Thermal runaway test jig for batteries

Abstract

A thermal runaway test jig for batteries, according to the present invention, comprises: a nail assembly which includes nails at the bottom thereof; and a nail holder which accommodates the nail assembly. The thermal runaway test jig for batteries, according to the present invention, has an advantage in that, in evaluating the stability of a battery module, accuracy and safety can be improved.

Description

Thermal runaway test jig for batteries

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

[0002] Secondary batteries, unlike primary batteries that cannot be recharged, 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) that are driven by electrical power 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 these unit secondary battery cells, i.e., unit battery cells, is approximately 2.5 V to 4.6 V. Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Furthermore, depending on the charge / discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Therefore, the number of battery cells included in the battery pack can be set in various ways depending on the required output voltage or charge / discharge capacity.

[0004] When configuring a battery pack by connecting multiple battery cells in series or parallel, it is common to first configure a battery module comprising at least one battery cell, preferably multiple battery cells, and then use at least one such battery module and add other components to configure the battery pack. Here, a battery module refers to a component in which multiple battery cells are connected in series or parallel, and a battery pack refers to a component in which multiple battery modules are connected in series or parallel to increase capacity and output.

[0005] However, in the case of overcharging, etc., in these battery modules and packs, swelling of the battery module may cause an explosion or fire, and such explosion or fire may cause greater danger, even leading to casualties.

[0006] Therefore, stability evaluation of battery modules or packs is essential.

[0007] The purpose of the present invention is to provide a thermal runaway test jig for a battery that can improve accuracy in evaluating the stability of a battery module.

[0008] A thermal runaway test jig for a battery according to one embodiment of the present invention is characterized by including: a nail assembly including a nail at the bottom; and a nail holder for accommodating the nail assembly.

[0009] Additionally, the nail is detachably connected to the nail assembly.

[0010] Additionally, the nail assembly includes a joining groove into which the nail is joined.

[0011] Additionally, the nail assembly includes a plurality of the nails.

[0012] Additionally, the nail assembly further includes a push bar.

[0013] Additionally, the nail assembly further includes an upper engaging groove to which the push bar is engaged.

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

[0015] Additionally, the nail assembly is positioned so as to be movable up and down within the insertion groove.

[0016] Additionally, the bottom of the insertion groove is positioned apart from the bottom of the nail holder.

[0017] Additionally, the nail holder further includes a through hole through which the nail passes at the lower side of the insertion groove.

[0018] Additionally, the passage hole extends from the bottom of the insertion groove to the bottom of the nail holder.

[0019] Additionally, a plurality of passage holes through which a plurality of nails pass are arranged at the bottom of the nail holder.

[0020] Additionally, the nail holder further includes a pair of upper projections protruding upwardly on the upper portion.

[0021] The thermal runaway test jig for a battery according to the present invention has the effect of improving accuracy and safety in evaluating the stability of a battery module.

[0022] Figure 1 is a drawing showing a thermal runaway test box used in the present invention.

[0023] Figure 2 is a drawing showing the inside of the thermal runaway test box illustrated in Figure 1.

[0024] Figure 3 is a longitudinal cross-sectional view of the thermal runaway test box illustrated in Figure 1.

[0025] Figure 4 is a cross-sectional perspective view of a cylindrical battery cell.

[0026] Figure 5 is a drawing showing a state in which a thermal runaway test jig according to the present invention is mounted in a thermal runaway test box.

[0027] Figure 6 is a cross-sectional view showing a thermal runaway test jig according to the present invention mounted in a thermal runaway test box.

[0028] Figure 7 is a perspective view of a thermal runaway test jig for a battery according to the present invention.

[0029] Figure 8 is a cross-sectional view of the thermal runaway test jig for the battery illustrated in Figure 7.

[0030] Fig. 9 is a detailed view of a portion of the thermal runaway test jig for a battery illustrated in Fig. 7.

[0031] Figure 10 is a drawing showing the inside of the thermal runaway test jig for the battery shown in Figure 7.

[0032] Figure 11 is a diagram showing the state of use of a thermal runaway test jig for a battery according to the present invention within a thermal runaway test box.

[0033] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Accordingly, in some embodiments, well-known process steps, well-known device structures, and well-known techniques are not specifically described to avoid ambiguity in the interpretation of the present invention. Like reference numerals refer to like elements throughout the specification.

