Method for manufacturing a positive electrode plate using a dry annular carbon compact

Abstract

The present invention relates to a method for manufacturing an anode electrode plate using a dry annular carbon molded body. By placing a dry annular carbon molded body, formed into an annular structure, on each side of a porous current collector and then simultaneously compressing both sides to manufacture the anode electrode plate, the internal porosity and density distribution of the anode electrode plate can be uniformly controlled, and thickness variation can be minimized.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing an anode electrode plate using a dry annular carbon molded body, and more specifically, to a method for manufacturing an anode electrode plate using a dry annular carbon molded body that can uniformly control the internal porosity and density distribution of the anode electrode plate and minimize thickness variation by placing a dry annular carbon molded body formed into an annular structure on each side of a porous current collector and then simultaneously compressing both sides. Background Technology

[0002] The performance of lithium primary batteries is generally determined by the structural uniformity of the positive electrode plate, pore distribution, adhesion to the current collector, electrode density, etc.

[0003] Most lithium battery positive electrode plates are manufactured through a wet coating process in which an active material, a conductive material, and a binder are dispersed in a solvent to form a slurry, which is then applied to the surface of a metal current collector and subjected to drying and roll rolling.

[0004] However, conventional wet coating processes have high process complexity due to the use of solvents and require large-scale facilities for drying and solvent recovery. In addition, as the solvent evaporates during the drying process, the binder and conductive material move within the electrode, and non-uniformity of the pore structure is prone to occur in the electrode thickness direction and in-plane direction. Consequently, the pore size distribution within the electrode becomes non-uniform, and localized overcrowded or undercrowded regions are formed, leading to increased ion diffusion resistance and causing electrode resistance deviation and reduced lifespan.

[0005] In addition, variations in coating thickness, roll marks, and surface defects are prone to occur due to changes in slurry viscosity, poor dispersion, and sedimentation, which leads to variations in electrode performance and reduced yield. In particular, when attempting to implement high-porosity electrodes or thick electrodes, there was a problem where stable manufacturing was difficult due to structural collapse and reduced adhesion caused by drying shrinkage.

[0006] In order to overcome the problems of such wet processes, solvent-free dry powder-based electrode manufacturing technology is being researched recently.

[0007] However, the method of directly applying dry powder onto the current collector had the disadvantage that static electricity was easily generated due to the characteristics of the fine powder, causing the powder to adhere to equipment or materials or scatter into the air, which worsened the working environment and increased material loss.

[0008] Furthermore, because it is difficult to uniformly control the in-plane distribution of the powder, the density and porosity within the electrode remain inconsistent even after the compression process. Consequently, a problem arose where locally excessively dense and excessively loose regions coexisted due to particle aggregation. This density non-uniformity resulted not only in a degradation of the electrode's electrical properties but also in reduced mechanical strength and structural stability during repeated charging and discharging cycles.

[0009] Therefore, there is a continuous demand for a new electrode manufacturing technology that can simultaneously solve the structural limitations of conventional wet coating and dry powder processes, while controlling the thickness, density, and pore structure of the electrode plate more precisely and uniformly. Prior art literature

[0010] Korean Patent Publication No. 10-2024-0178183 (Published Dec. 30, 2024) The problem to be solved

[0011] The present invention was created to solve the above-mentioned problems and aims to enable uniform control of porosity and density distribution within the electrode while applying a solvent-free dry process.

[0012] In addition, the present invention has another objective of fundamentally resolving the problems of static electricity, scattering, and uneven distribution caused by directly handling electrode materials in powder form, and minimizing variations in thickness and adhesion of the electrode plate through a process of simultaneous compression on both sides of the current collector.

[0013] In addition, another objective of the present invention is to provide an electrode manufacturing technology suitable for designing high-output and high-performance lithium primary batteries by realizing an electrode that is structurally stable while having high porosity.

[0014] However, the technical problems that this embodiment aims to solve are not limited to the technical problems described above, and other technical problems may exist. means of solving the problem

[0015] A method for manufacturing an anode electrode plate using a dry annular carbon molded body according to one embodiment of the present invention comprises: a step of preparing a dry annular carbon molded body formed into an annular structure; a step of preparing a current collector having a porous structure; a step of placing the dry annular carbon molded body on one side and the other side of the current collector, respectively; and a step of applying pressure in a mutually opposing direction to both sides of the current collector to press-bond the dry annular carbon molded body so that it penetrates the pores of the current collector and comes into contact with one another.

