Electrolyte injection device and electrolyte injection method using the same

Abstract

The electrolyte injection device according to one embodiment of the present invention injects an electrolyte into a battery cartridge, and comprises: an upper plate having therein a hopper for injecting the electrolyte into the battery cartridge from above the battery cartridge; a lower plate having a mounting hole in which a lower surface of the battery case is seated; and an elastic portion located at a position lower than the lower plate and corresponding to the mounting hole, and compressed by a pressure applied to a lower surface of the battery cartridge, in which a sensor unit for measuring the pressure applied to the lower surface of the battery cartridge is positioned on an upper portion of the elastic portion.

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0002] This application is based on and claims the priority of 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, with the Korean Intellectual Property Office, the entire disclosures of which are incorporated herein by reference in their entirety.

[0003] The present disclosure 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 battery case during the manufacturing process of a battery cell, and an electrolyte injection method using the same. Background Art

[0004] As secondary batteries have received considerable attention as an energy source for power drive devices such as electric bicycles, electric vehicles, and hybrid electric vehicles, and as an energy source for mobile devices such as mobile phones, digital cameras, and laptop computers, the demand for secondary batteries has increased rapidly.

[0005] Based on the shape of the battery case, secondary batteries can be classified into cylindrical batteries in which the electrode assembly is installed in a cylindrical metal container, prismatic batteries in which the electrode assembly is installed in a prismatic metal container, or pouch - type batteries in which the electrode assembly is installed in a pouch - shaped case formed of an aluminum laminate.

[0006] In addition, electrode assemblies can generally be classified into: a gel - roll type (wound type) electrode assembly having a structure in which a long - sheet - type positive electrode and a negative electrode are wound together with a separator interposed therebetween; a stacked type (laminated type) electrode assembly in which a plurality of positive electrodes and negative electrodes cut in a predetermined size unit are sequentially stacked with a separator interposed therebetween; and a stacked / folded type electrode assembly in which a stacked type unit cell is wound with a long separator.

[0007] During the manufacturing process of a battery cell, the electrode assembly is sealed in a predetermined case together with an electrolyte. In the case of a cylindrical battery, a gel - roll type electrode assembly is inserted into a metal can, and an electrolyte is injected. If the metal can is tilted or the sealing member coupled to the metal can is damaged, the injected electrolyte may leak. However, during the process, there is no way to confirm the tilt of the metal can and the damage to the sealing member, which causes the problem of continuously producing defective products. Summary of the Invention

[0008] Technical problem

[0009] Therefore, the present disclosure has been designed to solve the above problems, and thus, its object is to prevent electrolyte leakage by pre-detecting abnormalities when injecting electrolyte into the battery case of a battery cell.

[0010] Technical solution

[0011] An electrolyte injection device according to an embodiment of the present disclosure is an electrolyte injection device for injecting electrolyte into a battery case, the device including: an upper plate having a built-in hopper for injecting electrolyte into the battery case at an upper side of the battery case; a lower plate having a mounting hole through which a lower surface of the battery case is disposed; and an elastic part located at a position corresponding to the mounting hole on a lower side of the lower plate and compressed according to a pressure applied to the lower surface of the battery case, wherein a sensor unit for measuring the pressure applied to the lower surface of the battery case is positioned on an upper part of the elastic part.

[0012] The electrolyte injection device may further include a sealing part that hermetically seals a gap between an upper surface of the battery case and a lower surface of the hopper.

[0013] The sensor unit may be positioned to correspond to an edge of the lower surface of the battery case.

[0014] The sensor unit may include a surface pressure sensor.

[0015] A measured value of the sensor unit includes pressure values according to each position, and it may be determined whether an abnormal state has occurred based on the measured value.

[0016] The abnormal state may include a first abnormal state and a second abnormal state. In the first abnormal state, an acute angle is formed between the lower surface of the battery case and the lower plate. In the second abnormal state, the sealing state between the upper surface of the battery case and the upper plate is incomplete.

[0017] It may be determined whether an abnormal state has occurred based on whether a calculation result of the measured value satisfies a predetermined condition.

[0018] The predetermined condition may include a first condition and a second condition.

[0019] The sensor unit includes a plurality of sub-sensors, the predetermined condition includes a first condition, and it may be determined that the first condition is satisfied when a difference between a sum of measured values obtained from the plurality of sub-sensors and a first reference value is within a predetermined range.

[0020] The sensor unit includes a plurality of sub-sensors, the predetermined condition includes a second condition, and in the case where the relative standard deviation of the measurement values obtained from the plurality of sub-sensors is less than a second reference value, it can be determined that the second condition is satisfied.

[0021] According to another embodiment of the present disclosure, an electrolyte injection method uses the above-mentioned electrolyte injection device, and the electrolyte injection method includes: a step of placing a battery case in a mounting hole of a lower plate, a step of fixing the positions of an upper plate located on the upper side of the battery case and the lower plate on which the battery case is placed, a step of measuring a pressure formed on the lower surface of the battery case through a sensor unit to obtain a measurement value and determining whether an abnormal state has occurred based on the measurement value, and a step of injecting an electrolyte into the interior of the battery case in the case where it is determined that no abnormal state has occurred.

[0022] In the case where it is determined that an abnormal state has occurred, the electrolyte injection method may include a step of re-fixing the positions of the upper plate and the lower plate.

[0023] After the step of re-fixing the positions of the upper plate and the lower plate, the step of determining whether an abnormal state has occurred may be performed again.

[0024] After the step of determining whether an abnormal state has occurred, the method further includes a step of comparing the number of repetitions with a preset number in the case where it is determined that an abnormal state has occurred, wherein the number of repetitions can be increased by 1 by performing the re-fixing step.

[0025] In the case where the number of repetitions is less than the preset number, the re-fixing step may be performed.

[0026] In the case where the number of repetitions is equal to or greater than the preset number of repetitions, the step of checking the state of a sealing portion located at a lower portion of the upper plate may be performed.

[0027] The step of determining whether an abnormal state has occurred may include a step of determining whether the calculation result of the measurement value satisfies a first condition.

[0028] The step of determining whether an abnormal state has occurred may further include a step of determining whether the calculation result of the measurement value satisfies a second condition.

[0029] Advantageous Effects

[0030] According to one aspect of the present disclosure, during the manufacturing process of a cylindrical battery, an abnormality during electrolyte injection can be detected in advance, thereby preventing electrolyte leakage and minimizing the defect rate.

[0031] In addition, the present disclosure may have various other effects, and these effects will be described in each embodiment, or the description of effects that can be easily inferred by those skilled in the art will be omitted. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a side view of an electrolyte injection device according to an embodiment of the present disclosure.

[0033] Figure 2 is a diagram showing a sensor unit mounted on the electrolyte injection device according to Figure 1 the electrolyte injection device.

