Electrode assembly manufacturing apparatus and electrode assembly manufacturing method

Abstract

An electrode assembly manufacturing apparatus according to an embodiment of the present invention comprises: a transfer unit for transferring a unit cell; at least one pre-measurement vision unit provided to measure a positive electrode alignment position and a negative electrode alignment position of the unit cell; an alignment vision unit provided to measure a positive electrode alignment position of the unit cells when unit cells are stacked; a control unit provided to calculate interval data between a positive electrode and a negative electrode by using positive electrode alignment position data and negative electrode alignment position data measured from the pre-measurement vision unit, and calculate negative electrode alignment position data by using the interval data and the positive electrode alignment position data measured from the alignment vision unit; and a stacking unit provided to stack the unit cells by using the calculated negative electrode alignment position data.

Description

Electrode assembly manufacturing apparatus and electrode assembly manufacturing method

[0001] The present invention relates to an apparatus for manufacturing an electrode assembly and a method for manufacturing an electrode assembly, and more specifically, to an apparatus for manufacturing an electrode assembly and a method for manufacturing an electrode assembly capable of manufacturing an electrode assembly with improved energy density by accurately stacking unit cells through a vision system and precise control.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0154795 filed on November 5, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The importance of the secondary battery industry is growing day by day alongside the rapid growth of electric vehicles and energy storage systems (ESS). Particularly in fields requiring high capacity and high output characteristics, large-capacity battery cell assemblies consisting of tens to hundreds of cells are being applied; as a result, manufacturing technology for electrode assemblies is emerging as a key factor determining the performance and quality of secondary batteries.

[0004] FIG. 1 is a plan view schematically showing the structure of a conventional unit cell. FIG. 2 is a side view schematically showing a stack of conventional unit cells.

[0005] Referring to FIGS. 1 and 2, in a general secondary battery manufacturing process, a stacking method is mainly used to manufacture an electrode assembly by stacking unit cells based on a positive electrode. Here, as shown in FIGS. 1 and 2, a unit cell (1) is formed by sequentially stacking a first separator (4), a negative electrode (3) equipped with a negative electrode tab (3a), a second separator (5), and a positive electrode (2) equipped with a positive electrode tab (2a). Conventionally, the alignment position of the positive electrode (2) located at the top of the unit cell (1) is measured, and the unit cells (1) are sequentially stacked based on the measured alignment position of the positive electrode (2) to manufacture an electrode assembly.

[0006] In the above unit cell (1), the positive electrode (2) has a smaller area than the negative electrode (3) and is positioned so that the positive electrode overlaps within the negative electrode. At this time, referring to FIG. 1, when the positive electrode (2) is positioned within the negative electrode (3), a predetermined gap (L) is formed between the edge of the positive electrode (2) and the edge of the negative electrode (3).

[0007] FIG. 3 is a side view schematically showing the configuration of a conventional electrode assembly manufacturing device (10).

[0008] Referring to FIG. 3, a conventional electrode assembly manufacturing device (10) includes a conveyor belt (30) for transporting a holding unit (80) that adsorbs a unit cell (1), an alignment vision unit (40) for measuring the anode alignment position of the unit cell (1), a stacking vision unit (50) for checking the stacking state of the stacked unit cells (1), lighting units (71, 72) provided to illuminate the unit cell (1), and a stacking table (60) on which the unit cell (1) is stacked.

[0009] Referring to FIG. 1, the unit cell (1) includes an anode (2), a cathode (3), and a first separator (5) located between them. Several unit cells (1) are sequentially stacked based on the anode alignment position to form an electrode assembly of a predetermined width (W1). However, this stacking method based on the anode alignment position has several limitations.

[0010] First, when forming an electrode assembly by stacking multiple unit cells based on the alignment position of an anode with a smaller area than the cathode, there is a limit to effectively reducing the overall width (W1) of the formed electrode assembly. This poses a constraint on increasing the energy density of the electrode assembly.

[0011] Second, the cathode-anode overhang inspection—which checks whether the anode protrudes outside the cathode rather than being positioned to overlap within it—is performed using a sampling method via a CT (computed tomography) imaging inspection machine, making it difficult to conduct a 100% inspection of the produced electrode assemblies. This raises the possibility of defective products entering subsequent processes, which can have a serious impact on product quality and safety.

[0012] Third, since the alignment vision unit (40) mainly checks only the alignment state of the anode and the stacking vision unit (50) also checks only the alignment state of the anode after stacking, it is not possible to determine the position where the cathode is aligned, making it difficult to determine in real time whether the anode has protruded beyond the cathode.

[0013] Due to these problems, there is an urgent need to develop new technologies that can improve the energy density of electrode assemblies and control quality more precisely.

[0014] The present invention aims to solve the problems that occur in the conventional electrode assembly manufacturing process.

[0015] Specifically, through one embodiment of the present invention, the purpose is to provide a method for manufacturing an electrode assembly and an apparatus capable of accurately measuring the alignment positions of the anode and cathode during unit cell stacking and performing precise stacking based thereon.

[0016] In addition, the present invention aims to provide a method for manufacturing an electrode assembly and an apparatus capable of efficiently calculating spacing data between the positive and negative electrodes of a unit cell through one embodiment of the present invention, and accurately calculating the alignment position of the negative electrode by utilizing this data.

