Secondary battery electrode manufacturing device and manufacturing method
The apparatus and method for laminating electrode sheets with controlled rolling conditions address the challenge of achieving optimal thickness, density, and electrolyte permeability in secondary battery electrodes, resulting in a high-loading electrode with improved performance and efficiency.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- LG ELECTRONICS INC
- Filing Date
- 2025-08-29
- Publication Date
- 2026-06-25
Smart Images
Figure KR2025013256_25062026_PF_FP_ABST
Abstract
Description
Secondary battery electrode manufacturing apparatus and manufacturing method
[0001] The present invention relates to an apparatus and method for manufacturing a secondary battery electrode, and more specifically, to a technology for realizing a high-loading electrode by laminating a plurality of electrode sheets manufactured by powder rolling in a continuous process.
[0002] Rechargeable batteries consist of a positive electrode, a negative electrode, an electrolyte, and a separator, and are devices that store and release electrical energy through repeated charging and discharging. In these rechargeable batteries, the electrodes, which contain the active material, are key components that determine energy storage capacity and output characteristics. Therefore, electrode manufacturing technology has established itself as an important research field directly linked to the improvement of rechargeable battery performance.
[0003] Electrode manufacturing methods are broadly classified into wet and dry processes. The wet process involves preparing a slurry by mixing an active material, a conductive material, and a binder with a solvent, applying it onto a current collector, and then drying and rolling to form an electrode. While this method has the advantage of being relatively stable, it is characterized by the use of solvents and the requirement of a drying step. On the other hand, the dry process involves manufacturing a freestanding sheet by directly rolling active material powder and laminating it onto a current collector; it is attracting attention for its ability to shorten the process and for its environmental benefits as it does not use solvents.
[0004] When evaluating electrode performance, electrode thickness and density are considered key factors. Increasing electrode thickness theoretically increases capacity by raising the active material content per unit area. However, as the electrode becomes thicker, the ion migration path lengthens and it becomes difficult for the electrolyte to penetrate inward, making it difficult for the reaction to occur uniformly across the entire electrode. On the other hand, while increasing electrode density improves inter-particle contact and mechanical stability, excessive density may restrict the inflow of electrolyte, potentially reducing reactivity during the charging and discharging process.
[0005] Therefore, electrode manufacturing technology must comprehensively consider various factors such as thickness, density, electrolyte permeability, and mechanical stability, and it is generally recognized that existing processes have certain limitations in simultaneously satisfying these factors.
[0006] The present invention aims to provide an electrode manufacturing technology capable of simultaneously securing thickness and density by laminating electrode sheets in a dry electrode manufacturing process.
[0007] In addition, the present invention aims to provide an electrode structure capable of considering both the electrolyte permeability and mechanical stability of the electrode through the control of multiple supply systems and interlayer properties.
[0008] The problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.
[0009] A secondary battery electrode manufacturing apparatus may be provided, comprising: a first supply unit in the shape of a hopper for supplying a first mixed powder; a first rolling unit including a pair of rolling rolls disposed below the first supply unit for rolling the first mixed powder to form a first electrode sheet; a second supply unit in the shape of a hopper for supplying a second mixed powder; a second rolling unit including a pair of rolling rolls disposed below the second supply unit for rolling the second mixed powder to form a second electrode sheet; and a stacking rolling unit including at least one pair of rolling rolls for stacking and rolling the first electrode sheet and the second electrode sheet.
[0010] The first electrode sheet and the second electrode sheet may have different materials or physical properties.
[0011] It may further include an individual rolling section comprising at least one pair of rolling rolls that additionally roll the first electrode sheet or the second electrode sheet before reaching the stacked rolling section.
[0012] The number of times the first electrode sheet is rolled and the number of times the second electrode sheet is rolled may be different from each other.
[0013] The rolling roll included in the first rolling section and the rolling roll included in the second rolling section may be set to different temperatures or speeds.
[0014] The second supply unit directly supplies the second mixed powder to the lamination rolling unit, and a pair of rolling rolls included in the lamination rolling unit can simultaneously perform the formation and lamination of the second electrode sheet.
[0015] Each of the above rolling rolls can have its temperature or speed controlled independently.