[0016] In addition, the above dry annular carbon molded body is characterized by being molded into an annular structure including carbon black, acetylene black, Ketchen black, graphite, or a mixture thereof and a binder.

[0017] In addition, the above dry annular carbon molded body is characterized by being formed with a diameter in the range of 1.0 mm to 5.0 mm.

[0018] In addition, the dry annular carbon molded body is characterized by maintaining an independent molded body shape without being separated into a powder state prior to the compression bonding step.

[0019] In addition, the current collector is characterized by being composed of any one of a metal perforated plate, a metal mesh, or a metal foam.

[0020] In addition, the current collector is characterized by being formed with a thickness in the range of 0.1 mm to 0.3 mm.

[0021] In addition, the current collector is characterized by having a porous structure with a porosity of 20% to 60%.

[0022] In addition, the current collector is characterized by comprising nickel or stainless steel (SUS) that is chemically stable to thionyl chloride (SOCl2).

[0023] In addition, the step of the compression bonding is characterized by being performed using a double-sided press method in which pressure is applied simultaneously from both sides with respect to the normal direction of the current collector.

[0024] In addition, an anode electrode plate using a dry annular carbon molded body according to one embodiment of the present invention comprises: a dry annular carbon molded body formed into an annular structure; and a current collector having a porous structure, wherein the dry annular carbon molded body is disposed on one side and the other side, respectively, and is characterized by being manufactured by press-bonding the dry annular carbon molded body so that it penetrates the pores of the current collector and comes into mutual contact by applying pressure in a mutually opposing direction to both sides of the current collector using a press.

[0025] In addition, the anode electrode plate is characterized by having a thickness of 0.4 mm to 1.0 mm, a porosity of 40% or more, and a porosity deviation of 10% or less. Effects of the invention

[0026] As described above, according to the method for manufacturing an anode electrode plate using a dry annular carbon molded body of the present invention, a dry annular carbon molded body formed into an annular structure is placed on both sides of a current collector and then compressed simultaneously on both sides to form an anode electrode plate with a uniform thickness and density distribution throughout, thereby preventing pore non-uniformity and adhesion variation caused by drying shrinkage which were problems in the wet process, and has the effect of resolving problems such as electrostatic generation, powder scattering, and local density variation that occur in the dry powder process.

[0027] In addition, the present invention enables the realization of an electrode with a smooth lithium ion diffusion path and low electrode reaction resistance by stably maintaining the internal pore structure of the electrode while securing high porosity, thereby improving charge-discharge characteristics and enhancing the mechanical stability and repeated charge-discharge life of the electrode.

[0028] In addition, the present invention has a highly advantageous effect for the mass production of high-performance lithium primary batteries by improving manufacturing efficiency and productivity through process simplification and equipment reduction.

[0029] However, the effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the attached drawings. Brief explanation of the drawing

[0030] FIG. 1 is a diagram illustrating the manufacturing process of an anode electrode plate using a dry annular carbon molded body according to one embodiment of the present invention. FIG. 2 is a diagram showing an example of an anode electrode plate manufactured according to the manufacturing method applied to the present invention. FIG. 3 is a flowchart showing in detail the operation process of a method for manufacturing an anode electrode plate using a dry annular carbon molded body according to one embodiment of the present invention. Specific details for implementing the invention

[0031] Specific embodiments of the present invention will be described in detail below with reference to the drawings. However, the concept of the present invention is not limited to the presented embodiments. Those skilled in the art who understand the concept of the present invention may easily propose other inventions that are inferior or other embodiments included within the scope of the concept of the present invention by adding, changing, or deleting other components within the same scope of the concept, and such are also to be considered to be included within the scope of the concept of the present invention.

[0032] Additionally, components with the same function within the scope of the same concept appearing in the drawings of each embodiment are described using the same reference numeral.

[0033] FIG. 1 is a drawing for explaining the manufacturing process of an anode electrode plate using a dry annular carbon molded body according to one embodiment of the present invention, and FIG. 2 is a drawing showing an example of an anode electrode plate manufactured according to the manufacturing method applied to the present invention.

[0034] As shown in FIGS. 1 and 2, the positive electrode plate (100) of the present invention is manufactured by placing a dry annular carbon molded body (110), which is formed into an annular structure, on each side of a porous current collector (120), and then simultaneously pressing both sides of the current collector (120) with a press (200).

