Charging and discharging fixture for impedance measurement of battery cells

Abstract

The charging / discharging fixture for measuring the impedance of a battery cell of the present invention includes: a fixture body on which a battery cell is mounted in a longitudinal direction; a first bus bar and a second bus bar, the first bus bar and the second bus bar being arranged on both sides of the fixture body, and lead portions at both ends of the battery cell being connected to the first bus bar and the second bus bar; an impedance measuring board mounted on the fixture body; and a wire for impedance measurement, the wire for impedance measurement forming an impedance measurement circuit by connecting the first bus bar, the impedance measuring board, and the second bus bar, wherein a portion of the wire for impedance measurement has a portion that faces a wide surface of the battery cell and extends in the longitudinal direction of the battery cell.

Description

Technical Field

[0001] The present invention relates to a charging and discharging fixture for impedance measurement of a battery cell.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0124886, filed on September 17, 2021, and the entire contents of this Korean Patent Application are incorporated herein by reference. Background Art

[0003] Recently, secondary batteries, which can be charged and discharged, have been widely used as energy sources for wireless mobile devices. Furthermore, secondary batteries have attracted attention as energy sources for electric vehicles and hybrid electric vehicles, which are proposed as solutions to air pollution caused by existing gasoline and diesel vehicles that use fossil fuels. Consequently, due to the advantages of secondary batteries, the types of applications using them are currently becoming more diverse, and they are expected to be used in a wide range of fields and products in the future.

[0004] Depending on the composition of the electrolyte and the electrode, such secondary batteries can be classified into lithium-ion batteries, lithium-ion polymer batteries, lithium polymer batteries, etc., and among them, the use of lithium-ion polymer batteries, which are less likely to leak electrolytes and are easy to manufacture, is increasing. Generally, depending on the shape of the battery casing, secondary batteries are classified into cylindrical batteries and prismatic batteries in which the electrode assembly is embedded in a cylindrical or prismatic metal can and pouch-type batteries in which the electrode assembly is embedded in a pouch-type casing of an aluminum laminate sheet. The electrode assembly embedded in the battery casing consists of a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode, and is an electric power generating element capable of charging and discharging. The electrode assembly is classified into: a jelly roll type, which is wound with a separator between a long sheet-shaped positive electrode and a negative electrode coated with an active material; or a stacked type, in which a plurality of positive electrodes and negative electrodes of predetermined sizes are stacked sequentially with a separator between them.

[0005] To check the safety and performance of these secondary batteries, various tests can be performed. Among these, there is a growing reliance on methods that evaluate battery safety and performance by measuring the impedance of battery cells. By measuring the impedance of battery cells in this way, key factors such as lifespan, capacity, and state of charge can be estimated.

[0006] The impedance measurement results of a battery cell change depending on the length change or movement of the measuring wire (electrical wire). In the case of cylindrical batteries with short lengths and large impedance values, the influence of the electrical wire is relatively small. However, in the case of medium or large pouch-type batteries with long lengths and small impedance values, the measured impedance value has a large deviation depending on the length or movement of the electrical wire. The impedance of such a battery cell can be measured by installing the battery cell in a charging and discharging fixture that can be displaced in the longitudinal direction of the battery cell.

[0007] Specifically, the impedance is measured in such a manner that leads of the battery cells each having a different polarity are mounted on charge and discharge bus bars mounted on both sides of the charge and discharge jig, and electric wires are connected to the charge and discharge bus bars.

[0008] Conventionally, the impedance of a battery cell is measured in the following manner: a battery cell and a charging and discharging fixture for impedance measurement in which the battery cell is installed are installed in a temperature chamber, and an impedance measuring device (e.g., an EIS measuring device) and the charging and discharging fixture are connected from the outside with a wire. Because the impedance measuring device and the charging and discharging fixture occupy a large volume, there are difficulties in installing the impedance measuring device and the charging and discharging fixture in the temperature chamber. Therefore, when the impedance measuring device is installed outside the temperature chamber, the length of the wire connecting the battery cell and the impedance measuring device naturally increases. Therefore, as the length of the wire increases, the impedance component (inductance) according to the length of the wire increases, which acts as noise in the impedance measurement of the battery cell, making it difficult to accurately measure the impedance of the battery cell. Moreover, when the wire extends a certain length outside the battery cell, the magnetic field caused by the current flowing through the battery cell and the magnetic field caused by the wire cannot be offset, and therefore the impedance interference effect caused by the noise caused by the magnetic field inevitably occurs. This problem is more serious in the case of a medium or large pouch-type battery having a long cell length and a small impedance value.

