KR20240015546A - Battery comprising safety functional layer - Google Patents

Abstract

A battery comprising a safety function layer is disclosed. A battery according to various embodiments of the present invention includes a battery case that separates the inside and outside of the battery, at least one positive electrode located inside the battery case, and at least one positive electrode located inside the battery case to face the positive electrode. It may include an electrode assembly including a cathode and at least one separator disposed between the anode and the cathode. The anode may include an anode safety functional layer disposed in an area including an outermost anode area, which is the area closest to the inside of the battery case among the anodes.

Description

Battery comprising a safety function layer {BATTERY COMPRISING SAFETY FUNCTIONAL LAYER}

Various embodiments disclosed herein relate to batteries, and more particularly, to batteries that include a safety function layer.

Due to the development of portable electronic devices and electric vehicles, batteries that can store and output electrical energy are being widely used. Lithium-ion batteries are secondary batteries that are lightweight, have high energy density, and have good charge/discharge characteristics and are widely used in fields such as portable electronic devices, electric vehicles, and power storage systems (ESS). A lithium-ion battery has a negative electrode that releases lithium ions into the electrolyte when discharging, a positive electrode that accepts lithium ions released from the negative electrode in an oxidized state during discharge, and a direct contact between the negative electrode and the positive electrode. Includes a separator.

Lithium-ion batteries can suffer various types of damage, such as external pressure, impact, and/or puncture. Due to the above-mentioned damage, heat generation, ignition, or thermal runaway may occur due to a short current when the cathode and anode come into contact with each other, or a fire may occur due to a reaction of the anode and/or cathode active material. Various safety measures are being taken to reduce the risk of fire in lithium-ion batteries.

To reduce the risk of fire, the battery's anode may include various layers of anode safety features. Additionally, the battery's cathode may include various cathode safety feature layers. However, by including the anode safety function layer and/or the cathode safety function layer, the volume of the overall cell including the anode and cathode increases, and thus the power density and energy density of the battery may decrease. Additionally, some bipolar safety functional layers may increase internal resistance, causing a further reduction in power density.

Various embodiments disclosed in this document can provide a battery with improved safety and energy density.

A battery according to various embodiments of the present invention includes a battery case that separates the inside and outside of the battery, at least one positive electrode located inside the battery case, and at least one positive electrode located inside the battery case to face the positive electrode. It may include an electrode assembly including a cathode and at least one separator disposed between the anode and the cathode. The anode may include an anode safety functional layer disposed in an area including an outermost anode area, which is the area closest to the inside of the battery case among the anodes.

In various embodiments, the battery is a winding type battery in which the electrode assemblies are wound so as to overlap each other, and the anode, the cathode, and the separator may be wound so that the outermost anode region is located toward the outside of the battery.

In various embodiments, the anode safety functional layer extends from the outermost anode region among the anodes to at least a portion of an inner anode region, which is an area wrapped in a space located in the interior direction of the battery, and the anode safety functional layer includes, Among the anodes, the thickness of the anode safety functional layer disposed in the outermost anode region may be thicker than the thickness of the anode safety functional layer extended to the inner anode region.

In various embodiments, the thickness of the anode safety function layer may gradually decrease toward the interior of the battery.

In various embodiments, the thickness of the anode safety function layer may continuously decrease toward the interior of the battery.

In various embodiments, the battery is a stacked battery including a plurality of anodes, a plurality of cathodes, and a plurality of separators that are alternately stacked,

The outermost anode region may be anodes located on the highest and lowest layers among the plurality of stacked anodes.

In various embodiments, the anode safety function layer is further disposed on at least a portion of an inner anode region that is anodes stacked between the outermost anode regions, and the anode safety function layer is located on the outermost anode region among the anodes. The thickness of the anode safety function layer disposed may be thicker than the thickness of the anode safety function layer disposed in the internal anode region.

In various embodiments, the thickness of the anode safety function layer may gradually decrease toward the interior of the battery.

In various embodiments, the positive electrode includes a positive electrode current collector and a positive electrode active material located on a surface of the positive electrode current collector,

The positive electrode safety function layer may be located between the positive electrode current collector and the positive electrode active material.

In various embodiments, the positive electrode includes the positive electrode current collector and a positive electrode active material located on a surface of the positive electrode current collector,

The positive electrode safety function layer may coat the surface of the positive electrode active material.

