Battery monomer, battery device and energy storage device

Abstract

The utility model relates to the field of batteries, and discloses a single battery, a battery device and an energy storage device. The packaging body wraps the outer side of the electrode assembly and is provided with a packaging part extending along the periphery of the electrode assembly, the packaging part comprises a first packaging area and a second packaging area in the extending direction of the packaging part, the first packaging area comprises an edge sealing section and an avoiding section which are arranged in the width direction of the packaging part, the thickness of the avoiding section is larger than that of the edge sealing section, and the thickness of the second packaging area is larger than that of the edge sealing section. The width of the edge sealing section is smaller than the packaging width of the second packaging area. According to the technical scheme provided by the embodiment of the invention, effective packaging isolation can be realized, and the internal environment of the battery monomer is maintained; and the width of the sealing edge at the first packaging area is smaller than that of other areas, so that the bearable pressure is smaller than that of other areas, high-pressure gas and heat can be quickly discharged from the first packaging area during thermal runaway, the thermal runaway fixed exhaust position is realized, the pressure is guided to be directionally discharged, and the reliability of the single battery is improved.

Description

Technical Field

[0001] This application relates to the field of batteries, and specifically to a battery cell, a battery device, and an energy storage device. Background Art

[0002] New energy batteries are increasingly widely used in life and industries. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also increasingly used in the energy storage field, etc. In new energy vehicles equipped with batteries, the batteries can be used to provide power wholly or partly. In the energy storage field, the batteries can be installed in an energy storage box or directly installed on the user side.

[0003] A soft-pack battery is a battery that uses a flexible packaging material (such as an aluminum-plastic film) as the package body, and its positive and negative electrode materials and electrolyte are encapsulated together in a soft film form. Soft-pack batteries are usually hermetically sealed, and the exhaust direction during thermal runaway is uncontrollable. The gas sprays out in no fixed direction and at no fixed position, causing potential safety hazards. Summary of the Utility Model

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an energy storage device, which can alleviate the problem of uncontrollable exhaust during battery thermal runaway.

[0005] In a first aspect, this application provides a battery cell, including: an electrode assembly; a package body, the package body covering the outside of the electrode assembly and having a sealing portion extending along the outer periphery of the electrode assembly. In the extending direction of the sealing portion, the sealing portion includes a first sealing area and a second sealing area. The first sealing area includes a sealing edge section and an avoidance section arranged along the width direction of the sealing portion. A part of the first sealing area is sealed to form the sealing edge section, and another part of the first sealing area is not sealed to form the avoidance section. The thickness of the avoidance section is greater than that of the sealing edge section. In the width direction of the sealing portion, the width of the sealing edge section is smaller than the width of the second sealing area.

[0006] In the technical solution of the embodiment of this application, by designing a sealing edge section and a second sealing area with different sealing widths on the package body, effective encapsulation isolation can be achieved to maintain the internal environment of the battery cell. Also, since the sealing width at the first sealing area is smaller than that of other areas, the pressure it can withstand is also smaller than that of other areas. During thermal runaway, the sealing edge at the first sealing area will be broken first, and high-pressure gas and heat can be quickly discharged from the first sealing area, realizing a fixed exhaust position during thermal runaway, guiding the pressure to be discharged in a specific direction, and improving the reliability of the battery cell.

[0007] In some embodiments, in the width direction of the encapsulation part, the width of the first encapsulation area is W0, and the maximum width of the avoidance section is W1, where 0.1 ≤ W1 / W0 ≤ 0.7. In the above technical solution, the service life of the battery cell can be guaranteed to a certain extent, and at the same time, a fixed exhaust position for thermal runaway can be achieved, guiding the pressure to be discharged directionally, thereby improving the reliability of the battery cell.

[0008] In some embodiments, in the width direction of the encapsulation part, the avoidance section is located in the middle of the first encapsulation area. In the above technical solution, it is possible to avoid generating debris at the avoidance section during subsequent cutting, thus avoiding problems such as blockage of the exhaust position caused by cutting debris, and at the same time, it is possible to avoid electrolyte hiding in the avoidance section, which affects the cycle life of the battery cell.

