Battery cell

Abstract

The present application can provide an electric device including a battery cell capable of securing an excellent capacity retention rate, high current output, and appropriate capacity by combining an electrode responsible for high capacity and an electrode responsible for high current output, and capable of flexibly responding to rapidly changing current output conditions while having appropriate capacity, and an electric vehicle having excellent output and improved driving range including said battery cell.

Description

Technology Field

[0001] This application relates to a battery cell. Furthermore, this application relates to an application of a battery cell. Background Technology

[0002] The performance of a battery can be determined by the performance of the battery cell, which serves as the functional unit, and the performance of the battery cell can be determined by the electrodes (positive and negative electrodes) and electrolyte constituting the battery cell. In particular, the type and content of the active material used in the electrodes or other materials can directly affect the performance of the battery cell. The problem to be solved

[0003] The present application may provide a battery cell capable of securing an excellent capacity retention rate, high current output, and appropriate capacity by combining an electrode responsible for high capacity and an electrode responsible for high current output. Additionally, the present application may provide a battery module or battery pack comprising the battery cell.

[0004] The present application can provide a battery cell capable of flexibly responding to rapidly changing current output conditions while having an appropriate capacity. Furthermore, the present application can provide an electric vehicle with excellent output and improved driving range by including a battery cell having these characteristics. means of solving the problem

[0005] A battery cell according to one embodiment of the present application comprises a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode comprises a first positive electrode and a second positive electrode, wherein the first positive electrode comprises a first positive active material layer and the second positive electrode comprises a second positive active material layer, wherein the first positive active material layer and the second positive active material layer each comprise a positive active material, a positive binder, and a conductive material, and the first positive electrode and the second positive electrode may satisfy at least one of the following conditions.

[0006] [condition]

[0007] Condition i) the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer are different materials, or condition ii) the content ratio of at least one of the positive active material, positive binder, and conductive material included in the first positive active material layer and the second positive active material layer is different, or condition iii) the loading amount (LW1) of the first positive active material composition forming the first positive active material layer and the loading amount (LW2) of the second positive active material composition forming the second positive active material layer are different.

[0008] In a battery cell according to one embodiment of the present application, the first positive electrode includes a first positive electrode tab, and the second positive electrode includes a second positive electrode tab, and the first positive electrode tab and the second positive electrode tab may be connected to the same positive electrode lead.

[0009] In a battery cell according to one embodiment of the present application, the second positive electrode is compared to the first positive electrode in the following formula R when n is 100 CP R,n This could be higher.

[0010] [Formula R]

[0011] CP R,n = CP n / CP1×100

[0012] In formula R, CP n n represents the n-cycle discharge capacity, and CP1 represents the 1-cycle discharge capacity.

[0013] In a battery cell according to one embodiment of the present application, the ratio (N1 / N2) of the number of the first positive electrode (N1) and the number of the second positive electrode (N2) may be 10 or less.

[0014] In a battery cell according to one embodiment of the present application, the number of first positive electrodes (N1) is the total number of positive electrodes (N T It is 95% or less of ) and the number of the second anode (N2) is the total number of anodes (N T It may be 5% or more (excluding 100%) compared to ).

[0015] In a battery cell according to one embodiment of the present application, the negative electrode comprises a first negative electrode and a second negative electrode, the first negative electrode comprises a first negative electrode active material layer, and the second negative electrode comprises a second negative electrode active material layer, wherein the first negative electrode active material layer and the second negative electrode active material layer each comprise a negative electrode active material, a negative electrode binder, and a conductive material, and the first negative electrode and the second negative electrode may satisfy the following conditions.

[0016] [condition]

[0017] Condition iv) at least one constituent element or content ratio of the main compound among the cathode active material included in the first cathode active material layer and the main compound among the cathode active material included in the second cathode active material layer are different, or condition v) at least one content ratio of the cathode active material, cathode binder, and conductive material included in the first cathode active material layer and the second cathode active material layer is different, or condition vi) the loading amount (LW3) of the first cathode active material composition forming the first cathode active material layer and the loading amount (LW4) of the second cathode active material composition forming the second cathode active material layer are different.

[0018] In a battery cell according to one embodiment of the present application, the first negative electrode includes a first negative electrode tab and the second negative electrode includes a second negative electrode tab, and the first negative electrode tab and the second negative electrode tab may be connected to the same negative lead.

[0019] In a battery cell according to one embodiment of the present application, under condition i), the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer may be materials having at least one different constituent element, or materials having different compositional ratios of elements constituting the same chemical formula even if expressed by the same chemical formula.

[0020] In a battery cell according to one embodiment of the present application, under condition i), the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer may each independently include one or more compounds selected from the group consisting of a compound represented by the following chemical formula P1, a compound represented by the chemical formula P2, and a compound represented by the chemical formula P3, and the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer may have one or more elements selected from the group consisting of A, M1, M2, and M3 in the following chemical formulas P1, P2, and P3 that are different, or one or more numerical values ​​selected from the group consisting of a, x, y, and z that are different.

[0021] [Chemical Formula P1]

[0022] A a M 1x M 2y M 3z O2

[0023] [Chemical Formula P2]

[0024] A a M 1x M 2y M 3z (PO4)

[0025] [Chemical Formula P3]

[0026] A a M 1x M 2y M 3z (CN)6

[0027] In the above formulas P1, P2, and P3, A is lithium (Li), sodium (Na), or potassium (K); M1, M2, and M3 are one or more selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), chromium (Cr), vanadium (V), niobium (Nb), boron (B), aluminum (Al), copper (Cu), zirconium (Zr), tungsten (W), titanium (Ti), zinc (Zn), gallium (Ga), germanium (Ge), molybdenum (Mo), tantalum (Ta), yttrium (Y), barium (Ba), and hafnium (Hf) so as not to overlap with each other; x, y, and z are each independently 0 or greater to 1 or less, satisfying x+y+z=1; in the above formula P1, a is 0.5 or greater to 1.8 or less; and in the above formula P2, a is 0.8 or greater to 1.2 or less. In the chemical formula P3, a is 0.8 or more to 2.2 or less.

[0028] In a battery cell according to one embodiment of the present application, under condition i), the content ratio (W) of the positive active material included in the first positive active material layer PA1 ) and the ratio of the content of the positive active material included in the second positive active material layer (W PA2 ) difference (W PA1 -W PA2 The absolute value of ) may be 1 weight% or less.

[0029] In a battery cell according to one embodiment of the present application, under condition ii), the content ratio (W) of the conductive material included in the first positive active material layer PC1 ) is the content ratio of the conductive material included in the second positive active material layer (W PC2 It can be larger than )

[0030] In a battery cell according to one embodiment of the present application, under condition ii), the content ratio (W) of the conductive material included in the first positive active material layer PC1 ) and the ratio of the content of the conductive material included in the second positive active material layer (W PC2 ) difference (W PC1 -W PC2) may be 3 weight% or more.

[0031] In a battery cell according to one embodiment of the present application, under condition ii), the content ratio (W) of the conductive material included in the first positive active material layer PC1 ) and the ratio of the content of the conductive material included in the second positive active material layer (W PC2 ) may each independently be 10 weight% or less.

[0032] In a battery cell according to one embodiment of the present application, under condition ii), the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer may include the same material.

[0033] In a battery cell according to one embodiment of the present application, under condition ii), the content ratio (W) of the positive active material included in the first positive active material layer PA1 ) and the ratio of the content of the positive active material included in the second positive active material layer (W PA2 ) difference (W PA1 -W PA2 The absolute value of ) can be 3 weight% or more.

[0034] In a battery cell according to one embodiment of the present application, under condition ii), the content ratio (W) of the positive active material included in the first positive active material layer PA1 ) and the ratio of the content of the positive active material included in the second positive active material layer (W PA2 ) can each independently be 80 weight% or more.

[0035] A battery cell according to one embodiment of the present application comprises a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein the negative electrode comprises a first negative electrode and a second negative electrode, wherein the first negative electrode comprises a first negative electrode active material layer and the second negative electrode comprises a second negative electrode active material layer, wherein the first negative electrode active material layer and the second negative electrode active material layer each comprise a negative electrode active material, a negative electrode binder, and a conductive material, and wherein the first negative electrode and the second negative electrode may satisfy at least one of the following conditions.

[0036] [condition]

[0037] Condition iv) at least one constituent element or content ratio of the main compound among the cathode active material included in the first cathode active material layer and the main compound among the cathode active material included in the second cathode active material layer are different, or condition v) at least one content ratio of the cathode active material, cathode binder, and conductive material included in the first cathode active material layer and the second cathode active material layer is different, or condition vi) the loading amount (LW3) of the first cathode active material composition forming the first cathode active material layer and the loading amount (LW4) of the second cathode active material composition forming the second cathode active material layer are different.

[0038] In a battery cell according to one embodiment of the present application, under condition v), the content ratio (W) of the conductive material included in the first negative electrode active material layer NC1 ) and the ratio of the content of the conductive material included in the second cathode active material layer (W NC2 ) difference (W NC1 -W NC2 ) may be 3 weight% or more.

[0039] In a battery cell according to one embodiment of the present application, under condition v), the content ratio (W) of the negative active material included in the first negative active material layer NA1 ) and the ratio of the content of the cathode active material included in the second cathode active material layer (W NA2 ) difference (W NA1 -W NA2 The absolute value of ) can be 3 weight% or more. Effects of the invention

[0040] A battery cell according to one example of the present application can have an excellent capacity retention rate, high current output, and appropriate capacity by combining an electrode responsible for high capacity and an electrode responsible for high current output. In addition, a battery cell according to one example of the present application can flexibly respond to rapidly changing current output conditions while having appropriate capacity. Brief explanation of the drawing

[0041] The drawings shown in this application are based on examples of this application, and the ratios of the width, height, or thickness (or height) of each component are intended to explain the disclosure in detail and may differ from the actual. Additionally, in the coordinate system shown in the drawings, each axis may be perpendicular to the others, and the direction indicated by the arrow may be the + direction, and the direction exactly opposite to the direction indicated by the arrow (a direction rotated 180 degrees) may be the - direction. FIGS. 1, FIGS. 2 and FIGS. 3 are each drawings showing at least a portion of a battery cell according to an example of the present application (unidirectional terminal battery cell). FIGS. 4, FIGS. 5, and FIGS. 6 are each drawings showing at least a portion of a battery cell according to an example of the present application (bidirectional terminal battery cell). FIG. 7 is a graph of capacity retention rate obtained by performing the test based on battery cells manufactured in Examples 1 to 3, Comparative Example 1, and Comparative Example 2. FIG. 8 is a charge-discharge graph obtained by performing tests based on battery cells manufactured in Examples 1 to 3, Comparative Example 1, and Comparative Example 2. Figure 9 is a graph of capacity retention rate obtained by performing the test based on the battery cells manufactured in Example 4, Example 5 and Comparative Example 3. Figure 10 is a charge / discharge graph obtained by performing tests based on battery cells manufactured in Example 4, Example 5 and Comparative Example 3. Figure 11 is a graph of capacity retention rate obtained by performing the test based on the battery cells manufactured in Example 6 and Comparative Example 4. Figure 12 is a charge / discharge graph obtained by performing the test based on the battery cells manufactured in Example 6 and Comparative Example 4. FIG. 13 is a graph showing current conditions that simulate the behavior of an electric vehicle or hybrid vehicle in a manner similar to reality to evaluate the capacity retention rate in the present application. Specific details for implementing the invention

[0042] Prior to the detailed description of this application, terms and words used in this specification and claims may not be interpreted as being limited to their ordinary or dictionary meanings. Furthermore, based on the principle that the inventor may appropriately define the concept of terms to best describe their invention, they may be interpreted in a meaning and concept consistent with the technical spirit of this application. The embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of this application and may not represent all of the technical spirit of this application. Therefore, various equivalents and modifications that can replace them may exist at the time of filing this application.

[0043] Identical reference numbers or symbols in each drawing attached to this specification may represent parts or components that perform substantially the same function. For convenience of explanation and understanding, the same reference numbers or symbols may be used to describe different embodiments. That is, even if components having the same reference number are depicted in multiple drawings, the multiple drawings may not all represent a single embodiment.

[0044] In the following description, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprising" or "constituting" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0045] Additionally, in the following description, expressions such as upper side, top, lower side, bottom, side, front, and rear are based on the direction depicted in the drawing, and may be expressed differently if the direction of the object changes.

[0046] Additionally, in this specification and claims, terms including ordinal numbers, such as "first," "second," etc., may be used to distinguish between components. These ordinal numbers are used to distinguish identical or similar components from one another, and the meaning of the terms should not be limited by the use of such ordinal numbers. For example, the order of use or arrangement of components combined with such ordinal numbers should not be limited by the number. If necessary, each ordinal number may be used interchangeably.

[0047] Hereinafter, embodiments of the present application will be described in detail with reference to the attached drawings. However, the scope of the present application is not limited to the embodiments presented. For example, a person skilled in the art who understands the scope of the present application may propose other embodiments that fall within the scope of the scope of the present application by adding, changing, or deleting components, and such are also to be considered to be within the scope of the scope of the present application. In the drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0048] In this specification, the term "battery" may be used interchangeably with "cell." Additionally, the terms "battery" or "cell" may collectively refer to a battery cell, a battery module containing a battery cell, or a battery pack, which are units thereof. Furthermore, the battery cell according to one example of this application may be applied without limitation to any technical field that produces current through an electron transfer material with a positive electrode and a negative electrode. For example, the battery cell according to one example of this application may be applied to the field of batteries as secondary batteries, and may also be applied to fuel cells, etc.

