Battery thermal runaway test jig

Abstract

The thermal runaway test jig for a battery according to the present invention includes a nail assembly having a nail at a lower portion thereof, and a nail holder for accommodating the nail assembly. The thermal runaway test jig for a battery according to the present invention has the effect of improving accuracy and safety in safety evaluation of a battery module.

Description

[Technical Field]

[0001] The present invention relates to a thermal runaway test jig for batteries, and more particularly to a cell bottom nail destruction test jig for battery modules. [Background technology]

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged. They are used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs), which are powered by electrical sources.

[0003] Currently widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of such unit secondary battery cells, i.e., unit battery cells, is approximately 2.5V to 4.6V. Therefore, when a higher output voltage is required, a battery pack is constructed by connecting multiple battery cells in series. Alternatively, a battery pack may be constructed by connecting multiple battery cells in parallel depending on the required charge / discharge capacity of the battery pack. Therefore, the number of battery cells included in the battery pack can be variously set depending on the required output voltage or charge / discharge capacity.

[0004] When a battery pack is constructed by connecting a plurality of battery cells in series / parallel, a common method is to first construct a battery module including at least one battery cell, preferably a plurality of battery cells, and then use at least one such battery module to construct the battery pack by adding other components. Here, the battery module refers to a component in which a plurality of battery cells are connected in series or parallel, and the battery pack refers to a component in which a plurality of battery modules are connected in series or parallel to increase capacity, output, etc.

[0005] However, when such battery modules and packs are overcharged, the battery modules may swell, causing explosions or fires, which can pose a greater risk to human life.

[0006] Therefore, a safety evaluation of the battery module or pack is always required. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal runaway test jig for batteries that can improve accuracy in evaluating the safety of battery modules. [Means for solving the problem]

[0008] A thermal runaway test jig for a battery according to an embodiment of the present invention includes a nail assembly having a nail at a lower portion thereof, and a nail holder for receiving the nail assembly.

[0009] The nail is also removably coupled to the nail assembly.

[0010] The nail assembly also includes a coupling groove into which the nail is coupled.

[0011] The nail assembly also includes a plurality of the nails.

[0012] The nail assembly also includes a push bar.

[0013] The nail assembly further includes an upper coupling groove to which the push bar is coupled.

[0014] The nail holder also includes an insertion groove into which the nail assembly is inserted.

[0015] The nail assembly is disposed in the insertion groove so as to be movable up and down.

[0016] The bottom of the insertion groove is spaced apart from the lower end of the nail holder.

[0017] The nail holder further includes a through hole below the insertion groove through which the nail passes.

[0018] The through hole extends from the bottom of the insertion groove to the lower end of the nail holder.

[0019] In addition, a plurality of through holes through which the plurality of nails pass are arranged in the lower part of the nail holder.

[0020] The nail holder further includes a pair of upper protrusions protruding upward from an upper portion thereof. [Effects of the Invention]

[0021] The thermal runaway test jig for batteries according to the present invention has the effect of improving accuracy and safety in safety evaluation of battery modules. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 shows a thermal runaway test box used in the present invention. [Figure 2] 2 is a diagram showing the inside of the thermal runaway test box shown in FIG. 1. [Figure 3] FIG. 2 is a longitudinal sectional view of the thermal runaway test box shown in FIG. [Figure 4] FIG. 2 is a cross-sectional perspective view of a cylindrical battery cell. [Figure 5] 1 is a diagram showing a state in which a thermal runaway test jig according to the present invention is installed in a thermal runaway test box. [Figure 6] 1 is a vertical cross-sectional view showing a state in which a thermal runaway test jig according to the present invention is installed in a thermal runaway test box. [Figure 7]1 is a perspective view of a thermal runaway test jig for a battery according to the present invention. [Figure 8] FIG. 8 is a longitudinal sectional view of the battery thermal runaway test jig shown in FIG. 7. [Figure 9] FIG. 8 is a partial detailed view of the battery thermal runaway test jig shown in FIG. 7. [Figure 10] FIG. 8 is a diagram showing the inside of the battery thermal runaway test jig shown in FIG. 7. [Figure 11] 1 is a diagram showing the state in which the thermal runaway test jig for batteries according to the present invention is used in a thermal runaway test box. DETAILED DESCRIPTION OF THE INVENTION

