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

Abstract

The present invention provides a method for deactivating a pair of outermost negative electrodes disposed at the uppermost end and the lowermost end of an electrode assembly including a plurality of positive electrodes, a plurality of negative electrodes, and a plurality of separators, respectively, the method for deactivating the outermost layer negative electrode includes: a deactivating step of forming a deactivating region having a predetermined width (w) along an edge of one side of the outermost layer negative electrode; 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 individual cells in the electrode assembly consisting of the separator, the negative electrode, the separator, and the positive electrode, whereby a clear guidance can be provided for the deactivation operation of the outermost negative electrode of the electrode assembly.

Description

Technical Field

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

[0002] With the technological development and increasing demand for mobile devices, the demand for secondary batteries as energy sources has rapidly increased, and among such secondary batteries, lithium secondary batteries have been commercialized and widely used, which exhibit high energy density and operating potential, and have long cycle life and low self-discharge rate.

[0003] In addition, as concerns about environmental issues increase, many studies have been conducted on electric vehicles and hybrid electric vehicles that can replace vehicles (such as gasoline vehicles and diesel vehicles) that use fossil fuels (which are one of the main causes of air pollution). Nickel-metal hydride secondary batteries are mainly used as power sources for such electric vehicles and hybrid electric vehicles, but research using lithium secondary batteries with high energy density and discharge voltage has been actively conducted, and some have already been commercialized.

[0004] Secondary batteries are classified depending on which structure an electrode assembly having a positive electrode / separator / negative electrode structure has, and are representatively divided into: rolled (wound) electrode assemblies in which long sheet-like positive and negative electrodes are rolled up with a separator interposed therebetween; stacked (laminated) electrode assemblies in which a plurality of positive and negative electrodes cut into units of predetermined sizes are sequentially stacked with a separator interposed therebetween; and stacked / folded electrode assemblies in which the winding and lamination types are combined.

[0005] Such secondary batteries are generally manufactured by embedding an electrode assembly consisting of a positive electrode plate and a negative electrode plate, in which positive and negative electrode active materials are coated, and a separator interposed therebetween, into a pouch-type case made of an aluminum laminate sheet.

[0006] The secondary battery thus manufactured performs an activation process for charge and discharge.

[0007] During activation, lithium moves between the remaining electrodes except for a pair of outermost negative electrodes located at the uppermost and lowermost ends of the electrode assembly, the separator, and the electrolyte, and charge and discharge reactions (hereinafter referred to as main reactions) occur.

[0008] Meanwhile, in the outermost negative electrode, local reactions occur, which involve the charging and discharging of adjacent electrodes without participating in the main reaction.

[0009] For example, the outermost negative electrode is charged while lithium is introduced due to diffusion through the electrolyte, wherein a potential difference occurs between the edge and the middle portion of the outermost negative electrode, thereby causing a side reaction.

[0010] If the local reaction accounts for a certain ratio or higher relative to the main reaction, there are problems of unnecessary electrolyte consumption and unevenness of the entire electrode assembly.

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

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

[0013] It is advantageous in terms of efficiency to selectively perform the deactivation operation only when the local reaction has a certain ratio or higher than the main reaction, but there is currently no clear guide for determining whether to perform the deactivation operation of the outermost negative electrode. Summary of the Invention

[0014] Technical issues

[0015] The problem to be solved by the present invention is to provide a method for deactivating the outermost negative electrode in an electrode assembly, a method for manufacturing the electrode assembly, and an electrode assembly manufactured by the manufacturing method, which can provide clear guidance related to the deactivation operation of the outermost negative electrode.

[0016] Technical Solution

[0017] In order to solve this problem, according to an example of the present invention, a deactivation method for a pair of outermost negative electrodes is provided, wherein the pair of outermost negative electrodes are respectively arranged at the uppermost end and the lowermost end of an electrode assembly including multiple positive electrodes, multiple negative electrodes and multiple separators, wherein the deactivation method of the outermost negative electrode includes a deactivation step of forming a deactivation area with a predetermined width (w) along the edge of one side of the outermost negative electrode, wherein, in the deactivation step, the width (w) is determined based on the horizontal length of the outermost negative electrode, the vertical length of the outermost negative electrode and the number of single monomers consisting of separators, negative electrodes, separators and positive electrodes in the electrode assembly.

[0018] In the deactivation method of the outermost negative electrode, in the deactivation step, the width (w) is determined to be in the range of 0.9P1 to 1.2P1, where P1 can be calculated by the following equation 1:

[0019] [Equation 1]

[0020]

[0021] In the above Equation 1, a1 is the horizontal length of the outermost negative electrode, b1 is the vertical length of the outermost negative electrode, and c1 is the number of single units consisting of separator, negative electrode, separator and positive electrode in the electrode assembly.

[0022] In addition, in the deactivation method of the outermost negative electrode, in the deactivation step, the width (w) may be determined based on a ratio (A / B) of the sum of the areas (A) of one side of the plurality of negative electrodes to the sum of the areas (B) of one side of the plurality of positive electrodes in the electrode assembly.

[0023] Furthermore, in the deactivation method of the outermost negative electrode, in the deactivation step, when the ratio (A / B) is 1.1 or greater to less than 1.2, the width (w) is determined to be within a range of 1.0X1 to 1.25X1, where X1 can be calculated by the following equation 2:

[0024] [Equation 2]

[0025]

[0026] In Equation 2 above, Y1 is the horizontal length of the outermost negative electrode, and Z1 is the vertical length of the outermost negative electrode.

[0027] Furthermore, in the deactivation method of the outermost negative electrode, in the deactivation step, when the ratio (A / B) is 1.2 or greater, the width (w) is determined to be within a range of 1.0X2 to 1.5X2, where X2 can be calculated by the following Equation 3:

[0028] [Equation 3]

[0029]

[0030] In the above equation 3, Y2 is the horizontal length of the outermost negative electrode, and Z2 is the vertical length of the outermost negative electrode.

[0031] Furthermore, in the deactivation method of the outermost negative electrode, the deactivated region may be formed by pasting an insulating tape or coating an insulating material.

[0032] Furthermore, in the deactivation method of the outermost negative electrode, the insulating tape may have a polyimide layer formed on one side or both sides.

[0033] Furthermore, in the deactivation method of the outermost negative electrode, the insulating material may include an epoxy compound or aluminum oxide.