[0034] Figure 3 and Figure 4 are diagrams showing abnormal states that may occur during electrolyte injection.

[0035] Figure 5 is a diagram for explaining how the electrolyte injection device according to Figure 1 determines an abnormal state.

[0036] Figure 6 is a flowchart showing an electrolyte injection method according to an embodiment of the present disclosure.

[0037] Figure 7 is a flowchart embodying a part of the electrolyte injection method according to Figure 6 the electrolyte injection method. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but should be construed as meanings and concepts consistent with the technical aspects of the present disclosure on the basis that the inventor can appropriately define the concept of the terms so as to best explain the present invention. Therefore, the embodiments described in the specification and the configurations shown in the drawings are only the most exemplary embodiments of the present disclosure and do not fully cover the spirit of the present disclosure. Therefore, it should be understood that various equivalents and modifications alternative to these configurations may exist when this application is filed.

[0039] In the drawings, for convenience of description and clarity, the dimensions of each component or a specific part constituting the component are enlarged, omitted, or schematically shown. Therefore, the dimensions of each element do not exactly reflect the actual dimensions. In addition, detailed descriptions related to well-known functions or configurations will be omitted so as not to unnecessarily obscure the subject matter of the present disclosure.

[0040] In addition, it will be understood that when an element such as a layer, film, region, or plate is referred to as being "on" or "above" another element, the element can be directly on the other element or there can also be an intervening element. Conversely, when an element is referred to as being "directly on" another element, this means that there are no other intervening elements. Further, the terms "on" or "above" refer to being disposed on or below a reference portion and do not necessarily mean being disposed on the upper end portion of the reference portion in the opposite direction of gravity. At the same time, similar to the case where it is described as being located "on" or "above" another portion, the case where it is described as being located "under" or "below" another portion will also be understood with reference to the above.

[0041] In addition, throughout the description, when a part is referred to as "including" or "containing" a certain component, unless otherwise stated, it means that the part may also include other components without excluding other components.

[0042] In addition, throughout the description, when it is referred to as a "plane", this means observing the target part from the upper side, and when it is referred to as a "cross-section", this means observing the target part from the side of the cross-section cut vertically.

[0043] Now, an electrolyte injection device according to an embodiment of the present disclosure will be described.

[0044] The electrolyte injection device according to an embodiment of the present disclosure is used to inject an electrolyte into a battery case after inserting an electrode assembly into the battery case during the manufacturing process of a battery cell.

[0045] Figure 1 is a side view of an electrolyte injection device according to an embodiment of the present disclosure. Figure 2 shows the installation on the basis of Figure 1 a schematic diagram of a sensor unit on the electrolyte injection device.

[0046] Referring to Figure 1 FIG. [FIG. NUMBER NOT PROVIDED IN THE ORIGINAL], the electrolyte injection device 100 of the present embodiment may include: an upper plate 110 located on the upper side of the battery case 1; a lower plate 120 corresponding to the lower surface of the battery case 1; a fixing member 130 that fixes the positions of the upper plate 110 and the lower plate 120 to minimize the movement of the battery case 1; an elastic part 140 that supports the lower surface of the battery case 1 at the lower part of the lower plate 120; and a sensor unit 150 located on the upper surface of the elastic part 140 and detecting a pressure value formed on the lower surface of the battery case 1.

[0047] Meanwhile, the electrolyte injection device 100 of the present embodiment can be used for manufacturing cylindrical batteries. Therefore, the battery case 1 described in the present embodiment can have a cylindrical shape. The battery case 1 can include a circular lower surface and a circumferential surface extending upward from the edge of the lower surface. Here, the upper surface of the battery case 1 can be in an open state.

[0048] The upper plate 110 can include a hopper 112 that guides the flow of the electrolyte injected into the battery case 1. The hopper 112 can have a shape that penetrates the upper plate 110. An electrolyte injection port 114 can be positioned at the upper portion of the hopper 112, and a sealing portion 116 can be positioned at the lower portion of the hopper 112.

[0049] The sealing portion 116 can hermetically seal the gap between the hopper 112 and the upper portion of the battery case 1, thereby preventing leakage of the electrolyte that moves from the hopper 112 to the battery case 1. The sealing portion 116 can be located at the lower portion of the upper plate 110. The sealing portion 116 can have an annular shape, where the upper portion of the sealing portion 116 can correspond to the edge of the hopper 112, and the lower portion of the sealing portion 116 can correspond to the edge of the upper surface of the battery case 1. The sealing portion 116 can be made of an elastic material so as to easily come into close contact with the battery case 1.

[0050] As Figure 1 shown, the sealing portion 116 can have a conical shape in which its top portion has been completely removed. The sealing portion 116 can have a shape in which the diameter of its cross-sectional area increases as it goes from the upper portion to the lower portion. The diameter value of the upper portion of the sealing portion 116 can be greater than the diameter value of the lower portion of the hopper 112. The diameter value of the lower portion of the sealing portion 116 can be greater than the diameter value of the upper portion of the battery case 1. Thus, the sealing portion 116 can stably seal the gap between the hopper 112 and the battery case 1.

[0051] Although not specifically shown in the figure, the hopper 112 may have an inverted conical shape with its top portion removed. This shape may be formed inside the hopper 112 such that when viewed from the outside, the hopper 112 may appear to have a cylindrical shape. The hopper 112 may have a tapered shape, i.e., the diameter value of the cross-sectional area decreases as it goes from the upper portion to the lower portion. The diameter value of the upper portion of the hopper 112 may be greater than the diameter value of the lower portion of the hopper 112. The upper portion of the hopper 112 may have a large cross-sectional area value, whereby the electrolyte injected from the upper portion does not leak but can move completely into the hopper 112. Additionally, the lower portion of the hopper 112 may have a relatively small cross-sectional area, and the diameter value of the lower portion of the hopper 112 may be smaller than the diameter value of the battery case 1. Thus, the hopper 112 can stably guide the flow of the electrolyte toward the inside of the battery case 1.

[0052] The lower plate 120 is provided with mounting holes 122, and the lower surface of the battery case 1 may be inserted into the mounting holes 122. The battery case 1 may be inserted into the mounting holes 122, whereby the flow of the battery case 1 during the electrolyte injection process is minimized. The mounting holes 122 may have a shape corresponding to the axial cross-section of the battery case 1. The area of the mounting holes 122 may be greater than the area of the axial cross-section of the battery case 1. The shape of the mounting holes 122 may correspond to the shape of the lower surface of the battery case 1. The shape of the mounting holes 122 may be circular. Here, the axial cross-section may refer to the cross-section cut perpendicular to the axis, and the axis in the axial cross-section of the battery case 1 may refer to the axis in the longitudinal direction.

