Apparatus for manufacturing negative electrode and method for manufacturing negative electrode

Abstract

The present invention relates to an apparatus for manufacturing a negative electrode and a method for manufacturing a negative electrode, and according to the present invention, there is provided an apparatus for manufacturing a negative electrode comprising a pair of magnet plates in which an upper magnet plate and a lower magnet plate are provided above and below an X-Y plane in which the negative electrode travels in an X-axis direction, the magnet plate comprises (N + 1) magnet modules (N is greater than or equal to 1); in the magnet module, first vertical unit magnets with upward magnetic force lines, second vertical unit magnets with downward magnetic force lines, first horizontal unit magnets with leftward magnetic force lines, and second horizontal unit magnets with rightward magnetic force lines are arranged in a certain pattern in one direction of the Y axis. The magnet modules are arranged in the X-axis direction in a form parallel to the X-Y plane.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a negative electrode and an apparatus for manufacturing a negative electrode. Background Technology

[0002] Typically, the negative electrode for a secondary battery is manufactured by coating a slurry containing a negative electrode active material, a conductive agent, a binder, and a solvent onto a negative electrode current collector, followed by drying and calendering.

[0003] In the manufacturing process of the negative electrode as described above, the anisotropic negative electrode active material is mainly oriented in a horizontal direction parallel to the negative electrode current collector, and the pores formed between the negative electrode active materials are also mostly oriented in a horizontal direction. As described above, since the negative electrode active material and pores are oriented in a horizontal direction, lithium ions move through the horizontally oriented pores during the charging or discharging process of the secondary battery.

[0004] In addition, in recent years, with the increasing demand for rechargeable batteries, the demand for high performance and long service life of rechargeable batteries is also increasing, and thus, increasing the load on the negative electrode to achieve high capacity has become a trend.

[0005] As mentioned above, with the increasing capacity of batteries, the demand for improving the fast charging performance of batteries is continuously increasing. However, as mentioned above, when the pores in the negative electrode are oriented horizontally, the load on the negative electrode increases while the migration distance of lithium ions increases significantly. This increase in migration distance leads to an increase in resistance during the charging process, thereby increasing the charge and discharge time.

[0006] In particular, when charged or discharged at a high C-rate, lithium salts (Li-plating) are deposited on the surface of the negative electrode. With repeated charge-discharge cycles, the battery capacity is reduced, and problems that compromise battery safety occur.

[0007] Graphite used as a negative electrode active material typically has a spherical shape with a certain degree of anisotropy. When the graphite is oriented in a direction perpendicular to the current collector, the diffusion of lithium ions into the negative electrode can be increased, thereby reducing resistance and, in particular, improving fast charging performance.

[0008] One method for orienting graphite, a diamagnetic material, is to apply a magnetic field perpendicular to the negative electrode current collector using a permanent magnet just before the negative electrode slurry coated on the negative electrode current collector is dried. The stronger the magnetic field, the higher the perpendicular orientation of the negative electrode active material and the pores can be ensured within the same magnetic field application time. Summary of the Invention

[0009] (a) Technical problems to be solved

[0010] As described above, the object of the present invention is to provide a negative electrode that can improve battery performance by ensuring sufficient vertical orientation of the negative electrode active material in a short time, and a negative electrode manufacturing apparatus that can manufacture the negative electrode.

[0011] Furthermore, the present invention aims to provide a method for manufacturing a negative electrode using the negative electrode manufacturing apparatus described above.

[0012] Furthermore, the present invention aims to provide a negative electrode having the characteristic that the orientation of the negative electrode active material relative to the negative electrode current collector is uniform throughout the entire negative electrode.

[0013] (II) Technical Solution

[0014] One specific embodiment of the present invention provides an apparatus for manufacturing a negative electrode. The apparatus may include a pair of magnet plates, an upper magnet plate and a lower magnet plate, disposed above and below the negative electrode in an XY plane traveling along the X-axis. Each magnet plate may include (N+1) (N≥1) magnet modules. The magnet modules contain a first vertical unit magnet with its magnetic field lines pointing upwards, a second vertical unit magnet with its magnetic field lines pointing downwards, a first horizontal unit magnet with its magnetic field lines pointing to the left, and a second horizontal unit magnet with its magnetic field lines pointing to the right. The magnet modules are arranged in a certain pattern along one direction of the Y-axis. They can be arranged parallel to the XY plane along the X-axis. When the Y-coordinate of the first unit magnet of the first magnet module is set to 0, the absolute value of the Y-coordinate of the first unit magnet of the (N+1)th magnet module can be N×d. The first unit magnet of the (N+1)th magnet module can be of the same type as the first unit magnet of the Nth magnet module. The first unit magnet of the (N+1)th magnet module can be located at the origin (O) of the Nth magnet module. N The position is located at a point where a straight line parallel to the X-axis moves a distance d along one direction of the Y-axis, where the distance d is less than the width of the unit magnet.

[0015] The distance d can be n times the value obtained according to any one of equations (1) to (5).

[0016]

[0017]

[0018]

[0019]

[0020]

[0021] Where n is a natural number greater than or equal to 1, LY1 is the length of the first vertical unit magnet in the Y-axis direction, LY3 is the length of the second vertical unit magnet in the Y-axis direction, LY2 is the length of the first horizontal unit magnet in the Y-axis direction, LY4 is the length of the second horizontal unit magnet in the Y-axis direction, and N+1 is the number of magnet modules that make up the magnet plate.

[0022] The magnet module can have a unit magnet arrangement mode in which the direction of the magnetic field lines changes by 90 degrees each time along the Y-axis.

[0023] The (N+1)th magnet module may have the same unit magnet arrangement pattern as the Nth magnet module.

[0024] The last magnet module included in the magnet plate can be set at a position that is moved 2n unit magnets relative to the first magnet module in the Y-axis direction, where n can be a natural number greater than or equal to 1.

[0025] The magnet module may be equipped with horizontal unit magnets at both ends.

[0026] The two horizontal unit magnets located at the two side ends can be the same or different from each other.

[0027] The magnets with opposite polarities in the upper magnet plate and the lower magnet plate can face each other.

[0028] The magnetic force of the magnet plate can change in the Y-axis direction.

[0029] The lengths (LX) of the unit magnets included in a magnet module within the magnet plate can be the same in the X-axis direction.

[0030] The magnetic field lines and magnetic force of the same unit magnets included in the magnet plate can be the same.

[0031] The magnetic force of the unit magnets included in the magnet plate can be the same.

[0032] The thicknesses of the vertical and horizontal unit magnets included in the magnet plate can be the same or different from each other.

[0033] The magnet plate may include three or more long magnet modules and at least one short magnet module. The length of the long magnet module is the same as the length of the magnet plate in the Y-axis direction, and the length of the short magnet module is shorter than the length of the magnet plate in the Y-axis direction. The two ends of the long magnet module may be aligned with a straight line parallel to the X-axis of the magnet plate.

[0034] The length difference between the short magnet module and the length of the magnet plate in the Y-axis direction can be less than or equal to the length of the unit magnet.

[0035] The two ends of the short magnet module can be separated from the long magnet module by a straight line.

[0036] Vertical unit magnets can be provided at both ends of the short magnet module.

[0037] The vertical unit magnets located at the two side ends can be of the same type or different types.

[0038] At least one of the long magnet modules may have partial vertical unit magnets at both ends, and the length of the partial vertical unit magnets may be less than the length of the first vertical unit magnet or the second vertical unit magnet.

[0039] The lengths of the vertical unit magnets located at the two side ends can be the same or different from each other.

[0040] The total length of each of the vertical unit magnets located at the two side ends can be equal to the length of either the first vertical unit magnet or the second vertical unit magnet.

[0041] Another specific embodiment of the present invention provides a method for manufacturing a negative electrode, the method comprising the following steps: a coating step, coating a negative electrode mixture containing a negative electrode active material onto at least one side of a negative electrode current collector; and a magnetic field step, wherein, under the applied magnetic field, the negative electrode current collector coated with the negative electrode mixture travels between an upper magnet plate and a lower magnet plate, wherein the magnetic field is applied by any of the above-described apparatus for manufacturing a negative electrode.

[0042] The method may further include a drying step of drying the negative electrode mixture, which may be performed during or after the step of applying the magnetic field.

[0043] The magnetic field can be applied in a direction perpendicular to the negative electrode current collector.

[0044] The magnetic force of the magnetic field can change along both the X and Y axes.

[0045] The magnetic field in the magnet module can repeatedly increase and decrease the magnetic force along the Y-axis direction.

[0046] The magnetic field in the magnet module can have a sine wave depending on the position of the magnetic force in the Y-axis direction.

[0047] The magnetic field can be applied for more than 1 second.

[0048] The negative electrode mixture can have a viscosity below 150,000 cp (at 25°C, 0.1 s⁻¹). -1 (Measured at the shear rate).

[0049] (III) Beneficial Effects

[0050] According to the present invention, the magnetic force can be maximized, thereby improving the vertical orientation of the negative electrode active material even in a short electrode travel time.

[0051] According to the present invention, although a magnetic field is applied during the manufacturing process of the negative electrode, the negative electrode still has a uniform orientation in the direction of travel and the width direction, thus further improving the cell charging performance of the battery. Attached Figure Description

[0052] Figure 1 A diagram illustrating a conventionally arranged array of magnet plates used to apply a magnetic field.

[0053] Figure 2 The diagram illustrates a magnet plate with vertical and horizontal unit magnets arranged such that the direction of the magnetic field lines is rotated 90 degrees each time.

[0054] Figure 3 The diagram schematically illustrates an example of a vertical unit magnet (a) and a horizontal unit magnet (b), where (a) shows a vertical unit magnet with the magnetic field lines pointing downwards and (b) shows a horizontal unit magnet with the magnetic field lines pointing to the right.

