ₉ SO ₃ , LiClO ₄ , LiAlO ₂ , LiAlCl ₄ , LiCl, LiI, LiB(C ₂ O ₄ ) ₂ may be one or a mixture thereof.

The organic solvent may include a cyclic carbonate such as ethylene carbonate, butylene carbonate or vinylene carbonate, a linear carbonate such as dimethyl carbonate, methyl ethyl carbonate or diethyl carbonate, or an acetate-based compound such as methyl acetate, ethyl acetate, or propyl acetate. can

2A is a cross-sectional view showing a battery 200 according to embodiments of the present invention.

2B is an enlarged cross-sectional view of a battery 200 according to various embodiments of the present invention.

2C is a schematic diagram showing a laminated structure of a pouch 202 of a battery 200 according to an embodiment of the present invention.

The cross section of FIG. 2A is a cross section of the reference line XX' of FIG. 1 .

FIG. 2B is an enlarged view of area A of FIG. 2A.

Referring to FIGS. 2A , 2B and 2C , a battery 200 may include a battery cell 201 and a pouch 202 . The battery cell 201 (eg, battery cell 101 of FIG. 1 ) includes a positive electrode (eg, positive electrode 160 of FIG. 1 ), a negative electrode (eg, negative electrode 150 of FIG. 1 ) and a separator (eg, separator 170 of FIG. 1 ). )), and they may be stacked to be the smallest unit operable as the battery 200 through an electrochemical reaction. In some embodiments, battery cell 201 may be rolled into a jellyroll. In some embodiments, the battery cell 201 may have a cross section of a shape having at least one flat surface and at least one curved surface, for example, a stadium shape in which both ends of a rectangle are finished with semicircles.

The pouch 202 may include a first polymer layer 210 , a metal layer 232 , a second polymer layer 231 and an adhesive layer 220 .

The first polymer layer 210 may have an inner space 211 in which the battery cell 201 is disposed, and may be a member that surrounds and seals the outside of the battery cell 201 . In some embodiments, the first polymer layer 210 may include a film-like polymer material. The first polymer layer 210 is formed to have at least one inner space 211, and may include a flange portion 212, which is a portion where end portions are joined to each other in order to seal the inner space 211 from the outside. . The polymer material of the first polymer layer 210 may include, for example, a thermoplastic polymer material such as polyolefin, TPU, or PVC. The thermoplastic polymer has advantages in that it can be easily formed and molded, easily joins the flange portion 212 through heat welding, and has high sealing performance in a fused state. The thermoplastic polymer may include cast polypropylene (CPP). The first polymer layer 210 including unstretched polypropylene has excellent sealing strength and low chemical permeability such as oxygen.

The second polymer layer 231 may be a layer that protects the battery 200 from external forces and foreign substances by entirely surrounding the first polymer layer 210 surrounding the battery cell 210 from the outside. The second polymer layer 231 may be a member that has high mechanical strength and protects the battery 200 from external forces. The second polymer layer 231 may include, for example, nylon, ultra high molecular weight polyethylene, PET, PTFE, and/or PEN.

The metal layer 232 may include a thin metal plate laminated and attached to the inner surface of the second polymer layer 231 . The metal layer 232 may reinforce the rigidity of the second polymer layer 231 and increase permeability to external chemicals such as moisture. The metal layer 232 may include a metal having excellent formability and chemical resistance, such as a thin aluminum plate or a thin stainless steel plate. Referring to FIG. 2C , in some embodiments, the metal layer 232 may be attached to the inside of the second polymer layer 231 by a dry lamination layer 233 . A layer composed of the second polymer layer 231 and the metal layer 232 stacked on the second polymer layer 231 may be defined as the outer layer 230 of the pouch.