[0034] According to another example of the present invention, a method for manufacturing an electrode assembly is provided, which includes: a deactivation step of forming a deactivation region having a predetermined width (w) along an edge of one side of a first negative electrode; a step of sequentially stacking a separator, a first negative electrode on which the deactivation region is formed, a separator, and a positive electrode to manufacture a first single monomer; a step of sequentially stacking a separator, a second negative electrode on which no deactivation region is formed, a separator, and a positive electrode to manufacture a plurality of second single monomers; a step of sequentially stacking a separator, a first negative electrode on which the deactivation region is formed, and a separator to manufacture a half monomer; a step of sequentially stacking a plurality of second single monomers on a first single monomer to manufacture a stack; and a step of stacking a half monomer on a second single monomer disposed at the uppermost end of the stack to manufacture an electrode assembly, wherein, in the deactivation step, the width (w) is determined based on the horizontal length of the first negative electrode, the vertical length of the first negative electrode, and the number of first single monomers and second single monomers in the electrode assembly.

[0035] Furthermore, in the method of manufacturing the electrode assembly, in the deactivation step, the width (w) is determined to be within a range of 0.9P2 to 1.2P2, where P2 can be calculated by the following Equation 4:

[0036] [Equation 4]

[0037]

[0038] In the above Equation 4, a2 is the horizontal length of the first negative electrode, b2 is the vertical length of the first negative electrode, and c2 is the number of the first single cell and the second single cell.

[0039] In addition, in the manufacturing method of the electrode assembly, in the deactivation step, the width (w) may be determined based on a ratio (A / B) of a sum of areas (A) of one side of a plurality of negative electrodes to a sum of areas (B) of one side of a plurality of positive electrodes in the electrode assembly.

[0040] Furthermore, in the manufacturing method of the electrode assembly, in the deactivation step, when the ratio (A / B) is 1.1 or greater to less than 1.2, the width (w) is determined to be within a range of 1.0X3 to 1.25X3, where X3 can be calculated by the following Equation 5:

[0041] [Equation 5]

[0042]

[0043] In the above Equation 5, Y2 is the horizontal length of the first cathode, and Z2 is the vertical length of the first cathode.

[0044] Furthermore, in the manufacturing method of the electrode assembly, in the deactivation step, when the ratio (A / B) is 1.2 or greater, the width (w) is determined to be within a range of 1.0X4 to 1.5X4, where X4 can be calculated by the following Equation 6:

[0045] [Equation 6]

[0046]

[0047] In the above Equation 4, Y2 is the horizontal length of the first cathode, and Z2 is the vertical length of the first cathode.

[0048] Furthermore, in the manufacturing method of the electrode assembly, before the deactivation step, the manufacturing method may include a determination step of determining whether deactivation of the first negative electrode in the first single cell and the half cell is necessary based on the number of the first single cell and the second single cell.

[0049] Furthermore, in the manufacturing method of the electrode assembly, it may be determined in the determining step that deactivation of the first negative electrode in the first single cell and the half cell is necessary when the number of the first single cell and the second single cell is less than a predetermined value.

[0050] Furthermore, in the manufacturing method of the electrode assembly, it may be determined in the determining step that when the number of the first single cell and the second single cell is less than 15, deactivation of the first negative electrode in the first single cell and the half cell is necessary.

[0051] Furthermore, in the manufacturing method of the electrode assembly, before the deactivation step, it may include a determination step of determining whether deactivation of the first negative electrode in the first single cell and the half cell is necessary based on the ratio (A / B).

[0052] Furthermore, in the manufacturing method of the electrode assembly, it may be determined in the determining step that deactivation of the first negative electrode in the first single cell and the half cell is necessary when the ratio (A / B) is 1.1 or greater.

[0053] According to another example of the present invention, there is provided an electrode assembly including: a first single cell obtained by sequentially stacking a separator, a first negative electrode having a deactivation region having a predetermined width (w) formed thereon along an edge of one side, the separator, and a positive electrode; a plurality of second single cells stacked on the first single cell and obtained by sequentially stacking a separator, a second negative electrode, the separator, and a positive electrode; and a half cell stacked on the second single cell disposed at an uppermost end and obtained by sequentially stacking a separator, the first negative electrode having a deactivation region formed thereon, and the separator, wherein the width (w) of the deactivation region is in a range of 0.9P2 to 1.2P2, and P2 is calculated by the following Equation 4:

[0054] [Equation 4]

[0055]

[0056] In the above Equation 4, a2 is the horizontal length of the first negative electrode, b2 is the vertical length of the first negative electrode, and c2 is the number of the first single cell and the second single cell.

[0057] According to another embodiment of the present invention, there is provided an electrode assembly including: a first single cell obtained by sequentially stacking a separator, a first negative electrode having a deactivated region having a predetermined width (w) formed thereon along an edge of one side, a separator, and a positive electrode; a plurality of second single cells stacked on the first single cell and obtained by sequentially stacking a separator, a second negative electrode, a separator, and a positive electrode; and a half cell stacked on the second single cell disposed at an uppermost end and obtained by sequentially stacking a separator, the first negative electrode having a deactivated region formed thereon, and a separator, wherein , when the ratio (A / B) of the sum of the areas (A) of one side of the plurality of negative electrodes to the sum of the areas (B) of one side of the plurality of positive electrodes in the electrode assembly is 1.1 or greater to less than 1.2, the width (w) of the deactivated region is in the range of 1.0×3 to 1.25×3, and when the ratio (A / B) of the sum of the areas (A) of one side of the plurality of negative electrodes to the sum of the areas (B) of one side of the plurality of positive electrodes in the electrode assembly is 1.2 or greater, the width (w) of the deactivated region is in the range of 1.0×4 to 1.5×4, where X3 and X4 are calculated by the following equations 5 and 6, respectively:

[0058] [Equation 5]

[0059]

[0060] [Equation 6]

[0061]

[0062] In the above equations 5 and 6, Y2 is the horizontal length of the first cathode, and Z2 is the vertical length of the first cathode.

[0063] Beneficial effects

[0064] The present invention can provide clear guidance related to the deactivation operation of the outermost negative electrode in an electrode assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is a diagram illustrating a stacked structure of an electrode assembly according to one example of the present invention.

[0066] Figure 2 It is a diagram showing the deactivated region of the outermost negative electrode.

[0067] Figure 3 is a diagram showing a single cell and a half cell including a double-sided electrode in which two single-sided electrodes are bound.

[0068] Figure 4 is a diagram used to explain local reactions and main reactions in an electrode assembly during activation. DETAILED DESCRIPTION

[0069] Hereinafter, a method of deactivating an outermost negative electrode according to an example of the present invention will be described in detail with reference to the accompanying drawings.

[0070] Figure 1 is a diagram showing a stacked structure of an electrode assembly according to one example of the present invention, Figure 2 is a diagram showing the deactivated region of the outermost negative electrode, and Figure 3 is a diagram showing a single cell and a half cell including a double-sided electrode in which two single-sided electrodes are bound.

[0071] The present invention relates to a method for deactivating a pair of outermost negative electrodes (102-1) respectively arranged at the uppermost end and the lowermost end of an electrode assembly (100). The electrode assembly comprises a plurality of positive electrodes (103), a plurality of negative electrodes (102), and a plurality of separators (101).

