Electrolyte injection device and electrolyte injection method using the same

Abstract

An electrolyte injection device according to one embodiment of the present invention is an electrolyte injection device that injects electrolyte into a cell case, and includes an upper plate having a built-in hopper that injects electrolyte into the cell case from above, a lower plate having a mounting hole on which the lower surface of the cell case is placed, and an elastic portion located on the lower side of the lower plate at a position corresponding to the mounting hole and compressed in response to pressure applied to the lower surface of the cell case, and a sensor portion for measuring the pressure applied to the lower surface of the cell case is located on the upper side of the elastic portion.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0108084 filed on August 18, 2023, and Korean Patent Application No. 10-2024-0090145 filed on July 9, 2024, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to an electrolyte injection device and an electrolyte injection method using the same, and more particularly to an electrolyte injection device for injecting an electrolyte into a cell case in a battery cell manufacturing process and an electrolyte injection method using the same. [Background technology]

[0003] Demand for secondary batteries is rapidly increasing as they are attracting much attention not only for mobile devices such as mobile phones, digital cameras, and laptop computers, but also as an energy source for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0004] Secondary batteries are classified according to the shape of the battery case into cylindrical batteries and prismatic batteries, in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch batteries, in which the electrode assembly is housed in a pouch-shaped case made of an aluminum laminate sheet.

[0005] In addition, electrode assemblies are typically classified into jelly roll (wound) electrode assemblies in which long sheet-shaped positive and negative electrodes are wound with a separator interposed therebetween; stack (lamination) electrode assemblies in which a plurality of positive and negative electrodes cut into predetermined sizes are stacked in sequence with a separator interposed therebetween; and stack / folding electrode assemblies in which stack-type unit cells are wound with a long separator interposed therebetween.

[0006] During the battery cell manufacturing process, an electrode assembly is sealed in a specified case together with an electrolyte. In the case of cylindrical batteries, a jelly-roll-type electrode assembly is inserted into a metal can and electrolyte is injected. If the metal can is tilted or the sealing member connected to the metal can is damaged, the injected electrolyte may leak out. However, there is no way to check for tilted metal cans or damaged sealing members during the process, which leads to the persistent production of defective products. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to prevent leakage of electrolyte by detecting in advance whether or not there is an abnormality when injecting electrolyte into a cell case of a battery cell. [Means for solving the problem]

[0008] An electrolyte injection device according to one embodiment of the present invention is an electrolyte injection device that injects electrolyte into a cell case, and includes an upper plate having a built-in hopper that injects electrolyte into the cell case from above, a lower plate having a mounting hole on which the lower surface of the cell case is placed, and an elastic portion located on the lower side of the lower plate at a position corresponding to the mounting hole and compressed in response to pressure applied to the lower surface of the cell case, and a sensor portion for measuring the pressure applied to the lower surface of the cell case is located on the upper side of the elastic portion.

[0009] The electrolyte injection device may further include a sealing part that seals a gap between an upper surface of the cell case and a lower surface of the hopper.

[0010] The sensor unit may be disposed to correspond to a periphery of the lower surface of the cell case.

[0011] The sensor unit may include a surface pressure sensor.

[0012] The measurement values ​​from the sensor unit include pressure values ​​corresponding to each position, and it can be determined whether or not an abnormal state has occurred based on the measurement values.

[0013] The abnormal state may include a first abnormal state in which the bottom surface of the cell case and the bottom plate form an acute angle, and a second abnormal state in which the sealing state between the top surface of the cell case and the top plate is incomplete.

[0014] The occurrence of the abnormal state can be determined based on whether the calculation result of the measurement value satisfies a predetermined condition.

[0015] The predetermined conditions may include a first condition and a second condition.

[0016] The sensor unit includes a plurality of sub-sensors, and the predetermined condition includes a first condition, and the first condition can be determined to be satisfied when the difference between the sum of the measurement values ​​obtained from the plurality of sub-sensors and a first reference value is within a predetermined range.

[0017] The sensor unit includes a plurality of sub-sensors, and the predetermined condition includes a second condition, and the second condition can be determined to be satisfied when the relative standard deviation of the measurement values ​​obtained from the plurality of sub-sensors is smaller than a second reference value.

[0018] An electrolyte injection method according to another embodiment of the present invention is performed using the above-mentioned electrolyte injection device and includes the steps of placing a cell case in a mounting hole of a lower plate, fixing the positions of an upper plate located above the cell case and the lower plate on which the cell case is placed, measuring the pressure formed on the lower surface of the cell case using a sensor unit to obtain a measurement value, determining whether an abnormal state has occurred based on the measurement value, and injecting electrolyte into the inside of the cell case if it is determined that the abnormal state has not occurred.

[0019] The step of re-fixing the positions of the upper plate and the lower plate may be included if it is determined that the abnormal state has occurred.

[0020] After the step of re-fixing the positions of the upper plate and the lower plate, the step of determining whether the abnormal state has occurred may be performed again.

[0021] After the step of determining whether or not the abnormal state has occurred, the method may further include a step of comparing a predetermined number of times with the number of repetitions if it is determined that the abnormal state has occurred, and the number of repetitions may be increased by 1 by performing the re-fixing step.

[0022] If the number of repetitions is less than the preset number, the re-fixing step may be performed.

[0023] If the number of repetitions is equal to or greater than the preset number, a step of checking the state of a sealing portion located under the upper plate may be performed.

[0024] The step of determining whether an abnormal state has occurred may include determining whether a calculation result of the measurement value satisfies a first condition.

[0025] The step of determining whether an abnormal state has occurred may further include determining whether a calculation result of the measurement value satisfies a second condition. [Effects of the Invention]

[0026] According to one aspect of the present invention, by detecting abnormalities in advance when injecting an electrolyte during the manufacturing process of a cylindrical battery, leakage of the electrolyte can be prevented, thereby minimizing the defective rate.

[0027] In addition, the present invention may have various other effects, some of which will be described in each embodiment, but explanations of effects that can be easily inferred by those skilled in the art will be omitted. [Brief explanation of the drawings]

[0028] [Figure 1]1 is a side view of an electrolyte injection device according to an embodiment of the present invention; [Figure 2] 2 is a view showing a sensor unit mounted on the electrolyte injection device shown in FIG. 1; [Figure 3] 1 is a diagram showing an abnormal state that may occur when injecting an electrolyte solution. [Figure 4] 1 is a diagram showing an abnormal state that may occur when injecting an electrolyte solution. [Figure 5] 2 is a diagram for explaining how the electrolyte injection device of FIG. 1 determines an abnormal state; [Figure 6] 2 is a flowchart illustrating an electrolyte injection method according to an embodiment of the present invention. [Figure 7] 7 is a flowchart embodying a part of the electrolyte injection method according to FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Terms and words used in this specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as meanings and concepts that correspond to the technical ideas of the present invention, based on the principle that the inventor can appropriately define the concepts of terms to best describe his or her invention. Therefore, it should be understood that the embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical ideas of the present invention, and therefore various equivalents and modifications that can replace them may exist at the time of filing this application.

