Battery cell, battery pack, and electric device

Abstract

The present application relates to the technical field of batteries, and discloses a battery cell, a battery pack, and an electric device. The battery cell has a first direction. The battery cell comprises a casing, an electrode assembly, a top cover assembly, a pressure relief mechanism, an insulating member, and a supporting member. The casing is provided with an accommodating cavity. The casing has a first wall, and the first wall is located at the end of the casing in the first direction. An opening is further formed at the side of the casing distant from the first wall, and the opening is communicated with the accommodating cavity. The pressure relief mechanism is arranged on the first wall. The insulating member is at least partially arranged between the electrode assembly and the first wall. A first weak portion is provided on the insulating member at a position corresponding to the pressure relief mechanism. The supporting member is arranged between the first wall and the insulating member. A second weak portion is provided on the supporting member. The first weak portion and the second weak portion are used for allowing gas to separately pass through the first weak portion and the second weak portion to reach the pressure relief mechanism when thermal runaway occurs in the battery cell. The battery cell provided by the present application has good reliability and safety.

Description

Battery cells, battery packs and electrical devices

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 2024226469310, filed on October 30, 2024, entitled "Battery Cell, Battery Pack and Electrical Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a battery cell, a battery pack, and an electrical device. Background Technology

[0004] New energy batteries are a type of battery technology that uses new energy sources as its power source. They have broad application prospects and significant environmental benefits. With continuous technological advancements and growing market demand, new energy batteries will become an increasingly important technological tool.

[0005] Thermoelectric separation design is becoming increasingly common. Thermoelectric separation design eliminates the pressure relief device on the top cover and places the pressure relief device at the bottom of the shell. However, when the pressure relief device is placed at the bottom of the shell, the bare cell will be pressed tightly against the inner surface of the bottom of the shell due to its own weight, which will cause the pressure relief device port to be blocked. This can easily lead to the inability to release high-temperature gas in time during thermal runaway, or even cause an explosion.

[0006] Application content

[0007] In view of this, this application provides a battery cell, a battery pack, and an electrical device, with the aim of solving one of the technical problems in the prior art.

[0008] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0009] In a first aspect, embodiments of this application provide a battery cell having a first orientation, including:

[0010] The housing has a receiving cavity, and the housing includes a first wall located on one side of the housing along the first direction, and the side of the housing away from the first wall also has an opening communicating with the receiving cavity;

[0011] An electrode assembly is disposed within the accommodating cavity;

[0012] Top cover assembly, sealing the opening;

[0013] A pressure relief mechanism is disposed on the first wall, and the pressure relief mechanism is used to open and relieve pressure when the battery cell experiences thermal runaway.

[0014] An insulating element covers at least a portion of the electrode assembly, the insulating element being at least partially disposed between the electrode assembly and the first wall, and the insulating element having a first weak point corresponding to the position of the pressure relief mechanism;

[0015] A support member is disposed between the first wall and the insulating member, and the support member is provided with a second weak part;

[0016] The first weak portion and the second weak portion are used to allow gas to pass through the first weak portion and the second weak portion respectively and reach the pressure relief mechanism when the battery cell experiences thermal runaway.

[0017] In one embodiment of the first aspect, along the first direction, the orthogonal projection of the second weak portion onto the first wall at least partially falls on the pressure relief mechanism.

[0018] In one embodiment of the first aspect, the insulating member includes two peripheral wall portions and a bottom wall portion. The two peripheral wall portions are respectively disposed on both sides of the bottom wall portion. The bottom wall portion covers the bottom surface of the electrode assembly and corresponds to the first wall. The two peripheral wall portions at least respectively wrap around two opposite sides of the electrode assembly. The first weak portion is disposed on the bottom wall portion.

[0019] In one embodiment of the first aspect, one of the peripheral wall portions includes a first fold, a third fold, and a fourth fold, and the other peripheral wall portion includes a second fold, a fifth fold, and a sixth fold, the two peripheral wall portions enclosing the four sides of the electrode assembly, wherein:

[0020] The first fold and the second fold are spaced apart, and the first fold and the second fold respectively cover one side of the electrode assembly. The third fold is stacked outside the fifth fold and covers the other side of the electrode assembly. The fourth fold is stacked outside the sixth fold and covers the remaining side of the electrode assembly.

[0021] In one embodiment of the first aspect, the third fold and the fourth fold are respectively provided with notches on the side away from the first fold.

