Magnetic alignment apparatus and magnetic alignment method of electrode active material in electrode using same

Abstract

The present invention relates to a magnetic alignment apparatus and a magnetic alignment method of an electrode active material in an electrode using same. The magnetic alignment apparatus has a structure in which the directionality of the N-pole and the S-pole of each of a plurality of unit magnets included in a first magnet unit and a second magnet unit is controlled to magnetize a magnetizable member positioned between the unit magnets, and a magnetic field is applied to an electrode slurry by means of the magnetized magnetizable member. Accordingly, the magnetic alignment apparatus can perform magnetic alignment of an electrode active material in an electrode with high efficiency during the manufacture of an electrode for a lithium secondary battery. In addition, the magnetic alignment apparatus can easily control whether to apply a magnetic field according to whether the magnetizable member is magnetized, thereby having excellent workability and high economic feasibility during electrode manufacturing.

Description

Magnetic alignment device and method for magnetic alignment of electrode active material in electrode using the same

[0001] The present invention relates to a magnetic alignment device capable of controlling whether a magnetic field is applied and a method for magnetically aligning an electrode active material in an electrode using the same.

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2023-0196666, dated December 29, 2023, the entire contents of which are incorporated herein by reference.

[0003]

[0004] Recently, secondary batteries are widely used not only in small devices such as portable electronic devices, but also in medium and large devices such as battery packs for hybrid or electric vehicles or power storage devices.

[0005] These secondary batteries are rechargeable power generation devices composed of a stacked structure of anode / separator / cathode. Generally, the cathode contains lithium metal oxide as a cathode active material, and the anode contains a carbon-based cathode active material such as graphite. When charging, lithium ions released from the cathode are absorbed into the carbon-based cathode active material of the anode, and when discharging, lithium ions contained within the carbon-based cathode active material are absorbed into the lithium metal oxide of the cathode, so that charging and discharging are repeated.

[0006] Among these, graphite materials such as natural graphite can be used as negative electrode active materials. This graphite has a layered structure, and carbon atoms form a network structure and are formed by stacking multiple layers in a planar shape. During charging, lithium ions invade the edge surfaces (surfaces where the layers overlap) of these graphite layers and diffuse between the layers. Furthermore, during discharge, lithium ions can be desorbed and released from the edge surfaces of the layers. Accordingly, since graphite has a lower electrical resistivity in the plane direction of the layers than in the stacking direction of the layers, a circuitous conduction path for electrons is formed along the plane direction of the layers.

[0007] In conventional lithium secondary batteries using graphite, a technique for magnetically aligning the graphite contained in the negative electrode has been proposed to improve the charging performance of the negative electrode. Specifically, during the formation of the negative electrode, the (002) crystal plane of the graphite is aligned and fixed so that it is nearly perpendicular to the electrode current collector in a magnetic field. In this case, since the edge surface of the graphite layer faces the positive electrode active layer, the insertion and deintercalation of lithium ions are smoothly performed, and at the same time, the conduction path of electrons is shortened, so that the electronic conductivity of the negative electrode can be improved, thereby improving the charging performance of the battery.

[0008] This alignment of graphite can be induced by applying a magnetic field to the undried electrode slurry, and the magnetic field can be performed by placing a magnet on the surface of the electrode current collector to which the electrode slurry is applied. However, the magnet may be an electromagnet or a permanent magnet, but in the case of an electromagnet, a considerable amount of energy is required to orient the graphite, so there is a problem of low economic efficiency. Therefore, from an economic perspective, a magnetic alignment device including a permanent magnet is often installed in the anode manufacturing facility. However, a general anode manufacturing facility is designed to be able to manufacture a variety of models of anodes with different specifications, and when an alignment device including a permanent magnet is introduced into the anode manufacturing facility, there is a problem that the specifications of the anodes that can be manufactured by the anode manufacturing facility are significantly limited due to the magnetic force of the permanent magnet included in the magnetic alignment device.

[0009] Accordingly, attempts have been made to shield the magnetic force generated by the permanent magnets of the magnetic alignment device, when necessary, using magnetic shielding films and the like. However, these methods suffer from the inconvenience of having to attach and / or detach the magnetic shielding film to the magnetic alignment device during the process, which reduces productivity. Furthermore, to completely shield the magnetic force of the permanent magnets contained in the magnetic alignment magnet, the magnetic shielding film must be significantly thicker, complicating the equipment structure and hindering maintenance.

[0010] Therefore, there is a need for the development of a technology that can provide a magnetic alignment device for magnetic field alignment of electrode active materials within an electrode, and turn the magnetic field of the magnetic alignment device on / off according to the specifications of the electrode being manufactured.

[0011]

[0012] [Prior Art Literature]

[0013] Republic of Korea Patent Publication No. 10-2019-0049803

[0014]

[0015] The purpose of the present invention is to provide a magnetic alignment device including a magnet for magnetic alignment of an electrode active material in an electrode for a lithium secondary battery, and capable of easily controlling whether a magnetic field is applied as needed, and a magnetic alignment method using the same.

[0016]

[0017] To solve the above-mentioned problem,

[0018] The present invention,

[0019] It includes a first magnet part and a second magnet part positioned respectively at the upper and lower portions along the transport direction of the electrode current collector to which the electrode slurry is applied to apply a magnetic force.

[0020] The first magnet portion and the second magnet portion each have a structure in which n unit magnets and n-1 magnetizable members are alternately arranged in the width direction of the electrode current collector (where n is an integer from 2 to 20),

[0021] Each unit magnet has a N pole and a S pole, and is arranged so that the poles of the same polarity as those of adjacent unit magnets face each other when a magnetic field is applied.

[0022] The above magnetization member provides a magnetic alignment device that is magnetized with a different polarity than the adjacent unit magnets.

[0023] At this time, the magnetizable member of the first magnet portion can be magnetized with a different polarity from the magnetizable member of the second magnet portion when a magnetic field is applied.

[0024] In addition, each of the n unit magnets includes a rotation axis at the boundary between the N pole and the S pole, and when no magnetic field is applied, each rotation axis can rotate in the same direction so that the N pole or the S pole of the unit magnet faces the electrode current collector.

[0025] The first magnet section and the second magnet section may include a base frame that provides a space for positioning n unit magnets and n-1 magnetizable elements included in each magnet section at the upper and lower portions of the electrode current collector being transported, a fixing guide that is supported by the base frame and fixes the n-1 magnetizable elements, and a rotation unit that is supported by the base frame and rotates a rotation shaft included in the n unit magnets.

[0026] Meanwhile, the magnetization member may have a ratio of the total length in the width direction of the electrode current collector to the width of the electrode slurry in the range of 101% to 200%.

[0027] Additionally, the first magnet portion and the second magnet portion may have a separation distance ranging from 10 mm to 1,000 mm.

[0028] Additionally, the magnetic field strength of the unit magnet may range from 2,000 G to 8,000 G.

[0029] Additionally, the magnetizable member may be composed of a ferromagnetic material containing at least one of iron, nickel, cobalt, and chromium.

