Method for deactivating outermost negative electrodes, method for manufacturing electrode assembly, and electrode assembly

Abstract

The present invention relates to a method for deactivating a pair of outermost negative electrodes respectively disposed at the uppermost end and the lowermost end of an electrode assembly comprising a plurality of positive electrodes, a plurality of negative electrodes, and a plurality of separators, the method comprising a deactivation step of forming a deactivation region having a predetermined width (w) along an edge of one surface of each outermost negative electrode, wherein in the deactivation step, the width (w) is determined on the basis of the horizontal length of the outermost negative electrode, the vertical length of the outermost negative electrode, and the number of monocells composed of a separator, a negative electrode, a separator, and a positive electrode in the electrode assembly. By providing the method for deactivating outermost negative electrodes, it is possible to provide a clear guide for a deactivation operation of outermost negative electrodes of an electrode assembly.

Description

Method for deactivating the outermost cathode, method for manufacturing an electrode assembly, and electrode assembly

[0001] The present invention relates to a method for deactivating an outermost cathode, a method for manufacturing an electrode assembly, and an electrode assembly manufactured by the method.

[0002] As technological development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. Among such secondary batteries, lithium secondary batteries, which exhibit high energy density and operating potential, long cycle life, and low self-discharge rate, are being commercialized and widely used.

[0003] Furthermore, with growing concern for environmental issues, research is being conducted on electric and hybrid electric vehicles (HEVs) as alternatives to fossil fuel-powered vehicles like gasoline and diesel, a major source of air pollution. While nickel-metal hydride secondary batteries are primarily used as power sources for these vehicles, research into the use of lithium secondary batteries, which boast high energy density and discharge voltage, is actively underway, and some have already been commercialized.

[0004] Secondary batteries are also classified based on the structure of the electrode assembly of the positive electrode / separator / cathode structure. Representative examples include a jelly-roll electrode assembly in which long sheet-shaped positive and negative electrodes are rolled up with a separator in between, a stacked electrode assembly in which a number of positive and negative electrodes cut into units of a predetermined size are sequentially stacked with a separator in between, and a stacked / folded electrode assembly that combines the rolled and laminated types.

[0005] These secondary batteries are generally manufactured by embedding an electrode assembly comprising a positive electrode plate and a negative electrode plate coated with positive and negative electrode active materials and a separator interposed therebetween in a pouch-shaped case made of aluminum laminate sheet.

[0006] The secondary battery manufactured in this way undergoes an activation process for charging and discharging.

[0007] During the activation process, lithium moves between the electrodes, separator, and electrolyte, excluding a pair of outermost cathodes located at the top and bottom of the electrode assembly, and a charge-discharge reaction (hereinafter referred to as the main reaction) occurs.

[0008] Meanwhile, at the outermost cathode, a local reaction occurs that does not participate in the main reaction but is involved in the charging and discharging of the adjacent electrode.

[0009] For example, the outermost cathode is charged as lithium is introduced through diffusion through the electrolyte, and at this time, a potential difference occurs between the edge and the middle of the outermost cathode, causing a side reaction.

[0010] When the proportion of local reactions exceeds a certain level compared to the main reaction, there is a problem of unnecessary electrolyte consumption and unevenness throughout the electrode assembly.

[0011] Previously, to prevent the outermost cathode from participating in local reactions, a deactivation operation was performed by coating the surface or edge of the outermost cathode with an insulating material.

[0012] The deactivation operation can reduce side reactions caused by potential differences by making the potential difference between the edge and the middle part of the outermost cathode equal.

[0013] Although it is advantageous in terms of efficiency to selectively perform the deactivation operation only when the ratio of local reaction to the main reaction is above a certain level, there is currently no clear guideline for determining whether to perform the deactivation operation on the outermost cathode.

[0014] The present invention aims to provide a method for deactivating an outermost cathode, which can provide a clear guide for the deactivation operation of the outermost cathode of an electrode assembly, a method for manufacturing an electrode assembly, and an electrode assembly manufactured from the manufacturing method.

[0015] In order to solve the above problem, according to one embodiment of the present invention, a method for deactivating a pair of outermost cathodes, each of which is disposed at the uppermost and lowermost ends of an electrode assembly including a plurality of anodes, a plurality of cathodes, and a plurality of separators, is provided, comprising a deactivation step of forming a deactivation area having a predetermined width (w) along an edge of one side of the outermost cathode, wherein in the deactivation step, the width (w) is determined based on a horizontal length of the outermost cathode, a vertical length of the outermost cathode, and the number of mono cells composed of a separator, a cathode, a separator, and an anode in the electrode assembly.

[0016] In the above method for deactivating the outermost cathode, in the deactivation step, the width (w) is determined within a range of 0.9P1 to 1.2P1, and the P1 can be calculated by the following equation 1:

[0017] [Formula 1]

[0018]

[0019] In the above formula 1, a1 is the horizontal length of the outermost cathode, b1 is the vertical length of the outermost cathode, and c1 is the number of mono cells composed of a separator, cathode, separator, and anode in the electrode assembly.

[0020] In addition, in the method for deactivating the outermost cathode, the width (w) in the deactivation step can be determined based on the ratio (A / B) of the sum of the areas (A) of the faces of the plurality of cathodes in the electrode assembly and the sum of the areas (B) of the faces of the plurality of anodes.

[0021] In addition, in the method for deactivating the outermost cathode, in the deactivation step, the width (w) is determined within a range of 1.0X1 to 1.25X1 when the ratio (A / B) is 1.1 or more and less than 1.2, and the X1 can be calculated by the following equation 2:

[0022] [Formula 2]

[0023] (Y1-X1)·(Z1-X1)=Y1·Z1·0.85

[0024] In the above formula 2, Y1 is the horizontal length of the outermost cathode, and Z1 is the vertical length of the outermost cathode.

[0025] In addition, in the deactivation method of the outermost cathode, in the deactivation step, the width (w) is determined within the range of 1.0X2 to 1.5X2 when the ratio (A / B) is 1.2 or more, and the X2 can be calculated by the following equation 3:

[0026] [Formula 3]

[0027] (Y-X2)·(Z-X2)=Y2·Z2·0.8

[0028] In the above formula 3, Y2 is the horizontal length of the outermost cathode, and Z2 is the vertical length of the outermost cathode.

[0029] In addition, in the method for deactivating the outermost cathode, the deactivation region can be formed by attaching an insulating tape or coating an insulating material.

[0030] In addition, in the method for deactivating the outermost cathode, the insulating tape may have a polyimide layer formed on one or both sides.

[0031] Additionally, in the method for deactivating the outermost cathode, the insulating material may include an epoxy compound or aluminum oxide.

[0032]

[0033] According to another embodiment of the present invention, a method for manufacturing an electrode assembly is provided, comprising: an inactivation step of forming an inactivation region having a predetermined width (w) along one edge of a first cathode; a step of sequentially stacking a separator, a first cathode having an inactivation region formed thereon, a separator, and an anode to manufacture a first mono cell; a step of sequentially stacking a separator, a second cathode having no inactivation region formed thereon, a separator, and an anode to manufacture a plurality of second mono cells; a step of sequentially stacking a separator, a first cathode having an inactivation region formed thereon, and a separator to manufacture a half cell; a step of sequentially stacking a plurality of second mono cells on the first mono cell to manufacture a laminate; and a step of sequentially stacking the half cell on the second mono cell arranged at the uppermost end of the laminate to manufacture an electrode assembly, wherein in the inactivation step, the width (w) is determined based on a horizontal length of the first cathode, a vertical length of the first cathode, and the numbers of first and second mono cells in the electrode assembly.