[0053] The fixing member 130 may fix the positions of the upper plate 110 and the lower plate 120. The upper plate 110 and the lower plate 120 may be positioned separately from each other, and the two end portions of the fixing member 130 are respectively connected to the edges of the upper plate 110 and the lower plate 120 such that the gap between the upper plate 110 and the lower plate 120 can be prevented from widening further.

[0054] The fixing member 130 may be provided in various shapes.

[0055] For example, the fixing member 130 may have the form of a strip having a narrow width and a long length. In order to stably fix the upper plate 110 or the lower plate 120 by the fixing member 130, a hook structure may be formed at the end portion of the fixing member 130. More specifically, a portion bent from the main body of the fixing member 130 toward the upper plate 110 or the lower plate 120 may be formed at the end portion of the fixing member 130.

[0056] After the battery case 1 is placed on the lower plate 120 and the upper plate 110 is positioned above the battery case 1, the distance between the upper plate 110 and the lower plate 120 can be adjusted. The end portions of the fixing member 130 are coupled to the upper plate 110 and the lower plate 120 so that the positions of the upper plate 110 and the lower plate 120 can be fixed.

[0057] In another example, the fixing member 130 may have a structure that allows the fixing member 130 itself to extend in length. The two end portions 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 can be adjusted by the length extension of the fixing member 130.

[0058] Meanwhile, the elastic part 140 may be located below the lower plate 120. The elastic part 140 may include an elastic body 142 having a restoring force according to compression and a support part 144 supporting the lower surface of the elastic body 142. The support part 144 may be designed to have a step with the lower plate 120, whereby the elastic body 142 may be positioned below the upper surface of the lower plate 120. The support part 144 may support the elastic body 142 at a position lower than the upper surface of the lower plate 120. The support member 144 may be positioned to correspond to the mounting hole 122 formed in the lower plate 120. The support part 144 may have a shape in which the support part 144 extends downward from the edge of the mounting hole 122 perpendicular to the lower plate 120 and then extends toward the radial center therefrom. The support part 144 may have a cylindrical shape with an overall open upper part. The elastic body 142 may be positioned at a position corresponding to the mounting hole 122. The elastic body 142 may be located inside the mounting hole 122.

[0059] The elastic part 140 can be used to stably fix the battery case 1 between the upper plate 110 and the lower plate 120. By fixing the positions of the upper plate 110 and the lower plate 120 by the fixing member 130, the battery case 1 can receive a compressive force in the longitudinal direction, thereby fixing the position of the battery case 1. At this time, if the distance value between the upper plate 110 and the lower plate 120 is too small, the compressive force acting on the battery case 1 is formed to be too large, such that the battery case 1 may be damaged. In addition, if the distance value between the upper plate 110 and the lower plate 120 is too large, insufficient compressive force is applied to the battery case 1, which may make it difficult to stably fix the battery case 1. Therefore, the distance between the upper plate 110 and the lower plate 120 should be adjusted according to the size of the battery case 1. However, due to errors in design and process, the size of the battery case 1 may not be constant, which leads to the problem that the positions of the upper plate 110 and the lower plate 120 must be reset each time. However, in the electrolyte injection device 100 of the present embodiment, the elastic part 140 is provided on the lower side of the lower plate 120, thereby being able to adapt to battery cases 1 having different sizes and stably fixing the battery case 1. More specifically, the gap between the upper plate 110 and the lower plate 120, that is, the positions where the upper plate 110 and the lower plate 120 are fixed by the fixing member 130 are designed to be constant, and the compression level of the elastic body 142 is formed differently according to the length of the battery case 1, such that the battery case 1 can be stably fixed to the electrolyte injection device 100.

[0060] More specifically, the battery case 1 is disposed on the mounting hole 122 of the lower plate 120, and the lower surface of the battery case 1 may be located on the elastic part 140. The upper plate 110 may be located on the upper side of the battery case 1, wherein the sealing part 116 of the upper plate 110 may correspond to the open upper surface of the battery case 1. In a state where the sealing part 116 and the battery case 1 are on the same axis, the positions of the upper plate 110 and the lower plate 120 may be fixed by the fixing member 130, such that the battery case 1 can be fixed to the electrolyte injection device 100. At this time, the sealing part 116 may be in contact with the battery case 1. More specifically, the inner surface of the sealing part 116 may be in contact with the edge of the upper surface of the battery case 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 may be compressed by the battery case 1, and the battery case 1 is supported upward by the restoring force of the elastic body 142, such that the battery case 1 can be positioned more stably.

[0061] Meanwhile, Figure 1 and Figure 3 the electrolyte injection device 100 shown in may be in a state where the upper plate 110 is not in close contact with the battery case 1, which may be a state before the positions of the upper plate 110 and the lower plate 120 are fixed by the fixing member 130. In addition, Figure 2The electrolyte injection device 100 shown in the figure can be in a state where the upper plate 110 is in close contact with the battery case 1, and the positions of the upper plate 110 and the lower plate 120 are fixed by the fixing member 130.

[0062] Meanwhile, in Figure 1 , Figure 3 and Figure 4 , the fixing member 130 is depicted as if the fixing member 130 is fixed to the upper plate 110 and the lower plate 120 and can extend in length for the sake of convenience in explanation, and it can be different from the actual structure. Therefore, the fixing member 130 of the present embodiment can be set to have a fixed length and be attached to the upper plate 110 or the lower plate 120 in a detachable manner. When the two end portions 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 can be fixed. Before at least one of the two end portions of the fixing member 130 is fixed to the upper plate 110 or the lower plate 120, the fixing member 130 can be positioned to be separated from the upper plate 110 or the lower plate 120.

[0063] Meanwhile, the structure of the fixing member 130 can vary, and thus, the fixing member 130 can also be provided with the structure shown in Figure 1 , Figure 3 and Figure 4 . More specifically, the length of the fixing member 130 can be variable, and the fixing member 130 can be set to be in a state where the two end portions of the fixing member 130 are fixed to the upper plate 110 and the lower plate 120.

[0064] Meanwhile, when injecting the electrolyte into the interior of the battery case 1, if the battery case 1 and the sealing portion 116 are not aligned on the same axis, there is a problem of electrolyte leakage.

[0065] Figure 3 and Figure 4 are diagrams showing abnormal states that may occur during electrolyte injection.

[0066] Referring to Figure 3 and Figure 4 , during the process of injecting the electrolyte into the battery case 1 using the electrolyte injection device 100, a first abnormal state or a second abnormal state may occur, such that the electrolyte may leak out of the battery case 1. Here, the abnormal state can refer to a state where the sealing state between the upper surface of the battery case 1 and the sealing portion 116 is incomplete.