[0023] The advantages and features of the present invention, as well as methods for achieving the same, will become more apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. However, these embodiments are provided to fully disclose the present invention and to fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the claims. Therefore, in some embodiments, well-known process steps, well-known device structures, and well-known techniques will not be described in detail to avoid ambiguity. The same reference numerals refer to the same elements throughout the specification.

[0024] In the drawings, thicknesses of various layers and regions may be exaggerated to clearly show them. Similar parts are designated by the same reference numerals throughout the specification. When a layer, film, region, plate, or other part is said to be "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there are other parts between them. Conversely, when a part is said to be "directly on" another part, it means that there are no other parts between them. Furthermore, when a part is said to be "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there are other parts between them. Conversely, when a part is said to be "directly under" the other part, it means that there are no other parts between them.

[0025] Before describing the thermal runaway test jig 1000 for batteries according to the present invention, a multi-cell stacked thermal runaway test box 10 for thermal runaway testing will be described with reference to FIGS. 1 to 5. FIG.

[0026] FIG. 1 is a diagram showing a thermal runaway test box used in the present invention, FIG. 2 is a diagram showing the interior of the thermal runaway test box shown in FIG. 1, FIG. 3 is a vertical cross-sectional view of the thermal runaway test box shown in FIG. 1, FIG. 4 is a cross-sectional perspective view of a cylindrical battery cell, and FIG. 5 is a diagram showing a thermal runaway test jig according to the present invention installed inside the thermal runaway test box.

[0027] The safety evaluation of multi-cell modules (thermal propagation - chain fire) can be performed by subjecting some of the cells to external shock / energy, and then verifying the results. Multi-cell module safety evaluation is typically performed using a nail test, overcharge test, or heater test.

[0028] Of these, the Neel test can be performed on the bottom part (venting direction) of the cell due to the module structure.

[0029] The battery thermal runaway test jig 1000 according to the present invention can be used for Neel testing.

[0030] The thermal runaway test box 10 can include a plurality of battery cells 100 , a case 200 , and an intermediate frame 300 .

[0031] The battery cell 100 may be a cylindrical battery cell 100 in which the electrode assembly is housed in a metal can. FIG. 4 is a cross-sectional perspective view of the cylindrical battery cell 100.

[0032] The cylindrical battery cell 100 may include a jelly-roll-type electrode assembly 110 and a battery case 120 for accommodating the electrode assembly 110, and an upper insulating member 150 may be disposed on the upper end of the electrode assembly 110, and a lower insulating member 160 may be disposed on the lower end of the electrode assembly 110.

[0033] The electrode assembly 110 has a jelly-roll structure in which a positive electrode 111, a negative electrode 113, and a separator 112 interposed therebetween are wound up, and a center pin 140 can be inserted into the center thereof.

[0034] The cylindrical battery cell 100 can be formed by housing the electrode assembly 110 in a battery case 120, injecting an electrolyte into the battery case 120, and then attaching a cap assembly 130 to the upper end of the battery case 120. The battery case 120 is cylindrical, and housing the jelly-roll type electrode assembly 110 in the cylindrical battery case 120 can implement a cylindrical secondary battery.

[0035] The battery case 120 may include a bottom portion 121 disposed on the bottom, a beading portion 122, and a clamping portion 123.

[0036] The beading portion 122 is for stable connection of the cap assembly 130 and may be formed along the circumferential direction on the upper portion of the outer periphery of the battery case 120 and may be recessed from the outer periphery of the battery case 120 toward the center of the electrode assembly 110. The beading portion 122 may prevent the electrode assembly 110 from moving loosely.