[0030] In addition, the unit magnet may be a permanent magnet.

[0031]

[0032] Furthermore, the present invention,

[0033] It includes a step of applying a magnetic field to the electrode slurry applied to the electrode current collector using a first magnet part and a second magnet part respectively located at the upper and lower portions based on the surface of the electrode current collector,

[0034] The first magnet portion and the second magnet portion each have a structure in which n unit magnets and n-1 magnetizable members are alternately arranged in the width direction of the electrode current collector (where n is an integer from 2 to 20),

[0035] Each unit magnet has a north pole and a south pole, and a method for magnetic alignment of an electrode active material within an electrode is provided in which the poles of the same polarity as those of adjacent unit magnets are controlled to face each other when a magnetic field is applied.

[0036] Here, the magnetizable member of the first magnet portion can be magnetized with a different polarity from the magnetizable member of the second magnet portion when a magnetic field is applied.

[0037] In addition, each of the n unit magnets includes a rotation axis at the boundary between the N pole and the S pole, and when no magnetic field is applied, the N pole or the S pole of the unit magnet can rotate in the same direction so as to face the electrode current collector.

[0038] In addition, the first magnet portion and the second magnet portion may be spaced apart so that the magnetic field strength of the magnetizable member represented by Equation 1 below is greater than the magnetic force of the unit magnet when a magnetic field is applied:

[0039] [Formula 1]

[0040] y=-a·ln(x)+b

[0041] (In the above equation 1,

[0042] x represents the separation distance between the first magnet part and the second magnet part (unit: mm),

[0043] y represents the magnetic field strength (unit: G) of the magnetizable member when a magnetic field is applied.

[0044] a and b are 5600≤a≤6000 and 26000≤b≤30000).

[0045]

[0046] The magnetic alignment device according to the present invention can perform magnetic alignment of electrode active materials within an electrode with high efficiency during electrode manufacturing. Furthermore, the magnetic alignment device can easily control whether a magnetic field is applied depending on whether a magnetizable member is magnetized, thereby providing the advantages of excellent workability and high economic efficiency during electrode manufacturing.

[0047] Furthermore, the magnetic alignment method using the magnetic alignment device can selectively apply a magnetic field at predetermined intervals along the transport direction of the electrode current collector during electrode manufacturing, and thus has the advantage of being able to manufacture electrodes with more diverse performance and specifications.

[0048]

[0049] Figure 1 is a schematic structural diagram showing an electrode manufacturing device.

[0050] Fig. 2 is a cross-sectional view schematically showing the structure of a magnetic alignment device applied to a conventional electrode manufacturing device.

[0051] FIG. 3 is a cross-sectional view of a magnetic alignment device according to the present invention cut in the width direction (y direction) of an electrode current collector (or electrode sheet) when a magnetic field is applied.

[0052] Figure 4 is a perspective view schematically showing the structure of a magnetic alignment device according to the present invention.

[0053] FIG. 5 is a cross-sectional view showing the arrangement of unit magnets and magnetizable members provided in the first magnet section and the second magnet section in the width direction (y direction) of the electrode current collector when a magnetic field is applied to the magnetic alignment device according to the present invention.

[0054] FIG. 6 is a cross-sectional view showing the arrangement of unit magnets and magnetizable members provided in the first magnet section and the second magnet section in the width direction (y direction) of the electrode current collector when a magnetic field is not applied to the magnetic alignment device according to the present invention.

[0055]

[0056] The present invention can be modified in various ways and has many embodiments, and specific embodiments will be described in detail in the detailed description.

[0057] However, this is not intended to limit the present invention to a specific embodiment, but should be understood to include all modifications, equivalents, or substitutes included in the technical scope of the present invention.

[0058] In the present invention, it should be understood that terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0059]

[0060] Hereinafter, the present invention will be described in more detail.

[0061]

[0062] magnetic alignment device

[0063] The present invention,

[0064] It includes a first magnet part and a second magnet part positioned respectively at the upper and lower portions along the transport direction of the electrode current collector to which the electrode slurry is applied to apply a magnetic force.

[0065] The first magnet portion and the second magnet portion each have a structure in which n unit magnets and n-1 magnetizable members are alternately arranged in the width direction of the electrode current collector (where n is an integer from 2 to 20),

[0066] Each unit magnet has a N pole and a S pole, and is arranged so that the poles of the same polarity as those of adjacent unit magnets face each other when a magnetic field is applied.

[0067] The above magnetization member provides a magnetic alignment device that is magnetized with a polarity different from that of adjacent unit magnets.

[0068]

[0069] The magnetic alignment device according to the present invention refers to a device applied when manufacturing an electrode used in a lithium secondary battery.

[0070] The above magnetic alignment device can align the crystal plane of the electrode active material contained in the electrode slurry at a large angle close to perpendicular to the electrode current collector by applying a magnetic field to the electrode slurry applied to the surface of the electrode sheet, specifically, the surface of the electrode current collector. To this end, the magnetic alignment device is provided with a magnet for applying a magnetic field to the carbon-based negative electrode active material contained in the electrode slurry.

[0071] Specifically, FIG. 1 is a structural diagram schematically showing the structure of an electrode manufacturing device (1) including a magnetic alignment device (10) according to the present invention. Referring to FIG. 1, the magnetic alignment device (10) has a configuration including a magnet section (110) that applies a magnetic field to the upper and lower portions of an electrode current collector (C) along the transport direction (x-axis direction) of the electrode current collector; and a drying section (120) that dries electrode slurry of the electrode current collector to which a magnetic field is applied by the magnet section.

[0072] The above magnet portions (110) are respectively arranged on the upper and lower sides of the electrode sheet being transported, and serve to apply a magnetic field to each side of the electrode sheet. At this time, the magnet portions (110) include a first magnet portion (110a) and a second magnet portion (110b) arranged on the upper and lower sides of the electrode sheet, respectively, so that when a magnetic field is applied to the electrode slurry (S) applied on the electrode current collector (C), the magnetic field is uniformly applied to the side (i.e., the upper side) where the electrode slurry (S) is exposed and the side (i.e., the lower side) where the current collector (C) is exposed.

[0073] At this time, the first magnet part (110a) and the second magnet part (110b) have different polarities of magnetism, so that the direction of the magnetic force line between them is perpendicular to the surface of each magnet part, thereby applying a magnetic field to the electrode slurry (ES) being transported, thereby performing the function of inducing magnetic alignment of the electrode active material included in the electrode slurry.

[0074] The first magnet section (110a) and the second magnet section (110b) above include a plurality of unit magnets and a plurality of magnetizable members magnetized thereby. The polarity arrangement of the unit magnets included in each magnet section is adjusted so that the poles of the same polarity as those of adjacent unit magnets face each other, thereby simultaneously generating a magnetic force concentration due to reinforcement of magnetic force lines and a reverse magnetic field due to cancellation. Accordingly, the unit magnets can perform the function of transmitting the reinforced magnetic field to the magnetizable members instead of directly applying a magnetic field to each surface of the electrode sheet. The magnetizable members provided between them can collect the reinforced magnetic field and perform the function of applying the magnetic field to the surface of the electrode sheet. The magnetic alignment device according to the present invention has a technical feature of controlling whether to apply a magnetic field without moving each magnet section or having separate additional equipment by having a method of applying a magnetic field to the electrode sheet through the magnetizable members.

