cell

Abstract

The application provides an electric core and relates to the technical field of batteries. The electric core comprises a shell and two explosion-proof valves. The shell comprises a surrounding part and a bottom plate connected with each other. The bottom plate comprises a mounting body and two bosses. The mounting body comprises an abutting plane and a reference plane. The bosses protrude from the reference plane, so that the position corresponding to the bosses of the bottom plate is provided with an exhaust groove which is open to the side where the abutting plane is located. The explosion-proof valves are arranged in the mounting ports of the bosses. The groove wall of the exhaust groove intersects with the abutting plane to form a first closed curve. The area of the region in the outer contour of the first projection pattern formed by the projection of the bottom plate on a projection plane is S1. The area of the region in the outer contour of the second projection pattern formed by the projection of the first closed curve on the projection plane is S2. And S1 and S2 satisfy the following formula: S1 / S2>1. In this way, the pole group does not shield the explosion-proof valve, the exhaust effect of the explosion-proof valve is ensured, and the safety performance of the electric core is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell. Background Technology

[0002] Lithium-ion batteries are widely used in various fields such as transportation power supply, power storage, new energy storage power supply, aerospace and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention capability, and long cycle life. A typical energy storage cell includes a cover plate, casing, bare cell, insulating film, side plates, electrode assembly, and electrolyte.

[0003] Energy storage cells generally have a large capacity and higher safety requirements. Their positive and negative terminals can be set on the same cover plate, and the explosion-proof valve is set on the opposite cover plate to achieve thermal and electrical separation and improve the safety performance of the cell.

[0004] However, when thermal runaway occurs in the battery cell, the explosion-proof valve opens to release pressure and exhaust gas. As the pressure decreases, the electrode assembly will move towards the explosion-proof valve under the impact of the high-temperature and high-pressure airflow inside the battery cell. This causes the front end of the electrode assembly to block the explosion-proof valve, which will significantly reduce the exhaust effect of the explosion-proof valve and thus weaken the safety performance of the battery cell. Summary of the Invention

[0005] In view of this, this application provides a battery cell that can, to some extent, solve the problem that electrode movement during thermal runaway of the battery cell can block the explosion-proof valve.

[0006] One aspect of this application provides a battery cell, the battery cell including a housing and two explosion-proof valves, the housing including an enclosure and a base plate, the base plate being connected to one end of the enclosure in a first direction, the base plate and the enclosure enclosing an accommodating space, the base plate including a mounting body and two bosses, the mounting body including an abutment plane and a reference plane opposite to each other in the first direction, the bosses protruding from the reference plane toward a side away from the abutment plane, so that the base plate has an exhaust groove opening toward the side where the abutment plane is located corresponding to the position of the bosses, the two bosses being spaced apart along a second direction, the second direction being perpendicular to the first direction; The boss has an installation port that extends through the boss in the first direction. The installation port is connected to the exhaust groove. The two explosion-proof valves are respectively installed in the two installation ports opened on the two bosses. The wall of the exhaust groove intersects the abutting plane at a first closed curve. A plane perpendicular to the first direction is defined as the projection plane. The base plate is projected onto the projection plane along the first direction to form a first projected shape. The first closed curve is projected onto the projection plane along the first direction to form a second projected shape. The area of ​​the region within the outer contour of the first projected shape is... The area of ​​the region located within the outer contour of the second projected graphic is , and satisfy: .

[0007] Preferably, the boss includes a mounting surface and a connecting surface. The connecting surface includes a first connecting end and a second connecting end that are opposite to each other in the first direction. The first connecting end is connected to the mounting surface, and the second connecting end is connected to the reference plane. The mounting surface is projected onto the projection plane along the first direction to form a third projection pattern. The area of ​​the region located within the outer contour of the third projection pattern is [area missing]. ; The mounting surface intersects the inner wall of the mounting opening at a second closed curve. The second closed curve is projected onto the projection plane along the first direction to form a fourth projection pattern. The area of ​​the region located within the outer contour of the fourth projection pattern is... ; and satisfy: .

[0008] Preferably, the dimension of the base plate in the third direction is: The third direction is perpendicular to the first direction and the second direction, respectively, and the dimension of the boss in the third direction is [missing information]. , and satisfy: .