[0009] Therefore, there is a need to develop a device capable of more accurately measuring the impedance of a battery cell by reducing the length of a wire used for impedance measurement while mitigating the influence of a magnetic field caused by the current of the battery cell and the wire.

[0010] [Prior art literature]

[0011] Korean Patent Registration No. 10-1359902 Summary of the Invention

[0012] Technical issues

[0013] The present invention is directed to providing a charging and discharging jig for impedance measurement of a battery cell, in which a wire for impedance measurement can be formed short and installed to extend parallel to the battery cell while facing the battery cell.

[0014] Technical Solution

[0015] A charging and discharging fixture for impedance measurement of a battery cell according to the present invention for solving the above-mentioned problems includes: a fixture body on which a battery cell is mounted in a longitudinal direction; a first bus bar and a second bus bar, the first bus bar and the second bus bar being arranged on both sides of the fixture body, and lead portions at both ends of the battery cell being connected to the first bus bar and the second bus bar, respectively; an impedance measurement board, the impedance measurement board being arranged in the fixture body; and a wire for impedance measurement, the wire for impedance measurement connecting the first bus bar, the impedance measurement board and the second bus bar to constitute an impedance measurement circuit, and a portion of the wire for impedance measurement having a portion facing a wide surface of the battery cell and extending in the longitudinal direction of the battery cell.

[0016] The wires for impedance measurement may include a signal line configured to apply an AC signal to the battery cell; and a sensing line configured to measure a voltage of the battery cell.

[0017] For example, the first bus bar and the second bus bar may each be configured as an upper bus bar and a lower bus bar, and the wire for impedance measurement may be connected to the upper bus bar or the lower bus bar.

[0018] As a specific example, the upper bus bar of the first bus bar and the second bus bar may each be separated into two bus bars, and the signal line and the sensing line may be connected to each of the separated bus bars.

[0019] As an example, the impedance measurement board may include: an AC signal source and an ammeter, the AC signal source and the ammeter being connected to the signal line; and a voltmeter being connected to the sensing line.

[0020] Specifically, the impedance measurement board may be installed at the lower portion of the jig body, and the conductive wire for impedance measurement may constitute a loop connecting the first bus bar, the impedance measurement board, and the second bus bar, and a portion of the conductive wire constituting the loop may extend in the longitudinal direction of the battery cell along the bottom surface of the jig body.

[0021] As another example, the charging and discharging jig may further include bases installed on both sides of the lower portion of the jig body, and the impedance measurement board may be installed on the bases or a lower portion of the jig body adjacent to the bases.

[0022] As another example, the charging and discharging jig may further include bases installed at both sides of a lower portion of the jig body, and the impedance measurement board may be installed on a measurement board support coupled to the bases.

[0023] As another example, a wire support member configured to support a wire for impedance measurement extending along the bottom surface of the jig body in the longitudinal direction of the battery cell may be installed on the bottom surface of the jig body.

[0024] As another example, fixing jigs configured to fix both sides of the wire extending in the longitudinal direction of the battery cell along the bottom surface of the jig body may be installed at both sides of the bottom surface of the jig body.

[0025] As an example, the impedance measurement board may be installed in the middle of the bottom surface of the jig body, and the portion of the wire constituting the loop may be pulled out to both sides of the impedance measurement board and extend toward each of the first bus bar and the second bus bar.

[0026] As another exemplary embodiment of the present invention, the fixture body may include a fixed block and a movable block, the movable block is slidably coupled to the fixed block, the first bus bar may be installed on one side of the fixed block, and the second bus bar may be installed on one side of the movable block.

[0027] As an example, the movable block may be slidably coupled to an upper surface of the fixed block.

[0028] As a specific example, guide slits may be formed on both sides of one of the fixed block and the movable block in the width direction, and a sliding support member may be installed in the other of the fixed block and the movable block, the sliding support member being inserted into the guide slits.

[0029] More specifically, each of the sliding support members may have a body portion inserted into the guide slit and screwed to the fixed block or the movable block, and a head portion having a width greater than that of the guide slit.

[0030] Beneficial effects

[0031] According to the present invention, by reducing the length of the wire used for impedance measurement, the influence of the inductance according to the length of the wire can be minimized, thereby reducing noise of the impedance measurement.

[0032] In addition, since the conductive wire for impedance measurement has a structure that can be installed to face the wide surface of the battery cell and extend in the longitudinal direction of the battery cell, the impedance of the battery cell can be measured more accurately by canceling the magnetic field caused by the battery cell and the magnetic field caused by the conductive wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram illustrating the difference between a conventional impedance measuring device and the impedance measuring mechanism of the charging and discharging jig for impedance measurement of the present invention.