[0035] The above dry annular carbon molded body (110) is formed by molding a carbon-based material that functions as an electrode active material into an annular structure, and is configured to form an electrode by placing it on each side of the current collector (120) and using a press (200) to form a compression bonding process.

[0036] The above dry annular carbon molded body (110) comprises carbon black, acetylene black, Ketchen black, graphite, or a mixture thereof, and the carbon-based material mixed in this way is mixed with a binder and then molded into an annular structure.

[0037] At this time, the above dry annular carbon molded body (110) is preferably formed with a diameter in the range of 1.0 mm to 5.0 mm, and must be able to maintain an independent dry structure that does not collapse into a powder state until compression bonding using a press (200) is performed.

[0038] The above-described dry annular carbon molded body (110) formed in this way suppresses scattering of individual particles or generation of static electricity, and enables mutual contact through the gaps of the electric current collector (120) when compressed using a press (200), thereby enabling uniformity of the internal structure of the electrode.

[0039] Here, the reason the above dry annular carbon molded body (110) is set to a diameter range of 1.0 mm to 5.0 mm is for the bonding stability with the current collector (120) having a porous structure, the uniformity of the internal pore structure of the electrode, and handling during the compression process.

[0040] For example, if the diameter of the dry annular carbon molded body (110) is less than 1.0 mm, the molded body becomes closer to a fine particle aggregate, increasing the likelihood of separation or scattering before the compression bonding process, and it may be difficult to form a stable mutual contact structure by penetrating the voids of the electric current collector (120).

[0041] In addition, if the diameter of the above dry annular carbon molded body (110) exceeds 5.0 mm, the size of the molded body becomes excessively large compared to the pore distribution of the above electric current collector (120), resulting in an uneven distribution within the plane, and localized density concentration or pore collapse may occur during the compression bonding process using a press (200).

[0042] Accordingly, in the present invention, the diameter of the dry annular carbon molded body (110) is set to a range of 1.0 mm to 5.0 mm so that it can effectively penetrate the voids of the electric current collector (120) and simultaneously secure a uniform pore structure and stable mechanical bond inside the electrode.

[0043] The above current collector (120) is a metal current collector having a porous structure for collecting electrons generated from an electrode into an external circuit, and is configured such that the above dry annular carbon molded body (110) is placed on one side and the other side (i.e., the upper and lower sides in the drawing) respectively and is supported by a press (200) by compression bonding.

[0044] The current collector (120) may be made of any one of a metal perforated plate, a metal mesh, or a metal foam, and it is preferable that the thickness be formed in the range of 0.1 mm to 0.3 mm.

[0045] In addition, it is preferable that the current collector (120) be configured to have a porous structure with a porosity of 20% to 60%.

[0046] In addition, the current collector (120) can be formed using nickel or stainless steel (SUS) that is chemically stable to thionyl chloride (SOCl2), thereby ensuring chemical stability and structural durability even in a thionyl chloride-based battery environment.

[0047] In particular, since the dry annular carbon molded body (110) is disposed on each of the one side and the other side of the current collector (120), the in-plane dispersion and positional stability of the dry annular carbon molded body (110) can be secured by its own porous structure even without a separate additional structure.

[0048] Here, the reason for forming the thickness of the current collector (120) in the range of 0.1 mm to 0.3 mm and forming it to have a porous structure with a porosity in the range of 20% to 60% is to ensure balanced compression bonding stability with the dry annular carbon molded body (110) and electrical and mechanical properties of the entire electrode.

[0049] For example, if the thickness of the current collector (120) is less than 0.1 mm, the possibility of the current collector (120) being deformed or damaged during the compression process of the press (200) increases, and the structural stability of the electrode may be reduced as a result.

[0050] In addition, if the thickness of the current collector (120) exceeds 0.3 mm, the rigidity increases excessively, making it difficult for the dry annular carbon molded body (110) to penetrate the gaps and come into contact with each other, and the total thickness of the electrode increases, which may lower the energy density.

[0051] In addition, if the porosity of the current collector (120) is less than 20%, the penetration of the pores and mechanical interlocking of the dry annular carbon molded body (110) may be limited, and the bonding strength may be reduced. If the porosity exceeds 60%, the mechanical strength may be reduced, and structural stability may be reduced due to repeated charging and discharging or external forces.