[0017] In addition, the present invention aims to provide a method for manufacturing an electrode assembly and an apparatus capable of effectively detecting and preventing anode-cathode overhang problems that may occur during the lamination process through an embodiment of the present invention.

[0018] To achieve the aforementioned objective, according to one embodiment of the present invention, an electrode assembly manufacturing apparatus is provided by stacking unit cells. The electrode assembly manufacturing apparatus comprises a transfer unit for transferring unit cells, at least one pre-measurement vision unit provided for measuring the anode alignment position and the cathode alignment position of the unit cells, an alignment vision unit provided for measuring the anode alignment position of the unit cells when stacking the unit cells, a control unit provided for calculating a gap data between the anode and the cathode using the anode alignment position data and the cathode alignment position data measured from the pre-measurement vision unit, and calculating a cathode alignment position data using the gap data and the anode alignment position data measured from the alignment vision unit, and a stacking unit provided for stacking the unit cells using the calculated cathode alignment position data.

[0019] The above-mentioned pre-measurement vision unit may include a first vision unit that measures at least two coordinates on the cathode side at the bottom of the unit cell and a second vision unit that measures at least two coordinates on the sides of the cathode and anode, respectively, at the top of the unit cell.

[0020] The control unit may be configured to calculate first interval data by comparing the position of at least the negative side measured by the first vision unit with the position of the positive side measured by the second vision unit, calculate second interval data by comparing the position of the negative side measured by the second vision unit with the position of the positive side, and select one interval data by comparing the accuracy of the first interval data and the second interval data.

[0021] The above control unit may be configured to calculate cathode alignment position data using the anode alignment position data measured by the alignment vision unit and the selected interval data.

[0022] The above electrode assembly manufacturing device may further include a stacking vision unit configured to measure the anode alignment position of a stacked unit cell. In this case, the control unit may be configured to calculate the cathode alignment position data of the stacked unit cell using the anode alignment position data measured by the stacking vision unit and the spacing data, and to perform an anode-cathode overhang inspection by comparing the measured anode alignment position data and the calculated cathode alignment position data of each of the stacked unit cells.

[0023] The above control unit may be configured to transmit the interval data through a PMAC (Programmable Multi-Axis Controller).

[0024] The above-mentioned conveying unit may include a conveyor belt configured to transport the upper portion of the unit cell in an attached state by suctioning it through an adsorption unit. In this case, the adsorption unit may have an area smaller than the positive electrode of the unit cell.

[0025] The above electrode assembly manufacturing device may further include an alignment unit configured to align the center of the negative electrode of the unit cell with the center of the stacking table. The alignment unit is configured to move the stacking table in the X-axis, Y-axis, and horizontal rotational directions, and the unit cell may be configured to be movable only in the X-axis direction by the transfer unit.

[0026] The control unit may be configured to analyze the upper and lower images of the unit cell measured by the pre-measurement vision unit to determine the accuracy of the interval data, and to perform the selection of the interval data according to the result of the determination.

[0027] To achieve the aforementioned objective, according to another embodiment of the present invention, a method for manufacturing an electrode assembly by stacking unit cells is provided, comprising: a preliminary measurement step of measuring an anode alignment position and a cathode alignment position of the unit cells using at least one vision unit; a gap data calculation step in which a control unit calculates gap data between an anode and a cathode based on the measured data of the anode alignment position and the cathode alignment position; a re-measurement step in which an alignment vision unit measures the anode alignment position of the unit cells; a cathode alignment position data calculation step in which the control unit calculates cathode alignment position data using the calculated gap data and the anode alignment position data measured in the re-measurement step; and a stacking step in which a stacking unit stacks the unit cells using the calculated cathode alignment position data.

[0028] The above preliminary measurement step may include a step in which a first vision unit measures the coordinates of at least two points on the cathode side at the bottom of the unit cell, and a step in which a second vision unit measures the coordinates of at least two points on the sides of the cathode and anode, respectively, at the top of the unit cell.

[0029] The above interval data calculation step may include the step of the control unit calculating first interval data by comparing the position of at least the negative side measured by the first vision unit with the position of the positive side measured by the second vision unit, the step of the control unit calculating second interval data by comparing the position of the negative side measured by the second vision unit with the position of the positive side, and the step of the control unit selecting one interval data by comparing the accuracy of the first interval data and the second interval data.

[0030] The above re-measurement step may include a step in which an alignment vision unit measures the coordinates of at least two points on the anode side of the unit cell and a step in which position data of the anode side is calculated by connecting the coordinates of the at least two measured points. The step of calculating cathode alignment position data may include a step in which the control unit calculates cathode alignment position data using the anode side position data measured by the alignment vision unit and the selected interval data.

[0031] The above method for manufacturing an electrode assembly may further include the step of a stacked vision unit measuring the anode alignment position of a stacked unit cell and the step of the control unit performing an anode-cathode overhang inspection by comparing the measured anode alignment position data and the calculated cathode alignment position data of each of the stacked unit cells.