[0034] Figure 2 is a perspective view of a charging and discharging jig for impedance measurement of a battery cell according to an exemplary embodiment of the present invention.

[0035] Figure 3 1 is a schematic diagram illustrating a connection relationship between a wire for impedance measurement and an impedance measurement board according to the present invention, and an impedance measurement circuit composed of the wire and the measurement board.

[0036] Figure 4 yes Figure 2 Bottom view of the charge and discharge fixture for impedance measurement.

[0037] Figure 5 is a bottom view of a charging and discharging jig for impedance measurement of a battery cell according to another exemplary embodiment of the present invention.

[0038] Figure 6 is a bottom view of a charging and discharging jig for impedance measurement of a battery cell according to yet another exemplary embodiment of the present invention.

[0039] Figure 7 is a perspective view of a charging and discharging jig for impedance measurement of a battery cell according to another exemplary embodiment of the present invention.

[0040] Figure 8 yes Figure 7 Bottom view of the charge and discharge fixture for impedance measurement. DETAILED DESCRIPTION

[0041] Hereinafter, the detailed configuration of the present invention will be described in detail with reference to the accompanying drawings and various exemplary embodiments. The exemplary embodiments described below are schematically shown to help understand the present invention, and the accompanying drawings may not be illustrated according to the actual scale, but the sizes of some components may be exaggerated to help understand the present invention.

[0042] In the present invention, because various modifications can be made and various forms can be applied, specific exemplary embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the invention to the specific disclosed forms, which should be understood to include all modifications, equivalents and alternatives included in the spirit and scope of the invention.

[0043] As described above, the present invention provides a charging and discharging jig for impedance measurement of a battery cell 10 , in which a wire L for impedance measurement can be formed short and installed to extend parallel to the battery cell 10 while facing the battery cell 10 .

[0044] Figure 1 4 is a schematic diagram illustrating the difference between a conventional impedance measurement device and the impedance measurement mechanism of the impedance measurement board 400 of the present invention.

[0045] Conventionally, a battery cell and a charging and discharging fixture for impedance measurement are installed in a temperature chamber, and an impedance measuring device (e.g., an EIS measuring device) and a charging and discharging device are installed outside the temperature chamber to charge and discharge the battery cell and simultaneously measure the impedance of the battery cell. Because the impedance measuring device and the charging and discharging device occupy a considerable volume, the impedance measuring device and the charging and discharging device cannot be installed in the temperature chamber due to the size limitation of the space of the temperature chamber. Therefore, during the charging and discharging of conventional battery cells, the construction of the wires for impedance measurement must be as follows: Figure 1 As shown in (a). Figure 1 When measuring the impedance of a battery cell, the wire forms a loop shape connecting the two leads of the battery cell and the impedance measuring device (not shown). In this case, as described above, Figure 1 As shown in (a), when the impedance measuring device is installed outside the temperature chamber, the loop of the wire connected to the battery cell lead becomes longer. Accordingly, the length of the wire increases, and the inductance component of the wire increases, which acts as noise when measuring the impedance of the battery cell. In addition, because the wire has a long extended form, there is a problem that the arrangement of the wire changes slightly every time the wire is connected to the battery cell, and the impedance measurement result changes accordingly. In addition, in Figure 1 In the case of (a), the current flowing along the battery cell generates a magnetic field, which may interfere with the impedance value of the battery cell.

[0046] On the other hand, as in Figure 1 As shown in (b), when the wire for impedance measurement is placed adjacent to the battery cell, the length of the wire is shortened, and thus the influence of inductance can be significantly reduced. Figure 1 In (b), the lead wire for impedance measurement faces the wide surface of the battery cell and extends parallel to the longitudinal direction of the battery cell. Figure 1 As shown in (b), since the direction of the current flowing along the battery cell is opposite to the direction of the current flowing along the wire, the direction of the magnetic field caused by the current is also opposite. Figure 1 As shown in (b), when a wire (circuit) for impedance measurement can be constructed, the magnetic fields of the battery cell and the wire can cancel each other. In this case, the impedance of the battery cell can be measured more accurately without being disturbed by the magnetic field.

[0047] The present invention significantly shortens the length of the wires connected to the battery cells for impedance measurement by directly installing the impedance measurement board in the charging and discharging jig for impedance measurement of the battery cells, and Figure 1 The wire is extended as shown in (b) to eliminate the influence of the magnetic field.