The adhesive layer 220 is a layer that is positioned between the metal layer 232 and the first polymer layer 210 to mutually adhere a portion of an inner surface of the metal layer 232 and an outer surface of the first polymer layer 210 to each other. can The adhesive layer 220 may include a pressure-sensitive adhesive, a chemically activated adhesive, a heat activated adhesive, a light activated adhesive, or a mixture thereof. In some embodiments, adhesive layer 220 may include a heat activated adhesive. Heat activated adhesives may include materials such as ethylene vinyl acetate or acrylic acid, for example. The heat-activated adhesive is used when the battery 200 undergoes a battery activation step such as heat press charge (HPC) during manufacturing, or when the thermoplastic polymer material of the first polymer layer 210 is heated for fusion. Since it is activated by being heated together at the time of application, there is an advantage in that the manufacturing process of the battery 200 can be simplified without requiring a separate adhesive activation or curing process. In addition, the adhesive layer 220 may be used to mutually bond the outer layer 230 so that the outer layer 230 is closed and completely covers the first polymer layer 210 .

In some embodiments, the first polymer layer 210 includes a curved portion and a flat portion corresponding to the curved and flat surfaces of the battery cell 201, and the adhesive layer 220 is formed with a metal on the flat portion of the first polymer layer 210. Layer 232 may be adhered. When the curved portion is bonded, there is a risk of wrinkles of the outer layer 230 of the pouch 202 or overextension or tearing of the first polymer layer 210 due to the difference in curvature of the curved surface, so the first polymer layer 210 ) and the metal layer 232 are bonded to each other in a flat area except for a curved area, thereby reducing this risk. In addition, since the first polymer layer 210 and the metal layer 232 are adhered to each other in a planar region, it is possible to prevent the first polymer layer 210 from flowing inside the pouch 202 .

In addition, since the outer layer 230 surrounds the first polymer layer 210 in a state in which the first polymer layer 210 has already been molded (eg, formed) to have the inner space 211, the entire pouch 202 No need to mold. Therefore, the second polymer layer 231 and the metal layer 232 of the outer layer 230 do not receive stress due to the molding of the inner space 211, and therefore, the adhesive layer 220 is formed during molding of the conventional pouch. It may not receive interlayer stress. Accordingly, the adhesive layer 220 of the present invention may include an adhesive, such as a pressure sensitive adhesive or a heat activated adhesive, having a lower adhesive strength compared to adhesive means used in conventional composite pouches, such as dry lamination adhesion.

3A is an enlarged cross-sectional view of a battery 200 in accordance with some embodiments of the invention.

3B is an enlarged cross-sectional view comparing a battery 200 according to an embodiment of the present invention and a battery 10 according to a comparative example.

Referring to FIG. 3A , the first polymer layer 210 of the battery 200 may include a flange portion 212 formed by bonding thin polymer materials to seal the inner space 211 . In some embodiments, the flange portion 212 may be formed by heat-sealing the thermoplastic polymer material of the first polymer layer 210 so that the inner space 211 is sealed. The flange portion 212 may be extended to increase a bonding area to secure sufficient sealing performance.

In some embodiments, the flange portion 212 may be bent to abut the outer surface of the first polymer layer 210 . The outer layer 230 of the pouch 202 may be bent to cover the flange portion 212 in contact with the outer surface of the first polymer layer 210 from the outside. The flange portion 212 may be located in an area surrounded by the outer layer 230 . According to an embodiment, an adhesive layer (eg, the adhesive layer 220 of FIG. 2B ) may be positioned between the flange portion 212 and the metal layer 232 .

In some embodiments, the outer layer 230 may be closed to entirely enclose the first polymer layer 210 , thereby protecting the first polymer layer 210 and the battery cell 201 . The adhesive layer 230 extends from the region between the first polymer layer 210 and the outer layer 230 to the region where the outer layer 230 is closed, forming an inner surface of the outer layer 230 (eg metal layer 232). It is possible to close the outer layer 230 by adhering to each other.

Referring to FIG. 3B, the battery 10 according to the comparative example includes a high-strength polymer layer 14, a metal layer 13, and an inner polymer layer 12 that are adhered to each other and stacked by dry lamination. A battery including a single pouch 11 made of a single composite material and sealing an internal space 211 by bonding an inner polymer layer 12, a metal layer 13, and a high-strength polymer layer 14 of the composite material to each other. (10). The pouch 11 according to the comparative example may be sealed by bonding the inner polymer layer 12 . The sealed area (X) is extended to secure sealing performance, and the sealed area (X) is bent to secure structural rigidity.