[0049] The term "room temperature" as used in this specification refers to a natural temperature that is not heated or cooled, and may mean, for example, any temperature within the range of 10°C to 30°C, for example, about 15°C or higher, about 18°C ​​or higher, about 20°C or higher, about 23°C or higher, about 27°C or lower, or 25°C. Unless specifically defined in this specification, the unit of temperature is Celsius (°C). Furthermore, among the physical properties mentioned in this specification, if the measured temperature affects the physical property, the physical property may be measured at 25°C unless specifically defined otherwise.

[0050] The term "atmospheric pressure" as used in this specification refers to natural pressure that has not been pressurized or depressurized, typically meaning an atmospheric pressure of about 700 mmHg to 800 mmHg. Unless specifically defined in this specification, the unit of pressure may be mmHg. Furthermore, among the physical properties mentioned in this specification, if the measured pressure affects the physical property, the property may be measured at atmospheric pressure unless specifically defined otherwise.

[0051] As used in this specification, the terms a to b include a and b and mean between a and b. For example, a to b parts by weight include a and b parts by weight and mean between a and b parts by weight.

[0052] FIGS. 1, FIGS. 2 and FIGS. 3 are each drawings showing at least a portion of a battery cell (10) according to an example of the present application (unidirectional terminal battery cell). FIGS. 4, FIGS. 5 and FIGS. 6 are each drawings showing at least a portion of a battery cell according to an example of the present application (bidirectional terminal battery cell).

[0053] The present application can provide a battery cell (10) capable of securing an excellent capacity retention rate, high current output, and appropriate capacity by combining an electrode responsible for high capacity and an electrode responsible for high current output. In addition, the present application can provide a battery cell (10) capable of flexibly responding to rapidly changing current output conditions while having an appropriate capacity.

[0054] In addition, the present application may provide a battery module comprising a battery cell (10) and may provide a battery pack comprising one or more selected from the group consisting of a battery cell (10) and a battery module. Meanwhile, the present application may provide a battery pack comprising a battery cell (10) without a battery module, wherein the battery pack may be referred to as a Cell to Pack. Furthermore, the present application may provide an electric vehicle having excellent output and improved driving range by including a battery cell (10).

[0055] A battery cell (10) may include one or more positive electrodes (100, cathode) and one or more negative electrodes (200, anode). Additionally, the battery cell (10) may have a structure in which a separator (300, separator) is interposed between the positive electrode (100) and the negative electrode (200). The battery cell (10) may include one or more electrode assemblies (1000). The electrode assembly (1000) may include a positive electrode (100), a negative electrode (200), and a separator (300).

[0056] The positive electrode (100) may refer to a reduction electrode where an electron transfer material receives electrons when the battery cell (10) is discharged. The negative electrode (200) refers to an oxidation electrode where an electron transfer material transfers electrons when the battery cell (10) is discharged. The separator (300) refers to a membrane that allows the electron transfer material to pass through while preventing an electrical short circuit between the positive electrode (100) and the negative electrode (200). The electron transfer material is, for example, lithium ions (Li + ), sodium ions (Na + ) or potassium ions (K + It can be.

[0057] The electrode assembly (1000) may be manufactured by winding a long sheet-shaped anode (100), cathode (200), and separator (300) in the longitudinal direction (so-called winding method), or by making a long sheet-shaped separator in the longitudinal direction into a zigzag bend and then alternately inserting an anode (100) and a cathode (200), cut to an appropriate size, into the space formed by the bend (so-called zigzag method). FIGS. 1 and FIGS. 4 illustrate an example of an electrode assembly (1000) manufactured by the zigzag method, but the electrode assembly (1000) may also be manufactured by the winding method, although not shown in the drawings. In addition, methods used in the industry for manufacturing the electrode assembly (1000) other than the winding method or the zigzag method may be applied.

[0058] A battery cell (10) can be manufactured by electrically connecting each electrode tab and electrode lead (400) of an electrode assembly (1000) and embedding it in a case (500) together with an electrolyte. In the electrode assembly (1000), the positive electrode tabs (110a, 120a) and the positive electrode lead (410) can be electrically connected, and the negative electrode tab (200a) and the negative electrode lead (420) can be electrically connected.

[0059] A battery cell (10) may include an electrode terminal (600) having a structure that is part of or electrically connected to an electrode lead (400) and protrudes from the edge of a case (500). The electrode terminal (600) may include a positive terminal (610) that is part of or electrically connected to a positive lead (410) and a negative terminal (620) that is part of or electrically connected to a negative lead (420). FIGS. 1 to 3 illustrate a battery cell (10) in which the positive terminal (610) and the negative terminal (620) protrude in the same direction, and a battery cell (10) with such a structure may be referred to as a unidirectional terminal battery cell (10). FIGS. 4 to 6 illustrate a battery cell (10) in which the positive terminal (610) and the negative terminal (620) protrude in opposite directions, and a battery cell (10) with such a structure may be referred to as a bidirectional terminal battery cell (10). The direction of the terminal (600) is not specifically limited and its position may vary depending on the need and design.

[0060] The anode (100) may include a plurality of individual anodes with distinct physical properties. The individual anodes may be described in this specification as a first anode (110) and a second anode (120), etc. That is, the anode (100) may include a first anode (110) and a second anode (120) with distinct physical properties. Distinguishing physical properties may mean that there is a difference in the physical properties measured by the battery cell after manufacturing it into a battery cell. Specifically, it may mean that there is a difference in the physical properties of the battery cell when only the anode is the first anode (110) or the second anode (120), and the cathode, electrolyte, and physical property measurement method are all the same. Meanwhile, it is obvious to a person skilled in the art that the anode (100) may further include a third anode, etc., with physical properties distinct from the first anode (110) and the second anode (120). In the following description, the first anode (110) and the second anode (120) are described, but additional individual anodes such as the third anode may include configurations corresponding to the first anode (110) and the second anode (120), and the description thereof may be referred to.

[0061] One of the first anode (110) and the second anode (120) can generate a relatively high current output. Additionally, one of the first anode (110) and the second anode (120) can have a relatively high capacity.

[0062] Additionally, if one of the first anode (110) and the second anode (120) generates a relatively high current output, the other may have a relatively high capacity. As will be described later, in this specification, the first anode (110) may generate a higher current output than the second anode (120), and the second anode (120) may have a higher capacity than the first anode (110).

[0063] The first positive electrode (110) may include a first positive active material layer (110b). The first positive electrode (110) may include a first positive current collector (not shown) and a first positive active material layer (110b) formed on one or both sides of the first positive current collector. The first positive active material layer (110b) may be formed as a single layer or multi-layer structure independently on each side of the first positive current collector. Additionally, an area in the first positive electrode (110) where the first positive active material layer (110b) is not formed may be referred to as a first positive non-existent portion (110c). Meanwhile, the first positive electrode (110) may include a main body portion comprising the first positive active material layer (110b) and the first positive non-existent portion (110c), and may include a first positive tab (110a) extending from one edge of the main body portion.

[0064] Considering the electrode process, the first positive tab (110a) and the first positive non-positive portion (110c) may be part of the first positive current collector. The material used for the first positive tab (110a) and the first positive non-positive portion (110c) may be the same as the material of the first positive current collector. The type, size, and shape of the first positive current collector are not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery cell (10). The first positive current collector may include one or more selected from the group consisting of aluminum, stainless steel, nickel, titanium, and materials surface-treated with metal (e.g., nickel, titanium, or silver) or carbon, and preferably may include aluminum.

[0065] The first positive current collector may have an appropriate thickness considering the capacity of the battery cell (10), for example, 1 μm to 500 μm or less, 5 μm to 100 μm or less, or 8 μm to 30 μm or less.

[0066] The second anode (120) may include a second anode tab (120a), a second anode active material layer (120b), and a second anode non-active portion (120c), similar to the first anode (110). The description of the configuration of the second anode (120) may refer to the description of the corresponding configuration of the first anode (110) without contradiction.

[0067] The first anode tab (110a) of the first anode (110) and the second anode tab (120a) of the second anode (120) can be connected to the same anode lead (410). The first anode tab (110a) and the second anode tab (120a) can be electrically connected to the anode lead (410). If there are multiple first anodes (110) and second anodes (120), each first anode tab (110a) and each second anode tab (120a) can be electrically connected to the same anode lead (410). By combining the electrode responsible for high capacity and the electrode responsible for high current output, an excellent capacity retention rate, high current output, and appropriate capacity can be secured. The method of electrical connection may be to align the first anode tab (110a) and the second anode tab (120a) and then weld them to the anode lead (410), and pressure may be applied during welding.

[0068] In this specification, the meaning of being electrically connected may refer to a state in which an electrical circuit is formed when objects to be connected are connected by a connecting means, thereby allowing current to flow through each connected object. The connecting means is not particularly limited as long as electrical connection is possible, but it may be direct contact between objects to be connected or a wire through which current can flow.

[0069] The physical properties of the first anode (110) and the second anode (120) can be distinguished by the characteristics of their respective anode active material layers (110b, 120b). The distinguishing physical properties of the first anode (110) and the second anode (120) can be attributed to their respective anode active material layers (110b, 120b).

[0070] The first positive active material layer (110b) and the second positive active material layer (120b) may each include a positive active material, a positive binder, and a conductive material. The positive active material may include a compound capable of reversibly intercalating and deintercalating lithium ions, sodium ions, or potassium ions. The positive binder may include a compound capable of improving the internal binding strength of each positive active material layer (110b, 120b) and improving the adhesion strength of each positive active material layer (110b, 120b) to each positive current collector. The conductive material may include a compound capable of improving the conductivity and ion or electron mobility of each positive active material layer (110b, 120b).

[0071] Meanwhile, each positive active material layer (110b, 120b) is formed by each positive active material composition, and the positive active material layer (110b, 120b) can be formed by applying the positive active material composition onto each positive current collector and then drying it. Unlike the positive active material layer (110b, 120b), the positive active material composition may further include a solvent for processability. In this specification, drying may refer to a process in which the solvent included in the positive active material composition is included in an amount of 1% by weight or less, 0.5% by weight or less, or 0.1% by weight or less relative to the total weight, or is not included at all (i.e., 0% by weight). That is, the positive active material layer (110b, 120b) may refer to a state in which the positive active material composition has been dried. The drying method is not particularly limited and may be performed, for example, by hot air or infrared irradiation. Additionally, the coating can be performed according to known methods, for example, by using a slot die, doctor blade method, dip method, reverse roll method, direct roll method, gravure method, extrusion method, or brush coating method. Additionally, the positive active material composition can be applied in an appropriate loading amount considering the thickness of the desired positive active material layer (110b, 120b). Additionally, the positive active material layer (110b, 120b) can be rolled to achieve miniaturization of the battery cell (10) and higher energy density. The rolling can be performed according to known methods, for example, through a rolling jig.

[0072] The first positive active material layer (110b) may be formed from the first positive active material composition, and the second positive active material layer (120b) may be formed from the second positive active material composition. The first positive active material composition and the second positive active material composition may each independently include a positive active material, a positive binder, and a conductive material, and may include a solvent. The solvent may be determined according to the material included in the positive active material composition and is not particularly limited as long as it is used in the industry. The solvent may include, for example, an aqueous solvent such as water (pure water or ultrapure water, etc.), an organic solvent, or a mixture of two or more solvents.For example, the solvent is N-methyl-2-pyrrolidone (NMP), propylene carbonate, ethylene carbonate, n-butylene carbonate, dimethyl carbonate, diethyl carbonate, ethylene oxide, gamma-butyrolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, formamide, dimethylformamide, dimethylacetamide, N,N-dimethylaminopropylamine, It may include organic solvents such as acetonitrile, nitromethane, methyl formate, methyl acetate, triethyl phosphate, trimethoxymethane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, methyl propionate, ethyl propionate, or alcohol, or may include aqueous solvents such as water. Preferably, the cathode active material composition may include an organic solvent, specifically N-methyl-2-pyrrolinone.

[0073] Meanwhile, the cathode active material composition may further include a thickener and / or a dispersant, etc., as needed. For example, the cathode active material composition may further include a thickener such as carboxymethyl cellulose (CMC).

[0074] The first anode (110) and the second anode (120) may satisfy at least one of the following conditions. However, if the physical properties of the first anode (110) and the second anode (120) can be distinguished, the first anode (110) and the second anode (120) are not limited to the following conditions and various conditions may be applied.

[0075] [condition]

[0076] Condition i) The positive active material contained in the first positive active material layer (110b) of the first positive electrode (110) and the positive active material contained in the second positive active material layer (120b) of the second positive electrode (120) are different materials.

[0077] Condition ii) The content ratio of one or more of the positive active material, positive binder, and conductive material included in the first positive active material layer (110b) of the first positive electrode (110) and the second positive active material layer (120b) of the second positive electrode (120) is different.

[0078] Condition iii) The loading amount (LW1) of the first positive active material composition forming the first positive active material layer (110b) of the first positive electrode (110) and the loading amount (LW2) of the second positive active material composition forming the second positive active material layer (120b) of the second positive electrode (120) are different.

[0079] As described above, in addition to the above conditions, there may also be conditions such as the type of anode binder included in the first anode active material layer (110b) and the type of anode binder included in the second anode active material layer (120b) being different, or the type of conductive material being different. Furthermore, there may also be conditions such as the thickness (D1) of the first anode active material layer (110b) of the first anode (110) and the thickness (D2) of the second anode active material layer (120b) of the second anode (120) being different. In this specification, thickness may be measured using a contact or non-contact (e.g., ultrasonic or laser) thickness measuring device. If the thickness is constant, the value of that constant thickness may refer to the thickness of this specification, and if the thickness is not constant depending on the location, the value of the average thickness may refer to the thickness of this specification. The above average thickness may mean the value obtained by acquiring a thickness profile according to position and dividing the area obtained through the profile (the value obtained by integrating the thickness function according to position over all positions, where the vertical axis is thickness and the horizontal axis is position) by the distance moved for the thickness measurement. That is, if the physical properties of the first anode (110) and the second anode (120) can be distinguished, the condition is not particularly limited.

