Battery monomer, battery pack, power utilization device and energy storage device

Abstract

The utility model discloses a single battery, a battery pack, a power utilization device and an energy storage device, and belongs to the technical field of batteries, and the single battery comprises a shell, an anti-explosion valve, a naked battery cell and an elastic piece. The explosion-proof valve is arranged in the shell, the naked battery cell is arranged in the shell, and the arrangement direction of the explosion-proof valve and the naked battery cell is a first direction. The elastic piece is located between the naked battery cell and the shell wall, facing one side of the anti-explosion valve in the first direction, of the shell in the first direction. According to the embodiment of the invention, the elastic piece is arranged between the naked battery cell and the shell wall, facing one side of the anti-explosion valve, of the shell along the first direction. When thermal runaway occurs in the single battery, the naked battery core is driven by airflow so as to move towards the explosion-proof valve along the first direction. And the elastic piece can play a certain buffering role on the naked battery cell, so that the rigid impact on the naked battery cell is reduced, and the condition of short circuit caused by deformation of the naked battery cell due to external load is relieved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery cells, battery units, battery packs and electrical devices. Background Art

[0002] New energy batteries are being used more and more widely in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also being increasingly used in areas such as energy storage.

[0003] In the related art, when a battery cell experiences thermal runaway, the battery cell may short-circuit. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a battery cell, a battery pack and an electrical device to alleviate the short circuit situation of the battery cell.

[0005] This application is implemented through the following technical solutions.

[0006] A first aspect of an embodiment of the present application provides a battery cell, including:

[0007] shell;

[0008] An explosion-proof valve, arranged on the housing;

[0009] A bare battery cell is disposed in the housing, and the explosion-proof valve and the bare battery cell are arranged in a first direction;

[0010] An elastic member, wherein the elastic member is located along the first direction between the bare battery core and a shell wall of the shell along the first direction toward the explosion-proof valve.

[0011] In the solution of the embodiment of the present application, an elastic member is provided along the first direction between the bare cell and the shell wall of the shell along the first direction facing the explosion-proof valve. When thermal runaway occurs inside the battery cell, the bare cell will be driven by the airflow and thus rush toward the explosion-proof valve along the first direction. The elastic member can play a certain buffering role on the bare cell, reduce the rigid impact on the bare cell, and thus alleviate the situation where the bare cell is deformed due to external loads and causes short circuit.

[0012] In one embodiment, the battery cell further includes an insulating member, wherein the insulating member is located between the bare cell and a shell wall of the shell along the first direction toward the explosion-proof valve, and the elastic member is at least partially located along the first direction on a side of the insulating member toward the bare cell.

[0013] In the solution of the embodiment of the present application, the battery cell further includes an insulating member, which is located between the bare cell and the shell wall of the shell along the first direction toward the explosion-proof valve. The insulating member can alleviate the short circuit between the bare cell and the shell, and the insulating member can reduce the rigid collision between the bare cell and the shell to a certain extent, thereby further reducing the short circuit of the bare cell.

[0014] In one embodiment, the insulating member is formed with a first protrusion, the first protrusion protrudes toward the bare battery cell along the first direction, and the elastic member is connected to a side of the first protrusion facing the bare battery cell.

[0015] In the solution of the embodiment of the present application, the insulating member is formed with a first protrusion, and the first protrusion protrudes toward the bare cell along the first direction. The first protrusion can increase the size of the insulating member along the first direction, and the insulating member can abut against the bare cell through the first protrusion, thereby pressing the bare cell to reduce the movement of the bare cell along the first direction during the operation of the battery cell.

[0016] In one embodiment, the first protrusion forms an avoidance cavity, the tab of the bare battery cell is located in the avoidance cavity, the first protrusion is arranged circumferentially around the tab, and the elastic member is annular and surrounds the tab.

[0017] In the solution of the embodiment of the present application, the first bump is formed with an avoidance cavity, the tab of the bare cell is located in the avoidance cavity, the elastic member is annular, and the elastic member surrounds the tab. The first bump is formed with an avoidance cavity to avoid the tab of the bare cell and reduce the situation where the tab is pressed by the insulating member. The elastic member surrounding the tab can make full use of the space around the tab, maximize the contact area between the elastic member and the bare cell, thereby increasing the buffering effect of the elastic member and further reducing the situation where the bare cell short circuit occurs.

[0018] In one embodiment, the number of the elastic members is two, and the two elastic members are respectively located on both sides of the insulating member along the second direction, and the second direction is arranged to cross the first direction.

[0019] In the embodiment of the present application, there are two elastic members, and the two elastic members are respectively located on both sides of the insulating member. The spacing arrangement of the elastic members can balance the blocking effect of the elastic members on the bare battery cell, so that the bare battery cell is subjected to a more uniform force.

[0020] In one embodiment, a mounting groove is formed on a side of the elastic member facing the insulating member, an opening of the mounting groove faces the insulating member, and the insulating member is partially located in the mounting groove.