[0032] The above anode-cathode overhang inspection may be characterized by the control unit comparing the cathode alignment position data calculated using the anode alignment position data and the spacing data of each of the stacked plurality of unit cells with the anode alignment position data to check if there is a part where the anode protrudes more than the cathode.

[0033] The above control unit may be configured to transmit the interval data through a PMAC (Programmable Multi-Axis Controller).

[0034] The above method for manufacturing an electrode assembly may further include an alignment step of aligning the center of the negative electrode of the unit cell with the center of the stacking table. The alignment step includes a step of moving the stacking table in the X-axis, Y-axis, and horizontal rotational directions, and the unit cell may be moved only in the X-axis direction.

[0035] The above method for manufacturing an electrode assembly may further include a step in which the control unit analyzes the upper image and the lower image of the unit cell measured in the above preliminary measurement step to determine the accuracy of the interval data, and a step of performing selection of the interval data according to the result of the determination.

[0036] The electrode assembly manufacturing apparatus and manufacturing method according to one embodiment of the present invention have the following effects.

[0037] By using a pre-measurement vision unit and an alignment vision unit to precisely measure the alignment positions of the anode and cathode of a unit cell, and stacking the unit cells based on the cathode, the overall width of the electrode assembly can be reduced and the energy density improved.

[0038] In addition, by equipping the pre-measurement vision unit with a first vision unit and a second vision unit, interval data can be calculated via two paths, and by selecting and using the more accurate data among them, stacking accuracy can be further improved.

[0039] In addition, by measuring the anode alignment position of stacked unit cells using a stacked vision unit and calculating cathode alignment position data based on this, real-time anode-cathode overhang inspection can be performed. This enables significant improvement in product quality and a reduction in the defect rate.

[0040] In addition, the secondary battery manufactured through the electrode assembly manufacturing apparatus and electrode assembly manufacturing method of the present invention includes an electrode assembly composed of unit cells aligned with respect to the negative electrode, so the overall width of the electrode assembly is reduced, thereby providing a high-performance secondary battery with improved energy density.

[0041] Figure 1 is a schematic plan view showing the structure of a conventional unit cell.

[0042] FIG. 2 is a schematic side view showing a stack of conventional unit cells.

[0043] FIG. 3 is a schematic side view showing the configurations of a conventional electrode assembly manufacturing device.

[0044] FIG. 4 is a conceptual block diagram showing the configuration of an electrode assembly manufacturing apparatus according to one embodiment of the present invention.

[0045] FIG. 5 is a schematic diagram showing the configurations of an electrode assembly manufacturing apparatus according to one embodiment of the present invention.

[0046] FIG. 6 is a schematic plan view showing the appearance of a unit cell manufactured by an electrode assembly manufacturing device according to one embodiment of the present invention.

[0047] FIG. 7 is a schematic side view showing a stack of unit cells manufactured by an electrode assembly manufacturing device according to one embodiment of the present invention.

[0048] FIG. 8 is a flowchart of a method for manufacturing an electrode assembly according to one embodiment of the present invention.

[0049] FIG. 9 is a flowchart showing the processes of a method for manufacturing an electrode assembly according to one embodiment of the present invention.

[0050] FIG. 10 is a partial cross-sectional view showing the appearance of an electrode assembly according to one embodiment of the present invention.

[0051] FIG. 11 is a plan view showing a secondary battery according to one embodiment of the present invention.

[0052] Hereinafter, an electrode assembly manufacturing apparatus (100) and an electrode assembly manufacturing method (200) according to one embodiment of the present invention will be described in detail with reference to the attached drawings.

[0053] Additionally, identical or corresponding components are assigned the same or similar reference numbers regardless of drawing symbols, and redundant descriptions thereof are omitted; furthermore, for the convenience of explanation, the size and shape of each illustrated component may be exaggerated or reduced.

[0054] FIG. 4 is a block diagram conceptually showing the configuration of an electrode assembly manufacturing device (100) according to one embodiment of the present invention. FIG. 5 is a schematic diagram schematically showing the configurations of an electrode assembly manufacturing device (100) according to one embodiment of the present invention.

[0055] Referring to FIGS. 4 and 5, an electrode assembly manufacturing device (100) according to one embodiment of the present invention includes a transfer unit (140), at least one pre-measurement vision unit (110), an alignment vision unit (120), a control unit (150), and a stacking unit (160).

[0056] A conveying unit (140) is provided to convey a unit cell (1). The conveying unit (140) may include an adsorption unit (142) and a conveyor belt (144). The adsorption unit (142) can adsorb and hold the unit cell (1). The conveyor belt (144) can continuously transport the adsorption unit (142) that has adsorbed the unit cell (1) in the conveying direction. Additionally, the conveyor belt (144) is provided to convey the unit cell (1) to a stacking unit (160). For example, as shown in FIG. 5, the conveyor belt (144) may be provided to allow the unit cell (1) to be transported in both directions of the X-axis.

[0057] The conveyor belt (144) can transport the upper part of the unit cell (1) by suctioning it through the suction part (142) and attaching it. At this time, the suction part (142) is designed to have an area smaller than that of the anode (2) so as not to interfere with the imaging of the second vision unit (112) for upper measurement of the unit cell (1) and the first vision unit (111) for lower measurement.