[0030] In the drawings, the size of each component or specific parts constituting the component may be exaggerated, omitted, or illustrated schematically for convenience and clarity of explanation. Therefore, the size of each component does not fully reflect the actual size. If a detailed description of related well-known functions or configurations is deemed to unnecessarily obscure the gist of the present invention, such description will be omitted.

[0031] Furthermore, when a layer, film, region, plate, etc. is described as being "above" another portion, this should be interpreted as including not only the case where the layer, film, region, plate, etc. is "directly above" the other portion, but also the case where there are other portions therebetween. Conversely, when a layer, film, region, plate, etc. is described as being "directly above" another portion, it can mean that there are no other portions therebetween. Furthermore, being "above" a reference portion means being located above or below the reference portion, and does not necessarily mean being "above" in the direction opposite to gravity. Meanwhile, descriptions of being "above" another portion, as well as descriptions of being "below" another portion, can be understood with reference to the above content.

[0032] Furthermore, throughout the specification, when a part is said to "comprise" a certain element, this does not mean that it excludes other elements and may further include other elements, unless specifically stated to the contrary.

[0033] Also, throughout the specification, "planar" means the part when viewed from above, and "cross-sectional" means the part when viewed from the side, cut vertically.

[0034] An electrolyte injection device according to one embodiment of the present invention will now be described.

[0035] The electrolyte injection device according to an embodiment of the present invention is used to inject an electrolyte into a cell case after inserting an electrode assembly into the cell case during a battery cell manufacturing process.

[0036] 1 is a side view of an electrolyte injection device according to an embodiment of the present invention, and FIG. 2 is a view showing a sensor unit mounted on the electrolyte injection device according to FIG.

[0037] Referring to FIG. 1, the electrolyte injection device 100 of this embodiment may include an upper plate 110 located on the upper side of the cell casing 1, a lower plate 120 corresponding to the lower surface of the cell casing 1, a fixing member 130 that fixes the positions of the upper plate 110 and the lower plate 120 to minimize movement of the cell casing 1, an elastic portion 140 that supports the lower surface of the cell casing 1 below the lower plate 120, and a sensor unit 150 located on the upper surface of the elastic portion 140 and that detects pressure values ​​formed on the lower surface of the cell casing 1.

[0038] Meanwhile, the electrolyte injection device 100 of this embodiment can be used to manufacture a cylindrical battery. Therefore, the cell casing 1 described in this embodiment may have a cylindrical columnar shape. The cell casing 1 may include a circular lower surface and a circumferential surface extending upward from the periphery of the lower surface. Here, the upper surface of the cell casing 1 may be open.

[0039] The upper plate 110 may include a hopper 112 that guides the flow of the electrolyte injected into the cell casing 1. The hopper 112 may have a shape that penetrates the upper plate 110. An electrolyte injection port 114 may be located at an upper portion of the hopper 112, and a sealing portion 116 may be located at a lower portion of the hopper 112.

[0040] The sealing portion 116 seals the gap between the hopper 112 and the top of the cell casing 1, thereby preventing leakage of the electrolyte moving from the hopper 112 to the cell casing 1. The sealing portion 116 may be located at the bottom of the upper plate 110. The sealing portion 116 may have a ring shape, with the top of the sealing portion 116 corresponding to the periphery of the hopper 112 and the bottom of the sealing portion 116 corresponding to the periphery of the top surface of the cell casing 1. The sealing portion 116 may be made of an elastic material to facilitate close contact with the cell casing 1.

[0041] As shown in FIG. 1, the sealing part 116 may have an overall conical shape with the top removed. The sealing part 116 may have a shape in which the diameter of the cross-sectional area increases from the top to the bottom. The diameter of the top of the sealing part 116 may be larger than the diameter of the bottom of the hopper 112. The diameter of the bottom of the sealing part 116 may be larger than the diameter of the top of the cell casing 1. This allows the sealing part 116 to stably seal the gap between the hopper 112 and the cell casing 1.

[0042] Although not specifically illustrated, the hopper 112 may have an inverted conical shape with its top removed. This shape may be formed inside the hopper 112, so that the hopper 112 may appear cylindrical when observed from the outside. The hopper 112 may have a tapered shape, i.e., a cross-sectional area whose diameter decreases from the top to the bottom. The diameter of the top of the hopper 112 may be larger than the diameter of the bottom of the hopper 112. The top of the hopper 112 may have a larger cross-sectional area, so that the electrolyte injected from above can move entirely into the hopper 112 without overflowing. The bottom of the hopper 112 may have a relatively smaller cross-sectional area, so that the diameter of the bottom of the hopper 112 may be smaller than the diameter of the cell casing 1. This allows the hopper 112 to stably guide the flow of electrolyte toward the inside of the cell casing 1.

[0043] The lower plate 120 is provided with a mounting hole 122, and the bottom surface of the cell casing 1 may be inserted into the mounting hole 122. By inserting the cell casing 1 into the mounting hole 122, movement of the cell casing 1 may be minimized during the electrolyte injection process. The mounting hole 122 may have a shape corresponding to the axial cross section of the cell casing 1. The area of ​​the mounting hole 122 may be larger than the area of ​​the axial cross section of the cell casing 1. The shape of the mounting hole 122 may correspond to the shape of the bottom surface of the cell casing 1. The shape of the mounting hole 122 may be circular. Here, the axial cross section refers to a cross section cut perpendicular to the axis, and the axis in the axial cross section of the cell casing 1 may refer to the axis in the longitudinal direction.

[0044] The fixing member 130 can fix the positions of the upper plate 110 and the lower plate 120. The upper plate 110 and the lower plate 120 can be positioned spaced apart from each other, and both ends of the fixing member 130 are coupled to the peripheries of the upper plate 110 and the lower plate 120, respectively, thereby preventing the space between the upper plate 110 and the lower plate 120 from expanding further.

[0045] The securing member 130 may be provided in a variety of forms.

[0046] For example, the fixing member 130 may have the form of a strap having a narrow width and a long length. A locking structure may be formed at the end of the fixing member 130 so that the fixing member 130 can stably fix the upper plate 110 or the lower plate 120. More specifically, the end of the fixing member 130 may have a portion bent from the main body of the fixing member 130 toward the upper plate 110 or the lower plate 120.