[0052] Accordingly, in the present invention, the thickness of the current collector (120) is set to a range of 0.1 mm to 0.3 mm, and at the same time, the porous structure is set to a range of 20% to 60%, thereby ensuring stable compression bonding with the dry annular carbon molded body (110) and excellent current collection performance simultaneously.

[0053] The above press (200) is a pressurizing device for simultaneously pressing the dry annular carbon molded body (110) placed on both sides of the current collector (120), and is configured as a double-sided press that applies pressure in directions opposite to each other with respect to the normal direction of the current collector (120).

[0054] When pressure is applied by the above press (200), a portion of the dry annular carbon molded body (110) penetrates into the void of the current collector (120), and accordingly, the dry annular carbon molded bodies (110) placed on one side and the other side of the current collector (120) penetrate the void and are compressed and bonded in a state of contact with each other.

[0055] This press compression process can stably secure mechanical bonding strength between the dry annular carbon molded body (110) and the current collector (120) without the need for a separate solvent or wet coating process.

[0056] The positive electrode plate (100) applied in the present invention refers to a finished electrode plate having a structure in which the dry annular carbon molded bodies (110) arranged on both sides are fixed in contact with each other by penetrating the gap of the current collector (120) through a compression process by the press (200) as shown in FIG. 2. That is, it is manufactured using a double-sided press method in which pressure is applied simultaneously from both sides through the press (200) based on the normal direction of the current collector (120).

[0057] The anode electrode plate (100) manufactured in this way is preferably formed with an overall thickness in the range of 0.4 mm to 1.0 mm for high rate characteristics, electrode reaction uniformity, structural stability, etc., and maintains a porosity of 40% or more and a porosity deviation of 10% or less inside the electrode.

[0058] For example, if the thickness of the positive electrode plate (100) is less than 0.4 mm, there may be a limit to securing energy density due to insufficient loading of active material, and if the thickness exceeds 1.0 mm, the ion diffusion path inside the electrode becomes excessively long, which may increase reaction resistance during high-rate charging and discharging.

[0059] In addition, if the average porosity inside the electrode is less than 40%, electrolyte penetration and ion movement may be restricted, and the electrode reaction may become uneven. Conversely, if the porosity is excessively high, the mechanical strength of the electrode may be reduced. Therefore, the anode electrode plate (100) applied in the present invention is designed to maintain a uniform pore distribution throughout the electrode by setting the average porosity to 40% or more and controlling the pore deviation to 10% or less.

[0060] As such, since the anode electrode plate (100) is manufactured based on a dry process, problems such as drying shrinkage, non-uniformity of pore structure, and deviation in adhesion that occur in conventional wet slurry coating processes can be prevented, and problems such as powder scattering and deviation in density that occur in dry powder processes can also be resolved.

[0061] Meanwhile, when manufacturing the positive electrode plate of the present invention, the dry annular carbon molded body (110) is described as being formed with a single diameter as an example, but a method of mixing multiple dry annular carbon molded bodies having different diameters and arranging them on both sides of the current collector may also be applied.

[0062] In other words, a relatively large-diameter dry annular carbon molded body forms the mechanical support structure of the electrode, while a small-diameter dry annular carbon molded body fills the gaps, thereby enabling more uniform control of the pore structure inside the electrode.

[0063] In addition, the above dry annular carbon molded body (110) may form fine irregularities on its surface or adjust the binder composition during the molding process to increase the mechanical bonding force with the voids of the current collector in the press-bonding process using a press, thereby improving the structural stability and charge / discharge durability of the electrode.

[0064] Additionally, temporary guide sheets or alignment frames may be installed on both sides of the current collector (120) to guide the placement of the dry annular carbon molded body (110), and may be configured to be removed before performing the press process or to naturally detach during the compression process.

[0065] In addition, when performing double-sided compression using the above press (200), in addition to performing it under a single pressure condition, it is also possible to use a stepwise compression method in which low-pressure compression is performed first, and then high-pressure compression is performed second. This is to further improve the uniformity of the internal density distribution of the electrode by performing the main compression after stably performing the initial position alignment of the above dry annular carbon molded body (110).

[0066] Next, an embodiment of a method for manufacturing an anode electrode plate using a dry annular carbon molded body according to the present invention configured as described above will be explained in detail with reference to FIG. 3. At this time, the order of each step according to the method of the present invention may be changed depending on the usage environment or a person skilled in the art.

[0067] FIG. 3 is a flowchart showing in detail the operation process of a method for manufacturing an anode electrode plate using a dry annular carbon molded body according to one embodiment of the present invention.

