Pressing device for secondary battery formation capable of monitoring pressing force in real time and pressing method thereof

Abstract

The present invention relates to a pressing device and method for forming a secondary battery, which can monitor the pressing force for forming the battery in real time by monitoring the contact area between a pressing plate and the battery in real time, in order to solve the problem of lithium precipitation due to changes in pressing uniformity caused by the battery contact area not being confirmed when pressing the battery in the formation process, which is one of the manufacturing processes for the secondary battery.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0134790, filed October 11, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a pressing device and a pressing method for forming a secondary battery, capable of monitoring a pressing force in real time. More particularly, the present invention relates to a pressing device and a pressing method for forming a secondary battery, capable of monitoring a pressing force in real time so that pressing for formation can be performed while monitoring the contact area between a pressing plate and a battery in real time, in order to solve a problem in which lithium deposition occurs due to changes in pressing uniformity caused by an undetected contact area of ​​the battery during a formation process, which is one of the manufacturing processes of a secondary battery. [Background technology]

[0003] Generally, secondary batteries can be classified into cylindrical, prismatic, pouch, etc., depending on their shape. Among them, pouch-type secondary batteries are shaped using a pouch exterior material made of a multilayer film of a metal layer (foil) and a synthetic resin layer coated on the top and bottom of the metal layer, which significantly reduces the weight of the battery compared to cylindrical or prismatic types that use metal cans. This allows for the battery to be lighter, and it has the advantage of being flexible and adaptable to various shapes, which has attracted much attention.

[0004] Such pouch-type secondary batteries contain electrode assemblies in a stacked state. Electrode tabs and electrode leads are connected to the electrode assemblies, and the electrode leads protrude from the pouch exterior. The electrode leads are electrically connected to an external device through contact with the external device, thereby receiving power from the external device.

[0005] The manufacturing process of such a battery cell can be divided into three processes, including an electrode manufacturing process, an assembly process, and an activation process.

[0006] The electrode manufacturing process refers to a process of mixing materials required for manufacturing a positive electrode and a negative electrode in appropriate proportions, coating an aluminum foil with a positive electrode mixture for the positive electrode, and coating a copper foil with a negative electrode mixture for the negative electrode, pressing the foil to a certain thickness using a roll press to flatten it, and then performing a slitting process to cut the foil to the size of the electrode.

[0007] In addition, the assembly process involves stacking cathodes, separators, and anodes alternately in multiple layers after notching to remove unnecessary parts from the electrodes, and then folding the stack multiple times according to the battery capacity (a stack and folding process) or winding the electrodes and separators into a roll, packaging them in aluminum film packaging, adding electrolyte, and sealing them in a vacuum.

[0008] The final activation process involves repeatedly charging and discharging the assembled battery cells to activate them, and then performing a degassing process to release gases generated in the battery cells during activation. A formation jig is used to press the battery cells during this activation process.

[0009] A pouch-type secondary battery is manufactured through a cell assembly process and a battery activation process. In the battery activation step, the secondary battery cell is mounted in a charge / discharge device and charged and discharged under conditions required for activation. This process of performing predetermined charge / discharge using a charge / discharge device for battery activation is called a formation process.

[0010] During or after the battery cell manufacturing process described above, sliding or tapering of the electrode ends can occur, resulting in thickness deviations in the center and tab portions of the battery cell. This can also cause uneven pressure during the process using the formation jig, weakening the adhesive strength between the positive and negative electrodes in the bi-cell, resulting in separation, which can lead to lithium precipitation problems.

[0011] Therefore, there is a need for development of a technology for monitoring whether a uniform pressure is applied to the battery cell when the battery cell is pressed by a formation jig used in the activation process of the battery cell manufacturing process.

[0012] Japanese Patent Application Laid-Open No. 2022-104809 discloses a configuration including a second end plate and a pressure plate located on both ends of a tray that accommodates battery cells, and a partition located inside the tray. However, unlike the real-time pressure monitoring technology of the present invention, the pressure sensing device of this patent is not formed individually on the cell plate located between the cells, but rather in the central region of each cell assembly, so there is a difference in its configuration.