In various embodiments, the anode safety functional layer may include a positive temperature coefficient (PTC) material.

In various embodiments, the PTC material may include a polymer composite.

In various embodiments, the anode safety functional layer may include a phosphate-based olivine material.

In various embodiments, a short-circuit protection layer is disposed inside the battery casing, spaced apart from the outermost anode region and surrounding at least a portion of the outer peripheral surface of the outermost anode region, is electrically connected to the cathode, and has a conductive material. may include.

In various embodiments, the width of the short-circuit protection layer may be narrower than the width of the outermost anode region.

In various embodiments, a battery of batteries further comprising a cathode safety function layer formed in an area of the cathode corresponding to an area of the anode where the anode safety function layer is disposed.

A battery according to various embodiments of the present invention includes a battery casing that separates the inside and outside of the battery, at least one positive electrode located inside the battery casing, and at least one positive electrode located inside the battery casing to face the positive electrode. It may include a cathode, at least one separator disposed between the anode and the cathode, and a safety function layer disposed on at least one of the anode or the cathode. The thickness of the safety function layer may increase as it is located relatively close to the outside of the battery.

In various embodiments, the safety functional layer is disposed on the anode and may include a positive temperature coefficient (PTC) material.

In various embodiments, the PTC material may include a polymer composite.

In various embodiments, the safety function layer is disposed on the anode and may include a phosphate-based olivine material.

According to various embodiments disclosed in this document, the anode safety function layer is disposed in an area located close to the case (or pouch) of the battery, thereby improving safety against penetration from the outside and increasing energy density and power density. Improved batteries may be provided.

In relation to the description of the drawings, identical or similar reference numerals may be used for identical or similar components.
1A schematically shows the structure of a battery according to various embodiments.
Figure 1B schematically shows the structure of a battery according to various embodiments.
Figure 1C schematically shows the structure of a battery according to various embodiments.
FIG. 2A is a schematic diagram showing a cross section of a stack-type battery according to various embodiments.
Figure 2b is a schematic diagram showing a cross section of a winding-type battery according to various embodiments.
FIG. 2C is a diagram showing the wound components of FIG. 2B in an unwound state.
3A to 3C are enlarged cross-sectional views showing the outermost anode area of a battery according to various embodiments.
4A to 4D are cross-sectional views showing batteries according to various embodiments.
Figure 5 is a cross-sectional view showing a battery according to various embodiments.

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

Reference signs for elements in the drawings refer to the same elements throughout the drawings. Additionally, as used herein, the term “and/or” includes any one and all combinations of one or more of the corresponding 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 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 disclosure more faithful and complete, and to fully convey the spirit of the invention to those skilled in the art.

The terms used herein are used to describe examples and are not intended to limit the scope of the invention. In addition, even if described in the specification as a singular number, plural forms may be included unless the context clearly indicates singularity. Additionally, as used herein, the terms "comprise" and/or "comprising" specify the presence of stated features, numbers, steps, operations, members, elements and/or groups thereof. It does not exclude the presence or addition of other shapes, numbers, movements, members, elements and/or groups. Additionally, for those skilled in the art, a structure or shape disposed “adjacent” to another shape may have a portion that overlaps or is disposed beneath the adjacent shape.

As used herein, “below,” “above,” “upper,” “lower,” “horizontal,” or “vertical.” Relative terms such as may be used to describe the relationship that one component, layer or region has with another component, layer or region, as shown in the drawings. It should be understood that these terms encompass not only the directions indicated in the drawings, but also other directions.

1A to 1C schematically show the structure of a battery according to various embodiments.

1A to 1C, the battery 100 (e.g., a stacked battery 100a, a cylindrical battery 100b, or a jelly roll battery 100c) has a positive electrode 160 and a negative electrode 150. ) (negative electrode) and a separator (170). The anode 160 operates as a cathode when the battery 100 is discharged and absorbs lithium ions from the electrolyte contained in the battery 100 to form a lithium compound. When the battery 100 is charged, the anode 160 operates as an anode. It may be an electrode that emits lithium ions. The positive electrode may include, for example, a positive electrode current collector including a thin metal plate such as aluminum, and a positive electrode active material. The positive electrode active material is a lithium compound, such as 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 oxide (Lix(NiCoAl)O ₂ ), spinel-type lithium manganese oxide (LixMn ₂ O ₄ ), manganese dioxide (MnO ₂ ), lithium iron phosphate (LixFePO ₄ ) and/or lithium manganese phosphate (LixMnPO ₄ ). It may include olivine-type compounds such as.

