Venting pressure measuring apparatus and method
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- LG ENERGY SOLUTION LTD
- Filing Date
- 2026-01-21
- Publication Date
- 2026-07-30
Smart Images
Figure KR2026001290_30072026_PF_FP_ABST
Abstract
Description
Venting pressure measuring device and method
[0001] The present invention relates to a venting pressure measuring device and method. This application is a priority claim application based on Korean Patent Application No. 10-2025-0009739 filed on January 22, 2025. All contents disclosed in the specification and drawings of the said Korean application are incorporated by reference into this application.
[0002] As the demand for portable electronic products such as smartphones, tablet PCs, and smartwatches increases significantly and electric vehicles become increasingly widespread, research on batteries installed in them, particularly secondary batteries capable of repeated charging and discharging, is actively underway.
[0003] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to charge and discharge freely with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.
[0004] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and an outer casing, such as a battery case, that seals and houses the electrode assembly together with an electrolyte.
[0005] Generally, lithium secondary batteries can be classified according to the shape of the casing into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheet.
[0006] Recently, secondary batteries are widely used for driving or energy storage not only in small devices such as portable electronic devices, but also in medium and large devices such as electric vehicles and Energy Storage Systems (ESS).
[0007] In line with these changes in demand for secondary batteries, high-capacity secondary batteries are being developed, and along with this, interest in safety issues regarding secondary batteries is increasing.
[0008] The present invention aims to provide a venting pressure measuring device and method capable of measuring the pressure at which a venting cover breaks through actual testing, while reflecting the conditions under which thermal runaway occurs, thereby measuring a breaking pressure close to the breaking pressure in actual situations.
[0009] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description of the invention below.
[0010] A venting pressure measuring device according to one aspect of the present invention is a device for measuring the pressure at which a venting cover of a battery module is damaged, comprising: a pressure jig having a pressure space portion configured to apply pressure to the venting cover, on which the venting cover is placed and supported; and a top jig having a through hole formed at a position corresponding to the pressure space portion, which presses the venting cover toward the pressure jig, and wherein the gas flow when venting occurs in the battery module can be simulated by the shape of the pressure space portion and the through hole.
[0011] A venting pressure measuring device according to one embodiment of the present invention may further include a heating unit for heating the venting cover.
[0012] The heating unit may include a heating element embedded in the pressure jig.
[0013] The pressure applied to the venting cover is the pressure formed by the gas supplied to the pressure space, and the heating unit may be configured to heat the gas supplied to the pressure space.
[0014] The pressure space above can be formed in a shape corresponding to the shape of the through hole.
[0015] The pressure jig may be provided with a plurality of pressure spaces, and the top jig may be provided with a plurality of through holes at positions corresponding to the pressure spaces.
[0016] At least one of the plurality of through holes may be formed with at least one difference in size and shape from the other through holes.
[0017] It may further include a pressure generating unit configured to apply pressure to the plurality of pressure spaces, wherein at least two different pressures can be applied to each of the plurality of pressure spaces.
[0018] It may further include a control unit that measures the pressure at which the venting cover is damaged by the pressure applied by the pressure space above.
[0019] The above control unit has a pressure sensor that measures the pressure within the pressure space, and can determine the time of damage to the venting cover based on the pressure data measured by the pressure sensor.
[0020] The control unit measures the pressure when the venting cover is damaged twice, and the size of the through hole in the first measurement and the size of the through hole in the second measurement may be different from each other.
[0021] A method for measuring venting pressure according to another aspect of the present invention, for measuring the venting pressure of a venting cover used as a component of a battery module, may include: a placement step of placing the venting cover in a pressure jig having a pressure space; a fixing step of pressing the venting cover with a top jig having a through hole formed at a position corresponding to the pressure space to bring the venting cover into close contact with the pressure jig; and a pressure application step of applying pressure to the venting cover through the pressure space.
[0022] The above placement step, the above fixing step, and the above pressure application step are sequentially repeated twice, wherein the two fixing steps may be performed with top jigs in which at least one of the size and shape of the through hole is different.
[0023] Among the above second fixing steps, one fixing step may be performed with a top jig having a through hole larger than the pressure space, and the remaining fixing step may be performed with a top jig having a through hole of the same size as or smaller than the pressure space.
[0024] A separation line configured to facilitate breakage is formed on one side of the venting cover, and the one fixing step is performed with the side having the separation line formed facing the through hole, and the other fixing step can be performed with the side having the separation line formed facing the pressure space.
[0025] The battery module is provided with a venting hole for venting gas, and the through hole may be formed in a shape corresponding to the shape of the venting hole.
[0026] The pressure jig is provided with a plurality of pressure spaces, and the top jig is provided with a plurality of through holes at positions corresponding to the plurality of pressure spaces, and at least one of the plurality of through holes may be formed with at least one difference in size and shape from the other through holes.
[0027] The pressure applied to at least one of the plurality of pressure spaces can be controlled differently from the pressure applied to the remaining pressure spaces.
[0028] It may further include a heating step that is performed prior to or together with the pressure application step and heats the venting cover.
[0029] According to the present invention, the pressure at which the venting cover breaks, i.e., the venting pressure, can be accurately measured.
[0030] For example, by measuring the venting pressure while simulating the venting behavior of the gas occurring during thermal runaway, it is possible to measure the venting pressure under conditions similar to those in an actual battery module.
[0031] In addition, it is possible to measure both venting pressure in thermal runaway and thermal runaway diffusion situations, which enables the design of battery modules more stably.
[0032] According to one embodiment of the present invention, both the venting pressure in a thermal runaway situation and a thermal runaway diffusion situation can be measured in a single measurement process.
[0033] The following drawings attached to this specification illustrate embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.
[0034] FIG. 1 is a schematic exploded view to explain the configuration of a battery module.
[0035] FIG. 2 is an exploded view of a module case and a top cover having different structures.
[0036] FIG. 3 is a schematic diagram of a venting pressure measuring device according to one embodiment of the present invention.
[0037] FIG. 4 is an exploded perspective view of some components of a venting pressure measuring device according to one embodiment of the present invention.
[0038] FIG. 5 is a cross-sectional view of a venting pressure measuring device according to one embodiment of the present invention with a venting cover (BC) mounted thereon.
[0039] FIG. 6 is a schematic cross-sectional view of a pressure jig according to another embodiment of the present invention.
[0040] Figure 7 is a top-down view (Z-axis direction) of the pressure jig shown in Figure 6.
[0041] FIG. 8 is a cross-sectional view showing a part of the battery module to explain the thermal runaway situation within the battery module.
[0042] FIG. 9 is a schematic perspective view of a pressure jig and a top jig according to another embodiment of the present invention.
[0043] FIG. 10 is a cross-sectional view schematically illustrating two situations in which the venting cover of a battery module is damaged.
[0044] FIG. 11 is a block diagram showing a hardware configuration for implementing a control unit (160) included in a venting pressure measuring device (100) according to one embodiment of the present invention.
[0045] FIG. 12 is a schematic flowchart of a venting pressure measurement method according to one embodiment of the present invention.
[0046] FIG. 13 is a schematic flowchart of a venting pressure measurement method according to another embodiment of the present invention.
[0047] In parts of the attached drawings, corresponding components are given the same reference numerals. Those skilled in the art understand that the drawings are intended to illustrate elements simply and clearly and are not necessarily drawn to scale. For example, to aid in understanding various embodiments, the dimensions of some elements depicted in the drawings may be exaggerated compared to others. Additionally, elements of known technology that are useful or essential in commercially viable embodiments may often be omitted so as not to hinder the spirit of the various embodiments of the present invention.