[0048] Specific details regarding the charging and discharging jig for impedance measurement of the battery cell 10 of the present invention will be described with reference to exemplary embodiments and drawings.

[0049] Mode for the Invention

[0050] First Exemplary Embodiment

[0051] Figure 2 A first exemplary embodiment of a charging and discharging jig 1000 of the present invention for impedance measurement of a battery cell 10 is shown.

[0052] refer to Figure 2, the charging and discharging jig for impedance measurement of a battery cell 10 of the present invention includes: a jig body 100, on which the battery cell 10 is mounted in a longitudinal direction; a first bus bar 200 and a second bus bar 300, which are arranged on both sides of the jig body 100, and lead portions 11 and 12 at both ends of the battery cell 10 are respectively connected to the first bus bar 200 and the second bus bar 300; an impedance measurement board 400, which is arranged in the jig body 100; and a wire L for impedance measurement, which connects the first bus bar 200, the impedance measurement board 400, and the second bus bar 300 to constitute an impedance measurement circuit, and has a portion that faces a wide surface of the battery cell and extends in the longitudinal direction of the battery cell 10.

[0053] The battery cell 10 is mounted in the jig body 100 in the longitudinal direction, that is, such that the electrode leads at both ends are placed on both sides of the jig body 100. Figure 2 In the embodiment, the clamp body 100 is in the form of a fixed clamp whose length does not change. However, as will be described below, the clamp body 100 may be configured in the form of a variable clamp whose length can be adjusted in the longitudinal direction according to the length of the battery cell.

[0054] First, to measure the impedance of the battery cell 10, the battery cell 10 is positioned on the jig body 100, and the first and second bus bars on both sides of the charging and discharging jig are connected to the lead portions 11 and 12 of the battery cell 10. The first and second bus bars are each connected to the impedance measurement board 400 via a wire L for impedance measurement.

[0055] The impedance measurement board 400 of the present invention corresponds to a conventional impedance measurement device and, by significantly simplifying the detailed construction of a complex impedance measurement device, is constructed in the form of a small substrate required for impedance measurement. Therefore, by being constructed as a small substrate, the impedance measurement board can be easily introduced into the temperature chamber when measuring impedance in the temperature chamber. In particular, in the present invention, the impedance measurement board is mounted within the fixture body. As a result, the length of the impedance measurement wires, which comprise the leads at both ends of the battery cell and the impedance measurement board, is significantly shortened. In other words, because the impedance measurement unit is mounted within the charging and discharging fixture, there is no need to extend the wires to a certain length outside, as is conventionally done.

[0056] Specifically, the impedance measurement board 400 of the present invention includes: an AC signal source S configured to transmit an AC signal to the battery cell 10; a voltmeter V configured to measure a voltage difference between both ends of the battery cell 10; and an ammeter A configured to measure current.

[0057] Figure 3 The diagram shows a circuit for sensing the voltage applied to both ends of the lead portions 11 and 12 of the battery cell 10 using a four-terminal method. Referring to the diagram, it can be seen that a wire L connected to an AC signal source S and a voltmeter V is connected to both ends of the battery cell 10. The wire L for impedance measurement is composed of a signal line L1 configured to apply an AC signal to the battery cell and a sensing line L2 configured to measure the voltage of the battery cell. Figure 3 In the embodiment, the signal line L1 and the sensing line L2 are connected to the battery cell. By applying an AC signal from an AC signal source S, an AC current is applied to the battery cell 10 through the signal line L1. Because the battery cell 10 contains a predetermined impedance component, a potential difference (voltage) is generated at both ends of the lead portions 11 and 12 of the battery cell 10 by applying an AC current. At this time, the current moving through the wire L is measured by the ammeter A, and the voltage difference between the two ends of the battery cell 10 can be measured by the voltmeter V. The impedance of the battery cell 10 can be measured by the measured values ​​of the ammeter A and the voltmeter V. The ammeter A and the voltmeter V provided in the impedance measurement board 400 are connected to an external computing device or a display device so that the current and voltage can be visually expressed. The computing device can calculate the impedance of the battery cell 10 by dividing the voltage value by the AC current value, and the calculated impedance value can be displayed on the display device.