The cathode 150 operates as an anode when discharging the battery 100, releasing lithium ions to the electrolyte contained in the battery 100, and operates as a cathode when charging, producing reduced lithium atoms. It may be an electrode that stores . The negative electrode 150 may include, for example, a negative electrode current collector including a thin metal plate such as copper, and a negative electrode active material. Negative active materials include, for example, artificial and/or natural graphite that stores lithium by intercalation, various silicon-based compounds such as silicon oxide, silicon nitride, and/or silicon carbide, and/or lithium metal that stores lithium on metal. Or, it may include various alloys or metal compounds thereof.

The separator 170 may be a member that prevents electrical contact between the anode 160 and the cathode 150 while allowing lithium ions to pass through. In some embodiments, the separator 170 may include a polymer material such as polyethylene or polypropylene that has micropores large enough to allow lithium ions to pass through. The smallest unit of the battery 100 including the cathode 150, the anode 160, and the separator 170 may be referred to as an electrode assembly.

The battery case 180 (e.g., battery case 180a, battery case 180b, or battery case 180c) accommodates the cathode 150, the anode 160, and the separator 170 by being wound, folded, or laminated. It can be a container with an internal space that is For example, the battery casing 180 may include metal (eg, aluminum or stainless steel), polymer materials, and/or composites or laminates thereof. An organic electrolyte (not shown) may be injected into the battery casing 180 and sealed. For example, the organic electrolyte solution may include a lithium salt and an organic solvent. Lithium salts include LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ , LiN(SO ₂ C ₂ F ₅ ) ₂ , Li(CF3SO ₂ ) ₂ N, LiN(SO ₃ C2F ₅ ) ₂ , LiC4F9SO3, LiClO4, LiAlO2, LiAlCl4 , LiCl, LiI and LiB(C2O4)2 or mixtures thereof. For example, the organic solvent may be 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, an acetate such as methyl acetate, ethyl acetate, or propyl acetate. It may include compounds and fluorinated organic compounds in which at least one hydrogen atom thereof is replaced with fluorine (F).

Referring to FIG. 1A , the battery 100 according to various embodiments may be a stack type battery 100a in which at least one electrode assembly is stacked and located in the internal space of the battery case 180a. The battery case 180a may be, for example, a square can or a soft pouch.

Referring to FIG. 1B, the battery 100 according to various embodiments may be a cylindrical battery 100b in which at least one electrode assembly is wound and located in the internal space of the battery case 180b. The battery case 180b may be, for example, a cylindrical or similar pillar-shaped can.

Referring to FIG. 1C, the battery 100 according to various embodiments is a jelly-roll type in which at least one electrode assembly is wound into a stadium-shaped cross section and located in the inner space of the battery case 180c. type) It may be a battery (100c). The battery case 180c may be, for example, a square can or a soft pouch. The cylindrical battery 100b and the jelly roll-type battery 100c share the characteristic that the battery cells are wound and located inside the battery cases 180b and 180c, so they are collectively called 'winding-type' batteries. It can be referred to as (100b, 100c).

FIG. 2A is a schematic diagram showing a cross section of a stacked battery 200a according to various embodiments.

Figure 2b is a schematic diagram showing a cross section of a winding-type battery 200b according to various embodiments.

FIG. 2C is a diagram showing the wound components of FIG. 2B in an unwound state.

The cross section in FIG. 2A may be, for example, a cross section in the A-A' direction of FIG. 1A.

The cross section in FIG. 2B may be, for example, a cross section in the B-B' direction of FIG. 1B.

Referring to FIG. 2A, the stacked battery 200a (e.g., the stacked battery 100a of FIG. 1A) has a plate shape and includes at least one cathode 220, at least one separator 230, and It may include at least one anode 210. Among at least one anode 210, the area of the anode 210 closest to the outside of the stacked battery 200a (e.g., the area located in the direction indicated by EX in FIG. 2A) is referred to as the 'outermost anode area 210a'. can be defined. For example, in the stacked battery 200a, the one closest to the outside among the stacked plate-shaped anodes 210, for example, the one located on the uppermost and lowermost layers of the stacked anodes 210 is called the outermost anode region 210a. can be defined. In the stacked battery 200a, the anode 210 stacked between the outermost anode regions 210a may be defined as the inner anode region 210b. The detailed configuration of the anode 210 will be described later.