[0013] Chinese Patent Publication No. 217387245 discloses a structure for determining the pressure status in real time using a pressure sensor, but this differs from the structure of the present invention in that each of the components corresponding to the cell plates in the formation process includes a thin-film type electronic pressure-sensitive paper to constantly monitor the cell contact area.

[0014] Korean Patent Publication No. 10-2023-0053970 discloses a configuration in which a pair of pressure plates sandwiching a secondary battery includes a body part and an outer shell part, and a silicone pad is formed on the pressure plate during the formation process. However, this configuration is different from the technical configuration of the electronic pressure-sensitive paper for monitoring pressure force of the present invention.

[0015] Korean Patent Publication No. 10-2023-0102104 discloses a configuration for detecting pressure distribution in real time using an electronic decompression sheet, and for displaying pressure information sensed by the electronic decompression sheet on a bonding status indicator (monitor). However, the difference lies in the configuration for detecting pressure information of a substrate deposition apparatus, not the formation process of the present invention.

[0016] Therefore, during the formation process, which is one of the manufacturing processes for secondary batteries, batteries must be pressed uniformly. However, in order to solve the problem of lithium precipitation due to changes in pressing uniformity caused by an inability to check the contact area where the battery is pressed, there is a need to develop a pressing device and pressing method for secondary battery formation that can monitor the pressing force in real time so that pressing for formation can be performed while monitoring the contact area between the pressing plate and the battery in real time. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] Japanese Patent Publication No. 2022-104809

[0018] [Patent Document 2] Chinese Patent Publication No. 217387245

[0019] [Patent Document 3] Korean Patent Publication No. 10-2023-0053970

[0020] [Patent Document 4] Korean Patent Publication No. 10-2023-0102104 Summary of the Invention [Problem to be solved by the invention]

[0021] The present invention has been made to solve the above-mentioned problems, and aims to provide a pressing device for secondary battery formation and a pressing method thereof that can monitor the pressing force in real time so that pressing for formation can be performed while monitoring the contact area between the pressing plate and the battery in real time, in order to solve the problem of lithium precipitation due to changes in pressing uniformity when the contact area for pressing the battery is not confirmed during the formation process, which is one of the processes for manufacturing secondary batteries. [Means for solving the problem]

[0022] To achieve this object, the present invention provides a pressing device for secondary battery formation that includes a plurality of pressing plates, a first main plate and a second main plate that are respectively arranged on the outermost sides of the pressing plates and press the batteries housed between the pressing plates, and a drive shaft that fastens the first main plate and the second main plate to each other and moves the first main plate and the second main plate in the x direction, and a thin-film electronic pressure-sensitive paper is provided between the pressing plates.

[0023] The pressure plate may include a body surface facing the battery surface with an area corresponding to the area of ​​the battery in the y and z directions, a silicone pad attached to the outer surface of the body surface, and electronic pressure-sensitive paper attached to the outer surface of the silicone pad.

[0024] The pressure plate may include a body surface facing the battery surface with an area corresponding to the area of ​​the battery in the y and z directions, a silicone pad attached to the outer surface of the body surface, and electronic pressure-sensitive paper attached to the outer surface of the silicone pad.

[0025] The pressure plate may further include a heating pad for heating the battery cells.

[0026] The heating pad may be formed on an outer surface of any one of the main body surface, the silicone pad, and the electronic pressure-sensitive paper.

[0027] The pressure plates are arranged in the x direction and can press or release the pressure on the battery while moving in the x direction so that the distance between them decreases or increases.

[0028] In addition, one side of each of the plurality of electronic pressure-sensitive papers may include a data socket for collecting and transmitting decompression information to a DAQ (Data Acquisition) unit.

[0029] The electronic pressure sensitive paper may also include a central processing unit that displays the magnitude of the pressure applied to the electronic pressure sensitive paper.

[0030] The drive shaft may also include a motor that transmits a pressing force to the first main plate and the second main plate that are linked to the drive shaft, a gear box that is connected to the drive shaft and the motor and rotates to induce forward or reverse rotation of the drive shaft, and a rod cell that presses to the pressing force by the force of the motor.