[0016] The first electrode sheet and the second electrode sheet can be supplied to the lamination rolling section and laminated immediately after being formed through rolling.
[0017] A method for manufacturing a secondary battery electrode can be provided, comprising the steps of: rolling a first mixed powder to form a first electrode sheet; rolling a second mixed powder to form a second electrode sheet; stacking the first electrode sheet and the second electrode sheet formed above; and rolling the stacked first electrode sheet and the second electrode sheet to form a single electrode sheet.
[0018] The first electrode sheet and the second electrode sheet may have different materials or physical properties.
[0019] The method may further include a step of additionally rolling the first electrode sheet or the second electrode sheet prior to the above lamination step.
[0020] The additional rolling step described above can be controlled according to the physical properties of the first electrode sheet or the second electrode sheet.
[0021] The number of times the first electrode sheet is rolled and the number of times the second electrode sheet is rolled may be different from each other.
[0022] According to one embodiment of the present invention, a single electrode with an eliminated interface can be formed by laminating electrode sheets.
[0023] In addition, productivity can be secured in the electrode manufacturing process by utilizing multiple supply systems.
[0024] In addition, electrolyte permeability and mechanical stability can be considered together by controlling the interlayer density or porosity.
[0025] In addition, by simultaneously securing the thickness and density of the electrode, the active material loading per unit area can be increased.
[0026] Further scopes of the applicability of the present invention will become apparent from the following detailed description. However, since various changes and modifications within the spirit and scope of the present invention are clearly understood by those skilled in the art, specific embodiments, such as the detailed description and preferred embodiments of the present invention, should be understood as being given merely as examples.
[0027] FIG. 1 is a schematic diagram showing a secondary battery electrode manufacturing apparatus according to one embodiment of the present invention.
[0028] FIG. 2 is a schematic diagram showing a stacking rolling section in a schematic diagram of a secondary battery electrode manufacturing apparatus according to one embodiment of the present invention.
[0029] FIG. 3 is a schematic diagram of a secondary battery electrode manufacturing apparatus according to another embodiment of the present invention.
[0030] FIG. 4 is a schematic diagram of a secondary battery electrode manufacturing apparatus according to another embodiment of the present invention.
[0031] FIG. 5 is a schematic diagram of a secondary battery electrode manufacturing apparatus according to another embodiment of the present invention.
[0032] FIG. 6 is a flowchart of a method for manufacturing a secondary battery electrode according to one embodiment of the present invention.
[0033] FIG. 7 is a graph illustrating the performance of a secondary battery electrode manufactured by a secondary battery electrode manufacturing method according to one embodiment of the present invention.
[0034] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are given the same reference number, and redundant descriptions thereof will be omitted.
[0035] The suffixes "module" and "part" for components used in the following description are assigned or used interchangeably solely for the sake of ease of drafting the specification, and do not inherently possess distinct meanings or roles. Furthermore, in describing the embodiments disclosed in this specification, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions could obscure the essence of the embodiments disclosed in this specification.
[0036] In addition, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that all modifications, equivalents, and substitutions included within the concept and technical scope of the present invention are included.
[0037] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.
[0038] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.
[0039] A singular expression includes a plural expression unless the context clearly indicates otherwise.
[0040] In this application, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.
[0041] FIG. 1 illustrates the configuration of a secondary battery electrode manufacturing apparatus (1) according to one embodiment of the present invention. The apparatus (1) may include a first sheet forming line, a second sheet forming line, and a stacking rolling section (30).
[0042] A first supply unit (11) and a first rolling unit (13) are arranged in the first sheet forming line, and a second supply unit (21) and a second rolling unit (23) are arranged in the second sheet forming line. After an electrode sheet is formed independently in each line, it can be continuously supplied to a stacking rolling unit (30) along a guide path.
[0043] In particular, in this embodiment, the first electrode sheet and the second electrode sheet can be continuously supplied to the stacking rolling unit automatically immediately after being formed independently, without any separate storage or waiting process. Through this immediate stacking rolling process, the formation and stacking of each sheet can be connected as a single flow. Accordingly, unnecessary delays in the entire manufacturing process can be minimized, and all steps from sheet formation to the completion of the final single electrode sheet can be synchronized and proceed efficiently. Therefore, the effect of significantly reducing manufacturing time compared to the conventional method can be achieved.