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

[0073] In the deactivation step, the width (w) is determined based on the horizontal length of the outermost negative electrode (102-1), the vertical length of the outermost negative electrode (102-1), and the number of single units (110) consisting of the separator (101), the negative electrode (102), the separator (101), and the positive electrode (103) in the electrode assembly (100).

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

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

[0076] In the electrode assembly (100), the first single cell (110-1) may be disposed at the lowermost end, and the half cell (130) may be disposed at the uppermost end.

[0077] In the present invention, in order to distinguish the single cell disposed at the lowermost end from other single cells, the single cell disposed at the lowermost end is referred to as a first single cell ( 110 - 1 ), and the other single cells are referred to as second single cells ( 110 - 2 ).

[0078] The first single cell (110-1) and the second single cell (110-2) are distinguished based on whether a deactivation region is formed in the negative electrode. The first single cell (110-1) may include a first negative electrode (102-1) in which a deactivation region is formed, and the second single cell (110-2) may include a second negative electrode (102-2) in which a deactivation region is not formed.

[0079] In the present invention, the first negative electrode (102-1) in which the deactivated region (104) is formed is the outermost negative electrode. Therefore, the reference numeral of the first negative electrode will be used as '102-1', which is the same as the outermost negative electrode. In addition, in order to distinguish the outermost negative electrode from the remaining negative electrode, the remaining negative electrode will be referred to as the second negative electrode (102-2).

[0080] In the present invention, the outermost negative electrode (102-1) may mean the negative electrode of the first single cell (110-1) and the negative electrode of the half cell (130) located at the lowermost end of the stack (120).

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

[0082] That is, in the present invention, a deactivation step may be performed before manufacturing the single monomer ( 110 ) and the half monomer ( 130 ).

[0083] For example, the first single cell (110-1) disposed at the lowermost end and the half cell (130) disposed at the uppermost end can be manufactured by laminating the outermost negative electrode (102-1) in which the deactivated region is formed by the deactivation step according to the method according to the present invention and the separator (101).

[0084] In the present invention, the positive electrode (103) or the negative electrode (102) has one side of a rectangle formed by a pair of long sides and a pair of short sides. In the present invention, the horizontal length of the outermost negative electrode means the length of the long side, and the vertical length of the outermost negative electrode means the length of the short side.

[0085] Furthermore, in the present invention, one side of the electrode has a rectangular shape, and in the present invention, it should be understood that the one side of the electrode does not include an electrode tab formed to protrude out of the cross section of the rectangle.

[0086] Since the width (w) is determined based on the horizontal length of the outermost negative electrode (102-1), the vertical length of the outermost negative electrode (102-1), and the number of single units (110) consisting of the separator (101), the negative electrode (102), the separator (101), and the positive electrode (103) in the electrode assembly (100), it is possible to ensure a minimum deactivation area without deteriorating battery performance, and therefore it is possible to expect an effect of reducing the manufacturing cost consumed when forming the deactivation area.

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

[0088] [Equation 1]

[0089]

[0090] In the above equation 1, a1 is the horizontal length of the outermost negative electrode (102-1), b1 is the vertical length of the outermost negative electrode (102-1), and c1 is the number of single cells (110) consisting of the separator (101), the negative electrode (102), the separator (101), and the positive electrode (103) in the electrode assembly (100).

[0091] In the above Equation 1, c1 may be a natural number smaller than 15, and may be a natural number of 2 to 14, for example.

[0092] The number of single cells (110) may be predetermined before manufacturing the electrode assembly (100), and thus the width of the deactivated region may be adjusted in consideration of the c1 value in a deactivation step performed before manufacturing the single cells (110) and the half cells (130).

[0093] For example, when manufacturing an electrode assembly (100) having 14 single cells (110), the deactivation step may adjust the width of the deactivated region using a p value calculated by substituting 14 into c of Equation 1 above.

[0094] In addition, the width of the deactivated region (104) may be in mm or cm.

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

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

[0097] In one example, the deactivated region (104) may be formed on a side of the negative electrode that contacts the outermost separator.

[0098] Specifically, in the first single cell (110-1) located at the lowermost end, the first separator (101-1), the outermost negative electrode (102-1), the second separator (101-2) and the positive electrode (103) can be stacked sequentially, and the deactivation region (104) can be formed on the side (102-1a) of the outermost negative electrode (102-1) facing the first separator (101-1).

[0099] Furthermore, in the half cell (130) located at the uppermost end, the third separator (101-3), the outermost negative electrode (102-1) and the fourth separator (101-4) may be sequentially stacked, and the deactivation region (104) may be formed on a side (102-1a) of the outermost negative electrode (102-1) facing the fourth separator (101-4).

[0100] Figure 3 is a diagram showing a single cell and a half cell including a double-sided electrode in which two single-sided electrodes are bound.

[0101] refer to Figure 3 , the positive electrode may be a double-sided positive electrode in which two single-sided positive electrodes are bound, and the negative electrode may be a double-sided negative electrode in which two single-sided negative electrodes are bound.

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

[0103] Meanwhile, in the case of a double-sided anode in which two single-sided anodes are bound, the deactivation region ( 104 ) may be formed on one side of the single-sided anode relatively located at the outermost layer.

[0104] For example, Figure 3As shown in (a), in the half-cell (130) located at the uppermost end, the third separator (101-3), the third single-sided negative electrode (102a), the fourth single-sided negative electrode (102b) and the fourth separator (101-4) can be stacked sequentially, and the deactivation region (104) can be formed on the side of the second single-sided negative electrode (102b) facing the fourth separator (101-4).

[0105] In addition, if Figure 3 As shown in (b), in the first single monomer (110-1) located at the lowermost end, the first separator (101-1), the first single-sided negative electrode (102a), the second single-sided negative electrode (102b), the second separator (101-2), the first single-sided positive electrode (103a) and the second single-sided positive electrode (103b) can be stacked sequentially, and the deactivation region (104) can be formed on the side of the first single-sided negative electrode (102a) facing the first separator (101).

[0106] Furthermore, for NP ratio (ratio of negative electrode capacity to positive electrode capacity per unit area) inversion and lithium plating prevention, the area of ​​the negative electrode (102) may be larger than that of the positive electrode (103).

[0107] In one example, in the deactivation step, the width (w) may be determined based on a ratio (A / B) of a sum of areas (A) of one side of the plurality of negative electrodes (102) to a sum of areas (B) of one side of the plurality of positive electrodes (103) in the electrode assembly (100).

[0108] Since the width (w) is determined based on the ratio (A / B), a minimum deactivation region can be ensured without deteriorating battery performance, and thus a reduction effect of manufacturing costs consumed when forming the deactivation region can be expected.

