Negative electrode material, manufacturing method therefor, and secondary battery comprising same

Abstract

Disclosed are: a negative electrode material that can be prevented from expanding toward a positive electrode material and thus can prevent explosions caused by a short circuit between the positive electrode material and the negative electrode material; a manufacturing method therefor; and a secondary battery comprising same. The negative electrode material includes a negative electrode current collector, multiple first negative electrode active material bars, and multiple second negative electrode active material bars. The multiple first negative electrode active material bars are attached to one surface of the negative electrode current collector. The multiple second negative electrode active material bars are attached to upper portions of the first negative electrode active material bars. The first negative electrode active material bars and the second negative electrode active material bars are arranged in directions crossing each other.

Description

Negative electrode material, method for manufacturing the same, and secondary battery including the same

[0001] The present invention relates to a negative electrode material, a method for manufacturing the same, and a secondary battery including the same, and more specifically, to a negative electrode material capable of reducing the risk of explosion, a method for manufacturing the same, and a secondary battery including the same.

[0002] Today, with the advancement of the information age, mobile electronic devices owned by individuals are becoming widely used. These mobile electronic devices inevitably require batteries to operate.

[0003] In the past, primary batteries, such as manganese batteries and alkaline batteries, were mainly used, which were used once and discarded when discharged. However, recently, secondary batteries, which can be recharged after discharge and used repeatedly, are being widely used instead of primary batteries, which are disadvantageous in terms of environmental pollution and cost of discarded batteries.

[0004] These secondary batteries typically consist of a cathode, anode, electrolyte, and separator. Among these, the cathode and anode are the most crucial materials that determine the battery's capacity, lifespan, and charging speed. The cathode, as a lithium-ion source, determines the battery's capacity and average voltage, while the anode determines the charging speed and lifespan.

[0005] When charging, the lithium ions in the positive electrode material move toward the negative electrode material, and the negative electrode active material stores these lithium ions. When discharging, the lithium ions in the negative electrode active material move toward the positive electrode material.

[0006] At this time, when the negative electrode active material stores lithium ions, the volume increases, and conversely, when it releases them, the volume decreases. If the number of charge and discharge cycles increases in this way, the secondary battery may be damaged, increasing the risk of explosion.

[0007] [Prior Art Literature]

[0008] [Patent Document]

[0009] (Patent Document 1) Republic of Korea Publication No. 10-2022-0167669

[0010] Accordingly, the problem that the present invention seeks to solve is to provide a negative electrode material that can reduce the risk of secondary battery explosion.

[0011] Another problem that the present invention seeks to solve is to provide a method for manufacturing such a negative electrode material.

[0012] Another problem that the present invention seeks to solve is to provide a secondary battery including such a negative electrode material.

[0013] According to an exemplary embodiment of the present invention for solving these problems, a negative electrode material includes a negative electrode current collector plate, a plurality of first negative electrode active material bars, and a plurality of second negative electrode active material bars. The plurality of first negative electrode active material bars are attached to one surface of the negative electrode current collector plate. The plurality of second negative electrode active material bars are attached to upper portions of the first negative electrode active material bars. At this time, the first negative electrode active material bars and the second negative electrode active material bars are arranged in a direction intersecting each other.

[0014] As an example, the first negative electrode active material bar and the second negative electrode active material bar may be arranged in a direction perpendicular to each other.

[0015] As an example, a plurality of plate-shaped negative electrode material flakes are arranged in a form standing upright with respect to the one surface inside the first negative electrode material bar and the second negative electrode material bar.

[0016] As an example, the plate-shaped negative electrode material flake may include at least one of silicon, tin, antimony, and graphene.

[0017] As an example, the negative electrode collector may include copper.

[0018] As an example, the plurality of first negative electrode active material bars and second negative electrode active material bars may be attached to the negative electrode current collector plate by a mixture of a polymer resin and a conductor or a conductive polymer resin.

[0019] As an example, the polymer resin may include any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), and silicone rubber.

[0020] As an example, the cross sections of the first negative electrode active material bar and the second negative electrode active material bar may be rectangular.

[0021] As an example, among the rectangular cross sections of the first negative electrode active material bar and the second negative electrode active material bar, the long side may be arranged toward the negative electrode current collector plate.