[0044] The first supply unit (11) is a hopper-shaped container that stores the first mixed powder (12) and can supply the powder to the first rolling unit (13) through a lower opening. The first mixed powder (12) may be a composition for producing a first electrode sheet comprising an active material, a conductive material, and a binder.
[0045] The first rolling section (13) includes a pair of first rolling rolls and can form a first electrode sheet (121) by controlling the gap between the rolls, surface conditions, and driving speed. At this time, if the rotation speeds of the two rolling rolls are set differently, compressive force and shear force act simultaneously between the powder particles. In this process, the powder particles interlock with each other and are bound together in a sheet form, and under heated and pressurized conditions, the polymer binder is fibrillized, further strengthening the bonding force between the particles. Therefore, the first electrode sheet (121) can be formed with a dense yet uniform structure.
[0046] The formed first electrode sheet (121) can be continuously transported to the stacking rolling section (30) by passing through an intermediate roller with the tension and driving direction stabilized.
[0047] The second supply unit (21) stores the second mixed powder (22) in a hopper shape and supplies it to the second rolling unit (23) through a lower opening. The second rolling unit (23) forms a second electrode sheet (221) by rolling the powder using a pair of rolling rolls. In this process, compressive and shear forces are applied in parallel to promote inter-particle bonding and induce binder fiberization, thereby obtaining a stable sheet structure. The formed second electrode sheet (221) is transported through a guide roller to join with the first electrode sheet (121).
[0048] The stacking rolling unit (30) includes a plurality of rolling rolls (301, 302) and sequentially rolls the first electrode sheet (121) and the second electrode sheet (221) in a stacked state. Each rolling roll can independently control the gap, rotation speed, and temperature, and by distributing the total reduction amount through stepwise rolling, the internal adhesion and surface flatness of the stacked sheets can be secured. Finally, the stacked body that passes through the stacking rolling unit (30) is integrated into a single electrode sheet (321) and discharged, which can be transferred to a subsequent stage through a winding device or a cutting process.
[0049] As a result of the experiment, it was possible to realize a single electrode sheet without boundaries by applying the lamination rolling process of the present invention. Through lamination rolling, the total thickness increased by approximately 86.7%, allowing for the final production of a high-loading laminated sheet with a thickness of 224 μm, while the porosity of the sheet was found to be similar to that of a single sheet.
[0050] When observing the cross-section of the fabricated sheet under a microscope, the boundaries between each layer are not distinguishable, confirming that it is practically integrated into a single electrode sheet.
[0051] When manufacturing such a thick film high-loading electrode, a problem may arise where the film density decreases if the reduction amount is reduced; however, if electrode films manufactured by powder rolling are laminated and then additional rolling is performed, a high-loading electrode can be realized without a decrease in film density.
[0052] Furthermore, there are limitations to increasing the manufacturing speed of the powder rolling process, which can lead to a decrease in overall productivity. By utilizing a method of laminating multiple powder-rolled films and performing additional rolling as in the present invention, the overall manufacturing speed can be increased without increasing the manufacturing speed of the powder rolling process.
[0053] Meanwhile, the conditions of the first sheet forming line and the second sheet forming line can be set independently. For example, the speed and temperature of each rolling section can be controlled separately to adjust each electrode sheet to meet the target thickness and physical properties. Synchronization control is performed so that the two sheets are supplied to the stacking rolling section (30) immediately after forming, so that continuous stacking is performed without waiting time between processes.
[0054] In addition, the first and second electrode sheets may be made of materials with different physical properties to maximize the ease of electrolyte penetration, and the porosity of each sheet may also be designed differently. For example, the first electrode sheet can be manufactured to have high mechanical strength and low porosity to ensure structural stability, while the second electrode sheet can be composed of a material with relatively high porosity and excellent electrolyte absorption characteristics to facilitate the diffusion and penetration of the electrolyte. Through such customized design, functional division of labor among electrode materials within a single electrode sheet can be realized, while simultaneously improving the performance and lifespan of the entire battery.