[0058] FIG. 6 is a schematic plan view showing the appearance of a unit cell manufactured by an electrode assembly manufacturing device according to one embodiment of the present invention, and FIG. 7 is a schematic side view showing a stack of unit cells manufactured by an electrode assembly manufacturing device according to one embodiment of the present invention.

[0059] A pre-measurement vision unit (110) is provided to measure the alignment position of the positive electrode (2) and the alignment position of the negative electrode (3) of the unit cell (1). Here, the positive electrode alignment position refers to stacking position information of the positive electrode (2) placed on the first separator (4) or the negative electrode (3). For example, the positive electrode alignment position may refer to the position information of the side of the positive electrode (2) and the position information of the central part of the positive electrode (2). Here, the negative electrode alignment position refers to stacking position information of the negative electrode (3) placed under the second separator (5) or the positive electrode (2). For example, the negative electrode alignment position may refer to the position information of the side of the negative electrode (3) and the position information of the central part of the negative electrode (3).

[0060] In this document, referring to FIG. 6, the sides of the positive electrode (2) and the sides of the negative electrode (3) may refer to the edges of the positive electrode (2) and the negative electrode (3), respectively. Referring to FIG. 6, when the pre-measurement vision unit (110) observes the unit cell (1) in a photographing direction, the positive electrode (2) and the negative electrode (3) may have a roughly rectangular shape and may each have four sides. At this time, the spacing between the sides of the positive electrode (2) and the negative electrode (3) may refer to the spacing (A1, A2, A3, A4) between two adjacent sides along the horizontal direction (the full width direction of the unit cell, x-axis direction) or the vertical direction (the front direction of the unit cell, y-axis direction).

[0061] In this document, the cathode (3), anode (2), and separator (4) can be distinguished based on the brightness value (Grey Value, GV) in the image taken from the vision units (110, 120).

[0062] The pre-measurement vision unit (110) may include a first vision unit (111) and a second vision unit (112). The first vision unit (111) may measure the coordinates of at least two points (P3, P4) on the sides of the cathode (3) at the bottom of the unit cell (1). For example, if the cathode (3) is rectangular, the first vision unit (111) may measure the coordinates of two points (P3, P4) on each of the four sides and transmit them to the control unit (150). For example, the control unit (150) may interpret the two points measured on the sides of the cathode (3) by the first vision unit (111) as one side of the cathode (3) by connecting them with a straight line. Likewise, the control unit (150) may interpret the remaining three sides of the cathode (3) in this manner.

[0063] Additionally, the second vision unit (112) can measure the coordinates of at least two points (P1, P2) on each side formed on the positive electrode (2) at the top of the unit cell (1) and the coordinates of at least two points (P3, P4) on each side formed on the negative electrode (3). For example, the control unit (150) can interpret the two points (P1, P2 or P3, P4) measured on each side of the positive electrode (2) and the negative electrode (3) by the second vision unit (112) as the sides of the positive electrode (2) and the negative electrode (3) by connecting them with a straight line. For example, if the positive electrode (2) and the negative electrode (3) are rectangular in shape, the second vision unit (111) can measure the coordinates of two points (P1, P2 or P3, P4) on each of the four sides of the positive electrode (2) and the negative electrode (3) and transmit them to the control unit (150). In addition, the control unit (150) can interpret the four sides of each of the positive electrode (2) and the negative electrode (3) in the manner described above.

[0064] The alignment vision unit (120) is configured to measure the alignment position of the anode (2) of the unit cell (1) when the unit cell (1) is stacked. For example, the alignment vision unit (120) can measure the coordinates of at least two points (P1, P2) on each side of the anode (2) of the unit cell (1). For example, the control unit (150) can connect the two points measured on the side of the anode (2) with a straight line to interpret them as one side of the anode (2). Additionally, the control unit (150) can utilize the data measured by the alignment vision unit (120) to interpret the four sides of the anode (2) in the manner described above.

[0065] The electrode assembly manufacturing device (100) of the present invention may include a plurality of lighting units (171, 172, 173, 174) to assist in accurate measurement of vision units (111, 112, 120, 130). Specifically, the first lighting unit (171) is located near the first vision unit (111) to illuminate the lower part of the unit cell (1), and the second lighting unit (172) is placed near the second vision unit (112) to illuminate the upper part of the unit cell (1). Additionally, the third lighting unit (173) is installed around the alignment vision unit (120) to illuminate the unit cell (1) immediately before stacking, and the fourth lighting unit (174) is located near the stacking vision unit (130) to illuminate the stacked unit cells (1).

[0066] Accordingly, the present invention provides lighting units that improve the clarity and contrast of the image by providing lighting conditions optimized for the measurement target of each vision unit, thereby clearly distinguishing the boundary between the anode (2) and the cathode (3) and obtaining accurate position data.

[0067] Additionally, the control unit (150) can calculate gap data, which is the distance between the sides of the anode (2) and the cathode (3), using the anode alignment position data and the cathode alignment position data measured from the pre-measurement vision unit (110). Here, the distances (A1, A2, A3, A4) between the sides of the anode (2) and the sides of the cathode (3) are called the anode-cathode gap. For example, as shown in FIG. 6, the distances (A1, A2, A3, A4) between the sides of the anode in the X and Y axis directions and the sides of the cathode in the X and Y axis directions can be calculated as gap data. It is configured to calculate cathode alignment position data using the gap data and the anode alignment position data measured from the alignment vision unit (120).