[0037] The clamping portion 123 may be disposed on the beading portion 122 and may be formed to surround the edge of the cap assembly 130 in a circumferential direction. The clamping portion 123 may facilitate stable coupling of the cap assembly 130.

[0038] The cap assembly 130 may include an upper cap 131 that forms a positive electrode terminal, a cap plate 132 to which a positive electrode tab 134 extending upward from the electrode assembly 110 is connected, and a gasket 133 for maintaining airtightness.

[0039] The gasket 133 is attached to the upper inner surface of the clamping portion 123 and the beading portion 122 to increase the sealing force between the cap assembly 130 and the battery case 120 .

[0040] As previously mentioned, the positive electrode tab 134 may extend upward from the electrode assembly 110. Specifically, it may extend from the positive electrode 111 of the electrode assembly 110.

[0041] The positive electrode tab 134 is connected to the cap plate 132, so that the upper cap 131 can function as a positive electrode terminal. An opening 151 is formed in the upper insulating member 150, and the positive electrode tab 134 can pass through the opening 151 and be connected to the cap plate 132.

[0042] The center pin 140 is generally made of a metal material and has a cylindrical structure formed by bending a plate material into a round shape to provide a predetermined strength. In addition to self-heating, the center pin 140 can also fix and support the electrode assembly 110 and function as a passage for releasing gas generated by internal reactions during charge / discharge and operation.

[0043] The electrolyte solution injected into the battery case 120 is a lithium salt-containing non-aqueous electrolyte solution, which is composed of a non-aqueous electrolyte solution and a lithium salt. Examples of the non-aqueous electrolyte solution include, but are not limited to, a non-aqueous organic solvent, an organic solid electrolyte, and an inorganic solid electrolyte.

[0044] The battery cells 100 applied to the thermal runaway test box 10 do not necessarily have to be limited to cylindrical battery cells 100. For example, the thermal runaway test box 10 according to the present invention can also be constructed using can-type battery cells in which the shape of the battery case 120 is not cylindrical but is rectangular or has other shapes.

[0045] The case 200 of the thermal runaway test box 10 can accommodate a plurality of battery cells 100. In this embodiment, the case 200 may have a rectangular parallelepiped shape as shown. An insertion hole 211 may be formed in an upper plate 210 of the case 200.

[0046] In this embodiment, a structure in which a plurality of battery cells 100 are stacked vertically inside the case 200 may be adopted.

[0047] Regarding the structure in which the battery cell 100 is disposed at the top inside the case 200 , the battery cell 100 may be disposed between a cell bottom frame 250 and a cell top frame 270 .

[0048] The cell bottom frame 250 may include a plurality of substantially rectangular cell insertion openings 251, into which the battery cells 100 may be inserted one by one. The cell insertion openings 251 may be circular, into which the circular battery cells 100 may be inserted. For example, as shown in FIGS. 5 and 6 , the battery cells 100 may be inserted and arranged in each cell insertion opening 251 such that the top end cap 131 faces upward and the bottom 121 of the battery case 120 faces downward.

[0049] When the battery cells 100 are inserted into the cell bottom frame 250 , the battery cells 100 may be configured to be arranged in multiple rows in the X-axis or Y-axis direction of the case 200 .

[0050] The cell top frame 270 may be disposed on the top of the battery cell 100 to cover the upper region of the battery cell, and may be configured to be coupled to the cell bottom frame 250 .

[0051] For example, the cell top frame 270 may be provided with a cell socket 271 that matches the cell insertion opening 251 of the cell bottom frame 250 vertically, and when the cell top frame 270 and the cell bottom frame 250 are combined, the upper end cap 131 of the battery cell 100 is inserted into the cell socket 271, so that the upper region of the battery cell 100 is covered by the cell top frame 270.

[0052] Furthermore, a large number of holes 272 are arranged on the upper surface of the cell top frame 270, as shown in FIG.

[0053] The hole 272 formed on the upper surface of the cell top frame 270 may be configured by partially perforating the cell top frame 21 so that the upper end cap 131 of the battery cell 100 or the upper end of the battery case 120 is partially exposed to the outside.