[0009] Preferably, the wall thickness of the mounting body is The wall thickness of the boss is , and satisfy: .

[0010] Preferably, the dimension of the boss in the first direction is: , and satisfy: .

[0011] Preferably, the angle at which the first connecting end is inclined relative to the second connecting end toward the interior of the exhaust groove is . , satisfy: .

[0012] Preferably, the distance between the end faces of the boss and the housing in the second direction is... , satisfy: .

[0013] Preferably, the battery cell further includes an electrode assembly disposed within the receiving space. The electrode assembly includes an electrode group and an insulating film. The electrode group forms two recesses. The recesses are recessed from the end face of the electrode group facing the base plate in the first direction toward the interior of the electrode group. The two recesses are spaced apart along the second direction. The insulating film includes a covered body and an extension connected to each other. The covered body covers the side of the electrode assembly around the perimeter. The extension is respectively attached to the end face of the electrode assembly facing the base plate in the first direction and the inner wall of the two recesses, so that the extension forms two grooves, and the two grooves are respectively connected to the two exhaust grooves.

[0014] Preferably, the area of ​​the electrode assembly projected onto the projection plane is... The dimension of the exhaust groove in the first direction is The dimension of the groove in the first direction is The dimension of the battery cell in the first direction is , , , , and satisfy: .

[0015] Preferably, the mounting opening is divided into a first mounting cavity and a second mounting cavity by a partition surface. The two ends of the second mounting cavity in the second direction are respectively connected to the first mounting cavity and the vent groove. The explosion-proof valve is located within the first mounting cavity and abuts against the partition surface. The width of the partition surface is... , satisfy: .

[0016] The battery cell of this application includes a housing and two explosion-proof valves. The housing includes an enclosure and a base plate. The base plate is connected to one end of the enclosure in a first direction. The base plate and the enclosure enclose a receiving space. The base plate includes a mounting body and two bosses. The mounting body includes an abutment plane and a reference plane that are opposite to each other in the first direction. The bosses protrude from the reference plane to the side away from the abutment plane, so that the base plate forms an exhaust groove facing the side where the abutment plane is located at the position of the boss. The two bosses are spaced apart along a second direction. The bosses have mounting openings that penetrate the bosses along the first direction and communicate with the exhaust grooves. The two explosion-proof valves are respectively disposed in the two mounting openings of the two bosses. The groove wall of the exhaust groove intersects the abutment plane at a first closed curve. The plane perpendicular to the first direction is defined as the projection plane. The base plate is projected onto the projection plane along the first direction to form a first projection pattern. The first closed curve is projected onto the projection plane along the first direction to form a second projection pattern. The area of ​​the region located within the outer contour of the first projection pattern is... The area of ​​the region located within the outer contour of the second projected graphic is , and satisfy: This design ensures that the volume of the venting channel is sufficient to meet the venting requirements in the event of thermal runaway. When thermal runaway occurs in the battery cell, the explosion-proof valve opens. Even if there is intermittent movement of the electrode assembly, high-temperature gas can still flow through the venting channel to the explosion-proof valve and then be discharged through it. In this way, the electrode assembly will not obstruct the explosion-proof valve, ensuring its venting effect and improving the safety performance of the battery cell. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A three-dimensional structural diagram of the battery cell is shown from one perspective; Figure 2 A three-dimensional structural diagram of the battery cell is shown from another perspective; Figure 3 A diagram showing the relative positions of the housing and the explosion-proof valve from one perspective; Figure 4 This diagram shows the relative positions of the housing and the explosion-proof valve from another perspective. Figure 5 A schematic diagram of the three-dimensional structure of the insulating film is shown; Figure 6 An exploded view of the battery cell is shown; Figure 7A schematic diagram of the shell's planar structure is shown; Figure 8 Show Figure 7 A cross-sectional view of the shell along N-N'. Figure 9 Show Figure 8 Enlarged view of section M; Figure 10 A three-dimensional structural diagram of the shell is shown from one perspective; Figure 11 Show Figure 10 Enlarged view of the Q section; Figure 12 A three-dimensional structural diagram showing another perspective of the shell; Figure 13 Show Figure 12 Enlarged view of section P in the middle.