[0068] The control unit (150) transmits the anode-cathode gap data measured by the pre-measurement vision unit (110) to the alignment vision unit (120). The alignment vision unit (120) calculates the side position value of the cathode (3) and the center value of the cathode (3) using the anode (2) alignment position value and the anode-cathode gap data.

[0069] The stacking table (162) is configured to allow movement in the X-axis and Y-axis directions (horizontal direction) and horizontal rotational movement to align the center of the stacking table (162) with the center of the cathode (3). The unit cell (1) is configured to be movable only in one direction (X-axis direction) by the conveyor belt (144).

[0070] The center of the stacking table (162) is measured through the alignment vision unit (120), and at this time, the control unit (150) can calculate the center value of the stacking table (162) from the measured image using the SRM (Stage Reference Mark) mark each time. Through this, accurate alignment of the unit cell (1) is possible.

[0071] Meanwhile, the control unit (150) can distinguish the cathode (3), anode (2), and separator (4) based on the brightness value (Grey Value, GV) in the images captured from the vision units (110, 120, 130). The control unit (150) can distinguish the components using, for example, the following GV ranges.

[0072] - Anode: 0 GV to 40 GV

[0073] - Cathode: 40 GV to 100 GV

[0074] - Separator: 100 GV to 180 GV

[0075] The control unit (150) may include at least one computer (not shown) and a communication unit (not shown) capable of communicating with vision units (110, 120, 130). The communication unit may transmit and receive data using wired or wireless communication methods. Through this, the control unit (150) can collect measurement data from the vision units in real time, exchange data with the computer, and transmit control commands.

[0076] The control unit (150) may also include a processor that processes and analyzes collected data, and a memory that stores data and programs. The processor may be implemented as a high-performance central processing unit (CPU) or a dedicated signal processing unit (DSP) and may perform complex calculations and algorithm processing. The memory may be implemented in various forms such as RAM, ROM, and flash memory and stores measurement data, calculation results, control algorithms, etc.

[0077] Additionally, the control unit (150) may include a user interface. This may be implemented as a touchscreen, keypad, display, etc., and allows an operator to monitor the manufacturing process and intervene manually if necessary.

[0078] Specifically, the control unit (150) can calculate first interval data by comparing the position of at least the negative side (3) measured by the first vision unit (111) with the position of the positive side (2) measured by the second vision unit (112). Additionally, the control unit (150) can calculate second interval data by comparing the position of the negative side (3) measured by the second vision unit (112) with the position of the positive side (2). The control unit (150) can select one interval data by comparing the accuracy of the first interval data and the second interval data. At this time, the control unit (150) can evaluate the accuracy of the interval data using an algorithm that evaluates the accuracy of the interval data.

[0079] For example, the control unit (150) can select accurate data using the following anode-cathode gap data selection algorithm. First, the dimensions of the cathode (3) in each of the upper image of the unit cell obtained from the second vision unit and the lower image of the unit cell obtained from the first vision unit are compared to determine if the difference is 0.12 mm or more. Second, the contrast value of the cathode (3) in the upper image is 10 or less. Third, the degree of proximity between the edge of the cathode (3) in the upper image and the sealed edge of the separator (326) is checked. Fourth, the degree of proximity between the edge of the cathode (3) in the lower image and the sealed edge of the separator (326) is checked. Fifth, the contrast value of the cathode (3) in the lower image is 20 or less. Through this algorithm, the control unit (150) can select and use the most accurate anode-cathode gap data.

[0080] The control unit (150) can calculate cathode alignment position data using positive alignment position data measured by the alignment vision unit (120) and selected interval data. For example, if the control unit (150) adds the distance between the positive (2) side and the negative (3) side at the positive side of the positive alignment position data, the position of the negative side of the negative alignment position data can be calculated.

[0081] The stacking section (160) is configured to stack unit cells (1) using calculated cathode alignment position data. The stacking section (160) may include a stacking table (162). The stacking table (162) can stack unit cells (1) sequentially.

[0082] Meanwhile, according to another embodiment of the present invention, the control unit (150) can omit the accuracy selection process of the anode-cathode gap data described above and calculate the cathode (3) alignment position data using the second gap data derived from the position of the cathode (3) side measured by the first vision unit (111) located below the unit cell (1) and the position of the anode (2) side measured by the second vision unit (112) located above the unit cell (1), and the anode alignment position data measured by the alignment vision unit (120). This method can calculate more accurate cathode alignment position data when the second vision unit is advantageous for measuring the anode more accurately and the first vision unit is advantageous for measuring the position of the cathode more accurately.

[0083] Meanwhile, according to one embodiment of the present invention, the electrode assembly manufacturing device (100) may further include a stacking vision unit (130) configured to measure the alignment position of the anode (2) of the stacked unit cell (1). In this case, the control unit (150) can calculate the alignment position data of the cathode of the stacked unit cell (1) using the anode alignment position data and the spacing data measured by the stacking vision unit (130).