[0034] In addition, in the method for manufacturing the electrode assembly, in the deactivation step, the width (w) is determined within a range of 0.9P2 to 1.2P2, and the P2 can be calculated by the following equation 4:

[0035] [Formula 4]

[0036]

[0037] In the above formula 4, a2 is the horizontal length of the first cathode, b2 is the vertical length of the first cathode, and c2 is the number of the first and second mono cells.

[0038] In addition, in the method for manufacturing the electrode assembly, the width (w) in the deactivation step can be determined based on the ratio (A / B) of the sum of the areas (A) of the faces of the plurality of cathodes in the electrode assembly and the sum of the areas (B) of the faces of the plurality of anodes.

[0039] In addition, in the method for manufacturing the electrode assembly, in the deactivation step, the width (w) is determined within a range of 1.0X3 to 1.25X3 when the ratio (A / B) is 1.1 or more and less than 1.2, and the X3 can be calculated by the following equation 5:

[0040] [Formula 5]

[0041] (Y2-X3)·(Z2-X3)=Y2·Z2·0.85

[0042] In the above formula 5, Y2 is the horizontal length of the first cathode, and Z2 is the vertical length of the first cathode.

[0043] In addition, in the method for manufacturing the electrode assembly, in the deactivation step, the width (w) is determined to be within the range of 1.0X4 to 1.5X4 when the ratio (A / B) is 1.2 or more, and the X4 can be calculated by the following equation 6:

[0044] [Formula 6]

[0045] (Y2-X4)·(Z2-X4)=Y2·Z2·0.8

[0046] In the above formula 4, Y2 is the horizontal length of the first cathode, and Z2 is the vertical length of the first cathode.

[0047] In addition, in the method for manufacturing the electrode assembly, a judgment step may be included to determine whether deactivation of the first cathode in the first mono cell and the half cell is necessary based on the number of first and second mono cells before the deactivation step.

[0048] Additionally, in the method for manufacturing the electrode assembly, the determination step may determine that deactivation of the first cathode in the first mono cell and the half cell is necessary when the number of the first and second mono cells is less than a predetermined value.

[0049] Additionally, in the method for manufacturing the electrode assembly, the determination step may determine that deactivation of the first cathode in the first mono cell and the half cell is necessary when the number of the first and second mono cells is less than 15.

[0050] In addition, the method for manufacturing the electrode assembly may include a judgment step for judging whether deactivation of the first cathode in the first mono cell and the half cell is necessary based on the ratio (A / B) before the deactivation step.

[0051] In addition, in the method for manufacturing the electrode assembly, the judgment step can determine that deactivation of the first cathode in the first mono cell and half cell is necessary if the ratio (A / B) is 1.1 or more.

[0052]

[0053] According to another embodiment of the present invention, an electrode assembly is provided, comprising: a first mono cell in which a separator, a first cathode in which an inactive region having a predetermined width (w) formed along one edge thereof, a separator, and an anode are sequentially stacked; a plurality of second mono cells stacked on the first mono cell in which a separator, a second cathode, a separator, and an anode are sequentially stacked; and a half cell stacked on the second mono cell arranged at the top in which a separator, a first cathode in which an inactive region is formed, and a separator are sequentially stacked, wherein the width (w) of the inactive region is in the range of 0.9P2 to 1.2P2, and the P2 is calculated by the following equation 4:

[0054] [Formula 4]

[0055]

[0056] In the above formula 4, a2 is the horizontal length of the first cathode, b2 is the vertical length of the first cathode, and c2 is the number of the first and second mono cells.

[0057]

[0058] According to another embodiment of the present invention, there is provided a first mono cell comprising a separator, a first cathode having an inactive region having a predetermined width (w) formed along one edge thereof, a separator, and an anode sequentially stacked; a plurality of second mono cells stacked on the first mono cell, each comprising a separator, a second cathode, a separator, and an anode sequentially stacked; And an electrode assembly is provided, which comprises a first cathode having a separator, an inactive region formed thereon, and a half-cell in which the separator is sequentially stacked on a second monocell disposed at the top, and wherein the ratio (A / B) of the sum of the areas (A) of the surfaces of the plurality of cathodes in the electrode assembly to the sum of the areas (B) of the surfaces of the plurality of anodes is 1.1 or more and less than 1.2, and the width (w) of the inactive region is within the range of 1.0X3 to 1.25X3, and the ratio (A / B) of the sum of the areas (A) of the surfaces of the plurality of cathodes in the electrode assembly to the sum of the areas (B) of the surfaces of the plurality of anodes is 1.2 or more, and the width (w) of the inactive region is within the range of 1.0X4 to 1.5X4, and wherein X3 and X4 are calculated by the following equations 5 and 6, respectively:

[0059] [Formula 5]

[0060] (Y2-X3)·(Z2-X3)=Y2·Z2·0.85

[0061] [Formula 6]

[0062] (Y2-X4)·(Z2-X4)=Y2·Z2·0.8

[0063] In the above formulas 5 and 6, Y2 is the horizontal length of the first cathode, and Z2 is the vertical length of the first cathode.

[0064] The present invention can provide a clear guide for the deactivation operation of the outermost cathode of an electrode assembly.

[0065] FIG. 1 is a drawing showing a laminated structure of an electrode assembly according to one embodiment of the present invention.

[0066] Figure 2 is a drawing showing the inactive region of the outermost cathode.

[0067] Figure 3 is a drawing showing a mono cell and a half cell including a double-sided electrode with two single-sided electrodes joined together.

[0068] Figure 4 is a drawing for explaining local reactions and main reactions within an electrode assembly during an activation process.

[0069] Hereinafter, a method for deactivating the outermost cathode according to an embodiment of the present invention will be described in detail with reference to the attached drawings.

[0070] FIG. 1 is a drawing showing a laminated structure of an electrode assembly according to one embodiment of the present invention, FIG. 2 is a drawing showing an inactive region of the outermost cathode, and FIG. 3 is a drawing showing a mono-cell and a half-cell including a double-sided electrode in which two single-sided electrodes are joined.

[0071] The present invention relates to a method for deactivating a pair of outermost cathodes (102-1) each disposed at the uppermost and lowermost ends of an electrode assembly (100) including a plurality of anodes (103), a plurality of cathodes (102), and a plurality of separators (101).

[0072] The above method includes a deactivation step of forming an deactivation region (104) having a predetermined width (w) along one edge of the outermost cathode (102-1).

[0073] In the above deactivation step, the width (w) is determined based on the horizontal length of the outermost cathode (102-1), the vertical length of the outermost cathode (102-1), and the number of mono cells (110) composed of a separator (101), a cathode (102), a separator (101), and an anode (103) within the electrode assembly (100).

[0074] First, in the present invention, the electrode assembly (100) may include a mono cell (110) in which a separator (101), a cathode (102), a separator (101), and an anode (103) are sequentially stacked, and a half cell (130) in which a separator (101), a cathode (102), and a separator (101) are sequentially stacked.

[0075] The electrode assembly (100) may include a laminate (120) in which a plurality of mono cells (110) are laminated, and a half cell (130) laminated on the laminate (120).