[0068] As illustrated in FIG. 3, the method for manufacturing an anode electrode plate applied in the present invention can be carried out in the following order.

[0069] First, a dry annular carbon molded body (110) formed into an annular structure is prepared (S100). That is, a dry annular carbon molded body (110) that does not collapse into a powder state is molded before the compression process by a press (200) with a diameter of 1.0 mm to 5.0 mm.

[0070] Next, a porous current collector (120) is prepared (S200). That is, a current collector (120) is made of any one of a metal perforated plate, a metal mesh, or a metal foam having a porous structure with a thickness of 0.1 mm to 0.3 mm and a porosity of 20% to 60%.

[0071] When the dry annular carbon molded body (110) and the current collector (120) are prepared through the above steps S100 and S200, the dry annular carbon molded body (110) is placed on each side of the current collector (120) (S300).

[0072] Then, a press (200) is driven in a direction opposite to each other on both sides of the current collector (110) (S400), and the dry annular carbon molded body (110) is compressed and joined so that it penetrates the gap of the current collector (120) and comes into contact with each other, thereby completing the positive electrode plate (100) (S500).

[0073] Thus, the present invention forms an anode electrode plate with a uniform thickness and density distribution across the entire electrode plate by placing a dry annular carbon molded body formed into an annular structure on both sides of a current collector and compressing it simultaneously on both sides. As a result, non-uniformity of pores and deviation in adhesion caused by drying shrinkage, which were problems in the wet process, do not occur, and problems such as static electricity generation, powder scattering, and local density deviation appearing in the dry powder process can be resolved.

[0074] In order to more clearly express the technical concept of the present invention, the attached drawings briefly depict or omit configurations that are unrelated to or have little relevance to the technical concept of the present invention.

[0075] Although the structure and features of the present invention have been described above based on embodiments according to the present invention, the present invention is not limited thereto, and it is obvious to those skilled in the art that various changes or modifications can be made within the spirit and scope of the present invention; therefore, it is noted that such changes or modifications fall within the scope of the appended claims. Explanation of the symbols

[0076] 100 : Positive electrode plate 110: Dry annular carbon molded body 120 : Current collector 200 : Press

Claims

Claim 1 A method for manufacturing an anode electrode plate using a dry annular carbon molded body, comprising the steps of: preparing a dry annular carbon molded body formed into an annular structure; preparing a current collector having a porous structure; and mixing and arranging the dry annular carbon molded bodies having different diameters on one side and the other side of the current collector. A method for manufacturing an anode electrode plate, comprising the step of applying pressure in mutually opposing directions to both sides of the current collector to press and bond the dry annular carbon molded body so that it penetrates the voids of the current collector and comes into mutual contact; wherein the dry annular carbon molded body is formed into an annular structure with a diameter ranging from 1.0 mm to 5.0 mm by including carbon black, acetylene black, Ketchen black, graphite, or a mixture thereof and a binder; wherein the step of pressing and bonding is performed using a double-sided press method in which pressure is applied simultaneously from both sides of the current collector, and wherein the relative position of the dry annular carbon molded body is stabilized through a first press, and then the density distribution inside the electrode is homogenized through a second press; and wherein the anode electrode plate manufactured through the pressing and bonding has a thickness of 0.4 mm to 1.0 mm, a porosity of 40% or more, and a porosity deviation of 10% or less within a range in which the mechanical strength of the electrode is maintained. Claim 2 delete Claim 3 delete Claim 4 A method for manufacturing an anode electrode plate according to claim 1, wherein the dry annular carbon molded body maintains an independent molded body shape without being separated into a powder state prior to the compression bonding step. Claim 5 A method for manufacturing an anode electrode plate according to claim 1, wherein the current collector is composed of any one of a metal perforated plate, a metal mesh, or a metal foam. Claim 6 A method for manufacturing an anode electrode plate according to claim 1, wherein the current collector is formed with a thickness in the range of 0.1 mm to 0.3 mm. Claim 7 A method for manufacturing an anode electrode plate according to claim 6, wherein the current collector has a porous structure with a porosity of 20% to 60%. Claim 8 A method for manufacturing an anode electrode plate according to claim 1, wherein the current collector comprises nickel or stainless steel (SUS) that is chemically stable to thionyl chloride (SOCl2). Claim 9 delete Claim 10 A positive electrode plate manufactured by the manufacturing method described in claim 1. Claim 11 delete

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