When the sealed portion (X) of the battery 10 according to the comparative example is bent, the pouch 11 made of a composite material having a multi-layer structure includes not only the inner polymer layer 12 but also the metal layer 13 and the high-strength polymer layer. Since 14 is bent together, there is a risk of causing excessive tensile strain and damage to at least one of the high-strength polymer layer 14 or the metal layer 13 by increasing the bending radius. In addition, since a plurality of layers are disposed in the sealed portion X, the space D1 occupied by the pouch 11 may increase. In order to reduce the space D1 occupied by the pouch 11, the bending process should be made tight, and in this case, tensile strain applied to the high-strength polymer layer 14 and the metal layer 13 may increase.

In contrast, in the pouch 202 according to the embodiment of the present invention, since only the first polymer layer 210 is in charge of sealing, the flange portion 212 made of only the thin first polymer layer 210 is bent and the metal layer 232 ) and the second polymer layer 231. Since the metal layer 232 and the second polymer layer 231 are bonded to only a narrower area than the flange portion 212 to cover the first polymer layer 210, the pouch 11 of the battery 10 according to the comparative example Unlike the sealed portion (X) of the, it is not bent. The first polymer layer 210 according to the embodiment of the present invention is a single layer that is thinner than the pouch of the comparative example, which is a multi-layer composite material, and does not cause excessive elongation during bending, and may include a thermoplastic polymer material such as CPP. The risk of damage can be relatively low due to its excellent flexibility.

In addition, according to the embodiment of the present invention, when only the first polymer layer 210 is sealed and bent to form the flange portion 212, the first polymer layer 210 is thicker than the pouch 11 of the comparative example. Since it is thin, the space D2 occupied by the pouch 202 of the present invention can be reduced. Therefore, the first polymer layer 210 has a large sealing area capable of sufficiently securing sealing performance, and the battery 200 can be miniaturized.

4A is a perspective view of a battery 200 according to another embodiment of the present invention.

4B is a cross-sectional view of a battery 200 according to another embodiment of the present invention.

4C is an enlarged cross-sectional view of a battery 200 according to another embodiment of the present invention and a battery 10 according to a comparative example.

4D is an internal perspective view of a battery 200 according to another embodiment of the present invention.

The cross section of FIG. 4B is a cross section of the reference line XX' of FIG. 4A.

An embodiment of the present invention shown in FIG. 4c is an enlarged cross-sectional view of area A of FIG. 4b.

4A and 4B, the battery 200 includes a plurality of battery cells 201a and 201b, and the first polymer layer 210 has a plurality of battery cells 201a and 201b respectively positioned and each A plurality of inner spaces 211a and 211b sealing the battery cells 201 may be provided. The battery 200 may include a plurality of cells in order to overcome the size limit of a single battery cell 201, the limit of charge/discharge speed and efficiency, or the limit of output. When the battery 200 includes a plurality of battery cells 201a and 201b, each battery cell 201a and 201b may need to be individually sealed to prevent a short circuit between electrodes. The first polymer layer 210 may individually seal each battery cell 201 by having a plurality of inner spaces 211a and 211b. The second polymer layer 231 and the metal layer 232 of the outer layer 230 may entirely cover the outside of the first polymer layer 210 having the plurality of inner spaces 211a and 211b.

In some embodiments, the first polymer layer 210 may include a segment portion 213 that is a region in which polymer materials are mutually bonded to divide the plurality of internal spaces 211a and 211b. The segmental portion 213 may be formed by bonding regions of the first polymer layer 210 facing each other between the plurality of battery cells 201a and 201b.