Referring to FIGS. 2B and 2C, the winding-type battery 200b (e.g., the winding-type battery 100b, 100c in FIGS. 1B or 1C) has a plate shape and includes a cathode 220, a separator 230, and a cathode 220 sequentially stacked on each other. Including the anode 210, the cathode 220, separator 230, and anode 210 may be wound in a spiral shape to form a structure in which they overlap from the center outward (for example, in the direction indicated by EX in FIG. 2B). Among the anodes 210, the area of the anode 210 closest to the outside of the battery (for example, the direction indicated by EX in Figure 2b) may be defined as the 'outermost anode area 210a', and the winding type battery 200b In , the outermost wound area may be defined as the outermost anode area 210a. In the winding type battery 200b, the area wound inside the outermost anode area 210a may be defined as the inner anode area 210b.

2B and 2C show only a cylindrical one (for example, the cylindrical battery 100b of FIG. 1B) among the winding-type batteries 200b. However, description of the winding-type battery 200b according to various embodiments of the present disclosure. It will be apparent to those skilled in the art that it can be applied not only to cylindrical batteries but also to jelly-roll-type batteries (for example, the jelly-roll-type battery 100c of FIG. 1C).

2A to 2C, the anode 210 may include an anode safety function layer 213 disposed at least in the outermost anode region 210a of the anode 210. When the anode safety function layer 213 is damaged by factors such as penetration and/or pressure from the outside, the cathode 220 of the battery is made of a cathode active material (e.g., the cathode active material 212 in FIG. 3A) to be described later. And/or it may be a member that reduces the risk of fire or other unsafe situations by directly contacting the positive electrode current collector (e.g., the positive electrode current collector 211 of FIG. 3A). In various embodiments, the anode safety function layer 213 may be disposed in regions of the anode 210 that include the outermost anode region 210a as well as other regions. This will be described later.

Within the battery 200 (e.g., battery 200a or battery 200b), an area where there is a relatively high risk of damage due to penetration and/or pressurization is an area close to the outside of battery 200, The anode safety function layer 213 is disposed at least in the outermost anode region 210a of the anode 210, thereby effectively reducing the risk of damage from the outside. In addition, the energy density of the battery resulting from the anode 210 including the anode safety function layer 213 is not disposed or less of the anode safety function layer 213 is disposed in the internal anode region 210b. and/or reduce adverse effects on power density.

2A to 2C, in various embodiments, the cathode 220 is a cathode safety function layer disposed in an area of the cathode 220 that corresponds to an area of the anode 210 where the anode safety function layer 213 is disposed. It may include (223).

3A to 3C are enlarged cross-sectional views showing the outermost anode area of a battery according to various embodiments.

3A to 3C, the positive electrode 210 (e.g., the positive electrode 160 of FIGS. 1A to 1C) of a battery (e.g., battery 100 or battery 200) includes a positive electrode current collector 211, It may include a positive electrode active material 212 and a positive electrode safety function layer 213.

The positive electrode current collector 211 may be a member that collects charges generated by the positive electrode active material 212 and supplies power to the outside of the battery, or may receive power from the outside to charge the battery. In various embodiments, the current collector may include a plate-shaped metal, particularly a metal such as aluminum, which has high electrochemical stability in the electrode reaction potential region of the positive electrode active material 212.

The positive electrode active material 212 may be positioned at least partially in contact with the surface of the positive electrode current collector 211 as shown in FIG. 3B or may be positioned spaced apart from the positive electrode current collector 211 as shown in FIG. 3A. The positive electrode active material 212 may be a material that accepts lithium ions transferred through the electrolyte from the negative electrode 220 (eg, the negative electrode 150 in FIGS. 1A to 1C) during discharge. The positive electrode active material 212 is, for example, 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 ), Such as lithium nickel cobalt aluminum oxide (Lix(NiCoAl)O ₂ ), spinel-type lithium manganese oxide (LixMn ₂ O ₄ ), manganese dioxide (MnO ₂ ), lithium iron phosphate (LixFePO ₄ ) and/or lithium manganese phosphate (LixMnPO ₄ ). It may be an olivine type compound.