[0067] More specifically, as shown in Figure 3As shown in the figure, the battery case 1 can be positioned to tilt in a manner different from the operator's intention. That is, in the case of the first abnormal state, an acute angle can be formed between the lower surface of the battery case 1 and the lower plate 120. In the case of the first abnormal state, the slope of the lower surface of the battery case 1 and the lower plate 120 can be equal to or greater than a first value. Here, the first value can be greater than 0 and less than 90. In the case of the first abnormal state where the battery case 1 is positioned to tilt in this way, the battery case 1 and the sealing part 116 may not be on the same axis, and thus a gap may occur between the battery case 1 and the hopper 112, which may cause electrolyte leakage.

[0068] In addition, as Figure 4 shown in the figure, one side of the sealing part 116 may be damaged (A), which may cause electrolyte leakage. In the case of the second abnormal state where the sealing part 116 is damaged, even if the battery case 1 and the sealing part 116 are on the same axis, the space between the battery case 1 and the hopper 112 may not be airtightly sealed, so that the electrolyte may leak out of the battery case 1 during the injection process.

[0069] Meanwhile, conventionally, this abnormal state cannot be confirmed during electrolyte injection, but can only be confirmed by the leakage of the electrolyte after the electrolyte injection is completed, which leads to an increase in the defect rate of the battery cells.

[0070] However, the electrolyte injection device 100 of the present embodiment includes a sensor unit 150, and thus can quickly determine whether the electrolyte has leaked or the possibility of electrolyte leakage, and determine whether to inject the electrolyte.

[0071] The sensor unit 150 can be used to measure the pressure applied to the lower surface of the battery case 1. The sensor unit 150 can measure the pressure acting on the battery case 1 between the upper plate 110, the lower plate 120 and the elastic member 140. For this purpose, the sensor unit 150 can be located on the upper side of the elastic part 140. The sensor unit 150 can be located on the lower side of the battery case 1. In other words, during the electrolyte injection process, the battery case 1 can be arranged on the upper side of the elastic part 140 where the sensor unit 150 is located.

[0072] Conventional pressure sensors provide one pressure sensor per unit area and only collect the pressure values at specific positions within the unit area. Therefore, the collected pressure values are estimated as the pressure values formed over the entire corresponding unit area. Such pressure sensors are mainly used to measure the load of an object or measure the change in load over time, and in an electrolyte injection device, such pressure sensors have been used to confirm the amount of electrolyte injected into the battery case.

[0073] However, this embodiment is designed to confirm the pressure formed on the lower surface of the battery case 1 by position and to confirm whether the battery case 1 is correctly aligned between the upper plate 110 and the lower plate 120. Therefore, a conventional pressure sensor may not be preferable for achieving the above object.

[0074] In response to this request, the sensor unit 150 may include a sensor that measures the 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 surface pressure, has high resolution, and can have a small measurement error even when applied to a large area. The sensor unit 150 of this embodiment may be designed to cover a wide area by using the surface pressure sensor and can collect pressure values according to each position.

[0075] In particular, as described above, the battery case 1 has a cylindrical shape, and the lower surface of the battery case 1 may have a circular lower surface. Here, the sensor unit 150 may be arranged in a shape corresponding to the lower surface of the battery case 1.

[0076] In the first abnormal state as shown in Figure 3 and the second abnormal state as shown in Figure 4 , the battery case 1 having a circular lower surface may be tilted in one direction based on the center of the battery case 1. At this time, regardless of the direction in which the battery case 1 having a circular bottom surface is tilted, the sensor unit 150 may be located at a position corresponding to the direction in which the battery case 1 is tilted. That is, regardless of the direction in which the battery case 1 is tilted, the sensor unit 150 can more accurately measure the pressure formed on the lower surface of the battery case 1.

[0077] As shown in Figure 2 , the sensor unit 150 may be arranged in an annular shape. This can be used to measure the pressure formed at the edge of the lower surface of the battery case 1. In addition, the sensor unit 150 may include a plurality of sub-sensors 152 arranged at equal angles. At the same time, although Figure 2 shows that ten sub-sensors 152 are provided, the sensor unit 150 may also include fewer or more than ten sub-sensors 152. However, as the number of sub-sensors 152 included in the sensor unit 150 increases, the resolution improves. Therefore, in order for the sensor unit 150 to achieve the desired function, the number of sub-sensors 152 may preferably be at least four or more.

[0078] In this way, when the battery case 1 has a circular lower surface and the sensor unit 150 has an annular shape, regardless of the direction in which the battery case is tilted, the battery case 1 with the circular lower surface can have the sensor unit 150 positioned at a position corresponding to the direction in which the battery case 1 is tilted. That is, the sub-sensors 152 can simply be arranged in an annular shape along the edge of the lower surface of the battery case 1, so that the sensor unit 150 can accurately measure the pressure formed at the edge of the lower surface of the battery case 1, regardless of the direction in which the battery case 1 is tilted.

[0079] In contrast, if the battery case 1 has a lower surface with a shape other than a circular shape, depending on the direction in which the battery case 1 is tilted, the annular-shaped sensor unit 150 may not be located at a position corresponding to the edge of the lower surface of the battery case 1. That is, in this case, it may be difficult for the sensor unit 150 to accurately measure the pressure formed at the edge of the lower surface of the battery case 1 according to the direction in which the battery case 1 is tilted. In this case, the sensor unit 150 must be arranged as a plurality of sub-sensors 152 at different positions on the entire lower surface of the battery case 1 or in an area larger than the lower surface of the battery case 1, and such an arrangement has problems of reducing space efficiency and cost efficiency.

[0080] The sensor unit 150 includes a plurality of sub-sensors 152, and thus can measure in detail the pressure values formed on the lower surface of the battery case 1. The sensor unit 150 can individually obtain the values measured from each sub-sensor 152.

[0081] At this time, the pressure value detected by the sensor unit 150 can be referred to as a measured value. The measured value can include a first measured value and a second measured value, where the first measured value and the second measured value can be values collected from different sub-sensors 152 respectively. In the case where the number of sub-sensors 152 is ten as shown in Figure 2 the measured value can include a first measured value to a tenth measured value.

[0082] When an abnormal state occurs in the electrolyte injection device 100, the pressure acting on the lower surface of the battery case 1 may be uneven. When an abnormal state occurs in the electrolyte injection device 100, the first measured value and the second measured value obtained from the sub-sensors 152 at different positions may show a difference.

[0083] When a first abnormal state occurs in the electrolyte injection device 100, the pressure acting on the lower surface of the battery case 1 may be uneven. When the first abnormal state occurs, the first measured value obtained by the sub-sensor 152 located in the direction in which the battery case 1 is tilted may be higher, while the second measured value obtained by the sub-sensor 152 located in a different direction may be relatively lower.

