KR20230063458A - Positive electrode for secondary battery with improved safety and battery cell including same - Google Patents

Abstract

The present invention relates to a positive electrode for a secondary battery with improved safety, which can improve safety by reducing heat generation even when an internal or external short circuit occurs, and a battery cell including the same. The positive electrode for a secondary battery includes: a metal current collector; and a mixture layer formed on one or both sides of the metal current collector. The mixture layer includes first and second regions positioned on the same plane. The first region includes lithium iron phosphate as a positive electrode material, and the second region includes nickel cobalt manganese as a positive electrode material.

Description

Positive electrode for secondary battery with improved safety and battery cell including same}

The present invention relates to a battery cell with improved safety, a lithium secondary battery including the same, and a battery module and battery pack including the lithium secondary battery.

As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. and is widely used.

A lithium secondary battery is generally manufactured by interposing two electrodes having different potentials and a separator for preventing an electrical short between the two electrodes, and then injecting an electrolyte that delivers lithium ions into the two electrodes. As the electrolyte, an organic electrolyte solution in which lithium salt is dissolved in an organic solvent is mostly used.

In such a lithium secondary battery, when an internal short circuit caused by a foreign substance or an external short circuit caused by penetration of a material such as a nail occurs, a large current flows and heat generation or explosion may occur, and safety improvement is evaluated as important.

Therefore, it is necessary to develop a technology for securing the safety of the secondary battery.

Republic of Korea Patent Publication No. 10-2016-0091732

The present invention is to solve the above problems, and even if an internal short circuit or an external short circuit occurs, a battery cell with improved safety capable of improving safety by reducing heat generation, a lithium secondary battery including the same, and a lithium secondary battery including the An object of the present invention is to provide a battery module and a battery pack.

In order to solve the above problems, a positive electrode for a secondary battery with improved safety is provided.

In one example, a cathode for a secondary battery according to the present invention includes a metal current collector; A mixture layer formed on one or both surfaces of a metal current collector, wherein the mixture layer includes first and second regions positioned on the same plane, and the first region contains lithium iron phosphate as a cathode material; , The second region may include nickel cobalt manganese as an anode material, and may have a structure in which an insulating layer is formed on the first region.

In a specific example, the positive electrode for a secondary battery according to the present invention may satisfy Condition 1 below.

[Condition 1]

R1 > R2

In condition 1, R1 and R2 represent the electrical resistances of the first and second regions, respectively.

In one example, the second region may further include lithium iron phosphate as a cathode material.

In another example, the positive electrode for a secondary battery according to the present invention has a structure of an upper layer and a lower layer including first and second regions, and lithium cobalt manganese may be included in the lower layer.

In addition, in one embodiment, the first area may be a structure formed in an area of 1-20% based on the total area of the mixture layer.

In one example, the present invention includes the anode described above; cathode; and a separator disposed between the positive electrode and the negative electrode, wherein the separator is disposed in an area other than the first region of the positive electrode.

Specifically, the battery cell according to the present invention may be characterized in that the melting point of the insulating layer is 10 to 20 ° C lower than the melting point of the separator.

In one example, in the battery cell according to the present invention, the insulating layer and the separator may have the same thickness.

In addition, in the positive and negative electrodes of the battery cell according to the present invention, electrode tabs extending from the current collector are formed, and each electrode tab is disposed to face in opposite directions, and the first region of the positive electrode is the positive electrode tab. It may have a structure formed along one or more sides of two sides adjacent to the opposite region or the region where the positive electrode tab is formed.

In addition, the battery cell according to the present invention may be a stack type or a stack/fold type.

In the cathode for a secondary battery according to the present invention, when an internal short circuit or an external short circuit occurs, the insulating layer melts, and the first region of the anode and the negative electrode contact each other, causing a short circuit. At this time, the safety of the lithium secondary battery can be improved by reducing the amount of heat generated and the explosive power by acting as a resistance part in the first region having high resistance.

1 is a cross-sectional view of a cathode for a secondary battery according to the present invention.
2 is a cross-sectional view of a battery cell according to the present invention.
3 is an exploded perspective view of a battery cell according to the present invention.
4 is another cross-sectional view of a cathode for a secondary battery according to the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments will be described in detail.