[0031] The device may also include a battery insertion unit that grips a plurality of the batteries and places the batteries between the pressure plates.

[0032] To achieve this object, the present invention provides a method for measuring the pressure of a secondary battery, which includes a first step of attaching a plurality of thin-film electronic pressure-sensitive papers to the outer surfaces of a plurality of pressure plates, respectively; a second step of arranging a plurality of the batteries between the pressure plates, respectively; a third step of pressing the plurality of batteries while moving the first main plate and the second main plate in the x direction; a fourth step of performing one charge / discharge while maintaining the third step; and a fifth step of monitoring the pressure applied to the thin-film electronic pressure-sensitive papers in the fourth step, wherein in the fifth step, among the plurality of batteries, batteries that have a different pressure applied to the thin-film electronic pressure-sensitive papers from the other batteries are classified into a rework group.

[0033] The pressure plate may include a body surface facing the battery surface with an area corresponding to the area of ​​the battery in the y and z directions, a silicone pad attached to the outer surface of the body surface, and electronic pressure-sensitive paper attached to the outer surface of the silicone pad.

[0034] The present invention can also be provided in the form of various combinations of means for solving the above problems. [Effects of the Invention]

[0035] The pressing device for secondary battery formation and pressing method thereof, which can monitor pressing force in real time, of the present invention can monitor pressing force in real time while pressing multiple batteries in both directions, thereby reducing the movement distance of each plate and thereby reducing pressure deviation between each battery.

[0036] In addition, pressure-sensitive paper was used to check the contact area for pressing existing batteries, but this can be verified only once when setting up the initial pressing device, which has the effect of improving areas where constant monitoring is not possible.

[0037] In addition, during the pressing process for forming a plurality of batteries, batteries that are not pressed uniformly can be selected, and after the pressing process is completed, the pressing uniformity can be improved by performing the rework. [Brief explanation of the drawings]

[0038] [Figure 1] 1 is a block diagram of a pressing device for forming a battery including an electronic pressure-sensitive paper before a pressing process according to an embodiment of the present invention;

[0039] [Figure 2] 1 is a block diagram of a pressing device for forming a battery during a pressing process including an electronic pressure-sensitive paper according to an embodiment of the present invention;

[0040] [Figure 3] 1 is a diagram showing the configuration of a pressure plate channel of a pressure device for formation including electronic pressure-sensitive paper according to a first embodiment of the present invention;

[0041] [Figure 4] FIG. 10 is a structural diagram of a pressure plate channel of a formation pressure device including electronic pressure-sensitive paper according to a second embodiment of the present invention.

[0042] [Figure 5] FIG. 10 is a structural diagram of a pressure plate channel of a formation pressure device including an electronic pressure-sensitive paper and a heating pad according to a third embodiment of the present invention.

[0043] [Figure 6] 10 is a graph showing the results of measuring the pressure force over time when electronic pressure-sensitive paper is applied.

[0044] [Figure 7] 10 is a table showing the results of an experiment on the reliability and repeatability of pressing force measurement using electronic pressure-sensitive paper.

[0045] [Figure 8] FIG. 10 shows the results of measuring the consistency of pressing force measurements between 9-channel sensors.

[0046] [Figure 9] FIG. 10 shows the results of measuring the consistency of pressure measurements between 36-channel sensors.

[0047] [Figure 10] 10 is a photograph showing the change in appearance of the electronic pressure-sensitive paper before and after a pressure durability experiment.

[0048] [Figure 11] FIG. 10 is a configuration diagram of a formation pressing device including a battery insertion unit according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0049] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person of ordinary skill in the art to easily carry out the present invention. However, in describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0050] Furthermore, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0051] Furthermore, in this specification, limitations or additions to a certain embodiment are not only applicable to the specific embodiment, but are also applicable to other embodiments.

[0052] Furthermore, throughout the description of the present invention and the claims, the singular includes the plural unless otherwise stated.

[0053] The invention will now be explained with reference to the drawings and in conjunction with detailed embodiments.

[0054] FIG. 1 is a block diagram of a pressing device for forming a battery including an electronic pressure-sensitive paper before a pressing process according to an embodiment of the present invention.