The anode safety function layer 213 may be a layer that reduces the risk of fire or other unsafe situations due to short-circuit current and/or chemical reaction that occurs when the anode 210 is in contact with the cathode (e.g., the cathode 220 in FIG. 2). there is.

Referring to FIG. 3A , the anode safety function layer 213 according to various embodiments may be a first anode safety function layer 213a disposed between the anode current collector 211 and the cathode active material 212. Referring to FIG. 3B, the positive electrode safety function layer 213 according to various embodiments is a second layer located on the surface of the positive electrode active material 212 facing the surface where the positive electrode current collector 211 and the positive electrode active material 212 are in contact. It may be an anode safety function layer 213b. Referring to FIG. 3C, the positive electrode safety function layer 213 according to various embodiments includes a third positive electrode safety function layer ( 213c).

The anode safety function layer 213 (e.g., the first anode safety function layer 213a, the second anode safety function layer 213b, or the third anode safety function layer 213c) of various embodiments may include, for example, LiFePO4 and/or LiMnPO4. It may include materials such as olivine phosphates. The anode safety function layer 213 containing an olivine-based phosphate material has relatively high chemical stability when in contact with the material constituting the cathode 220, so that the anode 210 is resistant to damage such as penetration from the outside of the battery. ) and the cathode 220 can prevent chemical reactions and heat generation due to contact.

In various embodiments, anode safety functional layer 213 may include PTC material. The PTC material may be a material that has a positive thermal coefficient (PTC) in electrical resistivity. In various embodiments, the anode safety layer 213 may include PTC ceramic or PTC polymer composite material. PTC ceramics may include, for example, perovskite-based ceramics such as rare-earth doped BaTiO3. The PTC polymer composite includes, for example, a polymer matrix and conductive particles such as carbon black dispersed within the polymer matrix, and may be a material in which electrical conductivity decreases or increases due to expansion or contraction of the polymer matrix depending on temperature. The polymer matrix may include materials such as, for example, high-density polyethylene (HDPE), poly (methyl methacrylate) (PMMA), ethylene vinyl acetate (EVA), and/or polyvinylidene fluoride (PVDF).

Since the anode safety function layer 213 includes a PTC material, when the anode 210 and the cathode 220 are in direct contact and a short-circuit current flows due to damage such as penetration or pressure from the outside, the internal temperature of the battery increases. As a result, the resistivity of the PTC material may increase due to the positive temperature coefficient of the PTC material. As the electrical resistance of the anode safety function layer 213 increases, the short-circuit current is reduced, so the risk of damage to the battery and a chain reaction in which the short-circuit current increases due to heat generation by the short-circuit current can be reduced.

4A and 4B are cross-sectional views of batteries 200a and 200b according to various embodiments.

FIG. 4C is a diagram showing a state in which the wound components of the winding type battery 200b of FIG. 4B are unwound.

FIG. 4D is a diagram showing a state in which the wound components of a winding-type battery 200b according to another embodiment are unwound.

FIG. 4A is a schematic diagram showing a cross section of a stacked battery 200a, for example, the battery 100a of FIG. 1A. FIGS. 4B to 4D are diagrams illustrating a cross-section of a winding-type battery 200b, such as the batteries 100b and 100c of FIGS. 1B to 1C, and their components in an unwound state.

The cross section in FIG. 4A is a cross section in the A-A' direction of FIG. 1A, FIG. 4B is a cross section in the B-B' direction in FIG. 1B, and FIGS. 4C and 4D are a cross section in the B-B' direction in FIG. 1B. It is unfolded.

Referring to FIG. 4A, the anode safety function layer 213 may be disposed in at least a portion of the internal anode region 210b of the battery. Referring to FIG. 4A, the anode safety function layer 213 of the stacked battery may be disposed on at least a portion of the inner anode region 210b disposed between the outermost anode region 210a among the plurality of stacked anodes 210. You can. For example, the anode safety function layer 213 may be disposed in an area relatively closer to the outermost anode region 210a among the inner anode region 210b. In various embodiments, the thickness of the anode safety function layer 213 may gradually decrease from the outermost anode region 210a toward the inside (IN direction in FIG. 4A). In Figure 4a, an embodiment in which the anode safety function layer 213 is not disposed in the innermost region 210c of the internal anode region 210b is shown. However, this is an example that does not limit the present invention, and is disclosed in this document. It will be apparent that the technical idea can be applied to an embodiment in which the anode safety function layer 213 is disposed to the innermost region of the internal anode region 210b and has the thinnest thickness.