Referring to FIG. 4C , the battery 10 according to the comparative example is a composite material including a high-strength polymer layer 14, a metal layer 13, and an inner polymer layer 12 that are laminated by being adhered by dry lamination. The branch is a battery 10 including a plurality of battery cells individually sealed by the pouch 11 . In the battery 10 according to the comparative example, the pouches 11 surrounding each battery cell are individually bonded, sealed, and bent, and the sealed and bent areas of the pouches 11 are disposed to face each other in an adjacent area (Y area). ) may be included.

In the battery 10 according to the comparative example, the sealed portion of the pouch 11 may be bent to secure structural rigidity of the sealed portion. When bending it, the pouch 11 made of a composite material having a multi-layer structure is bent not only with the inner polymer layer 12 but also with the metal layer 13 and the high-strength polymer layer 14, so that the bending radius increases, resulting in high strength. There is a risk of causing excessive tensile strain and damage to at least one of the polymer layer 14 or the metal layer 13 . In addition, since a plurality of layers are disposed in the region Y adjacent to each pouch 11 , the distance D3 between the battery cells in the sealed region may increase. Accordingly, the size of the battery can be increased. In order to reduce the gap D3 between the battery cells, the bending process should be made tight, and in this case, tensile strain applied to the high-strength polymer layer 14 and the metal layer 13 may increase.

In the battery 200 according to the embodiment of the present invention, the plurality of battery cells 201a and 201b are separated and sealed from each other by the segmental portion 213 of the first polymer layer 210, and the first polymer layer 210 ) is relatively thin and has high flexibility, enabling tight bending. Accordingly, the space D4 between the plurality of battery cells 201a and 201b is reduced, thereby reducing the size and volume of the battery 200 having the plurality of battery cells 201a and 201b. A value obtained by dividing the capacity of the battery 200 by the volume of the entire assembled battery 200 may be defined as the volumetric energy density of the entire battery, and in embodiments of the present invention, the volume of the entire battery 200 The volumetric energy density can be improved by reducing

Also, referring back to FIG. 4B , the battery 200 according to the embodiment of the present invention has a plurality of battery cells 201a and 201b at an end portion in the opposite direction to the direction in which they face each other (region B in FIG. 4A ), FIG. As shown in FIG. 3B , the flange portion 212 formed by bonding and sealing the first polymer layer 210 may be bent and positioned within an area surrounded by the external pouch 230 . As described with reference to FIG. 3B , the above configuration may occupy less space than the space occupied by the battery 10 of the comparative example by bonding and sealing the pouch 11 . Therefore, the overall volumetric energy density of the battery 200 of the present invention can be further improved.

Referring to FIG. 4D , the battery 200 according to another embodiment of the present invention has a length shorter than the first battery cell 201a and the first battery cell 201a and is parallel to the first battery cell 201a. It may include second battery cells 201b that are arranged in an optimal manner. The battery 200 may have an L-shape or a T-shape as a whole.

When arranging internal components of the electronic device, since the battery 200 has an L-shaped or T-shaped shape, the degree of freedom in arranging internal components can be improved and the internal space of the electronic device can be efficiently utilized. In addition, it may be easy to design by separating the battery 200, which is vulnerable to heat, from high-heating components (eg, components such as an AP and a camera of an electronic device). Since the jelly roll is manufactured by winding electrode plates stacked in a plate shape, it is difficult to manufacture a shape such as an L or T shape with only one battery cell 201 . Accordingly, the L-shaped or T-shaped battery 200 may be manufactured by arranging a plurality of jelly roll-type battery cells 201a and 201b having different lengths.

When a plurality of jelly-roll-type battery cells are individually inserted into and sealed into a pouch and disposed inside the electronic device as in the comparative example (eg, the battery 10 according to the comparative example of FIG. 4C), the pouch is bonded as described above. Since the thickness of the part is excessive, the space between the jelly rolls is excessive, and the volumetric energy density of the entire battery may be reduced. In contrast, according to embodiments of the present invention, since the plurality of jelly rolls are separated by the segmented portion 213 of the first polymer layer 210, the space between the jelly rolls is reduced in the battery 200 according to the embodiments of the present invention. ), it is possible to efficiently utilize the internal space of the electronic device while improving the volumetric energy density.