[0034] In order to clearly represent multiple layers and regions in the drawings, the thickness may be enlarged. Similar parts are designated by the same drawing reference numerals throughout the specification. When an element such as a layer, film, region, or plate is said to be "over" another element, this includes not only the case where it is "directly over" that element but also the case where there are other elements in between. Conversely, when an element is said to be "directly over" another element, this means that there are no other elements in between. Furthermore, when an element such as a layer, film, region, or plate is said to be "under" another element, this includes not only the case where it is "directly under" that element but also the case where there are other elements in between. Conversely, when an element is said to be "directly under" another element, this means that there are no other elements in between.

[0035] Before explaining the thermal runaway test jig (1000) for a battery according to the present invention, a multi-cell stacked thermal runaway test box (10) for a thermal runaway test will be explained with reference to FIGS. 1 to 5.

[0036] FIG. 1 is a drawing illustrating a thermal runaway test box used in the present invention, FIG. 2 is a drawing illustrating the inside of the thermal runaway test box illustrated in FIG. 1, FIG. 3 is a longitudinal cross-sectional view of the thermal runaway test box illustrated in FIG. 1, FIG. 4 is a cross-sectional perspective view of a cylindrical battery cell, and FIG. 5 is a drawing illustrating a state in which a thermal runaway test jig according to the present invention is mounted within the thermal runaway test box.

[0037] The stability assessment of multi-cell modules (thermal propagation-chain ignition) can be verified by applying external shock / energy to some cells, destroying them, and then verifying the results. Multi-cell module stability assessments are typically conducted through nail tests, overcharge tests, and heater tests.

[0038] Among these, the nail test can be performed at the bottom part (venting direction) of the cell due to the structure of the module.

[0039] The thermal runaway test jig (1000) for a battery according to the present invention can be used for nail testing.

[0040] The thermal runaway test box (10) may include a plurality of battery cells (100), a case (200), and an intermediate frame (300).

[0041] The battery cell (100) may be a cylindrical battery cell (100) in which the electrode assembly is built into a metal can. Fig. 4 is a cross-sectional perspective view of a cylindrical battery cell (100).

[0042] A cylindrical battery cell (100) may include a jelly roll-shaped electrode assembly (110) and a battery case (120) for storing the electrode assembly (110). An upper insulating member (150) may be placed on the upper side of the electrode assembly (110), and a lower insulating member (160) may be placed on the lower side of the electrode assembly (110).

[0043] The electrode assembly (110) has a jelly roll-shaped structure in which a positive electrode (111), a negative electrode (113), and a separator (112) are interposed between them and wound, and a center pin (140) can be inserted into the center thereof.

[0044] A cylindrical battery cell (100) can be formed by housing an electrode assembly (110) in a battery case (120), injecting an electrolyte into the battery case (120), and then joining a cap assembly (130) to the top of the battery case (120). The battery case (120) is cylindrical, and a jelly roll-shaped electrode assembly (110) can be housed in the cylindrical battery case (120) to implement a cylindrical secondary battery.

[0045] The battery case (120) may include a bottom portion (121) placed on the floor, a beading portion (122), and a clamping portion (123).

[0046] The above beading portion (122) is for stable bonding of the cap assembly (130), and can be formed along the circumferential direction on the upper portion of the outer surface of the battery case (120), or can be formed by recessing in the center direction of the electrode assembly (110) on the outer surface of the battery case (120). The beading portion (122) can prevent movement of the electrode assembly (110).

[0047] The clamping portion (123) may be positioned on top of the beading portion (122) and formed to wrap around the edge portion of the cap assembly (130) along the circumferential direction. The clamping portion (123) may facilitate stable bonding of the cap assembly (130).

[0048] The cap assembly (130) may include a top cap (131) forming a positive terminal, a cap plate (132) to which a positive tab (134) extending upward from the electrode assembly (110) is connected, and a gasket (133) for maintaining confidentiality.

[0049] A gasket (133) can be mounted on 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).

[0050] As described above, 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).

[0051] These positive electrode tabs (134) are 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 tabs (134) can pass through the opening (151) and be connected to the cap plate (132).

[0052] The center pin (140) typically comprises a metal material to impart a certain strength and is formed into a cylindrical structure formed by bending a plate. 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 gases generated by internal reactions during charging, discharging, and operation.

[0053] The electrolyte injected into the battery case (120) may be a non-aqueous electrolyte containing a lithium salt, and the non-aqueous electrolyte containing a lithium salt is composed of a non-aqueous electrolyte and a lithium salt. Non-aqueous electrolytes include, but are not limited to, non-aqueous organic solvents, organic solid electrolytes, and inorganic solid electrolytes.

[0054] The battery cell (100) applied to the thermal runaway test box (10) is not necessarily limited to a cylindrical battery cell (100). For example, the thermal runaway test box (10) according to the present invention may be configured using a can-shaped battery cell having a shape other than a cylindrical shape of the battery case (120) or a rectangular parallelepiped shape.