[0022] As an example, at least one of the first negative electrode active material bar and the second negative electrode active material bar may be in contact with each other, or may be in contact with a mixture of a polymer resin and a conductor or a conductive polymer resin therebetween.

[0023] A method for manufacturing a negative electrode material according to an exemplary embodiment of the present invention includes a step of forming a slurry by mixing plate-shaped negative electrode material flakes, a binder, and a solvent, a step of extruding the slurry and cutting it into a predetermined length to form a plurality of first negative electrode material active material bars and a plurality of second negative electrode material active material bars, and a step of attaching the plurality of first negative electrode material active material bars extending in a first direction in a first layer and the plurality of second negative electrode material bars extending in a second direction different from the first direction in a second layer to a negative electrode current collector plate.

[0024] As an example, the method for manufacturing a negative electrode material may further include a step of performing a pressing process to align the plate-shaped negative electrode material flakes so that they lie down before attaching the first negative electrode material active material bar and the second negative electrode material active material bar to the negative electrode current collector.

[0025] As an example, the pressing process may be performed by passing between a pair of rollers that rotate in opposite directions.

[0026] As an example, the method for manufacturing a negative electrode material may further include a step of drying the first negative electrode active material bar and the second negative electrode active material bar to remove a solvent before performing a pressing process on the negative electrode active material bar.

[0027] As an example, the cross-sections of the first negative electrode active material bar and the second negative electrode active material bar may be rectangular.

[0028] In one embodiment, the step of attaching a plurality of first negative electrode active material bars extending in a first direction in a first layer and a plurality of second negative electrode active material bars extending in a second direction different from the first direction in a second layer to a negative electrode current collector may include the step of attaching the plurality of first negative electrode active material bars extending in the first direction to one surface of the negative electrode current collector, and the step of attaching the plurality of second negative electrode active material bars extending in the second direction on top of the plurality of first negative electrode active material bars.

[0029] Alternatively, the step of attaching the plurality of first negative electrode active material bars extending in a first direction in the first layer and the plurality of second negative electrode active material bars extending in a second direction different from the first direction in the second layer to the negative electrode current collector may include the steps of arranging the plurality of first negative electrode active material bars extending in the first direction, arranging the plurality of second negative electrode active material bars extending in the second direction on top of the plurality of first negative electrode active material bars, forming a negative electrode active material plate by attaching the plurality of first negative electrode active material bars and the plurality of second negative electrode active material bars, and attaching the negative electrode active material plate to the negative electrode current collector.

[0030] As an example, the step of forming a negative electrode active material plate by attaching the plurality of first negative electrode active material bars and the plurality of second negative electrode active material bars may be performed by pressurizing the plurality of first negative electrode active material bars and the plurality of second negative electrode active material bars at high temperatures.

[0031] As an example, when pressurizing at high temperature, the temperature may be in the range of 130°C to 200°C.

[0032] Preferably, during the high temperature pressurization, the temperature may be in the range of 150°C to 170°C.

[0033] As an example, the binder may include any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), PVDF (polyvinylidene fluoride), and PTFE (polytetrafluoroethylene).

[0034] As an example, the solvent may include water or NMP (N-Methyl-2-Pyrrolidone).

[0035] A secondary battery according to an exemplary embodiment of the present invention comprises the anode material, the cathode material, the electrolyte, and the separator described above. The cathode material is disposed spaced apart from the cathode material. The electrolyte is disposed between the cathode and the anode materials. The separator is disposed within the electrolyte to separate the cathode and the anode.

[0036] In one embodiment, the positive electrode material includes a positive electrode current collector plate and a positive electrode active material layer. The positive electrode current collector plate has a plate shape. The positive electrode active material layer is formed on one surface of the positive electrode current collector plate and is formed by mixing a positive electrode active material, a conductive material, and a binder.

[0037] As an example, the cathode active material may be LiCoO2, LiNiCoMnO2, LiMnO4, LZO-NCM (LiNi coated with Li2O-ZrO2). X Co y Mn z O2), NMC, and may include at least one of them.

[0038] As an example, the conductive material may include at least one of carbon black, acetylene black, VGCF (Vapor grown carbon fiber), CNT, and graphene.