[0048] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.
[0049] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application.
[0050] In this specification, terms indicating directions such as up, down, left, right, front, and back may be used; however, these terms are used merely for convenience of explanation, and it is obvious to those skilled in the art that they may vary depending on the location of the object or the position of the observer.
[0051] In this specification, terms indicating direction, such as internal or external, may be used; unless otherwise specifically stated, internal means the direction toward the central part of the battery module, and external means the opposite direction.
[0052] This specification includes various embodiments. Detailed descriptions of identical or similar parts of other embodiments are omitted, and the description focuses on the differences between each embodiment.
[0053] Multiple secondary batteries can be electrically connected and housed together inside a module case to form a single battery module. In this case, each secondary battery included in the battery module can be referred to as a battery cell. Furthermore, multiple such battery modules can be connected to form a single battery pack.
[0054] A battery module may be configured to include a case, a plurality of battery cells housed inside the case, and a busbar assembly for electrically connecting the plurality of battery cells. In the event that an event such as thermal runaway occurs in a battery module configured in this manner, it is very important to prevent the thermal runaway from propagating to adjacent battery cells or modules.
[0055] To this end, a venting cover is provided on one side of the case, configured to effectively discharge high-temperature, high-pressure gases generated during thermal runaway of the battery cells. For example, the venting cover has a separation line formed therein that allows it to be damaged more easily than other parts during thermal runaway, and the high-temperature, high-pressure gases are discharged to the outside by breaking through the part where this separation line is formed.
[0056] Meanwhile, in order to design a battery module or battery pack reliably, it is necessary to accurately determine the pressure at which the venting cover breaks. Conventionally, the pressure at which the venting cover breaks was predicted using data on the venting cover's specifications, such as material properties (strength, tensile strength, elongation, heat resistance, etc.) and thickness, and this result was reflected in the battery module design. Alternatively, it was merely a matter of using measured data without sufficiently reflecting the geometric structure of the actual battery module (or battery pack) or the various conditions that occur during thermal runaway.
[0057] As such, conventional methods have limitations in accurately measuring the pressure at which the venting cover actually breaks. Taking these points into consideration, the present invention provides an apparatus and method capable of accurately measuring the pressure at which the venting cover breaks.
[0058] A venting pressure measuring device according to one embodiment of the present invention may be a device for measuring the pressure at which a venting cover provided in a battery module is damaged. First, the battery module and the venting cover will be described. FIG. 1 is a schematic exploded perspective view for explaining the configuration of a battery module. FIG. 2 is an exploded perspective view of a module case and a top cover having different structures.
[0059] Referring to FIG. 1, a battery module (1000) according to one embodiment of the present invention may include a plurality of battery cells (1100), a busbar assembly (1200) electrically connecting the plurality of battery cells (1100), a module case (1300), and a venting cover (BC).
[0060] Among the above configurations, the module case (1300) may be configured to accommodate a plurality of battery cells (1100) and a busbar assembly (1200) by forming an empty space inside. For example, the module case (1300) may have a main body frame (1310) and an end frame (1320) that covers the open ends of the main body frame (1310). The main body frame (1310) may have an upper plate (1311), a lower plate (1312), and a side plate (1313). Additionally, a plurality of venting holes (BH) may be formed in the upper plate (1311).
[0061] A venting cover (BC) can be positioned between a plurality of battery cells (1100) and the upper plate (1311) of the main body frame (1310). For example, the venting cover (BC) can be attached to the lower surface of the upper plate (1311) of the main body frame (1310). The venting cover (BC) can be made of a flame-resistant material. For example, it can be made of mica or fiber reinforced board (FRB). A separation line (BL) can be formed on the venting cover (BC). The separation line (BL) can be formed on the upper surface of the venting cover (BC), for example, on the surface facing the upper plate (1311).
[0062] The term "separation line" (BL) may be used as a general term including perforated lines, notching lines, cutting lines, shredding lines, or tear lines. According to one embodiment, multiple separation lines (BL) may be formed at positions corresponding to the venting holes (BH). The separation lines (BL) may be configured to be separated by pressure applied to the venting cover (BC), for example, by high-pressure gas generated during thermal runaway. For example, the separation lines (BL) may be formed by forming notching lines or cut lines on the venting cover (BC).
[0063] When the battery module (1000) is in a normal state, the venting cover (BC) blocks the venting hole (BH), thereby preventing external foreign substances, such as moisture or dust, from entering the interior of the battery module (1000). In the event of thermal runaway of the battery module (1000), the venting hole (BH) may be opened as the separation line (BL) of the venting cover (BC) is damaged. The pressure at the time the venting cover (BC) is damaged can be called the venting pressure. When the separation line (BL) of the venting cover (BC) is damaged, flames and gases can be rapidly discharged through the venting hole (BH) of the main body frame (1310), thereby preventing or suppressing the spread of thermal runaway to adjacent battery modules (1000).
[0064] Meanwhile, the venting cover (BC) and venting hole (BH) may be implemented in other forms. For example, as shown in FIG. 2, a separation line (BL) may be formed on the upper plate (1311) of the main body frame (1310A). Then, a top cover (1330) may be attached to this upper plate (1311). At this time, a plurality of venting holes (BH) may be formed in the top cover (1330). In this structure, the top cover (1330) may be configured to function as a venting cover.
[0065] A venting cover may be a term encompassing configurations that can be rapidly damaged during thermal runaway to discharge gas and flames inside the battery module (1000) to the outside.
[0066] The venting pressure measuring device may be for measuring the pressure when the above-mentioned venting cover (BC) is damaged. Hereinafter, a venting pressure measuring device (100) according to an embodiment of the present invention will be described with reference to FIGS. 3 to 5. In describing the venting pressure measuring device (100), it will be explained together how each component of the venting pressure measuring device (100) can be matched with a certain component or phenomenon in the battery module (1000).
[0067] FIG. 3 is a schematic diagram of a venting pressure measuring device according to one embodiment of the present invention, and FIG. 4 is an exploded perspective view of some components of a venting pressure measuring device according to one embodiment of the present invention. FIG. 5 is a cross-sectional view of a venting pressure measuring device according to one embodiment of the present invention with a venting cover (BC) mounted thereon.
[0068] Referring to FIGS. 3 to 5, the venting pressure measuring device (100) according to the present embodiment may include a pressure jig (110) and a top jig (120). A pressure space (S1) may be formed in the pressure jig (110), and a through hole (S2) may be formed in the top jig (120). According to one embodiment, the pressure space (S1) and the through hole (S2) may be configured to simulate gas flow when venting occurs in the battery module (1000).
[0069] The pressure jig (110) can support the venting cover (BC). For example, the pressure jig (110) may be formed in a flat plate shape, and the venting cover (BC) may be placed and supported on the upper surface (the surface in the Z-axis direction) of the pressure jig (110). At this time, the upper surface of the pressure jig (110) may be formed to correspond to the venting cover (BC). For example, if the venting cover (BC) is rectangular, the upper surface of the pressure jig (110) may also be formed in a rectangular shape. Accordingly, the venting cover (BC) can be stably supported on the pressure jig (110).