However, this is not intended to limit the present invention to the specific embodiments, and should be understood to include all modifications, equivalents, or substitutes included in the technical spirit and scope of the present invention.

In the present invention, the term "comprises" or "has" is intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Further, in the present invention, when a part such as a layer, film, region, plate, etc. is described as being “on” another part, this includes not only the case where it is “directly on” the other part, but also the case where another part is present in the middle. Conversely, when a part such as a layer, film, region, plate, or the like is described as being “under” another part, this includes not only being “directly under” the other part, but also the case where there is another part in the middle. In addition, in the present application, being disposed "on" may include the case of being disposed not only on the upper part but also on the lower part.

The present invention provides a positive electrode for a secondary battery with improved safety, a battery cell including the same, a lithium secondary battery including the battery cell, a battery module including the lithium secondary battery, and a battery pack.

In one example, a cathode for a secondary battery according to the present invention includes a metal current collector; A mixture layer formed on one or both surfaces of a metal current collector, wherein the mixture layer includes first and second regions positioned on the same plane, and the first region contains lithium iron phosphate as a cathode material; , The second region may include nickel cobalt manganese as an anode material, and may have a structure in which an insulating layer is formed on the first region.

In a specific example, the positive electrode for a secondary battery according to the present invention may satisfy Condition 1 below.

[Condition 1]

R1 > R2

In condition 1, R1 and R2 represent the electrical resistances of the first and second regions, respectively.

In one example, the second region may further include lithium iron phosphate as a cathode material.

In particular, in the positive electrode for a secondary battery according to the present invention, when the internal temperature of the battery rises abnormally, the insulating layer melts and the first region of the electrode comes into contact with the mixture layer of the opposite electrode, resulting in a short circuit. At this time, a first region, which is a high resistance region in which current is not concentrated, comes into contact with one surface of the opposite electrode, and a relatively low energy short circuit may occur. This has an advantage in that the safety of the battery can be improved by reducing the amount of heat generated and explosive power by the first region having high resistance acting as a resistance part.

Hereinafter, a positive electrode for a secondary battery with improved safety including an insulating layer according to the present invention, a battery cell including the same, a lithium secondary battery including the battery cell, a battery module and a battery pack including the lithium secondary battery are described in detail with reference to the drawings. Explain.

Anodes and battery cells for secondary batteries

[First Embodiment]

A first embodiment of a positive electrode for a secondary battery with improved safety according to the present invention is provided. Specifically, the cathode mixture layer for a secondary battery according to the first embodiment may include first and second regions that satisfy Condition 1.

1 is a cross-sectional view of a positive electrode for a secondary battery according to the present invention, FIG. 2 is an exploded perspective view of a battery cell according to the present invention, and FIG. 3 is a cross-sectional view of the battery cell according to the present invention.

1 to 3, the positive electrode 10 according to the present invention may include first and second regions 121 and 122 located on the same plane of the positive electrode mixture layer 12, under the following conditions. 1 can be satisfied.

[Condition 1]

R1 > R2

In condition 1, R1 and R2 represent the electrical resistances of the first and second regions, respectively.

In a specific example, the first region 121 and the second region 122 exhibit different resistance characteristics, and the first region 121 is designed to exhibit higher resistance than the second region 122 .

The battery cell according to the present invention may include a positive electrode 10, a negative electrode 20, and a separator 30 positioned between the positive electrode 10 and the negative electrode 20. Specifically, the positive electrode 10 and the negative electrode 20 each include current collectors 11 and 21 and mixture layers 12 and 22 formed on one or both surfaces of the current collector, and the current collectors 11 and 21 It may have a structure in which electrode tabs 13 and 23 extending from the electrode tabs are formed. Meanwhile, in the drawings, the positive electrode 10 and the negative electrode 20 are illustrated such that the mixture layers 12 and 22 are formed on both sides of the current collectors 11 and 21, but are not limited thereto.

In one example, since the first region 121 of the positive electrode mixture layer 12 is insulated by the insulating layer 14 , it may not participate in a normal charge/discharge reaction of the battery. However, in the first region 121 and the second region 122, the internal temperature of the battery abnormally rises, resulting in damage to the battery such as a short circuit of the battery, so that current is concentrated in a local region with low resistance, and as a result, the current rapidly increases. Heat may be generated. Here, the abnormal increase in the internal temperature of the battery does not mean a temperature increase of the battery cell including the electrode on which the first and second regions are formed, but an abnormal temperature increase around the battery cell to which the electrode is applied. will be.