[0080] In condition i), the fact that the positive active material contained in the first positive active material layer (110b) and the positive active material contained in the second positive active material layer (120b) of the second positive (120) are different materials means that at least one constituent element is different, or even if expressed by the same chemical formula, the ratio of the elements constituting the chemical formula (e.g., molar ratio) is different.

[0081] Meanwhile, lithium, sodium, or potassium compounds used as positive electrode active materials in this specification may have a layered structure, a crystal structure, or a combination thereof. Additionally, in this specification, the term "lithium compound" may encompass all compounds in which auxiliary elements, coating elements, and doping elements are introduced or substituted around a main active element. The main active element may include, for example, one or more selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), and aluminum (Al). Auxiliary elements, coating elements, and doping elements are elements that can be combined with the main active element to improve the structural and chemical stability of the positive electrode active material, and can be distinguished according to the manner in which they are combined with the main active element. Here, being combined with the main active element may include not only forming a chemical bond with the main active element but also existing on the surface of the positive electrode active material or penetrating from the surface. In addition, for example, the auxiliary element, the coating element, and the doping element may each independently include one or more selected from the group consisting of Group 1 elements (excluding lithium), Group 2 elements, Group 13 elements, Group 14 elements, Group 15 elements, Group 16 elements, and transition metals on the periodic table. Specifically, for example, the auxiliary element, the coating element, and the doping element may each independently include one or more selected from the group consisting of sodium (Na), magnesium (Mg), calcium (Ca), yttrium (Y), titanium (Ti), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), iron (Fe), copper (Cu), silver (Ag), zinc (Zn), boron (B), gallium (Ga), carbon (C), silicon (Si), tin (Sn), strontium (Sr), barium (Ba), radium (Ra), phosphorus (P), and zirconium (Zr).

[0082] In this specification, the positive active material may include one or more compounds selected from the group consisting of a compound represented by the following chemical formula P1, a compound represented by the chemical formula P2, and a compound represented by the chemical formula P3.

[0083] [Chemical Formula P1]

[0084] A a M 1x M 2y M 3z O2

[0085] In the chemical formula P1, A is lithium (Li), sodium (Na), or potassium (K), a is 0.5 or more to 1.8 or less, M1, M2, and M3 are one or more selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), chromium (Cr), vanadium (V), niobium (Nb), boron (B), aluminum (Al), copper (Cu), zirconium (Zr), tungsten (W), titanium (Ti), zinc (Zn), gallium (Ga), germanium (Ge), molybdenum (Mo), tantalum (Ta), yttrium (Y), barium (Ba), and hafnium (Hf) so as not to overlap with each other, and x, y, and z are each independently 0 or more to 1 or less, satisfying x+y+z=1.

[0086] [Chemical Formula P2]

[0087] A a M 1x M 2y M 3z (PO4)

[0088] In the chemical formula P2, A is lithium (Li), sodium (Na), or potassium (K), a is 0.8 or more and 1.2 or less, M1, M2, and M3 are one or more selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), chromium (Cr), vanadium (V), niobium (Nb), boron (B), aluminum (Al), copper (Cu), zirconium (Zr), tungsten (W), titanium (Ti), zinc (Zn), gallium (Ga), germanium (Ge), molybdenum (Mo), tantalum (Ta), yttrium (Y), barium (Ba), and hafnium (Hf) so as not to overlap with each other, and x, y, and z are each independently 0 or more and 1 or less, satisfying x+y+z=1.

[0089] [Chemical Formula P3]

[0090] A a M 1x M 2y M 3z (CN)6

[0091] In the chemical formula P3, A is lithium (Li), sodium (Na), or potassium (K), a is 0.8 or more and 2.2 or less, M1, M2, and M3 are one or more selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), chromium (Cr), vanadium (V), niobium (Nb), boron (B), aluminum (Al), copper (Cu), zirconium (Zr), tungsten (W), titanium (Ti), zinc (Zn), gallium (Ga), germanium (Ge), molybdenum (Mo), tantalum (Ta), yttrium (Y), barium (Ba), and hafnium (Hf) so as not to overlap with each other, and x, y, and z are each independently 0 or more and 1 or less, satisfying x+y+z=1.

[0092] In condition i), the positive active material contained in the first positive active material layer (110b) and the positive active material contained in the second positive active material layer (120b) may each independently contain one or more compounds selected from the group consisting of a compound represented by the following chemical formula P1, a compound represented by the chemical formula P2, and a compound represented by the chemical formula P3, and the positive active material contained in the first positive active material layer (110b) and the positive active material contained in the second positive active material layer (120b) may differ in one or more elements selected from the group consisting of A, M1, M2, and M3 in the following chemical formulas P1, P2, and P3, or in one or more numerical values ​​selected from the group consisting of a, x, y, and z. Through this, the physical properties of the first positive (110) and the second positive (120) can be distinguished.

[0093] [Chemical Formula P1]

[0094] A a M 1x M 2y M 3z O2

[0095] [Chemical Formula P2]

[0096] A a M 1x M 2y M 3z (PO4)

[0097] [Chemical Formula P3]

[0098] A a M 1x M 2y M 3z (CN)6

[0099] In chemical formulas P1, P2, and P3, A is lithium (Li), sodium (Na), or potassium (K); M1, M2, and M3 are one or more selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), chromium (Cr), vanadium (V), niobium (Nb), boron (B), aluminum (Al), copper (Cu), zirconium (Zr), tungsten (W), titanium (Ti), zinc (Zn), gallium (Ga), germanium (Ge), molybdenum (Mo), tantalum (Ta), yttrium (Y), barium (Ba), and hafnium (Hf) so as not to overlap; x, y, and z are each independently 0 or greater to 1 or less, satisfying x+y+z=1; in chemical formula P1, a is 0.5 or greater to 1.8 or less; in chemical formula P2, a is 0.8 or greater to 1.2 or less; and chemical formula In P3, a is 0.8 or more to 2.2 or less.

[0100] In condition i), the positive active material contained in the first positive active material layer (110b) may not be contained in the second positive active material layer (120b). For example, the positive active material contained in the first positive active material layer (110b) may include a lithium, sodium, or potassium compound containing nickel (Ni) as a constituent element. Additionally, the positive active material contained in the second positive active material layer (120b) may include a lithium, sodium, or potassium compound that does not contain nickel (Ni) as a constituent element.

[0101] In condition i), the positive active material included in the first positive active material layer (110b) may include one or more selected from the group consisting of nickel-cobalt-manganese oxide (NCM), nickel-cobalt-aluminum oxide (NCA), and nickel-cobalt-manganese-aluminum oxide (NCMA). Nickel-cobalt-manganese oxide (NCM), nickel-cobalt-aluminum oxide (NCA), and nickel-cobalt-manganese-aluminum oxide (NCMA) may each be independently bonded with lithium (Li), sodium (Na), or potassium (K).

[0102] Nickel (Ni) is one of the transition metals associated with the output and capacity of a battery cell, and the positive active material included in the first positive active material layer (110b) may have a high nickel content ratio (so-called high nickel). However, if the proportion of nickel (Ni) is simply increased, there is a problem where the storage stability and lifespan stability of the battery cell are rapidly degraded, and side reactions with the electrolyte increase, which may lead to electrolyte consumption. Therefore, the positive active material may be composed of an appropriate amount of cobalt (Co), manganese (Mn), or aluminum (Al), etc., as the main active element.

[0103] A high nickel content ratio may mean that when the total number of moles of the main active element in the cathode active material is 1 mole, the nickel (Ni) is 0.6 moles or more, 0.65 moles or more, 0.7 moles or more, 0.75 moles or more, 0.8 moles or more, 0.82 moles or more, 0.83 moles or more, 0.84 moles or more, 0.85 moles or more, or 0.88 moles or more, or 0.95 moles or less, 0.94 moles or less, 0.93 moles or less, 0.92 moles or less, 0.91 moles or less, or 0.9 moles or less.

[0104] In condition i), the positive active material included in the second positive active material layer (120b) may include one or more selected from the group consisting of cobalt oxide (LCO), manganese oxide (LMO), and iron phosphate (LFP). Cobalt oxide (LCO), manganese oxide (LMO), and iron phosphate (LFP) may each be independently bonded with lithium (Li), sodium (Na), or potassium (K).

[0105] It is known that the positive active material that can be included in the first positive active material layer (110b) can generate a relatively high current output compared to the positive active material that can be included in the second positive active material layer (120b). Therefore, the first positive (110) can generate a high current output compared to the second positive (120).

[0106] Meanwhile, it is known that the positive active material that can be included in the second positive active material layer (120b) can have a relatively high capacity compared to the positive active material that can be included in the first positive active material layer (110b). Therefore, the second positive (120) can have a high capacity compared to the first positive (110). By combining the first positive (110) and the second positive (120) having these characteristics and electrically connecting them to the same positive lead (410), an excellent capacity retention rate, high current output, and appropriate capacity can be secured.

[0107] Although not specifically limited, for example, in condition i), the positive active material contained in the first positive active material layer (110b) and the positive active material contained in the second positive active material layer (120b) are different, while other conditions may be substantially the same.

[0108] For example, one or more or all of the positive active material, binder, and conductive material included in the first positive active material layer (110b) and the second positive active material layer (120b), respectively, may have substantially the same content ratio. Here, a substantially the same content ratio means that the absolute value of the difference in the content ratio of each component included in the first positive active material layer (110b) and the second positive active material layer (120b) may be 1% or less, 0.5% or less, or 0.1% or less. In this specification, a content ratio may mean the weight percentage of the material contained relative to the total weight.

[0109] For example, in condition i), the ratio of the content of the positive active material (W) included in the first positive active material layer (110b) PA1 ) and the ratio of the content of the positive active material included in the second positive active material layer (120b) (W PA2 ) difference (W PA1 -W PA2The absolute value of ) may be 1% or less, 0.5% or less, or 0.1% or less. In addition, under condition i), the content ratio (W) of the anode binder included in the anode active material layer (110b) is PB1 ) and the ratio of the content of the anode binder included in the second anode active material layer (120b) (W PB2 ) difference (W PB1 -W PB2 The absolute value of ) may be 1% or less, 0.5% or less, or 0.1% or less. In addition, under condition i), the content ratio (W) of the conductive material included in the 1 positive active material layer (110b) PC1 ) and the ratio of the content of the conductive material included in the second positive active material layer (120b) (W PC2 ) difference (W PC1 -W PC2 The absolute value of ) may be 1% or less, 0.5% or less, or 0.1% or less.

[0110] Although not specifically limited, for example in condition i), the positive active material included in the first positive active material layer (110b) and the second positive active material layer (120b) may each independently be included in an amount of 80 wt% or more, 81 wt% or more, 82 wt% or more, 83 wt% or more, 84 wt% or more, 85 wt% or more, 86 wt% or more, 87 wt% or more, 88 wt% or more, 89 wt% or more, 90 wt% or more, 91 wt% or more, 92 wt% or more, 93 wt% or more, 94 wt% or more, 95 wt% or more, or 96 wt% or more, or 99 wt% or less, or 98 wt% or less, relative to the total weight. The content ratio of the positive active material may be within a range formed by appropriately selecting the upper and lower limits mentioned above. If the content ratio of the positive active material satisfies the above range, it is possible to secure an appropriate energy capacity while generating excellent current output. In addition, when a single anode (100) is used without individual anodes, the content of the anode active material included in the anode active material layer can be referenced from the above. Below, when a single anode (100) is used, the type and content of each component included in the anode active material layer can be referenced.

[0111] Although not specifically limited, for example in condition i), the positive binder included in the first positive active material layer (110b) and the second positive active material layer (120b) may each be independently included in an amount of 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, or 5 parts by weight or more, or 20 parts by weight or less, 19 parts by weight or less, 18 parts by weight or less, 17 parts by weight or less, 16 parts by weight or less, 15 parts by weight or less, 14 parts by weight or less, 13 parts by weight or less, 12 parts by weight or less, 11 parts by weight or less, or 10 parts by weight or less. The content ratio of the positive binder may be within a range formed by appropriately selecting the upper and lower limits mentioned above. If the content ratio of the positive binder satisfies the above range, stability can be ensured by increasing the internal binding force of the positive active material layer and improving the adhesion with the positive current collector.

[0112] In addition, for example, the positive binder included in the first positive active material layer (110b) and the second positive active material layer (120b) in condition i) is independently polyvinylidene fluoride (PVDF), polyvinyl alcohol, styrene butadiene rubber (SBR), polyethylene oxide, carboxyl methyl cellulose (CMC), cellulose acetate, cellulose acetate butylate, cellulose acetate propionate, cyanoethylpullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, It may include one or more selected from the group consisting of polymethylmethacrylate, polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, and polyarylate. However, it is not limited thereto.The anode binders included in the first anode active material layer (110b) and the second anode active material layer (120b) may each preferably include one or more selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinyl alcohol, styrene butadiene rubber (SBR), and polyethylene oxide. Here, polyvinylidene fluoride (PVDF) may include not only monopolyvinylidene fluoride but also copolymers copolymerized with hexafluoropropene (HFP) or chlorotrifluoroethylene (CTFE).

[0113] Although not specifically limited, for example in condition i), the conductive material included in the first positive active material layer (110b) and the second positive active material layer (120b) may each be independently included in an amount of 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, or 5 parts by weight or more, or 20 parts by weight or less, 19 parts by weight or less, 18 parts by weight or less, 17 parts by weight or less, 16 parts by weight or less, 15 parts by weight or less, 14 parts by weight or less, 13 parts by weight or less, 12 parts by weight or less, 11 parts by weight or less, or 10 parts by weight or less. The content ratio of the conductive material may be within a range formed by appropriately selecting the upper and lower limits mentioned above. If the content ratio of the conductive material satisfies the above range, better conductivity may be provided.