[0076] The electrode assembly (100) may have the first mono cell (110-1) placed at the bottom and the half cell (130) placed at the top.

[0077] In order to distinguish between the mono cell positioned at the lowest level and other mono cells in the present invention, the mono cell positioned at the lowest level is called the first mono cell (110-1), and the other mono cells are called the second mono cell (110-2).

[0078] The first mono cell (110-1) and the second mono cell (110-2) are distinguished based on whether or not an inactive region is formed in the cathode. The first mono cell (110-1) may include a first cathode (102-1) in which an inactive region is formed, and the second mono cell (110-2) may include a second cathode (102-2) in which an inactive region is not formed.

[0079] In the present invention, the first cathode (102-1) in which the inactive region (104) is formed is the outermost cathode. Therefore, the drawing reference number of the first cathode will be '102-1', the same as that of the outermost cathode. In addition, in order to distinguish the outermost cathode from the remaining cathodes, the remaining cathodes will be referred to as the second cathode (102-2).

[0080] In the present invention, the outermost cathode (102-1) may refer to the cathode of the first mono cell (110-1) located at the lowest end of the laminate (120) and the cathode of the half cell (130).

[0081] Since the mono cell (110) and the half cell (130) are manufactured by laminating a separator on both sides of the cathode (102), the deactivation step can be performed before the cathode (102) and the separator (101) are laminated.

[0082] That is, in the present invention, the deactivation step can be performed before manufacturing the mono cell (110) and the half cell (130).

[0083] For example, the first mono cell (110-1) placed at the bottom and the half cell (130) placed at the top can be manufactured by laminating the outermost cathode (102-1) and the separator (101) in which an inactivation region is formed through a deactivation step according to the method of the present invention.

[0084] In the present invention, the anode (103) or cathode (102) has a rectangular surface formed by a pair of long sides and a pair of short sides. In the present invention, the horizontal length of the outermost cathode means the length of the long side, and the vertical length of the outermost cathode means the length of the short side.

[0085] In addition, in the present invention, one side of the electrode has a rectangular shape, and in the present invention, one side of the electrode is interpreted as excluding the electrode tab that is formed to protrude outside the cross-section of the rectangle.

[0086] Since the above width (w) is determined based on the horizontal length of the outermost electrode (102-1), the vertical length of the outermost cathode (102-1), and the number of mono cells (110) composed of a separator (101), a cathode (102), a separator (101), and an anode (103) within the electrode assembly (100), it is possible to secure a minimum inactive area that does not deteriorate battery performance, and thus it is expected that the manufacturing cost consumed in forming the inactive area will be reduced.

[0087] In one example, in the deactivation step, the width (w) is determined within a range of 0.9P1 to 1.2P1, and the P1 can be calculated by the following equation 1:

[0088] [Formula 1]

[0089]

[0090] In the above formula 1, a1 is the horizontal length of the outermost cathode (102-1), b1 is the vertical length of the outermost cathode (102-1), and c1 is the number of mono cells (110) composed of a separator (101), a cathode (102), a separator (101), and an anode (103) in the electrode assembly (100).

[0091] In the above formula 1, c1 can be a natural number less than 15, for example, a natural number from 2 to 14.

[0092] The number of mono cells (110) can be determined in advance before manufacturing the electrode assembly (100), and therefore, the width of the deactivation region can be adjusted by considering the c1 value in the deactivation step performed before manufacturing the mono cell (110) and the half cell (130).

[0093] For example, when manufacturing an electrode assembly (100) having 14 mono cells (110), the width of the deactivation region can be adjusted using the p value calculated by substituting 14 for c in the above formula 1 in the deactivation step.

[0094] Additionally, the unit of the width of the above-described inactive area (104) may be mm or cm.

[0095] Since the electrode assembly (100) includes a plurality of mono cells (110) and one half cell (130), the number of cathodes (102) and anodes (103) may be different from each other, for example, the number of cathodes (102) may be one more than the number of anodes (103).

[0096] An electrode assembly (100) comprising two mono cells (110) and one half cell (130) may include two positive electrodes (103) and three negative electrodes (102).

[0097] In one example, the inactive region (104) may be formed on one side of the cathode that is in contact with the outermost separator.

[0098] Specifically, the first mono cell (110-1) located at the bottom may be formed by sequentially stacking a first separator (101-1), an outermost cathode (102-1), a second separator (101-2), and an anode (103), and an inactive region (104) may be formed on one surface (102-1a) of the outermost cathode (102-1) facing the first separator (101-1).

[0099] In addition, the half-cell (130) located at the top may be formed by sequentially stacking a third separator (101-3), an outermost cathode (102-1), and a fourth separator (101-4), and an inactive region (104) may be formed on one side (102-1a) of the outermost cathode (102-1) facing the fourth separator (101-4).

[0100] Figure 3 is a drawing showing a mono cell and a half cell including a double-sided electrode with two single-sided electrodes joined together.

[0101] Referring to FIG. 3, the anode may be a double-sided anode in which two single-sided anodes are joined, and the cathode may be a double-sided cathode in which two single-sided cathodes are joined.

[0102] For example, an electrode assembly (100) comprising two mono cells (110) and one half cell (130) may comprise two double-sided positive electrodes and three double-sided negative electrodes, and may comprise four single-sided positive electrodes and six single-sided negative electrodes.

[0103] Meanwhile, in the case of a double-sided cathode in which two single-sided cathodes are joined, the inactive region (104) can be formed on one side of the single-sided cathode located relatively at the outermost side.

[0104] For example, as shown in (a) of FIG. 3, the half-cell (130) located at the top may have a third separator (101-3), a third cross-sectional cathode (102a), a fourth cross-sectional cathode (102b), and a fourth separator (101-4) sequentially laminated, and an inactive region (104) may be formed on one surface of the second cross-sectional cathode (102b) facing the fourth separator (101-4).

[0105] In addition, as shown in (b) of FIG. 3, the first mono cell (110-1) located at the bottom is sequentially laminated with a first separator (101-1), a first cross-sectional cathode (102a), a second cross-sectional cathode (102b), a second separator (101-2), a first cross-sectional anode (103a), and a second cross-sectional anode (103b), and the inactive region (104) can be formed on one surface of the first cross-sectional cathode (102a) facing the first separator (101).

[0106] Additionally, to prevent NP ratio (ratio of cathode capacity to cathode capacity per unit area) reversal and lithium plating, the area of ​​the cathode (102) may be larger than the area of ​​the cathode (103).

[0107] In one example, in the deactivation step, the width (w) can be determined based on the ratio (A / B) of the sum of the areas (A) of the faces of the plurality of cathodes (102) in the electrode assembly (100) and the sum of the areas (B) of the faces of the plurality of anodes (103).

[0108] Since the above width (w) is determined based on the above ratio (A / B), a minimum inactive area that does not deteriorate battery performance can be secured, and thus a reduction in manufacturing costs consumed in forming the inactive area can be expected.

[0109] Specifically, the above ratio (A / B) may decrease as the number of mono cells in the electrode assembly (e.g., the sum of the numbers of the first and second mono cells) increases, and may decrease as the area of ​​one side of the positive electrode and the area of ​​one side of the negative electrode increase.