[0019] Reference numerals: 1-Shell; 11-Base plate; 111-Mounting body; 1111-Reference plane; 1112-Abutting plane; 112-Boss; 1121-First connecting end; 1122-Second connecting end; 1123-Mounting surface; 1124-Connecting surface; 113-Mounting port; 1131-First mounting cavity; 1132-Second mounting cavity; 1133-Separating surface; 114-Chamfered portion; 12-Enclosing component; 121-First plate; 122-Second plate; 13-Exhaust groove; 14-Accommodation space; 15-First closed curve; 16-Second closed curve; 2-Explosion-proof valve; 3-Insulating film; 31-Covering body; 32-Extension; 33-Groove; 4-Cover plate; F1-First direction; F2-Second direction; F3-Third direction. Detailed Implementation

[0020] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0021] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0022] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0023] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0024] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0025] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.

[0026] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0027] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0028] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0029] The following will combine Figures 1 to 13 Describe the battery cell, in Figures 1 to 13 In this configuration, the first direction F1, the second direction F2, and the third direction F3 are perpendicular to each other. Preferably, the first direction F1 is parallel to the height direction of the battery cell, the second direction F2 is parallel to the length direction of the battery cell, and the third direction F3 is parallel to the thickness direction of the battery cell.

[0030] One aspect of this application provides a battery cell, which includes a housing 1 and two explosion-proof valves 2. The housing 1 includes a surrounding member 12 and a base plate 11. The base plate 11 is connected to one end of the surrounding member 12 in a first direction F1. The base plate 11 and the surrounding member 12 enclose a receiving space 14. The base plate 11 includes a mounting body 111 and two bosses 112. The mounting body 111 includes an abutment plane 1112 and a reference plane 1111 that are opposite to each other in the first direction F1. The bosses 112 protrude from the reference plane 1111 to the side away from the abutment plane 1112, so that the base plate 11 has an exhaust groove 13 that opens toward the side where the abutment plane 1112 is located at the position corresponding to the bosses 112. Two bosses 112 are spaced apart along the second direction F2; each boss 112 has a mounting port 113 extending through it along the first direction F1, which communicates with the exhaust channel 13. Two explosion-proof valves 2 are respectively installed in the two mounting ports 113 on the two bosses 112; the wall of the exhaust channel 13 intersects the abutment plane 1112 at a first closed curve 15. The plane perpendicular to the first direction F1 is defined as the projection plane. The base plate 11 is projected onto the projection plane along the first direction F1 to form a first projection pattern, and the first closed curve 15 is projected onto the projection plane along the first direction F1 to form a second projection pattern. The area of ​​the region located within the outer contour of the first projection pattern is... The area of ​​the region located within the outer contour of the second projected graphic is , and satisfy: This ensures that the volume of the exhaust channel 13 is sufficient to meet the venting requirements in the event of thermal runaway. When thermal runaway occurs in the battery cell, the explosion-proof valve 2 opens. Even if the electrode assembly experiences axial movement, high-temperature gas can still flow through the exhaust channel 13 to the explosion-proof valve 2 and then be discharged through it. In this way, the electrode assembly will not obstruct the explosion-proof valve 2, ensuring its venting effect and improving the safety performance of the battery cell.

[0031] In addition, At that time, the volume of the exhaust groove 13 was small, affecting the exhaust effect. There was a risk that the explosion-proof valve 2 would fail to open and the housing 1 would rupture in the event of thermal runaway of the blade battery cell. At that time, the volume of the exhaust groove 13 is relatively large, which will affect the structural strength of the cover plate 4 itself; At the same time, it can ensure the strength of the shell 1 and the exhaust effect in case of thermal runaway.

[0032] Optionally, the dimensions of the cell in the first square are: The dimension of housing 1 in the second direction F2 is The dimensions of housing 1 on the third direction F3 are: , , , and satisfy: , , .

[0033] Preferably, the boss 112 can be formed by stamping, and the distance between the two opposite end faces of the boss 112 and the mounting body 111 in the third direction F3 is equal.