[0055] The case (200) of the thermal runaway test box (10) can accommodate a plurality of battery cells (100), and in the present embodiment, the case (200) can be formed in a rectangular parallelepiped shape as shown. An insertion hole (211) can be formed in the upper plate (210) of the case (200).

[0056] In this embodiment, a structure in which multiple battery cells (100) are stacked vertically inside a case (200) may be formed.

[0057] When explaining the structure in which the battery cell (100) is placed at the top inside the case (200), the battery cell (100) can be placed between the cell bottom frame (250) and the cell top frame (270).

[0058] The cell bottom frame (250) may include a plurality of cell insertion holes (251) in a roughly square shape, and battery cells (100) may be inserted into each of the cell insertion holes (251). The cell insertion holes (251) may be formed in a circular shape, so that a circular battery cell (100) may be inserted therein. For example, as shown in FIGS. 5 and 6, the battery cells (100) may be inserted and arranged in each cell insertion hole (251) such that the top cap (131) faces upward and the bottom portion (121) of the battery case (120) faces downward.

[0059] When battery cells (100) are inserted into the cell bottom frame (250), the battery cells (100) can be configured to form multiple rows in the X-axis or Y-axis direction of the case (200).

[0060] The cell top frame (270) can be placed on top of the battery cell (100) to cover the upper area of ​​the battery cell, and can be configured to be mutually coupled with the cell bottom frame (250).

[0061] For example, the cell top frame (270) may be provided with cell sockets (271) that are aligned vertically with the cell insertion holes (251) of the cell bottom frame (250), and when the cell top frame (270) and the cell bottom frame (250) are combined, the upper caps (131) of the battery cells (100) may be inserted into the cell sockets (271) so that the upper areas of the battery cells (100) are covered by the cell top frame (270).

[0062] Additionally, a number of holes (272) are arranged on the upper surface of the cell top frame (270) as shown in FIG. 5.

[0063] The holes (272) formed on the upper surface of the cell top frame (270) may be configured to partially perforate the cell top frame (21) so that the upper cap (131) of the battery cells (100) or the upper end of the battery case (120) can be partially exposed to the outside.

[0064] These holes (272) can be used as passages to connect the battery cells (100) to the bus bars (400) arranged on the upper surface of the cell top frame (270) using metal wires.

[0065] The bus bar (400) can be connected to the upper cap (131) of the battery cell (100) or the upper end of the battery case (120) exposed through the holes (272) using a metal wire. For example, a wire bonding method can be employed in which one end of the metal wire is welded to the upper end of the upper cap (131) or the battery case (120) and the other end of the metal wire is welded to the bus bar (400).

[0066] In this embodiment, the structure in which the battery cell (100) is arranged at the bottom inside the case (200) may be configured as a structure that is flipped upside down or a structure that is symmetrical upside down compared to the structure in which the battery cell is arranged at the top.

[0067] The structure in which the battery cell (100) is arranged at the bottom inside the case (200) is similar to the structure in which the battery cell (100) is arranged at the top described above, in which the battery cell (100) may be arranged between the cell bottom frame (250) and the cell top frame (270), but the direction in which the battery cell (100) is arranged may be opposite to the structure in which the battery cell (100) is arranged at the top described above.

[0068] That is, the battery cell (100) may be arranged in the lower part of the case (200) such that the upper cap (131) faces downward and the bottom part (121) of the battery case (120) faces upward. Accordingly, the cell bottom frame (250) may be arranged on the upper part of the bottom part (121) of the battery case (120) in the lower part of the case (200), and the cell top frame (270) may be arranged under the top cap (131) of the battery cell (100). In addition, the battery cell (100) arranged in the lower part may be arranged to be misaligned with the upper battery cell (100), and as illustrated in FIG. 6, etc., one upper battery cell (100) may be arranged to span over two battery cells (100) arranged in the lower part.

[0069] In a structure in which battery cells (100) are arranged at the bottom inside a case (200), the cell bottom frame (250) may include a plurality of cell insertion holes (251) in the same manner as the upper battery cell (100) arrangement structure, and the cell top frame (270) may have cell sockets (271), and the holes (272) and bus bars (400) may also be arranged in the same manner.

[0070] An intermediate frame (300) may be placed between the upper and lower battery cells (100) in the case (200), and a cell bottom frame (250) in which the upper and lower battery cells (100) are placed on the upper and lower sides of the intermediate frame (300) may be placed so as to face each other.