[0075] Specifically, the magnet part of the conventional magnetic alignment device has a structure in which a pair of permanent magnets having a single polarity are arranged above and below the electrode sheet being transported, i.e., the electrode current collector (C) and the electrode slurry (ES) applied on the current collector, as shown in Fig. 2, but are arranged so as to have different polarities. The electrode sheet passing between the permanent magnets is directly affected by the magnetic field lines generated between the British magnets. Since the magnetic alignment device with this structure has a structure in which the permanent magnets are fixed and difficult to move or change in position, it is difficult to selectively control whether or not a magnetic field is applied to the electrode sheet.

[0076] However, since the present invention has a method in which a magnetizable member magnetized by a unit magnet rather than a unit magnet of each magnetic part as described above applies a magnetic field to the electrode sheet, it is possible to selectively control whether a magnetic field is applied to the electrode sheet through magnetization and non-magnetization of the magnetizable member.

[0077] To this end, the first magnet portion (110a) and the second magnet portion (110b) according to the present invention may have a structure in which a plurality of unit magnets and a plurality of magnetizable members are alternately arranged in the width direction (or y-axis direction) of the electrode current collector (C). At this time, the plurality of unit magnets may be arranged such that the poles of the same polarity as those of adjacent unit magnets face each other.

[0078] Specifically, the first magnet portion (110a) and the second magnet portion (110b) may have a structure in which n unit magnets (upper: 111a-1 to 111a-n / lower: 111b-1 to 111b-n) and n-1 magnetizable members (upper: 112a-1 to 112a-(n-1) / lower: 112b-1 to 112b-(n-1)) are alternately arranged, as shown in FIGS. 3 and 4. Here, n is an integer of 2 or more, and specifically, may be an integer of 2 to 20, 2 to 15, 2 to 10, 2 to 8, or 2 to 5.

[0079] In addition, the unit magnets may include both N and S poles in one magnet. The first magnet section (110a) and the second magnet section (110b) can control whether or not a magnetizable member in contact with the unit magnet is magnetized and the polarity when magnetized by controlling the direction of the magnetic force lines of each unit magnet and the type of polarity of the pole located at the end.

[0080] The above "magnetization" refers to the generation or reaction of a magnetic moment within a material due to an external magnetic field, thereby acquiring magnetism. In the present invention, when a magnetizable member is placed so as to be in contact between a pair of unit magnets, it may mean that the magnetizable member exhibits a magnetic force of a polarity opposite to the polarity of the unit magnets at the boundary between them. For example, a magnetizable member in contact with the north pole of a pair of unit magnets may exhibit a magnetic force of a south pole, which is the opposite polarity.

[0081] That is, the first magnet part (110a) and the second magnet part (110b) according to the present invention alternately arrange n unit magnets including both N poles and S poles in one magnet with n-1 magnetizable elements, and when a magnetic field of the magnetic alignment device (1) is applied, the N pole and / or S pole of any unit magnet is arranged so that the poles of the same polarity as those of adjacent unit magnets face each other, so that the magnetizable elements interposed between them can be induced to be magnetized with the opposite polarity of the corresponding polarity.

[0082] As an example, the first magnet portion (110a) and the second magnet portion (110b) may be arranged such that one magnet portion has four unit magnets and three magnetizable members alternately arranged (n=4), as shown in FIGS. 3 and 5. At this time, the first magnet portion (110a) may be arranged such that the N pole of the first unit magnet (111a-1) and the N pole of the second unit magnet (111 a-2) face each other, and the S pole of the second unit magnet (111 a-2) may be arranged such that the S pole of the third unit magnet (111 a-3) faces each other. In this way, n unit electrodes can be arranged so that their polarities are the same as those of adjacent unit magnets along the width direction (y-axis direction) of the electrode current collector, and n-1 magnetizable members (112a-1 to 112a-(n-1)) interposed therebetween can be magnetized with a polarity different from that of the adjacent unit magnets. For example, the first magnetizable members (112a-1) arranged between the N pole of the first unit magnet (111a-1) and the N pole of the second unit magnet (111 a-2) can be magnetized with a S pole.

[0083] In addition, each unit magnet (111b-1 to 111b-n) included in the second magnet section may be arranged to have a different polarity from the unit magnet of the first magnet section facing in the z-axis direction. For example, the first unit magnet (111b-1) and the second unit magnet (111b-2) of the second magnet section (110b) may be arranged so that their S poles face each other along the width direction (y-axis direction) of the electrode current collector.

[0084] Accordingly, the magnetizable members interposed between the unit magnets of the second magnet section can be magnetized to have a different polarity from the magnetizable members of the first magnet section facing in the z-axis direction, and thus a strong magnetic field can be generated in the vertical direction based on the surface of each magnet section between the magnetizable members of the first magnet section (110a) and the magnetizable members of the second magnet section (110b).

[0085] In addition, the unit magnets of each magnet section can rotate to prevent a magnetic field from being generated between the first magnet section (110a) and the second magnet section (110b) when the magnetic field of the magnetic alignment device (1) is not applied, and accordingly, magnetization of the magnetizable member may not be induced.

[0086] Specifically, each of the n unit magnets may include a rotation axis at the boundary between the N pole and the S pole. The rotation axis may rotate the unit magnet including the rotation axis in order to change the direction of the magnetic force lines implemented at the poles of the unit magnets. At this time, the rotation may be adjusted so that the unit magnets included in the first magnet section (110a) and the second magnet section (110b) can rotate in the same direction and at the same angle at the same time.

[0087] As an example, each of the unit magnets (upper: 111a-1 to 111a-n / lower: 111b-1 to 111b-n) included in the first magnet section (110a) and the second magnet section (110b) may include a rotation axis (upper: 113a-1 to 113a-n / lower: 113b-1 to 113b-n) as shown in FIGS. 3 and 6. When the magnetic field of the magnetic alignment device (1) is not applied, the rotation axes may all simultaneously rotate 90° in the clockwise direction so that the poles of the unit magnets including the rotation axes may be arranged to face the surface of the electrode current collector (or electrode sheet). By the rotation of the unit magnets, the direction of the magnetic field lines of the unit magnets deviates from the magnetizable member, so that the magnetizable member can be demagnetized. In addition, the unit magnets of the rotated first magnet part (110a) and the unit magnets of the second magnet part (110b) do not induce magnetic lines of force in the vertical direction based on the surface of each magnet part because the poles of the same polarity are opposite each other. At this time, the influence of the magnetic lines of force generated between them is significantly weakened due to the distance between the first magnet part and the second magnet part. Therefore, the electrode current collector (or electrode sheet) being transported at this time does not have a magnetic field applied to its surface.