At this time, in the present invention, the positive electrode mixture layer 12 is designed so that the low resistance region and the high resistance region are distributed, so that when the internal temperature of the battery rises abnormally, the first region, which is a high resistance region where current is not concentrated ( 121) is in contact with one surface of the negative electrode 20 to generate a relatively low short circuit.

That is, an object of the present invention is to reduce the explosive force by lowering the energy of the secondary battery before thermal runaway by generating a short circuit with relatively low intensity in the first region when the internal temperature of the battery rises abnormally.

As described above, according to the present invention, when the internal temperature of the battery rises abnormally, the first region 121 comes into contact with the mixture layer 22 of the negative electrode 20 and a short circuit occurs, but the current passes through the second region 122. Movement is induced, so that a relatively low shot occurs in the first region 121, reducing the explosive force.

Meanwhile, an insulating layer 14 is formed on one surface of the anode 10, and the separator 30 disposed between the anode 10 and the cathode 20 is disposed in an area other than the first area 121. can In particular, when the internal temperature of the battery rises abnormally, the insulating layer 14 melts, and the first region 121 of the positive electrode 10 comes into contact with the mixture layer 22 of the negative electrode 20, resulting in a short circuit. can make it

As described above, the first and second regions 121 and 122 have different resistances, but the resistance of the first region 121 is higher. In this case, the cathode material of the first region includes lithium iron phosphate (LiFePO ₄ , LFP) and the cathode material of the second region includes nickel cobalt manganese (NMC), and resistance values of each region may be set differently. In this case, when the resistance value of the first region 121 is too great than the resistance value of the second region 122, a short circuit may be difficult to occur even when the internal temperature of the battery rises abnormally due to a small current movement. In addition, when the difference between the resistance value of the first region 121 and the resistance value of the second region 122 is too small, ignition due to a short circuit may occur.

Specifically, a slurry for a mixture layer containing lithium iron phosphate (LiFePO ₄ , LFP) may be applied to the first region. In this case, lithium iron phosphate may be included in an amount of 80 to 99 parts by weight based on the slurry for the positive electrode mixture layer applied to the first region. More specifically, it may be 85 to 98 parts by weight, 88 to 97 parts by weight, 90 to 96 parts by weight or 95 parts by weight.

Specifically, a slurry for a mixture layer of a cathode material including nickel, cobalt, manganese (Nickel, Manganese, Cobalt, NMC) may be applied to the second region. In this case, the positive electrode material containing nickel cobalt manganese may be included in an amount of 80 to 99 parts by weight based on the slurry for the positive electrode mixture layer applied to the second region. More specifically, it may be 85 to 98 parts by weight, 88 to 97 parts by weight, 90 to 96 parts by weight or 95 parts by weight. In addition, nickel, cobalt, and manganese may have various composition ratios. For example, nickel, manganese, and cobalt may have a molar ratio of 0.4 to 0.95 nickel, 0.025 to 0.3 manganese, and 0.025 to 0.3 cobalt, respectively. More specifically, it may have a composition ratio of Ni _0.6 Co _0.2 Mn _0.2 , Ni _0.7 Co _0.15 Mn _0.15 , Ni _0.8 Co _0.1 Mn _0.1 , and Ni _0.9 Co _0.05 Mn _0.05 .

In the positive electrode for a secondary battery according to the present invention, the first region 121 may be included in an area of 1% or more based on the total area of the positive electrode mixture layer 12 . In a specific example, the first region 121 is 1% or more, 5% or more, 1 to 20%, 3 to 18%, 5 to 16%, 7 to 14% based on the total area of the positive electrode mixture layer 12 %, 9 to 12%, 10% or in the region. If the area of the first region 121 is too large, the region that does not participate in a normal charge/discharge reaction becomes too large and energy loss may occur. On the other hand, if the area of the first region 121 is too small, a short circuit may occur in the first region 121 in contact with the mixture layer 22 of the negative electrode 20 when the temperature of the battery rises abnormally. Since the area of the first region 121 is too narrow, it may be difficult to sufficiently lower the energy until the thermal runaway temperature is reached.