5A is a cross-sectional view of a battery 200 in accordance with some embodiments of the invention.

5B is an enlarged cross-sectional view illustrating a battery 200 according to an embodiment of the present invention and a battery 200 according to a comparative example.

5C is an internal perspective view showing a battery 200 according to another embodiment of the present invention.

Referring to FIG. 5A , a battery 200 according to some embodiments of the present invention includes a plurality of battery cells 201a and 201b stacked in a vertical direction with respect to the plane of the battery cell 201 and stacked battery cells ( 201) may include a plurality of first polymer layers 210 that are stacked while wrapping and sealing each of them. External surfaces of each of the stacked first polymer layers 210a and 210b may be bonded to each other in an area where the plurality of first polymer layers 210 overlap. The outer layer 230 (eg, the metal layer 232 and the second polymer layer 231 ) of the pouch 202 may entirely cover the stacked plurality of first polymer layers 210 from the outside. The battery 200 may include a plurality of battery cells 201a and 201b to overcome the limitations of the size of the single battery cell 201, the limitations of charging and discharging speed and efficiency, and the limitations of output, and reduce the mounting area. can be stacked in a vertical direction. When the battery 200 includes a plurality of battery cells 201a and 201b, each battery cell 201 may need to be individually sealed to prevent a short circuit between electrodes. The plurality of first polymer layers 210 may individually seal the plurality of battery cells 201a and 201b.

The outer layer 230 may entirely cover the outside of the plurality of first polymer layers 210 and be closed. In the region where the outer layer is closed, the auxiliary adhesive layer 221 may close the outer layer 230 by adhering the inner surface (eg, the metal layer 232) of the outer layer 230 to each other. For the auxiliary adhesive layer 221, the description of the adhesive layer 220 may be referred to unless contradictory.

Referring to FIG. 5B , the battery 10 according to the comparative example is individually formed by a pouch 11 having one composite material including a high-strength polymer layer 14, a metal layer 13, and an inner polymer layer 12. A battery including a plurality of battery cells that are sealed and stacked.

In the battery 10 according to the comparative example, since the pouches 11 made of a composite material having a multi-layer structure surround each battery cell, the pouches 11 made of the composite material are double-stacked so that the space D5 between the battery cells is formed. can increase Thus, the overall thickness of the battery can be increased. In order to reduce the space D5 between the battery cells, the thickness of the pouch 11 needs to be thinned, and in this case, the strength of the pouch is weakened, which may increase the risk of damage to the battery.

In the battery 200 according to an embodiment of the present invention, the plurality of battery cells 201a and 201b are separated and sealed from each other by a plurality of first polymer layers 210a and 210b, and the first polymer layer 210 is Since it is relatively thinner than the pouch 11 made of a composite material, the space D6 between the plurality of battery cells 201a and 201b is reduced to reduce the overall thickness of the battery 200 having the plurality of battery cells 201a and 201b. can be reduced Accordingly, the volumetric energy density of the entire battery 200 may be improved. In some embodiments, even if the thickness of the first polymer layer 210, the second polymer layer 231, and/or the metal layer 232 constituting the pouch 202 is relatively increased compared to the comparative example, a substantial volume The safety of the battery 200 can be improved without increasing and decreasing the volumetric energy density. In addition, when the first polymer layer 210 includes a thermoplastic polymer and the overlapping region of the plurality of first polymer layers 210 is bonded through fusion, in order to fix the plurality of battery cells 201a and 201b to each other Since there is no need for a separate bonding layer to exist, the thickness can be further reduced. In addition, since heat fusion between the plurality of first polymer layers 210 can be performed together in a heating process such as the HPC described above when manufacturing the battery 200, the battery 200 manufacturing time and number of processes can be reduced. there is.

In addition, as shown in FIG. 3B, the first polymer layers 210a and 210b of the battery 200 of the present invention are bonded to form flange portions 212a and 212b, respectively, and the flange portions 212a and 212b are By being bent and located inside the outer layer 230, the volumetric energy density of the entire battery 200 can be further improved.