[0009] In some embodiments, the avoidance section is closer to or farther from the electrode assembly relative to the edge-sealing section. In the above technical solution, when the avoidance section is located on the side of the edge-sealing section away from the electrode assembly, the avoidance section is spaced apart from the electrode assembly and the electrolyte, thus avoiding electrolyte hiding in the avoidance section and affecting the cycle life of the battery cell; when the avoidance section is located on the side of the edge-sealing section close to the electrode assembly, during subsequent cutting, it is not easy to cut the avoidance section, avoiding the generation of cutting debris, and further avoiding problems such as blockage of the exhaust position caused by cutting debris.

[0010] In some embodiments, the thickness of the avoidance section is H1, and the thickness of the edge-sealing section is H2, where 0.05 ≤ H2 / H1 ≤ 0.4. In the above technical solution, it is possible to avoid warping or deformation in the first encapsulation area, which affects the appearance and sealing strength, and improve the service life of the battery cell.

[0011] In some embodiments, the maximum thickness of the edge-sealing section is the same as the maximum thickness of the second encapsulation area. In the above technical solution, the encapsulation part can be encapsulated using a relatively flat heat sealer, which is convenient for encapsulation, and at the same time, it can avoid too large or too small a thickness difference between the second encapsulation area and the avoidance section, which affects the appearance and sealing strength of the battery cell.

[0012] In some embodiments, the packaging body includes two encapsulation half-films. Each encapsulation half-film includes an outer layer, a middle layer, and an inner layer arranged in sequence. The inner layers of the two encapsulation half-films of the avoidance section are arranged at intervals, and the inner layers of the two encapsulation half-films of the edge-sealing section are connected to each other. In the above technical solution, the pressure that the first encapsulation area can withstand is reduced. During thermal runaway, the edge-sealing at the first encapsulation area will be broken first, and high-pressure gas and heat can be quickly discharged from the first encapsulation area, achieving a fixed exhaust position for thermal runaway, guiding the pressure to be discharged directionally, improving the reliability of the battery cell, and enhancing the safety of the system.

[0013] In some embodiments, in the extending direction of the encapsulation part, the length of the first encapsulation area is less than that of the second encapsulation area. In the above technical solution, the reliability of the edge sealing of the encapsulation part is improved, the probability of leakage of the battery cell during normal use is reduced, and the service life of the battery cell is prolonged.

[0014] In some embodiments, the electrode assembly includes a main body part and two pole ear parts. The two pole ear parts are located on one side of the main body part, and the first encapsulation area is located on the other side of the main body part. In the above technical solution, during thermal runaway, the first encapsulation area can guide the gas to discharge from the side opposite to the pole ear part, avoiding the impact of high-temperature and high-pressure gas on the pole ear part and reducing the risk of high-voltage short circuit.

[0015] In some embodiments, the electrode assembly includes a main body part and two pole ear parts. The two pole ear parts are located on at least one side of the main body part, and the first encapsulation area is located on the side of the main body part where the pole ear part is provided. In the above technical solution, during thermal runaway, the edge seal at the first encapsulation area will be broken first, and the high-pressure gas and heat can be quickly discharged from the first encapsulation area, realizing a fixed exhaust position for thermal runaway, guiding the pressure to be discharged directionally, and improving the reliability of the battery cell.

[0016] In a second aspect, the present application provides a battery device, which includes the battery cell in the above embodiments.

[0017] In a third aspect, the present application provides an energy storage device, which includes the battery device in the above embodiments.

[0018] The above description is only an overview of the technical solution of the present application. In order to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are given below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. And in all the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0020] Figure 1 is a schematic structural diagram of an energy storage device provided by some embodiments of the present application;

[0021] Figure 2 is a schematic diagram of a battery device provided by some embodiments of the present application;

[0022] Figure 3Schematic diagram of a battery cell provided by some embodiments of the present application;

[0023] Figure 4 is Figure 3 the enlarged view of the circled area A in

[0024] Figure 5 is along Figure 4 the cross-sectional view of the package along the B-B line in

[0025] Figure 6 Schematic diagram of a battery cell provided by some other embodiments of the present application;

[0026] Figure 7 is Figure 6 the enlarged view of the circled area C in

[0027] Figure 8 Schematic diagram of a battery cell provided by some other embodiments of the present application;

[0028] Figure 9 is Figure 8 the enlarged view of the circled area D in

[0029] Figure 10 Schematic diagram of a battery cell provided by some other embodiments of the present application;

[0030] Figure 11 Schematic diagram of the thermal head of the encapsulation machine provided by some embodiments of the present application.