[0114] Additionally, for example, the conductive material included in the first positive active material layer (110b) and the second positive active material layer (120b) in condition i) is not particularly limited as long as it is independently used in the art, and may include carbon-based conductive materials such as graphite, carbon black, acetylene black, ketjen black, graphene, carbon nanotubes (CNT), vapor-grown carbon fiber (VGCF), and carbon fiber, and / or metal-based conductive materials such as perovskite materials such as tin, tin oxide, titanium oxide, LaSrCoO3, and LaSrMnO3. The carbon nanotubes (CNT) may include one or more selected from the group consisting of multi-walled carbon nanotubes (MWCNT) and single-walled carbon nanotubes (SWCNT) depending on the number of walls.

[0115] In condition ii), the content ratio (W) of the conductive material included in the first positive active material layer (110b) of the first positive electrode (110) PC1 ) is the content ratio (W) of the conductive material included in the second positive active material layer (120b) of the second positive electrode (120). PC2 It can be larger than ). As the conductive material can improve conductivity and the mobility of ions or electrons as described above, increasing the content of the conductive material may be advantageous for current output. On the other hand, increasing the content of the conductive material may be disadvantageous in terms of capacity because, conversely, the ratio of the content of the positive active material decreases. That is, the physical properties of the first positive (110) and the second positive (120) can be distinguished by varying the content of the conductive material included in their respective positive active material layers (110b, 120b).

[0116] In condition ii), the content ratio (W) of the conductive material included in the first positive active material layer (110b) of the first positive electrode (110) PC1) and the ratio of the content of the conductive material (W) included in the second positive active material layer (120b) of the second positive electrode (120). PC2 ) difference (W PC1 -W PC2 ) may be 3 wt% or more, 3.2 wt% or more, 3.4 wt% or more, 3.6 wt% or more, 3.8 wt% or more, or 4 wt% or more, or 9.5 wt% or less, 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, or 5 wt% or less. Difference in the content ratio of the conductive material (W PC1 -W PC2 The absolute value of ) may be within a range formed by appropriately selecting the aforementioned upper and lower limits. That is, the physical properties of the first anode (110) and the second anode (120) can be distinguished by varying the content of the conductive material included in their respective anode active material layers (110b, 120b).

[0117] In condition ii), the content ratio (W) of the conductive material included in the first positive active material layer (110b) of the first positive electrode (110) PC1 ) and the ratio of the content of the conductive material (W) included in the second positive active material layer (120b) of the second positive electrode (120). PC2 Each of the above may independently be 10 wt% or less, 9.5 wt% or less, 9 wt% or less, 8.5 wt% or less, 8 wt% or less, 7.5 wt% or less, 7 wt% or less, 6.5 wt% or less, 6 wt% or less, 5.5 wt% or less, or 5 wt% or less relative to the total weight, or 0.1 wt% or more, 0.5 wt% or more, or 1 wt% or more. The content ratio of the conductive material may be within a range formed by appropriately selecting the aforementioned upper and lower limits. The type of conductive material may refer to the contents described in condition i) above.

[0118] In condition ii), the positive active material contained in the first positive active material layer (110b) of the first positive electrode (110) and the positive active material contained in the second positive active material layer (120b) of the second positive electrode (120) may contain the same material. Here, the same material may mean a lithium compound in which the main active element is the same. That is, even if the ratio of elements within the lithium compound (e.g., molar ratio) is different, if the main active element is the same, it can be considered the same material. For example, a lithium nickel-cobalt-manganese oxide (NCM) in which nickel (Ni):cobalt (Co):manganese (Mn) is 8:1:1 (mol ratio) and a lithium nickel-cobalt-manganese oxide (NCM) in which nickel (Ni):cobalt (Co):manganese (Mn) is 6:2:2 (mol ratio) can be considered the same material in condition ii) because the main active elements are nickel, cobalt, and manganese.

[0119] In condition ii), the positive active material included in the first positive active material layer (110b) of the first positive electrode (110) and the positive active material included in the second positive active material layer (120b) of the second positive electrode (120) are the same material and may include one or more selected from the group consisting of lithium nickel-cobalt-manganese oxide (NCM), lithium nickel-cobalt-aluminum oxide (NCA), lithium nickel-cobalt-manganese-aluminum oxide (NCMA), lithium cobalt oxide (LCO), lithium manganese oxide (LMO), and lithium iron phosphate (LFP). For details regarding the positive active material, refer to the content described in condition i) above.

[0120] In condition ii), the content ratio (W) of the positive active material included in the first positive active material layer (110b) of the first positive electrode (110). PA1 ) and the ratio of the content of the positive active material (W) contained in the second positive active material layer (120b) of the second positive electrode (120). PA2 ) difference (W PA1 -W PA2The absolute value of ) may be 3 wt% or more, 3.5 wt% or more, 4 wt% or more, 4.5 wt% or more, 5 wt% or more, 5.5 wt% or more, 6 wt% or more, 6.5 wt% or more, 7 wt% or more, 7.5 wt% or more, or 8 wt% or more, or, although not specifically limited, may be 9.5 wt% or less, 9 wt% or less, or 8.5 wt% or less. In condition ii), the difference in the content ratio of the cathode active material (W PA1 -W PA2 The absolute value of ) may be within a range formed by appropriately selecting the aforementioned upper and lower limits.

[0121] Although not specifically limited, for example in condition ii), the positive active material contained in the first positive active material layer (110b) and the second positive active material layer (120b) may each independently be included in an amount of 80 wt% or more, 81 wt% or more, 82 wt% or more, 83 wt% or more, 84 wt% or more, 85 wt% or more, 86 wt% or more, 87 wt% or more, 88 wt% or more, 89 wt% or more, 90 wt% or more, 91 wt% or more, 92 wt% or more, 93 wt% or more, 94 wt% or more, 95 wt% or more, or 96 wt% or more, or 99 wt% or less, or 98 wt% or less, relative to the total weight. The content ratio of the positive active material may be within a range formed by appropriately selecting the upper and lower limits mentioned above. If the content ratio of the positive active material satisfies the above range, it is possible to secure an appropriate energy capacity while generating excellent current output.

[0122] Although not specifically limited, for example in condition ii), the positive binder included in the first positive active material layer (110b) and the second positive active material layer (120b) may each be independently included in an amount of 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, or 5 parts by weight or more, or 20 parts by weight or less, 19 parts by weight or less, 18 parts by weight or less, 17 parts by weight or less, 16 parts by weight or less, 15 parts by weight or less, 14 parts by weight or less, 13 parts by weight or less, 12 parts by weight or less, 11 parts by weight or less, or 10 parts by weight or less. The content ratio of the positive binder may be within a range formed by appropriately selecting the upper and lower limits mentioned above. If the content ratio of the positive binder satisfies the above range, stability can be ensured by increasing the internal binding force of the positive active material layer and improving the adhesion with the positive current collector. For the type of anode binder, refer to the contents described in condition i) above.

[0123] Meanwhile, the first anode (110) and the second anode (120) are CP when n is 100 in the following formula R. R,n It can be distinguished as follows. The second anode (120) is compared to the first anode (110) in the following formula R when n is 100 CP. R,n This could be higher.

[0124] [Formula R]

[0125] CP R,n = CP n / CP1×100

[0126] In formula R, CP nn represents the n-cycle discharge capacity, and CP1 represents the 1-cycle discharge capacity. The method of measuring the cycle discharge capacity is not specifically limited as long as it is used in the industry. For example, the cycle discharge capacity can be measured by charging at 0.3C to a voltage corresponding to SOC98 (charging voltage) under constant current / constant voltage (CC / CV) conditions while maintaining 25°C, then cutting off at 0.05C, and then discharging at 0.3C to a voltage corresponding to SOC4 (discharging voltage) under constant current (CC) conditions, and measuring the discharge capacity. Alternatively, for example, the cycle discharge capacity can be measured according to the capacity retention rate evaluation method in the [Method for Measuring Physical Properties] below (see FIG. 13). In addition, the cycle discharge capacity according to the formula R can be measured for a battery cell containing the first anode (110) or the second anode (120). Here, for comparison purposes, a battery cell can be manufactured by varying only the type of anode while keeping the cathode, electrolyte, and physical property measurement method the same, and then measuring the cycle discharge capacity by referring to the aforementioned method.

[0127] The second anode (120) is the CP when n is 100 in the following formula R compared to the first anode (110). R,n To make this higher, the constituent elements of the positive active material included in the first positive active material layer (110b) and the positive active material included in the second positive active material layer (120b), or the ratio of their content, can be appropriately selected differently. Additionally, the ratio of at least one of the positive active material, positive binder, and conductive material included in each of the first positive active material layer (110b) and the second positive active material layer (120b) can be appropriately selected differently.

[0128] The ratio (N1 / N2) of the number of first anodes (N1) and the number of second anodes (N2) may be 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, or 5 or less, or 0.1 or more, 0.5 or more, 1 or more, 2 or more, 3 or more, or 4 or more. The ratio (N1 / N2) of the number of first anodes (110) and second anodes (120) may be within a range formed by appropriately selecting the upper and lower limits mentioned above. If the ratio (N1 / N2) of the number of first anodes (110) and second anodes (120) satisfies the aforementioned range, an excellent capacity retention rate, high current output, and appropriate capacity can be secured by combining individual anodes with distinct physical properties. Meanwhile, the number of first anodes (N1) and the number of second anodes (N2) can be measured for the first anode (110) and the second anode (120) connected to the same anode lead (410).

[0129] The number of the first anode (N1) is the total number of anodes (N T It may be 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, or 50% or less, or 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, or 45% or more (excluding 100%). The number of the first anode (N1) may be within a range formed by appropriately selecting the aforementioned upper and lower limits. The total number of anodes (N T ) refers to the total number of anodes, such as the first anode (110) and the second anode (120), connected to the same anode lead (410), and the number of first anodes (N1) refers to the number of first anodes (110) connected to the anode lead (410).

[0130] The number of second anodes (N2) is the total number of anodes (N TIt may be 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, or 50% or less, or 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, or 45% or more (excluding 100%). The number of the second anode (N2) may be within a range formed by appropriately selecting the aforementioned upper and lower limits. The total number of anodes (N T ) refers to the total number of anodes, such as the first anode (110) and the second anode (120), connected to the same anode lead (410), and the number of second anodes (N2) refers to the number of second anodes (120) connected to the anode lead (410).

[0131] Total number of anodes (N T The number of first anodes (N1) and second anodes (N2) relative to ) is naturally influenced by the number of first anodes (110) and second anodes (120) relative to each other. For example, in an anode (100) containing only first anodes (110) and second anodes (120), the first anode (110) is the total number of anodes (N T If the number is prepared as about 60% of the total number of anodes (N), the second anode (120) is the total number of anodes (N T It is prepared with about 40% of the number compared to ).

[0132] The cathode (200) may include a cathode active material layer (200b). The cathode (200) may include a cathode current collector (not shown) and a cathode active material layer (200b) formed on one or both sides of the cathode current collector. The cathode active material layer (200b) may be formed as a single layer or multi-layer structure independently on each side of the cathode current collector. Additionally, an area of ​​the cathode (200) where the cathode active material layer (200b) is not formed may be referred to as a cathode non-existent portion (200c). Meanwhile, the cathode (200) may include a main body portion comprising the cathode active material layer (200b) and the cathode non-existent portion (200c), and may include a cathode tab (200a) extending from one edge of the main body portion.

[0133] Considering the electrode process, the negative tab (200a) and the negative non-negative portion (200c) may be part of the negative current collector. The material used for the negative tab (200a) and the negative non-negative portion (200c) may be the same as the material of the negative current collector. The type, size, and shape of the negative current collector are not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery cell (10). The negative current collector may include one or more selected from the group consisting of copper, stainless steel, nickel, titanium, and materials surface-treated with a metal (e.g., nickel, titanium, or silver) or carbon, and preferably may include copper.

[0134] The negative current collector may have an appropriate thickness considering the capacity of the battery cell (10), for example, 1 μm to 500 μm or less, 5 μm to 100 μm or less, or 8 μm to 50 μm or less.

[0135] The cathode (200) may include a plurality of individual cathodes with distinct physical properties. The individual cathodes may be described in this specification as a first cathode and a second cathode, etc. That is, the cathode (200) may include a first cathode and a second cathode with distinct physical properties. Distinguishing physical properties may mean that there is a difference in the physical properties measured by the battery cell after manufacturing it into a battery cell. Specifically, it may mean that there is a difference in the physical properties of the battery cell when only the cathode is the first cathode or the second cathode, and the anode, electrolyte, and physical property measurement method are all the same. Meanwhile, it is obvious to a person skilled in the art that the cathode (200) may further include a third cathode, etc., with physical properties distinct from the first cathode and the second cathode. In the following description, the first cathode and the second cathode will be described, but the additional individual cathode, such as the third cathode, may include a configuration corresponding to the first cathode and the second cathode, and the description thereof may be referenced.

[0136] One of the first cathode and the second cathode may have a relatively high capacity. Additionally, one of the first cathode and the second cathode may generate a relatively high current output. Furthermore, if one of the first cathode and the second cathode generates a relatively high current output, the other may have a relatively high capacity. For example, in this specification, the first cathode may generate a higher current output compared to the second cathode, and the second cathode may have a higher capacity compared to the first cathode.

[0137] The first cathode and the second cathode may refer to the structure of the aforementioned cathode (200) unless there is a contradiction, and each may independently include a cathode active material layer. That is, the first cathode may include a first cathode active material layer, and the second cathode may include a second cathode active material layer.