[0055] The pressing device 100 for secondary battery formation includes a plurality of pressing plates 110, a first main plate 120a and a second main plate 120b that are respectively arranged on the outermost sides of the pressing plates 110 and press the batteries accommodated between the pressing plates 110, and a drive shaft 130 that fastens the first main plate 120a and the second main plate 120b to each other and moves the first main plate 120a and the second main plate 120b in the x direction, and a pressing device for secondary battery formation can be provided that has thin-film electronic pressure-sensitive paper 140 between the pressing plates 110.

[0056] The battery housed between the pressure plates 110 may be a pouch-type battery cell. For example, the pouch-type battery cell is a pouch-type unit cell in which an electrode assembly having a positive electrode / separator / negative electrode structure is embedded in a laminate sheet outer casing and connected to electrode leads formed on the outside of the casing. The electrode leads are drawn out to the outside of the sheet and may extend in the same or opposite directions.

[0057] The shape of the pressure plate 110 is not limited as long as it can transmit a pressure to the battery, and the pressure plate 110 can be configured to correspond to the shape of the battery inserted with the y direction as the longitudinal direction.

[0058] The pressure plate 110 has a generally hexahedral shape and forms a certain space inside to accommodate a number of pouch-type batteries in the longitudinal direction. The frame may include a bottom surface and side walls on both sides of the bottom surface to support the accommodated batteries. The side walls may be formed on one side and the other side in the direction in which the number of battery cells are accommodated. Furthermore, the frame may have an open top to allow the battery cells to be removed and installed.

[0059] The pressure plate 110 may preferably have a rectangular shape.

[0060] It is known that when the position of one end of a secondary battery is 300 mm from the center (origin 0), a sudden drop in pressure occurs at the 200 mm point. Also, it can be seen that a sudden drop in pressure occurs at both ends of a secondary battery that has undergone a formation process using a conventional secondary battery charging / discharging device.

[0061] Therefore, the pressure plate 110 may have a shape in which the thickness increases from the center toward each corner.

[0062] The pressing device 100 for secondary battery formation includes a motor 170 that transmits pressing force to the first main plate 120a and the second main plate 120b that are linked to the drive shaft 130, a gear box 180 that is connected to the drive shaft 130 and the motor 170 and rotates to induce forward or reverse rotation of the drive shaft, and a rod cell 190 that presses up to the pressing force using the force of the motor 170.

[0063] FIG. 2 is a block diagram of a pressing device for forming a battery during a pressing process including an electronic pressure-sensitive paper according to an embodiment of the present invention.

[0064] The battery pack includes a plurality of batteries housed between pressure plates 110 formed between a first main plate 120a and a second main plate 120b, and the pressure plates 110 are structured to be movably disposed along a drive shaft 130.

[0065] Here, the pressure plates 110 have fastening holes formed in the area where they are fastened to the drive shaft 130, and the fastening holes are larger in diameter than the drive shaft.

[0066] In another example, a fixed plate may be disposed in the central region of the drive shaft 130. Furthermore, a first pressure sensor and a second pressure sensor may be disposed on both sides of the fixed plate, respectively.

[0067] The fixing plates may be formed in plurality at regular intervals around the center of the driving shaft 130 .

[0068] In yet another example, the pressing plates 110 may be disposed on both sides of the fixed plate so as to be movable along the drive shaft 130 .

[0069] In a specific example, a first pressure sensor and a second pressure sensor are provided between the pressing plate 110 and the fixed plate and between the other pressing plate 110 and the fixed plate, respectively.

[0070] Here, the first and second pressure sensors may have a structure in which a fastening hole is formed in an area where the first and second pressure sensors are fastened to the drive shaft, and the fastening hole may have a diameter larger than that of the drive shaft.

[0071] Furthermore, the drive shaft 130 may include a power generating unit connected to one end of the drive shaft 130 to transmit a rotational force to the drive shaft 130 .

[0072] In one example, the first main plate 120a and the second main plate 120b press against the battery cells housed inside the frame and are disposed at the outermost periphery of the batteries. For example, if 36 batteries are disposed inside the frame, the first main plate 120a may be disposed in front of the first battery cell, and the second main plate 120b may be disposed in front of the 36th battery. The first main plate 120a and the second main plate 120b press against both sides of the batteries as the drive shaft 130 is driven.