[0047] After the cell case 1 is placed on the lower plate 120 and the upper plate 110 is positioned above the cell case 1, the distance between the upper plate 110 and the lower plate 120 can be adjusted. The positions of the upper plate 110 and the lower plate 120 can be fixed by connecting the ends of the fixing member 130 to the upper plate 110 and the lower plate 120.

[0048] As another example, the fixing member 130 may have a structure that allows its length to be extended by itself. Both ends of the fixing member 130 may be fixed to the upper plate 110 and the lower plate 120, and the distance between the upper plate 110 and the lower plate 120 may be adjusted by extending the length of the fixing member 130.

[0049] Meanwhile, an elastic portion 140 may be positioned below the lower plate 120. The elastic portion 140 may include an elastic body 142 having a restoring force in response to compression, and a support portion 144 supporting the lower surface of the elastic body 142. The support portion 144 is designed to have a step with the lower plate 120, so that the elastic body 142 may be positioned lower than the upper surface of the lower plate 120. The support portion 144 may support the elastic body 142 at a position lower than the upper surface of the lower plate 120. The support portion 144 may be positioned to correspond to the mounting hole 122 formed in the lower plate 120. The support portion 144 may extend downward perpendicular to the lower plate 120 from the periphery of the mounting hole 122 and then extend again radially toward the center. The support portion 144 may have an overall cylindrical shape with an open top. The elastic body 142 may be positioned corresponding to the mounting hole 122. The elastic body 142 may be positioned inside the mounting hole 122.

[0050] The elastic member 140 may serve to stably fix the cell casing 1 between the upper plate 110 and the lower plate 120. The positions of the upper plate 110 and the lower plate 120 are fixed by the fixing member 130, and the cell casing 1 may be subjected to a longitudinal compressive force, thereby fixing the position of the cell casing 1. If the distance between the upper plate 110 and the lower plate 120 is too small, the compressive force acting on the cell casing 1 may be too large, which may result in damage to the cell casing 1. Furthermore, if the distance between the upper plate 110 and the lower plate 120 is too large, sufficient compressive force may not be applied to the cell casing 1, making it difficult to stably fix the cell casing 1. Therefore, the distance between the upper plate 110 and the lower plate 120 must be adjusted according to the size of the cell casing 1. However, the size of the cell casing 1 may vary due to design and process errors, which may result in the need to reposition the upper plate 110 and the lower plate 120 each time. However, in the electrolyte injection device 100 of this embodiment, the elastic portion 140 is provided below the lower plate 120, so that cell casings 1 of different sizes can be accommodated and the cell casings 1 can be stably fixed. More specifically, the distance between the upper plate 110 and the lower plate 120, i.e., the position where the upper plate 110 and the lower plate 120 are fixed by the fixing member 130, is designed to be constant, and the compression level of the elastic body 142 is formed differently depending on the length of the cell casing 1, so that the cell casing 1 can be stably fixed to the electrolyte injection device 100.

[0051] More specifically, the cell casing 1 may be disposed on the mounting hole 122 of the lower plate 120, and the lower surface of the cell casing 1 may be positioned on the elastic portion 140. The upper plate 110 may be disposed on the upper side of the cell casing 1, and in this case, the sealing portion 116 of the upper plate 110 may correspond to the open upper surface of the cell casing 1. With the sealing portion 116 and the cell casing 1 positioned on the same axis, the positions of the upper plate 110 and the lower plate 120 are fixed by the fixing member 130, thereby fixing the cell casing 1 to the electrolyte injection device 100. In this case, the sealing portion 116 may contact the cell casing 1. More specifically, the inner surface of the sealing portion 116 may contact the periphery of the upper surface of the cell casing 1. Here, when the positions of the upper plate 110 and the lower plate 120 are fixed by the fixing member 130, the elastic body 142 of the elastic part 140 is compressed by the cell case 1, and the cell case 1 is supported upward by the restoring force of the elastic body 142, thereby allowing the cell case 1 to be positioned more stably.

[0052] 1 and 3 may be in a state where the upper plate 110 is not in close contact with the cell case 1 and the positions of the upper plate 110 and the lower plate 120 have not yet been fixed by the fixing member 130. Also, the electrolyte injection device 100 shown in FIG. 2 may be in a state where the upper plate 110 is in close contact with the cell case 1 and the positions of the upper plate 110 and the lower plate 120 have been fixed by the fixing member 130.

[0053] 1, 3, and 4, the fixing member 130 is shown as being fixed to the upper plate 110 and the lower plate 120 and as being extendable in length, but this is for convenience of illustration and may differ from the actual structure. Therefore, the fixing member 130 of this embodiment may be provided as having a fixed length and being detachable from the upper plate 110 or the lower plate 120. When both ends of the fixing member 130 are coupled to the upper plate 110 and the lower plate 120, the positions of the upper plate 110 and the lower plate 120 may be fixed. Before at least one of both ends of the fixing member 130 is fixed to the upper plate 110 or the lower plate 120, the fixing member 130 may be positioned spaced apart from the upper plate 110 or the lower plate 120.

[0054] Meanwhile, the fixing member 130 may have various structures, and therefore, the fixing member 130 may be provided in the structure shown in Figures 1, 3, and 4. More specifically, the length of the fixing member 130 may be variable, and the fixing member 130 may be provided with both ends of the fixing member 130 fixed to the upper plate 110 and the lower plate 120.

[0055] On the other hand, when injecting the electrolyte into the cell case 1, if the cell case 1 and the sealing portion 116 are not aligned on the same axis, there is a problem that the electrolyte leaks out.

[0056] 3 and 4 are diagrams showing abnormal states that may occur during electrolyte injection.

[0057] 3 and 4, during the process of injecting electrolyte into cell case 1 using electrolyte injection device 100, a first or second abnormal state may occur, causing electrolyte to leak out of cell case 1. Here, the abnormal state may refer to a state in which the sealing state between the top surface of cell case 1 and sealing portion 116 is incomplete.

[0058] More specifically, as shown in FIG. 3, the cell casing 1 may be positioned at an angle contrary to the operator's intention. That is, in a first abnormal state, the bottom surface of the cell casing 1 and the lower plate 120 may form an acute angle. In the first abnormal state, the angle between the bottom surface of the cell casing 1 and the lower plate 120 may be equal to or greater than a first value. Here, the first value may be greater than 0 and less than 90. In this way, in the first abnormal state in which the cell casing 1 is positioned at an angle, the cell casing 1 and the sealing part 116 may not be positioned on the same axis, which may cause a gap to form between the cell casing 1 and the hopper 112, resulting in leakage of the electrolyte.

[0059] 4, one side of the sealing part 116 may be damaged (A), which may cause leakage of the electrolyte. In the second abnormal state in which the sealing part 116 is damaged, even if the cell case 1 and the sealing part 116 are aligned on the same axis, the space between the cell case 1 and the hopper 112 may not be sealed, which may cause the electrolyte to leak out of the cell case 1 during the injection process.