[0022] In one embodiment of the first aspect, the bottom wall portion has an indentation groove, and the bottom wall portion also has two opposite sides along the first direction, the indentation groove being disposed on one of the side surfaces, and the indentation groove forming the first weak portion;

[0023] Along the first direction, the thickness of the indentation groove is less than the thickness of the bottom wall portion excluding the first weak portion.

[0024] In one embodiment of the first aspect, the bottom wall portion has a grooved section, and the bottom wall portion also has two opposite sides along the first direction, the grooved section is disposed on one of the side surfaces, and the grooved section forms the first weak portion;

[0025] The etched segment includes a plurality of grooves spaced apart. Along the first direction, the thickness of the grooves is less than the thickness of the bottom wall portion excluding the first weak portion. The plurality of grooves are arranged to form the etched segment.

[0026] In one embodiment of the first aspect, the number of the notched segments is multiple, and the geometric center distance between adjacent grooves in the multiple notched segments is the same.

[0027] In one embodiment of the first aspect, the first weak portion includes a plurality of indentation grooves, and the plurality of indentation grooves are arranged in parallel, intersecting, or enclosing each other to form a closed loop shape.

[0028] In one embodiment of the first aspect, the first weak portion includes a plurality of the notched segments, and the plurality of notched segments are arranged in parallel with each other, intersecting each other, or enclosing each other to form a closed loop shape.

[0029] In one embodiment of the first aspect, the battery cell further has a second direction perpendicular to the first direction, the bottom wall portion extends toward the second direction, and a first through hole is provided on the bottom wall portion, the first through hole penetrating the bottom wall portion along the first direction, and the first through hole and the first weak portion are spaced apart along the second direction.

[0030] In one embodiment of the first aspect, a gap is formed between the periphery of the electrode assembly and the insulating member, and a plurality of the first through holes are arranged on the periphery of the electrode assembly.

[0031] In one embodiment of the first aspect, the number of the first through holes is multiple, and the first through holes are disposed on both sides of the first weak portion along the second direction.

[0032] In one embodiment of the first aspect, the support member has a protruding structure on the side facing the first wall, the protruding structure abutting against the first wall to define an exhaust space between the support member and the first wall; and / or

[0033] The support member is provided with at least one vent hole, which forms the second weak part. All the vent holes penetrate the support member along the first direction, and the orthogonal projection of at least one of the vent holes along the first direction onto the first wall at least partially falls on the pressure relief mechanism.

[0034] In one embodiment of the first aspect, the support member is provided with a second through hole, and along the first direction, the orthographic projection of the second through hole on the bottom wall portion at least partially overlaps with the first through hole, and the second through hole penetrates the support member along the first direction.

[0035] In one embodiment of the first aspect, the support member has a second through hole at the position of each of the first through holes.

[0036] In one embodiment of the first aspect, the support member is further provided with a plurality of third through holes, which are connected to the exhaust space.

[0037] In one embodiment of the first aspect, the first weak portion is located on the side of the bottom wall portion facing the first wall, and / or the first weak portion is located on the side of the bottom wall portion facing the electrode assembly.

[0038] Secondly, embodiments of this application also provide a battery pack, including the battery cells in any of the above embodiments.

[0039] Thirdly, embodiments of this application also provide an electrical device, including the battery pack in any of the above embodiments.

[0040] Compared to existing technologies, the advantages of this application are as follows: This application proposes a battery cell, including a housing, an electrode assembly, a top cover assembly, a pressure relief mechanism, an insulating component, and a supporting component. The housing has a receiving cavity and includes a first wall located on one side of the housing along a first direction. The side of the housing away from the first wall also has an opening communicating with the receiving cavity. The electrode assembly is disposed within the receiving cavity, and the top cover assembly seals the opening. The pressure relief mechanism is disposed on the first wall and is used to release pressure when the battery cell experiences thermal runaway. This achieves the goal of preventing interference between the electrical connection of the electrode assembly and the thermal runaway eruption, thereby improving the reliability and safety of the battery cell.

[0041] An insulating component covers at least a portion of the electrode assembly and is disposed between the electrode assembly and the first wall. The insulating component has a first weak point corresponding to the location of the pressure relief mechanism. Thus, when the battery cell is in normal use, the insulating component insulates the electrode assembly from the casing. When the battery cell experiences thermal runaway, the gas generated within the electrode assembly tears through the first weak point to release pressure.