[0070] Additionally, a pressure space (S1) configured to apply pressure to a venting cover (BC) may be formed in the pressure jig (110). For example, the pressure space (S1) may be formed on the upper surface of the pressure jig (110). At this time, the pressure space (S1) may be formed concavely downward from the upper surface. According to one embodiment, as shown in FIG. 4, the pressure space (S1) may be formed penetrating the upper and lower surfaces of the pressure jig (110). As shown in FIG. 3, the pressure space (S1) may be connected to a pressure generator (130). Here, the pressure generator (130) may be for forming pressure in a certain space or area. When the pressure generator (130) is operated, pressure may be formed in the pressure space (S1). Then, the pressure formed in the pressure space (S1) may be applied to the venting cover (BC).
[0071] For example, a venting cover (BC) may be placed on the upper surface of the pressure jig (110) to block the pressure space (S1). At this time, as described above, a separation line (BL) may be formed on the venting cover (BC), and the area where the separation line (BL) is formed may be placed over the pressure space (S1). Then, the pressure formed in the pressure space (S1) may be applied to the venting cover (BC). Additionally, pressure may be applied from the venting cover (BC) to the area where the separation line (BL) is formed.
[0072] The pressure space (S1) can be matched to a space where a battery cell (1100) is placed in a battery module (1000), for example, a space inside a module case (1300). The two spaces can be matched to each other in that they are spaces where pressure is formed that damages the venting cover (BC).
[0073] The top jig (120) may be configured to bring the venting cover (BC) into close contact with the pressure jig (110). According to one embodiment, the top jig (120) may be positioned above the pressure jig (110), and the venting cover (BC) may be positioned between the top jig (120) and the pressure jig (110). The top jig (120) presses the venting cover (BC) downward, thereby bringing the venting cover (BC) into close contact with the pressure jig (110). Additionally, a through hole (S2) may be provided in the top jig (120). At this time, the through hole (S2) of the top jig (120) may be formed at a position corresponding to the pressure space (S1) of the pressure jig (110). For example, the through hole (S2) may be positioned above the pressure space (S1) so as to face each other with the pressure space (S1).
[0074] The top jig (120) can be matched to the top plate (1311) in FIG. 1 or the top cover (1330) in FIG. 2. The two configurations can be matched to each other in that when high pressure is applied to the venting cover (BC), the venting cover (BC) is pressed so that it is fixed without being pushed out by the high pressure. At this time, the through hole (S2) of the top jig (120) can be matched to the venting hole (BH) of the battery module (1000).
[0075] In the venting pressure measuring device (100) configured in this manner, the venting cover (BC) can be placed on the upper surface of the pressure jig (110), and then the venting cover (BC) can be fixed in close contact with the pressure jig (110) using the top jig (120). In this state, if the pressure in the pressure space (S1) is increased, this pressure can be applied to the venting cover (BC). As the pressure applied to the venting cover (BC) increases, if it exceeds a certain size, the venting cover (BC) may be damaged. The pressure at this time can be called the 'venting pressure,' for example, the pressure at which venting occurs in the battery module (1000).
[0076] According to the above embodiment, the venting pressure measuring device (100) can measure the pressure at which the venting cover (BC) breaks, for example, the venting pressure, by actually applying pressure to the venting cover (BC). Therefore, the venting pressure can be measured more accurately and quickly. In the conventional case, the venting pressure was calculated simply based on the specifications of the venting cover (BC) itself without considering the conditions at which the venting cover (BC) breaks, for example, the structure in which the venting cover (BC) is combined within the battery module (1000), and accordingly, the accuracy was limited.
[0077] In this embodiment, the structure in which the venting cover (BC) is combined with the battery module (1000) is matched and reflected in the configuration of the venting pressure measuring device (100), for example, the pressure space (S1) of the pressure jig (110) and the through hole (S2) of the top jig (120), thereby simulating the flow of venting gas (hereinafter referred to as "venting gas behavior") in the actual battery module (1000). Accordingly, the venting pressure of the venting cover in the battery module (1000) can be accurately measured. The embodiments simulating the venting gas behavior will be further explained below.
[0078] A venting pressure measuring device (100) according to one embodiment of the present invention may further include a heating unit (140). The heating unit (140) can heat a venting cover (BC). For example, the heating unit (140) may be installed around the venting cover (BC) to heat the venting cover (BC) placed on the pressure jig (110).
[0079] In the event of a thermal runaway phenomenon in the battery module (1000), the venting cover (BC) may be heated to a high temperature. The heating unit (140) is for measuring the venting pressure of the venting cover (BC) during a thermal runaway phenomenon, and more accurate measurement results can be obtained when testing under conditions identical or similar to the environment during a thermal runaway.
[0080] According to the above embodiment, by applying pressure after heating (or while heating) the venting cover (BC) with the heating unit (140), the venting pressure of the venting cover (BC) heated to a high temperature, i.e., under conditions similar to a thermal runaway phenomenon, can be measured. Therefore, the venting pressure can be measured more accurately.
[0081] The heating unit (140) may be configured to heat the gas supplied to the pressure space (S1) of the pressure jig (110). For example, gas, such as air, is supplied from the pressure generating unit (130) to the pressure space (S1) of the pressure jig (110), and pressure may be formed as this air is compressed within the pressure space (S1). Then, the pressure thus formed may be applied to the venting cover (BC).
[0082] At this time, the heating unit (140) can heat the air supplied to the pressure space (S1). For example, as shown in FIG. 3, the heating unit (140) can be installed in a connecting pipe (131) through which air flows from the pressure generating part (130) to the pressure space (S1). The heating unit (140) can heat the air flowing through this connecting pipe (131).
[0083] According to the above embodiment, pressure can be applied to the venting cover (BC) with air heated to a high temperature, which may be the same as the situation in which the venting cover (BC) in the battery module (1000) is damaged by high temperature and high pressure gas, for example, the situation in which venting occurs. Therefore, the venting pressure can be measured more accurately.
[0084] The heating unit (140) may include a heating element (141). The heating element (141) may have a structure embedded in the pressure jig (110). This will be explained with reference to FIGS. 6 and 7. FIG. 6 is a schematic cross-sectional view of a pressure jig (110A) according to another embodiment of the present invention. FIG. 7 is a plan view of the pressure jig (110) shown in FIG. 5, viewed from above (Z-axis direction).
[0085] Referring to FIG. 6, a heating element (141) may be embedded in a pressure jig (110A). The pressure jig (110A) may be formed in a flat plate shape and may have a pressure space (S1) provided therein. Additionally, a heating element (141) may be embedded in the upper part of the pressure jig (110A). The heating element (141) generates heat when power is applied and may be implemented in the form of, for example, a nichrome wire. The nichrome wire can heat the venting cover (BC) to a high temperature. Furthermore, the nichrome wire has a fast response speed, for example, can quickly raise or lower the temperature, thereby allowing the temperature of the venting cover to be controlled quickly.
[0086] According to one embodiment, the pressure jig (110A) may be formed with a triple structure. For example, the pressure jig (110A) may include a support plate (111A), a heating plate (112A), and an insulating plate (113A). The support plate (111A) may be formed in a plate shape and may be composed of a material with high rigidity, such as metal. The heating plate (112A) may be formed in a shape corresponding to the support plate (111A). The heating plate (112A) may be coupled to the upper side of the support plate (111A). A heating element (141) may be embedded in the heating plate (112A). The heating plate (112A) may be made of a material with excellent thermal conductivity, such as aluminum. The insulating plate (113A) may be placed between the support plate (111A) and the heating plate (112A). The insulation plate (113A) may be made of a material with excellent thermal insulation properties, such as ceramic. Additionally, the pressure space (S1) described above may be formed by penetrating the support plate (111A), the insulation plate (113A), and the heating plate (112A).