[0073] The first main plate 120a and the second main plate 120b may be made of a metal material having high mechanical rigidity, or may be made of any other material having excellent mechanical rigidity, such as reinforced plastic, reinforced ceramic, or reinforced glass, in addition to metal.

[0074] FIG. 3 is a diagram showing the structure of a pressure plate channel of a pressure device for formation including electronic pressure-sensitive paper according to a first embodiment of the present invention.

[0075] The pressure plate may also include a body surface 111 facing the battery surface with an area corresponding to the area of ​​the battery 1 in the y and z directions, a silicone pad 112 attached to the outer surface of the body surface 111, and the electronic pressure-sensitive paper 140 attached to the outer surface of the silicone pad 112.

[0076] FIG. 4 is a diagram showing the structure of a pressure plate channel of a pressure device for formation including electronic pressure-sensitive paper according to a second embodiment of the present invention.

[0077] In addition, the pressure plate may include a main body surface 111 facing the battery surface with an area corresponding to the area of ​​the battery 1 in the y and z directions, an electronic pressure-sensitive paper 140 attached to the outer surface of the main body surface 111, and the silicone pad 112 attached to the outer surface of the electronic pressure-sensitive paper 140.

[0078] FIG. 5 is a diagram showing the structure of a pressure plate channel of a formation pressure device including an electronic pressure-sensitive paper and a heating pad according to a third embodiment of the present invention.

[0079] The pressure plate may further include a heating pad for heating the battery 1 .

[0080] The heating pad is formed on at least one surface of the pressure plate and supplies heat to the pressure plate.

[0081] Silicon pads are formed on both sides of the pressure plate on which the heating pads are formed, and press the secondary battery.

[0082] The heating pad may be formed on an outer surface of any one of the main body surface, the silicone pad, and the electronic pressure-sensitive paper.

[0083] The pressure plates are arranged in the x direction and can press or release the pressure on the battery while moving in the x direction so that the distance between them decreases or increases.

[0084] In addition, one side of the plurality of electronic pressure-sensitive papers 140 may include a data socket 141 for collecting and transmitting decompression information to a DAQ (Data Acquisition) unit 150 .

[0085] Since one or more electronic pressure-sensitive papers are formed on both sides of the pressing plate, multiple pressing force data can be continuously generated during the pressing process.

[0086] Therefore, a device is required to collect and monitor the pressing force data generated by each secondary battery positioned between the pressing plates.

[0087] A DAQ unit 150 is provided to collect data generated by each electronic pressure-sensitive paper, and a data socket 141 is required to transmit the pressure data generated by each electronic pressure-sensitive paper 140 to the DAQ unit 150.

[0088] The DAQ unit 150 collects the pressing force data generated by the battery 1 through multiple channels. When the formation pressing device accommodates 36 batteries in one pressing process, the DAQ unit 150 can preferably have 36 pressing force data collection channels.

[0089] The electronic pressure sensitive paper may also include a central processing unit 160 that displays the magnitude of pressure applied to the electronic pressure sensitive paper.

[0090] The pressure data collected by the DAQ unit 150 can be transmitted to a central processing unit 160. The central processing unit may include software for visualizing the pressure data, an image display device for displaying the visualized pressure data, and a transmission device for transmitting the pressure data to the outside.

[0091] When the pressing process of the formation pressing device is performed, the pressing condition of the battery generated by the pressing process can be confirmed from the pressing force data of each battery accumulated in real time.

[0092] Example 1

[0093] Repeatability experiments were carried out to measure the pressing force using electronic pressure-sensitive paper.

[0094] The pressing force was 2,837 kgf, and the number of repetitions was 1,055. The experiment was conducted using a JIG02-27 channel device with 30 seconds of pressing and 90 seconds of waiting. The pressing force was measured five times on a plate balance before and after the experiment and compared.

[0095] FIG. 6 is a graph showing the results of measuring the pressure force over time when the electronic pressure-sensitive paper was applied.