[0060] Meanwhile, in the past, such an abnormal state could not be detected during electrolyte injection, and could only be confirmed through electrolyte outflow after electrolyte injection was completed, which caused an increase in the defective rate of battery cells.

[0061] However, the electrolyte injection device 100 of this embodiment includes the sensor unit 150, so that it can quickly determine whether or not the electrolyte has leaked or the possibility of the electrolyte leaking, and determine whether or not injection of the electrolyte is necessary.

[0062] The sensor unit 150 may be for measuring pressure applied to the lower surface of the cell casing 1. The sensor unit 150 may measure pressure acting on the cell casing 1 between the upper plate 110, the lower plate 120, and the elastic portion 140. For this purpose, the sensor unit 150 may be located above the elastic portion 140. The sensor unit 150 may be located below the cell casing 1. In other words, during the electrolyte injection process, the cell casing 1 may be disposed above the elastic portion 140 where the sensor unit 150 is located.

[0063] Conventional pressure sensors are provided one per unit area and collect pressure values ​​only for a specific position within the unit area. Therefore, the collected pressure value is assumed to be the pressure value formed over the entire unit area. Such pressure sensors are primarily used to measure the load on an object or the amount of load change over time, and in electrolyte injection devices, they are used to check the amount of electrolyte injected into a cell casing.

[0064] However, in this embodiment, since the purpose is to check the pressure formed on the underside of the cell case 1 by position and to check whether the cell case 1 is properly aligned between the upper plate 110 and the lower plate 120, a conventional pressure sensor may not be desirable to achieve the above-mentioned purpose.

[0065] In response to such requirements, the sensor unit 150 may include a sensor that measures pressure formed on a plane with high resolution. For example, the sensor unit 150 may include a surface pressure sensor. Here, the surface pressure sensor is suitable for measuring pressure on a plane, has high resolution, and may have small measurement errors even when applied to a large area. The sensor unit 150 of the present embodiment may be designed to cover a large area by using a surface pressure sensor, and may collect pressure values ​​according to each position.

[0066] In particular, as described above, the cell case 1 may have a cylindrical columnar shape, and the lower surface of the cell case 1 may have a circular shape. Here, the sensor unit 150 may be provided in a shape corresponding to the lower surface of the cell case 1.

[0067] In the first abnormal state shown in Fig. 3 and the second abnormal state shown in Fig. 4, the cell case 1 having a circular bottom surface may be tilted in one direction based on the center of the cell case 1. In this case, regardless of the direction in which the cell case 1 having a circular bottom surface is tilted, the sensor unit 150 can be located at a position corresponding to the tilted direction of the cell case 1. In other words, the sensor unit 150 can more accurately measure the pressure formed on the bottom surface of the cell case 1 regardless of the tilted direction of the cell case 1.

[0068] As shown in FIG. 2, the sensor unit 150 may be provided in a ring shape. This may be for measuring pressure formed around the periphery of the lower surface of the cell casing 1. The sensor unit 150 may also include a plurality of sub-sensors 152 arranged equiangularly. While FIG. 2 shows ten sub-sensors 152, the sensor unit 150 may include fewer or more sub-sensors 152. However, since the greater the number of sub-sensors 152 included in the sensor unit 150, the better the resolution, so it is preferable that the number of sub-sensors 152 be at least four in order for the sensor unit 150 to achieve its intended function.

[0069] In this way, when the cell case 1 has a circular bottom surface and the sensor unit 150 has a ring shape, no matter in what direction the cell case 1 having a circular bottom surface is tilted, the sensor unit 150 can be located at a position corresponding to the tilt direction of the cell case 1. In other words, even if the sub-sensor 152 is simply arranged in a ring shape along the periphery of the bottom surface of the cell case 1, the sensor unit 150 can accurately measure the pressure formed on the periphery of the bottom surface of the cell case 1 regardless of the tilt direction of the cell case 1.

[0070] Alternatively, if the cell casing 1 has a bottom surface that is shaped other than a circle, the ring-shaped sensor unit 150 may not be positioned at a position corresponding to the periphery of the bottom surface of the cell casing 1, depending on the tilt direction of the cell casing 1. That is, in this case, the sensor unit 150 may have difficulty accurately measuring the pressure formed on the periphery of the bottom surface of the cell casing 1, depending on the tilt direction of the cell casing 1. In this case, the sensor unit 150 must have multiple sub-sensors 152 arranged all over the entire bottom surface of the cell casing 1 or an area larger than the bottom surface of the cell casing 1, which can result in problems of reduced space efficiency and cost efficiency.

[0071] The sensor unit 150 includes a plurality of sub-sensors 152, thereby enabling detailed measurement of the pressure value formed on the lower surface of the cell casing 1. The sensor unit 150 can individually obtain the measured value from each sub-sensor 152.

[0072] At this time, the pressure value detected by the sensor unit 150 may be referred to as a measurement value. The measurement value may include a first measurement value and a second measurement value, and the first measurement value and the second measurement value may be values ​​collected from different sub-sensors 152. As shown in FIG. 2, if there are ten sub-sensors 152, the measurement value may include the first measurement value to the tenth measurement value.

[0073] If an abnormal state occurs in the electrolyte injection device 100, the pressure acting on the lower surface of the cell casing 1 may not be uniform. If an abnormal state occurs in the electrolyte injection device 100, the first and second measurement values ​​obtained from the sub-sensors 152 at different positions may show differences.

[0074] When a first abnormal state occurs in the electrolyte injection device 100, the pressure acting on the underside of the cell casing 1 may not be uniform. When the first abnormal state occurs, the first measurement value acquired by the sub-sensor 152 positioned in the tilted direction of the cell casing 1 may be high, and the second measurement value acquired by the sub-sensor 152 positioned in the other direction may be relatively low.

[0075] Furthermore, when the second abnormal state occurs in the electrolyte injection device 100, the pressure acting on the underside of the cell casing 1 may not be uniform. If one side of the sealing portion 116 is damaged or deformed due to deterioration, reducing the sealing force at that portion, a relatively low pressure may act on the corresponding underside of the cell casing 1. In other words, when the second abnormal state occurs, the pressure acting on the underside of the cell casing 1 may be biased.

[0076] In this way, it is possible to determine whether an abnormal state has occurred based on the measurement values ​​obtained by the sensor unit 150. It is possible to determine whether an abnormal state has occurred by comparing the calculation result of the measurement values ​​obtained by the sensor unit 150 with a predetermined condition.