[0055] In addition, the sheet tension in the lamination path is precisely controlled by intermediate rollers and guide rollers, and the guide angle, contact angle, roller diameter, etc., can be adjusted to suit design conditions to suppress driving deviations. If necessary, the surface of the electrode sheet immediately before lamination can be brushed or air blown to prevent foreign matter from adhering. The single electrode sheet (321) formed in this way can secure a uniform thickness and excellent interlayer adhesion, and can be handled stably in subsequent processes.
[0056] FIG. 2 is a schematic diagram showing a stacked rolling section (301) in a schematic diagram of a secondary battery electrode manufacturing device according to one embodiment of the present invention.
[0057] Referring to FIG. 2, the first electrode sheet (121) and the second electrode sheet (221) are supplied to the stacking rolling unit (301) in an overlapping state. The stacking rolling unit (301) includes at least one pair of rolling rolls (301), and the two sheets are subjected to pressure as they pass between the rolls. In this process, the gap between the sheets is eliminated and the two sheets can be brought into close contact.
[0058] If the gap or pressure between rolls is properly controlled during the rolling process, the sheet can be processed to a uniform thickness and integrated in a direction where the interface disappears. The single electrode sheet (321) formed in this way is continuously supplied to subsequent processes and can be maintained in a state where the mechanical stability of the electrode is ensured.
[0059] The arrow in FIG. 2 indicates the transport direction of the electrode sheet, and the first electrode sheet (121) and the second electrode sheet (221) continuously pass through the stacking rolling section (301) to be converted into a single electrode sheet (321). The operation of such a stacking rolling section has structural features that can resolve inter-sheet interface problems while simultaneously controlling the electrode thickness and density.
[0060] FIG. 3 illustrates the configuration of a secondary battery electrode manufacturing apparatus (1) according to another embodiment of the present invention. A first supply unit (11) stores a first mixed powder (12) in a hopper shape and supplies it to a first rolling unit (13) through a lower opening. The first rolling unit (13) includes a pair of rolling rolls, and the first mixed powder (12) passing through these rolling rolls is formed into a first electrode sheet (121) by receiving compression and shear force. The formed first electrode sheet (121) is transported via a guide roller.
[0061] Meanwhile, the second supply unit (21) stores the second mixed powder (22) in a hopper shape and supplies it to the second rolling unit (23) through a lower opening. The second rolling unit (23) includes a pair of rolling rolls and rolls the second mixed powder (22) to form a second electrode sheet (221). In this way, the first sheet forming line and the second sheet forming line each independently manufacture the electrode sheet.
[0062] The first electrode sheet (121) may pass through an individual rolling section (40) before reaching the stacking rolling section (30). The individual rolling section (40) may include one or more pairs of rolling rolls to further control the thickness and density of the first electrode sheet (121), and, if necessary, the second electrode sheet (221) may also pass through a separate individual rolling section.
[0063] In particular, to increase the permeability of the electrolyte, it is important to differentiate the porosity according to the position or thickness of the electrode, and to this end, the number of rolling processes for each electrode sheet can be applied differently. For example, by applying a rolling process with different numbers to the first electrode sheet (121) and the second electrode sheet (221), the density and porosity of each layer can be precisely controlled.
[0064] This method induces an appropriate pore distribution in each layer, enabling the electrolyte to penetrate more smoothly. Furthermore, controlling the porosity by adjusting the number of rolling passes can effectively improve the problem of reduced adhesion between the current collector and the electrode sheet in subsequent processes.
[0065] In this way, the number of times each electrode sheet is rolled can be set differently.
[0066] After the first electrode sheet (121) and the second electrode sheet (221) are each formed, they are supplied to the stacking rolling section (30) along a joining path. The stacking rolling section (30) includes a plurality of rolling rolls, and the two sheets are subjected to pressure as they pass between the rolls while overlapping. During this process, the interface between the sheets is eliminated, and they can finally be integrated into a single electrode sheet (321).
[0067] With this configuration, a single electrode sheet can be formed by independently manufacturing multiple electrode sheets and then performing lamination rolling, and the interlayer porosity and density can be adjusted by varying the composition or physical properties of each sheet. Therefore, electrolyte permeability and mechanical stability can be secured simultaneously with the realization of a high-loading electrode.