[0084] In addition, even if a second abnormal state occurs in the electrolyte injection device 100, the pressure acting on the lower surface of the battery case 1 may be uneven. When a side portion of the sealing portion 116 is damaged due to aging or its shape is deformed, resulting in a decrease in the sealing force at that portion, a relatively low pressure may be applied to the lower surface of the battery case 1 corresponding to that portion. In other words, when a second abnormal state occurs, the pressure acting on the lower surface of the battery case 1 may deviate.

[0085] In this way, it is possible to determine whether an abnormal state has occurred based on the measured values acquired by the sensor unit 150. By comparing the calculation result of the measured values acquired by the sensor unit 150 with a predetermined condition, it is possible to determine whether an abnormal state has occurred.

[0086] Figure 5 is for explaining how Figure 1 the electrolyte injection device determines an abnormal state according to Figure 5 The photograph of

[0087] shows the result of detecting the pressure formed on the lower surface of the battery case 1 by the sensor, and the pressure values measured by the sensor are represented by shading and numbers. Figure 5 Referring to Figure 5 , the pressure acting on the lower surface of the battery case 1 can be acquired by position using the sensor unit 150, and it can be confirmed whether there is a deviation between them. In Figure 5 , T1 may be the edge of the lower surface of the battery case 1, and the sensor unit 150 can measure the pressure values formed along T1. Eight sub-sensors 152 corresponding to T1 are formed, and the sensor unit 150 can acquire the first measurement value to the eighth measurement value. More specifically, the first measurement value to the eighth measurement value may be 1, 1, 26, 33, 37, 59, 61, 32 respectively. In

[0088] Hereinafter, the experimental results of confirming whether there is a pressure deviation according to the position on the lower surface of the battery case 1 when there is a problem with the sealing state between the sealing portion 116 and the battery case 1 will be described.

[0089] In the experiment described below, the sensor unit 150 includes four sub-sensors 152, and the measured values include the first to fourth measured values obtained from each sub-sensor 152. This is to simplify the experiment by using the sensor unit 150 equipped with four sub-sensors 152, and the number of sub-sensors 152 of the present disclosure is not limited by the experimental content.

[0090] In addition, in the following experiment, each measured value is expressed as an exponential value of a reference value. Each measured value is displayed by converting each measured value into a relative value when the normal state value is set to 10 or 100. Here, the normal state may be a state in which the above abnormal state does not occur.

[0091] (Table 1)

[0092]

[0093] The air pressure in Table 1 may be the pressure value formed inside the battery case 1 located in the electrolyte injection device 100. Experimentally, when air is injected into the inside of the battery case 1 through the hopper 112 on the electrolyte injection device 100, the air pressure may be the pressure value formed inside the battery case 1.

[0094] In Table 1, the air pressure value may be expressed as a relative value with respect to the reference value. Here, the reference value may be the pressure value inside the battery case 1 desired by the operator or normally expected.

[0095] In Table 1, the reference value of the air pressure is set to 10. For example, if the pressure value inside the battery case 1 is expected to be 8 psi in the normal state and the actual measured value is 4 psi, the corresponding experimental result can be expressed as 5 in Table 1.

[0096] Referring to the above description, if the air pressure value is less than 10 in the experiment of Table 1, an abnormality may have occurred in the electrolyte injection device 100. More specifically, in Case 2 and Case 4 of Table 1, where the air pressure value is measured to be relatively small, it is confirmed that the battery case 1 is in an inclined state.

[0097] The total load value (kgf) may be the sum of the measured values detected by the sub-sensors 152 included in the sensor unit 150. In this experiment, the number of sub-sensors 152 may be four, and the total load value may be the sum of the first to fourth measured values. In addition, the maximum load value (kgf) and the minimum load value (kgf) may be the maximum and minimum values among the first to fourth measured values.

[0098] In addition, in Table 1, the total load value, the maximum load value, the minimum load value, and the average value of the total load can be expressed as relative values. Here, the reference value can correspond to the compressive force formed in the elastic body 142 in the normal state.

[0099] In Table 1, the reference value of the total load is set to 100. For example, in the normal state, the compressive force formed in the elastic body 142 or the pressure value obtained from the sensor unit 150 thereby is expected to be 70 kgf, and if the sum of the pressure values actually obtained from the sub-sensors 152 is 60 kgf, it can be expressed as 85.7 in the following table.

[0100] When comparing the total load values of each case, it is found that the values of Case 2 and Case 4 are higher than those of Case 1 and Case 3 aligned in the flat state. This may be because when the battery case 1 is placed flat, the battery case 1 appropriately forms a compressive force in the elastic part 140. Therefore, the alignment state of the battery case 1 can be estimated by the sum of the measured values obtained from the sensor unit 150. Whether an abnormal state has occurred can be determined by the sum of the measured values obtained from the sensor unit 150.

[0101] In addition, when comparing the relative standard deviations (%) of each case, it is found that the values of Case 2 and Case 4 are lower than those of Case 1 and Case 3 with a flat alignment state. This may mean that when the battery case 1 is placed flat, the deviation of the pressure values formed on the lower surface of the battery case 1 is reduced. Therefore, the alignment state of the battery case 1 can be estimated by the relative standard deviation of the measured values obtained from the sensor unit 150. Whether an abnormal state has occurred can be determined by the relative standard deviation of the measured values obtained from the sensor unit 150.

[0102] In this way, when an abnormal state occurs, a deviation may occur between the measured values obtained from the sensor unit 150. The electrolyte injection device 100 of the present embodiment can confirm the pressure distribution formed on the lower surface of the battery case 1 by the measured values obtained by the sensor unit 150. In addition, based on this, the electrolyte injection device 100 can determine whether an abnormal state has occurred.

[0103] Meanwhile, although not shown in the figure, the electrolyte injection device 100 of the present embodiment may include a control unit that commonly controls the operation of the electrolyte injection device 100.

[0104] The control unit can receive the measurement values collected from the sensor unit 150. The control unit can receive separately the measurement values obtained from each sub-sensor 152. The control unit can also calculate the measurement values obtained from each sub-sensor 152 to calculate the sum, average, standard deviation, etc. between the measurement values. The control unit can control the output unit included in the electrolyte injection device 100 to display the processed data, i.e., the pressure value or the result value calculated therefrom, or can send a request to an output device connected to the electrolyte injection device 100 for operation. In this case, the electrolyte injection device 100 can also include a communication unit for communicating with an external device.

[0105] The control unit can confirm whether an abnormal state has occurred in the electrolyte injection device 100 based on the pressure value collected from the sensor unit 150. The control unit can control the electrolyte injection device 100 to inject the electrolyte based on the pressure value collected from the sensor unit 150. The control unit can confirm whether the calculation result of the collected data meets a predetermined condition. If the calculation result meets the predetermined condition, the control unit can control the electrolyte injection device 100 to perform the injection of the electrolyte.