[0039] In this way, according to the negative electrode material of the present invention, since the negative electrode active material bars are arranged in a cross pattern, the separation of the negative electrode active material bars from each other during expansion can be reduced.

[0040] In addition, since the plate-shaped negative electrode material flakes are arranged in an upright shape with respect to the surface of the negative electrode collector, even if they store lithium ions and expand, they expand in a direction parallel to the surface of the negative electrode collector, preventing them from expanding toward the positive electrode material, thereby preventing an explosion due to a short circuit between the positive electrode material and the negative electrode material.

[0041] FIG. 1 is a plan view illustrating a cathode material according to an exemplary embodiment of the present invention.

[0042] Fig. 2 is a cross-sectional view taken along the cutting line II-II' shown in Fig. 1.

[0043] Figure 3 is a flowchart illustrating a method for manufacturing a negative electrode material according to an exemplary embodiment of the present invention.

[0044] Figure 4 is a schematic diagram illustrating step S120 illustrated in Figure 3.

[0045] Figure 5 is a cross-sectional view of a negative electrode active material bar formed by passing through the discharge port of the syringe illustrated in Figure 4.

[0046] Figure 6 is a schematic diagram illustrating step S140 illustrated in Figure 3.

[0047] Fig. 7 is a cross-sectional view showing a negative electrode active material bar formed by passing through the roller of Fig. 6.

[0048] Figure 8 is a schematic diagram of a secondary battery including the negative electrode material illustrated in Figure 1.

[0049] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Throughout the description of each drawing, similar reference numerals have been used to designate similar components. In the accompanying drawings, the dimensions of structures may be exaggerated to enhance clarity of the present invention.

[0050] While terms like "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

[0051] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" 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. In addition, the meaning of A and B being "connected" or "coupled" includes a case where, in addition to A and B being directly connected or coupled, another component C is included between A and B so that A and B are connected or coupled.

[0052] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be construed in an idealized or overly formal sense unless explicitly defined herein. Furthermore, in the claims for method inventions, the order of the steps may be interchanged, unless the order of the steps is explicitly stated.

[0053] Additionally, the configurations individually described in each embodiment may also be applied in other embodiments.

[0054] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

[0055] FIG. 1 is a plan view illustrating a negative electrode material according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the cutting line II-II' illustrated in FIG. 1.

[0056] Referring to FIGS. 1 and 2, a negative electrode material (1000) according to an exemplary embodiment of the present invention includes a negative electrode current collector plate (1100) and a plurality of negative electrode active material bars (1200).

[0057] The negative electrode collector plate (1100) has a plate shape, and its planar shape can be arbitrarily changed. As an example, the negative electrode collector plate (1100) may have a rectangular planar shape. For example, the negative electrode collector plate (1100) may include copper.

[0058] The above-described plurality of negative electrode active material bars (1200) include a plurality of first negative electrode active material bars (1200a) and a plurality of second negative electrode active material bars (1200b).

[0059] The above-described plurality of first negative electrode active material bars (1200a) are attached to one surface of the negative electrode current collector (1100). In addition, the above-described plurality of second negative electrode active material bars (1200b) are attached to the upper portions of the above-described plurality of first negative electrode active material bars (1200a). At this time, the first negative electrode active material bars (1200a) and the second negative electrode active material bars (1200b) are arranged in a direction intersecting with each other. Preferably, the first negative electrode active material bars (1200a) and the second negative electrode active material bars (1200b) may be arranged in a direction perpendicular to each other. In this way, by intersecting the first negative electrode active material bars (1200a) and the second negative electrode active material bars (1200b), the separation of the negative electrode active material bars due to their pushing each other during expansion can be reduced. In more detail, the negative electrode active material bar expands in the width direction of the negative electrode active material bar (1200) when lithium ions are absorbed by the plate-shaped negative electrode flakes described later, and the first negative electrode active material bar (1200a) and the second negative electrode active material bar (1200b) intersect with each other to fix each other.

[0060] Meanwhile, inside the first negative electrode active material bar (1200a) and the plurality of second negative electrode active material bars (1200b), a plurality of plate-shaped negative electrode flakes (1210) are arranged in an upright shape based on the one surface of the negative electrode current collector (1100).