Referring to FIG. 5C , a battery 200 according to another embodiment of the present invention has a first battery cell 201a and a smaller size than the first battery cell 201a, and a flat surface of the first battery cell 201a. It may include second battery cells 201b stacked vertically with respect to the direction.

When arranging the internal components of the electronic device, if the batteries 200 having different sizes are stacked vertically, the degree of freedom in arranging the internal components can be improved and the internal space of the electronic device can be efficiently utilized.

When a plurality of jelly rolls are individually inserted into a pouch and sealed and stacked, as described above, since the thickness of the pouch is excessive, the space D1 between the battery cells 201 is excessive, and the volume energy of the entire battery 200 Density may be reduced. In contrast, according to embodiments of the present invention, in the battery 200, since the plurality of jelly rolls are separated by the segmental portions 213 of the first polymer layer 210, the space between the battery cells 201 is reduced. The size of the battery 200 may be reduced and the internal space of the electronic device may be efficiently utilized while volumetric energy density is improved.

The battery 200 according to various embodiments of the present invention includes a positive electrode 160, a negative electrode 150, and a separator 170 separating the positive electrode 160 and the negative electrode 150, and has at least one flat and It includes a battery cell 201 having a shape including at least one curved surface, and a pouch 202 surrounding the outside of the battery cell 201, wherein the pouch 202 includes at least one battery cell 201, each of which is located. A first polymer layer 210 formed to have one inner space 211 and including a polymer film that seals each of the battery cells 201 and surrounds the outside of each of the battery cells 201, the first polymer layer 210 of the second polymer layer 231, which entirely surrounds the outside of and has higher strength and rigidity than the first polymer layer 210, and a metal material laminated and attached on the inner surface of the second polymer layer 231. Located between the metal layer 232 including the thin plate, the inner surface of the metal layer 232 and the first polymer layer 210, the inner surface of the metal layer 232 and the inner surface of the first polymer layer 210 It may include an adhesive layer 220 that partially adheres to each other. In some embodiments, the battery cell 201 is a jelly roll in which the positive electrode 160, the negative electrode 150, and the separator 170 are stacked on each other in a shape having at least one flat surface and a curved surface. ) can be. In some embodiments, the adhesive layer 220 may include a heat activated adhesive.

In some embodiments, the first polymer layer 210 may include a thermoplastic polymer material. In some embodiments, the thermoplastic polymer material may include cast polypropylene (CPP).

In some embodiments, the first polymer layer 210 includes a flange portion 212 in which the thin-film polymer materials are bonded to each other so that the inner space 211 is sealed against the outside, and the flange portion 212 includes the first It may be bent to face the outer surface of the polymer layer 210 and positioned inside the metal layer 232 . In some embodiments, the first polymer layer 210 includes at least one flat portion and at least one curved portion, and the adhesive layer 220 faces the flat portion and the flat portion of the first polymer layer 210. Areas of the inner surface of the metal layer 232 may be bonded to each other.

In some embodiments, a plurality of battery cells 201a and 201b are arranged in parallel in a horizontal direction with respect to the plane of the battery cell 201, and the first polymer layer 210 includes a plurality of battery cells 201a. , 201b) may be located, and may include a plurality of inner spaces 211a and 211b) separated from each other. In some embodiments, the first polymer layer 210 may include a segment portion 213 that is a region where the polymer materials are mutually bonded to divide the plurality of internal spaces 211a and 211b. In some embodiments, the plurality of battery cells 201a and 201b may include a first battery cell 201a and a second battery cell 201b having a relatively smaller size than the first battery cell 201a. there is.

In some embodiments, a plurality of battery cells 201a and 201b stacked in a vertical direction with respect to the plane of the battery cell 201, and a plurality of battery cells 201a and 201b respectively wrapped around and stacked. It includes the first polymer layers 210a, 210b, 210, and the metal layer 232 and the second polymer layer 231 may completely cover the stacked plurality of first polymer layers 210a, 210b from the outside. there is.