[0055] Figure 4 To conceptually demonstrate having Figure 2 A diagram showing the changes in the magnetic force and direction of the magnetic field applied by a magnetic plate with arranged magnets.

[0056] Figure 5 To illustrate, it will have Figure 2 The diagram shows the magnetic force and the direction of magnetic field lines when the magnet plate, arranged with magnets, is applied to both sides of the plane of negative pole travel.

[0057] Figure 6 A diagram illustrating a magnet plate according to one embodiment.

[0058] Figure 7 A diagram illustrating a magnet plate according to another embodiment.

[0059] Figure 8 A diagram illustrating a magnet plate according to another embodiment.

[0060] Figure 9 A diagram illustrating a magnet plate according to another embodiment.

[0061] Figure 10 To illustrate the use of the application Figures 6 to 9 A diagram showing the intensity of the magnetic force applied according to the width direction position of the negative pole during the manufacturing of the negative pole of any type of magnet plate.

[0062] Figure 11 The diagram schematically illustrates one of the magnet plates positioned above and below the XY plane traveling along the X-axis direction at the negative pole, showing a magnet plate that creates a magnetic field that periodically changes in the X-axis direction by arranging vertical and horizontal unit magnets such that the direction of the magnetic field lines changes by 90 degrees each time in the X-axis direction.

[0063] Figure 12 The diagram schematically illustrates one of the magnet plates positioned above and below the XY plane traveling along the X-axis direction at the negative pole, showing a magnet plate that creates a periodically changing magnetic field by arranging vertical and horizontal unit magnets such that the direction of the magnetic field lines changes by 90 degrees each time in the Y-axis direction.

[0064] Figure 13 To illustrate the preferred orientation (P / O) of the negative electrode active material measured by XRD at 10 points at 10 mm intervals in the width direction of the negative electrode for each negative electrode manufactured in Examples 1 to 2 and Comparative Examples 1 to 4.

[0065] Explanation of reference numerals in the attached figures:

[0066] 1: First vertical unit magnet

[0067] 2: First horizontal unit magnet

[0068] 3: Second vertical unit magnet

[0069] 4: Second horizontal unit magnet

[0070] 8: Short magnet module

[0071] 9: Long magnet module

[0072] 10: Magnet Module

[0073] 10 N+1 The (N+1)th magnet module

[0074] 11, 13: Magnet plate

[0075] 15: Travel Area

[0076] 16: Space

[0077] 17: Spare magnets

[0078] 18, 19: Space

[0079] O N+1 The position (origin) is located to the lower left of the (N+1)th unit magnet. Detailed Implementation

[0080] In recent years, in order to improve battery performance by shortening the movement path of lithium ions, a method is being used to manufacture negative electrodes by applying a magnetic field with a permanent magnet and then moving the negative electrode mixture slurry onto the negative electrode current collector into the magnetic field.

[0081] Typically, permanent magnets are used to apply a magnetic field, which can be achieved using a magnetic plate with individual magnets arranged in a row. The magnetic plate can have, for example, [missing information - likely a specific feature or characteristic]. Figure 1 The arrangement of magnets is shown. Specifically, as... Figure 1 As shown, a magnet plate can be constructed with the following magnet arrangement, in which multiple unit magnets are arranged in the same manner, such that the magnetic force is directed in a certain direction. When using a magnet plate with such... Figure 1 When the magnets are arranged in a magnetic plate as shown, they can provide a maximum magnetic force of approximately 4000 Gauss (G).

[0082] To improve the productivity of the negative electrode, the process of coating and drying the negative electrode mixture slurry onto the negative electrode current collector is gradually accelerated at high speed. Therefore, the time for applying a magnetic field during the manufacturing process of the negative electrode is limited to within a few seconds. Thus, when using... Figure 1 When using a magnet plate as shown, due to the relatively small magnetic force of the magnetic field, it may be difficult to ensure a sufficient degree of orientation of the negative pole in a short period of time.

[0083] At this point, in order to maximize the magnetic force of the magnetic field, one can use, for example... Figure 2 The magnet plate with magnets arranged as shown.

[0084] Specifically, such as Figure 2 As shown, a magnet plate with the following arrangement can be used, in which neodymium (Nd) permanent magnets including N poles and S poles are used as unit magnets and the unit magnets are arranged such that the direction of the N pole and S pole of each unit magnet, that is, the direction of the magnetic field lines, changes by 90 degrees each time in a certain direction such as clockwise or counterclockwise, so that the magnetic force on one side can be maximized.

[0085] More specifically, such as Figure 2 As shown, from left to right, the first vertical unit magnet 1 with the magnetic field lines pointing upward, the first horizontal unit magnet 2 with the magnetic field lines pointing to the left, the second vertical unit magnet 3 with the magnetic field lines pointing downward, and the second horizontal unit magnet 4 with the magnetic field lines pointing to the right are arranged in sequence, so as to form a magnet plate in which the direction of the magnetic field lines changes by 90 degrees each time in a counterclockwise direction.

[0086] Figure 3 An example of the second vertical unit magnet 3 and the second horizontal unit magnet 4 is schematically shown. Figure 3 The first vertical unit magnet 1 and the first horizontal unit magnet 2 can be easily understood. At this point, as... Figure 3 As shown, when the negative pole travels in the X-axis direction, the length of the unit magnet in the X-axis direction is set as LX, the length in the Y-axis direction is set as LY, and the thickness is set as D.

[0087] As described Figure 2 The magnetic field lines generated by the arrangement of the magnet plates shown are formed in both the vertical and horizontal directions, thus creating a magnetic field with the following characteristics: Figure 4 The magnetic field shows the direction of the magnetic force and magnetic field lines. This is achieved through methods such as... Figure 2 The magnet plate shown, which arranges vertical and horizontal unit magnets in such a way that the direction of the magnetic field lines is rotated 90 degrees each time, can increase the magnetic force.

[0088] For example, when using such Figure 2 The direction of the magnetic force shown changes each time the magnet plate is rotated 90 degrees, although... Figure 4 The magnitude of the magnetic force shown varies periodically, but a much larger magnetic force of up to 8000G can be generated. Therefore, if the negative pole is placed in an environment with a magnetic field similar to... Figure 2 When the magnetic field generated by the magnet plate arranged as shown is traveled within the magnetic field region, it can orient the negative electrode active material in the negative electrode mixture layer.

[0089] When using, having, as Figure 2 When a magnet plate with the magnets arranged as shown is formed, the positions of the N and S poles of the unit magnets constituting the magnet plate change, which causes the directions of the magnetic field lines to change in both the vertical and horizontal directions. Therefore, as shown... Figure 4 The diagram shows horizontal magnetic field lines. If the negative electrode is made to travel within a magnetic field region with the horizontal magnetic field lines as described above, the horizontal magnetic field lines will adversely affect the orientation of the negative electrode active material, thus potentially limiting its ability to improve the orientation of the negative electrode.

[0090] Using such Figure 2 When the magnetic plates arranged in the magnetic field are oriented to the negative electrode active material, when the direction of travel of the negative electrode is parallel to the X-axis, the orientation characteristics can be at least partially periodically varied in the width direction of the negative electrode, i.e., the Y-axis direction, and the orientation can be relatively uniform in the X-axis direction, which is the direction of travel.

[0091] Additionally, when having such Figure 2When the magnet plates arranged as shown are placed on both the upper and lower sides of the moving path of the negative electrode, the horizontal magnetic field lines described above can be removed, so that only the vertical magnetic field lines exist in the magnetic field, thus further improving the orientation of the negative electrode active material. Figure 5 This situation is illustrated schematically in (a).

[0092] like Figure 5 As shown in (a), a pair of magnet plates (11, 13) can be provided on the upper and lower sides of the negative pole's travel path. The magnet plates (11, 13) contain a first vertical unit magnet 1, a second vertical unit magnet 3, a first horizontal unit magnet 2, and a second horizontal unit magnet 4 arranged such that the direction of the magnetic field lines changes by 90 degrees each time. In this case, the magnet plates (11, 13) on the upper and lower sides can be arranged such that magnets with opposite polarities face each other.

[0093] For example, such as Figure 5 As shown in (a), when the first vertical unit magnet 1 with the polarity of S pole is set on the lower magnet plate 13 facing the negative pole travel surface, a second vertical unit magnet 3 with the N pole facing the negative pole travel surface can be set on the upper magnet plate 11.

[0094] By such Figure 5 As shown in (a), a pair of magnet plates (11, 13) are arranged on the upper and lower sides of the negative electrode traveling surface. This can reduce the magnetic force on the outside of the traveling surface, i.e., below the lower magnet plate 13 and above the upper magnet plate 11, and increase the magnetic force between the traveling surface of the negative electrode, i.e., between the upper magnet plate 11 and the lower magnet plate 13, thereby improving the orientation of the negative electrode.

[0095] In addition, such as Figure 5 As schematically shown in diagrams (a) and (b), the magnetic force repeatedly increases and decreases along the Y-axis, resulting in a periodic change. Specifically, in Figure 5 In (a), the magnitude of the magnetic force between the upper magnet plate 11 and the lower magnet plate 13 is represented by the thickness of the solid line. The magnetic force repeatedly increases and decreases, and the change in magnetic force according to the arrangement of the magnet plates is shown. Figure 5 In (b).

[0096] In addition, from Figure 5 As shown in (a) and (b), the magnetic force periodically increases and decreases repeatedly in the width direction of the magnet plate. However, since the magnetic field lines in the horizontal direction between the upper magnet plate 11 and the lower magnet plate 13 are removed, the magnetic field lines in the vertical direction take effect. Therefore, the magnetic field applied according to the present invention can be applied in a direction perpendicular to the negative electrode current collector.