[0058] Come back for reference Figure 2 As can be seen, the first busbar 200 and the second busbar 300 connected to the lead portions 11 and 12 of the battery cell 10 are connected to the impedance measurement board 400 via a signal line L1 and a sensing line L2. The signal line L1 and the sensing line L2 can be connected to the first busbar and the second busbar, respectively, via a coupling member C or the like. The coupling member C can be a screw member for coupling the signal line and the sensing line to the busbars, but is not limited thereto. The signal line L1 is connected to the AC signal source S and the ammeter A of the impedance measurement board 400, and the sensing line L2 is connected to the voltmeter V of the impedance measurement board 400. The AC signal source S and the ammeter A of the impedance measurement board 400 are connected to the second busbar 300 via the signal line L1, and the voltmeter V is connected to the second busbar 300 via the sensing line L2.

[0059] The wire L for impedance measurement of the present invention preferably forms a loop connecting the first bus bar 200, the impedance measurement board 400, and the second bus bar 300. Figure 2 , it can be seen that the wire L extends from the first bus bar 200 to the second bus bar 300 across the impedance measurement board 400, and a portion of the wire L (signal line: L1 and sensing line: L2) constituting a loop extends in the longitudinal direction of the battery cell 10 along the bottom surface of the fixture body 100.

[0060] Meanwhile, the charging and discharging jig of the present invention includes first and second bus bars 200 and 300 coupled to the lead parts 11 and 12 at both ends of the battery cell 10. Figure 2 , the first bus bar and the second bus bar are inserted into and positioned in the bus bar coupling frames 230 and 330 , in which installation holes are formed so that the bus bars can be inserted therein.

[0061] The first and second bus bars are composed of upper bus bars 210 and 310 and lower bus bars 220 and 320 located below the upper bus bars 210 and 310, respectively, and the wire L for impedance measurement is connected to the upper bus bars 210 and 310 or the lower bus bars 220 and 320. Although not shown, when the wire L for impedance measurement is connected to the upper bus bars 210 and 310, the lower bus bars 220 and 320 are separately connected to a charging and discharging device configured to charge and discharge the battery cells 10 through the wire L.

[0062] The upper busbars 210 and 310 or the lower busbars 220 and 320 of the first busbar 200 and the second busbar 300 can each be separated into two busbars. More preferably, the busbar connected to the wire L for impedance measurement in the upper busbars 210 and 310 and the lower busbars 220 and 320 can be further separated into two busbars. As described above, since the present invention uses the four-terminal method to measure impedance, the upper busbar or the lower busbar is divided into two pieces, so that multiple wires can be connected to each of the separated busbars.

[0063] exist Figure 2 In the exemplary embodiment, the upper bus bars 210 and 310 of the first and second bus bars 200 and 300 are each separated into two bus bars, and the signal line L1 and the sensing line L2 are connected to each of the separated bus bars.

[0064] At the same time, insulators 250 and 350 are installed between the upper bus bars 210 and 310 and the bus bar coupling frames 230 and 330, and the insulators 250 and 350 are coupled to the upper portions of the upper bus bars. Adjustment screw portions 231 and 331 on the bus bar coupling frames 230 and 330 pass through the bus bar coupling frames 230 and 330 and are screwed to the insulators 250 and 350. Therefore, when the adjustment screw portions 231 and 331 are rotated, the insulators 250 and 350 and the upper bus bars 210 and 310 are raised and lowered, and accordingly, the lead portions 11 and 12 of the battery cells 10 can be easily inserted and removed between the upper bus bars 210 and 310 and the lower bus bars 220 and 320.

[0065] The bus bar connecting frames 230 and 330 are fixed to both sides of the clamp body 100, and the bus bar connecting frames 230 and 330 are configured to fix the first bus bar and the second bus bar and the insulators 250 and 350, and at this time, the bus bar supporting members 240 and 340 can be further interposed between the bus bar connecting frames 230 and 330 and the clamp body 100 as needed to adjust the height of the bus bar and support the bus bar connecting frames 230 and 330.

[0066] The clamp body 100 of the present invention may further include bases 260 and 360 installed at both sides of the lower portion of the clamp body 100. The bases 260 and 360 are coupled to the clamp body 100 and serve to stably support the clamp body 100.

[0067] Another characteristic point of the present invention is that the impedance measurement board 400 is installed close to the jig body 100, so that the length of the wire L can be reduced as much as possible. The impedance measurement board 400 can be installed at the lower part of the jig body 100, or as in Figure 2 , is installed in the lower part of the fixture body. According to one exemplary embodiment, the impedance measurement plate 400 is installed on the bases 260 and 360, or is installed in the lower part of the fixture body 100 adjacent to the bases 260 and 360. In this case, the impedance measurement plate 400 can be screwed to the bases 260 and 360 or the lower part of the fixture body 100, or can be adhesively connected. However, the present invention is not limited to this, and the impedance measurement plate 400 can be installed in a desired position using any means capable of fixing the impedance measurement plate 400. According to another exemplary embodiment, the impedance measurement plate 400 can be installed on a support 410 for the impedance measurement plate 400 that can support the impedance measurement plate 400, and in this case, the support 410 for the impedance measurement plate 400 can preferably be connected to the bases 260 and 360 included on both sides of the lower part of the fixture body 100.