[0087] According to one embodiment, the support plate (111A), the insulation plate (113A), and the heating plate (112A) may be detachably coupled to each other. In this case, there is an advantage that only the part can be replaced if any one of the plates is damaged. However, this is not limited thereto, and the support plate, the insulation plate, and the heating plate may be modularized and formed as a single unit.
[0088] According to the above embodiment, the venting cover (BC) can be heated quickly. In addition, the heating temperature of the venting cover (BC) can be controlled accurately and easily.
[0089] Meanwhile, the temperature of the heating element (141) can be controlled independently for each region. For example, as shown in FIG. 7, the heating element (141) can be divided into multiple regions depending on the buried area. For example, in FIG. 7, the heating elements (141) arranged on the same line along the Y-axis direction can be grouped into the same group, thereby dividing them into four groups. Furthermore, the temperature of the heating element (141) can be controlled independently for each group, which can be achieved by controlling the current supplied to each group.
[0090] According to the above embodiment, various parts of the venting cover (BC) can be heated to different temperatures. Therefore, the venting pressure can be measured by changing the heating conditions of the venting cover (BC) according to various conditions (conditions in terms of temperature) that may occur during a thermal runaway phenomenon, and thus the venting pressure can be measured more accurately.
[0091] In the venting pressure measuring device (100), the through hole (S2) of the top jig (120) can be formed in a shape corresponding to the shape of the venting hole (BH) of the battery module (1000). As previously discussed, the top jig (120) is matched to the upper plate of the module case (1300), and the through hole (S2) can be matched to the venting hole (BH) of the battery module (1000). Accordingly, by configuring the shape of the through hole (S2) to correspond to the shape of the venting hole (BH), the venting gas behavior in the battery module (1000) can be simulated more accurately. For example, the through hole (S2) can be formed in a shape that extends long in one direction. Additionally, the through hole (S2) can be configured so that a part thereof has a curved shape, for example, an arc. In addition, as described below, when a plurality of through holes (S2) are formed, the plurality of through holes (S2) may be arranged in rows and columns. Furthermore, the formation of through holes (S2) in this manner may be due to the fact that the venting holes (BH) in the actual battery module (1000) are formed with the shape and arrangement described above.
[0092] Referring again to FIG. 4, the top jig (120) of the venting pressure measuring device (100) may include a fixed plate (121) and a pressure frame (122). The fixed plate (121) is formed in a flat plate shape and may be placed on the upper side of the venting cover (BC). A through hole (S2) may be formed in the fixed plate (121). As can be seen by comparing FIG. 1 and FIG. 4, the through hole (S2) of the venting pressure measuring device (100) may be formed to correspond to the shape of the venting hole (BH) of the battery module (1000). Here, the corresponding shape may mean that the shape is identical or similar, and there may be a difference in size. The fixed plate (121) of the venting pressure measuring device (100) can be matched to the upper plate of the module case (1300) of the battery module (1000), and the through hole (S2) can be matched to the venting hole (BH).
[0093] The pressure frame (122) of the venting pressure measuring device (100) may be positioned on the upper side of the fixed plate (121). For example, the pressure frame (122) may be coupled to the upper surface of the fixed plate (121), and according to one embodiment, may be coupled so as to be detachable. The pressure frame (122) may press the fixed plate (121) downward (e.g., in the -Z-axis direction), for example, toward the pressure jig (110). For example, a structure in which the pressure frame (122) presses the fixed plate (121) can be implemented through a configuration such as fastening a fixed clamp between the pressure frame (122) and the pressure jig (110). The pressure frame (122) may press the fixed plate (121), and accordingly, the fixed plate (121) may be tightly fixed toward the pressure jig (110).
[0094] As illustrated in FIG. 4, the pressure frame (122) may be configured to press only the two edges of the fixed plate (121). In this regard, as illustrated in FIG. 1, the upper plate (configured to match the fixed plate) (1311) in the battery module (1000) may have a structure in which only two sides are joined and fixed to the side plate (1313). And, to mimic this structure, the pressure frame (122) may be configured to press only the two edge portions of the fixed plate (121).
[0095] According to the embodiment of the above configuration, the structure at the point where venting occurs in the actual battery module (1000), for example, the shape of the venting hole (BH) and the structure in which the upper plate (1311) and the side plate (1313) are combined can be reflected, and thus the venting gas behavior can be simulated more accurately.
[0096] As described above, the pressure space (S1) of the venting pressure measuring device (100) can be matched to the internal space of the module case (1300). Therefore, if the pressure space (S1) is configured to be similar to the internal structure of the module case (1300), more precisely the structure of the space to which pressure is applied to the venting cover (BC), the behavior of the venting gas can be accurately simulated. However, since various components including a plurality of battery cells (1100) are arranged inside the module case (1300), it may be practically difficult to simulate the pressure space (S1) exactly as the internal structure of the module case (1300).
[0097] In this embodiment, the venting pressure measuring device (100) can be configured such that the shape of the pressure space (S1) corresponds to the shape of the through hole (S2), thereby simulating the behavior of the venting gas. For example, the pressure space (S1) of the venting pressure measuring device (100) can be formed with a shape corresponding to the through hole (S2). At this time, the shape of the pressure space (S1) may refer to a cross-sectional shape on a plane (XY plane) where the pressure space (S1) and the through hole (S2) face each other. The shape of the through hole (S2) may also refer to a cross-sectional shape in the XY plane direction.
[0098] With reference to FIG. 8, the reason for simulating the structure of the battery module (1000) as described above, for example, the reason and effect of forming the shape of the pressure space (S1) of the venting pressure measuring device (100) to correspond to the shape of the through hole (S2) will be explained. FIG. 8 is a cross-sectional view showing a part of the battery module (1000) to explain the thermal runaway situation within the battery module (1000).
[0099] Referring to FIG. 8, a venting hole (BH) is formed in the upper plate (1311) of the module case, and a venting cover (BC) can be attached to this upper plate (1311). And, a plurality of battery cells (1100) can be arranged on the lower side of the venting cover (BC). A thermal runaway phenomenon may first occur in some of the battery cells (1110) within the battery module (1000), and gas (and flame) may begin to be emitted from these battery cells (1100).
[0100] At this time, the battery cells (1100) are stacked with a narrow gap between them, so gas can flow through the gaps between the battery cells (1100), for example, in a vertical direction (e.g., Z-axis direction). Therefore, pressure may be concentrated in a part of the venting cover (BC), for example, in the area marked BZ in FIG. 8. To elaborate, the pressure inside the module case (1300) may rise uniformly throughout, but the inside of the module case (1300) is filled with various components including the battery cells (1100), and due to these components, the pressure in some parts of the battery module (1000), for example, in the area marked BZ, may be locally higher than at other points. And, since the pressure in the BZ area may rise first, venting may occur first in this part.
[0101] In summary, when pressure is applied to the venting cover (BC) due to the occurrence of thermal runaway, the pressure may be concentrated locally in a narrow area, and venting may occur for the first time in this area. Accordingly, in this embodiment, the space where pressure is applied to the venting cover (BC), for example, the pressure space (S1) of the venting pressure measuring device (100), can be simulated as a narrow space.