[0061] In this way, when the plate-shaped negative electrode material flakes (1210) are arranged in an upright shape with respect to the surface of the negative electrode collector (1100), even if the plate-shaped negative electrode material flakes (1210) store lithium ions and expand, they expand in a direction parallel to the surface of the negative electrode collector (1100) (i.e., in the X-axis or Z-axis direction). Therefore, as illustrated in FIG. 8, the negative electrode material (1000) can be prevented from expanding toward the positive electrode material (2000) (i.e., in the Y-direction), thereby preventing an explosion due to a short circuit between the positive electrode material and the negative electrode material.

[0062] As an example, the plate-shaped negative electrode material flake (1210) may include at least one of silicon, tin, antimony, and graphene.

[0063] As an example, the plurality of negative electrode active material bars (1200) may be in contact with each other or may be in contact with a bonding member (1300) therebetween.

[0064] In addition, the plurality of first negative electrode active material bars (1200a) may be attached to the negative electrode current collector (1100) through a bonding member (1300). In addition, the plurality of first negative electrode active material bars (1200a) and the plurality of second negative electrode active material bars (1200b) may be attached to each other through the bonding member (1300). Alternatively, the plurality of first negative electrode active material bars (1200a) may be directly attached to the negative electrode current collector (1100) through thermocompression bonding. In addition, the plurality of first negative electrode active material bars (1200a) and the plurality of second negative electrode active material bars (1200b) may be attached to each other through thermocompression bonding.

[0065] Meanwhile, the above-mentioned bonding member (1300) may include a mixture of a polymer resin and a conductor or a conductive polymer resin.

[0066] As an example, the polymer resin may include any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), and silicone rubber. In the present example, the bonding member that bonds the plurality of negative electrode active material bars (1200) to each other and the bonding member that attaches the plurality of first negative electrode active material bars (1200a) to the negative electrode current collector (1100) are the same, but may be different from each other.

[0067] As an example, the cross-section of the negative electrode active material bar (1200) may be a rectangle with a long side length of d1 and a short side length of d2.

[0068] As an example, among the rectangular cross-sections of the negative electrode active material bar (1200), the long side may be attached to the negative electrode current collector (1100). In this case, when the long side is in contact with the negative electrode current collector (1100), the frequency with which the plate-like negative electrode material flakes come into contact with the negative electrode current collector (1100) can be increased.

[0069] Figure 3 is a flowchart illustrating a method for manufacturing a negative electrode material according to an exemplary embodiment of the present invention.

[0070] Referring to FIG. 3, according to a method for manufacturing a negative electrode material according to an exemplary embodiment of the present invention, first, a plate-shaped negative electrode material flake, a binder, and a solvent are mixed to form a slurry (step S110). In one embodiment, the plate-shaped negative electrode material flake may include at least one of silicon, tin, antimony, and graphene. In one embodiment, the binder may include one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), PVDF (polyvinylidene fluoride), and PTFE (polytetrafluoroethylene). In one embodiment, the solvent may include water or NMP (N-Methyl-2-Pyrrolidone).

[0071] Thereafter, the slurry is extruded and cut into a certain length to form a plurality of first and second negative electrode active material bars (step S120).

[0072] Figure 4 is a schematic diagram illustrating step S120 illustrated in Figure 3.

[0073] Referring to Fig. 4, a slurry (SR) is mixed with plate-shaped negative electrode material flakes, a binder, and a solvent, and injected into a syringe (S), a piston (P) is pressurized to discharge, and the slurry is cut to a certain length to form a negative electrode active material bar (B). For example, the discharge port of the syringe (S) is configured to have a square cross-section, so that the manufactured negative electrode active material bar (B) can have a square cross-section.

[0074] Figure 5 is a cross-sectional view of a negative electrode active material bar formed by passing through the discharge port of the syringe illustrated in Figure 4.

[0075] Referring to Fig. 5, the shape of the discharge port of the syringe (S) of Fig. 4 is formed, for example, as a rectangle, so that the negative electrode active material bar (B) formed with the discharged slurry has a rectangular cross-section with one side length D1 and the other side length D2. At this time, the plate-shaped negative electrode material flakes (1210) are roughly aligned as shown by the pressure and gravity being extruded inside the negative electrode active material bar (B).