[0034] Optionally, such as Figure 11 As shown, the wall of the exhaust groove 13 includes a chamfered portion 114, which is connected to the abutment plane 1112. The chamfered portion 114 and the abutment plane 1112 intersect at a first closed curve 15. The width of the chamfered portion 114 is... , satisfy: This increases the volume of the exhaust channel 13, thereby improving exhaust efficiency during thermal runaway.

[0035] In the embodiments of this application, such as Figure 9 As shown, the wall thickness of the mounting body 111 is The wall thickness of boss 112 is , and satisfy: This is to ensure the yield rate of the stamping of the protrusions and the structural strength of the shell 1.

[0036] Preferably, satisfy: .

[0037] Furthermore, the dimension of the boss 112 in the first direction F1 is... , and satisfy: This is to ensure the yield rate of stamping the boss 112 and the structural strength of the shell 1.

[0038] like Figure 4 As shown, the dimension of boss 112 in the third direction F3 is , and satisfy: .exist At that time, the dimensions of boss 112 on the third direction F3 The size is relatively large, which will affect the structural strength of shell 1; in At that time, the dimensions of boss 112 on the third direction F3 The small size of the exhaust vent 13 affects the exhaust effect, and there is a risk that the explosion-proof valve 2 may fail to open and the casing 1 may rupture in the event of thermal runaway. At the same time, it can ensure the strength of the shell 1 and the exhaust effect in case of thermal runaway.

[0039] like Figure 4 As shown, the distance between the boss 112 and the end face of the housing 1 in the second direction F2 is , satisfy: This is to ensure the yield rate of the 112 stamping boss.

[0040] like Figure 10 , Figure 11 , Figure 12 and Figure 13 As shown, the boss 112 includes a mounting surface 1123 and a connecting surface 1124. The connecting surface 1124 includes a first connecting end 1121 and a second connecting end 1122 that are opposite to each other in the first direction F1. The first connecting end 1121 is connected to the mounting surface 1123, and the second connecting end 1122 is connected to the reference plane 1111. The angle at which the first connecting end 1121 is inclined relative to the second connecting end 1122 toward the interior of the exhaust groove 13 is [value missing]. , satisfy: This is to ensure the yield rate of stamping the boss 112 and the structural strength of the shell 1.

[0041] Optionally, the mounting opening 113 is divided into a first mounting cavity 1131 and a second mounting cavity 1132 by a partition surface 1133, wherein the cross-sectional area of ​​the first mounting cavity 1131 is larger than the cross-sectional area of ​​the second mounting cavity 1132. The two ends of the second mounting cavity 1132 in the second direction F2 are respectively connected to the first mounting cavity 1131 and the vent groove 13. The explosion-proof valve 2 is located inside the first mounting cavity 1131 and abuts against the partition surface 1133. The explosion-proof valve 2 is welded to the boss 112. The width of the partition surface 1133 is... , satisfy: This is to meet the requirements for weld width and depth of explosion-proof valve 2, and to ensure the welding strength of explosion-proof valve 2.

[0042] Furthermore, the mounting surface 1123 is projected onto the projection plane along the first direction F1 to form a third projection pattern, and the area of ​​the region located within the outer contour of the third projection pattern is... The mounting surface 1123 intersects the inner wall of the mounting opening 113 at the second closed curve 16. The second closed curve 16 is projected onto the projection plane along the first direction F1 to form a fourth projected shape. The area of ​​the region located within the outer contour of the fourth projected shape is... ; and satisfy: ,exist At that time, the mounting opening 113 was too large, which would affect the structural strength of the boss 112; At that time, the installation port 113 was too small, and the explosion-proof valve 2 was also too small, which would affect the exhaust efficiency during thermal runaway. At the same time, it can ensure the structural strength of the boss 112, and at the same time ensure the exhaust efficiency during thermal runaway.