[0096] As the number of measurements increased over time, the pressure value increased, and the measurement error increased. The measurement error rate ranged from a minimum of 2.25% to a maximum of 22.37%.

[0097] Example 2

[0098] An experiment was conducted to verify the reliability and repeatability of pressure measurement using electronic pressure sensitive paper.

[0099] Ten sensors were used, and the experimental channels were JIG01-9CH and JIG01-36CH. Each sensor was pressed five times. The pressing force was 2,837 kgf. The pressing force was measured using a plate balance before and after the experiment and compared.

[0100] Figure 7 shows the experimental results of the reliability and repeatability of pressure measurement using electronic pressure-sensitive paper.

[0101] The average pressing force before the experiment was 2,727.6 kgf, and the average pressing force after the experiment was 2,738 kgf. The change in pressing force after the experiment was 11 kgf, and the error rate was confirmed to be 0.4%.

[0102] Example 3

[0103] The consistency between sensors of pressure applied to electronic pressure-sensitive paper was tested.

[0104] Ten sensors were used, and the experimental channels were JIG01-9CH and JIG01-36CH. Each sensor was pressed five times. The pressing force was 2,837 kgf. The pressing force was measured using a plate balance before and after the experiment and compared.

[0105] After performing the calibration, consistency was confirmed based on 2,837 kgf.

[0106] Figure 8 shows the consistency of the pressure measurements between the nine channel sensors. The minimum and maximum values ​​were 2,786 kgf and 2,864 kgf, respectively, with an average of 2,843.7 kgf. The maximum deviation (%RAD) from the mean was 2.03%, and the relative standard deviation (%RSD) was 0.56%.

[0107] Figure 9 shows the consistency of the pressure measurements between the 36-channel sensors. The minimum and maximum values ​​were 2,887.1 kgf and 3,053.1 kgf, respectively, with an average of 2,957.1 kgf. The maximum deviation (%RAD) was 3.24%, and the relative standard deviation (%RSD) was 1.31%.

[0108] Example 4

[0109] A durability test was conducted on the electronic pressure-sensitive paper. A single cell durability test was conducted against the pressure used. The pressure used for durability verification was 10 kgf / cm. 2 The weight used to verify the presence or absence of damage before and after pressing was 15 kgf, the pressing time was 8 seconds, and the rest time was 1.7 seconds. The measurement target was 10,000 times, the measurement sensor was SFC5813, and one node was used. The pressing area was 1 cm 2 is.

[0110] The test piece was periodically pressed with 10 kgf, and when the test piece was pressed with 10 kgf, it was pressed with 15 kgf in the section where changes due to drift appeared to check for damage.

[0111] Figure 10 is a photograph showing the change in appearance of the electronic pressure-sensitive paper before and after the pressure durability experiment.

[0112] In the photographs of the electronic pressure-sensitive paper before the experiment (a) and after the experiment (b), no particular damage was observed after the experiment other than slight external indentations.

[0113] FIG. 11 is a diagram showing the configuration of a formation pressing device including a battery insertion unit according to a fourth embodiment of the present invention.

[0114] The batteries inserted between the pressure plates must be inserted in the same position.

[0115] Therefore, a battery insertion unit is required that can grip a plurality of batteries in the same manner and then position them in the same position between the respective pressing plates.

[0116] The battery insertion unit may include a gripper for gripping the battery, a moving unit for moving the battery insertion unit, a power supply unit for supplying power to the battery insertion unit, and a sensing unit for sensing the positions of the battery insertion unit and the formation pressing jig.

[0117] The gripper may have a shape capable of gripping one battery, and one or more grippers may be formed.

[0118] The sensing unit may be a vision sensor.

[0119] When positioning the battery between the pressure plates using the pressure information of the electronic pressure-sensitive paper, the position of the battery can be adjusted.

[0120] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content.

[0121] Although the present invention has been described in detail above based on representative embodiments, those skilled in the art will understand that various modifications can be made to the above-described embodiments without departing from the scope of the present invention.