[0088] Meanwhile, the first magnet portion (110a) and the second magnet portion (110b) may have a structure for fixing the magnetizable member included in the magnet portion at a predetermined position while facilitating the rotation of the unit magnets included in the magnet portion.

[0089] As an example, the first magnet portion and the second magnet portion may include a base frame (115) that provides a space for positioning n unit magnets and n-1 magnetizable elements included in each magnet portion (110a and 110b) at the upper and lower portions of the electrode current collector (C) being transported, as shown in FIG. 4; a fixing guide (upper: 114a-1 to 114a-(n-1) / lower: 114b-1 to 114b-(n-1)) supported by the base frame and fixing each of the opposite ends of the n-1 magnetizable elements; and a rotation unit (not shown) that rotates a rotation shaft (upper: 113a-1 to 113a-n / lower: 113b-1 to 113b-n) supported by the base frame and included at both ends of the n unit magnets.

[0090] Here, the base frame (115) may have a skeletal structure that surrounds the outer side of the first magnet portion (110a) and the second magnet portion (110b), thereby providing a space for positioning the unit magnets and magnetizable members included in each magnet portion (110a and 110b).

[0091] The above base frame (115) may be composed of a material that is difficult to magnetize due to the magnetism of the unit magnets so as not to have a magnetic effect on the unit magnets and magnetizable members included in each magnetic section. For example, the above base frame (115) may be composed of a synthetic resin material or a non-magnetic ceramic material.

[0092] In addition, a rotation unit connected to the rotation axis of the unit magnet included in each magnet section and a fixed guide connected to both ends of each magnetizable member along the transport direction (or x-axis direction) of the electrode current collector (C) can be supported on the inside of the base frame (115).

[0093] The above-mentioned fixing guide may be applied without particular limitations as long as it is made of a material and has a shape that can fix the magnetized member of each magnet part. For example, the above-mentioned fixing guide may be composed of a synthetic resin material or a non-magnetic ceramic material, similar to the base frame (115).

[0094] In addition, the above-described rotation unit may include a plurality of connecting means in one rotation unit to be connected to the rotation axes individually included in the plurality of unit magnets, and in some cases, a plurality of rotation units individually connected to each rotation axle may be provided inside the base frame (115).

[0095] The above rotation unit is not particularly limited in form or type as long as it can rotate the rotation axis of the unit magnet. For example, the rotation unit may include an electric motor driven by an electric power source or a handwheel that can be manually operated by an operator.

[0096] In addition, the above-mentioned rotation unit may be electrically connected to a control unit that controls the rotation axis of the unit magnet to rotate depending on whether a magnetic field of the magnetic alignment device is applied, if the rotation unit includes a motor. At this time, the control unit may control the motor so that each unit magnet connected to the motor can rotate in the same direction and at the same angle at the same time.

[0097]

[0098] Meanwhile, the above unit magnet is one that is commonly applied in the art, and can be applied without any particular limitation as long as the magnetic forces of the N pole and the S pole are equally divided and a plurality of unit magnets are arranged together with a plurality of magnetizable members to form one surface.

[0099] As an example, the unit magnet may have a rectangular rod shape with equally divided magnetic forces of the N pole and the S pole, as shown in Fig. 4. The magnet portion including the unit magnet may have one magnet arranged in the longitudinal direction along the transport direction (or x-axis direction) of the electrode current collector being transported.

[0100] As another example, the unit magnet may have a cube shape with the magnetic forces of the N pole and the S pole equally divided. In this case, the magnet section including the unit magnet may be arranged so that a plurality of unit magnets form a row along the transport direction (or x-axis direction) of the transported electrode current collector.

[0101] In addition, the unit magnet may include a permanent magnet. The permanent magnet may include both ferromagnetic magnets and soft magnetic magnets, including NdFeB magnets, SmCo magnets, Ferrite magnets, Alnico magnets, FeCrCo magnets, Bond magnets (Nd-Fe-B, Sm-Fe-N, Sm-Co, Ferrite), etc.

[0102] In addition, the magnetizable member may be applied without particular limitation as long as it is composed of a material that can be magnetized by an adjacent unit magnet. Specifically, the magnetizable member may be composed of a ferromagnetic material that increases magnetic flux density when a magnetic field is applied and contains at least one of iron, nickel, cobalt, and chromium.

[0103] For example, the magnetizing member may include a substrate made of iron or stainless steel, or a rod-shaped substrate made of chromium oxide or the like.

[0104] The present invention can strongly implement the strength of magnetism when a magnetic field is applied by configuring the magnetizable member as a ferromagnetic material, and can significantly reduce the magnetic field applied to the electrode current collector (C) transferred between the first magnet part (110a) and the second magnet part (110b) when not exposed to the magnetic field due to the rotation of the adjacent unit magnet.

[0105] These magnetizable members (112a-1 to 112a-n and 112b-1 to 112b-n) may have a total length in the width direction (y-axis direction) of the electrode current collector that is greater than the width of the electrode slurry (ES) applied to the electrode current collector. Specifically, the first magnet portion (110a) and the second magnet portion (110b) may have the same length in the width direction (or y-axis direction) of the electrode current collector. At this time, the total length of the magnetizable members included in each magnet portion may have a length ratio of 101% to 200% of the width of the applied electrode slurry (ES).

[0106] For example, the total length of the magnetizable member included in each magnet portion may have a length ratio in the range of 101% to 180%; 101% to 160%; 125% to 200%; 150% to 200%; 170% to 200%; 110% to 150%; 110% to 130%; 110% to 120%; 105% to 120%; 130% to 150%; 105% to 120%; or 105 to 110% of the width of the electrode slurry (ES).

[0107] In this case, the total length of the magnetizable member may occupy a ratio in the range of 50% or more of the total length of the magnet portion including the magnetizable member. For example, the total length of the magnetizable member may occupy a length ratio in the range of 50% to 99%; 60% to 99%; 70% to 99%; 80% to 99%; 90% to 99%; 50% to 90%; 50% to 80%; 50% to 70%; 60% to 95%; 65% to 90%; or 70% to 90% of the total length of the magnet portion including the magnetizable member.

[0108] When the total length of the magnetizable member has a length ratio that is the same as or similar to the width of the electrode slurry (ES) applied on the electrode current collector (C), it is difficult to sufficiently overcome the intermolecular energy deviation caused by the surface tension of the solvent of the electrode slurry at the edge of the electrode slurry, so that it is difficult for the crystal plane of the electrode active material to be aligned at a high angle with respect to the electrode current collector. However, the present invention allows a strong magnetic field to be applied even at the edge of the electrode slurry by satisfying the above-described range of the total length of the magnetizable member that applies the magnetic field, so that the electrode active material can be uniformly aligned with a high degree of alignment regardless of its position.