[0031] Reference numerals:

[0032] Battery device 1000, energy storage device 3000,

[0033] Battery cell 100, control unit 400, box body 500,

[0034] Electrode assembly 10, main body part 11, tab part 12, package 20, encapsulation part 21, first encapsulation area 22, sealing edge section 221, avoidance section 222, second encapsulation area 23, encapsulation semi-film 24, outer layer 241, intermediate layer 242, inner layer 243,

[0035] Thermal head 30, avoidance groove 31. Detailed implementation manners

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, rather than all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0037] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application pertains; the terms used in this application in the specification are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order or primary-secondary relationship.

[0038] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0039] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "joined", and "attached" shall 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 direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] The term "and / or" in this application is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally represents an "or" relationship between the associated objects before and after.

[0041] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components in the embodiments of this application shown in the drawings, as well as the overall thickness, length, width, etc. of the integrated device, are only illustrative and should not constitute any limitation to this application.

[0042] The term "plurality" as used in this application refers to two or more (including two).

[0043] In this application, a battery refers to a single physical module that includes one or more battery cells to provide a higher voltage and capacity. For example, the batteries mentioned in this application may include battery modules or battery packs, etc. Some batteries may include a casing for encapsulating one or more battery cells or multiple battery modules. The casing can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells. Of course, there are also some batteries that do not include the above-mentioned casing and are directly installed in the battery installation compartment of the electrical device.

[0044] In this application, the battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited thereto. The battery cells can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc., and the embodiments of this application are also not limited thereto.

[0045] For example, a battery cell may include a package body, an electrode assembly, and an electrolyte. The package body is used to accommodate the electrode assembly and the electrolyte. The electrode assembly is composed of a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode tab and the negative electrode tab. The positive electrode tab includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the coated positive electrode active material layer protrudes from the positive electrode current collector with the coated positive electrode active material layer. The positive electrode current collector without the coated positive electrode active material layer serves as the positive electrode ear. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc.

[0046] The negative electrode tab includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the coated negative electrode active material layer protrudes from the negative electrode current collector with the coated negative electrode active material layer. The negative electrode current collector without the coated negative electrode active material layer serves as the negative electrode ear. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. To ensure that a large current can pass through without fusing, the number of positive electrode ears is multiple and stacked together, and the number of negative electrode ears is multiple and stacked together.

[0047] The material of the separator can be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly can be a wound structure or a stacked structure, and the embodiments of this application are not limited thereto.

[0048] A soft-pack battery is a battery that uses flexible packaging materials (such as aluminum-plastic film) as its packaging body. Its positive and negative electrode materials and electrolyte are encapsulated together in the form of a soft film. Soft-pack batteries are conventionally sealed. During the use of soft-pack batteries, short circuits, overcharging and other abnormal conditions may occur. The temperature inside the battery will rise rapidly, releasing a large amount of heat and gas, and the aluminum-plastic film will swell. When the pressure reaches a certain value, the edge of the aluminum-plastic film will rupture and exhaust will be discharged. However, due to the lack of a pressure relief structure, the exhaust direction is uncontrollable, and the gas is ejected in no fixed direction or fixed position, posing a safety hazard to the entire battery structure and even to people.

[0049] To this end, the present application proposes a battery cell, comprising: an electrode assembly; a packaging body, the packaging body being coated on the outside of the electrode assembly and having a packaging portion extending along the periphery of the electrode assembly, in the extension direction of the packaging portion, the packaging portion comprising a first packaging area and a second packaging area, the first packaging area comprising an edge sealing section and an avoidance section arranged along the width direction of the packaging portion, a portion of the first packaging area being packaged to form an edge sealing section, and another portion of the first packaging area being unpackaged to form an avoidance section, the thickness of the avoidance section being greater than the thickness of the edge sealing section, and in the width direction of the packaging portion, the width of the edge sealing section being less than the width of the packaging of the second packaging area.