[0106] Here, there can be multiple predetermined conditions, and the control unit can determine whether each condition is satisfied and determine whether to inject the electrolyte. For example, the control unit can control the electrolyte injection device 100 to inject the electrolyte when the first condition and the second condition are satisfied. Additionally, the control unit can control the electrolyte injection device 100 not to inject the electrolyte when either the first condition or the second condition is not satisfied.

[0107] However, as described above, the data processing and manipulation do not necessarily have to be performed by the control unit of the electrolyte injection device 100. According to an embodiment, the sensor unit 150 can separately include a control unit, and the above data can be processed by the control unit included in the sensor unit 150.

[0108] Meanwhile, the predetermined conditions herein can be set in various ways.

[0109] The determination of the predetermined conditions described below is described as being performed by the control unit, where the control unit can be installed on the electrolyte injection device 100 or can be independently provided in the sensor unit 150.

[0110] As an example of the predetermined condition, the control unit can 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 can compare the sum of the first measurement value to the third measurement value with a first reference value. If the difference between the sum of the first measurement value to the third measurement value and the first reference value is within a predetermined range, the control unit can determine that the first condition is satisfied.

[0111] Here, the first reference value can be a predetermined value, and the first reference value can be a value set experimentally as shown in Table 1 above, or can be a value set by calculation.

[0112] The first reference value can be related to the compressive force formed on the elastic body 142. When designing the electrolyte injection device 100, the first reference value can be related to the pressure value expected to act on the elastic body 142 through the battery case 1. The first reference value can be the pressure value itself expected to act on the elastic body 142 in the normal state. Alternatively, the first reference value can be the total pressure value expected to be collected by the sensor unit 150 in the normal state.

[0113] Alternatively, the first reference value can be the pressure value formed on the lower surface of the battery case 1 when no abnormal state occurs, as shown in Table 1 above. More specifically, the sum of the measured values formed on the lower surface of the battery case 1 measured by the sensor unit 150 when an abnormal state occurs and when no abnormal state occurs can be calculated. This process can be repeated experimentally, thereby determining the first reference value and the predetermined range.

[0114] In another example of the predetermined conditions, the control unit can consider the dispersion of the values collected from the sub-sensor 152. Here, the dispersion can be calculated as the relative standard deviation. Alternatively, in addition to the relative standard deviation, the dispersion can be calculated by another calculation formula that can represent the dispersion of multiple values. The control unit can compare the relative standard deviation of the first measurement value to the third measurement value with the second reference value. When the relative standard deviation of the first measurement value to the third measurement value is less than the second reference value, the control unit can determine that the second condition is satisfied.

[0115] Here, the second reference value can be a predetermined value. The second reference value can be a value set experimentally as shown in Table 1 above, or can be a value set by calculation.

[0116] The second reference value can be related to the outflow air pressure. The outflow air pressure can refer to the magnitude of the air pressure flowing out between the battery case 1 and the sealing portion 116 when air is injected into the interior of the battery case 1 through the hopper 112 on the electrolyte injection device 100. More specifically, the outflow air pressure can be calculated as the difference between the air pressure p1 expected to be formed inside the battery case 1 and the actual air pressure p2 formed inside the battery case 1, and the outflow air pressure can be calculated as "outflow air pressure = p1 - p2". When the value of the outflow air pressure is large, it can be inferred that there is a problem with the sealing condition between the sealing portion 116 and the battery case 1.

[0117] The second reference value can be determined through experiments. Through experiments, the outflow air pressure when an abnormal state occurs can be measured, and the relative standard deviation of the measured value at this time can be calculated. More specifically, when the value of the outflow air pressure is greater than a predetermined value, it can be determined that an abnormal state has occurred in the electrolyte injection device 100. In addition, when the value of the outflow air pressure is greater than the predetermined value in this way, the relative standard deviation of the pressure value formed on the lower surface of the battery case 1 as shown in Table 1 above can be calculated, and the second reference value can be determined based on this. Additionally, when determining the second reference value, the relative standard deviation of the pressure value on the lower surface of the battery case 1 when no abnormal state occurs can be considered. In this way, based on the second reference value determined through experiments, it can be determined whether an abnormal state has occurred.

[0118] Next, an electrolyte injection method based on the above explanation will be described. The electrolyte injection method described below can be performed by means of the above-described electrolyte injection device 100. Therefore, the above content can be applied to all the following descriptions, and the same descriptions are omitted to avoid redundant descriptions.

[0119] Figure 6 is a flowchart showing an electrolyte injection method according to an embodiment of the present disclosure. Figure 7 is a flowchart embodying a part of the electrolyte injection method according to Figure 6 the electrolyte injection method.

[0120] Referring to Figure 6 , the electrolyte injection method (S100) according to the present embodiment may include: a step (S110) of placing the battery case 1 in the mounting hole 122 of the lower plate 120, a step (S120) of fixing the positions of the upper plate 110 located above the battery case 1 and the lower plate 120 on which the battery case 1 is placed, a step (S130) of determining whether an abnormal condition has occurred based on the pressure value collected by the sensor unit 150, a step (S140) of re-fixing the position of the upper plate 110 or the lower plate 120 if it is determined that an abnormal condition has occurred, a step (S150) of checking the condition of the sealing portion 116 if it is determined that an abnormal condition has occurred, and a step (S160) of injecting the electrolyte into the interior of the battery case 1 if it is determined that no abnormal condition has occurred.

[0121] Next, each step will be described in more detail.

[0122] The battery case 1 can be placed in the mounting hole 122 of the lower plate 120 (S110). The elastic portion 140 can be located at a position corresponding to the mounting hole 122 on the lower side of the lower plate 120. The battery case 1 can be inserted into the mounting hole 122 and located on the elastic body 142 of the elastic portion 140.

[0123] The position of the upper plate 110 that can be fixed to the upper side of the battery case 1 or the lower plate 120 on which the battery case 1 is disposed can be fixed (S120). Thereby, the movement of the battery case 1 is restricted, and the battery case 1 can be fixed inside the electrolyte injection device 100. More specifically, the positions of the upper plate 110 and the lower plate 120 can be fixed by the fixing member 130. The upper plate 110 and the lower plate 120 can be fixed in a state where the battery case 1 is pressurized so that the elastic body 142 located on the lower surface of the battery case 1 can be compressed. Due to the restoring force of the elastic body 142, the upper plate 110, the lower plate 120, and the battery case 1 are pressed against each other, so that the battery case 1 can be stably fixed between the upper plate 110 and the lower plate 120. At this time, the battery case 1 can be located on the same axis as the sealing part 116.