[0110] Below, Tables 1 to 3 exemplarily show the increase in the number of mono cells in the electrode assembly and the ratio (A / B) according to the area of ​​one side of the positive electrode and one side of the negative electrode.

[0111] Here, the area of ​​one side of the positive electrode can be calculated by multiplying the horizontal length of the positive electrode by the vertical length of the positive electrode, and the area of ​​one side of the negative electrode can be calculated by multiplying the horizontal length of the negative electrode by the vertical length of the negative electrode.

[0112] In addition, the sum of the areas of the faces of multiple cathodes (A) can be calculated by multiplying the area of ​​one face of the cathodes by the number of cathodes, and the sum of the areas of one face of multiple anodes (B) can be calculated by multiplying the area of ​​one face of the anodes by the number of anodes.

[0113] In addition, the electrode assemblies of Tables 1 and 3 were manufactured by stacking two mono cells and one half cell, and at this time, the number of positive electrodes is two and the number of negative electrodes is three.

[0114] In addition, the electrode assembly of Table 2 was manufactured by stacking four mono cells and one half cell, and at this time, the number of positive electrodes is four and the number of negative electrodes is five.

[0115] Below, in Tables 1 to 3, the ‘number of mono cells in the electrode assembly’ is the sum of the numbers of the first mono cell (110-1) and the second mono cell (110-2).

[0116] Anode width 3cm Anode length 4cm Cathode width 3.1cm Cathode length 4.1cm Area of ​​one side of the anode 12cm 2 Number of anodes: 2 Area of ​​one side of cathode: 12.71 cm 2 Number of cathodes3Number of mono cells in the electrode assembly2Ratio (A / B)1.59

[0117] Anode width 3cm Anode length 4cm Cathode width 3.1cm Cathode length 4.1cm Area of ​​one side of the anode 12cm 2 Number of anodes: 4 Area of ​​one side of cathode: 12.71 cm 2 Number of cathodes 5 Number of mono cells in the electrode assembly 4 Ratio (A / B) 1.32

[0118] Anode width 8cm Anode length 20cm Cathode width 8.1cm Cathode length 20.1cm Area of ​​one side of the anode 160cm 2 Number of anodes2 Area of ​​one side of cathode162.81cm 2 Number of cathodes3Number of mono cells in the electrode assembly2Ratio (A / B)1.53

[0119] Referring to Tables 1 and 2 above, it was confirmed that the ratio (A / B) decreased from 1.59 to 1.32 when the number of mono cells in the electrode assembly increased from 2 to 4.

[0120] Also, referring to Tables 1 and 3, the anode area is 12cm 2 160cm at 2 , and the cathode area is 12.71cm 2 162.81cm at 2 As it increased, it was confirmed that the ratio (A / B) decreased from 1.59 to 1.53.

[0121] From the above Tables 1 to 3, it can be confirmed that the ratio (A / B) decreases as the number of mono cells in the electrode assembly increases, and decreases as the area of ​​one side of the positive electrode and the area of ​​one side of the negative electrode increase.

[0122] Additionally, as the number of mono cells in the electrode assembly increases, the ratio of electrodes participating in the main reaction increases, which may result in a decrease in the ratio of local reactions to the main reaction.

[0123] Similarly, as the area of ​​one side of the anode or cathode increases, the proportion of electrodes participating in the main reaction increases, which may lower the ratio of local reactions to the main reaction. When the ratio of local reactions decreases to a negligible level, deactivation may not be necessary.

[0124] Therefore, the above ratio (A / B) can be used as an index for quantitatively analyzing the local reaction ratio, as it is linked to the number of mono cells in the electrode assembly and the area of ​​one side of the electrode, which affect the local reaction ratio.

[0125] The present invention can quantitatively analyze whether the local reaction ratio is negligible or not through the ratio (A / B), and based on this, can form an inactivation area with an optimal size that can minimize the use of unnecessary inactivation material.

[0126] In one example, in the deactivation step, the width (w) is determined within a range of 1.0X1 to 1.25X1 when the ratio (A / B) is 1.1 or more and less than 1.2, and the X1 can be calculated by the following equation 2:

[0127] [Formula 2]

[0128] (Y1-X1)·(Z1-X1)=Y1·Z1·0.85

[0129] In the above formula 2, Y1 is the horizontal length of the outermost cathode (102-1), and Z1 is the vertical length of the outermost cathode (102-1).

[0130] In another example, in the deactivation step, the width (w) is determined within the range of 1.0X2 to 1.5X2 when the ratio (A / B) is 1.2 or more, and the X2 can be calculated by the following equation 3:

[0131] [Formula 3]

[0132] (Y-X2)·(Z-X2)=Y2·Z2·0.8

[0133] In the above formula 3, Y2 is the horizontal length of the outermost cathode (102-1), and Z2 is the vertical length of the outermost cathode (102-1).

[0134] In the above formulas 3 and 4, the units of the horizontal length of the outermost cathode (102-1) and the vertical length of the outermost cathode (102-1) may be mm or cm.

[0135] As the above width (w) is determined differently based on the above ratio (A / B), the size of the optimal deactivation area (104) in which the local reaction can be ignored compared to the main reaction can be provided, thereby minimizing the use of unnecessary deactivation material.

[0136] In one example, the inactive area (104) can be formed by attaching an insulating tape or coating an insulating material.

[0137] The coating of the above insulating material can be performed using various known coating methods without limitation, such as spray coating and die coating.

[0138] The above insulating tape may have a polyimide layer formed on one or both sides. The insulating tape having the polyimide layer formed on one or both sides has excellent adhesive and insulating properties and can exhibit an excellent effect in deactivating the outermost cathode (102-1).

[0139] The insulating material may include an epoxy compound or aluminum oxide.

[0140]

[0141] The present invention also relates to a method for manufacturing an electrode assembly. This method is a method for manufacturing an electrode assembly in conjunction with the aforementioned method for deactivating the outermost cathode. Accordingly, any detailed descriptions that overlap with the aforementioned content will be omitted below.

[0142] Referring to the drawings, the manufacturing method includes: an inactivation step of forming an inactivation region (104) having a predetermined width (w) along one edge of a first cathode (102-1); a step of sequentially stacking a separator (101), a first cathode (102-1) in which an inactivation region (104) is formed, a separator (101), and an anode (103) to manufacture a first mono cell (110-1); a step of sequentially stacking a separator (101), a second cathode (102-2) in which an inactivation region is not formed, a separator (101), and an anode (103) to manufacture a plurality of second mono cells (110-2); a step of sequentially stacking a separator (101), a first cathode (102-1) in which an inactivation region is formed, and a separator (101) to manufacture a half cell (130); A step of manufacturing a laminate (120) by stacking a plurality of second mono cells (110-2) on a first mono cell (110-1); and a step of manufacturing an electrode assembly (100) by stacking a half cell (130) on the second mono cell (110-2) arranged at the top of the laminate (120), wherein in the deactivation step, the width (w) is determined based on the horizontal length of the first cathode (102-1), the vertical length of the first cathode (102-1), and the number of the first and second mono cells (110-1, 110-2).

[0143] In one example, in the deactivation step, the width (w) is determined within a range of 0.9P2 to 1.2P2, and the P2 can be calculated by the following equation 4:

[0144] [Formula 4]

[0145]

[0146] In the above formula 4, a2 is the horizontal length of the first cathode, b2 is the vertical length of the first cathode, and c2 is the number of the first and second mono cells.