[0050] In the battery cell of the above-mentioned structure, by designing edge sealing sections and second packaging areas with different packaging widths on the packaging body, effective packaging isolation can be achieved and the internal environment of the battery cell can be maintained; and because the edge sealing width at the first packaging area is smaller than that of other areas, the pressure it can withstand is also smaller than that of other areas. In the event of thermal runaway, the edge sealing at the first packaging area will be broken first, and high-pressure gas and heat can be quickly discharged from the first packaging area, realizing a fixed exhaust position for thermal runaway, guiding the pressure to be discharged in a directional manner, and improving the reliability of the battery cell.

[0051] The battery device provided in the embodiments of the present application includes the above-mentioned battery cell. The battery device can be used, but is not limited to, in power storage systems, vehicles, ships, aircraft, and other electrical devices.

[0052] An embodiment of the present application provides an energy storage device of the above-mentioned battery for storing electrical energy and capable of providing electrical energy. The energy storage device may include but is not limited to an energy storage container, an energy storage cabinet, etc.

[0053] In the following embodiments, for the convenience of description, the energy storage device 3000 of some embodiments of the present application is taken as an example for description, which will be described below with reference to the accompanying drawings.

[0054] Figure 1 This is a schematic diagram of the structure of the energy storage device 3000 provided in some embodiments of the present application. The energy storage device 3000 can be an energy storage container or an energy storage cabinet. Figure 1As shown, the energy storage device 3000 may include a battery device 1000 and a control unit 400. The control unit 400 is used to control the charge and discharge of the battery device 1000 to ensure the normal operation of the battery device 1000. For example, it is used to monitor parameters such as ambient temperature and humidity.

[0055] Figure 2 A schematic diagram of a battery provided for some embodiments of the present application. As Figure 2 shown, the battery device 1000 includes a box body 500. The box body can be divided into an upper box body (not shown) and a lower box body. The upper box body and the lower box body are mutually opposed to form a receiving space for the battery cells 100 therebetween.

[0056] Next, some embodiments of the present application will be described in detail with reference to Figures 3 to 11 the following. Figures 3 - 10 A three-dimensional schematic diagram of the battery cell 100 provided for some embodiments of the present application; Figure 11 A schematic diagram of the hot head of the encapsulator provided for some embodiments of the present application.

[0057] Some battery cells 100 of the embodiments of the present application include: an electrode assembly 10 and a packaging body 20. The packaging body 20 is coated on the outside of the electrode assembly 10. The packaging body 20 has a packaging portion 21 extending along the outer periphery of the electrode assembly 10. In the extending direction of the packaging portion 21, the packaging portion 21 includes a first packaging area 22 and a second packaging area 23. The first packaging area 22 includes a sealing edge section 221 and an avoidance section 222 arranged along the width direction of the packaging portion 21. A part of the first packaging area 22 is encapsulated to form the sealing edge section 221, and another part of the first packaging area 22 is not encapsulated to form the avoidance section 222. The thickness of the avoidance section 222 is greater than the thickness of the sealing edge section 221. In the width direction of the packaging portion 21, the width of the sealing edge section 221 is smaller than the width encapsulated by the second packaging area 23.

[0058] The battery cell 100 refers to a battery cell using a soft packaging film as the packaging body 20. The battery cell 100 has the characteristics of light structural weight and easy diversification of the outer contour shape compared with the battery cell with a rigid metal structure packaging body.

[0059] The electrode assembly 10 includes a main body portion 11 and a tab portion 12. The tab portion 12 is provided on one side or both sides of the main body portion 11. The tab portion 12 is used to lead out the current generated by the electrode assembly 10. The main body portion 11 is completely encapsulated inside the packaging body 20. A part of the tab portion 12 extends out from inside the packaging body 20. For example, a part of the tab portion 12 passes through the sealing edge formed by the encapsulation of the packaging portion 21 and extends out of the packaging portion 21 and is electrically connected to other devices (such as the tabs of other soft-pack battery cells).

[0060] The electrode assembly 10 includes electrode plates and a separator. There are two electrode plates, namely a positive electrode plate and a negative electrode plate. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator is arranged between the positive electrode plate and the negative electrode plate, which can prevent the short circuit between the positive and negative electrodes and at the same time allow the active ions to pass through. The laminated winding body formed by laminating and winding the positive electrode plate, the negative electrode plate and the separator. The electrode assembly 10 is not limited to the winding type. For example, it can also be a stacked type or other structural forms.