In addition, the insulating layer 14 disposed on one or both surfaces of the first region 121 may be a polymer resin layer, and the melting temperature of the insulating layer 14 is preferably lower than that of the separator. For example, the melting point of the insulating layer may be 10 to 20 °C, 5 to 15 °C, or 10 °C lower than the melting point of the separator. More specifically, the melting temperature of the insulating layer 14 may be 150 °C or less on average. Specifically, the melting temperature of the insulating layer 14 may be 40 to 150 °C, 50 to 120 °C, 60 to 100 °C, 120 °C or less, or 100 °C or less. However, the melting temperature is not limited to this temperature range, and the melting temperature may be changed depending on the type of polymer resin layer to be the insulating layer 14 .

If the melting temperature of the insulating layer 14 is too low, the polymer resin melts in the temperature range in which the battery normally operates, and the positive electrode 10 and the negative electrode 20 may come into contact with each other, resulting in a short circuit. If the melting temperature of (14) is too high, the insulating layer 14 is not melted even when the internal temperature of the battery rises abnormally, and problems such as heat transfer or fire may occur.

In addition, the separator 30 is not disposed in the region where the insulating layer 14 is located, and the insulating layer 14 can prevent a hard short or the like that instantaneously occurs during normal operation of the battery. In a specific example, the insulating layer 14 may be a polymer material such as PVdF-co-HFP, polyethylene, or polypropylene, or may be a polymer wax.

Meanwhile, the separator 30 may be positioned between the anode 10 and the cathode 20 and may be disposed in an area other than the first area 121 of the cathode mixture layer 12 . The separator 30 may be an insulating thin film having high ion permeability and mechanical strength. Separator 30 is not particularly limited as long as it is commonly used in the art, but specifically, chemical resistant and hydrophobic polypropylene; glass fiber; Alternatively, a sheet or non-woven fabric made of polyethylene or the like may be used. In some cases, a composite separator 30 in which inorganic particles/organic particles are coated with an organic binder polymer on a porous polymer substrate such as the sheet or non-woven fabric may be used. there is. When a solid electrolyte such as a polymer is used as the electrolyte, the solid electrolyte may serve as a separation membrane. In addition, the separator may have an average pore diameter of 0.01 to 10 μm and an average thickness of 5 to 300 μm. For example, the separator 30 may be a composite separator coated with an organic binder polymer such as polyvinylidene fluoride (PVdF) or styrene butadiene rubber (SBR). Also, the separator 30 may have the same thickness as the insulating layer 14 . If the thickness is the same, the bonding between the separator 39 and the insulating layer 14 can be firmly maintained, and the bonding between the separator and the insulating layer and the positive electrode and/or the negative electrode can also be firmly maintained.

In the present invention, the positive electrode 10 and the negative electrode 20 have a structure in which electrode tabs 13 and 23 extending from the current collectors 11 and 21 are formed, and the respective electrode tabs 13 and 23 are directed in opposite directions to each other. can be placed facing up.

Referring to FIG. 3 , the first region 121 may represent a structure formed in a region opposite to the positive electrode tab 13 . The structures of the first and second regions are not limited thereto. In addition to this, the first and second regions 121 and 122 may be arranged in various forms. However, the first region 121 is not disposed in the region where the positive electrode tab 13 is formed. Specifically, the separator 30 is disposed in an area other than the first region 121. When the first region 121 is disposed in the mixture layer 12 in the region where the positive electrode tab 13 is formed, the positive electrode tab (13) comes into contact with the mixture layer 22 of the negative electrode 20, making normal charging and discharging impossible, and a high-intensity short circuit may occur.

The battery cell according to the present invention can be stacked in various forms, for example, stacked, stacked/folded, etc., and preferably has a stacked structure. The electrode tabs extend from each electrode plate of the battery cell, and the electrode lead is electrically connected to a plurality of electrode tabs extending from each electrode plate by, for example, welding, and exposed to the outside of the pouch.

In the present invention, the electrode may be stacked together with a conventional electrode having an electrode active material layer formed on both sides of a current collector to form a unit cell such as a bi-cell or a mono-cell. In a specific example, the battery cell in the secondary battery according to the present invention may include at least one selected from the group consisting of a mono-cell and a bi-cell. More specifically, in the mono cell, electrodes having opposite polarities are disposed on both sides of the unit cell. In addition, the bi-cell is a unit cell that has the same polarity on both sides of the cell, such as a unit structure of an anode/separator/cathode/separator/anode and a unit structure of cathode/separator/anode/separator/cathode. These monocells and bicells are not particularly limited in the number of separators of the positive and negative electrodes constituting them as long as the electrodes on both sides of the unit cell have the same structure.