[0077] Figure 5 is a diagram for explaining how the electrolyte injection device of Figure 1 determines an abnormal state. The photograph in Figure 5 shows the output of the result of detecting the pressure formed on the bottom surface of the cell case 1 through a sensor, and the pressure value measured by the sensor is displayed as a shadow and a number.

[0078] Referring to FIG. 5, the pressure acting on the underside of the cell casing 1 can be measured at different positions using the sensor unit 150, and it can be determined whether there is a deviation. In FIG. 5, T1 indicates the periphery of the underside of the cell casing 1, and the sensor unit 150 can measure the pressure value formed along T1. There are eight sub-sensors 152 corresponding to T1, and the sensor unit 150 can obtain first through eighth measurement values. More specifically, the first through eighth measurement values ​​can be 1, 1, 26, 33, 37, 59, 61, and 32, respectively. In FIG. 5, the measurement value obtained from the sub-sensor 152 located at T2 is 1, which appears significantly lower than the other measurement values. This indicates that a problem has occurred in the sealing between the sealing unit 116 and the cell casing 1. In this manner, it can be determined that a first or second abnormal state has occurred in the electrolyte injection device 100 based on the deviation in the measurement values.

[0079] Hereinafter, the results of an experiment to confirm whether or not a pressure deviation occurs depending on the position on the bottom surface of the cell case 1 when a problem occurs in the sealing state between the sealing portion 116 and the cell case 1 will be described.

[0080] In the experiments described below, the sensor unit 150 includes four sub-sensors 152, and the measurement values ​​include first to fourth measurement values ​​obtained from each sub-sensor 152. This is because the sensor unit 150 equipped with four sub-sensors 152 was used to simplify the experiment, and the number of sub-sensors 152 of the present invention is not limited depending on the content of the experiment.

[0081] In the following experiments, each measurement value was expressed as an index value relative to a reference value. Each measurement value was converted and displayed as a relative value when the normal state value was 10 or 100. Here, the normal state can be a state in which the above-mentioned abnormal state does not occur.

[0082] [Table 1]

[0083] The air pressures in Table 1 may be pressure values ​​formed inside the cell casing 1 located in the electrolyte injection device 100. Experimentally, these may be pressure values ​​formed inside the cell casing 1 when air is injected into the cell casing 1 through the hopper 112 on the electrolyte injection device 100.

[0084] In Table 1, the air pressure value may be displayed as a relative value to a reference value. Here, the reference value may be the pressure value inside the cell case 1 intended by the operator or may be the pressure value normally expected inside the cell case 1.

[0085] In Table 1, the reference value of air pressure was set to 10. For example, if the pressure value inside cell case 1 is expected to be 8 psi under normal conditions and the actual measured value is 4 psi, the experimental result may be listed as 5 in Table 1.

[0086] Referring to the above description, if the air pressure value in the experiment of Table 1 is less than 10, an abnormal state may have occurred in the electrolyte injection device 100. More specifically, in cases 2 and 4 of Table 1, where the air pressure value was measured to be relatively low, it was confirmed that the cell case 1 was positioned in an inclined state.

[0087] The total load value (kgf) may be the sum of the measurement values ​​detected by the sub-sensors 152 included in the sensor unit 150. In this experiment, there were four sub-sensors 152, and the total load value may be the sum of the first to fourth measurement values. In addition, the maximum load value (kgf) and the minimum load value (kgf) may be the maximum and minimum values ​​of the first to fourth measurement values.

[0088] In addition, the total load value, maximum load value, minimum load value, and average value of the total load may be displayed as relative values ​​in Table 1. Here, the reference value may correspond to the compressive force formed on the elastic body 142 in a normal state.

[0089] In Table 1, the reference value of the total load is set to 100. For example, if the compressive force formed in the elastic body 142 or the pressure value obtained from the sensor unit 150 due to the compressive force is expected to be 70 kgf under normal conditions, and the total pressure value obtained from the sub-sensor 152 is actually 60 kgf, this can be expressed as 85.7 in the table below.

[0090] Comparing the total load values ​​for each case, the values ​​for case 2 and case 4 were higher than the values ​​for case 1 and case 3, where the alignment state was flat. This may be because when the cell casing 1 is positioned flat, the cell casing 1 properly applies a compressive force to the elastic part 140. Therefore, the alignment state of the cell casing 1 can be estimated by summing up the measurement values ​​obtained from the sensor unit 150. Whether or not an abnormal state has occurred can be determined by summing up the measurement values ​​obtained from the sensor unit 150.

[0091] Furthermore, when comparing the relative standard deviation (%) of each case, the values ​​for case 2 and case 4 were lower than the values ​​for case 1 and case 3, where the alignment state was flat. This may mean that when the cell casing 1 is positioned flat, the deviation of the pressure value formed on the bottom surface of the cell casing 1 decreases. Therefore, the alignment state of the cell casing 1 can be inferred from the relative standard deviation of the measurement values ​​acquired from the sensor unit 150. Whether or not an abnormal state has occurred can be determined from the relative standard deviation of the measurement values ​​acquired from the sensor unit 150.

[0092] As such, when an abnormal state occurs, a deviation may occur between the measurement values ​​acquired from the sensor unit 150. The electrolyte injection device 100 of the present embodiment can check the distribution of pressure formed on the bottom surface of the cell casing 1 through the measurement values ​​acquired by the sensor unit 150. Based on this, the electrolyte injection device 100 can determine whether an abnormal state has occurred.

[0093] Although not shown, the electrolyte solution injection device 100 of this embodiment may include a control unit that controls the overall operation of the electrolyte solution injection device 100.

[0094] The control unit may receive measurement values ​​collected from the sensor unit 150. The control unit may individually receive measurement values ​​obtained from each sub-sensor 152. The control unit may also calculate the measurement values ​​obtained by each sub-sensor 152 to calculate the sum, average, standard deviation, etc. among the measurement values. The control unit may control an output unit included in the electrolyte injection device 100 to display the processed data, i.e., the pressure value or a calculated value thereof, or may transmit a request to an output device connected to the electrolyte injection device 100 to operate. In this case, the electrolyte injection device 100 may include a communication unit for communicating with an external device.

[0095] The control unit can determine whether an abnormal state has occurred in the electrolyte solution injection device 100 based on the pressure value collected from the sensor unit 150. The control unit can control the electrolyte solution injection device 100 to inject the electrolyte solution based on the pressure value collected from the sensor unit 150. The control unit can determine whether the calculation result of the collected data corresponds to a predetermined condition. If the calculation result corresponds to the predetermined condition, the control unit can control the electrolyte solution injection device 100 to inject the electrolyte solution.

[0096] Here, there may be multiple predetermined conditions, and the control unit can determine whether or not to inject the electrolyte solution by determining whether each condition is met. For example, the control unit can control the electrolyte solution injection device 100 to inject the electrolyte solution when the first condition and the second condition are met. Furthermore, the control unit can control the electrolyte solution injection device 100 not to inject the electrolyte solution when either the first condition or the second condition is not met.