[0021] In the embodiment of the present application, a mounting groove is formed on one side of the elastic member facing the insulating member, and the opening of the mounting groove faces the insulating member. The insulating member can be connected to the elastic member through the mounting groove, so that the insulating member and the elastic member are connected as one body, which can alleviate the shaking of the elastic member inside the battery cell to a certain extent, and the elastic member can more stably buffer the bare battery cell during operation.

[0022] In one embodiment, along the arrangement direction of the explosion-proof valve and the bare battery cell, the size of the elastic member is a target size, the range of the target size is 0.5 mm to 5.0 mm, the contact area between the elastic member and the bare battery cell is a first area, the area of ​​the projection area of ​​the bare battery cell in the arrangement direction of the explosion-proof valve and the bare battery cell is a second area, the units of the first area and the second area are the same, the ratio of the first area to the second area is a first ratio, and the range of the first ratio is 5.1% to 44.7%.

[0023] In the embodiment of the present application, the target size and the first ratio are within a suitable range, so that the size of the elastic member can be as small as possible while providing a certain buffering effect, thereby increasing the size of the bare battery cell along the length direction and increasing the energy density of the battery cell.

[0024] In one embodiment, along the arrangement direction of the explosion-proof valve and the bare battery cell, the size of the elastic member is a target size, the range of the target size is 0.5 mm to 5.0 mm, and the valve opening pressure of the explosion-proof valve is a target pressure, the range of the target pressure is 0.5 MPa to 5.5 MPa.

[0025] In the embodiment of the present application, the magnitude of the target pressure can control the load on the bare cell when it rushes to the explosion-proof valve in the event of thermal runaway. The target pressure within a suitable range can enable the elastic member to buffer the bare cell more stably, and further alleviate the situation where the explosion-proof valve is opened by the gas generated by the bare cell in normal operation.

[0026] In one embodiment, the elastic modulus of the elastic member is greater than or equal to 0.1 MPa and less than or equal to 1000 MPa.

[0027] In the embodiment of the present application, the elastic modulus of the elastic member can be within a suitable range so that the deformation of the elastic member is as small as possible when buffering the bare battery cell, thereby reducing the size of the elastic member along the first direction and reducing the size of the battery cell along the first direction.

[0028] In one embodiment, the elastic modulus of the elastic member is greater than or equal to 0.5 MPa and less than or equal to 100 MPa.

[0029] In the embodiment of the present application, the elastic modulus of the elastic member can further increase the buffering effect of the elastic member on the bare battery cell within a smaller range, and can control the deformation of the elastic member within an appropriate range.

[0030] In one embodiment, the outer shell includes a top cover and a shell connected to each other, the top cover is arranged on the shell, the explosion-proof valve is arranged on the top cover, one of the elastic member and the top cover is formed with a second protrusion, and the other is formed with a positioning groove, and the second protrusion is at least partially located in the positioning groove to install the elastic member.

[0031] In the embodiment of the present application, a second protrusion and a positioning groove that can cooperate with each other are formed between the top cover and the elastic member. The cooperation between the second protrusion and the positioning groove can quickly install the elastic member, and can play a certain role in limiting the elastic member, thereby alleviating the shaking of the elastic member inside the battery cell.

[0032] In one embodiment, the elastic member is made of insulating material.

[0033] In the embodiment of the present application, the elastic member is made of insulating material, which can reduce the short circuit of the battery cell during use. The elastic member can replace the insulating member to alleviate the short circuit between the bare cell and the shell, thereby reducing the number of components inside the battery cell.

[0034] In one embodiment, the elastic member includes an elastic member body and a protective layer that are interconnected, the protective layer is coated on the elastic member body, the protective layer includes an insulating layer and / or an anti-corrosion layer, and the anti-corrosion layer is used to inhibit the elastic member body from being corroded by the electrolyte.

[0035] In the embodiment of the present application, the elastic member has a multi-layer structure, and the protective layer can, to a certain extent, alleviate the situation where the bare battery cell directly contacts the external metal, thereby causing a short circuit, or the situation where the elastic member is corroded by the electrolyte.

[0036] A second aspect of the present application provides a battery pack, comprising:

[0037] Box;

[0038] Any of the above-mentioned battery cells is arranged inside the box.

[0039] A third aspect of an embodiment of the present application provides an electrical device, including:

[0040] Device body;

[0041] The battery pack described in any of the above items is used to supply power to the device body.

[0042] A fourth aspect of an embodiment of the present application provides an energy storage device, comprising:

[0043] Install the container;

[0044] The battery pack described in any of the above items is arranged in the installation container.