[0054] Such holes 272 can be used as passages that enable the battery cells 100 to be connected to bus bars 400 disposed on the upper surface of the cell top frame 270 by metal wires.

[0055] The bus bar 400 may be connected to the upper end cap 131 of the battery cell 100 or the upper end of the battery case 120 exposed through the hole 272 by a metal wire. For example, a wire bonding method may be used in which one end of the metal wire is welded to the upper end cap 131 or the upper end of the battery case 120 and the other end of the metal wire is welded to the bus bar 400.

[0056] In this embodiment, the structure in which the battery cells 100 are arranged at the bottom inside the case 200 may be configured as a structure in which the battery cells are arranged at the top are inverted or symmetrical.

[0057] In a structure in which the battery cells 100 are arranged at the bottom inside the case 200, the battery cells 100 may be arranged between the cell bottom frame 250 and the cell top frame 270, similar to the structure in which the battery cells 100 are arranged at the top described above, but the direction in which the battery cells 100 are arranged may be opposite to the structure in which the battery cells 100 are arranged at the top described above.

[0058] That is, the battery cells 100 may be arranged in the lower part of the case 200 with the top caps 131 facing downward and the bottom 121 of the battery case 120 facing upward. Therefore, the cell bottom frame 250 may be arranged on top of the bottom 121 of the battery case 120 in the lower part of the case 200, and the cell top frame 270 may be arranged on bottom of the top caps 131 of the battery cells 100. The battery cells 100 arranged in the lower part may be offset from the upper battery cells 100, and one upper battery cell 100 may be arranged over two battery cells 100 arranged in the lower part, as shown in FIG. 6 .

[0059] In a structure in which the battery cells 100 are arranged at the bottom inside the case 200, the cell bottom frame 250 may include multiple cell insertion openings 251, similar to the structure in which the battery cells 100 are arranged at the top, the cell top frame 270 may have cell sockets 271, and the holes 272 and bus bars 400 may be arranged in the same manner.

[0060] An intermediate frame 300 is disposed between the upper and lower battery cells 100 in the case 200, and the cell bottom frames 250 on which the upper and lower battery cells 100 are disposed may be disposed on the upper and lower sides of the intermediate frame 300 so as to face each other.

[0061] A battery thermal runaway test jig 1000 according to the present invention that is applied to the thermal runaway test box 10 having the above configuration will be described.

[0062] Figure 6 is a diagram showing a vertical cross-section of a thermal runaway test jig for batteries according to the present invention installed in a thermal runaway test box, Figure 7 is an oblique view of a thermal runaway test jig for batteries according to the present invention, Figure 8 is a vertical cross-sectional view of the thermal runaway test jig for batteries shown in Figure 7, Figure 9 is a detailed partial view of the thermal runaway test jig for batteries shown in Figure 7, Figure 10 is a diagram showing the inside of the thermal runaway test jig for batteries shown in Figure 7, and Figure 11 is a diagram showing the use of a thermal runaway test jig for batteries according to the present invention in a thermal runaway test box.

[0063] The thermal runaway test jig 1000 for a battery according to an embodiment of the present invention may include a nail assembly 1200 to which a nail 1210 is coupled, and a nail holder 1100 that supports the nail assembly 1200.

[0064] The nail assembly 1200 has one or more nails 1210 coupled to its lower portion, and for this purpose, a coupling groove 1220 to which the nail 1210 is coupled may be formed at the lower portion of the nail assembly 1200 .

[0065] A plurality of nails 1210 may be coupled to the nail assembly 1200, and a plurality of coupling grooves 1220 may be formed at the bottom of the nail assembly 1200 to which the plurality of nails 1210 may be coupled, respectively.

[0066] 6 to 11 show an example in which two coupling grooves 1220 are formed in the lower part of a nail assembly 1200, and nails 1210 are coupled to the two coupling grooves 1220, respectively.

[0067] An upper coupling groove 1230 is formed on the upper portion of the nail assembly 1200, and a push bar 1300 can be coupled to the upper coupling groove 1230.