[0097] However, as described above, data processing and manipulation does not necessarily have to be performed by the control unit of the electrolyte injection device 100, but according to an embodiment, the sensor unit 150 may include a separate control unit, and the above-mentioned data may be processed by the control unit included in the sensor unit 150.

[0098] Meanwhile, the predetermined conditions can be set in various ways.

[0099] The determination of the predetermined conditions described below is explained to be performed by the control unit, and here the control unit may be attached to the electrolyte injection device 100 or may be provided independently in the sensor unit 150.

[0100] As an example of the predetermined condition, the control unit may consider the sum of the values ​​collected from the sub-sensors 152. Assuming that the sensor unit 150 includes three sub-sensors 152, the control unit may compare the sum of the first to third measurement values ​​with a first reference value. If the difference between the sum of the first to third measurement values ​​and the first reference value is within a predetermined range, the control unit may determine that the first condition is met.

[0101] Here, the first reference value may be a predetermined value. The first reference value may be a value set through experiments as shown in Table 1 above, or may be a value determined through calculation.

[0102] The first reference value may be related to a compressive force formed on the elastic body 142. The first reference value may be related to a pressure value that is expected to be applied to the elastic body 142 by the cell case 1 when the electrolyte solution injection device 100 is designed. The first reference value may be the pressure value itself that is expected to be applied to the elastic body 142 in a normal state. Alternatively, the first reference value may be a total pressure value that is expected to be collected by the sensor unit 150 in a normal state.

[0103] Alternatively, the first reference value may be a pressure value formed on the bottom surface of the cell casing 1 when no abnormal state occurs, as shown in Table 1. More specifically, the sum of the measured values ​​formed on the bottom surface of the cell casing 1 measured by the sensor unit 150 when an abnormal state occurs and when no abnormal state occurs may be calculated. This process may be repeated through experiments, and the first reference value and the predetermined range may be determined accordingly.

[0104] As another example of the predetermined condition, the control unit may consider the degree of dispersion of the values ​​collected from the sub-sensor 152. Here, the degree of dispersion may be calculated using a relative standard deviation. Alternatively, the degree of dispersion may be calculated using another calculation formula other than the relative standard deviation that can represent the degree of dispersion of multiple values. The control unit may compare the relative standard deviation of the first to third measurement values ​​with a second reference value. If the relative standard deviation of the first to third measurement values ​​is smaller than the second reference value, the control unit may determine that the second condition is satisfied.

[0105] Here, the second reference value may be a predetermined value. The second reference value may be a value set through experiments as shown in Table 1 above, or may be a value determined through calculation.

[0106] The second reference value may be related to the outflow air pressure. The outflow air pressure may refer to the magnitude of the air pressure that flows out between the cell casing 1 and the sealing unit 116 when air is injected into the cell casing 1 through the hopper 112 in the electrolyte injection device 100. More specifically, the outflow air pressure may be calculated as the difference between the air pressure (p1) expected to be formed inside the cell casing 1 and the air pressure (p2) actually formed inside the cell casing 1, and may be calculated as "outflow air pressure = p1 - p2." A higher outflow air pressure value may indicate a problem with the sealing between the sealing unit 116 and the cell casing 1.

[0107] The second reference value may be determined experimentally. The outflow air pressure when an abnormal state occurs may be measured through an experiment, and the relative standard deviation of the measured value may be calculated. More specifically, if the outflow air pressure value is equal to or greater than a predetermined value, it may be determined that an abnormal state has occurred in the electrolyte injection device 100. If the outflow air pressure value is equal to or greater than a predetermined value, the relative standard deviation of the pressure values ​​formed on the bottom surface of the cell casing 1 may be calculated as shown in Table 1 above, and the second reference value may be determined based on this. In determining the second reference value, the relative standard deviation of the pressure values ​​on the bottom surface of the cell casing 1 when no abnormal state occurs may be taken into consideration. In this way, the occurrence of an abnormal state may be determined based on the second reference value determined through an experiment.

[0108] An electrolyte injection method based on the above description will now be described. The electrolyte injection method described below may be performed by the above-described electrolyte injection device 100. Therefore, the above content may be applied to the following description, and the same description will be omitted to avoid duplication.

[0109] 6 is a flowchart showing a method for injecting an electrolyte solution according to an embodiment of the present invention, and FIG. 7 is a flowchart showing a part of the method for injecting an electrolyte solution according to FIG.

[0110] Referring to FIG. 6, the electrolyte injection method (S100) according to this embodiment may include a step (S110) of placing the cell case 1 in the mounting hole 122 of the lower plate 120, a step (S120) of fixing the position of the upper plate 110 located above the cell case 1 or the lower plate 120 on which the cell case 1 is placed, a step (S130) of determining whether an abnormal state has occurred based on a pressure value collected by the sensor unit 150, and if it is determined that an abnormal state has occurred, a step (S140) of re-fixing the position of the upper plate 110 or the lower plate 120, a step (S150) of checking the state of the sealing unit 116 if it is determined that an abnormal state has occurred, and if it is determined that no abnormal state has occurred, a step (S160) of injecting electrolyte into the inside of the cell case 1.

[0111] Each stage is described in more detail below.

[0112] The cell casing 1 may be placed in the mounting hole 122 of the lower plate 120 (S110). An elastic part 140 may be positioned on the underside of the lower plate 120 at a position corresponding to the mounting hole 122. The cell casing 1 may be inserted into the mounting hole 122 and positioned on the elastic body 142 of the elastic part 140.

[0113] The position of the upper plate 110 located above the cell casing 1 or the lower plate 120 on which the cell casing 1 is placed may be fixed (S120). This restricts movement of the cell casing 1, and the cell casing 1 may be fixed inside the electrolyte injection device 100. More specifically, the positions of the upper plate 110 and the lower plate 120 may be fixed by a fixing member 130. The upper plate 110 and the lower plate 120 are fixed in a state in which they press the cell casing 1, thereby compressing the elastic body 142 located on the underside of the cell casing 1. The restoring force of the elastic body 142 presses the upper plate 110, the lower plate 120, and the cell casing 1 against each other, so that the cell casing 1 may be stably fixed between the upper plate 110 and the lower plate 120. At this time, the cell casing 1 may be positioned coaxially with the sealing portion 116.