[0068] FIG. 4 illustrates the configuration of a secondary battery electrode manufacturing apparatus (1) according to another embodiment of the present invention. In this embodiment, a first mixed powder (12) is formed into a first electrode sheet (121) in a first supply unit (11) and a first rolling unit (13), and a second mixed powder (22) is formed into a second electrode sheet (221) in a second supply unit (21) and a second rolling unit (23). Furthermore, a third supply unit (51) and a third rolling unit (53) are additionally provided to roll a third mixed powder (52) to form a third electrode sheet.
[0069] In addition, although this embodiment describes three supply lines as examples, this is merely one example, and the number of supply lines can be expanded in various ways as needed. Each supply unit can be operated independently, and the supplied sheets can also be designed to have different physical properties (density, porosity, conductivity, etc.). This flexible control method can be effectively applied to implement various electrode structures and characteristics.
[0070] The first electrode sheet (121), the second electrode sheet (221), and the third electrode sheet are each formed on independent lines, then move along guide rollers and join together in a stacking path. During this process, the first electrode sheet (121) can pass through an individual rolling section (40) to correct its thickness and density, and if necessary, the second electrode sheet (221) and the third electrode sheet can also be configured to pass through a separate individual rolling section.
[0071] For example, in this embodiment, the process can be designed so that the first electrode sheet and the second electrode sheet each undergo two rolling processes, while the third electrode sheet undergoes only one rolling process. Additionally, if necessary, the first electrode sheet and the second electrode sheet can be configured to pass through individual rolling sections while stacked; this allows for flexible adjustment of the number of rolling cycles for each electrode sheet to achieve desired porosity and physical properties. This method is effective in simultaneously improving the structural stability and electrolyte permeability of the entire electrode by differentiating characteristics such as density or porosity for each electrode sheet.
[0072] The stacking rolling section (30) includes a plurality of rolling rolls, allowing three electrode sheets to pass between the rolls while overlapping. At this time, the gap between each sheet is compressed and eliminated, and the interlayer interface disappears, finally forming a single electrode sheet (321). Each rolling roll can independently control the temperature, speed, and reduction amount, so that the interlayer adhesion and the flatness of the entire sheet can be secured by varying the rolling conditions at each stage.
[0073] As shown in the embodiment of FIG. 4, if three or more supply and rolling sections are provided, electrode sheets having various compositions or physical properties can be manufactured simultaneously and then laminated. For example, the first electrode sheet (121) can be formed to have a high density, the second electrode sheet (221) to have a relatively high porosity, and the third electrode sheet to have a specific conductivity. By laminating with differentiated characteristics of each layer in this way, it is possible to achieve a high-loading electrode structure while simultaneously satisfying electrolyte permeability and mechanical stability.
[0074] Accordingly, in the embodiment according to FIG. 4, three sheet forming lines are operated simultaneously, and by integrating them into a single electrode sheet (321) in the lamination rolling section (30), thickness increase and porosity control can be easily achieved.
[0075] FIG. 5 illustrates the configuration of a secondary battery electrode manufacturing apparatus (1) according to another embodiment of the present invention. A first supply unit (11) stores a first mixed powder (12) in a hopper shape and supplies it to a first rolling unit (13) through a lower opening. The first rolling unit (13) includes a pair of rolling rolls and forms a first electrode sheet (121) by rolling the first mixed powder (12).
[0076] The formed first electrode sheet (121) moves toward the stacking rolling section via a guide roller. In this embodiment, the second supply section (21) stores the second mixed powder (22) and directly supplies the powder between the rolling rolls at the upper position of the stacking rolling section. Therefore, when the first electrode sheet (121) reaches the stacking rolling section, the second mixed powder (22) is supplied together, so that the powder and the sheet can be rolled simultaneously.
[0077] The stacked rolling section (30) includes a plurality of rolling rolls (301, 302, 303), and as the first electrode sheet (121) and the second mixed powder (22) pass between these rolls, they are simultaneously subjected to compression and shear forces. As a result, the powder is directly bonded to the surface of the first electrode sheet (121), forming a new layer, and can finally be integrated into a single electrode sheet (321).