[0122] Therefore, the scope of the present invention should not be determined solely by the described embodiments, but should be determined not only by the claims below, but also by equivalents to the claims. [Explanation of symbols]

[0123] 1 battery

[0124] 100 Pressing device

[0125] 110 Pressing plate

[0126] 111 Main unit surface

[0127] 112 Silicone Pad

[0128] 120a 1st main plate

[0129] 120b Second main plate

[0130] 130 drive shaft

[0131] 140 Electronic Pressure-Sensitive Paper

[0132] 141 Data Socket

[0133] 150 DAQ (Data acquisition) units

[0134] 160 Central Processing Unit

[0135] 170 motor

[0136] 180 gearbox

[0137] 190 rod cells

[0138] 200 Battery Input Unit

Claims

1. A plurality of pressure plates; a first main plate and a second main plate, each disposed on the outermost side of the pressing plate, for pressing a battery housed between the pressing plates; a drive shaft that fastens the first main plate and the second main plate to each other and moves the first main plate and the second main plate in an x ​​direction, The pressing device for secondary battery formation is provided with a thin-film type electronic pressure-sensitive paper between the pressing plates.

2. The pressing plate is a main body surface facing the battery surface and having an area corresponding to the area of ​​the battery in the y direction and the z direction; a silicone pad attached to the outer surface of the body; an electronic pressure-sensitive paper attached to the outer surface of the silicon pad; The pressing device for secondary battery formation according to claim 1 , comprising:

3. The pressing plate is a main body surface facing the battery surface and having an area corresponding to the area of ​​the battery in the y direction and the z direction; a silicone pad attached to the outer surface of the body; an electronic pressure-sensitive paper attached to the outer surface of the silicon pad; The pressing device for secondary battery formation according to claim 1 , comprising:

4. 4. The pressing device for secondary battery formation according to claim 2, wherein the pressing plate further includes a heating pad for heating the battery cells.

5. The pressing device for secondary battery formation according to claim 4 , wherein the heating pad is formed on an outer surface of any one of the main body surface, the silicon pad, and the electronic pressure-sensitive paper.

6. 2. The pressing device for secondary battery formation according to claim 1, wherein the pressing plates are arranged in an x-direction and press or release the pressure on the batteries while moving in the x-direction so that the separation distance between the pressing plates decreases or increases.

7. 4. The pressing device for secondary battery formation according to claim 2, further comprising a data socket on one side of the plurality of electronic pressure-sensitive papers for collecting and transmitting decompression information to a DAQ (Data Acquisition) unit.

8. 4. The pressing device for secondary battery formation according to claim 2, further comprising a central processing unit for displaying the magnitude of the pressing force applied to the electronic pressure-sensitive paper.

9. a motor that transmits a pressing force to the first main plate and the second main plate, the motor being interlocked with the drive shaft; a gearbox connected to the drive shaft and the motor, and configured to rotate and induce forward or reverse rotation of the drive shaft; The pressing device for secondary battery formation according to claim 1 , further comprising: a rod cell that presses to a pressing force by the force of the motor.

10. The pressing device for secondary battery formation according to claim 1 , further comprising a battery insertion unit that grips a plurality of the batteries and places the batteries between the pressing plates.

11. A method for measuring a pressing force on a battery using the pressing device for secondary battery formation according to claim 1, comprising: a first step of attaching a plurality of thin-film electronic pressure-sensitive papers to the outer surfaces of the plurality of pressure plates, respectively; a second step of placing a plurality of the batteries between the pressing plates; a third step of pressing the plurality of batteries while moving the first main plate and the second main plate in the x direction; A fourth step of performing one charge / discharge while maintaining the third step; a fifth step of monitoring the pressure applied to the thin-film type electronic pressure-sensitive paper in the fourth step; Including, In the fifth step, the method for measuring the pressure applied to the thin-film type electronic pressure-sensitive paper is classified into a rework group among the plurality of batteries, if the pressure applied to the thin-film type electronic pressure-sensitive paper is different from that of the other batteries.

12. The pressing plate is a main body surface facing the battery surface and having an area corresponding to the area of ​​the battery in the y direction and the z direction; a silicone pad attached to the outer surface of the body; an electronic pressure-sensitive paper attached to the outer surface of the silicon pad; The battery pressing force measuring method according to claim 11, comprising:

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