[0102] Furthermore, the venting cover (BC) of the battery module (1000) can be divided into a part supported by the upper plate (1311) and a part not supported. The part not supported refers to the area corresponding to the venting hole (BH), and the part supported refers to the remaining area. Also, the part supported by the upper plate (1311) may have greater strength against pressure in the Z-axis direction than the part not supported. Therefore, when pressure is applied to the venting cover (BC), the area corresponding to (facing) the venting hole (BH) may be the most vulnerable to pressure. Meanwhile, since a separation line (BL) is formed in that part, it may be even more vulnerable to pressure. And, from another perspective, this can be interpreted as pressure being concentrated in this part, that is, the area corresponding to the venting hole (BH).
[0103] As described above, the pressure applied to the venting cover (BC) during thermal runaway of the battery module (1000) can be interpreted as being concentrated in a narrow area, for example, in an area facing the venting hole (BH). Therefore, if the pressure space (S1) of the venting pressure measuring device (100) is formed in a shape corresponding to the through hole (S2) (e.g., a configuration matching the venting hole (BH)), the gas venting behavior can be simulated more accurately.
[0104] FIG. 9 is a schematic perspective view of a part of the configuration of a venting pressure measuring device (100) according to another embodiment of the present invention.
[0105] Referring to FIG. 9, a plurality of pressure spaces (S1) and through holes (S2) may be provided. A plurality of through holes (S2) may be formed at positions corresponding to the pressure spaces (S1). For example, a pressure jig (110) may have a plurality of pressure spaces (S1). For example, as shown in FIG. 9, 12 pressure spaces (S1) may be provided on the upper surface of the pressure jig (110). A plurality of through holes (S2a, S2b) may be provided in the top jig (120A). For example, the fixing plate (121A) of the top jig (120A) may have the same number of through holes (S2a, S2b) as the pressure spaces (S1). At this time, the through holes (S2a, S2b) may be arranged so as to correspond to the pressure space (S1), for example, so that the through holes (S2a, S2b) and the pressure space (S1) face each other.
[0106] Meanwhile, at least one of the plurality of through holes (S2a, S2b) may be formed with at least one difference in size and shape from the other through hole (S2a). For example, as shown in FIG. 9, five through holes (S2b) may be formed with the same shape and size as each other, and the remaining through hole (S2a) may be formed with the same shape as the five through holes (S2b) but with a smaller size.
[0107] The above-mentioned through holes (S2a, S2b) are configured to match the venting hole (BH) in the battery module (1000) and may be one of the important factors in simulating venting gas behavior. For example, by changing the relative sizes of the through holes (S2a, S2b), various types of venting gas behavior can be simulated. Therefore, according to the above-mentioned embodiment, venting pressure under various conditions can be accurately measured.
[0108] With regard to the size of the through hole (S2), the venting gas behavior is further explained with reference to FIG. 10. FIG. 10 is a cross-sectional view schematically showing two situations in which the venting cover (BC) of the battery module (1000) is damaged.
[0109] Referring to FIG. 10, venting in a battery module (1000) can be classified into two forms. First, it may be a form in which thermal runaway occurs inside the battery module (1000) and gas is ejected from inside the battery module (1000) to the outside. For example, this may be the direction of gas behavior that can occur in a typical thermal runaway situation, and this is represented as a positive pressure direction in FIG. 10. Second, it may be a form in which the venting cover (BC) is damaged from the outside to the inside of the battery module (1000) by high-pressure gas generated by the thermal runaway phenomenon of an adjacent battery module (1000). This may be the direction of gas behavior that can occur in a situation where thermal runaway propagates between battery modules (1000), and this is represented as a negative pressure direction in FIG. 10.
[0110] In the above positive pressure direction, gas can flow from the narrow and complex space of the battery module (1000) to the open space outside. Accordingly, as shown in FIG. 10, the through hole (S2) through which pressure is discharged can be simulated to be larger than the pressure space (S1) where pressure is applied. At this time, the venting cover (BC) can be positioned so that the separation line (BL) faces the through hole (S2). This may be because when the venting cover (BC) is coupled to the battery module (1000), the separation line (BL) of the venting cover (BC) is positioned to face the upward direction, that is, the upper plate (1311) (see FIG. 1).
[0111] In the reverse pressure direction, gas can flow from a wide space outside the module case (1300) into a narrow space, for example, inside the battery module (1000). In the reverse pressure direction, the pressure space (S1) to which pressure is applied can be matched to the external space of the module case (1300), and the through hole (S2) can be matched to the narrow space inside the battery module (1000). Accordingly, as shown in FIG. 10, the through hole (S2) can be modeled to be smaller (or similar) in size than the pressure space (S1). At this time, the venting cover (BC) can be positioned so that the separation line (BL) faces the pressure space (S1) side. This is because, during thermal runaway propagation in the actual battery module (1000), pressure can be applied to the upper surface of the venting cover (BC) (e.g., the surface where the separation line (BL) is formed).
[0112] As described above, the venting gas behavior may differ in the positive pressure direction and the negative pressure direction, and this can be simulated by changing the relative size of the through hole (S2) and the pressure space (S1). At this time, the reason for changing the size of the through hole (S2) may be that it may be easier to change the size of the through hole (S2) formed in the top jig (120) due to the structure of the venting pressure measuring device (100).
[0113] According to the embodiment of the above configuration, the venting pressure can be measured while simulating different venting gas behaviors, for example, behaviors in the positive pressure direction and the negative pressure direction. At this time, since through holes (S2) of different sizes are formed in the top jig (120), the venting pressure during the two behaviors can be accurately measured in a single measurement experiment.
[0114] However, to measure the venting pressure in the positive pressure direction and the reverse pressure direction in a single measurement experiment, forming the position of the separation line (BL) formed on the venting cover (BC) differently in each part may help to measure the venting pressure more accurately. For example, as shown in FIG. 10, the separation line (BL) may be formed on the upper surface of the venting cover (BC) in the part placed in the relatively large through hole (S2), and the separation line (BL) may be formed on the lower surface of the venting cover (BC) in the part placed in the relatively small through hole (S2).
[0115] Meanwhile, the venting pressure measuring device (100) may further include the aforementioned pressure generator (130). Here, the pressure generator (130) may be intended to form pressure in a certain space or area. For example, the pressure generator (130) may operate by increasing pressure by compressing a gas or liquid or injecting it into a sealed space. As an example, the pressure generator (130) may be implemented in the form of a compressor.
[0116] The pressure generator (130) can apply pressure to a plurality of pressure spaces (S1) of the venting pressure measuring device (100). For example, the pressure generator (130) can apply different pressures to at least two different parts of the plurality of pressure spaces (S1). This will be explained again below with reference to FIG. 3.
[0117] The pressure generator (130) can be connected to a plurality of pressure spaces (S1) through a connecting pipe (131). A valve (132) can be installed in each connecting pipe (131). At this time, the connecting pipes (131) connected to the plurality of pressure spaces (S1) can be connected in groups or individually, or the valves (132) can be installed in groups or individually. In this way, the pressure applied to the pressure spaces (S1) can be controlled individually or in groups. For example, if the connecting pipe (131) and the valve (132) are installed individually in each pressure space (S1), pressure can be applied individually to each pressure space (S1) through the control of the valve (132).