[0042] The support is located between the first wall and the insulating component. The support has a second weak part. The first weak part and the second weak part are used to allow gas to pass through the first weak part and the second weak part respectively and reach the pressure relief mechanism when the battery cell is thermally runaway. When the battery cell is thermally runaway, the gas rushes through the first weak part and reaches the pressure relief mechanism through the second weak part, so that the battery cell can be smoothly depressurized, thereby improving the reliability and safety of the battery cell. Attached Figure Description

[0043] Figure 1 shows a schematic diagram of the structure of a battery cell in some embodiments of this application;

[0044] Figure 2 shows an exploded structural diagram of a positively positioned battery cell in some embodiments of this application;

[0045] Figure 3 shows an exploded structural diagram of an inverted battery cell in some embodiments of this application;

[0046] Figure 4 shows a schematic diagram of the unfolded structure of the insulating element in some embodiments of this application;

[0047] Figure 5 shows a schematic cross-sectional view of the indentation groove in the AA direction of Figure 4;

[0048] Figure 6 shows a perspective structural diagram of a battery cell in some embodiments of this application;

[0049] Figure 7 shows one of the structural schematic diagrams of the first weak part in some embodiments of this application;

[0050] Figure 8 shows a second schematic diagram of the structure of the first weak part in some embodiments of this application;

[0051] Figure 9 shows a third structural schematic diagram of the first weak part in some embodiments of this application;

[0052] Figure 10 shows a fourth structural schematic diagram of the first weak part in some embodiments of this application;

[0053] Figure 11 shows an enlarged structural schematic diagram of the notched segment at point I in Figure 4. Detailed Implementation

[0054] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0055] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0057] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0058] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] As shown in Figures 1 to 3, an embodiment of this application provides a battery cell 100, which includes a housing 110, an electrode assembly 130, a top cover assembly 140, a pressure relief mechanism 120, an insulating component 150, and a support component 160.

[0060] In this embodiment of the application, the battery cell 100 can be a secondary battery, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0061] The battery cell 100 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0062] In some embodiments, the housing 110 has a receiving cavity 113 and a first wall 111, wherein the first wall 111 is located at one end of the housing 110 along a first direction D1.

[0063] The housing 110 also has an opening 114 located on the side of the housing 110 away from the first wall 111 and communicating with the receiving cavity 113. In this embodiment, as shown in Figures 2 and 3, the first wall 111 is located at the bottom of the electrode assembly 130, and the opening 114 is located at the top of the housing.

[0064] The top cover assembly 140 covers the opening 114, forming a sealed space for accommodating the electrode assembly 130.

[0065] The housing 110 can be made of steel, aluminum, plastic (such as polypropylene), or composite metal (such as copper-aluminum composite). The electrode assembly 130 is disposed within the accommodating cavity 113, and the top cover assembly 140 is electrically connected to the top of the electrode assembly 130.

[0066] The pressure relief mechanism 120 is disposed on the first wall 111 and is used to open the pressure relief mechanism 120 when the battery cell 100 thermally runs away.

[0067] In addition, the pressure relief mechanism 120 is installed on the first wall 111, which also achieves the purpose of preventing the electrical connection of the battery cell 100 and the thermal runaway eruption from interfering with each other, thereby improving the reliability and safety of the battery cell 100.

[0068] The insulating member 150 covers at least a portion of the electrode assembly 130, and specifically the at least portion of the insulating member 150 is disposed between the electrode assembly 130 and the first wall 111, so that an insulating separation is formed between the electrode assembly 130 and the first wall 111 to prevent short circuit.

[0069] It is understandable that if an insulating element 150 is directly placed between the first wall 111 and the electrode assembly 130, although the short circuit problem between the first wall 111 and the electrode assembly 130 can be solved, the insulating element 150 will block the gas flow to the pressure relief mechanism 120, so that the battery cell 100 cannot be depressurized when it thermally runs away.

[0070] To address the aforementioned issues, as shown in Figures 2 and 3, a first weak point 1521 is provided on the insulating component 150 at the position corresponding to the pressure relief mechanism 120. When the battery cell 100 is in normal use, the insulating component 150 insulates the electrode assembly 130 from the first wall 111. When the battery cell 100 experiences thermal runaway, the strength at the location of the first weak point 1521 is relatively low. The gas generated within the electrode assembly 130 tears the first weak point 1521 to release pressure, thereby reducing the risk of the battery cell 100 exploding or catching fire.

[0071] Thermal runaway of a single battery cell 100 refers to the internal pressure or temperature of a single battery cell 100 reaching the explosion pressure.