[0068] Figure 4 yes Figure 2 Bottom view of the charge and discharge fixture for impedance measurement.

[0069] As in Figure 4 As shown in , a support member 500 for the wire L can be installed on the bottom surface of the fixture body 100 of the present invention, and the support member 500 for the wire L is configured to support the wire extending in the longitudinal direction of the battery cell 10 along the bottom surface of the fixture body 100. The support member 500 for the wire L is perforated from one side to the other, and the wire L is suspended through the perforation. At this time, the size of the perforation should be larger than the thickness of the wire L, and the movement of the wire L in the longitudinal direction of the battery cell 10 should not be interfered with by the support member 500 for the wire L. The wire L is reliably supported by the charging and discharging fixture through the wire support member 500 to prevent changes in the wire tension. That is, because the wire is stably supported by the wire support member and therefore the length of the wire does not change, the accuracy of the impedance measurement can be improved.

[0070] Figure 5 is a bottom view of a charging and discharging jig for impedance measurement of a battery cell according to another exemplary embodiment of the present invention.

[0071] On the bottom surface of the clamp body 100 of the present invention, as in Figure 5 As shown in , a fixing fixture 600 can be installed, which is configured to fix both sides of the wire L extending in the longitudinal direction of the battery cell 10 along the bottom surface of the fixture body 100. The fixing fixture 600 includes a shape in which the wire L can be inserted, and unlike the support member, the wire L inserted into the fixing fixture 600 is restricted from moving and is fixed. Impedance measurement can be easily performed by installing the fixing fixture 600 at the position where the wire L is to be fixed and fixing the wire L to the bottom of the fixture body 100 by inserting the wire L into the fixing fixture 600. Since the wire is fixedly connected to the charging and discharging fixture through the wire support member 500 and the fixing fixture without floating, the accuracy of the impedance measurement is improved.

[0072] Figure 6 is a bottom view of a charging and discharging jig for impedance measurement of a battery cell according to yet another exemplary embodiment of the present invention.

[0073] In this exemplary embodiment, the impedance measurement board 400 is installed in the middle of the bottom surface of the clamp body 100. In the present invention, because the impedance measurement board 400 is installed in the clamp body 100, the length of the wire used for impedance measurement is shortened as described above. In this case, the impedance measurement board 400 can be installed in the upper part, side part and lower part of the clamp body. However, when the impedance measurement board 400 is installed in the lower part of the clamp body 100, the impedance measurement board 400 may hinder the installation of the battery cell on the clamp, so it is preferable to install the impedance measurement board on the side or lower part of the clamp body. In addition, because the busbars are installed on both sides of the clamp body, it may be better to install the impedance measurement board in the lower part of the clamp body in consideration of the busbar installation space. When the impedance measurement board is installed in the lower part of the clamp body 100, the impedance measurement board may be installed as in Figure 2 As shown in FIG, it is installed on one side of the two sides of the clamp body 100. In addition, as shown in FIG. Figure 6 As shown in , the impedance measurement board can also be installed in the middle of the bottom surface of the jig body 100. It is important to measure impedance while shortening the length of the wire for impedance measurement by coupling the impedance measurement board to the line where the wire for impedance measurement extends.

[0074] Since the impedance measurement board 400 is installed in the middle of the jig body 100, a portion of the wire L forming a loop is pulled out to both sides of the impedance measurement board 400 and extends toward each of the first bus bar 200 and the second bus bar 300. At this time, even if the wire L is pulled out to both sides of the impedance measurement board 400, the magnetic field cancellation effect can still be maintained because the wire L is still in a position facing the wide surface of the battery cell 10.

[0075] Second Exemplary Embodiment

[0076] Figure 7 is a perspective view of a charging and discharging jig for impedance measurement of a battery cell according to another exemplary embodiment of the present invention.

[0077] This exemplary embodiment is in the form of a variable fixture in which the charging and discharging fixtures for impedance measurement can be displaced in the longitudinal direction. By changing the length of the fixture, there is an advantage that the fixture length can be adjusted to match different types of battery cells.