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

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

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

[0112] Furthermore, the total area of ​​one side of the plurality of negative electrodes (A) can be calculated by multiplying the area of ​​one side of the negative electrode by the number of negative electrodes, and the total area of ​​one side of the plurality of positive electrodes (B) can be calculated by multiplying the area of ​​one side of the positive electrode by the number of positive electrodes.

[0113] In addition, the electrode assemblies of Table 1 and Table 3 were manufactured by laminating two single cells and one half cell, in which the number of positive electrodes was two and the number of negative electrodes was three.

[0114] In addition, the electrode assembly of Table 2 was manufactured by laminating four single cells and one half cell, in which the number of positive electrodes was four and the number of negative electrodes was five.

[0115] Hereinafter, in Tables 1 to 3, “the number of single cells in the electrode assembly” is the sum of the number of the first single cell ( 110 - 1 ) and the second single cell ( 110 - 2 ).

[0116] [Table 1]

[0117]

[0118] [Table 2]

[0119]

[0120] [Table 3]

[0121]

[0122] Referring to Table 1 and Table 2 above, it can be confirmed that when the number of single cells in the electrode assembly increases from 2 to 4, the ratio (A / B) decreases from 1.59 to 1.32.

[0123] In addition, referring to Table 1 and Table 3, it can be confirmed that when the positive electrode area is increased from 12 cm 2 Increased to 160cm 2 And the negative electrode area is from 12.71cm 2 Increased to 162.81cm 2 , the ratio (A / B) decreases from 1.59 to 1.53.

[0124] From Tables 1 to 3 above, it can be confirmed that the ratio (A / B) decreases as the number of single 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.

[0125] In addition, if the number of single cells in the electrode assembly increases, the ratio of the electrode participating in the main reaction increases, and thus the ratio of the local reaction compared to the main reaction may be reduced.

[0126] Similarly, as the area of ​​one side of the positive electrode or the area of ​​one side of the negative electrode increases, the ratio of the electrode participating in the main reaction increases, thereby reducing the local reaction ratio compared to the main reaction. When the local reaction ratio is reduced to a negligible level, the deactivation operation may not be necessary.

[0127] Therefore, the ratio (A / B) can be used as an indicator capable of quantitatively analyzing the local reaction ratio because it is linked to the number of single cells in the electrode assembly and the area of ​​one side of the electrode, which affect the local reaction ratio.

[0128] The present invention can quantitatively analyze whether the local reaction ratio is negligible through the ratio (A / B), and based on this, can form the deactivation area to an optimal size capable of minimizing the use of unnecessary deactivation materials.

[0129] In one example, in the deactivation step, when the ratio (A / B) is 1.1 or greater to less than 1.2, the width (w) is determined to be within a range of 1.0X1 to 1.25X1, where X1 can be calculated by the following Equation 2:

[0130] [Equation 2]

[0131]

[0132] In the above Equation 2, Y1 is the horizontal length of the outermost negative electrode (102-1), and Z1 is the vertical length of the outermost negative electrode (102-1).

[0133] In another example, in the deactivation step, when the ratio (A / B) is 1.2 or greater, the width (w) is determined to be within a range of 1.0X2 to 1.5X2, where X2 can be calculated by the following Equation 3:

[0134] [Equation 3]

[0135]

[0136] In the above Equation 3, Y2 is the horizontal length of the outermost negative electrode (102-1), and Z2 is the vertical length of the outermost negative electrode (102-1).

[0137] In the above equations 3 and 4, the units of the horizontal length of the outermost negative electrode ( 102 - 1 ) and the vertical length of the outermost negative electrode ( 102 - 1 ) may be mm or cm.

[0138] Since the width (w) is determined differently based on the ratio (A / B), the local reaction can provide a size of the optimal deactivation region (104) where the local reaction is negligible compared to the main reaction, thereby minimizing the use of unnecessary deactivation material.

[0139] In one example, the deactivated area (104) may be formed by attaching an insulating tape or coating an insulating material.

[0140] The application of the insulating material may be performed using various known coating methods such as, but not limited to, spray coating and die coating.

[0141] The 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 adhesiveness and insulating properties, thereby being able to exhibit excellent effects in deactivating the outermost negative electrode (102-1).

[0142] The insulating material may include epoxy or aluminum oxide.

[0143] The present invention also relates to a method for manufacturing an electrode assembly. This method combines the above-described method for deactivating the outermost negative electrode. Therefore, detailed descriptions that overlap with the above descriptions will be omitted.

[0144] With reference to the accompanying drawings, the manufacturing method includes: a deactivation step of forming a deactivation region (104) having a predetermined width (w) along an edge of one side of a first negative electrode (102-1); a step of sequentially stacking a separator (101), a first negative electrode (102-1) on which the deactivation region 104 is formed, a separator (101), and a positive electrode (103) to manufacture a first single monomer (110-1); a step of sequentially stacking a separator (101), a second negative electrode (102-2) on which no deactivation region is formed, a separator (101), and a positive electrode (103) to manufacture a plurality of second single monomers (110-2); a step of sequentially stacking a separator (101), a first negative electrode (102-1) on which the deactivation region 104 is formed, a separator (101), and a positive electrode (103) to manufacture a plurality of second single monomers (110-2); The invention relates to a method for manufacturing an electrode assembly (100) comprising: forming a first negative electrode (102-1) in a deactivated region, and a separator (101) to manufacture a half-cell; a step of sequentially stacking a plurality of second single cells (110-2) on the first single cell (110-1) to manufacture a stacked body (120); and a step of stacking a half-cell (130) on the second single cell (110-2) arranged at the uppermost end of the stacked body (120) to manufacture an electrode assembly (100), wherein, in the deactivation step, the width (w) is determined based on the horizontal length of the first negative electrode (102-1), the vertical length of the first negative electrode (102-1), and the number of the first single cell (110-1) and the second single cell (110-2).

[0145] In one example, in the deactivation step, the width (w) is determined to be in the range of 0.9P2 to 1.2P2, where P2 can be calculated by the following equation 4:

[0146] [Equation 4]

[0147]

[0148] In the above Equation 4, a2 is the horizontal length of the first negative electrode, b2 is the vertical length of the first negative electrode, and c2 is the number of the first single cell and the second single cell.

[0149] Furthermore, in the deactivation step, the width (w) may be determined based on a ratio (A / B) of a sum of areas (A) of one side of the plurality of negative electrodes (102) to a sum of areas (B) of one side of the plurality of positive electrodes (103) in the electrode assembly (100).