[0072] As shown in Figure 6, a support member 160 is also disposed between the first wall 111 and the insulating member 150, separating the insulating member 150 from the pressure relief mechanism 120. The support member 160 is also provided with a second weak point 161. When the battery cell 100 experiences thermal runaway, the gas rushes through the first weak point 1521. The first weak point 1521 and the second weak point 161 allow gas to pass through the first weak point 1521 and the second weak point 161 respectively and reach the pressure relief mechanism 120 during thermal runaway of the battery cell 100, thus facilitating pressure relief of the battery cell 100 and improving its reliability and safety.

[0073] In some embodiments, along the first direction D1, the orthographic projection of the second weak portion 161 on the first wall 111 at least partially falls on the corresponding pressure relief mechanism 120. This ensures that the first weak portion 1521 and the second weak portion 161 are sequentially corresponding to the pressure relief mechanism 120. When the battery cell 100 experiences thermal runaway, the first weak portion 1521, the second weak portion 161, and the pressure relief mechanism 120 are sequentially connected, allowing gas to be rapidly released to the outside, shortening the gas flow path, reducing the pressure relief time, and improving the pressure relief efficiency.

[0074] In some embodiments, as shown in FIG4, the insulating member 150 further includes two peripheral wall portions 151 and a bottom wall portion 152.

[0075] The bottom wall portion 152 covers the bottom surface of the electrode assembly 130 and corresponds to the first wall 111.

[0076] The first weak part 1521 is provided on the bottom wall part 152, so that the position of the first weak part 1521 corresponds to that of the pressure relief mechanism 120.

[0077] Two peripheral wall portions 151 are respectively provided on both sides of the bottom wall portion 152, and the peripheral wall portions 151 at least cover the two opposite sides of the electrode assembly 130.

[0078] In this embodiment, as shown in FIG3, two peripheral wall portions 151 enclose the four sides of the electrode assembly 130 (front, rear, left, and right), improving the safety of the battery cell 100. In other embodiments, the peripheral wall portions 151 enclose the front and rear sides or the left and right sides of the electrode assembly 130.

[0079] In this embodiment, as shown in FIG4, one of the peripheral wall portions 151 includes a first fold portion 1511, a third fold portion 1513 and a fourth fold portion 1514, and the other peripheral wall portion 151 includes a second fold portion 1512, a fifth fold portion 1515 and a sixth fold portion 1516.

[0080] When the insulating member 150 is unfolded, the first fold 1511 and the second fold 1512 are spaced apart along the third direction D3 and are respectively connected to the edge of the bottom wall portion 152.

[0081] The third fold portion 1513 and the fourth fold portion 1514 are spaced apart along the second direction D2, and the third fold portion 1513 and the fourth fold portion 1514 are respectively connected to the edge of the first fold portion 1511.

[0082] The fifth fold portion 1515 and the sixth fold portion 1516 are spaced apart along the second direction D2, and the fifth fold portion 1515 and the sixth fold portion 1516 are respectively connected to the edge of the second fold portion 1512.

[0083] The two peripheral wall portions 151 have the same shape, except that the third fold portion 1513 and the fourth fold portion 1514 are respectively provided with notches on the side away from the first fold portion 1511. This design facilitates the uniformity of the assembly method of the insulating component 150, so that the third fold portion 1513 of the insulating component 150 is outside the fifth fold portion 1515 and the fourth fold portion 1514 is outside the sixth fold portion 1516.

[0084] As shown in Figures 3 and 4, when the insulating member 150 is assembled, the electrode assembly 130 is housed within the insulating member 150. The bottom wall portion 152 covers the bottom surface of the electrode assembly 130, the second fold portion 1512 covers the front side of the electrode assembly 130, the first fold portion 1511 covers the rear side of the electrode assembly 130, the third fold portion 1513 and the fifth fold portion 1515 are stacked and cover the right side of the electrode assembly 130, and the fourth fold portion 1514 and the sixth fold portion 1516 are stacked and cover the left side of the electrode assembly 130.

[0085] It should be noted that the battery cell 100 has a first direction D1, a second direction D2 and a third direction D3, wherein the first direction D1 is the thickness direction of the bottom wall portion 152, the second direction D2 is the length direction of the bottom wall portion 152, and the third direction D3 is the width direction of the bottom wall portion 152. The first direction D1, the second direction D2 and the third direction D3 are perpendicular to each other.

[0086] In some embodiments, as shown in Figures 4 and 5, the bottom wall portion 152 has an indentation groove 1522.

[0087] Indentation groove 1522 refers to the indentation mark formed by applying pressure to the surface of a material, causing the material to deform.