[0045] Effect of the invention:

[0046] In the solution of the embodiment of the present application, an elastic member is provided along the first direction between the bare cell and the shell wall of the shell along the first direction facing the explosion-proof valve. When thermal runaway occurs inside the battery cell, the bare cell will be driven by the airflow and thus rush toward the explosion-proof valve along the first direction. The elastic member can play a certain buffering role on the bare cell, reduce the rigid impact on the bare cell, and thus alleviate the situation where the bare cell is deformed due to external loads and causes short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0048] Figure 1 It is a structural explosion diagram of a battery cell according to the first embodiment of the present application;

[0049] Figure 2 It is a schematic diagram of assembling the elastic member and the insulating member of the second embodiment of the present application;

[0050] Figure 3 It is a schematic diagram of assembling the elastic member and the insulating member of the third embodiment of the present application;

[0051] Figure 4 A schematic structural diagram of a battery cell according to a fourth embodiment of the present application;

[0052] Figure 5 for Figure 4 A partial enlarged view of the middle position A;

[0053] Figure 6 It is a structural explosion diagram of a battery cell according to a fifth embodiment of the present application;

[0054] Figure 7 A schematic structural diagram of a battery cell according to a sixth embodiment of the present application;

[0055] Figure 8 for Figure 7 A partial enlarged view of position B in the middle.

[0056] Description of Reference Numerals

[0057] 1. Shell; 10. Top cover; 10a. Positioning groove; 11. Shell; 2. Explosion-proof valve; 3. Bare battery cell; 3a. First direction; 4. Elastic member; 4a. Second direction; 4b. Mounting groove; 4c. Second bump; 5. Insulating member; 5a. First bump; 5b. Avoidance cavity. DETAILED DESCRIPTION

[0058] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0060] In the description of the embodiments of the present application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0061] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0062] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0063] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "top", "bottom", "upper", and "lower" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description. They do not indicate or imply that the referred device or element must have a specific orientation, be constructed, operated, or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0064] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0065] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and may be direct contact or contact through an intermediate medium layer. It may be contact with essentially no interaction force between the two contacting parties, or it may be contact with interaction force between the two contacting parties.

[0066] In the related art, the shell of the battery cell is provided with an explosion-proof valve. When the battery cell has thermal runaway, the gas inside the battery cell can flow to the outside through the explosion-proof valve, thereby alleviating the situation where the battery cell is damaged due to excessive internal air pressure. However, in the case of thermal runaway of the battery cell, the internal gas will drive the bare cell to move toward the explosion-proof valve, causing the bare cell to collide with a harder object. The pole piece of the bare cell may be deformed due to external impact, so that the positive pole piece and the negative pole piece are short-circuited, causing the battery cell to short-circuit. For stacked cells or wound cells, an isolation film is provided between the positive pole piece and the negative pole piece of the cell to avoid short-circuiting between the negative pole piece and the positive pole piece. When the bare cell is subjected to external impact, the isolation film may be torn, causing short-circuiting between the positive pole piece and the negative pole piece, so that the bare cell short-circuits.

[0067] Exemplarily, a collision occurs between the bare battery cell 3 and the insulating member 5 .

[0068] It is understandable that the bare battery cell 3 may collide not only with the insulating member 5 , but also with other harder objects.

[0069] In the present application, an elastic member 4 is disposed between the shell wall where the explosion-proof valve 2 is located and the bare battery cell 3 to buffer the bare battery cell 3 , thereby alleviating the situation where the bare battery cell 3 is short-circuited.

[0070] The solution of the embodiments of the present application can be applied to, but is not limited to, a battery pack including a battery cell or a battery unit, and can also be applied to an electrical device including a battery cell and a battery pack.

[0071] The present application provides an electrical device, which includes a device body and a battery pack, and the battery pack is used to supply power to the device body.

[0072] An electric device is a device that uses electric energy as energy and realizes corresponding functions by consuming electric energy. For example, the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0073] The main body of the device refers to the main structure that consumes electric energy to achieve the corresponding function. For example, the power-consuming device can be a mobile phone, and the main body of the device is the part that can achieve functions such as communication, and the battery cell or battery pack supplies power to the part that can achieve functions such as communication. For example, the power-consuming device can be a car, and the main body of the device is the part that can be used for people to sit and can be driven on the road, and the battery cell or battery pack supplies power to the part that can be used for people to sit and can be driven on the road.

[0074] A battery pack refers to a device that can output electric energy. For example, electric energy can be output by a battery pack composed of battery cells. For example, electric energy can be output by a battery module composed of battery cells and a battery pack composed of battery modules.

[0075] The electrical device of an embodiment of the present application is taken as an example of a vehicle.

[0076] The vehicle provided in one embodiment of the present application may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery pack is provided inside the vehicle, and the battery pack may be provided at the bottom, head or tail of the vehicle. The battery pack may be used to power the vehicle, for example, the battery pack may be used as an operating power source for the vehicle. The vehicle may also include a controller and a motor, and the controller may be used to control the battery pack to power the motor. For example, the battery pack may be used for starting, navigating and operating power requirements of the vehicle during driving.

[0077] In some embodiments of the present application, the battery pack can be used not only as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0078] The present application also provides a battery pack, which includes a box body and a battery cell, wherein the battery cell is arranged inside the box body.