[0147] Additionally, in the deactivation step, the width (w) can be determined based on the ratio (A / B) of the sum of the areas (A) of the faces of the plurality of cathodes (102) in the electrode assembly (100) and the sum of the areas (B) of the faces of the plurality of anodes (103).

[0148] In one example, in the deactivation step, the width (w) is determined within a range of 1.0X3 to 1.25X3 when the ratio (A / B) is 1.1 or more and less than 1.2, and the X3 can be calculated by the following formula 5:

[0149] [Formula 5]

[0150] (Y2-X3)·(Z2-X3)=Y2·Z2·0.85

[0151] In the above formula 5, Y2 is the horizontal length of the first cathode (102-1), and Z2 is the vertical length of the first cathode (102-1).

[0152] In another example, in the deactivation step, the width (w) is determined within the range of 1.0X4 to 1.5X4 when the ratio (A / B) is 1.2 or more, and the X4 can be calculated by the following equation 6:

[0153] [Formula 6]

[0154] (Y2-X4)·(Z2-X4)=Y2·Z2·0.8

[0155] In the above formula 6, Y2 is the horizontal length of the first cathode (102-1), and Z2 is the vertical length of the first cathode (102-1).

[0156] In the above formulas 5 and 6, the units of the horizontal length of the first cathode (102-1) and the vertical length of the first cathode (102-1) may be mm or cm.

[0157] In one specific example, before the deactivation step, a judgment step may be included to determine whether deactivation of the first mono cell (110-1) and the first cathode (102-1) in the half cell (130) is necessary based on the number of first and second mono cells (110-1, 110-2).

[0158] The method according to the present invention determines, from the judgment step, that deactivation of the electrode assembly (100) is necessary, the width (w) of the deactivation region (104) in the deactivation step based on the horizontal length of the first cathode (102-1), the vertical length of the first cathode (102-1), and the number of the first and second mono cells (110-1, 110-2), thereby minimizing the use of unnecessary materials in the deactivation region while reducing resistance due to local reaction, thereby preventing degradation of the battery (lithium secondary battery) performance, which will be described in detail later.

[0159] The above judgment step may determine that deactivation of the first cathode (102-1) in the first mono cell (110-1) and the half cell (130) is necessary when the number of the first and second mono cells (110-1, 110-2) is less than a predetermined value.

[0160] Specifically, the above judgment step may determine that deactivation of the first cathode (102-1) in the first mono cell (110-1) and the half cell (130) is necessary when the number of the first and second mono cells (110-1, 110-2) is less than 15.

[0161] That is, when the sum of the numbers of the first and second mono cells (110-1, 110-2) is within the range of 2 to 14, the judgment step may determine that deactivation of the first cathode (102-1) in the first mono cell (110-1) and the half cell (130) is necessary.

[0162] In other words, the deactivation step according to the method of the present invention can be performed when manufacturing an electrode assembly in which the sum of the numbers of the first and second mono cells (110-1, 110-2) is less than 15, for example, within the range of 2 to 14.

[0163] Figure 4 is a drawing for explaining local reactions and main reactions within an electrode assembly during an activation process.

[0164] Referring to Fig. 4, during the activation process, the first cathode (102-1) reacts with an adjacent electrode, causing a local reaction that is involved in charge / discharge. Furthermore, a charge / discharge reaction (main reaction) occurs between the electrodes, separator, and electrolyte within the remaining mono cell (110), excluding the first cathode (102-1), as lithium moves.

[0165] In particular, when the number of mono cells (110) in the electrode assembly (100) is less than 15, the ratio of local reactions to the main reactions increases to a certain degree or more. Accordingly, unnecessary electrolyte consumption and unevenness of the electrode assembly may occur, and the resistance value in the secondary battery may increase, resulting in a problem of lowering the output of the secondary battery.

[0166] In order to solve the above problem, the above judgment step may determine that deactivation of the first cathode (102-1) in the first mono cell (110-1) and the half cell (130) is necessary when the number of the first and second mono cells (110-1, 110-2) is less than 15, and perform the deactivation step.

[0167] On the other hand, the above judgment step may determine that deactivation is unnecessary when the number of the first and second mono cells (110-1, 110-2) is 15 or more. When the number of the first and second mono cells (110-1, 110-2) is 15 or more, the ratio of local reactions to the main reactions is reduced to a certain level or less, so that the local reactions are negligible, and therefore, even if the deactivation operation is not performed, it may not be a major problem.

[0168] In terms of the main reaction and local reaction, the deactivation step determines the width (w) of the deactivation region (104) based on the horizontal length of the first cathode (102-1), the vertical length of the first cathode (102-1), and the number of the first and second mono cells (110-1, 110-2) according to the above formula 2, thereby providing an optimal size of the deactivation region (104) in which the local reaction can be ignored compared to the main reaction, thereby minimizing the material consumption of the unnecessary deactivation region (104).

[0169] In addition, the method according to the present invention may include a judgment step for judging whether deactivation of the first cathode (102-1) in the first mono cell (110-1) and the half cell (130) is necessary based on the ratio (A / B) before the deactivation step.

[0170] The above deactivation step may form a deactivation area (104) if deactivation is determined to be necessary in the above judgment step.

[0171] The above judgment step can determine that deactivation of the first cathode (102-1) in the first mono cell (110-1) and the half cell (130) is necessary if the ratio (A / B) is 1.1 or more.

[0172] The method according to the present invention determines the width (w) of the deactivation region (104) based on the ratio (A / B) in the deactivation step when it is determined from the judgment step that deactivation of the electrode assembly (100) is necessary, thereby minimizing the use of unnecessary materials in the deactivation region while reducing resistance due to local reaction, thereby preventing degradation of the battery (lithium secondary battery) performance.

[0173] Referring to Fig. 4, during the activation process, the first cathode (102-1) reacts with an adjacent electrode, causing a local reaction that is involved in charge / discharge. Furthermore, a charge / discharge reaction (main reaction) occurs between the electrodes, separator, and electrolyte within the remaining mono cell (110), excluding the first cathode (102-1), as lithium moves.

[0174] In particular, when the above ratio (A / B) is 1.1 or higher, the ratio of local reactions to the main reaction increases to a certain degree. Accordingly, unnecessary electrolyte consumption and unevenness of the electrode assembly may occur, and the resistance value within the secondary battery may increase, resulting in a decrease in the output of the secondary battery.

[0175] In order to solve the above problem, the above judgment step can determine that deactivation of the first cathode (102-1) is necessary when the ratio (A / B) is 1.1 or more, and perform the deactivation step.

[0176] On the other hand, the above judgment step may determine that deactivation is unnecessary when the ratio (A / B) is less than 1.1. If the ratio (A / B) is less than 1.1, the ratio of local reactions to the main reaction is reduced to a certain level, so that the local reactions are negligible, and therefore, even if the deactivation operation is not performed, there may not be a major problem.

[0177] In terms of the main reaction and local reaction, the deactivation step can minimize material consumption of unnecessary deactivation regions (104) by providing an optimal size of the deactivation region (104) in which the local reaction can be ignored compared to the main reaction by differently determining the width (w) of the deactivation region (104) based on the ratio (A / B) according to the above equations 5 and 6.

[0178]

[0179] The present invention also relates to an electrode assembly. The electrode assembly may be manufactured by the method described above.