[0124] Meanwhile, when the battery case 1 is fixed to the upper plate 110 and the lower plate 120, the electrolyte can be injected into the battery case 1 through the hopper 112 of the upper plate 110. At this time, the sealing part 116 can be located between the battery case 1 and the hopper 112. The sealing part 116 can hermetically seal the gap between the battery case 1 and the hopper 112, thereby preventing electrolyte leakage during electrolyte injection. However, as described above, if the battery case 1 is not arranged on the same axis as the sealing part 116, or if the sealing part 116 is damaged, the electrolyte may leak out of the battery case 1.

[0125] However, in this embodiment, it is possible to determine whether an abnormal state has occurred based on the pressure value collected by the sensor unit 150 (S130). The sensor unit 150 can measure the pressure formed on the lower surface of the battery case 1. The sensor unit 150 can include a plurality of sub-sensors 152, and thus can obtain pressure values corresponding to each position. The electrolyte injection device 100 can confirm whether an abnormal state has occurred based on the acquired measurement values. The abnormal state can include a first abnormal state and a second abnormal state, and for this, reference is made to Figure 3 and Figure 4 the description. Here, the step (S130) of determining whether an abnormal state has occurred can be performed before injecting the electrolyte.

[0126] The measured values obtained from the sensor unit 150 can be processed by a pre-stored calculation formula. If the processed calculated value does not meet a predetermined condition, the control unit can determine that an abnormal state has occurred in the electrolyte injection device 100. In this way, the calculation process of the measured values and the determination of whether the predetermined condition is met can be performed by the control unit, where the control unit can be included in the sensor unit 150 or can be included in the electrolyte injection device 100. Additionally, the control unit correctively controls the operation of the electrolyte injection device 100, and thus, even if not specifically described, it can be understood that in this embodiment, the calculation of the determination result and the control of the component operation are performed by the control unit.

[0127] Meanwhile, depending on the determination result of step (S130), the electrolyte injection method S100 can proceed to step (S140), step (S150), or step (S160).

[0128] In one example, if it is not determined that an abnormal state has occurred, the electrolyte injection device 100 can inject the electrolyte into the interior of the battery case 1 (S160). The electrolyte can be injected through the hopper 112 of the upper plate 110.

[0129] In another example, if it is determined that an abnormal state has occurred, the electrolyte injection device 100 can re-fix the positions of the upper plate 110 and the lower plate 120 (S140) or confirm the state of the sealing portion 116 (S150). This can eliminate the cause of the above-mentioned first abnormal state or second abnormal state.

[0130] Here, after performing step (S140) or step (S150), step (S130) can be determined again. This can confirm whether the cause of the abnormal state has been eliminated. Depending on the re-determination result of step (S130), the electrolyte injection method S100 can proceed to step (S140), step (S150), or step (S160).

[0131] If it is determined that an abnormal state has occurred, the electrolyte injection device 100 can re-fix the positions of the upper plate 110 and the lower plate 120 (S140). This can eliminate the cause of the first abnormal state. This can correct the misalignment between the sealing portion 116 and the battery case 1. This can ensure that the sealing portion 116 and the battery case 1 are on the same axis. Here, since the content of step (S140) is the same as or similar to the content of step (S120), it can be interpreted as re-executing step (S120) according to the determination result of step (S130).

[0132] If it is determined that an abnormal state has occurred, the fixing of the positions of the upper plate 110 and the lower plate 120 by the fixing member 130 can be released. As a result, the distance between the upper plate 110 and the lower plate 120 can be increased. To this end, the upper plate 110 can move upward, or the lower plate 120 can move downward. The fixing of the positions between the upper plate 110 and the lower plate 120 is released, so that the battery case 1 can be separated from the upper plate 110, and the upper surface of the battery case 1 can be separated from the sealing portion 116 of the upper plate 110.

[0133] Then, the positions of the upper plate 110 and the lower plate 120 can be fixed again by the fixing member 130. As a result, the battery case 1 can be fixed in the electrolyte injection device 100 again. At this time, the sealing portion 116 and the upper surface of the battery case 1 can be in close contact with each other.

[0134] When the positions of the upper plate 110 and the lower plate 120 are fixed by the fixing member 130 and the battery case 1 is installed on the electrolyte injection device 100, the sensor unit 150 can measure the pressure formed on the lower surface of the battery case 1. Based on the pressure value collected by the sensor unit 150, it can be determined again whether an abnormal state has occurred. In this way, after step (S140) is executed, step (S130) can be executed again.

[0135] Step (S140) and step (S130) can be repeatedly executed. In other words, after the positions of the upper plate 110 and the lower plate 120 are fixed again, it can be determined again whether an abnormal state has occurred based on the value obtained by the sensor unit 150, and if it is determined that an abnormal state has occurred, the positions of the upper plate 110 and the lower plate 120 can be fixed again.

[0136] The above steps (S140) and step (S130) can be repeated a preset number of times (SN). Here, the preset number of times (SN) can be calculated in advance or can be a pre-input value. For example, the preset number of times (SN) can be 3 times, and if it is still confirmed that an abnormal state has occurred after steps (S140) and (S130) have been repeated 3 times, step (S150) can be executed.

[0137] To this end, the electrolyte injection device 100, more specifically, the control unit, can calculate the number of repetitions (RN). Here, the number of repetitions (RN) can be the number of repetitions of step (S140).

[0138] For example, the initial value of the repetition number (RN) can be 0 and can be incremented by 1 as the step (S140) is repeated. Thus, if the preset repetition number (SN) is 1, the step (S140) is executed, and then the step (S130) can be executed. Depending on the determination result of the step (S130), the step (S150) or the step (S160) can be executed.

[0139] Therefore, if it is determined through the step (S130) that an abnormal state has occurred, the electrolyte injection method (S100) of the present embodiment may further include a step (S132) of comparing the repetition number (RN) with the preset repetition number (SN). Here, if the repetition number (RN) is less than the preset repetition number (SN), the step (S140) can be executed. If the repetition number (RN) is equal to or greater than the preset repetition number (SN), the step (S150) can be executed.

[0140] If it is determined that an abnormal state has occurred, the electrolyte injection device 100 can confirm the condition of the sealing part 116 (S150). This can eliminate the cause of the second abnormal state. If the sealing part 116 is damaged, worn, or deformed, the gap between the sealing part 11 and the battery case 1 may not be sealed, such that the pressure formed on the lower surface of the battery case 1 may deviate. If damage, wear, or deformation of the sealing part 116 is confirmed, the sealing part 116 can be replaced. At this time, as the step (S160) is executed, the repetition number (RN) can be set back to the initial value 0.