[0078] refer to Figure 7 , the fixture body 100 includes a fixed block 110 and a movable block 120 slidably coupled to the fixed block 110 , the first bus bar 200 is installed at one side of the fixed block 110 , and the second bus bar 300 is installed at one side of the movable block 120 .

[0079] According to the second exemplary embodiment, the clamp body 100 of the present invention is capable of variably deforming to measure impedance according to the length of the battery cell 10. Specifically, the clamp body 100 includes a fixed block 110 and a movable block 120, which slides in the longitudinal direction of the battery cell 10 relative to the fixed block 110. Of the wires L used at this time, the wires L extending along the bottom surface of the clamp body 100 should be installed assuming that the fixed block 110 and the movable block 120 are as far apart as possible so that the clamp body 100 can be deformed freely. The movable block 120 can be slidably connected to either the bottom surface or the upper surface of the fixed block 110. However, in this case, between the two blocks, it is preferred that the impedance measurement plate 400 is installed on the bottom surface of the block positioned lower than the other block. When the movable block 120 is as in Figure 7 When being slidably coupled to the upper surface of the fixed block 110 as shown in , the impedance measurement board 400 is mounted on the lower surface of the fixed block 110 positioned relatively lower. The coupling achieved by sliding of the movable block 120 and the fixed block 110 can be performed by coupling the guide slit 140 and the sliding support member 130. For example, the guide slit 140 may be formed on both sides in the width direction of one of the fixed block 110 and the movable block 120, and the sliding support member 130 inserted into the guide slit may be mounted on the other of the fixed block 110 and the movable block 120. Since the sliding support member 130 slides along the guide slit 140, the movable block 120 can slide along the fixed block 110. At this time, the guide slit 140 may be mounted in either one of the fixed block 110 and the movable block 120. Figure 7 In an exemplary embodiment, guide slits 140 are formed on both sides of the movable block 120 in the width direction, and sliding support members 130 are formed on both sides of the fixed block 110 in the width direction. Each sliding support member 130 may include a body portion that is inserted into the guide slits 140 and screwed to the fixed block 110 or the movable block 120, and a head portion that has a width greater than the width of the guide slits. Because the head portion has a width greater than the width of the guide slits 140, it is possible to prevent the sliding support member 130 from separating from the guide slits 140, and thus prevent the movable block 120 from separating from the fixed block 110. In addition, because the body portion of the sliding support member 130 has threads and is screwed to the fixed block 110 or the movable block 120, the movable block 120 can be fixed to the fixed block 110 by adjusting the degree of screwing. That is, after completing the movement of the movable block 120 , when the slide support member 130 is further rotated to move the head downward, the head presses the edges of both sides of the guide slit 140 , so that the movable block 120 can be fixed to the fixed block 110 .

[0080] Figure 8 yes Figure 7 Bottom view of the charge and discharge fixture for impedance measurement.

[0081] Figure 8 The following exemplary embodiment is shown: a support member 500 for a wire L is applied to a charging and discharging fixture for impedance measurement of a battery cell 10 of a second exemplary embodiment. In order to maintain the effect of offsetting the magnetic field generated in the battery cell 10, the wire L of the present invention should deviate as little as possible from the wide surface range of the battery cell 10. When the movable block 120 slides on the fixed block 110 and the deformation of the wire L increases, the support member 500 for the wire L is installed at an appropriate position, thereby minimizing the deformation of the wire L. However, it is necessary to avoid installing the support member 500 for the wire L on the sliding path so that the sliding of the movable block 120 is not interfered with by the support member 500 for the wire L. As shown in Figure 8 As shown in , by installing a support member 500 in the middle and on one side of the jig, and installing an impedance measurement board on the other side to connect the wire, the wire can be maintained in the jig without sagging. In addition, when the movable block moves, the wire may inevitably sag downward, but because the wire is supported by a plurality of support members 500, the degree of sagging can be reduced. Also in this exemplary embodiment, because a portion of the wire extends in the longitudinal direction of the battery cell, as shown in Figure 1 As shown in (b), the magnetic field caused by the current flowing in the battery cell can be offset by the magnetic field caused by the wire.