[0180] The above electrode assembly (100) includes a plurality of positive electrodes (103), a plurality of negative electrodes (102), and a plurality of separators (101), and includes a pair of outermost negative electrodes (102-1) arranged at the uppermost and lowermost ends, respectively.

[0181] Specifically, the electrode assembly (100) comprises: a first mono cell (110-1) in which a separator (101), a first cathode (102-1) in which an inactive region (104) having a predetermined width (w) is formed along one edge thereof, a separator (101), and an anode (103) are sequentially stacked; a plurality of second mono cells (110-2) stacked on the first mono cell (110-1) in which a separator (101), a second cathode (102-2), a separator (101), and an anode (103) are sequentially stacked; And it is stacked on the second monocell (110-2) arranged at the top, and includes a separator (101), a first cathode (102-1) in which an inactive region is formed, and a half-cell (130) in which a separator (101) is sequentially stacked, and the width (w) of the inactive region (104) is within the range of 0.9P2 to 1.2P2, and the P2 can be calculated by the following equation 4:

[0182] [Formula 4]

[0183]

[0184] In the above formula 4, a2 is the horizontal length of the first cathode, b2 is the vertical length of the first cathode, and c2 is the number of the first and second mono cells.

[0185] In one example, the number of the first and second mono cells (110-1, 110-2) may be less than 15.

[0186] As explained above, when the number of the first and second mono cells (110-1, 110-2) is less than 15, a problem due to local reaction may occur, so a deactivation region (104) must be formed. At this time, the width (w) of the deactivation region (104) is determined according to Equation 2, so that the use of unnecessary materials for the deactivation region can be minimized while preventing problems due to local reaction.

[0187] In one example, the inactive region (104) may include an insulating tape attached along one edge of the first cathode (102-1), or an insulating material coated along the edge of the first cathode (102-1).

[0188] The coating of the above insulating material can be performed using various known coating methods without limitation, such as spray coating and die coating.

[0189] The above insulating tape may have a polyimide layer formed on one or both sides. The insulating tape having the polyimide layer formed on one or both sides has excellent adhesive and insulating properties and can exhibit an excellent effect in deactivating the first cathode (102-1).

[0190] The insulating material may include an epoxy compound or aluminum oxide.

[0191]

[0192] The present invention also relates to an electrode assembly. The electrode assembly may be manufactured by the method described above.

[0193] The above electrode assembly (100) includes a plurality of positive electrodes (103), a plurality of negative electrodes (102), and a plurality of separators (101), and includes a pair of outermost negative electrodes (102-1) arranged at the uppermost and lowermost ends, respectively.

[0194] Specifically, the electrode assembly (100) includes a first mono cell (110-1) in which a separator (101), a first cathode (102-1) in which an inactive region (104) having a predetermined width (w) is formed along one edge thereof, a separator (101), and an anode (103) are sequentially stacked; a plurality of second mono cells (110-2) stacked on the first mono cell (110-1) in which a separator (101), a second cathode (102-2), a separator (101), and an anode (103) are sequentially stacked; and a half cell (130) stacked on the second mono cell (110-2) arranged at the top in which a separator (101), a first cathode (102-1) in which an inactive region is formed, and a separator (101) are sequentially stacked.

[0195] When the ratio (A / B) of the sum of the areas (A) of the surfaces of the plurality of cathodes (102) in the electrode assembly and the sum of the areas (B) of the surfaces of the plurality of anodes (103) is 1.1 or more and less than 1.2, the width (w) of the deactivation region (104) is within the range of 1.0X3 to 1.25X3.

[0196] And, the ratio (A / B) of the sum of the areas (A) of the faces of the plurality of cathodes (102) in the electrode assembly and the sum of the areas (B) of the faces of the plurality of anodes (103) is 1.2 or more, and the width (w) of the inactive region is within the range of 1.0X4 to 1.5X4.

[0197] The above X3 and X4 are calculated by the following formulas 5 and 6, respectively:

[0198] [Formula 5]

[0199] (Y2-X3)·(Z2-X3)=Y2·Z2·0.85

[0200] [Formula 6]

[0201] (Y2-X4)·(Z2-X4)=Y2·Z2·0.8

[0202] In the above formulas 5 and 6, Y2 is the horizontal length of the first cathode, and Z2 is the vertical length of the first cathode.

[0203] An electrode assembly (100) satisfying the above conditions has an optimal size of the deactivation region (104) in which the local reaction can be ignored compared to the main reaction.

[0204] In one example, the inactive area (104) can be formed by attaching an insulating tape or coating an insulating material.

[0205] The coating of the above insulating material can be performed using various known coating methods without limitation, such as spray coating and die coating.

[0206] The above insulating tape may have a polyimide layer formed on one or both sides. The insulating tape having the polyimide layer formed on one or both sides has excellent adhesive and insulating properties and can exhibit an excellent effect in deactivating the first cathode (102-1).

[0207] The insulating material may include an epoxy compound or aluminum oxide.

[0208]

[0209] The present application is specifically described through the following examples, but the scope of the present application is not limited by the following examples.

[0210]

[0211] Manufacturing example

[0212] Cathode manufacturing

[0213] A negative electrode slurry was prepared by mixing artificial graphite, conductive agent, and binder in a ratio of 94:3:3, and then applied to a copper current collector, dried, and rolled in sequence to produce a negative electrode.

[0214]

[0215] anode manufacturing

[0216] NCM811: Carbon black: PVDF were mixed in a ratio of 90:5:5 to prepare a cathode slurry, which was then applied to an aluminum current collector, dried, and rolled in sequence to produce a cathode.

[0217]

[0218] membrane

[0219] A polyethylene porous membrane was prepared.

[0220]

[0221] electrolyte

[0222] An electrolyte was prepared by dissolving 1M LiPF6 in a mixed solvent containing ethylene carbonate (EC), dimethyl carbonate (DMC), and ethylmethyl carbonate (EMC) in a volume ratio of 3:4:3.

[0223]

[0224] Example 1A

[0225] electrode assembly

[0226] Manufacturing Example The manufactured positive and negative electrodes were cut into 5×7 cm and 5.1×7.1 cm pieces, respectively.

[0227] Then, an outermost electrode was manufactured by forming an inactive region by applying insulating tape with a width of 0.5 cm along the edge of the cathode.

[0228] A laminate including a total of five mono cells was manufactured by stacking one first mono cell in which a separator, an outermost cathode (inactive area O), a separator, and an anode were sequentially stacked, and four second mono cells in which a separator, a cathode (inactive area X), a separator, and an anode were sequentially stacked.

[0229] Then, an electrode assembly was manufactured by stacking a half cell in which a separator, a cathode, and a separator were sequentially stacked on a mono cell located at the top of the laminate.

[0230] The electrode assembly manufactured according to Example 1A included five positive electrodes and six negative electrodes.

[0231] In addition, according to the specifications of the electrode assembly manufactured in Example 1A, the P1 value calculated by substituting 5.1 into a1 of Equation 1, 7.1 into b1, and 5 into c1 was 0.424.

[0232] When the P1 value is 0.424, the range of 0.9 P1 to 1.2 P1 is calculated to be 0.382 mm to 0.509 mm, so it was confirmed that the width of the inactive region of the electrode assembly manufactured in Example 1A, which is 0.5 cm, is within the range of 0.9 P1 to 1.2 P1.