[0088] The bottom wall portion 152 also has two opposite sides along the first direction D1, and an indentation groove 1522 is provided on one of the side surfaces, forming a first weak portion 1521.

[0089] It should be understood that the thickness of the indentation groove 1522 is less than the thickness of the bottom wall portion 152 excluding the first weak portion 1521, making the structural strength at the indentation groove 1522 on the bottom wall portion 152 lower than that of the portion excluding the first weak portion 1521. When the battery cell 100 experiences thermal runaway, the gas preferentially breaks through the indentation groove 1522, allowing the gas to release pressure through the first weak portion 1521, and also guiding the gas.

[0090] The indentation groove 1522 is typically created using tools such as an indentation tool, a roller, or an impression plate. The indentation groove 1522 extends continuously along the bottom wall portion 152, which improves the processing efficiency of the indentation groove 1522 and reduces the requirements for processing tools.

[0091] In some embodiments, the number of indentation grooves 1522 is at least one.

[0092] In some embodiments, the thickness of the indentation groove 1522 is T, which satisfies: 0.01mm≤T≤0.3mm. T represents the residual thickness of the bottom wall portion 152 at the indentation groove 1522. When there are multiple indentation grooves 1522, the thicknesses of the multiple indentation grooves 1522 can be the same or different.

[0093] In this embodiment, the thickness of the multiple indentation grooves 1522 is the same. The thickness of the indentation grooves 1522 can be T = 0.01mm, 0.05mm, 0.1mm, 0.45mm, 0.2mm, 0.25mm, 0.3mm, etc. When T < 0.01mm, the bottom wall portion 152 of the insulating component 150 is prone to tearing and damage during the manufacturing process, reducing the product qualification rate; when T > 0.3mm, the bottom wall portion 152 of the insulating component 150 is not easily torn at the weak part 1521 under internal pressure impact, and pressure cannot be released in time.

[0094] In some embodiments, as shown in Figures 4 and 11, the bottom wall portion 152 has a grooved section 1524.

[0095] The notched section 1524 is formed by machining with a toothed cutter. It can be understood that the toothed cutter has a serrated cutting edge, and when the toothed cutter presses on the material surface, the material surface is left with a notched section 1524 consisting of multiple grooves 15241.

[0096] In some embodiments, the number of notched segments 1524 is at least one.

[0097] The bottom wall portion 152 also has two opposite sides along the first direction D1, and a grooved section 1524 is provided on one of the sides, and the grooved section 1524 forms a first weak portion 1521.

[0098] The etched segment 1524 includes a plurality of spaced grooves 15241. Along the first direction D1, the thickness of the grooves 15241 is less than the thickness of the bottom wall portion 152 excluding the first weak portion 1521. The thickness of the etched segment 1524 is the residual thickness of the bottom wall portion 152 at the etched segment 1524. The plurality of grooves 15241 are arranged sequentially to form the etched segment 1524.

[0099] It should be understood that, since the two grooves 15241 of the etched section 1524 are spaced apart, the connecting part between the two grooves 15241 forms a reinforcing rib structure. In this way, the etched section 1524 is not easily damaged when the battery cell 100 is in normal use, thus improving the safety and reliability of the battery cell 100.

[0100] In some embodiments, as shown in FIG11, the groove 15241 has a geometric center, and the distance between the geometric centers of adjacent grooves 15241 is D, which satisfies: 0.5mm≤D≤5mm. When there are multiple score segments 1524, the center distance between adjacent grooves 15241 in the multiple score segments 1524 can be the same or different.

[0101] In this embodiment, the geometric center distance between adjacent grooves 15241 in the multiple scribed segments 1524 is the same. The value of the geometric center distance between adjacent grooves 15241 in the scribed segment 1524 can be: D = 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc. When D < 0.5mm, the bottom wall portion 152 of the insulating component 150 is prone to tearing and damage during the manufacturing process, reducing the product qualification rate; when T > 5mm, the bottom wall portion 152 of the insulating component 150 is not easily torn at the weak part 1521 under internal pressure impact, and pressure cannot be released in time.

[0102] In some embodiments, the first weak portion 1521 includes a plurality of indentation grooves, and each indentation groove 1522 is arranged in parallel with each other, intersecting each other, or enclosing each other to form a closed loop shape.

[0103] In some embodiments, the first weak portion 1521 includes a plurality of etched segments 1524, and each etched segment 1524 is arranged in parallel with each other, intersecting each other, or enclosing each other to form a closed loop shape.