[0114] Meanwhile, when the cell casing 1 is fixed on the upper plate 110 and the lower plate 120, electrolyte may be injected into the cell casing 1 through the hopper 112 of the upper plate 110. At this time, a sealing unit 116 may be positioned between the cell casing 1 and the hopper 112. The sealing unit 116 seals the space between the cell casing 1 and the hopper 112, thereby preventing leakage of the electrolyte when the electrolyte is injected. However, as described above, if the cell casing 1 is not positioned coaxially with the sealing unit 116 or if the sealing unit 116 is damaged, the electrolyte may leak out of the cell casing 1.

[0115] However, in this embodiment, whether or not an abnormal state has occurred may be determined based on pressure values ​​collected by the sensor unit 150 (S130). The sensor unit 150 may measure the pressure formed on the bottom surface of the cell casing 1. The sensor unit 150 may include a plurality of sub-sensors 152, thereby obtaining pressure values ​​corresponding to each position. The electrolyte injection device 100 may determine whether or not an abnormal state has occurred based on the obtained measurement values. The abnormal state may include a first abnormal state and a second abnormal state, and for more information, see the description of FIGS. 3 and 4. Here, the step of determining whether or not an abnormal state has occurred (S130) may be performed before injecting the electrolyte.

[0116] The measured value obtained from the sensor unit 150 may be processed using a pre-stored calculation formula. If the processed calculated value does not satisfy a predetermined condition, the control unit may determine that an abnormal state has occurred in the electrolyte solution injection device 100. The calculation of the measured value and the determination of whether the predetermined condition is satisfied may be performed by the control unit, and the control unit may be included in the sensor unit 150 or the electrolyte solution injection device 100. Furthermore, the control unit oversees the operation of the electrolyte solution injection device 100, and although not specifically described, it may be understood that the calculation of the determination result and the control of the operation of the components in this embodiment are performed by the control unit.

[0117] Meanwhile, depending on the determination result of step S130, the electrolyte injection method S100 can proceed to step S140, step S150, or step S160.

[0118] For example, if it is determined that no abnormal state has occurred, the electrolyte injection device 100 may inject the electrolyte into the cell case 1 (S160). The electrolyte may be injected through the hopper 112 of the upper plate 110.

[0119] As another example, if it is determined that an abnormal condition has occurred, the electrolyte injection device 100 may re-fix the positions of the upper plate 110 and the lower plate 120 (S140) or check the state of the sealing portion 116 (S150), which may be to eliminate the cause of the first or second abnormal condition described above.

[0120] Here, after performing step S140 or step S150, step S130 may be re-evaluated to determine whether the cause of the abnormal state has been eliminated. Depending on the result of the re-evaluation of step S130, the electrolyte injection method S100 may proceed to step S140, step S150, or step S160.

[0121] If it is determined that an abnormal condition has occurred, the electrolyte injection device 100 may re-fix the positions of the upper plate 110 and the lower plate 120 (S140). This may be to remove the cause of the first abnormal condition. This may be to correct misalignment between the sealing portion 116 and the cell casing 1. This may be to position the sealing portion 116 and the cell casing 1 on the same axis. Here, since step (S140) is the same or similar in content to step (S120), it may also be explained that step (S120) is performed again depending on the determination result of step (S130).

[0122] If it is determined that an abnormal state has occurred, the positional fixation of the upper plate 110 and the lower plate 120 by the fixing members 130 may be released. This allows the distance between the upper plate 110 and the lower plate 120 to increase. This allows the upper plate 110 to move upward, or the lower plate 120 to move downward. By releasing the positional fixation between the upper plate 110 and the lower plate 120, the cell casing 1 may be separated from the upper plate 110, and the top surface of the cell casing 1 may be separated from the sealing portion 116 of the upper plate 110.

[0123] Thereafter, the positions of the upper plate 110 and the lower plate 120 may be fixed again by the fixing member 130. Thus, the cell casing 1 may be fixed again in the electrolyte injection device 100. At this time, the sealing portion 116 and the upper surface of the cell casing 1 may be in close contact with each other.

[0124] When the positions of the upper plate 110 and the lower plate 120 are fixed by the fixing member 130 and the cell case 1 is attached to the electrolyte injection device 100, the sensor unit 150 can measure the pressure formed on the lower surface of the cell case 1. Whether or not an abnormal state has occurred can be determined again based on the pressure value collected by the sensor unit 150. In this manner, after step S140 is performed, step S130 can be performed again.

[0125] Steps S140 and S130 may be repeated. In other words, after the positions of the upper plate 110 and the lower plate 120 are re-fixed, it is again determined whether an abnormal state has occurred based on the value acquired by the sensor unit 150. If it is determined that an abnormal state has occurred, the positions of the upper plate 110 and the lower plate 120 may be re-fixed.

[0126] The steps S140 and S130 may be repeated a predetermined number of times (SN). Here, the predetermined number of times (SN) may be a pre-calculated value or a pre-entered value. For example, the predetermined number of times (SN) may be three times. If it is determined that an abnormal state has occurred after steps S140 and S130 have been repeated three times, step S150 may be performed.

[0127] For this purpose, the electrolyte injection device 100, more specifically, the control unit, can count the number of repetitions (RN), which may be the number of repetitions of step S140.

[0128] For example, the initial value of the number of repetitions (RN) may be 0, and may be increased by 1 by repeating step (S140). Therefore, if the preset number of repetitions (SN) is 1, step (S130) may be performed after step (S140) is performed, and step (S150) or step (S160) may be performed depending on the determination result of step (S130).

[0129] Therefore, the electrolyte injection method (S100) of this embodiment may further include a step (S132) of comparing the number of repetitions (RN) with a preset number of repetitions (SN) if it is determined through step (S130) that an abnormal state has occurred. Here, if the number of repetitions (RN) is less than the preset number of repetitions (SN), step (S140) may be performed. If the number of repetitions (RN) is equal to or greater than the preset number of repetitions (SN), step (S150) may be performed.

[0130] When it is determined that an abnormal condition has occurred, the electrolyte injection device 100 may check the condition of the sealing unit 116 (S150). This may be to eliminate the cause of the second abnormal condition. If the sealing unit 116 is damaged, worn, or deformed, the seal between the sealing unit 116 and the cell casing 1 may not be sealed, which may cause the pressure formed on the underside of the cell casing 1 to be distorted. If damage, wear, or deformation of the sealing unit 116 is confirmed, the sealing unit 116 may be replaced. At this time, step S160 may be performed, and the number of repetitions (RN) may be reset to the initial value of 0.

[0131] After it is confirmed that there is no abnormality in the sealing unit 116 or after the replacement of the sealing unit 116 is completed, the cell case 1 may be fixed in the electrolyte injection device 100 by the upper plate 110, the lower plate 120, and the elastic member 140. When the positions of the upper plate 110 and the lower plate 120 are fixed by the fixing member 130 and the cell case 1 is attached to the electrolyte injection device 100, the sensor unit 150 may measure the pressure formed on the lower surface of the cell case 1. Whether or not an abnormal state has occurred may be determined again based on the pressure value collected by the sensor unit 150. In this manner, after step S150 is performed, step S130 may be performed again.