[0150] In one example, in the deactivation step, when the ratio (A / B) is 1.1 or greater to less than 1.2, the width (w) is determined to be within a range of 1.0X3 to 1.25X3, where X3 can be calculated by the following Equation 5:

[0151] [Equation 5]

[0152]

[0153] In the above Equation 5, Y2 is the horizontal length of the first cathode (102-1), and Z2 is the vertical length of the first cathode (102-1).

[0154] In another example, in the deactivation step, when the ratio (A / B) is 1.2 or greater, the width (w) is determined to be within a range of 1.0X4 to 1.5X4, where X4 can be calculated by the following Equation 6:

[0155] [Equation 6]

[0156]

[0157] In the above Equation 6, Y2 is the horizontal length of the first cathode (102-1), and Z2 is the vertical length of the first cathode (102-1).

[0158] In the above Equations 5 and 6, the units of the horizontal length of the first negative electrode ( 102 - 1 ) and the vertical length of the first negative electrode ( 102 - 1 ) may be mm or cm.

[0159] In a specific example, before the deactivation step, it may include a determination step of determining whether deactivation of the first negative electrode (102-1) in the first single cell (110-1) and the half cell (130) is necessary based on the number of the first single cell (110-1) and the second single cell (110-2).

[0160] When it is determined according to the determining step that deactivation of the electrode assembly (100) is necessary, the method according to the present invention determines the width (w) of the deactivation region (104) in the deactivation step based on the horizontal length of the first negative electrode (102-1), the vertical length of the first negative electrode (102-1), and the number of the first single cell (110-1) and the second single cell (110-2), thereby reducing resistance due to local reaction while minimizing the use of unnecessary materials in the deactivation region, thereby preventing the performance of the battery (lithium secondary battery) from being deteriorated, a detailed description of which will be provided below.

[0161] When the number of the first single cell (110-1) and the second single cell (110-2) is less than a predetermined value, the determining step may determine that deactivation of the first negative electrode (102-1) in the first single cell (110-1) and the half cell (130) is necessary.

[0162] Specifically, when the number of the first single cell (110-1) and the second single cell (110-2) is less than 15, the determining step may determine that deactivation of the first negative electrode (102-1) in the first single cell (110-1) and the half cell (130) is necessary.

[0163] That is, when the sum of the numbers of the first single cell (110-1) and the second single cell (110-2) is within the range of 2 to 14, the determining step may determine that deactivation of the first negative electrode (102-1) in the first single cell (110-1) and the half cell (130) is necessary.

[0164] In other words, the deactivation step according to the method of the present invention may be performed when manufacturing an electrode assembly in which the sum of the numbers of the first single cell ( 110 - 1 ) and the second single cell ( 110 - 2 ) is less than 15, for example, in the range of 2 to 14.

[0165] Figure 4 is a diagram used to explain local reactions and main reactions in an electrode assembly during activation.

[0166] refer to Figure 4 During activation, the first negative electrode (102-1) reacts with the adjacent electrode, thereby causing local reactions involved in charging and discharging. Then, while lithium moves between the electrodes, separator, and electrolyte within the remaining single cell (110) excluding the first negative electrode (102-1), charging and discharging reactions (main reactions) occur.

[0167] In particular, when the number of single cells (110) within the electrode assembly (100) is less than 15, the ratio of the local reaction increases to a certain extent or more compared to the main reaction. Therefore, unnecessary electrolyte consumption and unevenness of the electrode assembly occur, and the resistance value in the secondary battery increases, thereby possibly causing a problem of reduced output of the secondary battery.

[0168] In order to solve such a problem, when the number of the first single cell (110-1) and the second single cell (110-2) is less than 15, the determining step determines that deactivation of the first negative electrode (102-1) in the first single cell (110-1) and the half cell (130) is necessary, and the deactivation step can be performed.

[0169] On the other hand, when the number of the first single monomer (110-1) and the second single monomer (110-2) is 15 or more, the determining step may determine that deactivation is unnecessary. When the number of the first single monomer (110-1) and the second single monomer (110-2) is 15 or more, the ratio of the local reaction is reduced to a certain level or lower compared to the main reaction, whereby the local reaction is negligible, so that even if the deactivation operation is not performed, it may not be a big problem.

[0170] In terms of the main reaction and the local reaction, the deactivation step determines the width (w) of the deactivation region (104) based on the horizontal length of the first negative electrode (102-1), the vertical length of the first negative electrode (102-1), and the number of the first single monomer (110-1) and the second single monomer (110-2) according to the above equation 2, thereby providing an optimal size of the deactivation region (104) in which the local reaction is negligible compared to the main reaction, thereby minimizing unnecessary material consumption in the deactivation region (104).

[0171] Furthermore, the method according to the present invention may include a determination step of determining whether deactivation of the first negative electrode (102-1) in the first single cell (110-1) and the half cell (130) is necessary based on the ratio (A / B) before the deactivation step.

[0172] If it is determined in the determining step that deactivation is necessary, the deactivation step may form a deactivated region (104).

[0173] When the ratio (A / B) is 1.1 or greater, the determining step may determine that deactivation of the first negative electrode ( 102 - 1 ) in the first single cell ( 110 - 1 ) and the half cell ( 130 ) is necessary.

[0174] When it is determined according to the determining step that deactivation of the electrode assembly (100) is necessary, the method according to the present invention determines the width (w) of the deactivation region (104) in the deactivation step based on the ratio (A / B), thereby reducing resistance due to local reaction while minimizing the use of unnecessary materials in the deactivation region, thereby preventing battery (lithium secondary battery) performance degradation.

[0175] refer to Figure 4 During activation, the first negative electrode (102-1) reacts with the adjacent electrode, thereby causing local reactions involved in charging and discharging. Then, while lithium moves between the electrodes, separator, and electrolyte within the remaining single cell (110) excluding the first negative electrode (102-1), charging and discharging reactions (main reactions) occur.

[0176] In particular, when the ratio (A / B) is 1.1 or greater, the ratio of the local reaction increases to a certain extent or more compared to the main reaction. As a result, unnecessary electrolyte consumption and unevenness of the electrode assembly occur, and the resistance value in the secondary battery increases, thereby potentially causing a problem of reduced secondary battery output.

[0177] In order to solve such a problem, when the ratio (A / B) is 1.1 or greater, the determining step determines that deactivation of the first negative electrode ( 102 - 1 ) is necessary, and the deactivation step can be performed.

[0178] On the other hand, when the ratio (A / B) is less than 1.1, the determination step may determine that deactivation is unnecessary. When the ratio (A / B) is less than 1.1, the ratio of the local reaction is reduced to a certain level or less compared to the main reaction, whereby the local reaction is negligible, so that even if the deactivation operation is not performed, it may not be a big problem.

[0179] In terms of the main reaction and the local reaction, the deactivation step differently determines the width (w) of the deactivated region (104) based on the ratio (A / B) according to the above equations 5 and 6, thereby providing an optimal size of the deactivated region (104) in which the local reaction is negligible compared to the main reaction, thereby minimizing unnecessary material consumption of the deactivated region (104).