[0138] The first cathode may include a first cathode tab, and the second cathode may include a second cathode tab. The first cathode tab and the second cathode tab may be connected to the same cathode lead (420). The first cathode tab and the second cathode tab may be electrically connected to the cathode lead (420). If there are multiple first cathodes and second cathodes, each first cathode tab and each second cathode tab may be electrically connected to the same cathode lead (420). By combining cathodes with distinct physical properties, an excellent capacity retention rate, high current output, and appropriate capacity can be secured. The method of electrical connection may be to align the second cathode tab and the second cathode tab and then weld them to the cathode lead (420), and pressure may be applied during welding.

[0139] The physical properties of the first cathode and the second cathode can be distinguished by the characteristics of their respective cathode active material layers. The distinguishing physical properties of the first cathode and the second cathode can be attributed to their respective cathode active material layers.

[0140] The first negative electrode active material layer and the second negative electrode active material layer may each include a negative electrode active material, a negative electrode binder, and a conductive material. The negative electrode active material may include a compound capable of reversibly intercalating and deintercalating lithium ions, sodium ions, or potassium ions. The negative electrode binder may include a compound capable of improving the internal binding strength of each negative electrode active material layer and improving the adhesion strength of each negative electrode active material layer to each negative electrode current collector. The conductive material may include a compound capable of improving the conductivity and ion or electron mobility of each negative electrode active material layer.

[0141] Each negative active material layer is formed by each negative active material composition, and the negative active material layer can be formed by applying the negative active material composition onto each negative current collector and then drying it. Unlike the negative active material, the negative active material composition may further include a solvent for processability. The negative active material layer may refer to the state in which the negative active material composition is dried. The drying method is not particularly limited and can be performed, for example, by hot air or infrared irradiation. Additionally, the application can be performed according to known methods, for example, by using a slot die, doctor blade method, dip method, reverse roll method, direct roll method, gravure method, extrusion method, or brush application method. Furthermore, the negative active material composition can be applied in an appropriate loading amount considering the desired thickness of the negative active material layer. Additionally, the negative active material layer can be rolled to achieve miniaturization of the battery cell (10) and higher energy density. The above rolling can be performed according to a known method, for example, through a rolling jig.

[0142] The first cathode active material layer may be formed from the first cathode active material composition, and the second cathode active material layer may be formed from the second cathode active material composition. The first cathode active material composition and the second cathode active material composition may each independently include a cathode active material, a cathode binder, and a conductive material, and may include a solvent. The solvent may include, for example, an aqueous solvent such as water (pure water or ultrapure water, etc.), an organic solvent, or a mixture of two or more solvents.For example, the solvent may include an aqueous solvent such as water, or N-methyl-2-pyrrolidone (NMP), propylene carbonate, ethylene carbonate, n-butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butyrolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, formamide, dimethylformamide, acetonitrile, nitromethane, methyl formate, methyl acetate It may include organic solvents such as acetate, triethyl phosphate, trimethoxymethane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, methyl propionate, ethyl propionate, or alcohol. Preferably, the cathode active material composition may include an aqueous solvent, specifically water (pure or ultrapure water).

[0143] Meanwhile, the cathode active material composition may further include a thickener and / or a dispersant, etc., as needed. For example, the cathode active material composition may include a cellulose-based compound as a thickener, and the cellulose-based compound may include one or more selected from the group consisting of, for example, carboxyl methyl cellulose (CMC), cellulose acetate, cellulose acetate butylate, and cellulose acetate propionate.

[0144] The first cathode and the second cathode may satisfy at least one of the following conditions. However, if the physical properties of the first cathode and the second cathode can be distinguished, the first cathode and the second cathode are not limited to the following conditions and various conditions may be applied.

[0145] [condition]

[0146] Condition iv) The main compound among the cathode active material included in the first cathode active material layer of the first cathode and the main compound among the cathode active material included in the second cathode active material layer of the second cathode have at least one different constituent element or different content ratio.

[0147] Condition v) The content ratio of one or more of the cathode active material, cathode binder, and conductive material contained in the first cathode active material layer of the first cathode and the second cathode active material layer of the second cathode is different.

[0148] Condition vi) The loading amount (LW3) of the first cathode active material composition forming the first cathode active material layer of the first cathode and the loading amount (LW4) of the second cathode active material composition forming the second cathode active material layer of the second cathode are different.

[0149] As described above, in addition to the above conditions, there may also be conditions such as the type of cathode binder included in the first cathode active material layer and the type of cathode binder included in the second cathode active material layer being different, or the type of conductive material being different. Furthermore, there may also be conditions such as the thickness (D3) of the first cathode active material layer of the first cathode and the thickness (D4) of the second cathode active material layer of the second cathode being different. In other words, as long as the physical properties of the first cathode and the second cathode can be distinguished, the conditions are not particularly limited.

[0150] Meanwhile, in this specification, the negative electrode active material may include one or more selected from the group consisting of silicon-based compounds, carbon-based compounds, and additional negative electrode active materials, and these may include a state in which a metal is doped or coated. The metal element used for doping or coating may include, for example, one or more selected from the group consisting of lithium (Li), magnesium (Mg), calcium (Ca), iron (Fe), titanium (Ti), vanadium (V), and aluminum (Al). In this specification, silicon-based compounds may refer to compounds containing a silicon element (Si) that are capable of reversible intercalation and deintercalation of lithium ions, sodium ions, or potassium ions, unless limited. Additionally, in this specification, carbon-based compounds may refer to compounds containing a carbon element (C) that are capable of reversible intercalation and deintercalation of lithium ions, sodium ions, or potassium ions, unless limited. When both silicon elements (Si) and carbon elements (C) are included, it can be classified as a silicon-based compound.

[0151] Silicon-based compounds are, for example, SiOx(0 <x≤2)의 구조식을 가진 화합물을 포함할 수 있다. 또한, 실리콘계 화합물은 전술한 바와 같이 결정질 탄소 또는 비정질 탄소와 실리콘이 결합된 실리콘 탄화물을 포함할 수 있다. 상기 결정질 탄소는 무정형, 판상, 플레이크(flake), 구형 또는 섬유형의 천연 흑연 또는 인조 흑연과 같은 흑연을 예로 들 수 있다. 또한, 상기 비정질 탄소는 소프트 카본, 하드 카본 또는 소성된 코크스로 예를 들 수 있다. 탄소계 화합물은 예를 들면, 인조 흑연, 천연 흑연 또는 흑연화 탄소 섬유와 같은 흑연 재료를 포함할 수 있고, 다른 분류로써 연화 탄소(soft carbon) 또는 경화 탄소(hard carbon)과 같은 저결정성 탄소; 및 무정형, 판상, 인편상, 구형 또는 섬유형의 천연 흑연 또는 인조 흑연, 키시흑연(Kish graphite), 열분해 탄소(pyrolytic carbon), 액정피치계 탄소섬유(mesophase pitch based carbon fiber), 탄소 미소구체(mesocarbon microbeads), 액정피치 (Mesophase pitches) 또는 석유와 석탄계 코크스(petroleum or coal tar pitch derived cokes)와 같은 고결정성 탄소로 이루어지는 군에서 선택된 하나 이상을 포함할 수 있다. 부가 음극 활물질은 알루미늄(Al), 주석(Sn), 납(Pb), 아연(Zn), 비스무트(Bi), 인듐(In), 마그네슘(Mg), 갈륨(Ga), 카드뮴(Cd) 및 실리콘(Si)으로 이루어지는 군에서 선택된 둘 이상의 원소를 포함하는 합금과 같은 금속 합금 화합물; 또는 바나듐 산화물 또는 리튬 바나듐 산화물과 같이 리튬을 도프(dope) 및 탈도프할 수 있는 금속 산화물(실리콘계 화합물 및 탄소계 화합물로 분류된 화합물은 제외함)로 이루어지는 군에서 선택된 하나 이상을 포함할 수 있다.In addition, when a single cathode (200) is used without individual cathodes, the type of cathode active material included in the cathode active material layer (200b) can be referenced from the above description.

[0152] In condition iv), the term "main compound" refers to the compound with the largest weight ratio among the compounds included in the negative electrode active material. The physical properties of the first negative electrode and the second negative electrode can be distinguished by different types of the main compound of the negative electrode active material included in their respective negative electrode active material layers. For example, the main compound among the negative electrode active materials included in the first negative electrode active material layer may be a silicon-based compound, and the main compound among the negative electrode active materials included in the second negative electrode active material layer may be a carbon-based compound.

[0153] In condition iv), even if the main compounds of the negative active material included in the first negative active material layer and the negative active material included in the second negative active material layer are the same, the physical properties can be distinguished by making the content ratio relative to the total weight of the negative active material different. For example, the negative active material included in the first negative active material layer may be 40 wt% silicon-based compound and 60 wt% carbon-based compound, and the negative active material included in the second negative active material layer may be 10 wt% silicon-based compound and 90 wt% carbon-based compound.

[0154] Although not specifically limited, for example in condition iv), only the negative active material contained in the first negative active material layer and the negative active material contained in the second negative active material layer are different, while other conditions may be substantially the same. For example, one or more or all of the negative active material, binder, and conductive material contained in the first negative active material layer and the second negative active material layer, respectively, may have substantially the same content ratio. Here, "substantially the same content ratio" means that the absolute value of the difference in the content ratio of the components contained in the first negative active material layer and each component contained in the second negative active material layer may be 1% or less, 0.5% or less, or 0.1% or less. Here, "content ratio" may mean the weight percentage of the material contained relative to the total weight.

[0155] For example, in condition iv), the content ratio of the cathode active material included in the first cathode active material layer (W NA1 ) and the ratio of the content of the cathode active material included in the second cathode active material layer (W NA2 ) difference (W NA1 -W NA2 The absolute value of ) may be 1% or less, 0.5% or less, or 0.1% or less. In addition, under condition iv), the content ratio of the cathode binder included in 1 cathode active material layer (W NB1 ) and the ratio of the content of the cathode binder included in the second cathode active material layer (W NB2 ) difference (W NB1 -W NB2 The absolute value of ) may be 1% or less, 0.5% or less, or 0.1% or less. In addition, under condition iv), the content ratio of the conductive material included in 1 cathode active material layer (W PC1 ) and the ratio of the content of the conductive material included in the second cathode active material layer (W NC2 ) difference (W NC1 -W NC2 The absolute value of ) may be 1% or less, 0.5% or less, or 0.1% or less.

[0156] Although not specifically limited, for example in condition iv), the negative active material included in the first negative active material layer and the second negative active material layer may each independently be included in an amount of 80 wt% or more, 81 wt% or more, 82 wt% or more, 83 wt% or more, 84 wt% or more, 85 wt% or more, 86 wt% or more, 87 wt% or more, 88 wt% or more, 89 wt% or more, 90 wt% or more, 91 wt% or more, 92 wt% or more, 93 wt% or more, 94 wt% or more, 95 wt% or more, or 96 wt% or more, or 99 wt% or less, or 98 wt% or less, relative to the total weight. The content ratio of the negative active material may be within a range formed by appropriately selecting the aforementioned upper and lower limits. If the content ratio of the negative active material satisfies the above range, it is possible to secure an appropriate energy capacity while generating excellent current output. In addition, when a single cathode (200) is used without individual cathodes, the content of the cathode active material included in the cathode active material layer (200b) can be referenced from the above. Below, when a single cathode (200) is used, the type and content of each component included in the cathode active material layer (200b) can be referenced.

[0157] Although not specifically limited, for example in condition iv), the cathode binder included in the first cathode active material layer and the second cathode active material layer may each be independently included in an amount of 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, or 1.5 parts by weight or more, or 10 parts by weight or less, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less, relative to 100 parts by weight of the cathode active material. The content ratio of the cathode binder may be within a range formed by appropriately selecting the upper and lower limits mentioned above. If the content ratio of the cathode binder satisfies the above range, stability can be ensured by increasing the internal binding force of the cathode active material layer and improving the adhesion force with the cathode current collector.

[0158] In addition, for example, in condition iv), the cathode binder included in the first cathode active material layer and the second cathode active material layer is independently styrene butadiene rubber (SBR), polyvinylidene fluoride (PVDF), polyvinyl alcohol, polyethylene oxide, cyanoethylpullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, polymethylmethacrylate, polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, It may include one or more selected from the group consisting of polyethylene-co-vinyl acetate copolymer and polyarylate. Preferably, the negative electrode active material layer may include one or more selected from the group consisting of styrene butadiene rubber (SBR), polyvinylidene fluoride (PVDF), and polyvinyl alcohol as a negative electrode binder. However, it is not limited thereto. Additionally, it may be preferable that the negative electrode binders included in the first negative electrode active material layer and the second negative electrode active material layer each independently include styrene butadiene rubber (SBR).

[0159] In addition, when a single cathode (200) is used without individual cathodes, the type and content of the cathode binder included in the cathode active material layer (200b) can be referenced from the above description.

[0160] Although not specifically limited, for example in condition iv), the first cathode active material layer and the second cathode active material layer may further include a thickener together with the cathode binder. The thickener included in the first cathode active material layer and the second cathode active material layer may each independently be included in an amount of 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, or 1.5 parts by weight or more, or 10 parts by weight or less, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less, relative to 100 parts by weight of the cathode active material. Alternatively, the thickeners included in the first cathode active material layer and the second cathode active material layer may each be independently included in an amount of 50 parts by weight or more, 55 parts by weight or more, 60 parts by weight or more, 65 parts by weight or more, 70 parts by weight or more, 75 parts by weight or more, 80 parts by weight or more, 85 parts by weight or more, 90 parts by weight or more, 95 parts by weight or more, 100 parts by weight or more, or 200 parts by weight or less, 190 parts by weight or less, 180 parts by weight or less, 170 parts by weight or less, 160 parts by weight or less, 150 parts by weight or less, 140 parts by weight or less, 130 parts by weight or less, 120 parts by weight or less, or 110 parts by weight or less. The content ratio of the thickener may be within a range formed by appropriately selecting the aforementioned upper and lower limits. If the content ratio of the thickener satisfies the above range, it is combined with the cathode binder to increase the internal binding strength of the cathode active material layer and improve the adhesion with the cathode current collector, thereby ensuring stability.