[0079] The present application also provides a battery unit, which includes at least two battery cells and one or at least two bars. The bars are electrically connected to two different battery cells, respectively. Exemplarily, the number of battery cells can be multiple, and the multiple battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that multiple battery cells are both connected in series and in parallel. Multiple battery cells can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells is placed in a box. Of course, multiple battery cells can be first connected in series, in parallel, or in mixed connection to form a battery module, and the multiple battery modules are then connected in series, in parallel, or in mixed connection to form a whole, and the whole formed by the multiple battery modules connected in series, in parallel, or in mixed connection is placed in the box. The battery pack may also include other structures. For example, the battery pack may also include a busbar component for realizing electrical connection between multiple battery cells.

[0080] The present application also provides an energy storage device, which includes a mounting container and a battery pack, wherein the battery pack is disposed in the mounting container.

[0081] This application also provides a battery cell, see Figures 1 to 8 The battery cell comprises a housing 1, an explosion-proof valve 2, a bare battery cell 3 and an elastic member 4. The explosion-proof valve 2 is arranged in the housing 1, and the bare battery cell 3 is arranged in the housing 1. The arrangement direction of the explosion-proof valve 2 and the bare battery cell 3 is a first direction 3a. The elastic member 4 is located along the first direction 3a between the bare battery cell 3 and the housing wall of the housing 1 on the side facing the explosion-proof valve 2 along the first direction 3a.

[0082] A battery cell is a basic unit that can realize the mutual conversion between chemical energy and electrical energy.

[0083] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0084] In the embodiment of the present application, the battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., but the embodiment of the present application is not limited to this.

[0085] Exemplarily, the present application does not limit the type of the bare battery cell 3 , and the bare battery cell 3 may be a square wound battery cell or a laminated battery cell.

[0086] The explosion-proof valve 2 refers to a component used to prevent the battery cell from exploding under abnormal circumstances. The valve of the explosion-proof valve 2 can remain closed under a certain pressure, and the valve opens when the internal gas pressure of the battery cell reaches a certain level to release the gas.

[0087] Exemplarily, the housing 1 includes a shell 11 and a top cover 10 , the top cover 10 is disposed on the shell 11 , the explosion-proof valve 2 is disposed on the top cover 10 , and the bare battery cell 3 is disposed inside the shell 11 .

[0088] Exemplarily, the first direction 3 a is arranged along the length direction of the bare battery cell 3 .

[0089] Exemplarily, the first direction 3 a is arranged perpendicular to the thickness direction of the bare cell 3 .

[0090] In the solution of the embodiment of the present application, an elastic member 4 is provided along the first direction 3a between the bare cell 3 and the shell wall of the shell 1 along the first direction 3a toward the explosion-proof valve 2. When thermal runaway occurs inside the battery cell, the bare cell 3 will be driven by the airflow and thus run toward the explosion-proof valve 2 along the first direction 3a. The elastic member 4 can play a certain buffering role on the bare cell 3, reduce the rigid impact on the bare cell 3, and thus alleviate the situation where the bare cell 3 is deformed due to external loads and causes a short circuit.

[0091] In one embodiment, please refer to Figure 2 The battery cell also includes an insulating member 5, which is located between the bare battery cell 3 and the shell wall of the shell 1 along the first direction 3a toward the explosion-proof valve 2, and the elastic member 4 is at least partially located on the side of the insulating member 5 facing the bare battery cell 3 along the first direction 3a.

[0092] The insulating member 5 is a component made of insulating material and located between the bare battery cell 3 and the shell wall where the pole is located, and is used to alleviate the short circuit between the bare battery cell 3 and the shell wall.

[0093] In the solution of the embodiment of the present application, the battery cell further includes an insulating member 5, which is located between the bare cell 3 and the shell wall of the shell 1 along the first direction 3a toward the explosion-proof valve 2. The insulating member 5 can alleviate the short circuit between the bare cell 3 and the shell 11, and the insulating member 5 can reduce the rigid collision between the bare cell 3 and the shell 11 to a certain extent, thereby further reducing the short circuit of the bare cell 3.

[0094] Exemplarily, the bare cell 3 is a laminated cell or a square wound cell.

[0095] Exemplarily, the bare cell 3 includes a positive electrode sheet, a negative electrode sheet and a separator, and the separator is located between the positive electrode sheet and the negative electrode sheet.

[0096] In one embodiment, please refer to Figure 2 The insulating member 5 is formed with a first protrusion 5 a, the first protrusion 5 a protrudes toward the bare battery cell 3 along the first direction 3 a, and the elastic member 4 is connected to a side of the first protrusion 5 a facing the bare battery cell 3 .

[0097] Exemplarily, the elastic member 4 is bonded to the first protrusion 5 a.

[0098] Exemplarily, when projected along the first direction 3 a , the projection area of ​​the elastic member 4 overlaps with the projection area of ​​the first protrusion 5 a .

[0099] Exemplarily, there are multiple first bumps 5a, and the multiple first bumps 5a are arranged at intervals.