[0068] The pusher bar 1300 is removably coupled to the top of the nail assembly 1200 so that the pusher bar 1300 can be replaced.

[0069] The push bar 1300 is configured so that the nail assembly 1200 can be moved downward by pushing the push bar 1300 outside the thermal runaway test box 10 .

[0070] As shown in the figure, the push bar 1300 can be disposed so as to extend outward through the insertion hole 211 of the upper plate 210 when the thermal runaway test jig 1000 of the present invention is attached to the thermal runaway test box 10. Thus, the push bar 1300 can be pushed outside the thermal runaway test box 10 to destroy the battery cells 100.

[0071] The nail 1210 is used to destroy the battery cell 100 and is disposed vertically at the bottom of the nail assembly 1200. The body of the nail 1210 extends vertically in a cylindrical shape, and the lower end of the nail 1210 may be formed to be pointed in a conical shape.

[0072] The nail 1210 is detachably coupled to a coupling groove 1220 formed at the bottom of the nail assembly 1200, making it possible to replace the nail 1210. The lower end of the nail 1210 is formed in a cone shape, making it easy to break the bottom of the battery cell 100.

[0073] The nail 1210 and nail assembly 1200 may be housed within a nail holder 1100 as shown.

[0074] The nail holder 1100 is for receiving and supporting the nail 1210 and the nail assembly 1200, and the body of the nail holder 1100 is substantially cylindrical in this embodiment.

[0075] Specifically, the nail holder 1100 includes an insertion groove 1110 into which the nail assembly 1200 is inserted.

[0076] The insertion groove 1110 extends downward from the upper end of the nail holder 1100 by a certain length, and the nail assembly 1200 to which the nail 1210 is coupled can move up and down within the insertion groove 1110 after being inserted into the insertion groove 1110. Therefore, the vertical length of the insertion groove 1110 may be longer than that of the nail assembly 1200.

[0077] The insertion groove 1110 may be formed to correspond to the nail assembly 1200. Therefore, the inner peripheral surface of the insertion groove 1110 may include a pair of first inner wall surfaces 1110a and a pair of second inner wall surfaces 1110b facing each other to correspond to the nail assembly 1200. The second inner wall surfaces 1110b may connect the pair of first inner wall surfaces 1110a to each other, and in this embodiment, the first inner wall surfaces 1110a may be configured as a flat surface, and the second inner wall surfaces 1110b may be formed to have a rounded, arc-shaped cross section.

[0078] A bottom 1111 of the insertion groove 1110 located at the lower end of the insertion groove 1110 is spaced apart from the lower end of the nail holder 1100 at a predetermined distance upward, and a through hole 1120 may be formed in the bottom of the insertion groove 1110 .

[0079] The through hole 1120 extends from the bottom 1111 of the insertion groove 1110 to the lower end of the nail holder 1100, and this through hole 1120 allows the bottom 1111 of the insertion groove 1110 to communicate with the outside.

[0080] Then, the nail 1210 can move downward from the nail holder 1100 through this through hole 1120 and destroy the battery cell 100.

[0081] A pair of upper protrusions 1130 may be formed on the upper portion of the nail holder 1100. The upper protrusions 1130 extend upward from the pair of first inner wall surfaces 1110a and are disposed on both sides of the nail assembly 1200, thereby guiding the insertion and vertical movement of the nail assembly 1200.

[0082] Furthermore, when the thermal runaway test jig 1000 according to the present invention is attached to the test box 10 , the tester can easily insert it into the cell insertion opening 251 of the test box 10 by holding the upper protrusion 1130 .

[0083] Next, a process of mounting the thermal runaway test jig 1000 for a battery according to the present invention in the test box 10 and performing a thermal propagation (TP) test will be described with reference to FIGS.