[0076] Referring again to FIG. 3, the slurry is extruded and cut into a predetermined length to form a negative electrode active material bar (step S120), and then a pressing process is performed on the bar to align the plate-shaped negative electrode material flakes so that they are completely laid down, thereby forming a negative electrode active material bar (step S140). This pressing process is not essential, but it is preferable to perform the pressing process to completely align the plate-shaped negative electrode material flakes.

[0077] Figure 6 is a schematic diagram illustrating step S140 illustrated in Figure 3.

[0078] Referring to Fig. 6, the pressing process can be performed, for example, by passing the material between a pair of rollers (R) that rotate in opposite directions. For example, the pair of rollers (R) are spaced apart from each other by a length of d1, so that a bar having a long side length of D1 is pressed, thereby manufacturing a rectangular negative electrode active material bar having a long side length of d1.

[0079] Fig. 7 is a cross-sectional view showing a negative electrode active material bar formed by passing through the roller of Fig. 6.

[0080] Referring to Fig. 7, the negative electrode active material bar (1200) formed by passing through the roller has a rectangular cross-sectional shape with a long side length of d1 and a short side length of d21, and at this time, the plate-shaped negative electrode material flakes (1210) are pressed and arranged parallel to the short side.

[0081] In this embodiment, pressure is applied through a roller, but it is not limited thereto, and pressure may be applied using a plate, and various pressurization methods may be applied.

[0082] Again, referring to FIG. 3, a plurality of first negative electrode active material bars extending in a first direction in a first layer and a plurality of second negative electrode active material bars extending in a second direction different from the first direction in a second layer are attached to a negative electrode current collector (step S150). At this time, as described above, the first negative electrode active material bars may be attached to the negative electrode current collector through a bonding member. Additionally, the second negative electrode active material bars may be attached to the first negative electrode active material bars through a bonding member. Alternatively, the first and second negative electrode active material bars may be directly attached to each other through a thermocompression bonding process.

[0083] More specifically, the step (S150) of attaching the plurality of first negative electrode active material bars extending in a first direction in the first layer and the plurality of second negative electrode active material bars extending in a second direction different from the first direction in the second layer to a negative electrode current collector may include the step of attaching the plurality of first negative electrode active material bars extending in the first direction to one surface of the negative electrode current collector, and the step of attaching the plurality of second negative electrode active material bars extending in the second direction on top of the plurality of first negative electrode active material bars. That is, first, the first negative electrode active material bars may be attached to the negative electrode current collector, and then the second negative electrode active material bars may be attached on top of the first negative electrode active material bars.

[0084] In contrast, the step (S150) of attaching the plurality of first negative electrode active material bars extending in a first direction in the first layer and the plurality of second negative electrode active material bars extending in a second direction different from the first direction in the second layer to the negative electrode current collector may include the steps of arranging the plurality of first negative electrode active material bars extending in the first direction, arranging the plurality of second negative electrode active material bars extending in the second direction on top of the plurality of first negative electrode active material bars, forming a negative electrode active material plate by attaching the plurality of first negative electrode active material bars and the plurality of second negative electrode active material bars, and attaching the negative electrode active material plate to the negative electrode current collector. That is, the first negative electrode active material bars and the second negative electrode active material bars may be attached to each other in an intersecting direction and then attached to the negative electrode current collector.

[0085] As an example, the step of forming a negative electrode active material plate by attaching the plurality of first negative electrode active material bars and the plurality of second negative electrode active material bars may be performed by pressurizing the plurality of first negative electrode active material bars and the plurality of second negative electrode active material bars at high temperatures.

[0086] As an example, during the high-temperature pressurization, the temperature may be in the range of 130°C to 200°C. Preferably, during the high-temperature pressurization, the temperature may be in the range of 150°C to 170°C. If the temperature is lower than 130°C, the adhesive strength decreases, and if the thermal compression is too strong at 200°C or higher, the erected negative electrode material flakes will lie down again.

[0087] Meanwhile, before performing the pressing process on the bar in FIG. 3 (step S140), a step of drying the bar to remove the solvent (step S130) may be further performed.

[0088] Alternatively, the drying process may be performed after the pressing process (step S140), or semi-drying may be performed before the pressing process (step S140), and complete drying may be performed after the pressing process (step S140).