[0097] In this invention, as described above, by setting a pair of magnet plates (the pair of magnet plates uses vertical unit magnets and horizontal unit magnets and the unit magnets are arranged in such a way that the direction of the magnetic field lines rotates by 90 degrees each time) on the upper and lower sides of the negative electrode traveling surface and applying a magnetic field to make the negative electrode travel, a negative electrode in which the negative electrode active material in the negative electrode mixture layer is oriented in a direction perpendicular to the negative electrode current collector can be manufactured.

[0098] More specifically, the present invention provides an apparatus for manufacturing a negative electrode, the apparatus comprising a pair of magnet plates including an upper magnet plate and a lower magnet plate, wherein the pair of magnet plates are formed by the following method: when the direction of travel of the negative electrode is set as the X-axis direction and the plane of travel of the negative electrode is set as the XY plane, vertical unit magnets and horizontal unit magnets are arranged above and below the XY plane along the Y-axis direction to form a pair of magnet plates including an upper magnet plate and a lower magnet plate.

[0099] At this time, the upper magnet plate and the lower magnet plate may include vertical unit magnets and horizontal unit magnets. Specifically, the vertical unit magnets may include a first vertical unit magnet with upward magnetic field lines and a second vertical unit magnet with downward magnetic field lines. The horizontal unit magnets may include a first horizontal unit magnet with left-facing magnetic field lines and a second horizontal unit magnet with right-facing magnetic field lines.

[0100] While there are no particular restrictions, the magnetic field lines and magnetic forces of unit magnets of the same type included in the magnet plate can be the same or different. Furthermore, even if the unit magnets included in the magnet plate are not of the same type, their magnetic forces can be identical.

[0101] More specifically, the magnet plate includes magnet modules that use multiple of the above-mentioned two types of vertical unit magnets and two types of horizontal unit magnets arranged in a certain pattern in one direction toward the Y-axis.

[0102] The magnet module can be formed using multiple unit magnets, specifically, such as Figure 5 As shown in (a), the unit magnet arrangement can be configured such that the direction of the magnetic field lines changes by 90 degrees each time along the Y-axis. That is, the magnet module can have substantially the same cross-sectional shape as the magnet plate described above. In this case, Figure 5 Only a portion of the arrangement of the aforementioned unit magnets in one magnet module is shown, but the arrangement of the first vertical unit magnet 1, the first horizontal unit magnet 2, the second vertical unit magnet 3, and the second horizontal unit magnet 4 can be repeated.

[0103] Specifically, a magnet plate can be manufactured by arranging the above-mentioned multiple magnet modules along the X-axis direction. The magnet plate obtained by arranging the magnet modules can have a plane relative to the negative pole travel surface.

[0104] There is no particular limitation on the number of magnet modules used to manufacture the magnet plate; it can be N+1. In this case, N can be a natural number greater than 1.

[0105] The magnet module can be formed by using multiple unit magnets in the Y-axis direction, and a magnet plate can be manufactured using multiple magnet modules as described above. In this case, the magnet modules constituting the magnet plate can have the same form. That is, the unit magnets can be arranged in the same pattern, and the (N+1)th magnet module (the (N+1)th magnet module) can have the same unit magnet arrangement pattern as the Nth magnet module (the Nth magnet module).

[0106] The magnet modules can be arranged in a row along the X-axis, but in this invention, when the magnet modules move along the X-axis, the magnet modules can be positioned at a position that moves a certain distance d along a certain direction along the Y-axis.

[0107] That is, the first unit magnet (first unit magnet) included in the (N+1)th magnet module can be of the same type as the first unit magnet included in the Nth magnet module, and the first unit magnet (first unit magnet) included in the (N+1)th magnet module can be located at the origin (O) passing through the Nth magnet module. N The position is located at a point where a straight line parallel to the X-axis moves a distance d along one direction of the Y-axis, where the distance d is less than the width of the unit magnet.

[0108] The distance d is not particularly limited, but it can be less than the width of the unit magnet used in this invention; specifically, it can be less than the length of the unit magnet in the Y-axis direction within the magnet plate. In this case, when the widths of the unit magnets used to compose the magnet module are different from each other, the width of the unit magnet can be the minimum width. More specifically, the distance d can be less than 3 / 4, 2 / 3, 1 / 2, 1 / 3, or 1 / 4 of the width of the unit magnet.

[0109] Figure 6 This situation is illustrated schematically. Figure 6 This is a schematic diagram illustrating an example of a magnet plate according to a specific embodiment of the present invention, as shown in the figure. Figure 6 As shown, when the first magnet module 10 is located... 1 The origin O is set to the lower left position of the first unit magnet on the left. 1 At that time, the second magnet module 10 located in the second position 2 Origin2 It can be located relative to the origin O. 1 The X-axis moves a distance d along a straight line parallel to the position on the Y-axis. Furthermore, the third magnet module 10 is located in the third position. 3 Origin 3 It can be located relative to the origin O passing through the second magnet module. 2 The line parallel to the X-axis moves a distance d in the Y-axis direction to a position on the parallel line. If we represent this in coordinates, when the first magnet module 10 is... 1 When the Y-coordinate of the first unit magnet is set to 0, the Y-coordinate of the first unit magnet of the second magnet module can be d, the Y-coordinate of the first unit magnet of the third magnet module can be 2×d, and the Y-coordinate of the first unit magnet of the (N+1)th magnet module can be N×d.

[0110] As mentioned above, when using each magnet module, such as Figure 6 As shown, each magnet module can be set with the origin, which is set at a position where it moves a predetermined distance d in the Y-axis direction each time, as a reference. By using magnet plates that are set at adjacent magnet modules at the moving positions relative to a magnet module as described above, the change in the orientation degree of the negative electrode active material caused by the change in magnetic force appearing in a magnet module can be canceled out, thus obtaining a negative electrode with a uniform orientation degree throughout the entire negative electrode. Furthermore, by using the magnet plates as described above, the amount of magnetic force applied to a specific position in the width direction of the negative electrode can be superimposed on each other, thus enhancing the overall magnetic force strength and further improving the orientation degree of the negative electrode.

[0111] Regarding the direction of the aforementioned positional movement, the figure shows an example of moving the position in the positive Y-axis direction with the X-axis as the reference, but it can be easily understood that movement is also possible in the negative Y-axis direction.

[0112] In the magnet module, the orientation of the negative pole is more significantly influenced by the unit magnet that provides high magnetic force. That is, the influence of the vertical unit magnet can be considered substantial. Therefore, the distance d can be determined based on the distance between the position of the peak magnetic force when the magnetic force changes periodically in a magnet module and the position of the next peak magnetic force (the distance between the positions of maximum magnetic force). In other words, the distance d can be determined based on the amplitude of a magnetic force change cycle, and also based on the distance between the centers of two vertical magnets in the horizontal direction of the magnet module.

[0113] When the length of the first vertical unit magnet 1 in the Y-axis direction is set as LY1, the length of the second vertical unit magnet 3 in the Y-axis direction is set as LY3, the length of the first horizontal unit magnet 2 in the Y-axis direction is set as LY2, and the length of the second horizontal unit magnet 4 in the Y-axis direction is set as LY4, the distance d can be determined according to the formula [LY1 / 2+(LY2+LY4) / 2+LY3 / 2]. For example, the distance d can be a natural number (n) times the value obtained by dividing the above formula by the number of magnet modules N+1. In this case, the natural number n is not particularly limited, and the natural number n can be 1, 2, 3, 4, or larger.

[0114] The distance d can be expressed as a natural number (n) times the value obtained according to any one of the following equations (1) to (5).

[0115]

[0116] Specifically, as described above, Equation (1) is based on the distance between the positions of maximum magnetic force. Equation (1) indicates the case where the lengths of the first vertical unit magnet 1 and the second vertical unit magnet 3 are different in the Y-axis direction and the lengths of the first horizontal unit magnet 2 and the second horizontal unit magnet 4 are different in the Y-axis direction. Equations (2) and (3) indicate the case where the lengths of the first vertical unit magnet 1 and the second vertical unit magnet 3 are different in the Y-axis direction and the lengths of the first horizontal unit magnet 2 and the second horizontal unit magnet 4 are the same in the Y-axis direction. Equations (4) and (5) indicate the case where the lengths of the first vertical unit magnet 1 and the second vertical unit magnet 3 are the same in the Y-axis direction and the lengths of the first horizontal unit magnet 2 and the second horizontal unit magnet 4 are the same in the Y-axis direction.

[0117] When the value of the distance d is equal to any of the values ​​obtained according to the above formula (i.e., 1 times), the first unit magnet of the last magnet module (the (N+1)th magnet module) can be positioned at a location where it has moved a distance of an even number of unit magnets in the Y-axis direction relative to the first unit magnet of the first magnet module, parallel to the X-axis. Alternatively, when the value of the distance d is an integer multiple of n of the value obtained according to any of the above formulas, the first unit magnet of the (N+1)th magnet module, being the last magnet module, can be positioned at a location where it has moved a distance of 2n unit magnets in the Y-axis direction relative to the first unit magnet of the first magnet module, parallel to the X-axis.

[0118] Figure 6 The image shows a magnet plate comprising a total of 10 magnet modules, with an example shown below: The first magnet module 10 is located relative to the first one. 1 The Y-coordinate of the first magnet unit, the last 10th magnet module 10 10The Y-coordinate of the first unit magnet is set at a position two unit magnets away along the Y-axis, i.e., the first magnet module 10 is located in the first position. 1 The Y-coordinate of the first magnet unit and the last 10th magnet module 10 10 The Y-coordinate values ​​of the first unit magnet differ by 2 unit magnets. Therefore, it can be known that the distance d is 1 times the value obtained from any of the above equations (1) to (5).

[0119] In the magnet plate of the present invention, such as Figure 6 As shown, each magnet module can be used only in one direction of the first unit magnet (the first direction, Figure 6 In the positive Y-axis direction, the unit magnets are arranged sequentially in a predetermined pattern. In this case, the unit magnets may not be arranged in the opposite direction to the first direction (the second direction). Figure 6 (in the negative Y-axis direction).