[0104] For example, as shown in Figure 10, the indentation groove 1522 or the scoring segment 1524 is straight, and the two indentation grooves 1522 or the two scoring segments 1524 are arranged parallel to each other along the third direction D3. It can be understood that the indentation groove 1522 or the scoring segment 1524 can also be curved, and three, four, or other numbers of indentation grooves 1522 or scoring segments 1524 can also be arranged parallel to each other along the third direction D3.

[0105] For example, as shown in Figures 7 and 8, the indentation groove 1522 or the scoring segment 1524 is straight, and two indentation grooves 1522 or two scoring segments 1524 intersect to form a cross shape or an X shape. It can be understood that the indentation groove 1522 or the scoring segment 1524 can also be curved, and three, four, or other numbers of indentation grooves 1522 or scoring segments 1524 can also be intersect to form an I-shape, a mesh, or other structures.

[0106] For example, as shown in Figure 9, the indentation groove 1522 is straight or curved, the scoring segment 1524 is straight or curved, and multiple indentation grooves 1522 or multiple scoring segments 1524 form a closed loop shape.

[0107] A closed-loop shape refers to a planar shape with closed edges. For example, the closed-loop shape may be the same as the outer periphery structure of the pressure relief mechanism 120. Alternatively, the closed-loop structure can be elliptical, rectangular, or crisscross-shaped. The specific structure of the closed-loop shape can be customized according to requirements.

[0108] In some embodiments, the bottom wall portion 152 extends toward the second direction D2, and a plurality of first through holes 1523 are provided on the bottom wall portion 152. The first through holes 1523 penetrate the bottom wall portion 152 along the first direction D1. The first through holes 1523 and the first weak portion 1521 are spaced apart along the second direction D2. The first through holes 1523 are used to discharge gas inside the insulating member 150.

[0109] In some embodiments, a gap is formed between the periphery of the electrode assembly 130 and the insulating member 150, and a plurality of first through holes 1523 are also arranged on the periphery of the electrode assembly 130 to facilitate the discharge of gas between the periphery of the electrode assembly 130 and the insulating member 150. There are multiple first through holes 1523, and the first through holes 1523 are disposed on both sides of the first weak portion 1521 along the second direction D2.

[0110] As shown in Figure 6, in this embodiment, three first through holes 1523 are respectively provided on both sides of the electrode assembly 130, and the three first through holes 1523 are spaced apart along a third direction D3. In other embodiments, the number and size of the first through holes 1523 can be set as needed.

[0111] In some embodiments, the support member 160 has a protrusion structure 164 on the side facing the first wall 111, the protrusion structure 164 abutting against the first wall 111 to define an exhaust space 170 between the support member 160 and the first wall 111; and / or, the support member 160 is provided with at least one exhaust hole 1611, the at least one exhaust hole 1611 forming a second weak portion 161.

[0112] The vent 1611 extends through the support 160 along the first direction D1, and the orthogonal projection of the vent 1611 along the first direction D1 on the first wall 111 at least partially falls within the pressure relief mechanism 120.

[0113] A pressure relief hole 1111 is provided on the first wall 111, a pressure relief mechanism 120 is provided in the pressure relief hole 1111, and an exhaust hole 1611 is connected to the pressure relief mechanism 120.

[0114] In some embodiments, the support member 160 is further provided with a second through hole 162. Along the first direction D1, the orthographic projection of the second through hole 162 on the bottom wall portion 152 at least partially overlaps with the first through hole 1523. The second through hole 162 extends through the support member 160 along the first direction D1. When the battery cell 100 is in normal use, the gas inside the insulating member 150 flows to the pressure relief mechanism 120 through the first through hole 1523 and the second through hole 162.

[0115] The second through hole 162 and the exhaust hole 1611 are spaced apart along the second direction D2. The second through hole 162 connects the first through hole 1523 and the exhaust space 170.

[0116] In this embodiment, there is one vent hole 1611. The vent hole 1611 and the first weak part 1521 are positioned opposite each other. In the first direction D1, the projection of the first weak part 1521 is located inside the vent hole 1611, so that when the battery cell 100 thermally runs away, all the indentation grooves 1522 or the scoring segments 1524 can be completely cracked to release pressure smoothly.