[0084] Additionally, the control unit (150) can perform an anode-cathode overhang inspection by comparing the anode alignment position data and the calculated cathode alignment position data for each of the stacked unit cells (1). Here, the overhang inspection determines that a defect has occurred because the anode (2) is positioned outside the cathode (3) when the gap between the cathode and anode is 0 or negative in order to check the alignment state of the unit cell.

[0085] According to another embodiment of the present invention, the control unit (150) may be configured to transmit interval data through a PMAC (Programmable Multi-Axis Controller) (180). The PMAC (180) is a controller capable of precisely controlling motion of multiple axes, thereby enabling more accurate stacking control.

[0086] In this way, the electrode assembly manufacturing device (100) of the present invention can stack unit cells (1) based on the cathode (3) through precise measurement and calculation.

[0087] Referring to FIG. 7, an electrode assembly (1) can be manufactured with a width (W2) smaller than the total width (W1) of a conventional electrode assembly. Accordingly, the present invention has the effect of improving the energy density of a secondary battery. In addition, the quality of the product can be significantly improved through real-time overhang inspection while the stacking part (160) of the present invention stacks unit cells.

[0088] Hereinafter, a method for manufacturing an electrode assembly (200) according to one embodiment of the present invention will be described.

[0089] FIG. 8 is a flowchart of a method for manufacturing an electrode assembly (200) according to one embodiment of the present invention.

[0090] Referring to FIGS. 4 to 8, a method for manufacturing an electrode assembly (200) according to one embodiment of the present invention includes a preliminary measurement step (M01), a gap data calculation step (M02), a re-measurement step (M03), a cathode alignment position data calculation step (M04), and a stacking step (M05).

[0091] In the preliminary measurement step (M01), at least one vision unit is used to measure the alignment position of the anode (2) and the alignment position of the cathode (3) of the unit cell (1). Specifically, the first vision unit (111) can measure the coordinates of at least two points (P3, P4) on the side of the cathode (3) at the bottom of the unit cell (1). Additionally, the second vision unit (112) can measure the coordinates of at least two points (P1, P2) on each side formed on the anode (2) and the coordinates of at least two points (P3, P4) on each side formed on the cathode (3) at the top of the unit cell (1).

[0092] In the interval data calculation step (M02), the control unit (150) calculates interval data between the anode (2) and the cathode (3) based on the measured data of the anode (2) alignment position and the cathode (3) alignment position. Specifically, the control unit (150) can calculate the first interval data by comparing the position of at least the cathode (3) side measured by the first vision unit (111) with the position of the anode (2) side measured by the second vision unit (112). Additionally, the control unit (150) can calculate the second interval data by comparing the position of the cathode (3) side measured by the second vision unit (112) with the position of the anode (2) side. The control unit (150) can select one interval data by comparing the accuracy of the first interval data and the second interval data.

[0093] In the re-measurement step (M03), the alignment vision unit (120) measures the alignment position of the anode (2) of the unit cell (1). Specifically, the alignment vision unit (120) can measure the coordinates of at least two points (P1, P2) on the anode (2) side of the unit cell (1). Additionally, position data of the anode (2) side can be calculated by connecting the coordinates of the at least two measured points (P1, P2) to each other.

[0094] In the cathode alignment position data calculation step (M04), the control unit (150) calculates cathode alignment position data using the calculated interval data and the anode alignment position data measured in the re-measurement step. Specifically, the control unit (150) can calculate cathode alignment position data using the anode (2) side position data measured by the alignment vision unit (120) and the selected interval data.

[0095] In the stacking step (M05), the stacking part (160) stacks the unit cells (1) using the calculated cathode alignment position data.

[0096] FIG. 9 is a flowchart showing the processes of a method (200) for manufacturing an electrode assembly according to one embodiment of the present invention.

[0097] Referring to FIGS. 4, 8, and 9, the control unit (150) first collects information simultaneously through two paths. One is to collect the alignment position information of the cathode (3) from the first vision unit (111), and the other is to collect the alignment position information of the cathode (3) and the anode (2) together from the second vision unit (112).

[0098] Based on the collected information, the control unit (150) calculates first and second interval data. The first interval data is calculated using only the alignment position information of the cathode (3), and the second interval data is calculated using both the alignment position information of the cathode (3) and the anode (2).

[0099] Next, the control unit (150) selects the more accurate of the calculated first and second interval data. This selection process is performed by comparing and analyzing the accuracy of each data. The selected interval data is determined for use in a subsequent process.

[0100] Immediately before stacking, the control unit (150) collects the alignment position information of the anode (2) again through the alignment vision unit (120). This is to obtain accurate position information before stacking.

[0101] The control unit (150) calculates the cathode (3) alignment position data using the selected interval data, the re-measured anode (2) alignment position information, and the selected interval data.

[0102] Finally, the control unit (150) transmits the calculated cathode (3) alignment position data to the stacking unit (160) and instructs the stacking unit (160) to stack the unit cells (1) based on this.

[0103] Meanwhile, according to one embodiment of the present invention, the method for manufacturing an electrode assembly (200) may further include the step of measuring the alignment position of the anode (2) of the stacked unit cell (1) using a stacked vision unit (130). Additionally, the control unit (150) may calculate the alignment position data of the cathode of the stacked unit cell (1) using the anode alignment position data and the spacing data measured by the stacked vision unit (130).