[0084] As shown in FIG. 6, a thermal runaway test jig 1000 is attached to one of the cell insertion holes 251 in the thermal runaway test box 10 instead of a battery cell 100, and the push bar 1300 is pressed downward with the push bar 1300 connected to the nail assembly 1200 through the insertion hole 211 formed in the upper plate 210 of the case 200 in the thermal runaway test box 10.

[0085] When the push bar 1300 is pushed downward, the nail assembly 1200 moves downward along the insertion groove 1110, and the downward movement of the nail assembly 1200 causes the nail 1210 to move downward through the through hole 1120. The nail assembly 1200 can move downward until it contacts the bottom 1111 of the insertion groove 1110.

[0086] As shown in FIG. 11, the battery cell 100 arranged on the lower side is arranged opposite to the battery cell 100 arranged on the upper side, and the battery cell 100 arranged on the lower side can be arranged so that the upper end cap 131 faces downward and the bottom 121 of the battery case 120 faces upward.

[0087] Therefore, the bottom of the battery cell 100 can be destroyed by the downward moving nail 1210.

[0088] Specifically, the nail 1210 can move downward through the upper cell bottom frame 250, the intermediate frame 300, and the lower cell bottom frame 250, and the end 1211 of the nail 1210 can penetrate the bottom of the battery cell 100 arranged below and enter the interior of the battery cell 100.

[0089] As shown in the figure, in this embodiment, two nails 1210 disposed at the bottom of the nail assembly 1200 can penetrate the bottoms of two adjacent battery cells 100, respectively.

[0090] As described above, in the present invention, the thermal runaway test jig 1000 is configured as described above, thereby improving the accuracy and safety of the thermal runaway test.

[0091] Specifically, the present invention allows accurate alignment of the battery cell 100 to be destroyed with the nail 1210, and allows destruction at an accurate position of the battery cell 100.

[0092] Furthermore, the present invention makes it possible to perform a thermal runaway (TP) test on multiple cells as well as a single cell without causing a test failure due to bending of the nail 1210.

[0093] As described above, the present invention has been described based on preferred embodiments, but it is not limited to the above embodiments, and various changes and modifications may be made by a person having ordinary skill in the art to which the present invention pertains without departing from the spirit of the present invention. [Industrial Applicability]

[0094] The present invention provides a thermal runaway test jig for batteries that can improve accuracy and safety in safety evaluation of battery modules.

Claims

1. a nail assembly including a nail at a lower portion; a nail holder for accommodating the nail assembly; Includes a thermal runaway test jig for batteries.

2. The battery thermal runaway test jig of claim 1 , wherein the nail is removably coupled to the nail assembly.

3. The thermal runaway test jig for batteries according to claim 1 , wherein the nail assembly includes a coupling groove to which the nail is coupled.

4. The thermal runaway test jig for batteries according to claim 1 , wherein the nail assembly includes a plurality of the nails.

5. The battery thermal runaway test jig of claim 1 , wherein the nail assembly further comprises a push bar.

6. The thermal runaway test jig for batteries according to claim 5 , wherein the nail assembly further includes an upper coupling groove to which the push bar is coupled.

7. The thermal runaway test jig for batteries according to claim 1 , wherein the nail holder includes an insertion groove into which the nail assembly is inserted.

8. The thermal runaway test jig for batteries according to claim 7 , wherein the nail assembly is arranged in the insertion groove so as to be movable up and down.

9. The thermal runaway test jig for a battery according to claim 7 , wherein a bottom of the insertion groove is spaced apart from a lower end of the nail holder.

10. The thermal runaway test jig for a battery according to claim 7 , wherein the nail holder further includes a through-hole below the insertion groove through which the nail passes.

11. The thermal runaway test jig for batteries according to claim 10 , wherein the through-hole extends from the bottom of the insertion groove to the lower end of the nail holder.

12. The thermal runaway test jig for a battery according to claim 10 , wherein a plurality of through holes through which a plurality of the nails pass respectively are arranged in a lower portion of the nail holder.

13. The thermal runaway test jig for batteries according to claim 7 , wherein the nail holder further includes a pair of upper protrusions protruding upward from an upper portion thereof.

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