[0117] In other embodiments, there are multiple vent holes 1611, and the size and shape of each vent hole 1611 are set according to the specific shape of the first weak part 1521. For example, as shown in FIG7, the first weak part 1521 is cross-shaped, and the vent hole 1611 can also be set to a cross shape accordingly; for example, as shown in FIG8, the first weak part 1521 is X-shaped, and the vent hole 1611 can also be set to an X shape accordingly; for example, as shown in FIG10, the first weak part 1521 includes two indentation grooves 1522, and there are two vent holes 1611, with one vent hole 1611 corresponding to one indentation groove 1522.

[0118] As shown in Figure 6, in this embodiment, the support member 160 has a second through hole 162 at the position corresponding to each first through hole 1523 to facilitate smooth exhaust.

[0119] In some embodiments, as shown in Figures 2 and 3, the support member 160 is also provided with a plurality of third through holes 163, which are connected to the exhaust space 170 and are used to discharge gas inside the housing 110.

[0120] In some embodiments, the first weak portion 1521 is provided on the side of the bottom wall portion 152 facing the first wall 111, and / or the first weak portion 1521 is provided on the side of the bottom wall portion 152 facing the electrode assembly 130.

[0121] When the first weak part 1521 is located on the side of the bottom wall 152 near the first wall 111 or on the side of the bottom wall 152 near the electrode assembly 130, the processing steps of the insulating part 150 can be simplified, and the front and back of the insulating part 150 can be quickly distinguished when assembling the insulating part 150, thereby improving assembly efficiency.

[0122] Wherein, when the first weak part 1521 is located on the side of the bottom wall 152 near the first wall 111, and when the first weak part 1521 is located on the side of the bottom wall 152 near the electrode assembly 130, the indentation grooves 1522 and the scoring segments 1524 on both sides are staggered and do not overlap, so as to avoid the bottom wall 152 from being easily torn or damaged during the manufacturing process.

[0123] This application also provides a battery, including the battery cell 100 of any of the above embodiments. Since it includes the battery cell 100 of any of the above embodiments, it possesses all the beneficial effects of the battery cell 100 of any of the above embodiments, which will not be elaborated further here.

[0124] This application also provides an electrical device, including the battery cell 100 in any of the above embodiments or the battery in any of the above embodiments.

[0125] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0126] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0127] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0128] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A battery cell having a first orientation (D1), characterized in that, include: The housing (110) has a receiving cavity (113) and the housing (110) has a first wall (111) located on one side of the housing (110) along the first direction (D1). The housing (110) also has an opening (114) on the side away from the first wall, and the opening (114) communicates with the receiving cavity (113). An electrode assembly (130) is disposed within the accommodating cavity (113); A top cover assembly (140) covers the opening (114); A pressure relief mechanism (120) is disposed on the first wall (111), and the pressure relief mechanism (120) is used to open and relieve pressure when the battery cell (100) experiences thermal runaway; An insulating member (150) covers at least a portion of the electrode assembly (130), the insulating member (150) is at least partially disposed between the electrode assembly (130) and the first wall (111), and the insulating member (150) has a first weak portion (1521) at the position corresponding to the pressure relief mechanism (120); A support member (160) is disposed between the first wall (111) and the insulating member (150), and the support member (160) is provided with a second weak part (161); The first weak portion (1521) and the second weak portion (161) are used to allow gas to pass through the first weak portion (1521) and the second weak portion (161) respectively and reach the pressure relief mechanism (120) when the battery cell (100) experiences thermal runaway.

2. The battery cell according to claim 1, characterized in that, Along the first direction (D1), the orthographic projection of the second weak portion (161) onto the first wall (111) at least partially falls on the pressure relief mechanism (120).

3. The battery cell according to claim 1, characterized in that, The insulating member (150) includes two peripheral wall portions (151) and a bottom wall portion (152). The two peripheral wall portions (151) are respectively disposed on both sides of the bottom wall portion (152). The bottom wall portion (152) covers the bottom surface of the electrode assembly (130) and corresponds to the first wall (111). The two peripheral wall portions (151) respectively cover at least two opposite sides of the electrode assembly (130). The first weak portion (1521) is disposed on the bottom wall portion (152).

4. The battery cell according to claim 3, characterized in that, One of the peripheral wall portions (151) includes a first fold (1511), a third fold (1513), and a fourth fold (1514), and the other peripheral wall portion (151) includes a second fold (1512), a fifth fold (1515), and a sixth fold (1516). The two peripheral wall portions (151) enclose the four sides of the electrode assembly (130), wherein: The first fold (1511) and the second fold (1512) are spaced apart, and the first fold (1511) and the second fold (1512) respectively cover one side of the electrode assembly (130). The third fold (1513) is stacked outside the fifth fold (1515) and covers the other side of the electrode assembly (130). The fourth fold (1514) is stacked outside the sixth fold (1516) and covers the remaining side of the electrode assembly (130).