[0120] When a magnet plate having the arrangement of magnet modules as described above is used to orient the negative pole, such as Figure 6 As shown, the negative electrode to be oriented can be in the 10th magnet module (10 N+1 =10 10 Unit 1 magnet and Unit 1 magnet module 10 1 The region between the last unit magnets travels, and this region may be referred to as travel region 15, but is not limited thereto.

[0121] For the magnet plate, in one specific embodiment, such as Figure 6 As shown, horizontal unit magnets can be provided at both ends of each magnet module constituting the magnet plate, but are not limited to this. (Refer to...) Figure 4 and Figure 5 The magnetic forces of the horizontal unit magnets located at both ends of the vertical unit magnet can be superimposed on the vertical unit magnet, thereby providing the effect of displaying the maximum magnetic force in the vertical unit magnet. Therefore, by setting horizontal unit magnets on both sides of the magnet module, the magnetic force of the vertical unit magnets at adjacent positions can be maximized, and the deviation of magnetic force caused by the position of the magnet module can be minimized.

[0122] As another specific implementation, the magnet plate may have the following characteristics: Figure 7 The pattern is schematically shown in the diagram. That is, the... Figure 6 The magnet plate can be deformed into such a shape as Figure 7 The illustrated magnet plate.

[0123] Figure 7 The magnet plate shown is composed of different materials. Figure 6The magnet board shown is arranged in the order of the magnet modules. Specifically, Figure 7 The magnet plate is to change Figure 6 The magnet plate is positioned at the locations of the first to fifth magnet modules and the sixth to tenth magnet modules of the magnet plate. This magnet plate is for... Figure 6 The 6th to 10th magnet modules of the magnet plate are used as Figure 7 The first to fifth magnet modules of the magnet plate and Figure 6 Magnet modules 1 through 5 are used as Figure 7 The magnet plate is composed of the 6th to 10th magnet modules of the magnet plate.

[0124] The deformation of the magnet plate is not limited to Figure 7 The form shown can be transformed into various forms.

[0125] As another specific implementation, the magnet plate may have the following characteristics: Figure 8 The pattern is schematically shown in the diagram. That is, the... Figure 6 The magnet plate can be deformed into such a shape as Figure 8 The illustrated magnet plate.

[0126] Figure 8 The magnet plate shown is constructed by changing the composition of the magnet plate. Figure 6 A magnet plate is formed by setting up magnet modules in a magnet plate and adding or removing some unit magnets according to the travel area of ​​the negative pole. Specifically, Figure 8 The magnet plate is constructed as follows: [Change] Figure 6 The positions of the first to fifth magnet modules and the sixth to tenth magnet modules of the magnet plate will be... Figure 6 The 6th to 10th magnet modules of the magnet plate are used as Figure 8 The first to fifth magnet modules of the magnet plate will... Figure 6 Magnet modules 1 through 5 are used as Figure 8 The 6th to 10th magnet modules of the magnet plate are removed, and the unit magnets located at one end of the 2nd to 5th magnet modules are removed respectively. Specifically, the 1st vertical unit magnet and the 2nd vertical unit magnet are removed respectively.

[0127] Figure 8An example of removing a unit magnet from one side of a magnet module is shown, but deformation can be achieved by adding unit magnets, and by adding or removing unit magnets from the other side or both sides. Furthermore, deformation can be achieved by adding unit magnets to a portion of the magnet module and removing unit magnets from other portions. In this case, the two horizontal unit magnets located at the aforementioned two side ends can be identical or different from each other. As another specific embodiment, the magnet plate of the present invention can be [missing information - likely a specific feature or design]. Figure 6 The same magnet module pattern and magnet plate at a distance d, and can be as follows Figure 9 The square magnet plate shown.

[0128] For example, the magnet plate can be a plate with a magnet plate that has ... Figure 9 A square magnet plate, the length from the origin of the first magnet module to the end (terminus) of the last unit magnet of the first magnet module. In this case, refer to... Figure 6 It can be seen that the left side of the second magnet module to the (N+1)th magnet module has a space 16 without a magnet, and the right side contains a spare magnet 17. Therefore, as described... Figure 9 The square magnet plate shown can be, for example, by... Figure 6 The spare magnets existing on the right side of the traveling area in the magnet plate are arranged in the space area on the left side and are formed by changing the pattern of each magnet module in a way that makes the pattern consistent.

[0129] Specifically, the magnet plate can be a magnet plate in which magnets are arranged in the first and second directions of the first unit magnet of each magnet module other than the first magnet module. That is, it can be as follows: Figure 9 The square magnet plate shown above saves space required for setting up equipment to apply the magnetic field and reduces the need for strict control over the travel accuracy of the negative pole as it travels on the magnet plate.

[0130] The magnets arranged in the second direction can be configured using magnets that maintain the magnet arrangement pattern applied to each magnet module. Therefore, the magnets arranged in the second direction can be the first vertical unit magnet and the second vertical unit magnet, as well as the first horizontal unit magnet and the second horizontal unit magnet used in this invention. In the second direction, unit magnets that maintain the aforementioned magnet arrangement pattern can be used, and unit magnets with a length equal to the distance from the X-axis passing through the origin of the first magnet module can be configured.

[0131] At this point, the "first unit magnet" in the (N+1)th magnet module does not simply refer to any one of the two side ends of the (N+1)th magnet module, but rather refers to a unit magnet of the same type as the first unit magnet of the Nth magnet module, located at the origin (O) of the Nth magnet module. N The unit magnet is located at a position where it has moved a linear distance d parallel to the X-axis. For example, in Figure 9 In the second magnet module, the first unit magnet can be a first horizontal unit magnet 2 of the same type as the first unit magnet of the first magnet module, and can be located at the origin O of the first magnet module. 1 The unit magnet is moved a distance d along the positive Y-axis.

[0132] like Figure 9 As shown, the magnet plate may have three or more long magnet modules with the same length as the Y-axis of the magnet plate, and the two side ends of the long magnet modules may be aligned with a straight line parallel to the X-axis of the magnet plate.

[0133] The magnet plate may include at least one long magnet module with partially vertical unit magnets disposed at both ends. As described above, in... Figure 6 In the magnet plate shown, by arranging spare magnets in space in a manner aligned with a straight line parallel to the X-axis, the two side ends of a portion of the long magnet module may include a portion of the vertical unit magnet that has been cut from the unit magnet.

[0134] The partial vertical unit magnet may be a part of the first vertical unit magnet or the second vertical unit magnet, and the partial vertical unit magnets disposed at the two side ends may be of the same type or different types.

[0135] The length of each of the vertical unit magnets located at the two side ends can be less than the length of the first vertical unit magnet or the second vertical unit magnet. For example, the length difference of the partial vertical unit magnets located at the two side ends of the magnet module can be an integer multiple of 1 or more of the distance d.

[0136] Furthermore, the lengths of the vertical unit magnets disposed at the two side ends can be the same or different from each other. For example, the length difference between the two vertical unit magnets disposed at the two side ends in a magnet module can be an integer multiple of the distance d. When the lengths of the two vertical unit magnets are the same, their length difference is 0. When either of the two vertical unit magnets is longer, their length difference can be d, 2d, 3d, etc.

[0137] In addition, the total length of each portion of the vertical unit magnet provided at the two side ends may be equal to the length of the first vertical unit magnet or the second vertical unit magnet, but is not limited to this.

[0138] like Figure 7 As shown, the unit magnets located at the two side ends of the first and tenth magnet modules in the magnet plate are the first horizontal unit magnet 2 and the first vertical unit magnet 1, respectively, and they have the same size as the unit magnets of the same type located in the same module.

[0139] In addition, as described Figure 8 As shown, with the second to fifth magnet modules positioned at a distance d, a portion of the first vertical unit magnet and a portion of the second vertical unit magnet can be located at opposite ends of each magnet module. In this case, when the two portions of the first vertical unit magnet located at opposite ends of a magnet module are combined, their size can be the same as that of a complete vertical unit magnet. That is, the partial unit magnets located at opposite ends can have the same size as a single, separate unit magnet.

[0140] The vertical unit magnets located at the two side ends can be the same or different from each other. Specifically, as shown... Figure 8 As shown, a portion of the first vertical unit magnet can be located at the first side end, and a portion of the second vertical unit magnet can be located at the second side end. Furthermore, although not shown in the figure, vertical unit magnets of the same type can be located at the first side end and the second side end, respectively.

[0141] Additionally, the magnet plate may include at least one magnet module that omits at least one of the first or second horizontal unit magnets compared to the first magnet module. Therefore, the length of at least one magnet module constituting the magnet plate may be less than the length of the magnet plate in the Y-axis direction. For example, the magnet plate may include at least one short magnet module whose length is shorter than the length of the magnet plate in the Y-axis direction. The two ends of the short magnet module may be spaced apart from the X-axis of the magnet plate (i.e., the straight line aligned with the long magnet module).

[0142] The omitted unit magnet mentioned above can be a single unit magnet. The omitted unit magnet can be a horizontal unit magnet, specifically, a first horizontal unit magnet or a second horizontal unit magnet. Therefore, the two side ends of the short magnet module having the omitted unit magnet can be provided with vertical unit magnets, and the vertical unit magnets provided at the two side ends can be of the same type or different types.

[0143] The difference between the length of the short magnet module and the length of the magnet plate along the Y-axis (specifically, the length of the long magnet module) can be less than the length of the unit magnet. The length of the magnet plate along the Y-axis can be the length of the long magnet module.

[0144] At this time, the two side ends of the short magnet module can be separated from the straight line aligned with the long magnet module, and the distance between the two side ends of the short magnet module and the straight line aligned with the long magnet module can be an integer multiple of the distance d. The above-mentioned separation distances of the two side ends can be the same or different. In addition, the sum of the two separation distances of the two side ends can be equal to the length of a unit magnet.