[0109] In addition, the magnetic alignment device (1) according to the present invention can control the distance between the first magnet part (110a) and the second magnet part (110b) and the magnetic force of the unit magnet included in each magnet part within a predetermined range in order to reduce the magnetic field influence of the rotated unit magnet when a magnetic field is not applied.

[0110] For example, the magnetic force of the unit magnet included in each magnet section may have a strength in the range of 2,000 G to 8,000 G, and specifically, may have a strength in the range of 2,000 G to 6,000 G; 2,000 G to 4,000 G; 4,000 G to 8,000 G; 3,000 G to 7,000 G; or 4,000 G to 6,000 G.

[0111] In addition, the first magnet portion (110a) and the second magnet portion (110b) may have a separation distance in the range of 10 mm to 1,000 mm so as not to be affected by the magnetic force of the rotated unit magnets when the magnetic field of the magnetic alignment device is not applied, and specifically, 10 mm to 800 mm; 10 mm to 600 mm; 10 mm to 500 mm; 10 mm to 300 mm; 10 mm to 100 mm; 100 mm to 900 mm; 200 mm to 800 mm; 300 mm to 600 mm; 400 mm to 700 mm; 50 mm to 550 mm; 10 mm to 80 mm; 10 mm to 60 mm; 10 mm to 40 mm; 25 mm to 50 mm; 40 mm to 90 mm; 60 mm to 100 mm; Or it may have a spacing distance in the range of 80 mm to 100 mm.

[0112] Furthermore, the above separation distance can be adjusted so that the magnetic field strength of the magnetizable member, represented by the following Equation 1, is greater than the magnetic force of the unit magnet when the magnetic field of the magnetic alignment device is applied:

[0113] [Formula 1]

[0114] y=-a·ln(x)+b

[0115] (In the above equation 1,

[0116] x represents the separation distance between the first magnet part and the second magnet part (unit: mm),

[0117] y represents the magnetic field strength (unit: G) of the magnetizable member when a magnetic field is applied.

[0118] a and b are 5600≤a≤6000 and 26000≤b≤30000).

[0119] Specifically, the above a and b are 5700≤a≤5950 and 27500≤b≤29500.

[0120]

[0121] For example, the separation distance between the first magnet portion (110a) and the second magnet portion (110b) can be adjusted to 30 to 40 mm when the magnetic force of the unit magnet is 5,000 to 6,000 G.

[0122] The present invention can uniformly apply a magnetic field to the electrode slurry transported through the magnetizable member when the magnetic field of the magnetic alignment device is applied by adjusting the distance between the first magnet portion (110a) and the second magnet portion (110b) and the magnetic force of the unit magnet within the above-described range, and can minimize the influence of the magnetic field of the unit magnet when the magnetic field of the magnetic alignment device is not applied.

[0123] In addition, in the magnetic alignment device, the drying unit (120) dries the electrode slurry (S) to which a magnetic field is applied by the first magnet unit (110a) and the second magnet unit (110b) and performs the function of fixing the aligned electrode active material within the slurry.

[0124] The above drying section (120) is formed by including a wall (not shown) that blocks the surrounding area except for the inlet and outlet for introducing and removing electrode sheets coated with electrode slurry (S), and a dryer (not shown) for drying the electrode sheets on the wall on the side from which the electrode sheets coated with electrode slurry are taken out.

[0125] When an electrode sheet (C) coated with electrode slurry (S) enters through the inlet of the drying section (120), it receives energy such as light, wavelength, and heat supplied from the opposite wall. Therefore, it is preferable that the wall be made of an insulating material to prevent heat loss caused by internal energy being transferred to the outside.

[0126] In addition, the drying unit (120) may have a configuration that performs a two-step drying process to maintain the alignment of the carbon-based negative electrode active material contained in the electrode active layer, although the method is not limited thereto. Specifically, the drying unit (120) may include a first dryer that dries the electrode slurry using light and a second dryer that dries the electrode slurry using heat, and the first dryer and the second dryer may operate continuously to dry the electrode slurry.

[0127] The above first dryer is a device for temporarily drying the electrode slurry, and as described above, can irradiate light or wavelengths to the surface of the electrode slurry. Generally, when drying an electrode slurry, it is performed by applying hot air at a high temperature. In this case, the drying time of the electrode slurry takes a long time, and the alignment of the electrode active material in the electrode slurry may be disturbed. In addition, when the temperature of the hot air is increased to solve this problem, the tendency of drying on the surface of the slurry increases, so that a phenomenon (migration) of a binder high in the solvent is concentrated on the surface of the slurry according to the movement of the solvent, and there is a problem that the adhesion strength of the active material layer and the electrode current collector is reduced. The present invention can have a configuration in which the electrode slurry is temporarily dried by irradiating energy in the form of light or wavelengths using the first dryer so as to dry the electrode slurry while maintaining a high degree of alignment of the electrode active material without these problems. Such a first dryer may include, for example, an ultraviolet dryer, a near-infrared dryer, a far-infrared dryer, etc., and specifically, may include a far-infrared dryer that emits energy with a wavelength of 1 μm or more, more specifically, 5 μm or more, 10 μm or more, or 20 μm or more, in order to realize a uniform drying speed of the electrode slurry. Unlike near-infrared dryers or infrared dryers commonly applied in the art, the far-infrared dryer has long light or wavelengths, so it has good energy efficiency and can uniformly apply energy not only to the surface but also to the inside of the electrode slurry, so it has the advantage of being able to increase the adhesive strength between the electrode slurry and the electrode current collector in a short period of time.

[0128] At this time, the first dryer is 50kW / m 2 Up to 1,000 kW / m 2 It can emit energy with a power density of 50 kW / m, specifically 50 kW / m 2 Up to 500kW / m 2 ; 50kW / m 2 Up to 250kW / m 2 of; or 50kW / m 2and 200kW / m 2 Energy can be released with a power density of . The present invention can prevent uneven drying of the active material layer due to excessive power density by controlling the power density of the first dryer within the above range.

[0129] Additionally, the second dryer may apply heat to uniformly and completely dry the electrode slurry pre-dried by light or wavelength. Such a second dryer may include, without limitation, any dryer commonly used in the art, but specifically may include a hot air dryer, a vacuum oven, or the like, used alone or in combination.

[0130]

[0131] The magnetic alignment device according to the present invention, having the above-described configuration, can perform magnetic alignment of electrode active materials within an electrode with high efficiency when manufacturing an electrode for a lithium secondary battery. Furthermore, the magnetic alignment device can easily control whether a magnetic field is applied depending on whether a magnetizable member is magnetized, thereby providing the advantages of excellent workability and high economic efficiency when manufacturing the electrode.

[0132]

[0133] Method for magnetic alignment of electrode active materials within an electrode

[0134] In addition, the present invention,

[0135] It includes a step of applying a magnetic field to the electrode slurry applied to the electrode current collector using a first magnet part and a second magnet part respectively located at the upper and lower portions based on the surface of the electrode current collector,

[0136] The first magnet portion and the second magnet portion each have a structure in which n unit magnets and n-1 magnetizable members are alternately arranged in the width direction of the electrode current collector (where n is an integer from 2 to 20),

[0137] Each unit magnet has a north pole and a south pole, and a method for magnetic alignment of an electrode active material within an electrode is provided in which the poles of the same polarity as those of adjacent unit magnets are controlled to face each other when a magnetic field is applied.