[Second Embodiment]

The present invention provides a battery cell with improved safety in a second embodiment. Specifically, in the battery cell of the second embodiment, the positions of the first region 121 and the second region 122 of the positive electrode mixture layer 12 may be formed differently from those of the first embodiment.

4 is another cross-sectional view of a cathode for a secondary battery according to the present invention. Referring to FIG. 4 , the first region 121 may represent a structure formed along at least one of two sides adjacent to the region where the positive electrode tab 13 of the positive electrode 10 is formed.

A positive electrode for a secondary battery may be formed in the same manner as in the first embodiment described above except for the formation position of the positive electrode for a secondary battery, and a battery cell including the positive electrode may be formed.

lithium secondary battery

The present invention provides a lithium secondary battery including the positive electrode for a secondary battery described above and a battery cell including the same. Specifically, the lithium secondary battery according to the present invention includes the battery cell described above and a pouch case accommodating the battery cell.

The pouch is usually made of an aluminum laminate sheet and may provide a space capable of accommodating a battery cell. Meanwhile, the electrode leads may be drawn out of the pouch and may extend in the same direction or opposite directions.

The lithium secondary battery according to the present invention may include the battery cell described above. In particular, when the ambient temperature of the battery cell abnormally rises, the polymer resin layer melts, and the first region of the positive electrode and the negative electrode contact each other, causing a short circuit. At this time, the first region with high resistance acts as a resistance part to reduce the amount of heat generated and explosive power, thereby improving the safety of the lithium secondary battery.

Battery Modules and Battery Packs

The present invention provides a battery module including the secondary battery described above. In addition, the present invention provides a battery pack including the battery module.

In one example, the lithium secondary battery according to the present invention can be used for a high-power, large-capacity battery requiring long lifespan and excellent durability, or a battery module including a plurality of such batteries as unit cells, or a battery pack. .

In a specific example, when an event, such as a temperature rise, occurs in one of the plurality of lithium secondary batteries of the battery module or battery pack, the battery cells included in the above-described lithium secondary battery due to an increase in ambient temperature When the insulating layer melts, the first region of the anode and the cathode contact each other, causing a short circuit. In this case, by generating a low-intensity short circuit in the first region, the energy of the lithium secondary battery is lowered before thermal runaway, thereby reducing explosive force.

The battery pack can be used as a power source for medium or large sized devices requiring high temperature stability, long cycle characteristics, high rate characteristics, etc. Specific examples of such medium or large sized devices include a power tool powered by an omniscient motor and moving; electric vehicles, including electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs); electric two-wheeled vehicles including electric bicycles (E-bikes) and electric scooters (E-scooters); Electric golf cart; electric truck; electric commercial vehicles or systems for power storage.

Since the structure and manufacturing method of such a medium or large battery module or medium or large battery pack is well known in the art, a detailed description thereof will be omitted.

Hereinafter, the present invention will be described in more detail by examples and experimental examples.

However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the contents of the present invention are not limited to the following Examples and Experimental Examples.

Example 1

95 parts by weight of lithium iron phosphate (LiFePO ₄ ) as the first cathode active material, 3.5 parts by weight of carbon black as a conductive material, and 1.5 parts by weight of PVdF as a binder were weighed and mixed in an N-methylpyrrolidone (NMP) solvent to form a first A slurry for a positive electrode mixture layer was prepared.

Then, the slurry for the first positive electrode mixture layer was applied to the first region of the current collector having a thickness of 12 μm.

95 parts by weight of LiNi _0.8 Co _0.1 Mn _0.1 O ₂ as the second cathode active material, 3.5 parts by weight of carbon black as a conductive material, and 1.5 parts by weight of PVdF as a binder were weighed and mixed in N-methylpyrrolidone (NMP) solvent to prepare 2 A slurry for the positive electrode mixture layer was prepared.

Then, the slurry for the positive electrode mixture layer was applied to the second region of the positive electrode current collector having a thickness of 12 μm.