[0100] Exemplarily, the first protrusion 5a is in the shape of a rectangular block.

[0101] In the solution of the embodiment of the present application, the insulating member 5 is formed with a first protrusion 5a, and the first protrusion 5a protrudes along the first direction 3a toward the bare cell 3. The first protrusion 5a can increase the size of the insulating member 5 along the first direction 3a, and the insulating member 5 can abut against the bare cell 3 through the first protrusion 5a, thereby pressing the bare cell 3 to reduce the movement of the bare cell 3 along the first direction 3a during the operation of the battery cell.

[0102] It is understandable that the embodiments of the present application are not limited to the insulating member 5 being formed with the first protrusion 5a. Exemplarily, the insulating member 5 is a plate-shaped structure.

[0103] In one embodiment, please refer to Figure 3 The first protrusion 5a forms an avoidance cavity 5b, the pole ear of the bare battery cell 3 is located in the avoidance cavity 5b, the first protrusion 5a is arranged circumferentially around the pole ear, the elastic member 4 is annular, and the elastic member 4 surrounds the pole ear.

[0104] In the solution of the embodiment of the present application, the first protrusion 5a is formed with an avoidance cavity 5b, the tab of the bare cell 3 is located in the avoidance cavity 5b, and the elastic member 4 is annular, and the elastic member 4 surrounds the tab. The first protrusion 5a is formed with an avoidance cavity 5b to avoid the tab of the bare cell 3 and reduce the situation where the tab is pressed by the insulating member 5. The elastic member 4 surrounding the tab can make full use of the space around the tab, and maximize the contact area between the elastic member 4 and the bare cell 3, thereby increasing the buffering effect of the elastic member 4 and further reducing the situation where the bare cell 3 short-circuits.

[0105] It is understandable that the embodiments of the present application are not limited to the elastic member 4 surrounding the pole ear. Exemplarily, the elastic member 4 is located on both sides of the pole ear along the width direction or thickness direction of the bare battery cell 3, and the width direction of the bare battery cell 3 is arranged perpendicular to the thickness direction of the bare battery cell 3 and the first direction 3a, respectively, and the thickness direction of the bare battery cell 3 is arranged perpendicular to the width direction of the bare battery cell 3 and the first direction 3a, respectively.

[0106] In one embodiment, please refer to Figure 4 There are two elastic members 4 , and the two elastic members 4 are respectively located on both sides of the insulating member 5 along the second direction 4 a , and the second direction 4 a is arranged to cross the first direction 3 a .

[0107] Exemplarily, the second direction 4 a is arranged along the width direction of the bare battery cell 3 .

[0108] Exemplarily, the second direction 4a is arranged perpendicular to the first direction 3a.

[0109] Exemplarily, the two paired tabs of the bare battery cell 3 are arranged along the width direction of the bare battery cell 3 .

[0110] In the embodiment of the present application, there are two elastic members 4, and the two elastic members 4 are respectively located on both sides of the insulating member 5. The spaced arrangement of the elastic members 4 can balance the blocking effect of the elastic members 4 on the bare battery cell 3, so that the bare battery cell 3 is subjected to a more uniform force.

[0111] It is understandable that the embodiment of the present application is not limited to the number of two elastic members 4, and the two elastic members 4 are respectively located on both sides of the insulating member 5 along the second direction 4a. Exemplarily, the number of elastic members 4 is single, and the elastic member 4 is located on one side of the insulating member 5 along the second direction 4a.

[0112] In one embodiment, please refer to Figure 5 A mounting groove 4b is formed on one side of the elastic member 4 facing the insulating member 5, the opening of the mounting groove 4b faces the insulating member 5, and the insulating member 5 is partially located in the mounting groove 4b.

[0113] Exemplarily, the mounting groove 4b is a square groove.

[0114] Exemplarily, the insulating member 5 is snapped into the mounting groove 4 b , and the insulating member 5 is connected to the elastic member 4 by interference fit.

[0115] In the embodiment of the present application, a mounting groove 4b is formed on one side of the elastic member 4 facing the insulating member 5, and the opening of the mounting groove 4b faces the insulating member 5. The insulating member 5 can be connected to the elastic member 4 through the mounting groove 4b, so that the insulating member 5 and the elastic member 4 are connected as one body, which can alleviate the shaking of the elastic member 4 inside the battery cell to a certain extent, and the elastic member 4 can more stably buffer the bare battery cell 3 during operation.

[0116] It is understandable that the embodiments of the present application are not limited to the insulating member 5 being partially located in the mounting groove 4b. Exemplarily, the elastic member 4 is separated from the insulating member 5, and the elastic member 4 can move relative to the insulating member 5 inside the battery cell.