[0180] The present invention also relates to an electrode assembly. The electrode assembly can be manufactured by the above method.

[0181] The 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 end and the lowermost end, respectively.

[0182] Specifically, the electrode assembly (100) includes: a first single unit (110-1) obtained by sequentially stacking a separator (101), a first negative electrode (102-1) having a deactivated region (104) having a predetermined width (w) formed thereon along an edge of one side, the separator (101), and a positive electrode (103); a first single unit (110-1) obtained by sequentially stacking a separator (101), a second negative electrode (102-2), the separator (101), and a positive electrode (103); a plurality of second single cells (110-2) obtained by stacking a first negative electrode (102-1) having a deactivated region formed thereon, and a separator (101); and a half cell (130) stacked on the second single cell (110-2) disposed at the uppermost end and obtained by sequentially stacking a separator (101), a first negative electrode (102-1) having a deactivated region formed thereon, and the separator (101), wherein the deactivated region (104) has a width (w) in the range of 0.9P2 to 1.2P2, wherein P2 can be calculated by the following equation 4:

[0183] [Equation 4]

[0184]

[0185] In the above Equation 4, a2 is the horizontal length of the first negative electrode, b2 is the vertical length of the first negative electrode, and c2 is the number of the first single cell and the second single cell.

[0186] In one example, the number of the first single cell ( 110 - 1 ) and the second single cell ( 110 - 2 ) may be less than fifteen.

[0187] As described above, when the number of the first single monomer (110-1) and the second single monomer (110-2) is less than 15, problems due to local reaction may occur, making it necessary to form the deactivation region (104), wherein the width (w) of the deactivation region (104) is determined according to Equation 2, thereby preventing problems due to local reaction while minimizing unnecessary material usage of the deactivation region.

[0188] In one example, the deactivation region (104) may include an insulating tape attached along an edge of one side of the first negative electrode (102-1), or an insulating material coated along an edge of the first negative electrode (102-1).

[0189] The insulating material may be applied using various known coating methods such as, but not limited to, spray coating and die coating.

[0190] The 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 adhesiveness and insulating properties, thereby being able to exhibit excellent effects in deactivating the first negative electrode (102-1).

[0191] The insulating material may include epoxy or aluminum oxide.

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

[0193] The 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) disposed at the uppermost end and the lowermost end, respectively.

[0194] Specifically, the electrode assembly (100) includes: a first single monomer (110-1) obtained by sequentially stacking a separator (101), a first negative electrode (102-1) having a deactivation region (104) having a predetermined width (w) formed thereon along an edge of one side, a separator (101), and a positive electrode (103); a plurality of second single monomers (110-2) stacked on the first single monomer (110-1) and obtained by sequentially stacking a separator (101), a second negative electrode (102-2), a separator (101), and a positive electrode (103); and a half monomer (130) stacked on the second single monomer (110-2) disposed at the uppermost end and obtained by sequentially stacking a separator (101), a first negative electrode (102-1) having a deactivation region formed thereon, and a separator (101).

[0195] If the ratio (A / B) of the sum of the areas (A) of one side of the plurality of negative electrodes (102) to the sum of the areas (B) of one side of the plurality of positive electrodes (103) in the electrode assembly is 1.1 or greater to less than 1.2, the width (w) of the deactivated region (104) is in the range of 1.0X3 to 1.25X3.

[0196] Then, a ratio (A / B) of the sum of the areas (A) of one side of the plurality of negative electrodes (102) to the sum of the areas (B) of one side of the plurality of positive electrodes (103) in the electrode assembly is 1.2 or greater, and a width (w) of the deactivated region is in the range of 1.0×4 to 1.5×4, wherein

[0197] X3 and X4 are calculated by the following equations 5 and 6 respectively:

[0198] [Equation 5]

[0199]

[0200] [Equation 6]

[0201]

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

[0203] The electrode assembly (100) that satisfies the condition has an optimal size of a deactivated region (104) in which the local reaction is negligible compared to the main reaction.

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

[0205] The insulating material may be applied using various known coating methods such as, but not limited to, spray coating and die coating.

[0206] The 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 adhesiveness and insulating properties, thereby being able to exhibit excellent effects in deactivating the first negative electrode (102-1).

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

[0208] Hereinafter, the present application is specifically described through examples, but the scope of the present application is not limited to the following examples.

[0209] Manufacturing Example

[0210] Anode manufacturing

[0211] A negative electrode slurry was prepared by mixing artificial graphite:conductive agent:binder in a ratio of 94:1:3, and then the negative electrode was manufactured by sequentially performing applying the slurry on a copper current collector, drying, and rolling.

[0212] Cathode manufacturing

[0213] A positive electrode slurry was prepared by mixing NCM811:carbon black:PVDF in a ratio of 90:5:5, and then a positive electrode was manufactured by sequentially performing applying the slurry on an aluminum current collector, drying, and rolling.

[0214] partition

[0215] Preparation of polyethylene porous separators.

[0216] electrolyte

[0217] The electrolyte was prepared by dissolving 1 M LiPF6 in a mixed solvent in which EC (ethylene carbonate), DMC (dimethyl carbonate), and EMC (ethyl methyl carbonate) were mixed in a volume ratio of 3:4:3.

[0218] Example 1A

[0219] Electrode assembly

[0220] The fabricated negative electrode and positive electrode were cut into 5x7 cm and 5.1x7.1 cm, respectively.

[0221] Then, an insulating tape having a width of 0.5 cm was applied along the edge of the negative electrode to manufacture an outermost electrode having a deactivated region formed thereon.

[0222] A first single monomer obtained by sequentially stacking a separator, an outermost negative electrode (deactivated region O), a separator, and a positive electrode w, and four second single monomers obtained by sequentially stacking a separator, a negative electrode (deactivated region X), a separator, and a positive electrode are stacked to produce a stack including a total of five single monomers.

[0223] Then, a half cell obtained by sequentially stacking a separator, a negative electrode, and a separator is stacked on the single cell located at the uppermost end of the stacked body to manufacture an electrode assembly.

[0224] The electrode assembly manufactured according to Example 1A includes five positive electrodes and six negative electrodes.

[0225] In addition, according to the specifications of the electrode assembly manufactured according to Example 1A, the P1 value is 0.424, which is calculated by substituting 5.1 for a1, 7.1 for b1, and 5 for c1 in Equation 1.

[0226] When the P1 value is 0.424, the range of 0.9P1 to 1.2P1 is calculated to be 0.382 mm to 0.509 mm, confirming that the width of the deactivated region of the electrode assembly manufactured in Example 1A, which is 0.5 cm, is within the range of 0.9P1 to 1.2P1.