4B to 4D, the anode safety function layer 213 of the winding-type battery 200b is wound in a space located in the inner direction from the outermost anode region 210a. It may extend at least part of the internal anode region 210b. For example, the anode safety function layer 213 may be disposed in an area relatively closer to the outermost anode region 210a among the inner anode region 210b. In various embodiments, the thickness of the anode safety function layer 213 may gradually decrease from the outermost anode region 210a toward the inside (IN direction in FIG. 4C). Referring to Figure 4C, in various embodiments, the thickness of the anode safety function layer 213 may be decreased in steps. Referring to Figure 4D, in various embodiments, the thickness of the anode safety function layer 213 may continuously decrease.

4A to 4D show an embodiment in which the anode safety function layer 213 is not disposed in the innermost region of the internal anode region 210b. However, this is an example that does not limit the present invention, and is disclosed in this document. It will be apparent that the technical idea can be applied to an embodiment in which the anode safety function layer 213 is disposed to the innermost region of the internal anode region 210b and has the thinnest thickness.

By disposing the anode safety function layer 213 to at least a portion of the internal anode region 210b of the battery, the safety of the battery can be improved. In addition, since the anode safety function layer 213 disposed in the internal anode area 210b has a relatively thin thickness, battery damage that may occur due to the anode safety function layer 213 being disposed up to the internal anode area 210b Reduction in energy density and/or power density can be minimized. The thickness of the anode safety function layer 213 of the inner anode region 210b may be adjusted to optimize battery safety and energy density and/or power density of the battery.

Figure 5 is a cross-sectional view showing a battery according to various embodiments.

Referring to FIG. 5 , a battery (eg, battery 100 or battery 200) according to various embodiments may include a short-circuit protection layer 240. The short-circuit protection layer 240 is disposed to correspond to the outer peripheral surface of the outermost anode region 210a, but may be spaced apart from the outermost anode region 210a and electrically connected to the cathode 220. For example, the short-circuit protection layer 240 may be separated from the outermost anode region 210a by the insulating layer 241. The short circuit protection layer 240 may include a conductive material, for example, a metal material. The short-circuit protection layer 240 may include the same or similar material as the current collector of the electrode opposite to the electrode facing the short-circuit protection layer 240. For example, the short-circuit protection layer 240 facing the positive electrode 210 may include the same or similar material as the current collector of the negative electrode 220 (eg, copper (Cu)). In various embodiments, the negative electrode 220 current collector and the short circuit protection layer 240 each include tabs that are portions for drawing current to the outside, and the tabs are connected to each other by welding to form the negative electrode 220 and the short circuit protection layer ( 240) can be electrically connected.

When an electronic device receives damage such as penetration or pressure from the outside, the risk of fire may increase if a short-circuit current flows in the areas of the anode 210 and cathode 220 where the anode/cathode active materials are disposed. According to one embodiment, the battery includes the short circuit protection layer 240, so that when external damage occurs, the short circuit first occurs in the short circuit protection layer 240 rather than in the area where the anode/cathode active materials are disposed, and thus the anode/cathode active material is disposed. /The short-circuit current can be limited by reducing the potential difference in the area where the cathode active material is placed, thus reducing the risk of fire and other unsafe situations.

In various embodiments, the width W1 of the short-circuit protection layer 240 may be narrower than the width W2 of the outermost anode region 210a. When the width W1 of the short-circuit protection layer 240 is wider than the outermost anode area 210a, when an external impact such as dropping a battery is applied, the short-circuit protection layer 240 is deformed and the outermost anode area Since there is a risk of a short circuit occurring due to contact with 210a, this risk can be reduced by making the width W1 of the short circuit protection layer 240 narrower than the width W2 of the outermost anode region 210a.