[0141] After confirming that there is no abnormality in the sealing part 116 or after the replacement of the sealing part 116 is completed, the battery case 1 can be fixed in the electrolyte injection device 100 by the upper plate 110, the lower plate 120, and the elastic part 140. When the positions of the upper plate 110 and the lower plate 120 are fixed by the fixing member 130 and the battery case 1 is installed in the electrolyte injection device 100, the sensor unit 150 can measure the pressure formed on the lower surface of the battery case 1. Based on the pressure value collected by the sensor unit 150, it can be determined again whether an abnormal state has occurred. In this way, after the step (S150) is executed, the step (S130) can be executed again.

[0142] Here, the confirmation or replacement of the sealing part 116 can be performed in a state where the upper plate 110 and the battery case 1 are separated, and thus it can also be interpreted that after the step (S150) is executed, the step (S120) or the step (S110) is executed again.

[0143] Meanwhile, referring to Figure 7 , it can be determined whether an abnormal state has occurred in the electrolyte injection device 100 based on predetermined conditions. Here, the predetermined conditions may include a first condition and a second condition.

[0144] As shown in Figure 7 the method (S200) for determining whether an abnormal state has occurred through the electrolyte injection device 100 may include:

[0145] a step (S210) of determining whether the calculation result of the measured value obtained from the sensor unit 150 satisfies a first condition, a step (S220) of determining whether the calculation result of the measured value obtained from the sensor unit 150 satisfies a second condition, a step (S230) of determining that an abnormal state has occurred in the electrolyte injection device 100 if the first condition or the second condition is not satisfied, and a step (S240) of determining that no abnormal state has occurred in the electrolyte injection device 100 if the first condition and the second condition are satisfied,

[0146] The control unit may determine whether the calculation result of the acquired measured value satisfies the first condition (S210). The first condition may relate to whether the difference between the sum of the measured values and a first reference value is within a predetermined range. If the difference between the sum of the measured values and the first reference value is within the predetermined range, the control unit may determine that the first condition is satisfied. Here, the first reference value may be a value obtained through experiments or theory.

[0147] The control unit may determine whether the calculation result of the acquired measured value satisfies the second condition (S220). The second condition may relate to whether the relative standard deviation value of the measured values is less than a second reference value. If the relative standard deviation of the measured values is less than the second reference value, the control unit may determine that the second condition is satisfied. Here, the second reference value may be a value obtained through experiments.

[0148] If the first condition or the second condition is not satisfied, 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, steps (S140) or step (S150) may be performed as described in Figure 6 . Here, step (S132) may be performed before performing step (S140) or step (S150), and step (S140) or step (S150) may be performed according to the determination result of step (S132).

[0149] If the first condition and the second condition are satisfied, the control unit may determine that no abnormal condition has occurred in the electrolyte injection device 100 (S240). If it is determined that no abnormal condition has occurred in the electrolyte injection device 100, steps (S160) may be performed as described in Figure 6 .

[0150] Although the present invention has been described in detail above with reference to the preferred embodiments of the present invention, those skilled in the art will understand that the scope of the present disclosure is not limited thereto, and various modifications and improvements can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined in the appended claims and their equivalents.

[0151] [Description of Reference Numerals]

[0152] 1: Battery case

[0153] 100: Electrolyte injection device

[0154] 110: Upper plate

[0155] 112: Hopper

[0156] 114: Electrolyte injection port

[0157] 116: Sealing part

[0158] 120: Lower plate

[0159] 122: Mounting hole

[0160] 130: Fixing member

[0161] 140: Elastic part

[0162] 150: Sensor unit.

Claims

1. An electrolyte injection device for injecting electrolyte into a battery case, the device comprising: an upper plate having a built-in hopper for injecting electrolyte into the battery case at an upper side of the battery case, a lower plate having a mounting hole through which a lower surface of the battery case is placed, and an elastic part located at a position corresponding to the mounting hole on a lower side of the lower plate and compressed according to a pressure applied to the lower surface of the battery case, wherein a sensor unit for measuring a pressure applied to the lower surface of the battery case is positioned on an upper part of the elastic part.

2. The electrolyte injection device according to claim 1, wherein: the electrolyte injection device further comprises a sealing part for hermetically sealing a gap between an upper surface of the battery case and a lower surface of the hopper.

3. The electrolyte injection device according to claim 1, wherein: the sensor unit is positioned corresponding to an edge of the lower surface of the battery case.

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

5. The electrolyte injection device according to claim 1, wherein: a measured value of the sensor unit includes pressure values according to each position, and an abnormal state is determined based on the measured value.

6. The electrolyte injection device according to claim 5, wherein: the abnormal state includes a first abnormal state and a second abnormal state. In the first abnormal state, an acute angle is formed between the lower surface of the battery case and the lower plate. In the second abnormal state, a sealing state between the upper surface of the battery case and the upper plate is incomplete.

7. The electrolyte injection device according to claim 5, wherein: whether an abnormal state has occurred is determined by whether a calculation result of the measured value satisfies a predetermined condition.

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

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

10. The electrolyte injection device according to claim 7, wherein: the sensor unit comprises a plurality of sub-sensors, the predetermined condition includes a second condition, and it is determined that the second condition is satisfied when a relative standard deviation of measured values obtained from the plurality of sub-sensors is less than a second reference value.

11. An electrolyte injection method using the electrolyte injection device according to claim 1, the method comprising the steps of: placing a battery case in a mounting hole of a lower plate, fixing positions of the upper plate located at an upper side of the battery case and the lower plate on which the battery case is placed, Measure the pressure formed on the lower surface of the battery case through a sensor unit to obtain a measurement value, and determine whether an abnormal state has occurred based on the measurement value, and Inject an electrolyte into the interior of the battery case when it is determined that no abnormal state has occurred.

12. The electrolyte injection method according to claim 11, including: When it is determined that an abnormal state has occurred, re-fix the positions of the upper plate and the lower plate.

13. The electrolyte injection method according to claim 12, wherein: After re-fixing the positions of the upper plate and the lower plate, Determine again whether an abnormal state has occurred.

14. The electrolyte injection method according to claim 12, wherein: After determining whether an abnormal state has occurred, The method further includes comparing the number of repetitions with a preset number when it is determined that an abnormal state has occurred, wherein the number of repetitions is increased by 1 by performing re-fixing.

15. The electrolyte injection method according to claim 14, wherein: Perform re-fixing when the number of repetitions is less than the preset number.

16. The electrolyte injection method according to claim 14, wherein: When the number of repetitions is equal to or greater than the preset number of repetitions, check the state of the sealing portion located at the lower part of the upper plate.

17. The electrolyte injection method according to claim 12, wherein: Determining whether an abnormal state has occurred includes determining whether the calculation result of the measurement value satisfies a first condition.

18. The electrolyte injection method according to claim 17, wherein: Determining whether an abnormal state has occurred further includes determining whether the calculation result of the measurement value satisfies a second condition.

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