[0145] like Figure 9 As shown, unlike magnet modules 2 through 5, magnet modules 6 through 9 may not include partial unit magnets at their two side ends. Figure 9 In the sixth to ninth magnet modules, depending on the module's position, when following the magnet module's pattern, a portion of the second horizontal unit magnet is sequentially arranged at each of the two side ends. However, when a portion of the aforementioned horizontal unit magnet is arranged, this portion is not part of the horizontal unit magnet used in the magnet module; rather, it can be considered an independent unit magnet with a different size. Therefore, the magnet module does not necessarily have a fixed pattern. When a portion of the horizontal unit magnet is located at both side ends of the magnet module, this horizontal unit magnet can be omitted.

[0146] Therefore, the magnet plate according to a specific embodiment of the present invention can have the following characteristics: Figure 9 The spaces (18, 19) without magnets are shown. These spaces (18, 19) may be located at a portion of the two side ends of the magnet plate in the Y-axis direction, and may also be located at the two ends of a magnet module.

[0147] The length of the space (18, 19) located at one side end of the magnet module can be less than the length of a unit magnet in the Y-axis direction, and the sum of the lengths of the spaces (18, 19) located at each side end can be equal to the length of a unit magnet. In this case, the unit magnet can represent a predetermined magnet module located at the side end according to the pattern of the magnet module.

[0148] When using, having, as Figure 9 When the magnet plate of the magnet module arrangement shown in the exemplary diagram is oriented to the negative pole, the negative pole to be oriented can travel in the following travel area, which is the area between the innermost side of the space 18 located at the first side end of the magnet plate and the innermost side of the space 19 located at the other side of the first side end of the magnet plate, namely the second side end, but is not limited thereto.

[0149] In this invention, as described Figure 5 As shown, the magnet plates can be disposed above and below the negative pole traveling surface, and the upper and lower magnet plates can be arranged with magnets of opposite polarities facing each other. By disposing of the pair of magnet plates above and below the negative pole traveling surface as described above, the magnetic force in the X-axis direction of the negative pole traveling can be constant, while the magnetic force in the Y-axis direction can vary.

[0150] The apparatus for manufacturing a negative electrode according to the present invention may include having, for example Figure 6 The magnet plate shows the arrangement of unit magnets and magnet modules. Figure 6 As an example of the magnet plate according to the present invention, it can be an upper magnet plate or a lower magnet plate.

[0151] For example Figure 6 The illustrated magnet plate can apply a magnetic field that varies along the X-axis direction, which is the direction of travel of the negative pole. Multiple magnet modules arranged along the X-axis have the same unit magnet arrangement pattern, but are positioned at a predetermined distance relative to adjacent magnet modules. As the negative pole moves along the X-axis, the magnetic force at a specific position can change continuously and periodically.

[0152] Furthermore, a magnetic field with varying intensity along the Y-axis can be applied to the magnet plate. In the magnet plate according to the invention, by arranging vertical and horizontal unit magnets such that the direction of the magnetic field lines changes by 90 degrees each time along the Y-axis, the magnetic force can be repeatedly increased and decreased in the Y-axis direction. The increase and decrease of the magnetic force can have a certain periodicity; for example, the magnetic force can form a sine wave depending on its position in the Y-axis direction. In this case, the periodicity of the magnetic force can vary according to the length (LY) of the unit magnet in the Y-axis direction.

[0153] At this time, the magnet plates are respectively set on the upper and lower sides, and the unit magnets are arranged in such a way that magnets with opposite polarities face each other, so that the direction of the magnetic field lines in the X and Y axis directions will not change.

[0154] Figure 10 The diagram schematically illustrates the intensity of the magnetic force applied according to the width-direction position of the negative electrode when using the apparatus for manufacturing the negative electrode according to the present invention. Figure 10 As shown above, at specific locations along the width direction of the negative electrode, the magnetic force is not constant according to the movement of the negative electrode, but rather varies depending on the magnetic force provided by the magnet module, thereby providing a uniform degree of orientation along the width direction of the negative electrode. Furthermore, by providing different magnetic forces at specific locations along the width direction, a high magnetic force can ultimately be uniformly provided to the negative electrode, further improving its orientation.

[0155] in addition, Figure 11 This schematically illustrates an example of an apparatus for manufacturing a negative pole, wherein a magnet plate with vertical and horizontal unit magnets arranged (the direction of the magnetic field lines changes by 90 degrees each time along the X-axis direction, which is the direction of travel of the negative pole, while the direction of the magnetic force and the direction of the magnetic field lines do not change in the Y-axis direction) is disposed at any point on the upper or lower part of the negative pole travel surface, and a magnet plate with magnets (the magnet plate and the magnets of the aforementioned magnet plate having opposite polarities facing each other) is disposed on another side.

[0156] like Figure 11 As shown, when the magnetic force of the applied magnetic field changes periodically in the direction of travel of the negative electrode, i.e. the X-axis direction, it can cause the active material of the negative electrode to be oriented in a direction perpendicular to the negative electrode current collector, thus maximizing the orientation degree. However, during the high-rate charging process of the battery cell, the negative electrode mixture layer may be peeled off from the negative electrode current collector.

[0157] also, Figure 12 This schematically illustrates an example of an apparatus for manufacturing a negative pole, wherein a magnet plate arranged with vertical and horizontal unit magnets (a uniform magnetic field applied in the X-axis direction, which is the direction of travel of the negative pole, where the magnetic force and magnetic field lines do not change, and the direction of the magnetic force and magnetic field lines changes by 90 degrees each time along the Y-axis direction) is disposed at any point on the upper or lower part of the negative pole travel surface, and a magnet plate with magnets (the magnet plate and the magnets of the aforementioned magnet plate having opposite polarities facing each other) is disposed on another side.

[0158] When the application is like Figure 12 When using the magnet plate shown, a constant magnetic force is provided in the direction of travel of the negative pole, and a high magnetic force is continuously provided depending on the position, thereby ensuring high orientation. However, a low magnetic field is continuously provided in the width direction of the negative pole, which may result in a decrease in the orientation of the negative pole and problems such as obtaining a negative pole with non-uniform orientation in the width direction of the negative pole.

[0159] However, as described above, when a negative electrode is manufactured using a negative electrode manufacturing apparatus having a magnet plate according to a specific embodiment of the present invention, a negative electrode with uniform orientation in the width direction and high overall orientation can be obtained.

[0160] In this invention, the magnet modules may have a predetermined interval. Figures 6 to 9 The image shows a magnet plate according to a specific embodiment of the invention, illustrating an example where there are no gaps between the magnet modules, but this is not a limitation; the magnet modules may have predetermined gaps between them. When there are predetermined gaps between the magnet modules, the gaps are not particularly restricted.

[0161] In this invention, regarding the unit magnets used to compose a magnet module, within a magnet module, the length (LY) in the Y-axis direction, the length (LX) in the X-axis direction, and the thickness of unit magnets of the same type can be the same or different from each other. The LY, LX, and D of vertical unit magnets can be the same as each other, and the LY, LX, and D of horizontal unit magnets can be the same as each other. Furthermore, the LY, LX, and D of unit magnets of different types can be the same as each other or different from each other.

[0162] Furthermore, among different magnet modules, the LY, LX, and D values ​​of the same type of unit magnet can be the same or different from each other. In particular, LX can be different, while LY and D can be the same. That is, the lengths of the magnet modules in the X-axis direction can be different from each other.

[0163] In addition, the thickness of the vertical unit magnet and the thickness of the horizontal unit magnet can be the same or different from each other, without any particular limitation. However, the upper magnet plate and the lower magnet plate can be planes with their XY planes facing the negative pole parallel to each other.

[0164] As described above, by moving a negative electrode current collector coated with a negative electrode mixture within a negative electrode manufacturing apparatus comprising a pair of magnet plates (the pair of magnet plates having an arrangement of unit magnets according to the invention on both sides of the XY plane in which the negative electrode travels), the negative electrode active material within the negative electrode mixture layer can be oriented, thereby shortening the movement path of lithium ions.

[0165] The negative electrode can be manufactured by coating a negative electrode mixture containing a negative electrode active material onto one or both sides of a negative electrode current collector, and then, under the condition of applying a magnetic field, causing the negative electrode current collector coated with the negative electrode mixture to travel between a pair of magnet plates as described above to manufacture the negative electrode.

[0166] Typically, a negative electrode with a negative electrode mixture layer formed on the negative electrode current collector can be manufactured by coating a negative electrode mixture containing a slurry phase of negative electrode active material onto at least one side of the negative electrode current collector, drying it, and then calendering it.

[0167] At this point, as described above, with a magnetic field varying along the Y-axis (the Y-axis direction of the XY plane where the negative electrode travels along the X-axis) applied to the upper and lower sides of the XY plane, the slurry-like negative electrode mixture can be coated onto the negative electrode current collector and dried, thereby oriented the negative electrode active material in a direction perpendicular to the negative electrode current collector. Furthermore, a magnetic field can be applied during the drying process after coating the negative electrode mixture onto the negative electrode current collector, thereby oriented the pores within the negative electrode mixture layer.

[0168] The maximum magnetic force of the magnetic field applied in this invention can be 4000G or more, for example, 4500G or more, 5000G or more, 5500G or more, 6000G or more, 6500G or more, 7000G or more, and can be 8000G or more. Furthermore, the greater the maximum magnetic force, the better the orientation degree of the negative electrode active material within the negative electrode mixture layer can be improved; there is no particular limitation, but the maximum magnetic force can be 12000G or less, for example, 10000G or less.

[0169] Furthermore, the magnetic field can be applied to the negative electrode mixture layer for more than 1 second, for example, more than 1.5 seconds, more than 2 seconds, more than 3 seconds, or more than 4 seconds, and can be applied for less than 30 seconds, for example, less than 25 seconds, less than 20 seconds, less than 15 seconds, or less than 10 seconds.