[0089] Figure 8 is a schematic diagram of a secondary battery including the negative electrode material illustrated in Figure 1.

[0090] Referring to FIG. 8, a secondary battery according to an exemplary embodiment of the present invention includes a negative electrode material (1000) manufactured by any one of the methods described above, a positive electrode material (2000) disposed spaced apart from the negative electrode material (1000), an electrolyte (EL) disposed between the negative electrode material (1000) and the positive electrode material (2000), and a separator (SM) disposed on the electrolyte (EL) to separate the positive electrode and the negative electrode.

[0091] For example, the positive electrode material (2000) may include a positive electrode current collector (2100) in a plate shape, and a positive electrode active material (2200) formed on one surface of the positive electrode current collector (2100) and containing a mixture of a positive electrode active material, a conductive material, and a binder.

[0092] For example, the positive electrode active material may be LiCoO2, LiNiCoMnO2, LiMnO4, LZO-NCM (LiNi coated with Li2O-ZrO2).X Co y Mn z O2), NMC, and may include at least one of them.

[0093] For example, the conductive material may include at least one of carbon black, acetylene black, VGCF (Vapor grown carbon fiber), CNT, and graphene.

[0094] For example, the positive electrode collector (2100) may include aluminum.

[0095] In this way, according to the negative electrode material of the present invention, since the negative electrode active material bars are arranged in a cross pattern, the separation of the negative electrode active material bars from each other during expansion can be reduced.

[0096] In addition, since the plate-shaped negative electrode material flakes are arranged in an upright shape with respect to the surface of the negative electrode collector, even if they store lithium ions and expand, they expand in a direction parallel to the surface of the negative electrode collector, preventing them from expanding toward the positive electrode material, thereby preventing an explosion due to a short circuit between the positive electrode material and the negative electrode material.

[0097] Although the detailed description of the present invention described above has been described with reference to preferred embodiments of the present invention, it will be understood by those skilled in the art or having ordinary knowledge in the art that various modifications and changes can be made to the present invention without departing from the spirit and technical scope of the present invention as set forth in the claims to be described later.

Claims

1. Negative collector plate; A plurality of first negative electrode active material bars attached to one surface of the negative electrode current collector; and A plurality of second negative electrode active material bars attached to the upper portion of the first negative electrode active material bar; Including, A negative electrode material characterized in that the first negative electrode active material bar and the second negative electrode active material bar are arranged in a direction intersecting each other.

2. In paragraph 1, A negative electrode material characterized in that the first negative electrode active material bar and the second negative electrode active material bar are arranged in a direction perpendicular to each other.

3. In paragraph 1, A negative electrode material characterized in that a plurality of plate-shaped negative electrode material flakes are arranged in an upright shape based on the first negative electrode material active material bar and the second negative electrode material active material bar.

4. In paragraph 3, The above plate-shaped negative electrode material flake is characterized in that it contains at least one of silicon, tin, antimony, and graphene.

5. In paragraph 1, A cathode material characterized in that the above cathode current collector plate comprises copper.

6. In paragraph 1, A negative electrode material characterized in that the plurality of first negative electrode active material bars and second negative electrode active material bars are attached to the negative electrode current collector by a mixture of a polymer resin and a conductor or a conductive polymer resin.

7. In paragraph 6, The above polymer resin is a cathode material characterized in that it includes any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), and silicone rubber.

8. In paragraph 1, A negative electrode material characterized in that the cross sections of the first negative electrode active material bar and the second negative electrode active material bar are rectangular.

9. In paragraph 8, A negative electrode material characterized in that the long side of the rectangular cross-section of the first negative electrode active material bar and the second negative electrode active material bar is arranged toward the negative electrode current collector plate.

10. In paragraph 1, A negative electrode material characterized in that at least one of the first negative electrode active material bar and the second negative electrode active material bar is in contact with each other, or is in contact with a mixture of a polymer resin and a conductor, or with a conductive polymer resin therebetween.