[0117] In one embodiment, along the arrangement direction of the explosion-proof valve 2 and the bare battery cell 3, the size of the elastic member 4 is a target size, the range of the target size is 0.5 mm to 5.0 mm, the contact area between the elastic member 4 and the bare battery cell 3 is a first area, the projection area of ​​the bare battery cell 3 in the arrangement direction of the explosion-proof valve 2 and the bare battery cell 3 is a second area, the units of the first area and the second area are the same, the ratio of the first area to the second area is a first ratio, and the range of the first ratio is 5.1% to 44.7%.

[0118] Exemplarily, the target size is 0.5 mm, 1.0 mm, 2.0 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, or 5.0 mm.

[0119] It is understandable that the target size can be measured by a ruler or a vernier caliper at normal temperature and pressure before the battery cell is charged for the first time.

[0120] Exemplarily, the first ratio may be 5.1%, 10.0%, 15.0%, 20.0%, 30.0%, 35.0%, 40.0%, 44.0% or 44.7%.

[0121] mm refers to the unit of length, millimeter.

[0122] In the embodiment of the present application, the target size and the first ratio are within a suitable range, so that the size of the elastic member 4 can be as small as possible while providing a certain buffering effect, thereby increasing the size of the bare battery cell 3 along the length direction, and the energy density of the battery cell is higher.

[0123] Exemplarily, the target size is D, the first area is A, the second area is B, and D and the ratio A / B have the following relationship:

[0124]

[0125] For example, dimension D is Figure 8 as shown in .

[0126] It can be understood that the ratio between the first area and the second area is the first ratio. The thicker the thickness of the elastic member 4 is, the better the buffering effect of the elastic member 4 to prevent the bare battery cell 3 from moving upward after the explosion-proof valve 2 is opened, and the better the protection effect of the bare battery cell 3. The larger the first ratio is, the larger the effective area of ​​the elastic member 4 is, the better the stress concentration is relieved, and the better the buffering effect of the elastic member 4 is. Therefore, when the thickness of the elastic member 4 takes a maximum value, the first ratio has a minimum value, so that the elastic member 4 has a certain crimping area to relieve the short circuit of the bare battery cell 3, so the ratio of the thickness of the elastic member 4 to the first ratio has a maximum value. On the contrary, when the first ratio has a maximum value due to the internal space limitation of the battery cell, the thickness of the elastic member 4 has a minimum value, so that the elastic member 4 has a certain buffering ability to relieve the short circuit of the bare battery cell 3, that is, the ratio of the thickness of the elastic member 4 to the first ratio has a minimum value. The applicant obtained the following test data by adjusting the thickness of the elastic member 4 and the first ratio.

[0127] D(mm) A / B D / (A / B) Short circuit condition Test 1 0.5 44.7％ 1.1 normal Test 2 0.5 22.3％ 2.2 normal Test 3 0.5 5.1％ 9.8 normal Test 4 2 44.7％ 4.5 normal Test 5 2 22.3％ 9.0 normal Test 6 2 5.1％ 39.2 normal Test 7 5 44.7％ 11.2 normal Test 8 5 22.3％ 22.4 normal Test 9 5 5.1％ 98.0 normal Test 10 0.3 44.7％ 0.7 Short Circuit Test 11 0.2 44.7％ 0.4 Short Circuit Test 12 5 4.5％ 111.1 Short Circuit Test 13 5 3.2％ 156.3 Short Circuit

[0128] In one embodiment, along the arrangement direction of the explosion-proof valve 2 and the bare battery cell 3, the size of the elastic member 4 is a target size, the target size ranges from 0.5 mm to 5.0 mm, and the valve opening pressure of the explosion-proof valve 2 is a target pressure, the target pressure ranges from 0.5 MPa to 5.5 MPa.

[0129] Illustratively, the target pressure is 0.5 MPa, 1.0 MPa, 1.5 MPa, 2.0 MPa, 3.0 MPa, 4.0 MPa, 4.5 MPa, 5.0 MPa or 5.5 MPa.

[0130] MPa refers to the pressure unit megapascal.

[0131] It is understandable that the target pressure can be obtained by setting a pressure gauge to measure the closed container equipped with the explosion-proof valve 2, and continuously inflating the closed container until the explosion-proof valve 2 opens. The valve opening pressure of the explosion-proof valve 2 is the target pressure.

[0132] In the embodiment of the present application, the magnitude of the target pressure can control the load on the bare cell 3 when it rushes toward the explosion-proof valve 2 in the event of thermal runaway. The target pressure within a suitable range can enable the elastic member 4 to buffer the bare cell 3 more stably, and further, alleviate the situation where the explosion-proof valve 2 is opened by the gas generated by the bare cell 3 in normal operation.