In this case, the first region was formed in an area of 5% of the total area of the positive electrode mixture layer, and the second region was formed in the remaining area.

Thereafter, the positive electrode was prepared by drying and rolling at 130°C.

After preparing lithium metal as the anode and counter electrode and placing a polypropylene separator between them, using an electrolyte of ethylene carbonate / dimethyl carbonate / LiPF ₆ (EC / DMC = 1/1), coin half cell ) was prepared.

Comparative Example 1

96.8 parts by weight of LiNi _0.8 Co _0.1 Mn _0.1 O ₂ as a cathode active material, 1.7 parts by weight of carbon black as a conductive material, and 1.5 parts by weight of PVdF as a binder were weighed and mixed in an N-methylpyrrolidone (NMP) solvent to obtain a slurry for a mixture layer. A coin half cell was manufactured in the same manner as in Example 1, except that was prepared and applied to the current collector.

resistance measurement experiment

After fixing the battery cells prepared in Example and Comparative Example to a cell jig equipped with a heating pad, abnormal heat was applied to each battery cell using the heating pad to induce thermal runaway of the battery cell. And, the results are shown in Table 1 below.

division Cell data Experiment result bipolar MP resistor
(mΩ/cm ² ) DCIR
(mΩ) TRstart temperature
(℃) total burning time
(candle) Example 1 125~153 1.21 267 169 Comparative Example 2 20 to 30 1.09 233 157

Referring to Table 1, the total thermal runaway (TR) temperature of Example 1 was about 34 degrees high. Through this, it was confirmed that the thermal stability of Example 1 was increased. In addition, the total burning time of the battery cell in Example 1 was increased by about 12 seconds compared to Comparative Example 1. This is because Example 1 and Comparative Example 1 are battery cells having the same capacity and emitting the same energy, and the increase in the burning time can be seen as the weakening of the flame intensity.

As can be seen from the table above, the present invention has an effect of improving safety by reducing heat generation even when an internal short circuit or an external short circuit occurs in the battery.

In the above, the present invention has been described in more detail through drawings and examples. however

B. Since the configurations described in the drawings or embodiments described in this specification are only one embodiment of the present invention and do not represent all of the technical spirit of the present invention, various equivalents and It should be understood that variations may exist.

10: anode
11: positive current collector
12: positive electrode mixture layer
121 first area
122: second area
13: anode tab
14: insulating layer
20: cathode
21: negative electrode current collector
22: negative electrode mixture layer
23: cathode tab
30: separator

Claims (10)

metal current collector;
It includes a mixture layer formed on one side or both sides of the metal current collector,
The mixture layer includes first and second regions located on the same plane,
The first region includes lithium iron phosphate as a cathode material,
The second region includes nickel cobalt manganese as a cathode material,
A cathode for a secondary battery having a structure in which an insulating layer is formed on the first region.
According to claim 1,
A positive electrode for a secondary battery that satisfies the following condition 1:
[Condition 1]
R1 > R2
In condition 1, R1 and R2 represent the electrical resistances of the first and second regions, respectively.
According to claim 1,
A cathode for a secondary battery, further comprising lithium iron phosphate as a cathode material in the second region.
According to claim 1,
The composite layer is
an upper layer including the first and second regions; and
It is a layered structure,
The lower layer is a cathode for a secondary battery, characterized in that it contains lithium cobalt manganese.
According to claim 1,
The first region is a cathode for a secondary battery having a structure formed in an area of 1-20% based on the total area of the mixture layer.
an anode according to claim 1;
cathode; and
Including a separator positioned between the anode and the cathode,
The battery cell having a structure in which the separator is disposed in an area other than the first area of the anode.
According to claim 6,
The melting point of the insulating layer is a battery cell, characterized in that 10 to 20 ℃ lower than the melting point of the separator.
According to claim 6,
Battery cell, characterized in that the thickness of the insulating layer and the separator is the same
According to claim 6,
The positive electrode and the negative electrode are formed with electrode tabs extending from the current collector, and are disposed so that the respective electrode tabs face opposite directions,
The battery cell of claim 1 , wherein the first region of the positive electrode is formed along at least one side of two sides adjacent to an area on the opposite side of an electrode tab or an area where the electrode tab is formed.
According to claim 6,
The battery cells are stacked or stacked/folded battery cells.

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