[0118] According to the embodiment of the above configuration, by changing the form (magnitude and rate of increase) of the pressure applied to various points of the venting cover (BC) in consideration of the thermal runaway situation of the battery module (1000), the venting gas behavior can be simulated more accurately.
[0119] Referring again to FIGS. 4 and 5, the venting pressure measuring device (100) may further include a gasket (150). The gasket (150) may be for sealing between the pressure jig (110) and the venting cover (BC). For example, as shown in FIG. 4, the gasket (150) may be formed in a plate shape. According to one embodiment, an opening (S3) may be formed in the gasket (150) at a position corresponding to the pressure space (S1). The gasket (150) may be placed between the upper surface of the pressure jig (110) and the venting cover (BC). The gasket (150) may seal between the pressure jig (110) and the venting cover (BC), for example, to prevent pressure formed in the pressure space (S1) from leaking between the upper surface of the pressure jig (110) and the venting cover (BC). The gasket (150) can be composed of various materials such as non-metallic materials, semi-metallic materials, metallic materials, and graphite. For example, considering the characteristics of the venting pressure measurement process, the gasket (150) can be made of a material that can maintain sealing properties and durability even under high temperature and high pressure conditions, such as metal and graphite.
[0120] According to the above-described embodiment, pressure can be efficiently applied to the venting cover (BC). In addition, since there is no pressure leakage, the pressure at which the venting cover (BC) breaks, i.e., the venting pressure, can be accurately measured.
[0121] Meanwhile, as illustrated in FIG. 3, the venting pressure measuring device (100) may further include a control unit (160). The control unit (160) can measure the pressure when the venting cover (BC) is damaged. For example, the control unit (160) can specify the time when the venting cover (BC) is damaged. Then, the control unit (160) can check the pressure applied to the pressure space (S1) at the specified time and determine this as the venting pressure.
[0122] According to the embodiment of the above configuration, the pressure at which the venting cover (BC) is damaged can be automatically measured. Therefore, the user does not need to directly check the time at which the venting cover (BC) is damaged and the pressure at that time, and thus the pressure measurement process can be made easier and more accurate.
[0123] The control unit (160) can determine the time of failure of the venting cover (BC) based on pressure data within the pressure space (S1) of the venting pressure measuring device (100). For example, the control unit (160) may include a pressure sensor. The pressure sensor may be installed in the pressure space (S1) or in a space connected to the pressure space (S1), for example, a connecting pipe (131). The pressure sensor can measure the pressure within the pressure space. The control unit (160) is electrically connected to the pressure sensor and can receive pressure data measured by the pressure sensor in real time.
[0124] When pressure is applied to the pressure space (S1), the pressure in the pressure space (S1) can continuously increase. Then, at the point where venting occurs, the compressed air inside the pressure space (S1) is discharged to the outside, and accordingly, the pressure inside the pressure space (S1) can drop instantaneously. The control unit (160) can identify the moment when the pressure drops in the received data as the venting point. And, the pressure at the venting point (pressure in the pressure data) can be set as the venting pressure.
[0125] According to the above embodiment, the venting time can be accurately detected by utilizing the real-time pressure change of the pressure space (S1), and the pressure at this time can be set as the venting pressure. Therefore, the venting pressure can be accurately measured.
[0126] Meanwhile, the control unit (160) can measure the venting pressure of the venting cover (BC) twice. In addition, the size of the through hole (S2) of the top jig (120) may differ in the two measurements. For example, as previously mentioned, the venting pressure of the venting cover (BC) in the positive pressure direction and the venting pressure in the reverse pressure direction may differ. For example, the control unit (160) may measure the venting pressure in the positive pressure direction first and the venting pressure in the reverse pressure direction second. In addition, the size of the through hole (S2) of the top jig (120) used in the first measurement of the venting pressure in the positive pressure direction and the second measurement of the venting pressure in the reverse direction may differ. For example, in the measurement of the venting pressure in the positive pressure direction, the through hole (S2) may have a larger size than the pressure space (S1). Also, in the measurement of the venting pressure in the reverse pressure direction, the through hole (S2) may have a smaller size than the pressure space (S1).
[0127] Furthermore, in the above first and second venting pressure measurement processes, the direction of the surface on which the separation line (BL) is formed in the venting cover (BC) may change. In the first measurement, the surface on which the separation line (BL) is formed may be positioned to face the through hole (S2). And, in the second measurement, the surface on which the separation line (BL) is formed may be positioned to face the pressure space (S1). As the reason for such positioning has been explained in FIG. 10 above, further explanation is omitted.
[0128] Meanwhile, the control unit (160) may further include a temperature sensor capable of measuring the temperature of the venting cover (BC). For example, the temperature sensor may be installed on the surface of a top jig or a pressure jig and may measure the temperature of the venting cover (BC) at that point. The control unit (160) is electrically connected to and can control the pressure generator (130), valve (132), pressure sensor, temperature sensor, and heating unit (140). The control unit (160) can control the pressure (size and rate of increase) applied to the venting cover (BC) and the temperature of the venting cover (BC) through the control of the pressure generator (130), valve (132), and heating unit (140). The control unit (160) can receive data measured by the pressure sensor and temperature sensor in real time, and through this, can determine and store the overall situation when the venting cover (BC) is damaged. Here, the overall situation may refer to the pressure and temperature when the venting cover (BC) is damaged (pressure and temperature data may be available for each pressure space).
[0129] FIG. 11 is a block diagram showing a hardware configuration for implementing a control unit (160) included in a venting pressure measuring device (100) according to one embodiment of the present invention.
[0130] A control unit (160) according to one embodiment of the present invention may include an MCU (162), a memory (164), a communication I / F (166), and an input / output I / F (168). The MCU (162) is a Micro Controller Unit and is a processor that executes various programs stored in the memory (164), processes various data used in these programs, and performs the functions of the control unit (160).
[0131] The memory (164) can store operation data of various programs regarding the operation of a lithium secondary battery system for the operation of the control unit (160). Multiple such memories (164) may be provided as needed. The memory (164) may be a volatile memory or a non-volatile memory. As a volatile memory, RAM, DRAM, SRAM, etc. may be used for the memory (164). As a non-volatile memory, ROM, PROM, EAROM, EPROM, EEPROM, flash memory, etc. may be used for the memory (164). The examples of the memories (164) listed above are merely examples and are not limited to these.
[0132] The communication I / F (166) is configured to transmit and receive various data with a server and may be various devices capable of supporting wired or wireless communication. For example, through the communication I / F (166), programs for the operation of the control unit (160) or various data may be transmitted or received via wired or wireless from an external server provided separately. The input / output I / F (168) may provide an interface that enables data transmission and reception by connecting an input device (not shown), such as a keyboard, mouse, or touch panel, and an output device (not shown), such as a display, to the MCU (162).
[0133] Hereinafter, a method for measuring venting pressure according to an embodiment of the present invention will be described. In this case, the description will be made by utilizing the configuration of the aforementioned venting pressure measuring device (100). Furthermore, the parts described in the above-described venting pressure measuring device (100) will be omitted or mentioned briefly.
[0134] FIG. 12 is a schematic flowchart of a venting pressure measurement method according to one embodiment of the present invention. The venting pressure measurement method (M100) according to this embodiment may be a method for measuring the venting pressure of a venting cover (BC) provided in a battery module (1000). Referring to FIG. 12 and FIG. 4, the venting pressure measurement method (M100) according to this embodiment may include a placement step (M110), a fixing step (M120), and a pressure application step (M130).