[0104] Additionally, the control unit (150) may further include a step of performing an anode-cathode overhang inspection by comparing the measured anode alignment position data of each of the stacked unit cells (1) with the cathode alignment position data calculated in the previous step.

[0105] Specifically, the positive-negative overhang inspection may be performed by comparing the positive alignment position data and the positive alignment position data calculated by the control unit (150) using the positive alignment position data and the gap data to check if there is a part where the positive electrode (2) protrudes more than the negative electrode (3).

[0106] According to another embodiment of the present invention, the control unit (150) may be configured to transmit interval data through a PMAC (Programmable Multi-Axis Controller) (180). Data transmission through the PMAC (180) enables more precise and efficient control.

[0107] According to one embodiment of the present invention, a method for manufacturing an electrode assembly may further include an alignment step of aligning the center of the negative electrode (3) of a unit cell (1) with the center of a stacking table (162). This alignment step includes a step of moving the stacking table (162) in the X-axis, Y-axis, and horizontal rotational directions, and the unit cell (1) is moved only in the X-axis direction.

[0108] Additionally, according to one embodiment of the present invention, the control unit (150) may further include a step of determining the accuracy of the interval data by analyzing the upper image and lower image of the unit cell (1) measured in the preliminary measurement step, and a step of performing selection of the interval data according to the determination result.

[0109] Accordingly, the method for manufacturing an electrode assembly (200) of the present invention can stack unit cells (1) based on the cathode (3) through precise measurement and calculation. This has the effect of reducing the overall width of the electrode assembly and improving energy density. In addition, the quality of the product can be significantly improved through real-time overhang inspection.

[0110] FIG. 10 is a partial cross-sectional view showing the appearance of an electrode assembly according to one embodiment of the present invention. FIG. 11 is a plan view showing a secondary battery according to one embodiment of the present invention.

[0111] Referring to FIGS. 10 and 11, the present invention provides a secondary battery comprising an electrode assembly (320) manufactured through an electrode assembly manufacturing device (100) and an electrode assembly manufacturing method (200), and a pouch (360) provided to accommodate the same.

[0112] Specifically, the present invention provides a secondary battery (300) comprising a unit cell (1) manufactured by the secondary battery manufacturing device (100) described above. This secondary battery (300) can provide a secondary battery with high energy density by applying an electrode assembly (320) in which the unit cells manufactured by the secondary battery manufacturing device (100) of the present invention are aligned and stacked with respect to the negative electrode.

[0113] Specifically, the secondary battery (300) includes an electrode assembly (320), an electrolyte (not shown), and a pouch (360).

[0114] Here, the electrode assembly (320) may include a plurality of positive electrodes (321) and negative electrodes (322) as shown in FIG. 10, and a separator (326) interposed between the positive electrodes (321) and the negative electrodes (322). The secondary battery (300) may be provided with a plurality of positive electrode tabs (351) and negative electrode tabs (not shown) provided on each of the plurality of positive electrodes (321) and negative electrodes (322). The secondary battery (300) includes a lead portion (330). Additionally, the lead portion (330) includes a positive electrode lead (331) and a negative electrode lead (333). Each of the plurality of positive electrode tabs (351) and negative electrode tabs (not shown) may be connected to the positive electrode lead (331) and the negative electrode lead (333) through welding or the like. As shown in FIG. 10, the positive tab (351) and the positive lead (331) can form a weld (327) through welding.

[0115] As shown in FIG. 11, the positive lead (331) protrudes outward from the pouch (360), and the negative lead (333) protrudes outward from the pouch (360). The lead portion (330) can electrically connect the electrode assembly (320) and the external circuit.

[0116] The pouch (360) is provided to accommodate the electrode assembly (320). The pouch (360) protects the electrode assembly (320) from the external environment and serves to maintain the electrolyte stably.

[0117] A protective film (340) is provided between the pouch (360) and the lead portion (330). The protective film (340) ensures electrical insulation between the lead portion (330) and the pouch (360). A receiving portion (362) for accommodating an electrode assembly (320) is formed in the pouch (360).

[0118] The preferred embodiments of the present invention described above are disclosed for illustrative purposes only, and those skilled in the art with ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims.

[0119] According to an electrode assembly manufacturing apparatus and manufacturing method according to one embodiment of the present invention, the alignment positions of the anode and cathode of a unit cell are precisely measured using a pre-measurement vision unit and an alignment vision unit, and the unit cells are stacked based on the cathode, thereby reducing the overall width of the electrode assembly and improving the energy density.

Claims

1. In an apparatus for manufacturing an electrode assembly by stacking unit cells, A transfer unit that transfers unit cells; At least one pre-measurement vision unit configured to measure the positive alignment position and the negative alignment position of the unit cell; An alignment vision unit provided to measure the positive alignment position of the unit cells when the unit cells are stacked; A control unit configured to calculate anode and cathode gap data using anode alignment position data and cathode alignment position data measured from the above-mentioned pre-measurement vision unit, and to calculate cathode alignment position data using the gap data and anode alignment position data measured from the above-mentioned alignment vision unit; and An electrode assembly manufacturing apparatus characterized by including a stacking section provided to stack the unit cells using the above-determined cathode alignment position data.