[0138]

[0139] The method for magnetically aligning an electrode active material in an electrode according to the present invention refers to a method for aligning an electrode active material during electrode manufacturing using the magnetic alignment device of the present invention described above.

[0140] That is, the magnetic alignment method includes a step of applying a magnetic field to the electrode slurry applied to the electrode current collector. At this time, the magnetic field application is performed by a magnetic alignment device according to the present invention having a first magnet part and a second magnet part respectively positioned above and below the surface of the electrode current collector.

[0141] The first magnet section and the second magnet section of the magnetic alignment device each have a structure in which n unit magnets and n-1 magnetizable members are alternately arranged in the width direction (or y-axis direction) of the electrode current collector (wherein n is an integer from 2 to 20). Each unit magnet has a N pole and a S pole, and when a magnetic field of the magnetic alignment device is applied, the poles of the same polarity as those of adjacent unit magnets can be arranged to face each other.

[0142] The arrangement of these unit magnets induces magnetization of the magnetizable member arranged between the unit magnets, and the magnetic force induced in the magnetizable member at this time can have a polarity opposite to that of the adjacent unit magnets. For example, if the N pole of the first unit magnet and the N pole of the second unit magnet are arranged to face each other, the first magnetizable member between them can be magnetized to the S pole. In this case, as shown in Fig. 5, since the magnetic field reinforced between the unit magnets acts strongly in the vertical direction based on the surface of each magnet part by the magnetizable member, a strong magnetic field can be applied to the surface of the electrode current collector being transported.

[0143] In addition, the unit magnet included in each magnetic section includes a rotation axis at the boundary between the N pole and the S pole, and the rotation axis can rotate the unit magnet without applying a magnetic field.

[0144] Specifically, the unit magnets included in each magnetic section can individually have a rotation axis. The rotation axis can adjust the position of the poles of the unit magnets so that the magnetic field direction (or magnetic force line) of the unit magnet does not affect the magnetizable member by rotating the unit magnets. Through this, the magnetization of the magnetizable member can be demagnetized. That is, the rotation axis of the unit magnet can stop the application of the magnetic field of the magnetic alignment device by stopping the magnetization of the magnetizable member through a change in the magnetic field position of the unit magnet.

[0145] Furthermore, the magnetic alignment method can control the distance between the first magnet part and the second magnet part and the magnetic force of the unit magnet included in each magnet part within a predetermined range in order to reduce the influence of the rotated unit magnet when a magnetic field is not applied.

[0146] For example, the magnetic force of the unit magnet included in each magnet section may have a strength in the range of 2,000 G to 8,000 G, and specifically, may have a strength in the range of 2,000 G to 6,000 G; 2,000 G to 4,000 G; 4,000 G to 8,000 G; 3,000 G to 7,000 G; or 4,000 G to 6,000 G.

[0147] In addition, the first magnet portion and the second magnet portion may have a separation distance of 10 mm to 1,000 mm so as not to be affected by the magnetic force of the rotated unit magnets when a magnetic field is not applied, and specifically, 10 mm to 800 mm; 10 mm to 600 mm; 10 mm to 500 mm; 10 mm to 300 mm; 10 mm to 100 mm; 100 mm to 900 mm; 200 mm to 800 mm; 300 mm to 600 mm; 400 mm to 700 mm; 50 mm to 550 mm; 10 mm to 80 mm; 10 mm to 60 mm; 10 mm to 40 mm; 25 mm to 50 mm; 40 mm to 90 mm; 60 mm to 100 mm; Or it may have a spacing distance in the range of 80 mm to 100 mm.

[0148] Furthermore, the above separation distance can be adjusted so that the magnetic field strength of the magnetizable member, represented by Equation 1 below, when a magnetic field is applied is greater than the magnetic force of the unit magnet:

[0149] [Formula 1]

[0150] y=-a·ln(x)+b

[0151] (In the above equation 1,

[0152] x represents the separation distance between the first magnet part and the second magnet part (unit: mm),

[0153] y represents the magnetic field strength (unit: G) of the magnetizable member when a magnetic field is applied.

[0154] a and b are 5600≤a≤6000 and 26000≤b≤30000).

[0155] Specifically, the above a and b are 5700≤a≤5950 and 27500≤b≤29500.

[0156]

[0157] For example, the separation distance between the first magnet portion (110a) and the second magnet portion (110b) can be adjusted to 30 to 40 mm when the magnetic force of the unit magnet is 5,000 to 6,000 G.

[0158] The present invention can uniformly apply a magnetic field to the electrode slurry transported through the magnetizable member when the magnetic field of the magnetic alignment device is applied by adjusting the distance between the first magnet portion (110a) and the second magnet portion (110b) and the magnetic force of the unit magnet within the above-described range, and can minimize the influence of the magnetic field of the unit magnet when the magnetic field is not applied.

[0159]

[0160] The magnetic alignment method according to the present invention has the advantage of being able to uniformly apply a magnetic field to the electrode slurry being transported by having the above-described configuration, and also being able to easily control whether or not to apply the magnetic field. In addition, the magnetic alignment method can selectively apply the magnetic field at predetermined intervals along the transport direction of the electrode current collector during electrode manufacturing, and thus has the advantage of being able to manufacture electrodes with a wider range of performance and specifications.

[0161]

[0162] Electrode sheets for lithium secondary batteries

[0163] Furthermore, the present invention,

[0164] An electrode sheet for a lithium secondary battery manufactured by the magnetic alignment method described above is provided.

[0165]

[0166] The electrode sheet for a lithium secondary battery according to the present invention is an electrode sheet manufactured by the magnetic alignment method described above, and may mean a sheet in which an electrode active layer including an electrode active material is provided on an electrode current collector.

[0167] At this time, the electrode sheet may be a negative electrode sheet, and in this case, a carbon-based negative electrode active material that is magnetically aligned and has a crystal plane aligned at a predetermined angle close to vertical with respect to the negative electrode current collector surface may be included in the negative electrode active layer.

[0168] The above electrode sheet can be configured such that the magnetically aligned electrode active material can be distributed throughout the entire area of ​​the electrode active layer, or in some cases, can be distributed only in a predetermined area.

[0169] Specifically, the electrode sheet includes an electrode active layer including an electrode active material on at least one surface of an electrode current collector. Here, when the electrode active layer is divided into regions with a predetermined length ratio along the longitudinal direction of the electrode current collector, a magnetically aligned electrode active material can be alternately distributed in the divided regions.

[0170] For example, the electrode active layer may have a form in which a first region including a magnetically aligned electrode active material and a second region including a non-aligned electrode active material are alternately arranged.