11. A step of forming a slurry by mixing plate-shaped negative electrode material flakes, a binder, and a solvent; A step of extruding the above slurry and cutting it into a predetermined length to form a plurality of first negative electrode active material bars and a plurality of second negative electrode active material bars; and A step of attaching a plurality of first negative electrode active material bars extending in a first direction on a first layer and a plurality of second negative electrode active material bars extending in a second direction different from the first direction on a second layer to a negative electrode current collector; A method for manufacturing a cathode material including:

12. In paragraph 11, Before attaching the first negative electrode active material bar and the second negative electrode active material bar to the negative electrode current collector, A step of performing a pressing process to align the plate-shaped negative electrode material flakes so that they lie down; A method for manufacturing a cathode material, characterized in that it further includes:

13. In paragraph 12, A method for manufacturing a negative electrode material, characterized in that the above pressing process is performed by passing the material between a pair of rollers that rotate in opposite directions.

14. In paragraph 12, Before performing a pressing process on the negative electrode active material bar, a step of drying the first negative electrode active material bar and the second negative electrode active material bar to remove the solvent; A method for manufacturing a cathode material, characterized in that it further includes:

15. In paragraph 11, A method for manufacturing a negative electrode material, characterized in that the cross sections of the first negative electrode active material bar and the second negative electrode active material bar are rectangular.

16. In paragraph 11, The step of attaching a plurality of first negative electrode active material bars extending in a first direction on the first layer and a plurality of second negative electrode active material bars extending in a second direction different from the first direction on the second layer to a negative electrode current collector plate is as follows: A step of attaching a plurality of first negative electrode active material bars extending in the first direction to one surface of the negative electrode collector plate; and A step of attaching a plurality of second negative electrode active material bars extending in a second direction to the upper portion of the plurality of first negative electrode active material bars; A method for manufacturing a cathode material, characterized by including:

17. In paragraph 11, The step of attaching a plurality of first negative electrode active material bars extending in a first direction on the first layer and a plurality of second negative electrode active material bars extending in a second direction different from the first direction on the second layer to a negative electrode current collector plate is as follows: A step of arranging a plurality of first negative electrode active material bars extending in the first direction; A step of arranging a plurality of second negative electrode active material bars extending in the second direction on top of the plurality of first negative electrode active material bars; and A step of forming a negative electrode active material plate by attaching the plurality of first negative electrode active material bars and the plurality of second negative electrode active material bars; and A step of attaching the negative electrode active material plate to the negative electrode current collector; A method for manufacturing a cathode material, characterized by including:

18. In paragraph 17, The step of forming a negative electrode active material plate by attaching the plurality of first negative electrode active material bars and the plurality of second negative electrode active material bars is as follows: A method for manufacturing a negative electrode material, characterized in that it is performed by high-temperature and pressurizing the plurality of first negative electrode active material bars and the plurality of second negative electrode active material bars.

19. In paragraph 18, A method for manufacturing a cathode material, characterized in that, during the high-temperature pressurization, the temperature is in the range of 130°C to 200°C.

20. In paragraph 19, A method for manufacturing a cathode material, characterized in that, during the high-temperature pressurization, the temperature is in the range of 150°C to 170°C.

21. In paragraph 11, A method for manufacturing a negative electrode material, characterized in that the binder comprises any one of SBR (styrene butadiene rubber), CMC (carboxy methylcellulose), PVDF (polyvinylidene fluoride), and PTFE (polytetrafluoroethylene).

22. In paragraph 11, A method for manufacturing a negative electrode material, characterized in that the solvent comprises water or NMP (N-Methyl-2-Pyrrolidone).

23. Negative electrode material according to Article 1; A cathode material disposed spaced apart from the cathode material; An electrolyte disposed between the cathode material and the anode material; and A separator disposed in the electrolyte to separate the positive and negative electrodes; A secondary battery containing:

24. In paragraph 23, The above cathode material is, a positive electrode current collector in the shape of a plate; and A positive electrode active material layer formed on one surface of the positive electrode current collector, wherein the positive electrode active material, conductive material, and binder are mixed; A secondary battery characterized by including:

25. In paragraph 24, The above cathode active materials are LiCoO2, LiNiCoMnO2, LiMnO4, LZO-NCM (LiNi coated with Li2O-ZrO2) X Co y Mn z A secondary battery characterized by including at least one of O2) and NMC.

26. In paragraph 24, A secondary battery characterized in that the above conductive material comprises at least one of carbon black, acetylene black, VGCF (Vapor grown carbon fiber), CNT, and graphene.

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