2. In Paragraph 1, The above-mentioned pre-measurement vision unit is, A first vision unit that measures at least two coordinates on the cathode side at the bottom of the unit cell; and An electrode assembly manufacturing apparatus characterized by including a second vision unit that measures at least two coordinates on the sides of the cathode and anode, respectively, at the top of the unit cell.

3. In Paragraph 2, The above control unit is, Calculate first interval data by comparing the position of at least the negative side measured by the first vision unit with the position of the positive side measured by the second vision unit, and The position of the negative side and the position of the positive side measured by the second vision unit are compared to calculate the second interval data, An electrode assembly manufacturing apparatus characterized by being configured to select one interval data by comparing the accuracy of the first interval data and the second interval data.

4. In Paragraph 3, The above control unit is, An electrode assembly manufacturing apparatus characterized by being configured to calculate cathode alignment position data using positive alignment position data measured by the above alignment vision unit and the above selected interval data.

5. In Paragraph 2, The above electrode assembly manufacturing device further includes a stacking vision unit configured to measure the anode alignment position of a stacked unit cell, and The above control unit is, Calculate the cathode alignment position data of the stacked unit cell using the anode alignment position data measured by the above stacked vision unit and the above gap data, and An electrode assembly manufacturing apparatus characterized by being configured to perform an anode-cathode overhang inspection by comparing the measured anode alignment position data and the calculated cathode alignment position data of each of the stacked unit cells.

6. In Paragraph 1, An electrode assembly manufacturing device characterized by the above-described control unit being configured to transmit the interval data through a PMAC (Programmable Multi-Axis Controller).

7. In Paragraph 1, The above transfer unit is, It includes a conveyor belt configured to suck up the upper part of the unit cell through an adsorption part and transport it in an attached state, and An electrode assembly manufacturing device characterized in that the adsorption portion has an area smaller than the anode of the unit cell.

8. In Paragraph 1, It further includes an alignment part provided to align the center of the negative electrode of the unit cell with the center of the stacking table, and The above alignment unit is, The above stacking table is configured to move in the X-axis and Y-axis directions and horizontally, and An electrode assembly manufacturing device characterized in that the above unit cell is configured to be movable only in the X-axis direction by the above transfer unit.

9. A method for manufacturing an electrode assembly by stacking unit cells, A preliminary measurement step of measuring the positive alignment position and the negative alignment position of the unit cell using at least one vision unit; A gap data calculation step in which a control unit calculates gap data between an anode and a cathode based on the measured data of the anode alignment position and the cathode alignment position; A re-measurement step in which an alignment vision unit measures the positive alignment position of the unit cell; A cathode alignment position data calculation step in which the control unit calculates cathode alignment position data using the calculated interval data and the anode alignment position data measured in the re-measurement step; and A method for manufacturing an electrode assembly characterized by including a stacking step in which a stacking portion stacks the unit cells using the calculated cathode alignment position data.

10. In Paragraph 9, The above preliminary measurement step is, A first vision unit measuring the coordinates of at least two points on the cathode side at the bottom of the unit cell; and A method for manufacturing an electrode assembly characterized by including the step of a second vision unit measuring the coordinates of at least two points on the sides of the cathode and anode, respectively, at the top of the unit cell.

11. In Paragraph 10, The above interval data calculation step is, The control unit calculates first interval data by comparing the position of at least the negative side measured by the first vision unit with the position of the positive side measured by the second vision unit; The control unit calculates second interval data by comparing the position of the negative side and the position of the positive side measured by the second vision unit; and A method for manufacturing an electrode assembly characterized by including the step of the control unit comparing the accuracy of the first interval data and the second interval data to select one interval data.

12. In Paragraph 11, The above re-measurement step is, A step in which an alignment vision unit measures the coordinates of at least two points on the positive side of the unit cell; and The method includes a step of calculating position data of the positive side by connecting the coordinates of at least two points measured above; The above step of calculating cathode alignment position data is, A method for manufacturing an electrode assembly characterized by including a step in which the control unit calculates cathode alignment position data using the position data of the positive side measured by the alignment vision unit and the selected interval data.

13. In Paragraph 9, A step of measuring the anode alignment position of a stacked unit cell using a stacked vision unit; and A method for manufacturing an electrode assembly, further comprising the step of performing an anode-cathode overhang inspection by comparing the measured anode alignment position data and the calculated cathode alignment position data of each of the stacked unit cells with the control unit.

14. In Paragraph 13, The above anode-cathode overhang inspection is, A method for manufacturing an electrode assembly characterized by the control unit comparing the cathode alignment position data calculated using the anode alignment position data and the spacing data of each of the stacked plurality of unit cells with the anode alignment position data to determine whether there is a part where the anode protrudes more than the cathode.

15. In Paragraph 9, It further includes an alignment step of aligning the center of the negative electrode of the unit cell with the center of the stacking table, and The above alignment step is, The step of moving the stacking table in the X-axis and Y-axis directions and horizontally rotated, A method for manufacturing an electrode assembly characterized in that the above unit cell moves only in the X-axis direction.

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