[0171] The length ratio dividing the region of the above electrode active layer may depend on the moving speed of the electrode current collector to which the electrode slurry is applied during electrode manufacturing and the time interval at which the unit magnets included in the first magnet section and the second magnet section rotate. Specifically, the length of the first region including the aligned electrode active material and the second region including the non-aligned electrode active material can be controlled from the time at which a magnetic field is applied / not applied to the moving electrode slurry according to the present invention during electrode manufacturing and the moving speed of the electrode slurry.

[0172] The above electrode sheet has the advantage of being able to easily control the physical properties of the electrode since the length of the region containing the aligned electrode active material and the region containing the non-aligned electrode active material can be easily adjusted.

[0173] There is no particular limitation on the types of lithium secondary batteries to which these electrode sheets can be applied. Specifically, the electrode sheets can be applied to pouch-shaped or prismatic secondary batteries that may include stacked, zigzag, or zigzag-stacked electrode assemblies, or cylindrical or prismatic secondary batteries that include wound electrode assemblies.

[0174] For example, the electrode sheet according to the present invention can be applied to a cylindrical secondary battery including an electrode sheet wound within an electrode assembly.

[0175]

[0176] Hereinafter, the present invention will be described in more detail through examples and experimental examples.

[0177] However, the following examples and experimental examples are only illustrative of the present invention, and the content of the present invention is not limited to the following examples and experimental examples.

[0178]

[0179] Example 1. Preparation of negative electrode for lithium secondary battery

[0180] A carbon-based negative electrode material was prepared by mixing natural graphite and artificial graphite in a 1:1 weight ratio. Styrene butadiene rubber (SBR) was also prepared as a binder, and carboxymethyl cellulose (CMC) was prepared as a thickener.

[0181] A cathode slurry was prepared by mixing 96 wt% of carbon-based cathode active material, 1.5 wt% of carboxymethyl cellulose (CMC), and 2.5 wt% of styrene butadiene rubber (SBR) with water to a solid content of 50%.

[0182] When the cathode slurry was prepared, the prepared cathode slurry (ES) was introduced into the die coater (30) of the electrode manufacturing device (1) as shown in Fig. 1.

[0183] The cathode slurry (ES) fed into the die coater was applied onto a copper foil (thickness: 10 ㎛) being transported roll-to-roll (transport speed: 5 m / min) by the transport section (20), and a magnetic field was applied to the applied cathode slurry (ES). The magnetic field was applied for 9 to 11 seconds using a magnetic alignment device (10) having a structure (n=3) as shown in Fig. 3, and immediately thereafter, the magnetic field was not applied for 9 to 11 seconds by rotating the unit magnets of each magnet section.

[0184] Here, the first magnet part (110a) and the second magnet part (110b) provided in the magnetic alignment device (10) were used, each having a structure in which three unit magnets and two magnetizable members are arranged in the width direction (y-axis direction) of the copper foil (C).

[0185] In addition, the unit magnets of each magnet section were arranged so that the polarity of the end portions was as shown in Fig. 5 when a magnetic field was applied, and were simultaneously rotated 90° clockwise by the rotation axis so that the polarity of the end portions was as shown in Fig. 6 when a magnetic field was not applied. In addition, the magnetizable member included in each magnet section was adjusted so that the total length based on the width direction (y-axis direction) of the copper foil accounted for 60 to 70% of the total length of each magnet section including the magnetizable member, and the length ratio was 105 to 120% based on the width length of the cathode slurry applied to the copper foil.

[0186] In addition, the unit magnet used was a permanent magnet having a cubic shape of 50 mm × 50 mm × 50 mm and exhibiting a magnetic field strength of 5,500±20 G, and the permanent magnets were mounted on each magnet section in a structure in which 5 to 20 were aligned along the transport direction of the electrode current collector. The separation distance between the first magnet section and the second magnet section was adjusted to 60 to 80 mm.

[0187] A negative electrode sheet was obtained by hot-air drying a negative electrode slurry to which a magnetic field was applied, and a negative electrode active layer was formed on a negative electrode current collector. Thereafter, the negative electrode active layer was rolled at 50±1°C, a pressure of 100 to 150 MPa, and a conveying speed of 5 m / s to manufacture a negative electrode for a lithium secondary battery (average thickness of the negative electrode active layer: 180±5 μm).

[0188]

[0189] Comparative Example 1. Manufacturing of a negative electrode for a lithium secondary battery

[0190] A negative electrode for a lithium secondary battery was manufactured using the same method as Example 1, except that the structures of the first and second magnet parts of the magnetic alignment device mounted on the electrode manufacturing device were as shown in Fig. 2.

[0191] At this time, permanent magnets having a magnetic field strength of 5,500±20 G were applied to the magnets of the first magnet section and the second magnet section, and the total length was adjusted to have a length ratio of 105 to 120% based on the width of the cathode slurry in the width direction (y-axis direction) of the copper foil.

[0192] Additionally, the separation distance between the first and second magnet parts was adjusted to 60 to 80 mm, and the total time for which the magnetic field was applied was 18 to 22 seconds.

[0193]

[0194] Comparative Example 2. Manufacturing of a negative electrode for a lithium secondary battery

[0195] A negative electrode for a lithium secondary battery was manufactured using the electrode manufacturing device used in Comparative Example 1, but in the same manner as Example 1, except that the magnetic alignment device was removed from the electrode manufacturing device so that no magnetic field was applied to the negative electrode slurry.

[0196]

[0197] Experimental example.

[0198] In order to evaluate the performance of the magnetic alignment device according to the present invention, the alignment degree (OI) of graphite was measured for the cathodes manufactured in Example 1 and Comparative Examples 1 and 2, respectively.

[0199] Specifically, X-ray diffraction (XRD) spectroscopy was performed on the cathode active layer of the cathodes manufactured in Example 1 and Comparative Examples 1 and 2, respectively, to measure the spectrum. At this time, the X-ray diffraction spectroscopy of the cathode manufactured in Example 1 was measured for the first region to which a magnetic field was applied and the second region to which a magnetic field was not applied. The measurement conditions for the X-ray diffraction (XRD) are as follows:

[0200] - Target: Cu(Kα line) graphite monochromator

[0201] - Slit: Diverging slit = 1 degree, Receiving slit = 0.1 mm, Scatter slit = 1 degree

[0202] - Measurement area: (110) plane: 76.0°<2θ<79.0° / (004) plane: 53.0°<2θ<57.0°.

[0203]

[0204] The average alignment index (OI) of graphite contained in each cathode active layer was calculated from the spectra measured under the above conditions using Equation 2. The results are shown in Table 1:

[0205] [Formula 2]

[0206] OI = I 004 / I 110

[0207] In equation 2,

[0208] I 004 represents the area of ​​the peak representing the (004) crystal plane of the carbon-based negative electrode material in the X-ray diffraction (XRD) spectroscopy analysis of the negative electrode active layer,

[0209] I 110represents the area of ​​the peak representing the (110) crystal plane of the carbon-based negative electrode material in X-ray diffraction (XRD) spectroscopy analysis of the negative electrode active layer.