[0233]

[0234] lithium secondary battery

[0235] After placing the above-manufactured electrode assembly inside a pouch case, the electrolyte manufactured above was injected into the case.

[0236] Then, after pre-aging for 2 days at room temperature, the battery was charged at a charging rate of 0.1C until the SOC reached 30%, aged for 1 day each at room temperature and 60°C, and then a degassing process was performed to discharge the gas inside the case, thereby manufacturing a lithium secondary battery.

[0237]

[0238] Example 2A

[0239] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 1, except that an outermost electrode was manufactured by forming an inactive region by processing an insulating tape with a width of 0.35 cm along the edge of the cathode, and a laminate having a total of 10 mono cells was manufactured by stacking one first mono cell and nine second mono cells.

[0240] The electrode assembly manufactured according to Example 2A included 10 positive electrodes and 11 negative electrodes.

[0241] In addition, according to the specifications of the electrode assembly manufactured in Example 2A, the P1 value calculated by substituting 5.1 into a1 of Equation 1, 7.1 into b1, and 10 into c1 was 0.297.

[0242] When the P1 value is 0.297, the range of 0.9P1 to 1.2P1 is calculated to be 0.267 mm to 0.357 mm, so it was confirmed that the width of the inactive region of the electrode assembly manufactured in Example 2A, which was 0.35 cm, was within the range of 0.9P1 to 1.2P1.

[0243]

[0244] Comparative Example 1A

[0245] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 1A, except that a laminate including a total of five mono cells was manufactured by stacking five second mono cells without the first mono cell.

[0246]

[0247] Comparative Example 2A

[0248] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 2A, except that a laminate including a total of 10 mono cells was manufactured by stacking 10 second mono cells without the first mono cell.

[0249]

[0250] Comparative Example 3A

[0251] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 2A, except that a first mono cell including a first negative electrode in which an inactive region was formed by treating an insulating tape with a width of 0.15 cm along the edge of the negative electrode was manufactured.

[0252]

[0253] According to the specifications of the electrode assembly manufactured in Comparative Example 3A, the P1 value calculated by substituting 5.1 for a1, 7.1 for b1, and 10 for c1 in Equation 1 was 0.297.

[0254] When the P1 value is 0.297, the range of 0.9P1 to 1.2P1 is calculated to be 0.267 mm to 0.357 mm, so it was confirmed that the width of 0.15 cm of the inactive region of the electrode assembly manufactured in Comparative Example 3A was outside the range of 0.9P1 to 1.2P1.

[0255]

[0256] Comparative Example 4A

[0257] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 1A, except that a laminate including a total of 15 mono cells was manufactured by stacking 15 second mono cells without the first mono cell.

[0258] For reference, the electrode assembly manufactured according to Comparative Example 4A contained 15 positive electrodes and 16 negative electrodes.

[0259]

[0260] Comparative Example 5A

[0261] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 1A, except that an outermost electrode was manufactured by forming an inactive region by processing an insulating tape with a width of 0.18 mm along the edge of the cathode, and a laminate including a total of 15 mono cells was manufactured by stacking one first mono cell and 14 second mono cells.

[0262]

[0263] Experimental Example 1

[0264] The lithium secondary batteries manufactured in Example 1A, Example 2A, and Comparative Examples 1A to 5A were measured for 10-second discharge resistance at SOC50, and the results are shown in Table 4 below.

[0265] Resistance (2.5C@SOC50, Ω) Number of first mono cells Number of second mono cells Total number of mono cells in the electrode assembly Example 1A 0.124 145 Example 2A 0.06 119 10 Comparative Example 1A 0.136-55 Comparative Example 2A 0.064-10 10 Comparative Example 3A 0.064 19 10 Comparative Example 4A 0.038-15 15 Comparative Example 5A 0.038 114 15

[0266] From the above experimental results, it was confirmed that the lithium secondary batteries manufactured in Examples 1A and 2A had a reduced resistance compared to Comparative Examples 1A and 2A. In addition, in the case of Comparative Example 3A, when converted to the P1 value calculated according to Equation 1, the width of the inactive region (0.15 mm) did not satisfy the range of 0.9P1 to 1.2P1, and it showed the same resistance value as Comparative Example 2A, which did not form the inactive region, so it was confirmed that the effect of the inactive region did not appear.

[0267] And, from Comparative Examples 4A and 5A, it was confirmed that when the sum of the numbers of the first and second mono cells in the electrode assembly is 15 or more, similar resistance values ​​are shown regardless of whether or not it is deactivated, and from this, it was found that when the sum of the numbers of the first and second mono cells is 15 or more, it is unnecessary to form a deactivation region.

[0268]

[0269] Experimental Example 2

[0270] For a 900mA small pouch secondary battery, the resistance value of the electrode assembly according to the ratio (A / B) was measured. The resistance was measured at 10 seconds with a 2.5C discharge pulse, and the results are shown in Table 5 below.

[0271] Ratio (A / B) Resistance (Ω) Example 1 B1.26 0.074 Example 2 B1.20.07 Comparative Example 1 B1.26 0.087 Comparative Example 2 B1.20.083

[0272] In the above Examples 1B and 2B, an imide tape having a width within the range of 1.0X4 to 1.5X4 according to the X4 value calculated from the above-described Equation 6 was attached to the edge of the outermost electrode to form an inactive region, while Comparative Examples 1B and 2B did not form an inactive region. Examples 1B and 2B showed lower resistance values ​​than Comparative Examples 1B and 2B. From this, it was confirmed that when the ratio (A / B) is 1.1 or higher, when the edge of the outermost electrode is inactive, the participation of the outermost electrode in the local reaction can be prevented.

[0273]

[0274] The preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art having ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims.

[0275]

[0276] Description of the symbol

[0277] 100: Electrode assembly

[0278] 101: Membrane

[0279] 102: Cathode

[0280] 103: Bipolar

[0281] 110: Monocell

[0282] 120: Laminate

[0283] 130: Half Cell

[0284] 102-1: Outermost cathode

[0285] 104: Disabled area

Claims

1. A method for deactivating a pair of outermost cathodes each disposed at the uppermost and lowermost ends of an electrode assembly including a plurality of anodes, a plurality of cathodes, and a plurality of separators, Including an inactivation step of forming an inactivation region having a predetermined width (w) along one edge of the outermost cathode, A method for deactivating an outermost cathode, wherein in the deactivation step, the width (w) is determined based on the horizontal length of the outermost cathode, the vertical length of the outermost cathode, and the number of mono cells composed of a separator, a cathode, a separator, and an anode in the electrode assembly.

2. In the first paragraph, the width (w) in the deactivation step is 0.9P. 1 1.2P inland 1 is determined within the range of P 1 The method of deactivating the outermost cathode is calculated by the following formula 1: [Formula 1] In the above formula 1, a 1 is the horizontal length of the outermost cathode, and b 1 is the vertical length of the outermost cathode, and c 1 is the number of mono cells consisting of a separator, cathode, separator, and anode within the electrode assembly.

3. A method for deactivating an outermost cathode in the first paragraph, wherein the width (w) in the deactivation step is determined based on a ratio (A / B) of the sum of the areas (A) of one side of a plurality of cathodes in the electrode assembly and the sum of the areas (B) of one side of a plurality of anodes.