The battery 200 according to various embodiments of the present invention includes a battery case 180 that separates the inside and outside of the battery 200, at least one anode 210 located inside the battery case 180, and a battery. It includes an electrode assembly including at least one cathode 220 positioned to face the anode 210 inside the case 180 and at least one separator 230 disposed between the anode 210 and the cathode 220. can do.

The anode 210 may include an anode safety function layer 213 disposed in an area including the outermost anode area 210a, which is the area closest to the inside of the battery case 180 among the anode 210.

In various embodiments, the battery 200 is a winding-type battery 200b in which the electrode assemblies are wound to overlap each other, and the anode 210, the cathode 220, and the separator 230 have an outermost anode region 210a. It may be wound to be positioned on the outside of the battery 200.

In various embodiments, the anode safety function layer 213 is at least one of the inner anode region 210b, which is a region wrapped in a space located in the inner direction of the battery 200 from the outermost anode region 210a of the anode 210. The anode safety function layer 213 is partially extended, and the anode safety function layer 213 is an anode safety function in which the thickness of the anode safety function layer 213 disposed in the outermost anode region 210a of the anode 210 extends to the inner anode region 210b. It may be thicker than the thickness of layer 213.

In various embodiments, the thickness of the anode safety function layer 213 may be gradually reduced toward the interior of the battery 200.

In various embodiments, the thickness of the anode safety function layer 213 may continuously decrease toward the interior of the battery 200.

In various embodiments, the battery 200 is a stacked battery 200a including a plurality of anodes 210, a plurality of cathodes 220, and a plurality of separators 230 that are alternately stacked, and the outermost anode region ( 210a) may be the anodes 210 located on the uppermost and lowermost layers among the plurality of anodes 210 stacked.

In various embodiments, the anode safety function layer 213 is further disposed on at least a portion of the inner anode region 210b, which is the anodes 210 stacked between the outermost anode regions 210a, and the anode safety function layer 213 ), the thickness of the anode safety function layer 213 disposed in the outermost anode region 210a of the anode 210 may be thicker than the thickness of the anode safety function layer 213 disposed in the inner anode region 210b. .

In various embodiments, the thickness of the anode safety function layer 213 may gradually decrease toward the interior of the battery 200.

In various embodiments, the positive electrode 210 includes a positive electrode current collector 211 and a positive electrode active material 212 located on the surface of the positive electrode current collector 211,

The positive electrode safety function layer 213 may be located between the positive electrode current collector 211 and the positive electrode active material 212.

In various embodiments, the positive electrode 210 includes a positive electrode current collector 211 and a positive electrode active material 212 located on a surface of the positive electrode current collector 211, and the positive electrode safety function layer 213 includes a positive electrode active material 212. ) can be coated on the surface.

In various embodiments, the anode safety functional layer 213 may include a positive temperature coefficient (PTC) material.

In various embodiments, the PTC material may include a polymer composite.

In various embodiments, the anode safety function layer 213 may include a phosphate-based olivine material.

In various embodiments, the battery 200 casing is spaced apart from the outermost anode region 210a and is disposed to surround at least a portion of the outer peripheral surface of the outermost anode region 210a, and is electrically connected to the cathode 220. and may include a short-circuit protection layer 240 made of a conductive material.

In various embodiments, the width of the short-circuit protection layer 240 may be narrower than the width of the outermost anode region 210a.

In various embodiments, the anode 210 may further include a cathode safety function layer 223 formed in an area of the cathode 220 corresponding to the area where the anode safety function layer 213 is disposed. ).

The battery 200 according to various embodiments of the present invention includes a battery 200 casing that separates the inside and outside of the battery 200, at least one anode 210 located inside the battery 200 casing, and a battery ( 200) At least one cathode 220 positioned to face the anode 210 inside the casing, at least one separator 230 disposed between the anode 210 and the cathode 220, and the anode 210 or the cathode. It may include a safety function layer (213, 223) disposed on at least one of (220). The thickness of the safety function layers 213 and 223 may increase as they are located relatively closer to the outside of the battery 200.

In various embodiments, the safety functional layers 213 and 223 are disposed on the anode 210 and may include a positive temperature coefficient (PTC) material.

In various embodiments, the PTC material may include a polymer composite.

In various embodiments, the safety functional layers 213 and 223 are disposed on the anode 210 and may include a phosphate-based olivine material.