[0170] As another example, the negative electrode current collector coated with the negative electrode mixture slurry can be made to travel at a speed of, for example, from 0.1 m / min to 50 m / min, but is not limited thereto. The slower the travel speed of the negative electrode current collector, the longer the negative electrode mixture remains in the magnetic field, thus improving the orientation of the negative electrode active material.

[0171] The viscosity of the negative electrode mixture in the slurry phase may affect the orientation of the negative electrode active material caused by the application of a magnetic field. For example, the lower the viscosity of the negative electrode mixture, the less resistance it will resist the flow of the negative electrode mixture, even if the magnetic force and magnetic field are applied for the same time. Therefore, it is easier for the negative electrode active material to be oriented in a direction perpendicular to the negative electrode current collector.

[0172] As a specific implementation plan, at 25℃ and 0.1s -1 The viscosity of the negative electrode mixture slurry measured at the specified shear rate can be below 300,000 cp. The viscosity of the negative electrode mixture slurry can be, for example, below 150,000 cp, below 130,000 cp, below 100,000 cp, below 75,000 cp, below 50,000 cp, below 35,000 cp, below 30,000 cp, below 27,500 cp, or below 25,000 cp.

[0173] In addition, there is no particular limitation on the lower limit of the viscosity of the negative electrode mixture slurry, but it can be above 5000 cp (at 25°C and a shear rate of 0.1 s⁻¹). -1 When the viscosity of the negative electrode mixture slurry is too low, the negative electrode active material in the negative electrode mixture slurry may easily precipitate.

[0174] The drying process described is used to remove the solvent contained in the negative electrode mixture. There are no particular limitations on the drying method; therefore, conventional drying methods can be applied, such as natural drying, heat drying, reduced pressure drying, and forced air drying, and the process can be carried out in steps.

[0175] The drying process is not particularly limited, but it can be carried out for 20-300 seconds in a range of, for example, 60-180°C, preferably in a range of 70-150°C, such as 40-240 seconds or 60-200 seconds.

[0176] Following the drying process, a calendering process can be performed. This calendering process allows for the adjustment of the thickness or density of the negative electrode mixture layer. The calendering process can be carried out using conventional methods such as rolling or flat pressing. Through this process, the thickness of each side of the negative electrode mixture layer can be made to be 20 μm or more and 120 μm or less, for example, 40 μm or more and 100 μm or 60 μm or more and 80 μm or less.

[0177] The negative electrode obtained by the calendering process can be a negative electrode mixture layer with a density of 1.5 g / cm³. 3 The above refers to high-density electrodes. For example, the density of the negative electrode mixture layer can be 1.5 g / cm³. 3 Above and 2.2g / cm 3 Below or 1.5g / cm 3 Above and 2.0 g / cm 3 The following applies. When the electrode density of the negative electrode meets the above range, the power characteristics, lifespan characteristics, and high-temperature storage characteristics of the battery can be improved during manufacturing.

[0178] According to the present invention, a negative electrode with uniform orientation of the negative electrode active material in the negative electrode mixture layer can be obtained. Therefore, when the negative electrode is analyzed by XRD, the I(110) / I(002) value can be 0.25% or more, for example, the I(110) / I(004) value can be 9% or more. Furthermore, in the XRD analysis, the P / O value of the negative electrode can be less than 0.67.

[0179] In this invention, the negative electrode mixture layer can be formed by coating a negative electrode mixture slurry containing a negative electrode active material, a conductive agent, a binder, and a solvent onto a negative electrode current collector. Furthermore, if necessary, the negative electrode mixture layer may further contain additives such as thickeners.

[0180] The negative electrode active material can be a carbon-based negative electrode active material. Any carbon-based negative electrode active material commonly used in the manufacture of negative electrodes for secondary batteries is also suitable for this invention. There are no particular limitations on the carbon-based negative electrode active material, but it can be artificial graphite, natural graphite, or a mixture of artificial and natural graphite, and can be artificial graphite. Artificial graphite can further improve the dispersibility of the slurry and can improve its lifetime characteristics and high-temperature storage characteristics.

[0181] Compared to amorphous carbon-based active materials, crystalline carbon-based active materials, such as artificial graphite or mixtures of artificial and natural graphite, exhibit more developed crystallographic properties. Therefore, when such crystalline carbon-based active materials are used as negative electrode active materials, the orientation characteristics of carbon materials within the negative electrode mixture layer in response to an external magnetic field can be further improved, and the orientation of the pores can be enhanced.

[0182] The artificial or natural graphite may be in the form of amorphous, flake, scaly, spherical, fibrous, or a combination thereof. Furthermore, when the artificial and natural graphite are mixed, the mixing ratio, by weight, may be 20:80 to 99:1, 50:50 to 97:3, or 70:30 to 95:5.

[0183] The negative electrode active material can be used without particular restriction as long as it has a shape that allows for the insertion and extraction of lithium ions. However, in terms of improving the function of the negative electrode active material for lithium secondary batteries, the aspect ratio can generally be 20 or higher. When a magnetic field is applied while using a negative electrode active material with the aspect ratio described above, the (002) face of the negative electrode active material particles can be oriented in a direction perpendicular to the face of the negative electrode current collector.

[0184] Furthermore, the negative electrode active material may further include at least one of silicon (Si)-based negative electrode active material, tin (Sn)-based negative electrode active material, or lithium vanadium oxide negative electrode active material, in addition to the carbon-based negative electrode active material. When the negative electrode active material further includes these substances, the content of these substances relative to the total weight of the negative electrode active material may be in the range of 1-50% by weight.

[0185] The Si-based negative electrode active material can be Si, Si-C composite, or SiO2. x(0 < x < 2), Si-Q alloy. In the Si-Q alloy, Q can be an element selected from alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Group 15 elements, Group 16 elements, transition metals, rare earth elements, and combinations thereof, other than Si. Specifically, it can be selected from Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof.

[0186] Generally, it is known that Si-based negative electrode active materials, as negative electrode active materials, have the characteristic of large volume change. Therefore, generally, a carbon-based negative electrode active material such as graphite can be further included while including a silicon-based negative electrode active material. At this time, carbon nanotubes can be included as a conductive agent in terms of preventing swelling caused by the volume expansion of the silicon-based negative electrode active material

[0187] The Sn-based negative electrode active material can be Sn, SnO2, Sn-R alloy. In the Sn-R alloy, R is an element selected from alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Group 15 elements, Group 16 elements, transition metals, rare earth elements, and combinations thereof, other than Sn and Si. Specifically, it can be selected from Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, In, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof. In addition, at least one of them can be used in combination with SiO2.

[0188] Relative to the total weight of the negative electrode mixture layer, the content of the negative electrode active material in the negative electrode mixture layer can be 94-98% by weight.

[0189] The conductive agent is used to impart conductivity to the electrode. As long as it is a conductive agent commonly used in secondary batteries, it can be used without limitation. For example, carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, and carbon nanotubes can be used; metal-based materials such as metal powders or metal fibers of copper, nickel, aluminum, silver, etc.; conductive polymers such as polyphenylene derivatives; or conductive materials containing mixtures thereof.

[0190] The content of the conductive agent can be 0.1-3% by weight relative to the total weight of the negative electrode mixture layer.

[0191] The negative electrode mixture layer may contain an adhesive. The adhesive serves to bond the negative electrode active material particles together and to adhere the negative electrode active material to the negative electrode current collector. The adhesive may be a water-based adhesive, but is not limited to this.

[0192] The water-based adhesive may include styrene-butadiene rubber (SBR), acrylated styrene-butadiene rubber, nitrile rubber, acrylic rubber, butyl rubber, ethylene-propylene copolymer, polyepoxychloropropane, polyphosphazene, polyacrylonitrile, polystyrene, ethylene-propylene-diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol resin, acrylate resin, or combinations thereof.

[0193] The content of the binder can be 1.5-3% by weight relative to the total weight of the negative electrode mixture layer.

[0194] The negative electrode mixture layer may further contain a thickener to impart viscosity in addition to the binder. The thickener may be a cellulose-based compound, for example, a mixture of one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, or their alkali metal salts. The alkali metal may be Na, K, or Li. 0.1 to 3 parts by weight of the thickener may be used relative to 100 parts by weight of the negative electrode active material.

[0195] The solvent can be an aqueous solvent such as water.

[0196] In this invention, the negative electrode current collector can be at least one selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and combinations thereof. The thickness of the negative electrode current collector is not particularly limited; for example, the thickness of the negative electrode current collector can be 5-30 μm.

[0197] In a specific embodiment of the present invention, the negative electrode active material in the negative electrode mixture layer is oriented in a direction perpendicular to the negative electrode current collector, which allows lithium ions to easily diffuse into the electrode interior, thereby improving the charge and discharge efficiency at high rates and thus improving battery performance, such as improving fast charging performance.

[0198] A secondary battery can be manufactured using a negative electrode with the negative electrode active material oriented vertically as described above. The secondary battery can be manufactured by alternately stacking the negative and positive electrodes as described above with a separator as the boundary to form an electrode assembly, which is then inserted into a battery casing, sealed, and filled with electrolyte.

[0199] The positive electrode will now be described in more detail. There are no particular limitations on the positive electrode, but the positive electrode mixture layer is formed by coating a slurry phase positive electrode mixture onto at least one side of the positive electrode current collector and then drying and calendering it. Any positive electrode commonly used in secondary batteries is suitable for this invention.

[0200] The positive electrode mixture may contain positive electrode active material, binder and solvent, and may contain conductive agent and thickener as needed.

[0201] The positive electrode active material can be a compound that allows lithium to be reversibly inserted and extracted (lithiation intercalation compound). Specifically, the positive electrode active material can be one or more composite oxides of lithium selected from cobalt, manganese, nickel and combinations thereof.