[0071] A thermal runaway test jig (1000) for a battery according to the present invention applied to a thermal runaway test box (10) having such a configuration is described.

[0072] FIG. 6 is a cross-sectional view showing a thermal runaway test jig according to the present invention mounted in a thermal runaway test box, FIG. 7 is a perspective view of a thermal runaway test jig for a battery according to the present invention, FIG. 8 is a cross-sectional view of the thermal runaway test jig for a battery shown in FIG. 7, FIG. 9 is a partial detailed view of the thermal runaway test jig for a battery shown in FIG. 7, FIG. 10 is a view showing the inside of the thermal runaway test jig for a battery shown in FIG. 7, and FIG. 11 is a diagram showing the state of use of the thermal runaway test jig for a battery according to the present invention in a thermal runaway test box.

[0073] A thermal runaway test jig (1000) for a battery according to one 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).

[0074] The nail assembly (1200) above can have one or more nails (1210) coupled to the lower portion thereof, and for this purpose, a coupling groove (1220) into which the nails (1210) are coupled can be formed at the lower portion of the nail assembly (1200).

[0075] Additionally, a plurality of nails (1210) can be combined in the nail assembly (1200), and a plurality of combining grooves (1220) can be formed in the lower part of the nail assembly (1200) to which the plurality of nails (1210) are each combined.

[0076] FIGS. 6 to 11 illustrate examples in which two joining grooves (1220) are formed at the bottom of a nail assembly (1200), and nails (1210) are joined to each of the two joining grooves (1220).

[0077] An upper joining groove (1230) may be formed on the upper part of the nail assembly (1200), and a push bar (1300) may be joined to the upper joining groove (1230).

[0078] The push bar (1300) can be detachably attached to the upper part of the nail assembly (1200), and thus the push bar (1300) is replaceable.

[0079] The push bar (1300) can move the nail assembly (1200) downward by pressing the push bar (1300) from the outside of the thermal runaway test box (10).

[0080] As illustrated, the push bar (1300) can be positioned to extend outward through the insertion hole (211) of the upper plate (210) while the thermal runaway test jig (1000) of the present invention is mounted on the thermal runaway test box (10). As a result, the battery cell (100) can be destroyed by pressing the push bar (1300) from the outside of the thermal runaway test box (10).

[0081] The above nail (1210) is intended to destroy the battery cell (100), and can be vertically positioned at the bottom of the nail assembly (1200). The body of the nail (1210) extends up and down in a cylindrical shape, and the lower end of the nail (1210) can be formed into a pointed cone shape.

[0082] The nail (1210) is detachably connected to the connecting groove (1220) formed at the bottom of the nail assembly (1200), thereby enabling replacement of the nail (1210), and the lower part of the nail (1210) is formed in a cone shape, thereby making it easy to destroy the bottom of the battery cell (100).

[0083] The nail (1210) and nail assembly (1200) can be accommodated within the nail holder (1100) as illustrated.

[0084] The above nail holder (1100) is intended to accommodate and support a nail (1210) and a nail assembly (1200), and the body of the nail holder (1100) is formed in an approximately cylindrical shape in this embodiment.

[0085] Specifically, the nail holder (1100) includes an insertion groove (1110) into which a nail assembly (1200) is inserted.

[0086] The insertion groove (1110) is formed by extending downward from the top of the nail holder (1100) by a certain length, and the nail assembly (1200) to which the nail (1210) is coupled can be moved 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) can be longer than that of the nail assembly (1200).

[0087] The insertion groove (1110) may be formed to correspond to the nail assembly (1200). Accordingly, the inner surface of the insertion groove (1110) may include a pair of first inner wall surfaces (1110a) facing each other and a pair of second inner wall surfaces (1110b) facing each other to correspond to the nail assembly (1200). The second inner wall surface (1110b) may connect the pair of first inner wall surfaces (1110a) to each other, and in the present embodiment, the first inner wall surface (1110a) may be formed as a plane, and the second inner wall surface (1110b) may be formed to have a rounded, arc-shaped cross-section.

[0088] The bottom (1111) of the insertion groove (1110) located at the bottom of the insertion groove (1110) can be positioned at a certain distance upward from the bottom of the nail holder (1100), and a through hole (1120) can be formed at the bottom of the insertion groove (1110).

[0089] The through hole (1120) extends from the bottom (1111) of the insertion groove (1110) to the bottom of the nail holder (1100), and the bottom (1111) of the insertion groove (1110) is connected to the outside by this through hole (1120).

[0090] And, through this passage hole (1120), the nail (1210) can move downward from the nail holder (1100) and destroy the battery cell (100).