[0078] In this case, two rollers (301, 302) can simultaneously perform the roles of the second rolling section (23) and the lamination rolling section (30). That is, by adjusting the arrangement and operating conditions of the rollers, a pair of rollers can directly apply powder to the surface of the sheet and simultaneously perform compression and lamination in batches. This method simplifies the equipment configuration and enables the efficient use of rollers, thereby further increasing the continuity and productivity of the entire manufacturing process.
[0079] This configuration has the advantage of eliminating the step of independently manufacturing the second electrode sheet in advance and then laminating it, as in conventional methods. That is, since the second mixed powder (22) is directly fed into the lamination rolling section, the same lamination effect can be achieved while shortening the process steps. In addition, by individually controlling the temperature, reduction amount, and rotation speed of the rolls during the rolling process, the powder and the sheet can be adjusted to ensure sufficient adhesion.
[0080] FIG. 6 illustrates a flowchart of a method for manufacturing a secondary battery electrode according to one embodiment of the present invention.
[0081] First, a first mixed powder is rolled to form a first electrode sheet (S6100). The first mixed powder (12) includes an active material, a conductive material, and a binder, and is supplied downward from a hopper-shaped first supply unit (11). As the first mixed powder (12) passes between a pair of rolling rolls of the first rolling unit (13), it is simultaneously subjected to compressive and shear forces and formed into a sheet shape. During this process, the binder is fibrillized to strengthen the bonding force between particles, and a first electrode sheet (121) having a uniform thickness and a dense structure is formed.
[0082] Next, the second mixed powder is rolled to form a second electrode sheet (S6200). The second mixed powder (22) is supplied from the second supply unit (21) and formed into a second electrode sheet (221) by passing through the rolling roll of the second rolling unit (23). The second electrode sheet (221) may have the same composition as the first electrode sheet (121), or it may be manufactured to have mutually complementary characteristics by having different physical properties such as density, thickness, porosity, and conductivity.
[0083] The formation of the first electrode sheet and the second electrode sheet may proceed sequentially, but preferably, the two processes are carried out simultaneously so that each electrode sheet is transferred to the stacking stage immediately after being formed independently. This allows for a reduction in the overall process time and ensures continuous manufacturability.
[0084] Next, the first electrode sheet and the second electrode sheet are stacked together (S6300). The two electrode sheets are formed independently and then joined along a transport path and arranged in an overlapping state. During this process, if necessary, the thickness or density of the first electrode sheet or the second electrode sheet can be adjusted by undergoing an additional rolling process. The number of rolling cycles or conditions for each sheet can be set differently, thereby allowing for the control of the interlayer density distribution or the difference in porosity.
[0085] Next, the stacked first electrode sheet and second electrode sheet are rolled (S6400). The stacking rolling unit (30) includes a plurality of rolling rolls, and the stacked sheets are compressed step by step as they pass between the rolls. During this process, the gaps between the sheets are eliminated, the interlayer interfaces gradually disappear, and the entire structure is integrated into a single continuous electrode sheet. During the rolling process, the gap between the rolls, the rotation speed, and the temperature can be controlled individually, thereby ensuring interlayer adhesion, surface flatness, and the mechanical stability of the entire sheet.
[0086] Finally, a single electrode sheet is formed (S6500). The sheet, having undergone lamination rolling, is completed as a single electrode sheet (321) with no visible interface, having a uniform thickness and a stable structure. The completed electrode sheet is manufactured with controlled porosity while maintaining a high active material loading, thereby ensuring electrolyte permeability, and can be wound or cut in a subsequent process to be applied as a final electrode.
[0087] Figure 7 illustrates the results of comparing the charge-discharge characteristics of a laminated electrode sheet and a general rolled sheet according to one embodiment of the present invention. The charge-discharge test was performed under 0.2C conditions, and the charge-discharge capacity per unit area was evaluated according to the type of electrode applied to the battery.
[0088] As can be seen in the graph, compared to a single sheet electrode manufactured by a conventional rolling method, the stacked sheet electrode manufactured by the method of the present invention was found to have a charge / discharge capacity per unit area of approximately 63.7%. This means that the electrode sheet formed through the stacked rolling process was able to load more active material within the same area.