[0135] In the placement step (M100), a venting cover (BC) can be placed on the pressure jig (110) of the venting pressure measuring device (100). At this time, a pressure space (S1) may be provided in the pressure jig (110). For example, the pressure space (S1) may be provided on the upper surface of the pressure jig (110). The pressure space (S1) may be connected to a pressure generator (130). The venting cover (BC) may be placed on and supported on the upper surface of the pressure jig (110).
[0136] In the fixing step (M120), the venting cover (BC) of the venting pressure measuring device (100) can be pressed against the pressure jig (110). For example, a top jig (120) can be positioned on the upper side of the venting cover (BC). The top jig (120) can press the venting cover (BC) downward (Z-axis direction), and accordingly, the venting cover (BC) can be pressed against and fixed to the upper surface of the pressure jig (110). A through hole (S2) can be formed in the top jig (120).
[0137] In the pressure application step (M130), pressure can be applied to the venting cover (BC) through the pressure space (S1) of the pressure jig (110). For example, if pressure is generated in the pressure space (S1) by a pressure generator (130), this pressure can be applied to the venting cover (BC). If the applied pressure becomes greater than a specific pressure, for example, the venting pressure, the venting cover (BC) may be damaged. At this time, the venting pressure can be determined by measuring the pressure at which the venting cover (BC) is damaged.
[0138] According to the above embodiment, the venting pressure, which is the pressure at which the venting cover (BC) breaks, can be measured while actually applying pressure to the venting cover (BC). Therefore, the venting pressure can be measured more accurately and quickly. In this embodiment, by reflecting the structure in which the venting cover (BC) is combined in the battery module (1000), the behavior of the venting gas in the actual battery module (1000) can be simulated, and thus the venting pressure can be measured accurately.
[0139] The above placement step (M110), fixing step (M120), and pressure application step (M130) may be repeated sequentially twice. Additionally, the two fixing steps (M110) may be performed with top jigs (120) in which at least one of the size and shape of the through hole (S2) is different.
[0140] For example, as mentioned earlier, the venting pressure at which the venting cover (BC) breaks may differ in the positive pressure direction and the reverse pressure direction. Accordingly, in order to measure the venting pressure in both the positive pressure direction and the reverse pressure direction, the placement step (M110), the fixing step (M120), and the pressure application step (M130) may be repeated twice.
[0141] For example, when first measuring the venting pressure in the positive pressure direction, the venting cover (BC) can be placed on the pressure jig (110) (M110). Then, the venting cover (BC) can be tightly fixed to the pressure jig (110) using the top jig (120) (M120). Afterwards, by applying pressure to the pressure space (S1) and measuring the pressure at which the venting cover (BC) breaks, the venting pressure in the positive pressure direction can be measured (M130).
[0142] Then, the above process can be repeated. For example, a new venting cover (BC) can be placed on the pressure jig (110) (M110). Then, the venting cover (BC) can be fixed tightly to the pressure jig (110) using the top jig (120) (M120). At this time, the venting cover (BC) can be fixed using the top jig (120) with a different size of through hole (S2). Afterwards, the venting pressure in the reverse pressure direction can be measured by applying pressure to the pressure space (S1) (M130).
[0143] According to the above embodiment, the venting pressure of the venting cover (BC) can be measured in both the positive pressure direction and the reverse pressure direction. In this case, considering that the venting gas behavior is different in the positive pressure direction and the reverse pressure direction, the venting pressure can be measured more accurately by making the size of the through hole (S2) different.
[0144] Among the above second fixing step (M120), one fixing step (M120) may be performed with a top jig (120) having a through hole (S2) larger than the pressure space (S1), and the remaining fixing step (M120) may be performed with a top jig (120) having a through hole (S2) smaller than or equal in size to the pressure space (S1).
[0145] For example, as examined in FIG. 10 above, the size of the through hole (S2) in the positive pressure direction and the reverse pressure direction may be different, which may be more suitable for venting gas flow. Accordingly, in one fixing step, for example, in the process of measuring the venting pressure in the positive pressure direction, the venting cover (BC) can be fixed in close contact with the pressure jig (110) using a top jig (120) in which the size of the through hole (S2) is larger than the size of the pressure space (S1). Then, in the other fixing step, for example, in the process of measuring the venting pressure in the reverse pressure direction, the venting cover (BC) can be fixed in close contact with the pressure jig (110) using a top jig (120) in which the size of the through hole (S2) is smaller than (or equal to) the size of the pressure space (S1).
[0146] According to the configuration of the above-described embodiment, the venting gas behavior in the positive pressure direction and the back pressure direction can be simulated more accurately. Accordingly, the venting pressure in the positive pressure direction and the back pressure direction can be measured more accurately.
[0147] Meanwhile, a separation line (BL) may be provided on one side of the venting cover (BC). For example, a separation line (BL) may be provided on the upper surface of the venting cover (BC), as has been explained.
[0148] Additionally, one of the two fixing steps (M120) can be performed with the side of the venting cover (BC) having the separation line (BL) formed facing the through hole (S2). The remaining fixing step (M120) can be performed with the side of the venting cover (BC) having the separation line (BL) formed facing the pressure space (S1).
[0149] For example, the above-mentioned single fixing step may be a process of measuring the venting pressure in the positive pressure direction. In this process, the surface on which the separation line (BL) is formed may be positioned so as to face upward, for example, the through hole (S2). This has been explained previously in FIG. 10.
[0150] And, the remaining fixing step (M120) may be a process of measuring the venting pressure in the reverse pressure direction. And, in this process, the surface on which the separation line (BL) is formed may be positioned so as to face downward, that is, toward the pressure space (S1).
[0151] According to the configuration of the above-described embodiment, not only the venting gas behavior in the positive pressure direction and the reverse pressure direction, but also the direction of the separation line (BL) of the venting cover (BC) at that time can be simulated more accurately. Therefore, the venting pressure in the positive pressure direction and the reverse pressure direction can be measured more accurately.
[0152] The through hole (S2) may be formed to correspond to the shape of the venting hole (BH). For example, a venting hole (BH) may be provided in the battery module (1000). The venting hole (BH) is intended to discharge gas and flames to the outside in the event of thermal runaway and may be formed in the upper plate of the module case (1300). The through hole (S2) may be formed in a shape corresponding to the shape of the venting hole (BH). In simulating the venting gas behavior, the through hole (S2) is configured to match the venting hole (BH), as previously explained.
[0153] According to the configuration of the above-described embodiment, the venting gas behavior can be simulated more accurately. Accordingly, the venting pressure can be measured more accurately.
[0154] The pressure space (S1) of the pressure jig (110) and the through holes (S2) of the top jig (120) may be provided in multiple numbers. The multiple through holes (S2) may be formed at positions corresponding to the pressure space (S1). For example, the pressure jig (110) may have multiple pressure space (S1). For example, as shown in FIG. 8, 12 pressure space (S1) may be provided on the upper surface of the top jig (120). The top jig (120) may have multiple through holes (S2). For example, the fixing plate of the top jig (120) may have the same number of through holes (S2a, S2b) as the pressure space (S1). At this time, the through holes (S2a, S2b) can be arranged to correspond to the pressure space (S1), for example, the through holes (S2a, S2b) and the pressure space (S1) can be arranged to face each other.