4. In the third paragraph, in the deactivation step, the width (w) is 1.0X when the ratio (A / B) is 1.1 or more and less than 1.

2. 1 1.25X inland 1 Determined within the range, the above X 1 The deactivation method of the outermost cathode is calculated by the following formula 2: [Formula 2] (Y 1 -X 1 )·(Z 1 -X 1 )=Y 1 ·Z 1 ·0.85 In the above formula 2, Y 1 is the transverse length of the outermost cathode, and Z 1 is the vertical length of the outermost cathode.

5. In the third paragraph, in the deactivation step, the width (w) is 1.0X when the ratio (A / B) is 1.2 or more. 2 Inside 1.5X 2 Determined within the range, the above X 2 The method of deactivating the outermost cathode is calculated by the following formula 3: [Formula 3] (Y-X 2 )·(Z-X 2 )=Y 2 ·Z 2 ·0.8 In the above formula 3, Y 2 is the transverse length of the outermost cathode, and Z 2 is the vertical length of the outermost cathode.

6. A method for deactivating the outermost cathode in the first paragraph, wherein the deactivation region is formed by attaching an insulating tape or coating an insulating material.

7. A method for deactivating the outermost cathode in accordance with claim 6, wherein the insulating tape has a polyimide layer formed on one or both sides.

8. A method for deactivating the outermost cathode in accordance with claim 6, wherein the insulating material comprises an epoxy compound or aluminum oxide.

9. A deactivation step of forming a deactivation region having a predetermined width (w) along one edge of the first cathode; A step of manufacturing a first mono cell by sequentially laminating a first cathode, a separator, and an anode having a separator and an inactive region formed thereon; A step of manufacturing a plurality of second mono cells by sequentially stacking a separator, a second cathode in which an inactive region is not formed, a separator, and an anode; A step of manufacturing a half-cell by sequentially laminating a separator, a first cathode having an inactive region formed thereon, and a separator; A step of manufacturing a laminate by stacking a plurality of second mono cells on a first mono cell; and A step of manufacturing an electrode assembly by stacking a half cell on a second mono cell arranged at the top of the laminate, A method for manufacturing an electrode assembly, wherein in the deactivation step, the width (w) is determined based on the horizontal length of the first cathode, the vertical length of the first cathode, and the number of first and second mono cells in the electrode assembly.

10. In the 9th paragraph, the width (w) in the deactivation step is 0.9P. 2 1.2P inland 2 is determined within the scope of P, and 2 A method for manufacturing an electrode assembly, which is calculated by the following formula 4: [Formula 4] In the above formula 4, a 2 is the transverse length of the first cathode, and b 2 is the vertical length of the first cathode, and c 2 are the numbers of first and second mono cells.

11. A method for manufacturing an electrode assembly in the 9th paragraph, wherein in the deactivation step, the width (w) is determined based on the ratio (A / B) of the sum of the areas (A) of the faces of the plurality of cathodes in the electrode assembly and the sum of the areas (B) of the faces of the plurality of anodes.

12. In the 11th paragraph, in the deactivation step, the width (w) is 1.0X when the ratio (A / B) is 1.1 or more and less than 1.

2. 3 1.25X inland 3 Determined within the range, the above X 3 A method for manufacturing an electrode assembly, wherein the electrode assembly is calculated by the following formula 5: [Formula 5] (Y 2 -X 3 )·(Z 2 -X 3 )=Y 2 ·Z 2 ·0.85 In the above formula 5, Y 2 is the transverse length of the first cathode, and Z 2 is the vertical length of the first cathode.

13. In the 11th paragraph, in the deactivation step, the width (w) is 1.0X when the ratio (A / B) is 1.2 or more. 4 Inside 1.5X 4 Determined within the range, the above X 4 A method for manufacturing an electrode assembly, wherein the electrode assembly is calculated by the following formula 6: [Formula 6] (Y 2 -X 4 )·(Z 2 -X 4 )=Y 2 ·Z 2 ·0.8 In the above formula 4, Y 2 is the transverse length of the first cathode, and Z 2 is the vertical length of the first cathode.

14. A method for manufacturing an electrode assembly, comprising a judgment step of judging whether deactivation of the first cathode in the first mono cell and the half cell is necessary based on the number of first and second mono cells before the deactivation step in the 9th paragraph.

15. In the 14th paragraph, the determination step is a method for manufacturing an electrode assembly, wherein, when the number of the first and second mono cells is less than a predetermined value, it is determined that deactivation of the first cathode in the first mono cell and the half cell is necessary.

16. In the 14th paragraph, the determination step is a method for manufacturing an electrode assembly, wherein, when the number of the first and second mono cells is less than 15, it is determined that deactivation of the first cathode in the first mono cell and the half cell is necessary.

17. A method for manufacturing an electrode assembly, comprising a judgment step of judging whether deactivation of the first cathode in the first mono cell and the half cell is necessary based on the ratio (A / B) before the deactivation step in the 11th paragraph.

18. In the 17th paragraph, the judgment step is a method for manufacturing an electrode assembly, wherein if the ratio (A / B) is 1.1 or more, it is determined that deactivation of the first cathode in the first mono cell and the half cell is necessary.

19. A first mono cell in which a first cathode, a separator, and an anode are sequentially laminated, each having an inactive region having a predetermined width (w) formed along one edge of a separator; A plurality of second mono cells are laminated on the first mono cell, and a separator, a second cathode, a separator, and an anode are laminated in sequence; and It is stacked on the second monocell placed at the top, and includes a separator, a first cathode having an inactive region formed thereon, and a half-cell in which the separator is sequentially stacked. The width (w) of the above inactive area is 0.9P 2 1.2P inland 2 Within the range, Above P 2 The electrode assembly is calculated by the following formula 4: [Formula 4] In the above formula 4, a 2 is the transverse length of the first cathode, and b 2 is the vertical length of the first cathode, and c 2 are the numbers of first and second mono cells.

20. A first mono cell in which a first cathode, a separator, and an anode are sequentially laminated, each having an inactive region having a predetermined width (w) formed along one edge of a separator; A plurality of second mono cells are laminated on the first mono cell, and a separator, a second cathode, a separator, and an anode are laminated in sequence; and It is stacked on the second monocell placed at the top, and includes a separator, a first cathode having an inactive region formed thereon, and a half-cell in which the separator is sequentially stacked. If the ratio (A / B) of the sum of the areas of the faces of the plurality of cathodes (A) and the sum of the areas of the faces of the plurality of anodes (B) in the electrode assembly is 1.1 or more and less than 1.2, the width (w) of the deactivated region is 1.0X 3 1.25X inland 3 Within the range, If the ratio (A / B) of the sum of the areas of the faces of multiple cathodes (A) and the sum of the areas of the faces of multiple anodes (B) in the electrode assembly is 1.2 or more, the width (w) of the deactivated region is 1.0X 4 Inside 1.5X 4 Within the range, Above X 3 and X 4 The electrode assembly is calculated by the following equations 5 and 6, respectively: [Formula 5] (Y 2 -X 3 )·(Z 2 -X 3 )=Y 2 ·Z 2 ·0.85 [Formula 6] (Y 2 -X 4 )·(Z 2 -X 4 )=Y 2 ·Z 2 ·0.8 In the above formulas 5 and 6, Y 2 is the transverse length of the first cathode, and Z 2 is the vertical length of the first cathode.

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