[0202] As a more specific example, the positive electrode active material can be represented by the general formula LiMO2, and can include layered lithium transition metal compounds (oxides), wherein M can contain at least one transition metal element such as Ni, Co, and Mn, and can further contain other metal elements or non-metal elements. Examples of the composite oxide include, for instance, a monolithic lithium transition metal composite oxide containing one of the aforementioned transition metal elements, a binary lithium transition metal composite oxide containing two of the aforementioned transition metal elements, and a ternary lithium transition metal composite oxide containing Ni, Co, and Mn as transition metal elements as constituent elements. Specifically, it can be Li... x Mn 1-y M y A2, Li x Mn 1-y M y O 2-z X z Li x Mn2O 4-z X z Li x Mn 2-y M y M' z A4, Li x Co 1-y M y A2, Li x Co 1-y M y O 2-z X z Li x Ni 1-y M y A2, Li x Ni 1-y M y O 2-z Xz Li x Ni 1-y Co y O 2-z X z Li x Ni 1-y- z Co y M z A α Li x Ni 1-y-z Co y M z O 2-α X α Li x Ni 1-y-z Mn y M z A α Li x Ni 1-y-z Mn y M z O 2-α X (in the above formulas, 0.9≤x≤1.1, 0≤y≤0.5, 0≤z≤0.5, 0≤α≤2, M and M' are the same or different from each other, and are selected from Mg, Al, Co, K, Na, Ca, Si, Ti, Sn, V, Ge, Ga, B, As, Zr, Mn, Cr, Fe, Sr, V and rare earth elements, A is selected from O, F, S and P, and X is selected from F, S and P), for example, could be Li (Ni 1 / 3 Co 1 / 3 Mn 1 / 3 Ternary lithium transition metal composite oxides such as O2.

[0203] Furthermore, the positive electrode active material can be a lithium transition metal compound (oxide) represented by the general formula Li2MO3, wherein M can contain at least one of the transition metal elements containing Mn, Fe, and Co, and can further contain other metal elements or non-metal elements, such as Li2MnO3 and Li2PtO3.

[0204] Furthermore, the positive electrode active material can be a solid solution of the LiMO2 and the Li2MO3, for example, it can be a solid solution represented by 0.5LiNiMnCoO2-0.5Li2MnO3.

[0205] Furthermore, a substance having a coating on the surface of the positive electrode active material can be used, and the compound and the coating compound can also be used in combination. The coating may contain at least one coating element compound selected from oxides, hydroxides, hydroxyoxides, carbonate oxides, and basic carbonates of coating elements. The compounds forming these coatings may be amorphous or crystalline. The coating elements included in the coating may be Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof.

[0206] In the positive electrode, the content of the positive electrode active material can be 90-98% by weight relative to the solid weight of the positive electrode mixture.

[0207] The adhesive serves to bond the positive electrode active material particles together and to adhere the positive electrode active material to the positive electrode current collector. The adhesive content can be 1.5-5% by weight relative to the solid weight of the positive electrode mixture. The adhesive can be, for example, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, cellulose diacetate, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, polyamide fiber, etc.

[0208] The positive electrode mixture slurry may further include a thickener to impart viscosity in addition to the binder. The thickener may be the same as that included in the negative electrode mixture, and the content of the thickener may be from 0.1 parts by weight to 3 parts by weight relative to 100 parts by weight of the positive electrode active material.

[0209] The conductive agent is used to impart conductivity to the positive electrode. Any conductive agent commonly used in the positive electrode of a secondary battery can be appropriately used, and the conductive agent used in the negative electrode mixture can also be used. Based on the solid weight of the positive electrode mixture, the content of the conductive agent can be 0.1-5% by weight.

[0210] The solvent can be an aqueous solvent such as water, or a non-aqueous solvent. Any non-aqueous solvent commonly used in the preparation of positive electrode mixtures for secondary batteries can be used in this invention; for example, N-methyl-2-pyrrolidone (NMP) can be listed, but is not limited thereto.

[0211] The positive electrode current collector can be made of a metal with good electrical conductivity, such as aluminum, nickel, titanium, or stainless steel, and can be in various forms such as sheet, foil, or mesh. There are no particular limitations on the thickness of the positive electrode current collector; for example, the thickness can be 5-30 μm.

[0212] As described above, a positive electrode with a layer of positive electrode mixture formed on the positive electrode current collector can be manufactured by coating the positive electrode mixture onto at least one side of the positive electrode current collector and then drying and calendering it.

[0213] The drying and rolling processes can be carried out using the same methods as those used to manufacture the negative electrode, therefore specific details are omitted.

[0214] The separator between the positive and negative electrodes can be a porous sheet, non-woven fabric, etc., and can be a multilayer film of polyethylene, polypropylene, polyvinylidene fluoride, or two or more layers thereof, a two-layer mixed multilayer film of polyethylene / polypropylene, a three-layer mixed multilayer film of polyethylene / polypropylene / polyethylene, a three-layer mixed multilayer film of polypropylene / polyethylene / polypropylene, etc., and can have a porous heat-resistant layer on one or both sides of the porous sheet, non-woven fabric, etc. There are no particular limitations on the separator, but a separator with a thickness of, for example, about 10-40 μm can be used.

[0215] The electrolyte may contain a non-aqueous organic solvent and a lithium salt. The non-aqueous organic solvent acts as a medium for the movement of ions participating in the electrochemical reactions of the battery. For example, carbonate-based solvents, ester-based solvents, ether-based solvents, ketone-based solvents, alcohol-based solvents, or aprotic solvents can be used, and solvents commonly used in lithium-ion secondary batteries can be used. The organic solvent can be used alone or in combination. Specifically, examples include propylene carbonate (PC), ethylene carbonate (EC), diethylcarbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), methyl propyl carbonate, dipropyl carbonate, fluoroethylene carbonate (FEC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, vinylene carbonate, sulfolane, γ-butyrolactone, propylene sulfite, and tetrahydrofuran.

[0216] The lithium salt, dissolved in an organic solvent, acts as a lithium-ion supply source within the battery, enabling the lithium-ion secondary battery to operate essentially. Furthermore, the lithium salt promotes the movement of lithium ions between the positive and negative electrodes. Any lithium salt commonly used in electrolytes for lithium-ion secondary batteries can be used without restriction. The lithium salt can be derived from Li... + X - This indicates that there are no particular restrictions on the anion of this lithium salt, but F can be cited as an example. - Cl - ,Br - I - NO3- N(CN)2 - BF4 - ClO4 - PF6 - (CF3)2PF4 - (CF3)3PF3 - (CF3)4PF2 - (CF3)5PF - (CF3)6P - CF3SO3 - CF3CF2SO3 - (CF3SO2)2N - (FSO2)2N - CF3CF2(CF3)2CO - (CF3SO2)2CH - (SF5)3C - (CF3SO2)3C - CF3(CF2)7SO3 - CF3CO2 - CH3CO2 - SCN - and (CF3CF2SO2)2N - wait.

[0217] Specifically, the lithium salt can be selected from LiPF6, LiBF4, LiSbF6, LiAsF6, LiN(SO2C2F5)2, Li(CF3SO2)2N, LiN(SO3C2F5)2, LiC4F9SO3, LiClO4, LiAlO2, LiAlCl4, LiN(C x F 2x+1 SO2)(C y F 2y+1 SO2 (where x and y are each independent integers from 1 to 20), LiCl, LiI, and LiB(C2O4)2 (lithium bis(oxalato) borate, LiBOB) are one or more of these.

[0218] There is no particular limitation on the concentration of the lithium salt, but it can be used in the range of 0.1M to 2.0M. To improve battery life, the electrolyte may further contain vinylene carbonate or vinylene carbonate-based compounds, if necessary.

[0219] In the negative electrode according to the present invention, the negative electrode active material in the negative electrode mixture layer is oriented in a direction perpendicular to the negative electrode current collector, so that lithium ions can easily diffuse into the electrode during the charging and discharging process of the secondary battery, thereby reducing the battery resistance, especially improving the charging and discharging efficiency at high rates, thereby improving cycle life characteristics and fast charging performance. As another specific embodiment, it can prevent the peeling between the negative electrode current collector and the negative electrode mixture layer during high-rate charging and discharging processes.

[0220] According to another specific embodiment, a lithium secondary battery is provided, wherein negative and positive electrodes as described above are alternately stacked with a separator as the boundary. The lithium secondary battery of the present invention can be manufactured by fabricating an electrode assembly with a separator disposed between the positive electrode and the negative electrode according to the present invention, housing it in a battery casing, and injecting electrolyte therein. The shape of the lithium secondary battery of the present invention is not particularly limited, but it can be a pouch battery, a cylindrical or prismatic battery using a can, or a coin-shaped battery.

[0221] Example

[0222] The present invention will be described in more detail below by way of examples. These examples are specific instances of the present invention and are not intended to limit the scope of the invention.

[0223] Comparative Example 1

[0224] Artificial graphite, styrene-butadiene rubber (SBR), and carboxymethyl cellulose (CMC) were mixed in a mass ratio of 97.8:1.2:1.0 and then dispersed in deionized distilled water to form a slurry phase of the negative electrode mixture.

[0225] Using a slit die, the negative electrode mixture of the slurry phase was coated onto copper foil with a width of 150 mm, resulting in a loading weight of 12.5 mg / cm³. 2 .

[0226] A copper foil coated with the negative electrode mixture is passed through a drying device to dry the negative electrode mixture, thereby manufacturing a negative electrode.

[0227] Comparative Example 2

[0228] A vertical unit magnet, with a horizontal and vertical length of 50 mm and a thickness (D) of 20 mm, is used as a neodymium (Nd) magnet. Figure 1 Arranged in the same manner as shown, a lower magnet plate with dimensions of 250mm × 250mm is made.

[0229] Furthermore, the upper magnet plate is manufactured using the same method as the lower magnet plate.