[0155] Meanwhile, at least one of the plurality of through holes (S2a, S2b) may be formed with at least one difference in size and shape from the other through holes (S2). For example, as shown in FIG. 9, five through holes (S2b) may be formed larger than the remaining through holes (S2a).
[0156] The above-mentioned through holes (S2a, S2b) are configured to match the venting hole (BH) in the battery module (1000) and may be one of the important determining factors in simulating venting gas behavior. For example, by changing the size of the through holes (S2a, S2b), different types of gas venting behavior can be simulated. Therefore, venting pressure under a wider variety of conditions can be accurately measured.
[0157] By configuring the invention in this manner, the venting pressure in the positive pressure direction and the reverse pressure direction can be measured simultaneously. For example, at a location where the size of the through hole (S2b) is larger than the pressure space (S1), the venting gas behavior in the positive pressure direction can be simulated. And at a location where the size of the through hole (S2a) is smaller than the pressure space (S1), the venting gas behavior in the reverse pressure direction can be simulated. Accordingly, by forming a separation line (BL) on the upper surface of the venting cover (BC) in the portion positioned below the large through hole (S2b) and forming a separation line (BL) on the lower surface of the portion positioned below the small through hole (S2a), and then performing the venting pressure measurement method using this venting cover (BC), the venting pressure in the positive pressure direction and the reverse pressure direction can be accurately measured simultaneously.
[0158] The pressure applied to at least one of the plurality of pressure spaces (S1) can be controlled differently from the pressure applied to the remaining pressure spaces (S1). Specifically, the pressure spaces (S1) are connected to a pressure generator (130), and the connecting pipes (131) connected to the plurality of pressure spaces (S1) can be connected in groups or individually. In this way, the pressure applied to the pressure spaces (S1) can be controlled individually or in groups.
[0159] According to the embodiment of the above configuration, by changing the form (magnitude and rate of increase) of the pressure applied to various points of the venting cover (BC) in consideration of the thermal runaway situation of the battery module (1000), the venting gas behavior can be simulated more accurately.
[0160] FIG. 13 is a schematic flowchart of a venting pressure measurement method according to another embodiment of the present invention. Referring to FIG. 13, the venting pressure measurement method (M200) according to the present embodiment may include a placement step (M210), a fixing step (M220), a pressure application step (M230), and a heating step (M240). Among these, the placement step (M210), the fixing step (M220), and the pressure application step (M230) are substantially the same or similar as those described above, so a description thereof may be omitted.
[0161] The heating step (M240) is a step of heating the venting cover (BC), and this step can be performed with the heating unit described above. The heating step (M240) can be performed before the pressure application step (M230). For example, after the venting cover (BC) is fixed to the pressure jig (110), the venting cover (BC) can be heated to a temperature similar to the temperature in a thermal runaway situation. Then, pressure can be applied to the venting cover (BC) to measure the venting pressure.
[0162] In contrast, the venting cover (BC) can be heated by starting to heat the venting cover (BC) after it is fixed to the pressure jig (110), and the venting cover (BC) can be heated continuously even while pressure is applied to the venting cover (BC). In fact, considering that the venting cover (BC) is continuously heated in a thermal runaway situation, this case may be more similar to an actual thermal runaway situation.
[0163] According to the above embodiment, the venting pressure can be measured when the venting cover (BC) is heated to a high temperature, similar to an actual thermal runaway state.
[0164] Although embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above. Various modifications are possible by those skilled in the art without departing from the essence of the invention as claimed in the claims, and such modifications should not be understood individually from the technical spirit or perspective of the present invention.
Claims
1. As a device for measuring venting pressure, A pressure jig having a pressure space configured to apply pressure to the venting cover of a battery module, on which the venting cover of the battery module is placed and supported; and A top jig having a venting cover that is pressed against the pressure jig and a through hole formed at a position corresponding to the pressure space; A venting pressure measuring device configured such that when venting occurs in the battery module, the gas flow is simulated by the shape of the pressure space and the through hole, and the pressure at which the venting cover is damaged is measured.
2. In Paragraph 1, A venting pressure measuring device further comprising a heating unit for heating the venting cover.
3. In Paragraph 2, The above heating unit is a venting pressure measuring device comprising a heating element embedded in the pressure jig.
4. In Paragraph 2, The pressure applied to the venting cover is the pressure formed by the gas supplied to the pressure space, and The above heating unit is a venting pressure measuring device configured to heat the gas supplied to the pressure space.
5. In Paragraph 1, The above pressure space is a venting pressure measuring device formed with a shape corresponding to the shape of the through hole.
6. In Paragraph 1, The pressure jig is provided with a plurality of pressure spaces, and A venting pressure measuring device in which a plurality of through holes are provided in the top jig at positions corresponding to the pressure space.
7. In Paragraph 6, A venting pressure measuring device in which at least one of the plurality of through holes is formed differently from other through holes in at least one of its size and shape.
8. In Paragraph 6, A venting pressure measuring device further comprising: a pressure generating unit configured to apply pressure to the plurality of pressure spaces, wherein different pressures can be applied to at least two or more parts of the plurality of pressure spaces.
9. In Paragraph 1, A venting pressure measuring device further comprising: a control unit for measuring the pressure at which the venting cover is damaged by the pressure applied by the pressure space above.
10. In Paragraph 9, The above control unit includes a pressure sensor that measures the pressure within the pressure space, and a venting pressure measuring device that determines the point of damage to the venting cover based on pressure data measured by the pressure sensor.
11. In Paragraph 9, A venting pressure measuring device characterized in that the control unit measures the pressure when the venting cover is damaged twice, wherein the size of the through hole in the first measurement and the size of the through hole in the second measurement are different.
12. A method for measuring the venting pressure of a venting cover used as a component of a battery module, wherein A placement step of placing the venting cover on a pressure jig having a pressure space; A fixing step of pressing the venting cover with a top jig having a through hole formed at a position corresponding to the pressure space, thereby pressing the venting cover against the pressure jig; A method for measuring venting pressure comprising: a pressure application step of applying pressure to the venting cover through the pressure space.
13. In Paragraph 12, The above placement step, the above fixing step, and the above pressure application step are performed sequentially twice, wherein A venting pressure measuring method in which the above two fixing steps are performed with top jigs in which at least one of the size and shape of the through hole is different.
14. In Paragraph 13, A method for measuring venting pressure, wherein, among the above-mentioned second fixing steps, one fixing step is performed with a top jig having a through hole larger than the pressure space, and the remaining fixing step is performed with a top jig having a through hole of the same size as or smaller than the pressure space.
15. In Paragraph 14, A separation line configured to facilitate damage is formed on one side of the above-mentioned venting cover, and The above single fixing step is performed with the surface on which the separation line is formed positioned to face the through hole, and The above remaining fixing step is a venting pressure measuring method in which the surface on which the separation line is formed is positioned to face the pressure space.
16. In Paragraph 12, The above pressure jig is provided with a plurality of pressure spaces, and A method for measuring venting pressure, wherein the above-described top jig is provided with a plurality of through holes at positions corresponding to the plurality of pressure spaces, and at least one of the plurality of through holes is formed differently in size and shape from at least one of the other through holes.
17. In Paragraph 16, A venting pressure measurement method in which the pressure applied to at least one of the plurality of pressure spaces is controllable differently from the pressure applied to the remaining pressure spaces.
18. In Paragraph 12, A method for measuring venting pressure further comprising a heating step for heating the venting cover, which is performed prior to or together with the pressure application step.