[0210] OI in the magnetic field applied area OI in the non-magnetic field applied area Example 10.57.8 Comparative example 10.7 Area not included Comparative example 2 Area not included 7.5

[0211]

[0212] As shown in Table 1 above, it can be seen that the magnetic alignment device according to the present invention applies a magnetic field uniformly and can easily control whether or not the magnetic field is applied.

[0213] In addition, it can be seen that the electrode manufactured using the above magnetic alignment device has a magnetic field applied uniformly, and thus the magnetic alignment of the electrode active material is achieved with high efficiency.

[0214] Specifically, the negative electrode of Example 1, in which graphite was magnetically aligned using the magnetic alignment device according to the present invention, exhibited an equivalent average alignment degree (OI) compared to the negative electrode of Comparative Example 1 using a conventional magnetic alignment device equipped with a permanent magnet.

[0215] In addition, the cathode of Example 1 exhibited an average alignment index (OI) similar to that of the cathode of Comparative Example 2, to which no magnetic field was applied, as no magnetic field was applied through the rotation of the unit magnets mounted on each magnet section.

[0216] This means that the unit magnets included in each magnetic part of the magnetic alignment device can indirectly uniformly apply a magnetic field to the electrode slurry by inducing magnetization of the magnetizable member, and that by changing the magnetic field direction of the unit magnet, the magnetic field can be prevented from being applied to the electrode slurry by demagnetizing the magnetizable member.

[0217]

[0218] From these results, it can be seen that the magnetic alignment device according to the present invention can perform magnetic alignment of electrode active materials within an electrode with high efficiency during electrode manufacturing, and has excellent workability and economic feasibility during electrode manufacturing.

[0219]

[0220] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art or having ordinary knowledge in the art that various modifications and changes to the present invention can be made without departing from the spirit and technical scope of the present invention as set forth in the claims to be described below.

[0221] Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the patent claims.

[0222]

[0223] [Explanation of symbols]

[0224] 1: Electrode manufacturing device 10: Magnetic alignment device

[0225] 20: Transfer section 30: Coating section (die coater)

[0226] 110: Magnet section 110a and 110b: Upper magnet section and lower magnet section

[0227] 111a-1~111a-n: Unit magnets of the upper magnet section

[0228] 112a-1~112a-n: Magnetization member of upper magnet part

[0229] 112a-1~112a-n: Rotation axis of unit magnet included in the upper magnet section

[0230] 111b-1~111b-n: Unit magnets of the lower magnet section

[0231] 112b-1~112b-n: Magnetization member of lower magnet section

[0232] 113b-1~113b-n: Rotation axis of unit magnet included in lower magnet section

[0233] 114a and 114b: Fixed guides

[0234] 115: Base frame 120: Drying section

[0235] 1 st MG: Upper magnet section

[0236] 2 nd MG: Lower magnet section

[0237] C: Whole house

[0238] ES: Electrode slurry

[0239] M: magnetic field direction

[0240] x: transport direction of electrode collector

[0241] y: direction perpendicular to the electrode current collector transport direction / width direction of the electrode current collector

[0242] z: direction perpendicular to the electrode collector surface

Claims

1. It includes a first magnet part and a second magnet part, which are respectively positioned above and below the surface of the electrode collector along the transport direction of the electrode collector to which the electrode slurry is applied, and apply a magnetic force. The first magnet portion and the second magnet portion each have a structure in which n unit magnets and n-1 magnetizable elements are alternately arranged in the width direction of the electrode current collector (where n is an integer from 2 to 20). The above unit magnet has a N pole and a S pole, and is arranged so that the poles of the same polarity as those of adjacent unit magnets face each other when a magnetic field is applied. The above magnetization element is a magnetic alignment device that is magnetized with a different polarity from the adjacent unit magnets.

2. In paragraph 1, A magnetic alignment device in which the magnetizable member of the first magnetic portion is magnetized with a different polarity from the magnetizable member of the second magnetic portion when a magnetic field is applied.

3. In paragraph 1, A magnetic alignment device in which each of the above n unit magnets includes a rotation axis at the boundary between the N pole and the S pole, and in which each rotation axis rotates in the same direction so that the N pole or the S pole of each unit magnet faces the electrode current collector when no magnetic field is applied.

4. In paragraph 3, The first magnet part and the second magnet part are, A base frame providing a space for positioning n unit magnets and n-1 magnetizable elements included in each magnetic section at the top and bottom of the electrode current collector being transported; A fixed guide that is supported on the above base frame and fixes n-1 magnetizable members, and A magnetic alignment device including a rotation unit that is supported on the base frame and rotates a rotation axis included in n unit magnets.

5. In paragraph 1, The above magnetization absence is a magnetic alignment device in which the total length of the electrode current collector in the width direction has a ratio in the range of 101% to 200% of the width of the electrode slurry.

6. In paragraph 1, A magnetic alignment device in which the first magnet portion and the second magnet portion have a separation distance ranging from 10 mm to 1,000 mm.

7. In paragraph 1, The above unit magnet is a magnetic alignment device exhibiting a magnetic force in the range of 2,000 G to 8,000 G.

8. In paragraph 1, A magnetic alignment device, characterized in that the above unit magnets are permanent magnets.

9. In paragraph 1, The above magnetization element is a magnetic alignment device composed of a ferromagnetic material containing at least one of iron, nickel, cobalt, and chromium.

10. A step of applying a magnetic field to the electrode slurry applied to the electrode current collector by using the first magnet part and the second magnet part respectively located at the upper and lower portions based on the surface of the electrode current collector, The first magnet portion and the second magnet portion each have a structure in which n unit magnets and n-1 magnetizable elements are alternately arranged in the width direction of the electrode current collector (where n is an integer from 2 to 20). A method for magnetic alignment of electrode active materials within an electrode, wherein each unit magnet has a north pole and a south pole, and when a magnetic field is applied, the poles of the same polarity as those of adjacent unit magnets are arranged to face each other.

11. In paragraph 10, A magnetic alignment method in which the magnetizable member of the first magnet portion is magnetized with a different polarity from the magnetizable member of the second magnet portion when a magnetic field is applied.

12. In paragraph 10, A magnetic alignment method in which the above n unit magnets each include a rotation axis at the boundary between the N pole and the S pole, and when no magnetic field is applied, the N pole or the S pole of the unit magnets rotates in the same direction so as to face the electrode collector.

13. In paragraph 10, A magnetic alignment method in which the first magnet portion and the second magnet portion are spaced apart so that the magnetic field strength of the magnetizable member represented by Equation 1 below is greater than the magnetic force of the unit magnet when a magnetic field is applied: [Formula 1] y=-a·ln(x)+b (In the above equation 1, x represents the separation distance between the first magnet part and the second magnet part (unit: mm), y represents the magnetic field strength (unit: G) of the magnetizable element when a magnetic field is applied. a and b are 5600≤a≤6000 and 26000≤b≤30000).

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