[0230] At this point, the lower and upper magnet plates are configured such that the polarities of their facing surfaces are opposite, and a 40mm gap is placed between them to create a magnet module. This magnet module is positioned immediately in front of the drying apparatus, designed to allow the drying process to begin immediately after the orientation of the negative electrode active material.

[0231] Artificial graphite, styrene-butadiene rubber (SBR), and carboxymethyl cellulose (CMC) were mixed in a mass ratio of 97.8:1.2:1.0 and then dispersed in deionized distilled water to form a slurry phase of the negative electrode mixture.

[0232] Using a slit die, the negative electrode mixture of the slurry phase was coated onto copper foil with a width of 150 mm, resulting in a loading value (load weight) of 12.5 mg / cm³. 2 .

[0233] A copper foil coated with the negative electrode mixture is passed through the magnet module under the application of a magnetic field for magnetic orientation, and then the negative electrode mixture is dried to produce a negative electrode.

[0234] Comparative Example 3

[0235] Vertical and horizontal unit magnets with horizontal and vertical lengths of 50 mm and thickness of 20 mm were used as neodymium magnets, respectively.

[0236] like Figure 11 As shown, the vertical unit magnets and horizontal unit magnets are arranged such that the direction of the magnetic field lines is rotated 90 degrees each time along the X-axis direction that travels along the negative pole.

[0237] This allows for the creation of a magnet plate with an overall size of 250mm × 250mm.

[0238] The magnet plate is placed at the lower part of the negative pole traveling surface to create a magnet module.

[0239] The magnet module is positioned immediately in front of the drying device, designed to allow the drying process to begin immediately after the orientation of the negative electrode active material.

[0240] The negative electrode is manufactured by passing it through the magnet module for 2 seconds in the same manner as in Comparative Example 2 for magnetic orientation, and then drying the negative electrode mixture.

[0241] Comparative Example 4

[0242] Vertical and horizontal unit magnets with horizontal and vertical lengths of 50 mm and thickness of 20 mm were used as neodymium magnets, respectively.

[0243] like Figure 12As shown, the vertical unit magnets and horizontal unit magnets are arranged such that the direction of the magnetic field lines is rotated 90 degrees each time along the Y-axis direction, which is perpendicular to the X-axis direction of the negative pole.

[0244] This allows for the creation of a lower magnet plate with an overall size of 250mm × 250mm.

[0245] Furthermore, the upper magnet plate is manufactured using the same method as the lower magnet plate. In this case, the lower and upper magnet plates are configured such that the polarities of their facing surfaces are opposite.

[0246] The lower magnet plate and the upper magnet plate are separated by a 40mm gap to create a magnet module.

[0247] The magnet module is positioned immediately in front of the drying device, designed to allow the drying process to begin immediately after the orientation of the negative electrode active material.

[0248] The negative electrode is manufactured by passing it through the magnet module for 2 seconds in the same manner as in Comparative Example 2 for magnetic orientation, and then drying the negative electrode mixture.

[0249] Example 1

[0250] Vertical and horizontal unit magnets, each with a horizontal and vertical length of 50 mm and a thickness of 20 mm, were used as neodymium magnets. Figure 6 As shown, two magnet modules are manufactured by arranging the magnetic field lines in a manner that rotates 90 degrees each time along the Y-axis relative to the XY plane that travels along the X-axis relative to the negative pole.

[0251] The magnet modules are sequentially arranged along the X-axis to manufacture the lower magnet plate. Starting with the second magnet module, it is positioned at a point d = 50 mm away from the adjacent preceding magnet module along the Y-axis. This process produces... Figure 6 The lower magnet plate is shown in the form shown.

[0252] Furthermore, the upper magnet plate is manufactured using the same method as the lower magnet plate, wherein unit magnets are arranged such that the polarities of the faces of the lower and upper magnet plates facing each other are opposite to each other, thereby manufacturing the upper magnet plate.

[0253] A magnetic field application device is made by separating the lower magnet plate and the upper magnet plate by a 40mm interval.

[0254] The magnetic field application device is positioned immediately in front of the drying device, designed to perform the drying process immediately after the orientation of the negative electrode active material.

[0255] Artificial graphite, styrene-butadiene rubber (SBR), and carboxymethyl cellulose (CMC) were mixed in a mass ratio of 97.8:1.2:1.0 and then dispersed in deionized distilled water to form a slurry phase of the negative electrode mixture.

[0256] Using a slit die, the negative electrode mixture of the slurry phase was coated onto copper foil with a width of 150 mm, resulting in a loading value (load weight) of 12.5 mg / cm³. 2 .

[0257] The copper foil is passed through the magnetic field applying device for 4 seconds under the applied magnetic field to perform magnetic orientation, and the negative electrode mixture is dried to produce the negative electrode.

[0258] Example 2

[0259] The negative electrode is manufactured using the same method as in Example 1, except that d is adjusted to 20 mm, and a magnetic field application device is manufactured equipped with an upper magnet plate and a lower magnet plate (the upper and lower magnet plates have 5 magnet modules), and the negative electrode is manufactured using the magnetic field application device.

[0260] Evaluation of physical properties

[0261] [P / O]

[0262] For each negative electrode manufactured in Comparative Examples 1 to 4 and Examples 1 to 2, the preferred orientation (P / O) of the negative electrode active material was measured at 10 points at 10 mm intervals along the width direction (Y-axis direction) of the negative electrode using XRD.

[0263] The smaller the P / O value, the better the vertical orientation of the negative electrode active material.

[0264] The P / O values ​​measured above are shown in... Figure 13 middle.

[0265] from Figure 13 It is evident that the negative poles of Embodiments 1 and 2, which utilize the magnet plates according to the present invention, exhibit the best vertical orientation, and it can be confirmed that they have a uniform orientation distribution in the width direction.

Claims

1. An apparatus for manufacturing a negative electrode, comprising a pair of magnet plates, an upper magnet plate and a lower magnet plate disposed above and below the negative electrode in an XY plane traveling along the X-axis direction. in, The magnet plate comprises (N+1) magnet modules, where N is greater than or equal to 1. The first vertical unit magnet with its magnetic field lines pointing upwards, the second vertical unit magnet with its magnetic field lines pointing downwards, the first horizontal unit magnet with its magnetic field lines pointing to the left, and the second horizontal unit magnet with its magnetic field lines pointing to the right are arranged in a specific pattern along one direction of the Y-axis. The magnet modules are arranged along the X-axis in a manner parallel to the XY plane. When the Y-coordinate of the first unit magnet of the first magnet module is set to 0, the absolute value of the Y-coordinate of the first unit magnet of the (N+1)th magnet module is N×d. The first unit magnet of the (N+1)th magnet module is of the same type as the first unit magnet of the Nth magnet module, and the first unit magnet of the (N+1)th magnet module is located at the origin (O) of the Nth magnet module. N The position is located at a point where a straight line parallel to the X-axis moves a distance d along one direction of the Y-axis, where the distance d is less than the width of the unit magnet.

2. The apparatus for manufacturing a negative electrode according to claim 1, wherein, The distance d is n times the value obtained according to any one of equations (1) to (5). Where n is a natural number greater than or equal to 1, LY1 is the length of the first vertical unit magnet in the Y-axis direction, LY3 is the length of the second vertical unit magnet in the Y-axis direction, LY2 is the length of the first horizontal unit magnet in the Y-axis direction, LY4 is the length of the second horizontal unit magnet in the Y-axis direction, and N+1 is the number of magnet modules that make up the magnet plate.

3. The apparatus for manufacturing a negative electrode according to claim 1, wherein, The magnet module has a unit magnet arrangement mode in which the direction of the magnetic field lines changes by 90 degrees each time along the Y-axis.

4. The apparatus for manufacturing a negative electrode according to claim 1, wherein, The (N+1)th magnet module has the same unit magnet arrangement pattern as the Nth magnet module.

5. The apparatus for manufacturing a negative electrode according to claim 1, wherein, The last magnet module included in the magnet plate is located at a position that is moved 2n unit magnets relative to the first magnet module in the Y-axis direction, where n is a natural number greater than or equal to 1.

6. The apparatus for manufacturing a negative electrode according to claim 1, wherein, The magnet module has horizontal unit magnets at both ends.

7. The apparatus for manufacturing a negative electrode according to claim 1, wherein, The upper magnet plate and the lower magnet plate have magnets with opposite polarities facing each other.

8. The apparatus for manufacturing a negative electrode according to claim 1, wherein, The magnetic force of the magnet plate changes in the Y-axis direction.

9. The apparatus for manufacturing a negative electrode according to claim 1, wherein, The unit magnets included in a magnet module of the magnet plate have the same length (LX) in the X-axis direction.

10. The apparatus for manufacturing a negative electrode according to any one of claims 1 to 9, wherein, The magnet plate includes three or more long magnet modules and at least one short magnet module. The length of the long magnet module is the same as the length of the magnet plate in the Y-axis direction, and the length of the short magnet module is shorter than the length of the magnet plate in the Y-axis direction. The two ends of the long magnet module are respectively aligned with a straight line parallel to the X-axis of the magnet plate.

11. The apparatus for manufacturing a negative electrode according to claim 10, wherein, The length difference between the short magnet module and the length of the magnet plate in the Y-axis direction is less than or equal to the length of the unit magnet.

12. The apparatus for manufacturing a negative electrode according to claim 10, wherein, The two ends of the short magnet module are separated from the long magnet module by straight lines.

13. The apparatus for manufacturing a negative electrode according to claim 10, wherein, Vertical unit magnets are provided at both ends of the short magnet module.

14. The apparatus for manufacturing a negative electrode according to claim 10, wherein, At least one of the long magnet modules has partial vertical unit magnets at both ends, the length of which is less than the length of the first vertical unit magnet or the second vertical unit magnet.

15. The apparatus for manufacturing a negative electrode according to claim 14, wherein, The lengths of the vertical unit magnets located at the two side ends may be the same or different from each other.

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