[0161] Although not specifically limited, for example in condition iv), the conductive material included in the first cathode active material layer and the second cathode active material layer may each independently be included in an amount of 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, or 5 parts by weight or more, or 20 parts by weight or less, 19 parts by weight or less, 18 parts by weight or less, 17 parts by weight or less, 16 parts by weight or less, 15 parts by weight or less, 14 parts by weight or less, 13 parts by weight or less, 12 parts by weight or less, 11 parts by weight or less, or 10 parts by weight or less, relative to 100 parts by weight of the cathode active material. The content ratio of the conductive material may be within a range formed by appropriately selecting the aforementioned upper and lower limits. If the content ratio of the conductive material satisfies the above range, better conductivity can be provided.

[0162] In addition, for example, the conductive materials included in the first cathode active material layer and the second cathode active material layer in condition i) are not particularly limited as long as they are independently used in the art, and may include carbon-based conductive materials such as graphite, carbon black, acetylene black, ketjen black, graphene, carbon nanotubes (CNT), vapor-grown carbon fiber (VGCF), and carbon fiber, and / or metal-based conductive materials such as perovskite materials such as tin, tin oxide, titanium oxide, LaSrCoO3, and LaSrMnO3. The carbon nanotubes (CNT) may include one or more selected from the group consisting of multi-walled carbon nanotubes (MWCNT) and single-walled carbon nanotubes (SWCNT) depending on the number of walls.

[0163] In addition, when a single cathode (200) is used without individual cathodes, the type and content of the conductive material included in the cathode active material layer (200b) can be referenced from the above description.

[0164] Under condition v), the content ratio of the conductive material (W) included in the first cathode active material layer of the first cathode NC1 ) and the ratio of the content of the conductive material included in the second cathode active material layer of the second cathode (W NC2 ) difference (W NC1 -W NC2 ) may be 3 wt% or more, 3.2 wt% or more, 3.4 wt% or more, 3.6 wt% or more, 3.8 wt% or more, or 4 wt% or more, or 9.5 wt% or less, 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, or 5 wt% or less. Difference in the content ratio of the conductive material (W NC1 -W NC2 The absolute value of ) may be within a range formed by appropriately selecting the aforementioned upper and lower limits. That is, the physical properties of the first cathode and the second cathode can be distinguished by varying the content of the conductive material included in each cathode active material layer.

[0165] Under condition v), the content ratio of the conductive material (W) included in the first cathode active material layer of the first cathode NC1 ) and the ratio of the content of the conductive material included in the second cathode active material layer of the second cathode (W NC2 Each of the above may independently be 10 wt% or less, 9.5 wt% or less, 9 wt% or less, 8.5 wt% or less, 8 wt% or less, 7.5 wt% or less, 7 wt% or less, 6.5 wt% or less, 6 wt% or less, 5.5 wt% or less, or 5 wt% or less relative to the total weight, or 0.1 wt% or more, 0.5 wt% or more, or 1 wt% or more. The content ratio of the conductive material may be within a range formed by appropriately selecting the upper and lower limits mentioned above. For the type of conductive material, refer to the contents described in condition iv) mentioned above.

[0166] Under condition v), the cathode active material contained in the first cathode active material layer of the first cathode and the cathode active material contained in the second cathode active material layer of the second cathode may contain the same material. Here, the term "same material" may refer to compounds of the same series. That is, even if the ratios between elements within the compound (e.g., molar ratios) differ, if they belong to the same series when classified based on whether they are silicon-based, carbon-based, metal alloy compounds excluding these, or metal oxides, they can be considered the same material.

[0167] Under condition v), the content ratio (W) of the cathode active material included in the first cathode active material layer of the first cathode. NA1 ) and the ratio of the content of the cathode active material included in the second cathode active material layer of the second cathode (W NA2 ) difference (W NA1 -W NA2 The absolute value of ) may be 3 wt% or more, 3.5 wt% or more, 4 wt% or more, 4.5 wt% or more, 5 wt% or more, 5.5 wt% or more, 6 wt% or more, or, although not specifically limited, 9.5 wt% or less, 9 wt% or less, 8.5 wt% or less, or 8 wt% or less. Under condition v), the difference in the content ratio of the negative electrode active material (W NA1 -W NA2 The absolute value of ) may be within a range formed by appropriately selecting the aforementioned upper and lower limits.

[0168] Although not specifically limited, for example in condition v), the negative active material included in the first negative active material layer and the second negative active material layer may each independently be included in an amount of 80 wt% or more, 81 wt% or more, 82 wt% or more, 83 wt% or more, 84 wt% or more, 85 wt% or more, 86 wt% or more, 87 wt% or more, 88 wt% or more, 89 wt% or more, 90 wt% or more, 91 wt% or more, 92 wt% or more, 93 wt% or more, 94 wt% or more, 95 wt% or more, or 96 wt% or more, or 99 wt% or less, or 98 wt% or less, relative to the total weight. The content ratio of the negative active material may be within a range formed by appropriately selecting the aforementioned upper and lower limits. If the content ratio of the negative active material satisfies the above range, it is possible to secure an appropriate energy capacity while generating excellent current output.

[0169] Although not specifically limited, for example in condition v), the cathode binder included in the first cathode active material layer and the second cathode active material layer may each be independently included in an amount of 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, or 1.5 parts by weight or more, or 10 parts by weight or less, 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less, relative to 100 parts by weight of the cathode active material. The content ratio of the cathode binder may be within a range formed by appropriately selecting the upper and lower limits mentioned above. If the content ratio of the cathode binder satisfies the above range, stability can be ensured by increasing the internal binding force of the cathode active material layer and improving the adhesion with the cathode current collector. The type of cathode binder may refer to the contents described in condition iv) mentioned above.

[0170] Meanwhile, the first cathode and the second cathode are CP when n is 100 in the following formula R. R,nIt can be distinguished as follows. Compared to the first cathode, the second cathode is CP when n is 100 in the following formula R. R,n This could be higher.

[0171] [Formula R]

[0172] CP R,n = CP n / CP1×100

[0173] In formula R, CP n represents the n-cycle discharge capacity, and CP1 represents the 1-cycle discharge capacity. The method of measuring the cycle discharge capacity can be referenced from the above.

[0174] The second cathode, compared to the first cathode, is CP when n is 100 in the following formula R. R,n To increase this, the type or mixing ratio of the negative active material included in the first negative active material layer and the negative active material included in the second negative active material layer can be appropriately selected differently. Additionally, the content ratio of at least one of the negative active material, negative binder, and conductive material included in each of the first negative active material layer and the second negative active material layer can be appropriately selected differently.

[0175] Number of first cathodes (N n1 ) and the number of the second cathode (N n2 The ratio of )(N n1 / N n2 ) may be 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, or 5 or less, or 0.1 or more, 0.5 or more, 1 or more, 2 or more, 3 or more, or 4 or more. The ratio of the number of the first cathode and the second cathode (N n1 / N n2 ) may be within a range formed by appropriately selecting the aforementioned upper and lower limits. The ratio of the number of the first cathode and the second cathode (N n1 / N n2If ) satisfies the aforementioned range, excellent capacity retention rate, high current output, and appropriate capacity can be secured by combining individual cathodes with distinct physical properties. Meanwhile, the number of the first cathodes (N n1 ) and the number of the second cathode (N n2 ) can be measured by targeting the first cathode and the second cathode connected to the same cathode lead (420).

[0176] Number of first cathodes (N n1 ) is the total number of cathodes (N nT It may be 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, or 50% or less, or 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, or 45% or more (excluding 100%). The number of the first cathode (N n1 ) may be within a range formed by appropriately selecting the aforementioned upper and lower limits. The total number of cathodes (N nT ) refers to the total number of cathodes, such as the first cathode and the second cathode, connected to the same cathode lead (420), and the number of the first cathodes (N n1 ) means the number of first cathodes connected to the cathode lead (420).

[0177] Number of second cathodes (N n2 ) is the total number of cathodes (N nT It may be 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, or 50% or less, or 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, or 45% or more (excluding 100%). The number of the second cathode (N n2 ) may be within a range formed by appropriately selecting the aforementioned upper and lower limits. The total number of cathodes (N nT) refers to the total number of cathodes, such as the first cathode and the second cathode, connected to the same cathode lead (420), and the number of the second cathode (N n2 ) means the number of second cathodes connected to the cathode lead (420).

[0178] Total number of cathodes (N nT Number of first cathodes relative to ) (N n1 ) and the number of the second cathode (N n2 ) is naturally affected by the number of the first cathode and the second cathode relative to each other. For example, in a cathode (200) containing only the first cathode and the second cathode, the first cathode is the total number of cathodes (N nT If provided in a number approximately 60% of the total number of cathodes (N nT It is prepared with about 40% of the number compared to ).

[0179] The battery cell (10) may include a separator (300). The separator is not particularly limited as long as it is used in the industry, and it is desirable that it has low resistance to ion movement of the electrolyte and excellent wettability of the electrolyte (especially the electrolyte). The separator may be, for example, a porous polymer film, a porous polymer film made of a polyolefin material such as an ethylene polymer, a propylene polymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, or an ethylene / methacrylate copolymer, or a laminated structure of two or more layers thereof.

[0180] The battery cell (10) may include a case (500). In the battery cell (10), an electrode assembly may be embedded in an internal space formed by the case (500). Additionally, the battery cell (10) may include an electrolyte, and the electrolyte may be embedded in an internal space formed by the case (500).

[0181] The case (500) may have various shapes, and depending on these shapes, the battery cell (10) may be classified into cylindrical, prismatic, coin, or pouch types. The case (500) is not particularly limited, but may include aluminum (Al) to ensure rigidity, and if it includes aluminum, it can protect the built-in electrode assembly from external shocks or vibrations.

[0182] An electrolyte is a substance that enables the movement of electron transfer substances between an anode (100) and a cathode (200). The electrolyte may be in a liquid or solid state at room temperature. If the electrolyte is in a liquid state at room temperature, it may be called an electrolyte solution.

[0183] The electrolyte may include lithium salts used in the industry unless specifically limited. For example, in the lithium salt, the anion is F - , Cl - , Br - , I - , NO3 - , N(CN)2 - , BF4 - , ClO4 - , PF6 - , (CF3)2PF4 - , (CF3)3PF3 - , (CF3)4PF2 - , (CF3)5PF - , (CF3)6P - , CF3SO3 - , CF3CF2SO3 - , (CF3SO2)2N - , (FSO2)2N - ,　 CF3CF2(CF3)2CO - , (CF3SO2)2CH - , (SF5)3C - , (CF3SO2)3C - , CF3(CF2)7SO3 - , CF3CO2 - , CH3CO2 - , SCN - and (CF3CF2SO2)2N- It may include one or more selected from the group consisting of. If necessary, the electrolyte may include a sodium salt, and the anion in the sodium salt may refer to the anion in the aforementioned lithium salt. Below, the lithium salt will be described as a representative example.

[0184] The electrolyte may contain a lithium salt at a concentration of 0.1 M or more, 0.2 M or more, 0.3 M or more, 0.4 M or more, 0.5 M or more, 0.6 M or more, 0.7 M or more, 0.8 M or more, 0.9 M or more, or 1 M or more, or 10 M or less, 9 M or less, 8 M or less, 7 M or less, 6 M or less, 5 M or less, 4 M or less, 3 M or less, 2 M or less, or 1.5 M or less. Here, M represents molar concentration (mol / L). The electrolyte may contain a lithium salt such that the concentration is within the range formed by appropriately selecting the aforementioned upper and lower limits.

[0185] The electrolyte may further include an organic solvent. The organic solvent may include one or more selected from the group consisting of carbonate-based solvents, ether-based solvents, and ester-based solvents. The electrolyte may further include a suitable solvent considering appropriate viscosity and electrical conductivity.

[0186] The carbonate-based solvent may include one or more selected from the group consisting of cyclic carbonate-based solvents and linear carbonate-based solvents. The cyclic carbonate-based solvent may include, for example, one or more selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate (1,2-BC), 2,3-butylene carbonate (2,3-BC), 1,2-pentylene carbonate (1,2-PTC), 2,3-pentylene carbonate (2,3-PTC), and vinylene carbonate (VC). Linear carbonate-based solvents may include, for example, one or more selected from the group consisting of methyl carbonate, ethyl carbonate, dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), ethylmethyl carbonate (EMC), methylpropyl carbonate (MPC), and ethylpropyl carbonate (EPC).

[0187] The ether-based solvent may include one or more selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methylethyl ether, methylpropyl ether, and ethylpropyl ether.

[0188] The ester-based solvent may include one or more selected from the group consisting of linear ester-based solvents and cyclic ester-based solvents. For example, the linear ester compound may include one or more selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate. Additionally, for example, the cyclic ester compound may include one or more selected from the group consisting of, for example, gamma-buturolactone, gamma-valerolactone, gamma-caprolactone, sigma-valerolactone, and epsilon-caprolactone.

[0189] The electrolyte may additionally include one or more selected from the group consisting of sulfite-based compounds, sulfone-based compounds, nitrile-based compounds, and borate-based compounds, as needed.

[0190] Meanwhile, if the electrolyte is solid at room temperature, a solid electrolyte layer containing the solid electrolyte is interposed between the positive electrode (100) and the negative electrode (200) to transfer electron transfer substances while simultaneously performing the function of a separator. In this case, the battery cell (10) can be referred to as an all-solid battery. The solid electrolyte may include any used in the industry without limitation.