[0227] lithium secondary batteries

[0228] The fabricated electrode assembly was placed inside a bag-shaped case, and the electrolyte prepared above was then injected into the case.

[0229] Then, after pre-aging at room temperature for 2 days, they were charged at a charging rate of 0.1 C until the SOC reached 30%, and after aging at room temperature and 60°C for 1 day respectively, a degassing process was performed to discharge the gas inside the shell, thereby manufacturing lithium secondary batteries.

[0230] Example 2A

[0231] 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 on which a deactivation area was formed by applying an insulating tape with a width of 0.35 cm along the edge of the negative electrode, and a stack having a total of 10 single cells was manufactured by stacking one first single cell and nine second single cells.

[0232] The electrode assembly manufactured according to Example 2A included 10 positive electrodes and 11 negative electrodes.

[0233] Furthermore, according to the specifications of the electrode assembly manufactured according to Example 2A, the P1 value is 0.297, which is calculated by substituting 5.1 for a1, 7.1 for b1, and 10 for c1 in Equation 1.

[0234] When the P1 value is 0.297, the range of 0.9P1 to 1.2P1 is calculated as 0.267 mm to 0.357 mm, confirming that the width of the deactivated region of the electrode assembly manufactured according to Example 2A, which is 0.35 cm, is within the range of 0.9P1 to 1.2P1.

[0235] Comparative Example 1A

[0236] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 1A, except that a stacked body including a total of five single cells was manufactured by stacking five second single cells without stacking the first single cell.

[0237] Comparative Example 2A

[0238] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 2A, except that a stacked body including a total of ten single cells was manufactured by stacking ten second single cells without stacking the first single cell.

[0239] Comparative Example 3A

[0240] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 2A, except that a first single unit including a first negative electrode on which a deactivation region was formed by applying an insulating tape having a width of 0.15 cm along an edge of the negative electrode was manufactured.

[0241] According to the specifications of the electrode assembly manufactured in Comparative Example 3A, the P1 value was 0.297, which was calculated by substituting 5.1 for a1, 7.1 for b1, and 10 for c1 in Equation 1.

[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, confirming that the width of the deactivated region of the electrode assembly manufactured in Comparative Example 3A, which is 0.15 cm, is outside the range of 0.9P1 to 1.2P1.

[0243] Comparative Example 4A

[0244] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 1A, except that a stacked body including a total of 15 single cells was manufactured by stacking 15 second single cells without stacking the first single cell.

[0245] For reference, the electrode assembly manufactured according to Comparative Example 4A included 15 positive electrodes and 16 negative electrodes.

[0246] Comparative Example 5A

[0247] An electrode assembly and a lithium secondary battery were manufactured in the same manner as in Example 1A, except that an outermost electrode having a deactivation region was formed thereon by applying an insulating tape having a width of 0.18 mm along the edge of the negative electrode, and a stack including a total of 15 single cells was manufactured by stacking one first single cell and 14 second single cells.

[0248] Experimental Example 1

[0249] 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.

[0250] [Table 4]

[0251]

[0252] The above experimental results confirmed that the lithium secondary batteries manufactured in Examples 1A and 2A had reduced resistance compared to Comparative Examples 1A and 2A. Furthermore, in the case of Comparative Example 3A, it was confirmed that the width of the deactivated region (0.15 mm) did not fall within the range of 0.9P1 to 1.2P1 when converted to the P1 value calculated according to Equation 1, and the effect of the deactivated region was not shown, as the same resistance value as Comparative Example 2A, in which no deactivated region was formed, was shown.

[0253] Then, it can be confirmed from Comparative Examples 4A and 5A that when the total number of the first single monomer and the second single monomer in the electrode assembly is 15 or more, similar resistance values ​​are shown regardless of whether they are deactivated, from which it can be known that when the total number of the first single monomer and the second single monomer is 15 or more, it is unnecessary to form a deactivation area.

[0254] Experimental Example 2

[0255] For the 900 mA pouch secondary battery, the resistance value of the electrode assembly according to the ratio (A / B) was measured. The resistance was measured as the resistance value at 10 seconds under the condition of 2.5 C pulse discharge, and the results are shown in Table 5 below.

[0256] [Table 5]

[0257]

[0258] In Examples 1B and 2B, a deactivated region was formed by attaching an imide tape with a width ranging from 1.0×4 to 1.5×4, based on the X4 value calculated from Equation 6, to the edge of the outermost electrode. In Comparative Examples 1B and 2B, no deactivated region was formed. Examples 1B and 2B exhibited lower resistance values ​​than Comparative Examples 1B and 2B. This confirmed that when the edge of the outermost electrode is deactivated at a ratio (A / B) of 1.1 or greater, localized reactions at the outermost electrode can be prevented.

[0259] The preferred embodiments of the present invention as described above have been disclosed for illustrative purposes, and those skilled in the art with 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 deemed to fall within the scope of the appended claims.

[0260] Description of Reference Signs

[0261] 100: Electrode assembly

[0262] 101: Partition

[0263] 102: Negative electrode

[0264] 103: Positive electrode

[0265] 110: Single monomer

[0266] 120: Laminated body

[0267] 130: Semi-mono

[0268] 102-1: Outermost negative electrode

[0269] 104: Deactivation area

Claims

1. A method for deactivating a pair of outermost negative electrodes, wherein the pair of outermost negative electrodes are respectively arranged at the uppermost end and the lowermost end of an electrode assembly including a plurality of positive electrodes, a plurality of negative electrodes and a plurality of separators, wherein: The deactivation method of the outermost negative electrode includes a deactivation step of forming a deactivation area having a predetermined width (w) along an edge of one side of the outermost negative electrode, and In the deactivation step, the width (w) is determined based on the horizontal length of the outermost negative electrode, the vertical length of the outermost negative electrode, and the number of single units consisting of the separator, the negative electrode, the separator, and the positive electrode in the electrode assembly.

2. The method for deactivating the outermost negative electrode according to claim 1, wherein: In the deactivation step, the width (w) is determined to be in the range of 0.9P1 to 1.2P1, where P1 is calculated by the following equation 1: [Equation 1] Wherein, a1 is the horizontal length of the outermost negative electrode, b1 is the vertical length of the outermost negative electrode, and c1 is the number of single units consisting of the separator, the negative electrode, the separator and the positive electrode in the electrode assembly.

3. The method for deactivating the outermost negative electrode according to claim 1, wherein: In the deactivation step, the width (w) is determined based on a ratio (A / B) of a sum of areas (A) of one side of the plurality of negative electrodes to a sum of areas (B) of one side of the plurality of positive electrodes in the electrode assembly.