In addition, the embodiments disclosed in this document and the drawings are merely presented as specific examples to easily explain the technical content according to the embodiments disclosed in this document and to aid understanding of the embodiments disclosed in this document. It is not intended to limit the scope of the examples. Therefore, the scope of the various embodiments disclosed in this document includes all changes or modified forms derived based on the technical idea of the various embodiments disclosed in this document in addition to the embodiments disclosed herein. must be interpreted.

200: battery
210: anode
210a: outermost anode region
210b: internal anode area
213: anode safety function layer
220: cathode
223: cathode safety function layer
230: Separator
240: short circuit protection layer

Claims (20)

In batteries,
a battery case that separates the inside and outside of the battery; and
An electrode assembly including at least one anode positioned inside the battery case, at least one cathode positioned inside the battery case to face the anode, and at least one separator disposed between the anode and the cathode; ,
The anode is a battery including an anode safety functional layer disposed in an area including an outermost anode area, which is the area closest to the inside of the battery case among the anodes. According to claim 1,
The battery is a winding type battery in which the electrode assemblies are wound so as to overlap each other,
A battery in which the anode, the cathode, and the separator are wound so that the outermost anode region is located toward the outside of the battery. According to claim 2,
The anode safety functional layer extends from the outermost anode region among the anodes to at least a portion of an inner anode region, which is an area wrapped in a space located in the inner direction of the battery,
The anode safety functional layer is,
A battery in which the thickness of the anode safety functional layer disposed in the outermost anode region among the anodes is thicker than the thickness of the anode safety functional layer extended to the inner anode region. According to claim 3,
A battery in which the thickness of the anode safety function layer gradually decreases toward the inside of the battery. According to claim 3,
A battery in which the thickness of the anode safety function layer continuously decreases toward the inside of the battery. According to claim 1,
The battery is a stacked battery including a plurality of anodes, a plurality of cathodes, and a plurality of separators that are alternately stacked,
The outermost anode region is a battery wherein the anodes are located on the uppermost and lowermost layers among the plurality of stacked anodes. According to claim 6,
the anode safety functional layer is further disposed on at least a portion of an inner anode region where the anodes are stacked between the outermost anode regions,
The anode safety function layer is,
A battery in which the thickness of the anode safety function layer disposed in the outermost anode region among the anodes is thicker than the thickness of the anode safety function layer disposed in the inner anode region. According to claim 7,
A battery in which the thickness of the anode safety function layer gradually decreases toward the inside of the battery. According to claim 1,
The positive electrode includes a positive electrode current collector and a positive electrode active material located on a surface of the positive electrode current collector,
The battery wherein the positive electrode safety function layer is located between the positive electrode current collector and the positive electrode active material. According to claim 1,
The positive electrode includes the positive electrode current collector and a positive electrode active material located on a surface of the positive electrode current collector,
A battery in which the positive electrode safety function layer coats the surface of the positive electrode active material. According to claim 1,
A battery wherein the anode safety function layer includes a positive temperature coefficient (PTC) material. According to claim 11,
The PTC material is a battery comprising a polymer composite. According to claim 1,
A battery wherein the anode safety function layer includes a phosphate-based olivine material. According to claim 1,
A battery comprising a short-circuit protection layer disposed inside the battery casing, spaced apart from the outermost anode region and surrounding at least a portion of an outer peripheral surface of the outermost anode region, electrically connected to the cathode, and having a conductive material. According to claim 14,
A battery in which the width of the short-circuit protection layer is narrower than the width of the outermost anode region. According to claim 1,
The battery of the battery further comprising a cathode safety function layer formed in an area of the cathode corresponding to an area of the anode where the anode safety function layer is disposed. In batteries,
a battery casing that separates the inside and outside of the battery;
At least one anode located inside the battery casing;
at least one cathode positioned to face the anode inside the battery casing;
at least one separator disposed between the anode and the cathode; and
a safety function layer disposed on at least one of the anode or the cathode,
The safety function layer is a battery whose thickness increases as it is located relatively close to the outside of the battery. According to claim 17,
The safety function layer is disposed on the anode and includes a positive temperature coefficient (PTC) material. According to claim 18,
The PTC material is a battery comprising a polymer composite. According to claim 17,
The safety function layer is disposed on the anode, and the battery includes a phosphate-based olivine material.

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