In some embodiments, the plurality of first polymer layers 210a and 210b may be bonded to each other in regions where the plurality of first polymer layers 210a and 210b are stacked and overlap each other. In some embodiments, the plurality of battery cells 201a and 201b may include a first battery cell 201a and a second battery cell 201b having a relatively smaller size than the first battery cell 201a. there is.

A battery pouch 202 according to another embodiment of the present invention includes a positive electrode 160, a negative electrode 150, and a separator 170 separating the positive electrode 160 and the negative electrode 150 and has at least one flat surface. And in the pouch 202 of the battery including the battery cell 201 having a shape including at least one curved surface, the battery cell 201 is molded to have at least one inner space 211 in which each is located. A first polymer layer 210 that is bonded to seal each of the battery cells 201 and surrounds the outside of each battery cell 201 and includes a polymer thin film, and a first polymer layer that entirely surrounds the outside of the first polymer layer 210 A metal layer 232 including a second polymer layer 231 having higher strength and rigidity than that of 210, and a thin plate of metal material laminated and attached on the inner surface of the second polymer layer 231 , Adhesive layer 220 located between the inner surface of the metal layer 232 and the first polymer layer 210, and bonding the inner surface of the metal layer 232 and a part of the inner surface of the first polymer layer 210 to each other. can include In some embodiments, the first polymer layer 210 may include a thermoplastic polymer material. In some embodiments, the thermoplastic polymer material may include cast polypropylene (CPP).

In some embodiments, the first polymer layer 210 includes a flange portion 212 in which the polymer materials on the thin film are bonded to each other so that the inner space 211 is sealed, and the flange portion 212 includes the first polymer layer ( 210 may be bent to face the outer surface of the metal layer 232 and positioned inside the region surrounded by the metal layer 232 . In some embodiments, the first polymer layer 210 includes at least one planar portion and at least one curved portion, and the adhesive layer 220 includes the planar portion of the first polymer layer and a metal layer facing the planar portion ( 232) may be glued together.

In some embodiments, the first polymer layer 210 has a plurality of internal spaces 211a and 211b separated from each other, and a segment in which the polymer material is mutually bonded to divide the plurality of internal spaces 211a and 211b. may include section 213 . In some embodiments, the first polymer layer 210 includes a plurality of first polymer layers 210a, 210b 210 stacked, the plurality of first polymer layers 210a, 210b comprising the plurality of first polymer layers 210a, 210b. The first polymer layers 210a and 210b may be laminated and bonded to each other in an overlapping region.

In addition, the embodiments disclosed in this document disclosed in the specification and drawings are only presented as specific examples to easily explain the technical content according to the embodiment disclosed in this document and help understanding of the embodiment disclosed in this document. It is not intended to limit the scope of the examples. Therefore, the scope of various embodiments disclosed in this document is that all changes or modified forms derived based on the technical ideas of various embodiments disclosed in this document, in addition to the embodiments disclosed herein, are included in the scope of various embodiments disclosed in this document. should be interpreted

200: battery
201: battery cell
201a: first battery cell
201b: second battery cell
210: first polymer layer
211: inner space
212: flange part
213 segmentation
220: adhesive layer
230: outer layer
231 second polymer layer
232: metal layer
233: DL layer

Claims (20)