[0132] Here, since the inspection or replacement of the sealing portion 116 can be performed while the upper plate 110 and the cell case 1 are separated, it can also be explained that after step S150 is performed, step S120 or step S110 is performed again.

[0133] 7, whether or not an abnormal state occurs in the electrolyte injection device 100 may be determined based on predetermined conditions. Here, the predetermined conditions may include a first condition and a second condition.

[0134] As shown in FIG. 7, the method for determining whether an abnormal state has occurred in the electrolyte injection device 100 (S200) includes a step of determining whether the calculation result of the measurement value obtained from the sensor unit 150 satisfies a first condition (S210), a step of determining whether the calculation result of the measurement value obtained from the sensor unit 150 satisfies a second condition (S220), a step of determining whether an abnormal state has occurred in the electrolyte injection device 100 if the first condition or the second condition is not met (S230), and a step of determining whether an abnormal state has not occurred in the electrolyte injection device 100 if the first condition and the second condition are met (S240).

[0135] The control unit may determine whether the calculation result of the acquired measurement values ​​satisfies a first condition (S210). The first condition may relate to whether a difference between the sum of the measurement values ​​and a first reference value is within a predetermined range. The control unit may determine that the first condition is satisfied if the difference between the sum of the measurement values ​​and the first reference value is within the predetermined range. Here, the first reference value may be a value derived through experiment or theory.

[0136] The control unit may determine whether the calculation result of the acquired measurement values ​​satisfies a second condition (S220). The second condition may relate to whether the relative standard deviation value of the measurement values ​​is smaller than a second reference value. The control unit may determine that the second condition is satisfied if the relative standard deviation of the measurement values ​​is smaller than the second reference value. Here, the second reference value may be a value derived through experiments.

[0137] If the first or second condition is not met, the control unit may determine that an abnormal state has occurred in the electrolyte injection device 100 (S230). If it is determined that an abnormal state has occurred in the electrolyte injection device 100, step S140 or step S150 may be performed as illustrated in FIG. 6. Here, step S132 may be performed before step S140 or step S150 is performed, and step S140 or step S150 may be performed depending on the determination result of step S132.

[0138] If the first and second conditions are satisfied, the control unit may determine (S240) that an abnormal state has not occurred in the electrolyte injection device 100. If it is determined that an abnormal state has not occurred in the electrolyte injection device 100, step (S160) may be performed as described in FIG.

[0139] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the claims also fall within the scope of the present invention. [Explanation of symbols]

[0140] 1: Cell case 100: Electrolyte injection device 110: Upper plate 112: Hopper 114: Electrolyte inlet 116: Sealing part 120: Lower plate 122: Mounting hole 130: Fixing member 140: Elastic part 150: Sensor unit

Claims

1. An electrolyte injection device for injecting an electrolyte into a cell case, an upper plate having a hopper built therein for pouring electrolyte into the cell case from above the cell case; a lower plate having a mounting hole on which the lower surface of the cell case is placed; an elastic portion disposed on the lower side of the lower plate at a position corresponding to the mounting hole, the elastic portion being compressed in response to pressure applied to the lower surface of the cell casing; An electrolyte injection device, wherein a sensor unit for measuring pressure applied to the lower surface of the cell case is disposed on the upper part of the elastic part.

2. The electrolyte injection device according to claim 1 , further comprising a sealing portion that seals a gap between an upper surface of the cell case and a lower surface of the hopper.

3. 3. The electrolyte injection device according to claim 1, wherein the sensor unit is disposed so as to correspond to a peripheral edge of the lower surface of the cell case.

4. The electrolyte injection device according to claim 1 , wherein the sensor unit includes a surface pressure sensor.

5. The measurement value by the sensor unit includes a pressure value corresponding to each position, 3. The electrolyte injection device according to claim 1, wherein the occurrence of an abnormal state is determined based on the measured value.

6. The electrolyte injection device of claim 5, wherein the abnormal states include a first abnormal state in which the lower surface of the cell case and the lower plate form an acute angle, and a second abnormal state in which the sealing state between the upper surface of the cell case and the upper plate is incomplete.

7. 6. The electrolyte injection device according to claim 5, wherein the occurrence of the abnormal state is determined based on whether or not a calculation result of the measurement value satisfies a predetermined condition.

8. 8. The electrolyte injection device according to claim 7, wherein the predetermined conditions include a first condition and a second condition.

9. the sensor unit includes a plurality of sub-sensors, the predetermined condition includes a first condition, 8. The electrolyte injection device according to claim 7, wherein the first condition is determined to be satisfied when a difference between a sum of the measurement values ​​obtained from the plurality of sub-sensors and a first reference value is within a predetermined range.

10. the sensor unit includes a plurality of sub-sensors, the predetermined condition includes a second condition, 8. The electrolyte injection device according to claim 7, wherein the second condition is determined to be satisfied when a relative standard deviation of the measurement values ​​obtained from the plurality of sub-sensors is smaller than a second reference value.

11. 2. An electrolyte injection method using the electrolyte injection device according to claim 1, placing the cell case in the mounting hole of the lower plate; fixing the positions of an upper plate located above the cell case and the lower plate on which the cell case is placed; a step of measuring a pressure formed on a lower surface of the cell case by a sensor unit to obtain a measured value and determining whether an abnormal state has occurred based on the measured value; and The electrolyte injection method includes injecting electrolyte into the cell case when it is determined that the abnormal state does not occur.

12. The method of claim 11 , further comprising the step of re-fixing the positions of the upper plate and the lower plate when it is determined that the abnormal state has occurred.

13. After the step of re-fixing the positions of the upper plate and the lower plate, The method of claim 12 , wherein the step of determining whether an abnormal state occurs is performed again.

14. After the step of determining whether or not an abnormal state has occurred, 14. The method of claim 12 or 13, further comprising the step of comparing the number of repetitions with a preset number of times when it is determined that the abnormal state has occurred, and the number of repetitions is increased by 1 by performing the re-fixing step.

15. The method of claim 14 , wherein the re-fixing step is performed when the number of repetitions is less than the preset number.

16. 15. The method of claim 14, further comprising: checking a state of a sealing portion located under the upper plate when the number of repetitions is equal to or greater than the predetermined number.

17. The electrolyte injection method according to claim 12 or 13, wherein the step of determining whether or not an abnormal state has occurred includes the step of determining whether or not a calculation result of the measurement value satisfies a first condition.

18. The method of claim 17 , wherein the step of determining whether an abnormal state occurs further comprises determining whether a calculation result of the measurement value satisfies a second condition.

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