4. The method for deactivating the outermost negative electrode according to claim 3, wherein: In the deactivation step, when the ratio (A / B) is 1.1 or greater to less than 1.2, the width (w) is determined to be within a range of 1.0X1 to 1.25X1, where X1 is calculated by the following Equation 2: [Equation 2] Wherein, Y1 is the horizontal length of the outermost negative electrode, and Z1 is the vertical length of the outermost negative electrode.

5. The method for deactivating the outermost negative electrode according to claim 3, wherein: In the deactivation step, when the ratio (A / B) is 1.2 or greater, the width (w) is determined to be within a range of 1.0X2 to 1.5X2, wherein X2 is calculated by the following Equation 3: [Equation 3] Wherein, Y2 is the horizontal length of the outermost negative electrode, and Z2 is the vertical length of the outermost negative electrode.

6. The method for deactivating the outermost negative electrode according to claim 1, wherein: The deactivated area is formed by sticking an insulating tape or coating an insulating material.

7. The method for deactivating the outermost negative electrode according to claim 6, wherein: The insulating tape has a polyimide layer formed on one side or both sides.

8. The method for deactivating the outermost negative electrode according to claim 6, wherein: The insulating material includes epoxy compound or aluminum oxide.

9. A method for manufacturing an electrode assembly, comprising: a deactivation step of forming a deactivated region having a predetermined width (w) along an edge of one side of the first negative electrode; a step of sequentially stacking a separator, the first negative electrode having the deactivated region formed thereon, a separator, and a positive electrode to manufacture a first single unit; a step of sequentially stacking a separator, a second negative electrode on which the deactivated region is not formed, a separator, and a positive electrode to manufacture a plurality of second single cells; a step of sequentially stacking a separator, the first negative electrode having the deactivated region formed thereon, and a separator to manufacture a semi-cell; a step of sequentially stacking the plurality of second single monomers on the first single monomer to manufacture a stacked body; as well as a step of laminating the half cell on the second single cell provided at the uppermost end of the stacked body to manufacture an electrode assembly, wherein: In the deactivation step, the width (w) is determined based on a horizontal length of the first negative electrode, a vertical length of the first negative electrode, and the number of first and second single cells in the electrode assembly.

10. The method for manufacturing an electrode assembly according to claim 9, wherein: In the deactivation step, the width (w) is determined to be in the range of 0.9P2 to 1.2P2, where P2 is calculated by the following Equation 4: [Equation 4] Wherein, a2 is the horizontal length of the first negative electrode, b2 is the vertical length of the first negative electrode, and c2 is the number of the first single cell and the second single cell.

11. The method for manufacturing an electrode assembly according to claim 9, wherein: In the deactivation step, the width (w) is determined based on a ratio (A / B) of a total area (A) of one side of a plurality of negative electrodes to a total area (B) of one side of a plurality of positive electrodes in the electrode assembly.

12. The method for manufacturing an electrode assembly according to claim 11, wherein: In the deactivation step, when the ratio (A / B) is 1.1 or greater to less than 1.2, the width (w) is determined to be within a range of 1.0X3 to 1.25X3, where X3 is calculated by the following Equation 5: [Equation 5] Wherein, Y2 is the horizontal length of the first negative electrode, and Z2 is the vertical length of the first negative electrode.

13. The method for manufacturing an electrode assembly according to claim 11, wherein: In the deactivation step, when the ratio (A / B) is 1.2 or greater, the width (w) is determined to be within a range of 1.0X4 to 1.5X4, where X4 is calculated by the following Equation 6: [Equation 6] Wherein, Y2 is the horizontal length of the first negative electrode, and Z2 is the vertical length of the first negative electrode.

14. The method for manufacturing an electrode assembly according to claim 9, comprising, before the deactivation step, a determining step of determining whether deactivation of the first negative electrode in the first single cell and the half cell is necessary based on the number of the first single cell and the second single cell.

15. The method for manufacturing an electrode assembly according to claim 14, wherein: In the determining step, it is determined that the deactivation of the first negative electrode in the first single cell and the half cell is necessary when the number of the first single cell and the second single cell is less than a predetermined value.

16. The method for manufacturing an electrode assembly according to claim 14, wherein: In the determining step, it is determined that when the number of the first single cell and the second single cell is less than 15, the deactivation of the first negative electrode in the first single cell and the half cell is necessary. 17 . The method of manufacturing an electrode assembly according to claim 11 , comprising, before the deactivation step, a determining step of determining whether deactivation of the first negative electrode in the first single cell and the half cell is necessary based on the ratio (A / B).

18. The method for manufacturing an electrode assembly according to claim 17, wherein: It is determined in the determining step that the deactivation of the first negative electrode in the first single cell and the half cell is necessary when the ratio (A / B) is 1.1 or greater.

19. An electrode assembly comprising: a first single unit obtained by sequentially stacking a separator, a first negative electrode having a deactivated region having a predetermined width (w) formed thereon along an edge of one side, the separator, and a positive electrode; a plurality of second single cells stacked on the first single cell and obtained by sequentially stacking a separator, a second negative electrode, a separator, and a positive electrode; and a half cell stacked on the second single cell disposed at the uppermost end and obtained by sequentially stacking a separator, a first negative electrode having a deactivated region formed thereon, and a separator, wherein The width (w) of the deactivated region is in the range of 0.9P2 to 1.2P2, wherein P2 is calculated by the following equation 4: [Equation 4] Wherein, a2 is the horizontal length of the first negative electrode, b2 is the vertical length of the first negative electrode, and c2 is the number of the first single cell and the second single cell.

20. An electrode assembly comprising: a first single unit obtained by sequentially stacking a separator, a first negative electrode having a deactivated region having a predetermined width (w) formed thereon along an edge of one side, the separator, and a positive electrode; a plurality of second single cells stacked on the first single cell and obtained by sequentially stacking a separator, a second negative electrode, a separator, and a positive electrode; and a half cell stacked on the second single cell disposed at the uppermost end and obtained by sequentially stacking a separator, a first negative electrode having a deactivated region formed thereon, and a separator, wherein When a ratio (A / B) of a sum of areas (A) of one side of the plurality of negative electrodes to a sum of areas (B) of one side of the plurality of positive electrodes in the electrode assembly is 1.1 or greater to less than 1.2, a width (w) of the deactivation region is in a range of 1.0×3 to 1.25×3, and When a ratio (A / B) of a sum of areas (A) of one side of the plurality of negative electrodes to a sum of areas (B) of one side of the plurality of positive electrodes in the electrode assembly is 1.2 or greater, a width (w) of the deactivation region is in a range of 1.0×4 to 1.5×4; X3 and X4 are calculated by the following equations 5 and 6 respectively: [Equation 5] [Equation 6] Wherein, Y2 is the horizontal length of the first negative electrode, and Z2 is the vertical length of the first negative electrode.

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