in the battery,
A battery cell including a positive electrode, a negative electrode, and a separator separating the positive electrode and the negative electrode, and having a shape including at least one flat surface and at least one curved surface; and
Including a pouch surrounding the outside of the battery cell,
The pouch,
a first polymer layer formed to have at least one inner space where each of the battery cells is located and including a polymer film that seals each of the battery cells and surrounds the outside of each of the battery cells;
a second polymer layer entirely surrounding the outside of the first polymer layer and having higher strength and rigidity than the first polymer layer;
a metal layer including a thin plate of a metal material laminated and attached to the inner surface of the second polymer layer;
An adhesive layer disposed between the inner surface of the metal layer and the first polymer layer, and bonding the inner surface of the metal layer and a part of the inner surface of the first polymer layer to each other. According to claim 1,
The battery cell is a jelly-roll battery in which the positive electrode, the negative electrode, and the separator in the form of plates stacked on each other are wound into a shape having at least one flat surface and a curved surface. According to claim 1,
The battery of claim 1, wherein the adhesive layer includes a heat activated adhesive. According to claim 1,
The battery of claim 1 wherein the first polymer layer includes a thermoplastic polymer material. According to claim 4,
The thermoplastic polymer material is a battery containing CPP (Cast PolyPropylene). According to claim 1,
The first polymer layer includes a flange portion in which the polymer materials on the thin film are bonded to each other so that the inner space is sealed against the outside,
The flange portion is bent to face the outer surface of the first polymer layer and is located inside the metal layer. According to claim 1,
the first polymer layer includes at least one planar portion and at least one curved portion;
The adhesive layer bonds the planar portion of the first polymer layer and the region of the inner surface of the metal layer facing the planar portion to each other. According to claim 1,
Including a plurality of the battery cells arranged in parallel in a horizontal direction with respect to the plane of the battery cells,
The first polymer layer includes a plurality of internal spaces in which a plurality of the battery cells are respectively located and separated from each other. The battery according to claim 8, wherein the first polymer layer includes a segment portion that is a region in which the polymer material is mutually bonded to divide the plurality of internal spaces. According to claim 8,
The plurality of jelly rolls include a first battery cell and a second battery cell having a relatively smaller size than the first battery cell. According to claim 1,
a plurality of battery cells stacked in a vertical direction with respect to a plane of the battery cells; and
It includes a plurality of first polymer layers stacked and surrounding each of the plurality of stacked battery cells,
The battery of claim 1 , wherein the metal layer and the second polymer layer entirely surround the stacked plurality of first polymer layers from the outside. According to claim 11,
The plurality of first polymer layers are bonded to each other in regions where the plurality of first polymer layers are stacked and overlap each other. According to claim 11,
The plurality of battery cells include a first battery cell and a second battery cell having a relatively smaller size than the first battery cell. In the battery pouch including a battery cell including a positive electrode, a negative electrode, and a separator separating the positive electrode and the negative electrode and having a shape including at least one flat surface and at least one curved surface,
a first polymer layer formed to have at least one inner space in which each of the battery cells is located, bonded to seal each of the battery cells, and including a polymer thin film surrounding the outside of each of the battery cells;
a second polymer layer entirely surrounding the outside of the first polymer layer and having higher strength and rigidity than the first polymer layer;
a metal layer including a thin plate of a metal material laminated and attached to the inner surface of the second polymer layer;
An adhesive layer disposed between the inner surface of the metal layer and the first polymer layer and bonding the inner surface of the metal layer and a part of the inner surface of the first polymer layer to each other. 15. The method of claim 14,
The first polymer layer is a pouch for a battery comprising a thermoplastic polymer material. According to claim 15,
The thermoplastic polymer material is a pouch for a battery containing CPP (Cast PolyPropylene). 15. The method of claim 14,
The first polymer layer includes a flange portion in which the polymer materials on the thin film are bonded to each other so that the inner space is sealed,
The flange portion is bent to face the outer surface of the first polymer layer and is positioned inside a region surrounded by the metal layer. 15. The method of claim 14,
the first polymer layer includes at least one planar portion and at least one curved portion;
The adhesive layer adheres the flat portion of the first polymer layer and the area of the inner surface of the metal layer facing the flat portion to each other. 15. The method of claim 14,
The first polymer layer,
a plurality of the inner spaces separated from each other; and
A pouch for a battery comprising a segmented portion, which is a region in which the polymer material is mutually bonded to divide the plurality of internal spaces. 15. The method of claim 14,
The first polymer layer includes a plurality of stacked first polymer layers, and the plurality of first polymer layers are bonded to each other in a region where the plurality of first polymer layers are stacked and overlapped.

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