[0133] For example, the target size is D, the valve opening pressure of the explosion-proof valve 2 is P, and the unit of P is MPa. There is the following relationship:

[0134] 0.25≤D×P≤8.50

[0135] It is understandable that the greater the thickness of the elastic member 4, the greater the buffering effect of the elastic member 4 on the bare battery cell 3. The higher the valve opening pressure of the explosion-proof valve 2, the stronger the impact load caused by the bare battery cell 3 rushing up at the moment of valve opening, and the more serious the damage to the bare battery cell 3. When the thickness of the elastic member 4 takes a maximum value due to the idle internal space of the bare battery cell 3, the valve opening pressure has a maximum value to alleviate the situation where the bare battery cell 3 short-circuits due to a large load, so the product of D and P has a maximum value. When the valve opening pressure has a minimum value due to the demand for gas production of the bare battery cell 3 under normal working conditions, the thickness of the elastic member 4 has a minimum value, so that the elastic member 4 can provide a certain buffering effect, so the product of D and P has a minimum value. The applicant obtained the following test data by adjusting the thickness of the elastic member 4 and the first ratio.

[0136]

[0137]

[0138] In one embodiment, the elastic modulus of the elastic member is greater than or equal to 0.1 MPa and less than or equal to 1000 MPa.

[0139] Exemplarily, the elastic modulus of the elastic member 4 is 0.1 MPa, 0.5 MPa, 1.0 MPa, 10 MPa, 50 MPa, 100 MPa, 200 MPa, 300 MPa, 800 MPa, 900 MPa or 1000 MPa.

[0140] In the embodiment of the present application, the elastic modulus of the elastic member 4 is within an appropriate range so that the deformation of the elastic member 4 is as small as possible when buffering the bare battery cell 3, thereby reducing the size of the elastic member 4 along the first direction 3a and reducing the size of the battery cell along the first direction 3a.

[0141] In one embodiment, the elastic modulus of the elastic member is greater than or equal to 0.5 MPa and less than or equal to 100 MPa.

[0142] In the embodiment of the present application, the elastic modulus of the elastic member 4 can further increase the buffering effect of the elastic member 4 on the bare battery cell 3 within a smaller range, and can control the deformation of the elastic member 4 within an appropriate range.

[0143] In one embodiment, please refer to Figures 6 to 8 The housing 1 includes a top cover 10 and a shell 11 connected to each other, the top cover 10 is covered on the shell 11, the explosion-proof valve 2 is arranged on the top cover 10, one of the elastic member 4 and the top cover 10 is formed with a second protrusion 4c, and the other is formed with a positioning groove 10a, and the second protrusion 4c is at least partially located in the positioning groove 10a to install the elastic member 4.

[0144] Exemplarily, the second protrusion 4 c is formed on the elastic member 4 , and the positioning groove 10 a is formed on the top cover 10 .

[0145] Exemplarily, there are multiple second bumps 4c, and the multiple second bumps 4c are arranged at intervals along the second direction 4a.

[0146] In the embodiment of the present application, a second protrusion 4c and a positioning groove 10a that can cooperate with each other are formed between the top cover 10 and the elastic member 4. The cooperation between the second protrusion 4c and the positioning groove 10a can quickly install the elastic member 4, and can play a certain role in limiting the elastic member 4, thereby alleviating the shaking of the elastic member 4 inside the battery cell.

[0147] It is understandable that the embodiment of the present application is not limited to the elastic member 4 being installed on the top cover 10 via the second protrusion 4c and the positioning groove 10a.

[0148] In one embodiment, the elastic member 4 is made of insulating material.

[0149] Exemplarily, the elastic member 4 is made of rubber material, silicone material, or elastic polyurethane material.

[0150] In the embodiment of the present application, the elastic member 4 is made of insulating material, which can reduce the short circuit of the battery cell during use. The elastic member 4 can replace the insulating member 5 to alleviate the short circuit between the bare cell 3 and the housing 11, thereby reducing the number of components inside the battery cell.

[0151] In one embodiment, the elastic member 4 includes an elastic member body and a protective layer that are interconnected. The protective layer is coated on the elastic member body. The protective layer includes an insulating layer and / or an anti-corrosion layer. The anti-corrosion layer is used to prevent the elastic member 4 body from being corroded by the electrolyte.

[0152] Exemplarily, the material of the anti-corrosion layer is soft polyvinyl chloride, polytetrafluoroethylene or polyurethane.

[0153] In the embodiment of the present application, the elastic member 4 is a multi-layer structure, and the protective layer can, to a certain extent, alleviate the situation where the bare battery cell 3 directly contacts the external metal, thereby causing a short circuit, or the situation where the elastic member 4 is corroded by the electrolyte.