[0191] The battery cell (10) can be manufactured in a conventional manner. Additionally, the battery cell (10) can be manufactured in a conventional manner including all of the aforementioned configurations.

[0192] A battery module or battery pack according to one example of the present application may include one or more battery cells (10). Additionally, an electric device according to one example of the present application may include a battery cell (10), and the electric device is a device that operates through power generated from the battery cell (10), and may be, for example, a mobile phone, a home appliance, an electric vehicle, a hybrid vehicle, or an energy storage system (ESS).

[0193] The battery cell (10) can be widely applied in green technology fields such as electric vehicles, battery charging stations, and other solar and wind power generation that utilize batteries. In addition, the cell (10) according to one example of the present application can be applied to eco-friendly electric vehicles or hybrid vehicles to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0195] [Methods for Measuring Physical Properties]

[0196] The physical properties mentioned below were measured as follows.

[0197] 1. Capacity Retention Evaluation

[0198] The front and rear surfaces of the manufactured battery cell were wrapped with an aluminum (Al) plate jig, and the plate jig was bolted to secure the battery cell and prevent movement. Here, the battery cell was charged and discharged under the current conditions shown in Fig. 13 while maintaining a temperature of 25°C, and the discharge capacity (1-cycle discharge capacity) was measured. Fig. 13 represents current conditions that simulate the actual behavior of an electric or hybrid vehicle; this allows for results closer to reality compared to measuring the capacity retention rate under conventional constant current / constant voltage (CC / CV) conditions. In Fig. 13, the dotted line area (continuous measurement time: 5,000 to 9,000 seconds) is displayed in an enlarged view. Subsequently, after repeating the charge and discharge n times (n > 1, n is an integer) under the same current conditions, the n-cycle discharge capacity was measured. Additionally, the capacity retention rate (CP), which is the ratio of the n-cycle discharge capacity to the 1-cycle discharge capacity, was measured. R,n ) was measured using the following formula R and represented as a graph.

[0199] [Formula R]

[0200] CP R,n = CP n / CP1×100

[0201] In formula R, CP n represents the n-cycle discharge capacity, and CP1 represents the 1-cycle discharge capacity. The unit of the above discharge capacity is mAh.

[0202] 2. Charge / Discharge Graph

[0203] The manufactured battery cell was charged and discharged under 0.5 C constant current / constant voltage (CC / CV) conditions in a voltage range of 2.5 V to 4.3 V under conditions maintained at 25 ℃, and a charge / discharge graph was shown.

[0205] In the following, embodiments of the present application are further described with reference to specific examples. The embodiments and comparative examples are merely illustrative of the present application and are not intended to limit the appended claims. It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope and spirit of the present application. Furthermore, it is obvious that such variations and modifications fall within the scope of the appended claims.

[0206] [Preparation Example]

[0207] Preparation Example 1 - Preparation of the first anode

[0208] The first anode was manufactured by applying a first anode active material composition, which forms a first anode active material layer, to both sides of an aluminum foil in an appropriate loading amount, drying the aluminum foil coated with the first anode active material composition at about 120°C to form the first anode active material layer, and then rolling and cutting to form a first anode tab.

[0209] The first positive active material composition above was prepared by mixing a positive active material (A), a positive binder (B), and a conductive material (C) in a weight ratio of 96:2:2 (A:B:C) in a sufficient amount of solvent.

[0210] The above positive active material (A) used lithium nickel-cobalt-manganese oxide (NCM) having a weight ratio of nickel (Ni):cobalt (Co):manganese (Mn) = 8:1:1. The above positive binder (B) used polyvinylidene fluoride (PVdF). The above conductive material (C) used carbon black. In addition, the above solvent used N-methyl-2-pyrrolidone (NMP).

[0211] Preparation Example 2 - Preparation of the first anode

[0212] The first anode was prepared in the same manner as in Preparation Example 1, except that the first anode active material composition was prepared by mixing the anode active material (A), the anode binder (B), and the conductive material (C) in a sufficient amount of solvent in a weight ratio of 90:5:5 (A:B:C).

[0213] Preparation Example 3 - Preparation of the second anode

[0214] The second anode was manufactured by applying a second anode active material composition, which forms a second anode active material layer, to both sides of an aluminum foil in an appropriate loading amount, drying the aluminum foil coated with the second anode active material composition at about 120°C to form the second anode active material layer, and then rolling and cutting to form a second anode tab.

[0215] The above second positive active material composition was prepared by mixing a positive active material (A), a positive binder (B), and a conductive material (C) in a weight ratio of 96:2:2 (A:B:C) in a sufficient amount of solvent.

[0216] The above positive active material (A) used was lithium iron phosphate (LFP), and the positive binder (B), conductive material (C), and solvent used were the same as those used in Preparation Example 1.

[0217] Preparation Example 4 - Preparation of the second anode

[0218] The second anode was manufactured by applying a second anode active material composition, which forms a second anode active material layer, to both sides of an aluminum foil in an appropriate loading amount, drying the aluminum foil coated with the second anode active material composition at about 120°C to form the second anode active material layer, and then rolling and cutting to form a second anode tab.

[0219] The above second positive active material composition was prepared by mixing a positive active material (A), a positive binder (B), and a conductive material (C) in a weight ratio of 98:1:1 (A:B:C) in a sufficient amount of solvent.

[0220] The above positive active material (A) used was lithium nickel-cobalt-manganese oxide (NCM) having a weight ratio of nickel (Ni):cobalt (Co):manganese (Mn) = 8:1:1. The positive binder (B), conductive material (C), and solvent used were the same as those used in Preparation Example 1.

[0221] Preparation Example 5 - Preparation of the second anode

[0222] The second anode was prepared in the same manner as in Preparation Example 4, except that the second anode active material composition was prepared by mixing the second anode active material (A), the first anode binder (B), and the conductive material (C) in a weight ratio of 96:2:2 (A:B:C) in a sufficient amount of solvent.

[0223] Preparation Example 6 - Preparation of Cathode

[0224] The cathode was manufactured by applying a cathode active material composition, which forms a cathode active material layer, to both sides of a copper foil in an appropriate loading amount, drying the copper foil coated with the cathode active material composition at about 80°C to form a cathode active material layer, and then rolling and cutting to form a cathode tab.

[0225] The above cathode active material composition was prepared by mixing artificial graphite (A), cathode binder (B), conductive material (C), and thickener (D) in a weight ratio of 95:1.5:2:1.5 (A:B:C:D) in a sufficient amount of deionized water.

[0226] The above cathode binder (B) used styrene-butadiene rubber. The above conductive material (C) used carbon black. The above thickener (D) used carboxymethyl cellulose.

[0227] Preparation Example 7 - Preparation of the first cathode

[0228] The first cathode was manufactured by applying a first cathode active material composition, which forms a first cathode active material layer, to both sides of a copper foil in an appropriate loading amount, drying the copper foil coated with the first cathode active material composition at about 80°C to form a first cathode active material layer, and then rolling and cutting to form a first cathode tab.

[0229] The first cathode active material composition above was prepared by mixing artificial graphite (A), cathode binder (B), conductive material (C), and thickener (D) in a weight ratio of 92:1.5:5:1.5 (A:B:C:D) in a sufficient amount of deionized water.

[0230] The above cathode binder (B) used styrene-butadiene rubber. The above conductive material (C) used carbon black. The above thickener (D) used carboxymethyl cellulose.

[0231] Preparation Example 8 - Preparation of the second cathode

[0232] The second cathode was manufactured by applying a second cathode active material composition, which forms a second cathode active material layer, to both sides of a copper foil in an appropriate loading amount, drying the copper foil coated with the second cathode active material composition at about 80°C to form a second cathode active material layer, and then rolling and cutting to form a second cathode tab.

[0233] The above second cathode active material composition was prepared by mixing artificial graphite (A), cathode binder (B), conductive material (C), and thickener (D) in a weight ratio of 98:0.5:1:0.5 (A:B:C:D) in a sufficient amount of deionized water.

[0234] The above cathode binder (B) used styrene-butadiene rubber. The above conductive material (C) used carbon black. The above thickener (D) used carboxymethyl cellulose.

[0235] Preparation Example 9 - Preparation of Cathode

[0236] A cathode was prepared in the same manner as in Preparation Example 6, except that the cathode active material composition was prepared by mixing artificial graphite (A), cathode binder (B), conductive material (C), and thickener (D) in a ratio of 94:1.5:3:1.5 (A:B:C:D) in a sufficient amount of deionized water.

[0237] [Example]

[0238] Example 1.

[0239] An electrode assembly was prepared by interposing a polyolefin separator (thickness: 15 μm, porosity: 40%) between the first anode prepared in Preparation Example 1 or the second anode prepared in Preparation Example 3 and the cathode prepared in Preparation Example 6. Meanwhile, the second anode prepared in Preparation Example 3 has a CP according to Formula R compared to the first anode prepared in Preparation Example 1. R,100 This had a larger value. In addition, the first positive tab of the first positive and the second positive tab of the second positive were welded to the same positive lead to be fixed and electrically connected, and the negative tab of the negative was welded to the negative lead to be fixed and electrically connected. An electrode assembly with the electrode leads connected was placed in a pouch case, an electrolyte was injected into the pouch case, and then sealed to manufacture a pouch-type battery cell.

[0240] Here, the ratio of the number of the first anode (N1) and the number of the second anode (N2) is set to 1:3 (N1:N2), and the number of the first anode (N1) is the total number of anodes (N TIt was about 25% of ) and the number of the second anode (N2) was the total number of anodes (N T It was about 75% compared to ).

[0241] Specifically, the manufactured electrode assembly includes a structure stacked in the order of a first anode-cathode-second anode-cathode-second anode-cathode-second anode-cathode-second anode, and a separator is interposed between the first anode and cathode and the second anode and cathode.

[0242] In addition, the above electrolyte was prepared to be in a liquid state at room temperature and was prepared by dissolving LiPF6, a lithium salt, in an organic solvent mixed with ethylene carbonate (EC) and ethylmethyl carbonate (EMC) in a volume ratio of 25:75 (EC:EMC) to have a concentration of 1.0 M (at 25 ℃).

[0243] Example 2.

[0244] The ratio of the number of first anodes (N1) to the number of second anodes (N2) was set to 2:2 (N1:N2), and the number of first anodes (N1) was the total number of anodes (N T It was about 50% of ), and the number of the second anode (N2) was the total number of anodes (N T A battery cell was manufactured in the same manner as in Example 1, except that the electrode assembly was manufactured at approximately 50% of the size of the electrode assembly.

[0245] In addition, the specifically manufactured electrode assembly includes a stacked structure (so-called zigzag structure) in the order of first anode-cathode-second anode-cathode-first anode-cathode-second anode, and a separator is interposed between the first anode and cathode and between the second anode and cathode.

[0246] Example 3.

[0247] The ratio of the number of first anodes (N1) to the number of second anodes (N2) was set to 3:1 (N1:N2), and the number of first anodes (N1) was the total number of anodes (NT It was about 75% of ), and the number of the second anode (N2) was the total number of anodes (N T A battery cell was manufactured in the same manner as Example 1, except that the electrode assembly was manufactured at approximately 25% of the size of the electrode assembly.

[0248] In addition, the specifically manufactured electrode assembly includes a structure stacked in the order of a first anode-cathode-first anode-cathode-first anode-cathode-second anode, and a separator is interposed between the first anode and the cathode and between the second anode and the cathode.

[0249] Comparative Example 1.

[0250] An electrode assembly was prepared by interposing a polyolefin separator (thickness: 20 μm, porosity: 40%) between the first anode prepared in Preparation Example 1 and the cathode prepared in Preparation Example 6. Additionally, the first anode tab of the first anode was welded to the anode lead to secure and electrically connect it, and the cathode tab of the cathode was welded to the cathode lead to secure and electrically connect it. An electrode assembly with the connected electrode leads was placed in a pouch case, an electrolyte was injected into the pouch case, and the case was sealed to manufacture a pouch-type battery cell. The total number of anodes (N T ) was performed in the same manner as in Example 1. In addition, the electrolyte used was the same as that used in Example 1.

[0251] Comparative Example 2.

[0252] An electrode assembly was prepared by interposing a polyolefin separator (thickness: 20 μm, porosity: 40%) between the second anode prepared in Preparation Example 3 and the cathode prepared in Preparation Example 6. Additionally, the second anode tab of the second anode was welded to the anode lead to secure and electrically connect it, and the cathode tab of the cathode was welded to the cathode lead to secure and electrically connect it. An electrode assembly with the connected electrode leads was placed in a pouch case, an electrolyte was injected into the pouch case, and the case was sealed to manufacture a pouch-type battery cell. The total number of anodes (N T ) was performed in the same manner as in Example 1. In addition, the electrolyte used was the same as that used in Example 1.

[0254] Example 4.

[0255] An electrode assembly was prepared by interposing a polyolefin separator (thickness: 20 μm, porosity: 40%) between the first anode prepared in Preparation Example 2 or the second anode prepared in Preparation Example 4 and the cathode prepared in Preparation Example 6. Meanwhile, the second anode prepared in Preparation Example 4 has a CP according to Formula R compared to the first anode prepared in Preparation Example 2. R,100 This had a larger value. In addition, the first positive tab of the first positive and the second positive tab of the second positive were welded to the same positive lead to be fixed and electrically connected, and the negative tab of the negative was welded to the negative lead to be fixed and electrically connected. An electrode assembly with the electrode leads connected was placed in a pouch case, an electrolyte was injected into the pouch case, and then sealed to manufacture a pouch-type battery cell.

[0256] Here, the ratio of the number of the first anode (N1) and the number of the second anode (N2) is set to 2:2 (N1:N2), and the number of the first anode (N1) is the total number of anodes (N T It was about 50% of ), and the number of the second anode (N2) was the total number of anodes (N TIt was about 50% compared to ).