[0082] The present invention has been described in more detail above through drawings and exemplary embodiments. However, since the configuration depicted in the drawings or the exemplary embodiments described in this specification are merely exemplary embodiments of the present invention and do not represent all of the technical concepts of the present invention, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0083] Description of Reference Numerals

[0084] 10: Battery cells

[0085] 11, 12: Lead part L: Wire

[0086] 100: fixture body L1: signal line

[0087] 110: Fixed block L2: Sensing line

[0088] 120: Movable block A: Ammeter

[0089] 130: Sliding support member V: Voltmeter

[0090] 140: Guide slit S: AC signal source

[0091] 200: First bus bar R wire : Wire resistance

[0092] 300: Second bus bar

[0093] 210, 310: Upper bus bar C: Connecting member

[0094] 220, 320: lower busbar

[0095] 230, 330: Busbar connection frame

[0096] 231, 331: Adjustment thread

[0097] 240, 340: Busbar support members

[0098] 250, 350: insulator

[0099] 260, 360: base

[0100] 400: Impedance measurement board

[0101] 410: Support for impedance measurement board

[0102] 500: Support member for conductors

[0103] 600: Fixing fixture

Claims

1. A charging and discharging fixture for impedance measurement of a battery cell, the charging and discharging fixture comprising: a fixture body on which the battery cell is mounted in a longitudinal direction; a first bus bar and a second bus bar, the first bus bar and the second bus bar being installed on both sides of the jig body and the lead portions at both ends of the battery cell being respectively coupled to the first bus bar and the second bus bar; an impedance measurement board, the impedance measurement board being installed in the fixture body; and a conductor for impedance measurement, the conductor for impedance measurement connecting the first bus bar, the impedance measurement board, and the second bus bar to form an impedance measurement circuit; Part of the lead wire for impedance measurement has a portion facing a wide surface of the battery cell and extending in the longitudinal direction of the battery cell.

2. The charging and discharging jig according to claim 1, wherein The conductive line for impedance measurement includes a signal line configured to apply an AC signal to the battery cell and a sensing line configured to measure a voltage of the battery cell.

3. The charging and discharging jig according to claim 2, wherein The first bus bar and the second bus bar are each configured as an upper bus bar and a lower bus bar, and the lead wire for impedance measurement is connected to the upper bus bar or the lower bus bar.

4. The charging and discharging jig according to claim 3, wherein The upper bus bar of the first bus bar and the second bus bar is each separated into two bus bars, and the signal line and the sensing line are connected to each of the separated bus bars.

5. The charging and discharging jig according to claim 2, wherein The impedance measurement board includes an AC signal source and an ammeter connected to the signal line; and a voltmeter connected to the sensing line.

6. The charging and discharging jig according to claim 1, wherein The impedance measurement board is installed at the lower part of the fixture body. The impedance measurement wire forms a loop connecting the first bus bar, the impedance measurement board, and the second bus bar, and A portion of the conductive wire constituting the loop extends in the longitudinal direction of the battery cell along a bottom surface of the jig body.

7. The charging and discharging jig according to claim 6, further comprising a base provided on both sides of the lower portion of the jig body, wherein The impedance measurement board is installed on the base or a lower portion of the jig body adjacent to the base.

8. The charging and discharging jig according to claim 6, further comprising a base provided on both sides of the lower portion of the jig body, wherein The impedance measurement board is mounted on a measurement board support coupled to the base.

9. The charging and discharging jig according to claim 6, wherein A wire support member is installed on the bottom surface of the jig body, the wire support member being configured to support the wire for impedance measurement extending along the bottom surface of the jig body in the longitudinal direction of the battery cell.

10. The charging and discharging jig according to claim 6, wherein Fixing jigs are installed at both sides of the bottom surface of the jig body, the fixing jigs being configured to fix both sides of a wire extending in the longitudinal direction of the battery cell along the bottom surface of the jig body.

11. The charging and discharging jig according to claim 6, wherein The impedance measurement board is installed in the middle of the bottom surface of the jig body, and The portion of the conductive wire constituting the loop is pulled out to both sides of the impedance measurement board and extends toward each of the first bus bar and the second bus bar.

12. The charging and discharging jig according to claim 1, wherein The clamp body includes a fixed block and a movable block, the movable block being slidably coupled to the fixed block, and The first bus bar is installed at one side of the fixed block, and the second bus bar is installed at one side of the movable block.

13. The charging and discharging jig according to claim 12, wherein The movable block is slidably coupled to an upper surface of the fixed block.

14. The charging and discharging jig according to claim 13, wherein Guide slits are formed on both sides of one of the fixed block and the movable block in the width direction, and A sliding support member is mounted on the other of the fixed block and the movable block, the sliding support member being inserted into the guide slit.

15. The charging and discharging jig according to claim 14, wherein Each of the sliding support members has: a body portion inserted into the guide slit and screwed to the fixed block or the movable block; and a head portion having a width greater than a width of the guide slit.

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