5. The battery cell according to claim 4, characterized in that, The third fold (1513) and the fourth fold (1514) are respectively provided with notches on the side away from the first fold (1511).

6. The battery cell according to claim 3, characterized in that, The bottom wall portion (152) has an indentation groove (1522), and the bottom wall portion (152) also has two opposite sides along the first direction (D1). The indentation groove (1522) is disposed on one of the side surfaces, and the indentation groove (1522) forms the first weak portion (1521). Along the first direction (D1), the thickness of the indentation groove (1522) is less than the thickness of the bottom wall portion (152) excluding the first weak portion (1521).

7. The battery cell according to claim 3, characterized in that, The bottom wall portion (152) has a serrated section (1524), and the bottom wall portion (152) also has two opposite sides along the first direction (D1), the serrated section (1524) is disposed on one of the side surfaces, and the serrated section (1524) forms the first weak portion (1521); The etched segment (1524) includes a plurality of spaced grooves (15241). Along the first direction (D1), the thickness of the grooves (15241) is less than the thickness of the bottom wall portion (152) excluding the first weak portion (1521). The plurality of grooves (15241) are arranged to form the etched segment (1524).

8. The battery cell according to claim 7, characterized in that, The number of the etched segments (1524) is multiple, and the geometric center distance between adjacent grooves (15241) in the multiple etched segments (1524) is the same.

9. The battery cell according to claim 4, characterized in that, The first weak part (1521) includes a plurality of indentation grooves (1522), and the plurality of indentation grooves (1522) are arranged in parallel, intersecting or enclosing each other to form a closed loop shape.

10. The battery cell according to claim 5, characterized in that, The first weak part (1521) includes a plurality of the notched segments (1524), and the plurality of notched segments (1524) are arranged in parallel, intersecting or enclosing each other to form a closed loop shape.

11. The battery cell according to any one of claims 3 to 10, characterized in that, The battery cell (100) also has a second direction (D2) which is perpendicular to the first direction (D1). The bottom wall portion (152) extends toward the second direction (D2), and a first through hole (1523) is provided on the bottom wall portion (152). The first through hole (1523) penetrates the bottom wall portion (152) along the first direction (D1), and the first through hole (1523) and the first weak portion (1521) are spaced apart along the second direction (D2).

12. The battery cell according to claim 11, characterized in that, A gap is formed between the periphery of the electrode assembly (130) and the insulating member (150), and a plurality of first through holes (1523) are arranged on the periphery of the electrode assembly (130).

13. The battery cell according to claim 11, characterized in that, The number of the first through holes (1523) is multiple, and the first through holes (1523) are disposed on both sides of the first weak part (1521) along the second direction (D2).

14. The battery cell according to claim 11, characterized in that, The support member (160) has a protruding structure (164) on the side facing the first wall (111), the protruding structure (164) abutting against the first wall (111) to define an exhaust space (170) between the support member (160) and the first wall (111); and / or The support member (160) is provided with at least one vent hole (1611), the vent hole (1611) forms the second weak part (161), the vent holes (1611) all penetrate the support member (160) along the first direction (D1), and at least one of the vent holes (1611) has its orthographic projection along the first direction (D1) onto the first wall (111) at least partially falling on the pressure relief mechanism (120).

15. The battery cell according to claim 14, characterized in that, The support member (160) is provided with a second through hole (162). Along the first direction (D1), the orthographic projection of the second through hole (162) on the bottom wall portion (152) overlaps at least partially with the first through hole (1523), and the second through hole (162) penetrates the support member (160) along the first direction (D1).

16. The battery cell according to claim 15, characterized in that, The support member (160) has a second through hole (162) at each position of the first through hole (1523).

17. The battery cell according to claim 15, characterized in that, The support member (160) is also provided with a plurality of third through holes (163), which are connected to the exhaust space (170).

18. The battery cell according to claim 3, characterized in that, The first weak portion (1521) is provided on the side of the bottom wall portion (152) facing the first wall (111), and / or the first weak portion (1521) is provided on the side of the bottom wall portion (152) facing the electrode assembly (130).

19. A battery pack, characterized in that, Includes the battery cell (100) according to any one of claims 1 to 18.

20. An electrical device, characterized in that, Includes the battery pack as described in claim 19.

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