[0089] In particular, both sheets exhibit similar charge / discharge capacities per unit weight, indicating that the basic reactivity of the electrode is maintained; furthermore, in the laminated electrode sheet, the active material content per unit area is increased, thereby realizing the characteristics of a high-loading electrode. Therefore, it can be demonstrated that the laminated electrode sheet of the present invention can be advantageously applied to secondary batteries requiring high-capacity characteristics.
[0090] As described above, the present invention relates to an apparatus and method for independently rolling a first mixed powder and a second mixed powder to form electrode sheets, stacking them, and then further rolling to form a single electrode sheet. Through a combination of a plurality of feed sections, a rolling section, an individual rolling section, and a stacking rolling section, the physical properties of the electrode sheet can be controlled step by step, and the stacked electrode sheets can be integrated into a single electrode sheet with no interfaces. According to this configuration, the electrode sheet can be manufactured with a uniform thickness and a stable structure and can be applied as an electrode in a subsequent process.
[0091] It is obvious to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential features of the invention.
[0092] The foregoing detailed description should not be interpreted restrictively in all respects and should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention.
Claims
1. A hopper-shaped first supply unit for supplying the first mixed powder; A first rolling unit comprising a pair of rolling rolls located below the first supply unit, and rolling the supplied first mixed powder to form a first electrode sheet; A hopper-shaped second supply unit for supplying a second mixed powder; A second rolling unit comprising a pair of rolling rolls located below the second supply unit and rolling the supplied second mixed powder to form a second electrode sheet; and A lamination rolling unit comprising at least one pair of rolling rolls for laminating and rolling the first electrode sheet and the second electrode sheet. Secondary battery electrode manufacturing device.
2. In Paragraph 1, A secondary battery electrode manufacturing apparatus characterized in that the first electrode sheet and the second electrode sheet have different materials or physical properties.
3. In Paragraph 1, A secondary battery electrode manufacturing apparatus characterized by further including an individual rolling section comprising at least one pair of rolling rolls that further roll the first electrode sheet or the second electrode sheet before reaching the stacked rolling section.
4. In Paragraph 1, A secondary battery electrode manufacturing apparatus characterized in that the number of times the first electrode sheet is rolled and the number of times the second electrode sheet is rolled are different.
5. In Paragraph 1, A secondary battery electrode manufacturing apparatus characterized by the fact that the temperature or speed of the rolling roll included in the first rolling section and the rolling roll included in the second rolling section are set differently from each other.
6. In Paragraph 1, The second supply unit directly supplies the second mixed powder to the lamination rolling unit, and A secondary battery electrode manufacturing apparatus characterized in that a pair of rolling rolls included in the above-mentioned lamination rolling section simultaneously perform the formation and lamination of the second electrode sheet.
7. In Paragraph 1, A secondary battery electrode manufacturing apparatus characterized in that each of the above rolling rolls has its temperature or speed controlled independently.
8. In Paragraph 1, A secondary battery electrode manufacturing apparatus characterized in that the first electrode sheet and the second electrode sheet are formed through rolling and simultaneously supplied to the lamination rolling section to be laminated.
9. A step of forming a first electrode sheet by rolling the first mixed powder; A step of forming a second electrode sheet by rolling the second mixed powder; A step of stacking the first electrode sheet and the second electrode sheet formed above; and A method for manufacturing a secondary battery electrode comprising the step of rolling the stacked first electrode sheet and second electrode sheet to form a single electrode sheet.
10. In Paragraph 9, A method for manufacturing a secondary battery electrode characterized in that the first electrode sheet and the second electrode sheet have different materials or physical properties.
11. In Paragraph 9, A method for manufacturing a secondary battery electrode, characterized by further including a step of additionally rolling the first electrode sheet or the second electrode sheet prior to the stacking step.
12. In Paragraph 11, The additional rolling step mentioned above A method for manufacturing a secondary battery electrode characterized by being controlled according to the physical properties of the first electrode sheet or the second electrode sheet.
13. In Paragraph 9, A method for manufacturing a secondary battery electrode characterized in that the number of times the first electrode sheet is rolled and the number of times the second electrode sheet is rolled are different.