[0154] In one embodiment, please refer to Figures 1 to 4The battery cell includes a shell 1, an explosion-proof valve 2, a bare cell 3 and an elastic member 4. The explosion-proof valve 2 is arranged in the shell 1, and the bare cell 3 is arranged in the shell 1. The explosion-proof valve 2 and the bare cell 3 are arranged in the first direction 3a. The elastic member 4 is located between the bare cell 3 and the shell wall of the shell 1 along the first direction 3a facing the explosion-proof valve 2. The battery cell also includes an insulating member 5, which is located between the bare cell 3 and the shell wall of the shell 1 along the first direction 3a facing the explosion-proof valve 2. The elastic member 4 is at least partially located on the side of the insulating member 5 facing the bare cell 3 along the first direction 3a. The insulating member 5 is formed with a first protrusion 5a, which protrudes toward the bare cell 3 along the first direction 3a, and the elastic member 4 is connected to the side of the first protrusion 5a facing the bare cell 3. The number of elastic members 4 is two, and the two elastic members 4 are respectively located on both sides of the insulating member 5 along the second direction 4a, and the second direction 4a is arranged crosswise with the first direction 3a. The elastic member 4 is formed with a mounting groove 4b on one side facing the insulating member 5, the opening of the mounting groove 4b faces the insulating member 5, and the insulating member 5 is partially located in the mounting groove 4b. The elastic modulus of the elastic member 4 is greater than or equal to 0.5 MPa and less than or equal to 100 MPa. The elastic member 4 includes an elastic member body and a protective layer connected to each other, the protective layer is coated on the elastic member 4 body, and the protective layer includes an insulating layer and / or an anti-corrosion layer, and the anti-corrosion layer is used to prevent the elastic member 4 body from being corroded by the electrolyte.

[0155] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: shell; An explosion-proof valve, arranged on the housing; A bare battery cell is disposed in the housing, and the explosion-proof valve and the bare battery cell are arranged in a first direction; An elastic member, wherein the elastic member is located along the first direction between the bare battery core and a shell wall of the shell along the first direction toward the explosion-proof valve.

2. The battery cell according to claim 1, characterized in that: The battery cell further includes an insulating member located between the bare cell and a shell wall of the shell along the first direction toward the explosion-proof valve, and the elastic member is at least partially located along the first direction on a side of the insulating member facing the bare cell.

3. The battery cell according to claim 2, characterized in that: The insulating member is formed with a first protrusion, the first protrusion protrudes toward the bare battery cell along the first direction, and the elastic member is connected to a side of the first protrusion facing the bare battery cell.

4. The battery cell according to claim 3, characterized in that: The first protrusion forms an avoidance cavity, the pole ear of the bare battery cell is located in the avoidance cavity, the first protrusion is arranged circumferentially around the pole ear, and the elastic member is annular and surrounds the pole ear.

5. The battery cell according to claim 2, characterized in that: The number of the elastic members is two, and the two elastic members are respectively located on both sides of the insulating member along the second direction, and the second direction is arranged to cross the first direction.

6. The battery cell according to claim 5, characterized in that: A mounting groove is formed on a side of the elastic member facing the insulating member, an opening of the mounting groove faces the insulating member, and the insulating member is partially located in the mounting groove.

7. The battery cell according to any one of claims 1 to 6, characterized in that: Along the arrangement direction of the explosion-proof valve and the bare battery cell, the size of the elastic part is a target size, the range of the target size is 0.5mm to 5.0mm, the contact area between the elastic part and the bare battery cell is a first area, the area of ​​the projection area of ​​the bare battery cell in the arrangement direction of the explosion-proof valve and the bare battery cell is a second area, the units of the first area and the second area are the same, the ratio of the first area to the second area is a first ratio, and the range of the first ratio is 5.1% to 44.7%.

8. The battery cell according to any one of claims 1 to 6, characterized in that: Along the arrangement direction of the explosion-proof valve and the bare battery cell, the size of the elastic member is a target size, the range of the target size is 0.5mm to 5.0mm, and the valve opening pressure of the explosion-proof valve is a target pressure, the range of the target pressure is 0.5MPa to 5.5MPa.

9. The battery cell according to any one of claims 1 to 6, characterized in that: The elastic modulus of the elastic member is greater than or equal to 0.1 MPa and less than or equal to 1000 MPa.

10. The battery cell according to claim 9, characterized in that: The elastic modulus of the elastic member is greater than or equal to 0.5 MPa and less than or equal to 100 MPa.

11. The battery cell according to any one of claims 1 to 6, characterized in that: The shell includes a top cover and a shell body connected to each other, the top cover is arranged on the shell body, the explosion-proof valve is arranged on the top cover, one of the elastic member and the top cover is formed with a second protrusion, and the other is formed with a positioning groove, and the second protrusion is at least partially located in the positioning groove to install the elastic member.

12. The battery cell according to any one of claims 1 to 6, characterized in that: The elastic member is made of insulating material.

13. The battery cell according to any one of claims 1 to 6, characterized in that: The elastic member comprises an elastic member body and a protective layer which are connected to each other. The protective layer is coated on the elastic member body. The protective layer comprises an insulating layer and / or an anti-corrosion layer. The anti-corrosion layer is used to prevent the elastic member body from being corroded by the electrolyte.

14. A battery pack, characterized in that: include: Box; At least one battery cell according to any one of claims 1 to 13 is disposed inside the box.

15. An electrical device, characterized in that: include: Device body; The battery pack according to claim 14 is used to supply power to a device body.

16. An energy storage device, characterized in that: include: Install the container; The battery pack according to claim 14 is disposed in the mounting container.

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