[0043] In the embodiments of this application, such as Figure 5 and Figure 6 As shown, the battery cell also includes an electrode assembly, which includes an electrode group and an insulating film 3. Both the electrode group and the insulating film 3 are disposed within the receiving space 14. The electrode group forms two recesses, which are recessed from the end face of the electrode group facing the base plate 11 in the first direction F1 toward the interior of the electrode group. The two recesses are arranged at intervals along the second direction F2. The insulating film 3 includes a covered body 31 and an extension 32 connected to each other. The covered body 31 covers the side of the electrode group around its perimeter. The extension 32 is respectively attached to the end face of the electrode group facing the base plate 11 in the first direction F1 and the inner wall of the two recesses, so that the extension 32 forms two grooves 33. The two grooves 33 are respectively connected to two venting grooves 13. Thus, the grooves 33 and the venting grooves 13 connected to the grooves 33 form a venting channel. When the battery cell experiences thermal runaway, high-temperature gas can flow through the venting channel to the explosion-proof valve 2 and then be discharged through the explosion-proof valve 2, thereby improving the venting efficiency of thermal runaway.

[0044] Furthermore, the area of ​​the electrode assembly projected onto the projection plane is... The dimensions of the exhaust vent 13 in the first direction F1 are: The dimension of groove 33 in the first direction F1 is The dimensions of the battery cell in the first direction F1 are , , , , and satisfy: .exist At that time, the exhaust channel was small in size, resulting in poor exhaust performance of the battery cell. This led to problems such as the explosion-proof valve 2 failing to open and the casing 1 tearing during thermal runaway. At that time, the volume of the exhaust groove 13 is relatively large, which will affect the structural strength of the shell 1 itself. At the same time, it can ensure the strength of the shell 1 and the exhaust effect in case of thermal runaway.

[0045] Preferably, and satisfy: , .

[0046] like Figure 6 As shown, the enclosure 12 includes two first plates 121 and two second plates 122. The two first plates 121 are spaced apart along the second direction F2, and the two second plates 122 are spaced apart along the third direction F3. The two ends of the first plates 121 on the third direction F3 are respectively connected to the two second plates 122, so that the enclosure 12 is formed into a hollow cuboid structure.

[0047] Preferably, the surround 12 and the base plate 11 can be integrally formed.

[0048] In addition, the battery cell also includes a cover plate 4, which is welded to the side of the surround 12 opposite to the base plate 11 in the first direction F1.

[0049] Select rated discharge energy for Rated charging power for Rated voltage for Ten groups of battery cells were subjected to thermal runaway performance tests. The parameters of the ten cells in each group were identical, while the parameters of the cells in different groups were different. , , , , , , , , and The values ​​are shown in the table below.

[0050] Test environment: The battery cell under test is placed in the thermal runaway test apparatus. A sheet-like heating element is arranged on the largest surface area of ​​the battery cell. The size of the sheet-like heating element is no larger than the area of ​​the largest surface area of ​​the battery cell, and the power of the heating element needs to be greater than [missing information]. (For example, the power of the heating element can be) ); Test equipment: A temperature sensor with a diameter of less than 1 mm is placed at the center of the other surface with the largest area in the battery cell. The temperature sampling period is set to 1 second, and the test is set to continuously detect three temperature rise rate values ​​that are greater than or equal to... Alternatively, fire or explosion can be used as the criteria for determining thermal runaway. The test cell is then connected to the charging and discharging device and its voltage data sampling line. Experimental method: Perform constant current charging, start heating, and record time, voltage, current, temperature, and rate of temperature rise. Record experimental phenomena, including expansion, leakage, smoke, fire, explosion, shell rupture, and rupture location; trigger the judgment condition for thermal runaway or when the temperature reaches... Or the test time reaches When the time is up, stop the power supply and heating, observe for 1 hour, and record the time, voltage, current, temperature, temperature rise rate, and test phenomena, including expansion, leakage, smoke, fire, explosion, shell cracking, crack location, electrode group movement, electrode damage, and tray detachment.