[0091] A pair of upper protrusions (1130) protruding upward may be formed on the upper portion of the nail holder (1100). The upper protrusions (1130) may extend upward from a pair of first inner wall surfaces (1110a) and be arranged on both sides of the nail assembly (1200), and may guide the insertion and up-and-down movement of the nail assembly (1200).

[0092] In addition, when mounting the thermal runaway test jig (1000) according to the present invention to the test box (10), the tester can easily insert it into the cell insertion port (251) of the test box (10) by holding the upper protrusion (1130).

[0093] Next, the process of mounting a thermal runaway test jig (1000) for a battery according to the present invention in a test box (10) and conducting a thermal runaway (TP) test will be described with reference to FIGS. 6 and 11.

[0094] As shown in Fig. 6, a thermal runaway test jig (1000) is mounted instead of a battery cell (100) in a cell insertion hole (251) in a thermal runaway test box (10), and the push bar (1300) is pressed downward while being coupled to a nail assembly (1200) through an insertion hole (211) formed in the upper plate (210) of the case (200) in the thermal runaway test box (10).

[0095] When the push bar (1300) is pressed 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 passage hole (1120). The nail assembly (1200) can move downward until it touches the bottom (1111) of the insertion groove (1110).

[0096] As shown in Fig. 11, in the case of the battery cell (100) positioned on the lower side, it is positioned opposite to the battery cell (100) positioned on the upper side, and the battery cell (100) positioned on the lower side can be positioned so that the upper cap (131) faces downward and the bottom part (121) of the battery case (120) faces upward.

[0097] Therefore, the bottom of the battery cell (100) may be destroyed by the nail (1210) moving downward.

[0098] Specifically, the nail (1210) can move downwards by penetrating the upper cell bottom frame (250), the middle 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 at the lower side and enter the interior of the battery cell (100).

[0099] As illustrated, in this embodiment, two nails (1210) positioned at the bottom of the nail assembly (1200) can penetrate the bottoms of two adjacent battery cells (100), respectively.

[0100] In this way, the thermal runaway test jig (1000) of the present invention is configured as described above, thereby improving the accuracy and safety of the thermal runaway test.

[0101] Specifically, in the present invention, precise alignment of the battery cell (100) to be destroyed and the nail (1210) is possible, and destruction can be performed at the precise location of the battery cell (100).

[0102] In addition, in the present invention, test failure due to bending of the nail (1210) does not occur, and thermal runaway (TP) testing is possible in multiple cells as well as in a single cell.

[0103] Although the present invention has been described with reference to preferred embodiments as described above, 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 invention pertains within a scope that does not depart from the spirit of the present invention.

[0104] The present invention can provide a thermal runaway test jig for a battery that can improve accuracy and safety in evaluating the stability of a battery module.

Claims

1. A nail assembly including a nail at the bottom; and A nail holder for accommodating the above nail assembly; Thermal runaway test jig for batteries including .

2. In paragraph 1, The above nail is a thermal runaway test jig for a battery that is detachably connected to the above nail assembly.

3. In paragraph 1, The above nail assembly is a thermal runaway test jig for a battery including a joining groove into which the nail is joined.

4. In paragraph 1, The above nail assembly is a thermal runaway test jig for a battery including a plurality of the above nails.

5. In paragraph 1, The above nail assembly is a thermal runaway test jig for a battery further including a push bar.

6. In paragraph 5, A thermal runaway test jig for a battery, wherein the nail assembly further includes an upper joining groove to which the push bar is joined.

7. In paragraph 1, The above nail holder is a thermal runaway test jig for a battery including an insertion groove into which the above nail assembly is inserted.

8. In paragraph 7, A thermal runaway test jig for a battery in which the above nail assembly is positioned so as to be movable up and down within the above insertion groove.

9. In paragraph 7, A thermal runaway test jig for a battery, wherein the bottom of the above insertion groove is positioned apart from the bottom of the above nail holder.

10. In paragraph 7, A thermal runaway test jig for a battery, wherein the nail holder further includes a passage hole through which the nail passes on the lower side of the insertion groove.

11. In paragraph 10, The above-mentioned through hole is a thermal runaway test jig for a battery that extends from the bottom of the above-mentioned insertion groove to the bottom of the above-mentioned nail holder.

12. In paragraph 10, A thermal runaway test jig for a battery, wherein a plurality of passage holes through which a plurality of nails pass are arranged at the lower part of the nail holder.

13. In paragraph 7, A thermal runaway test jig for a battery, wherein the nail holder further includes a pair of upper projections protruding upward at the top.

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