[0257] Specifically, the manufactured electrode assembly includes a stacked structure (so-called zigzag structure) in the order of first anode-cathode-second anode-cathode-first anode-cathode-second anode, and a separator is interposed between the first anode and cathode and between the second anode and cathode.

[0258] In addition, the above electrolyte was prepared to be in a liquid state at room temperature and was prepared by dissolving LiPF6, a lithium salt, in an organic solvent mixed with ethylene carbonate (EC) and ethylmethyl carbonate (EMC) in a volume ratio of 25:75 (EC:EMC) to have a concentration of 1.0 M (at 25 ℃).

[0259] Example 5.

[0260] The ratio of the number of first anodes (N1) to the number of second anodes (N2) was set to 3:1 (N1:N2), and the number of first anodes (N1) was the total number of anodes (N T It was about 75% of ), and the number of the second anode (N2) was the total number of anodes (N T A battery cell was manufactured in the same manner as Example 4 above, except that the electrode assembly was manufactured at approximately 25% of the size of the electrode assembly.

[0261] In addition, the specifically manufactured electrode assembly includes a structure stacked in the order of a first anode-cathode-first anode-cathode-first anode-cathode-second anode, and a separator is interposed between the first anode and the cathode and between the second anode and the cathode.

[0262] Comparative Example 3.

[0263] An electrode assembly was prepared by interposing a polyolefin separator (thickness: 20 μm, porosity: 40%) between the second anode prepared in Preparation Example 5 and the cathode prepared in Preparation Example 6. Additionally, the second anode tab of the second anode was welded to the anode lead to secure and electrically connect it, and the cathode tab of the cathode was welded to the cathode lead to secure and electrically connect it. An electrode assembly with the connected electrode leads was placed in a pouch case, an electrolyte was injected into the pouch case, and the case was sealed to manufacture a pouch-type battery cell. The total number of anodes (N T ) was performed in the same manner as in Example 4. In addition, the electrolyte used was the same as that used in Example 4.

[0265] Example 6.

[0266] An electrode assembly was prepared by interposing a polyolefin separator (thickness: 15 μm, porosity: 40%) between the (first) anode prepared in Preparation Example 1 and the first cathode prepared in Preparation Example 7 or the second cathode prepared in Preparation Example 8. Meanwhile, the second cathode prepared in Preparation Example 8 had a CP according to Formula R compared to the first cathode prepared in Preparation Example 7. R,100 This had a larger value. Additionally, the first cathode tab of the first cathode and the second cathode tab of the second cathode were welded to the same cathode lead to be fixed and electrically connected, and the (first) anode tab of the anode was welded to the anode lead to be fixed and electrically connected. An electrode assembly with the electrode leads connected was placed in a pouch case, an electrolyte was injected into the pouch case, and then sealed to manufacture a pouch-type battery cell.

[0267] Here, the number of the first cathodes (N n1 ) and the number of the second cathode (N n2 The ratio of ) is 2:2(N n1 :N n2 It was made so that ), and the number of the first cathode (N n1 ) is the total number of cathodes (NnT It was about 50% compared to ), and the number of the second cathode (N n2 ) is the total number of cathodes (N nT It was about 50% compared to ).

[0268] Specifically, the manufactured electrode assembly includes a structure (so-called zigzag structure) stacked in the order of first cathode-anode-second cathode-anode-first cathode-anode-second cathode manufactured in Example 7, and a separator is interposed between the first cathode and the anode and between the second cathode and the anode.

[0269] In addition, the above electrolyte was prepared to be in a liquid state at room temperature and was prepared by dissolving LiPF6, a lithium salt, in an organic solvent mixed with ethylene carbonate (EC) and ethylmethyl carbonate (EMC) in a volume ratio of 25:75 (EC:EMC) to have a concentration of 1.0 M (at 25 ℃).

[0270] Comparative Example 4.

[0271] An electrode assembly was prepared by interposing a polyolefin separator (thickness: 20 μm, porosity: 40%) between the (first) anode prepared in Preparation Example 1 and the cathode prepared in Preparation Example 9. Additionally, the (first) anode tab of the anode was welded to the anode lead to secure and electrically connect it, and the cathode tab of the cathode was welded to the cathode lead to secure and electrically connect it. An electrode assembly with the electrode leads connected was placed in a pouch case, an electrolyte was injected into the pouch case, and the case was sealed to manufacture a pouch-type battery cell. The total number of cathodes (N nT ) was performed in the same manner as in Example 6. In addition, the electrolyte used was the same as that used in Example 6.

[0273] The results of tests performed based on battery cells manufactured in Examples 1 to 3, Comparative Example 1, and Comparative Example 2 are shown in FIGS. 7 and 8, and the results of tests performed based on battery cells manufactured in Examples 4, 5, Comparative Example 3, and Comparative Example 4 are shown in FIGS. 9 and 10.

[0274] Referring to FIG. 7, it can be seen that Examples 1 to 3 exhibit excellent capacity retention rates, while Comparative Example 1 exhibits a low capacity retention rate. Additionally, referring to FIG. 8, it can be seen that Examples 1 to 3 exhibit excellent output and have appropriate capacity, while Comparative Example 2 has high resistance, a large voltage drop, low current output, and relatively low capacity.

[0275] Referring to FIG. 9, it can be seen that Examples 4 and 5 show a relatively good capacity retention rate. Also, referring to FIG. 10, it can be seen that Examples 4 and 5 show a good output and have a relatively large capacity, while Comparative Example 3 has a relatively low capacity.

[0276] Referring to FIG. 11, it can be seen that Example 6 exhibits a relatively excellent capacity retention rate. Additionally, referring to FIG. 12, it can be seen that Example 6 exhibits excellent output and has a relatively large capacity, while Comparative Example 4 has a relatively low capacity.

[0278] Although various embodiments of the present application have been described in detail above, the scope of the present application is not limited thereto, and it will be obvious to those with average knowledge in the art that various modifications and variations are possible within the scope of the technical concept of the present application as described in the claims. Furthermore, the above-described embodiments may be implemented by deleting some components, and each embodiment may be implemented in combination with one another. Explanation of the symbols

[0279] 10... battery cell 100... positive electrode 110... 1st anode 110a... 1st anode tab 110b... First positive active material layer 110c... First positive non-positive portion 120... Second anode 120a... Second anode tab 120b... Second positive electrode active material layer 120c... Second positive electrode non-positive portion 200... Cathode 200a... Cathode tab 200b... Cathode active material layer 200c... Cathode non-cathode portion 300... Separator 400... Electrode Lead 410... Anode Lead 420... Cathode Lead 500... Case 600... Terminal 610... Positive terminal 620... Negative terminal

Claims

Claim 1 The apparatus comprises an anode, a cathode, and a separator interposed between the anode and the cathode, wherein the anode comprises a first anode and a second anode, wherein the first anode comprises a first anode active material layer and the second anode comprises a second anode active material layer, wherein the first anode active material layer and the second anode active material layer each comprise an anode active material, an anode binder, and a conductive material, and the second anode has a CP when n is 100 in the following formula R compared to the first anode R,n A battery cell in which the above first anode and second anode are higher and satisfy at least one of the following conditions: [Formula R]CP R,n = CP n In the formula R / CP1×100, CP n represents n cycle discharge capacity, CP1 represents 1 cycle discharge capacity, [Condition] Condition i) the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer are different materials, and the positive active material included in the first positive active material layer is not included in the second positive active material layer, or Condition ii) the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer contain the same material, and the content ratio of at least one of the positive active material, positive binder, and conductive material included in the first positive active material layer and the second positive active material layer is different. Claim 2 A battery cell according to claim 1, wherein the first positive electrode includes a first positive electrode tab and the second positive electrode includes a second positive electrode tab, and the first positive electrode tab and the second positive electrode tab are connected to the same positive electrode lead. Claim 3 A battery cell according to claim 1, wherein the ratio (N1 / N2) of the number of first positive electrodes (N1) and the number of second positive electrodes (N2) is 10 or less. Claim 4 In claim 3, the number of the first anode (N1) is the total number of anodes (N T It is 95% or less of ) and the number of the second anode (N2) is the total number of anodes (N T A battery cell that is 5% or more (excluding 100%) relative to ). Claim 5 In claim 1, the cathode comprises a first cathode and a second cathode, wherein the first cathode comprises a first cathode active material layer and the second cathode comprises a second cathode active material layer, wherein the first cathode active material layer and the second cathode active material layer each comprise a cathode active material, a cathode binder, and a conductive material, and the first cathode and the second cathode satisfy the following conditions for a battery cell: [Conditions] Condition iv) At least one constituent element or content ratio of the main compound among the cathode active material included in the first cathode active material layer and the main compound among the cathode active material included in the second cathode active material layer are different, or Condition v) At least one content ratio of the cathode active material, cathode binder, and conductive material included in the first cathode active material layer and the second cathode active material layer is different, or Condition vi) The loading amount (LW3) of the first cathode active material composition forming the first cathode active material layer and the second cathode active material composition forming the second cathode active material layer The loading amount (LW4) is different. Claim 6 In claim 5, the first cathode includes a first cathode tab and the second cathode includes a second cathode tab, and the first cathode tab and the second cathode tab are connected to the same cathode lead, forming a battery cell. Claim 7 A battery cell according to claim 1, wherein, under condition i), the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer are materials having at least one different constituent element, or materials having different compositional ratios of elements constituting the same chemical formula even if expressed by the same chemical formula. Claim 8 In claim 1, under condition i), the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer may each independently include one or more compounds selected from the group consisting of a compound represented by the following chemical formula P1, a compound represented by the chemical formula P2, and a compound represented by the chemical formula P3, and the positive active material included in the first positive active material layer and the positive active material included in the second positive active material layer may differ in one or more elements selected from the group consisting of A, M1, M2, and M3 in the following chemical formulas P1, P2, and P3, or in one or more numerical values ​​selected from the group consisting of a, x, y, and z, in a battery cell: [Chemical Formula P1]A a M 1x M 2y M 3z O2[Chemical Formula P2]A a M 1x M 2y M 3z (PO4) [Chemical formula P3]A a M 1x M 2y M 3z (CN)6 In the above formulas P1, P2, and P3, A is lithium (Li), sodium (Na), or potassium (K), and M1, M2, and M3 are one or more selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), chromium (Cr), vanadium (V), niobium (Nb), boron (B), aluminum (Al), copper (Cu), zirconium (Zr), tungsten (W), titanium (Ti), zinc (Zn), gallium (Ga), germanium (Ge), molybdenum (Mo), tantalum (Ta), yttrium (Y), barium (Ba), and hafnium (Hf) so as not to overlap with each other, and x, y, and z are each independently 0 or more to 1 or less, satisfying x+y+z=1, and in the above formula P1, a is 0.5 or more to 1.8 or less, and in the above formula P2, a is 0.8 or more to It is 1.2 or less, and in the chemical formula P3, a is 0.8 or more to 2.2 or less. Claim 9 In claim 1, under condition i), the content ratio (W) of the positive active material included in the first positive active material layer PA1 ) and the ratio of the content of the positive active material included in the second positive active material layer (W PA2 ) difference (W PA1 -W PA2 A battery cell in which the absolute value of ) is 1 weight% or less. Claim 10 In claim 1, under condition ii), the content ratio (W) of the conductive material included in the first positive electrode active material layer PC1 ) is the content ratio of the conductive material included in the second positive active material layer (W PC2 Battery cell larger than ) Claim 11 In claim 10, under condition ii), the content ratio (W) of the conductive material included in the first positive electrode active material layer PC1 ) and the ratio of the content of the conductive material included in the second positive active material layer (W PC2 ) difference (W PC1 -W PC2 ) is a battery cell with 3 weight percent or more. Claim 12 In claim 10, under condition ii), the content ratio (W) of the conductive material included in the first positive electrode active material layer PC1 ) and the ratio of the content of the conductive material included in the second positive active material layer (W PC2 ) are battery cells each independently having 0.1 wt% or more and 10 wt% or less. Claim 13 delete Claim 14 In claim 1, under condition ii), the content ratio (W) of the positive active material included in the first positive active material layer PA1 ) and the ratio of the content of the positive active material included in the second positive active material layer (W PA2 ) difference (W PA1 -W PA2 A battery cell in which the absolute value of ) is 3 weight% or more. Claim 15 In claim 1, under condition ii), the content ratio (W) of the positive active material included in the first positive active material layer PA1 ) and the ratio of the content of the positive active material included in the second positive active material layer (W PA2 ) are battery cells, each independently 80 weight percent or more. Claim 16 The apparatus comprises an anode, a cathode, and a separator interposed between the anode and the cathode, wherein the cathode comprises a first cathode and a second cathode, wherein the first cathode comprises a first cathode active material layer and the second cathode comprises a second cathode active material layer, wherein the first cathode active material layer and the second cathode active material layer each comprise a cathode active material, a cathode binder, and a conductive material, and the second cathode has a CP when n is 100 in the following formula R compared to the first cathode R,n A battery cell in which the above first cathode and second cathode are higher and satisfy at least one of the following conditions: [Formula R]CP R,n = CP n In the formula R / CP1×100, CP n represents n cycle discharge capacity, CP1 represents 1 cycle discharge capacity, [Condition] Condition iv) at least one constituent element is different between the main compound among the cathode active material included in the first cathode active material layer and the main compound among the cathode active material included in the second cathode active material layer, or Condition v) the cathode active material included in the first cathode active material layer and the cathode active material included in the second cathode active material layer contain the same material, and at least one content ratio among the cathode active material, cathode binder, and conductive material included in the first cathode active material layer and the second cathode active material layer is different. Claim 17 delete Claim 18 delete

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