[0051] The test results of 10 groups of battery cells are as follows:

[0052] Based on the table above, it can be seen that... At that time, the venting effect of the blade battery cell was poor, and the blade battery cell had problems such as the explosion-proof valve 2 failing to open in the event of thermal runaway and the casing 1 tearing. At that time, the venting effect of the blade battery cell was poor, and the blade battery cell had problems such as the explosion-proof valve 2 failing to open and the casing 1 tearing during thermal runaway. , At that time, the production of cover plate 4 was normal. When thermal runaway occurred in the blade cell, the explosion-proof valve 2 could be opened normally. The electrode group would not block the explosion-proof valve 2, and the high-temperature gas could be discharged through the explosion-proof valve 2, thus improving the safety performance of the blade cell.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell, characterized in that, The battery cell includes a housing and two explosion-proof valves. The housing includes an enclosure and a base plate. The base plate is connected to one end of the enclosure in a first direction. The base plate and the enclosure enclose an accommodating space. The base plate includes a mounting body and two bosses. The mounting body includes an abutment plane and a reference plane that are opposite to each other in the first direction. The bosses protrude from the reference plane to a side away from the abutment plane, so that the base plate has an exhaust groove that opens toward the side where the abutment plane is located at the position of the boss. The two bosses are spaced apart along a second direction, which is perpendicular to the first direction. The boss has an installation port that extends through the boss in the first direction. The installation port is connected to the exhaust groove. The two explosion-proof valves are respectively installed in the two installation ports opened on the two bosses. The wall of the exhaust groove intersects the abutting plane at a first closed curve. A plane perpendicular to the first direction is defined as the projection plane. The base plate is projected onto the projection plane along the first direction to form a first projected shape. The first closed curve is projected onto the projection plane along the first direction to form a second projected shape. The area of ​​the region located within the outer contour of the first projected shape is... The area of ​​the region located within the outer contour of the second projected graphic is , and satisfy: .

2. The battery cell according to claim 1, characterized in that, The boss includes a mounting surface and a connecting surface. The connecting surface includes a first connecting end and a second connecting end that are opposite to each other in the first direction. The first connecting end is connected to the mounting surface, and the second connecting end is connected to the reference plane. The mounting surface is projected onto the projection plane along the first direction to form a third projection pattern. The area of ​​the region located within the outer contour of the third projection pattern is [area missing]. ; The mounting surface intersects the inner wall of the mounting opening at a second closed curve. The second closed curve is projected onto the projection plane along the first direction to form a fourth projection pattern. The area of ​​the region located within the outer contour of the fourth projection pattern is... ; and satisfy: .

3. The battery cell according to claim 1, characterized in that, The dimension of the base plate in the third direction is: The third direction is perpendicular to the first direction and the second direction, respectively, and the dimension of the boss in the third direction is [missing information]. , and satisfy: .

4. The battery cell according to claim 1, characterized in that, The wall thickness of the mounting body is The wall thickness of the boss is , and satisfy: .

5. The battery cell according to claim 1, characterized in that, The dimension of the boss in the first direction is: , and satisfy: .

6. The battery cell according to claim 2, characterized in that, The angle at which the first connecting end is inclined relative to the second connecting end toward the interior of the exhaust groove is , satisfy: .

7. The battery cell according to claim 1, characterized in that, The distance between the end faces of the boss and the housing in the second direction is , satisfy: .

8. The battery cell according to any one of claims 1-7, characterized in that, The battery cell also includes an electrode assembly disposed within the receiving space. The electrode assembly includes an electrode group and an insulating film. The electrode group forms two recesses. The recesses are recessed from the end face of the electrode group facing the base plate in the first direction toward the interior of the electrode group. The two recesses are spaced apart along the second direction. The insulating film includes a covered body and an extension connected to each other. The covered body covers the side of the electrode assembly around the perimeter. The extension is respectively attached to the end face of the electrode assembly facing the base plate in the first direction and the inner wall of the two recesses, so that the extension forms two grooves, and the two grooves are respectively connected to the two exhaust grooves.

9. The battery cell according to claim 8, characterized in that, The area of ​​the projection of the electrode assembly onto the projection plane is The dimension of the exhaust groove in the first direction is The dimension of the groove in the first direction is The dimension of the battery cell in the first direction is , , , , and satisfy: .

10. The battery cell according to claim 1, characterized in that, The mounting opening is divided into a first mounting cavity and a second mounting cavity by a partition surface. The two ends of the second mounting cavity in the second direction are respectively connected to the first mounting cavity and the vent groove. The explosion-proof valve is located within the first mounting cavity and abuts against the partition surface. The width of the partition surface is... , satisfy: .

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