[0061] The packaging body 20, that is, the outer shell formed by bending and encapsulating the soft packaging film of the battery cell. The specific form of the packaging film forming the packaging body 20 is not limited. For example, it can be an aluminum-plastic film.

[0062] An accommodation cavity is provided inside the packaging body 20. The accommodation cavity is used to accommodate the electrode assembly 10 and the electrolyte. The charge and discharge functions of the battery cell are realized through the electrochemical reaction between the electrode assembly 10 and the electrolyte.

[0063] The encapsulation part 21 is the part of the packaging body 20 for encapsulation. The encapsulation part 21 is located outside the main body part 11. Before encapsulation, the packaging body 20 is an encapsulation film sheet. The encapsulation film sheet is bent to form two parts on both sides of the electrode assembly 10, that is, two encapsulation half films 24. The edges of the two encapsulation half films 24 form the encapsulation part 21. The edges of the two encapsulation half films 24 can be encapsulated by an encapsulation machine to form a sealing edge. The sealing edge can prevent the electrolyte inside the battery cell 100 from flowing out. At the same time, the sealing edge can effectively isolate the moisture and oxygen in the air and prevent them from entering the inside of the battery cell 100 to maintain the environment inside the battery cell 100.

[0064] The encapsulation part 21 extends along the outer periphery of the electrode assembly 10. For example, a part of the encapsulation part 21 is located on one side of the electrode assembly 10 in the first direction F1, and the encapsulation part 21 extends along the second direction F2. The width of the encapsulation part 21 in the first direction F1 is the same. For another example, a part of the encapsulation part 21 is located on one side of the electrode assembly 10 in the second direction F2, and the encapsulation part 21 extends along the first direction F1. The width of the encapsulation part 21 in the second direction F2 is the same. The encapsulation part 21 will not interfere with the electrode assembly 10. As Figures 3 - 5 shown, the encapsulation part 21 includes a first encapsulation area 22 and a second encapsulation area 23. The first encapsulation area 22 and the second encapsulation area 23 are arranged along the extension direction of the encapsulation part 21. Among them, the first encapsulation area 22 can be one or multiple. As Figure 3 shown, the first encapsulation area 22 and the second encapsulation area 23 are arranged along the first direction F1. As Figure 5As shown, the width direction of the encapsulation part 21 is the second direction F2. The first encapsulation area 22 includes a sealing edge section 221 and an avoidance section 222, and the sealing edge section 221 and the avoidance section 222 are arranged along the width direction of the encapsulation part 21.

[0065] As Figure 4 and Figure 5 shown, at the first encapsulation area 22, a part of the packaging body 20 is edge-sealed through the encapsulation process to form the sealing edge section 221, and the part that is not edge-sealed through the encapsulation process forms the avoidance section 222. The projected shape of the avoidance section 222 along the third direction F3 corresponds to the notch shape of the avoidance groove 31. The projected shape of the avoidance section 222 can be square, trapezoidal, semi-elliptical, semi-circular, V-shaped, I-shaped, etc.

[0066] The thickness of the avoidance section 222 is greater than the thickness of the sealing edge section 221. The thickness direction is perpendicular to the width direction of the encapsulation part 21 and perpendicular to the extending direction of the encapsulation part 21. The thickness direction here is the third direction F3 as Figure 6 shown, so that the position of the avoidance section 222 can be clearly observed on the battery cell 100.

[0067] That is to say, in the second direction F2, at the first encapsulation area 22, the width of the edge-sealed part formed by encapsulation is relatively small. That is, when encapsulating the encapsulation part 21, local voiding is carried out, so that the two encapsulation half-films 24 are not locally hot-pressed and encapsulated. While in the second encapsulation area 23, the two encapsulation half-films 24 can be encapsulated to form a wider edge-sealed part. Thus, the encapsulation width in the first encapsulation area 22 is less than that in other areas, and the pressure that can be borne is also less than that in other areas. When thermal runaway occurs inside the battery cell 100 and pressure relief is required, the edge-sealed part at the first encapsulation area 22 will be broken first, and the high-pressure gas and heat can be quickly discharged from the first encapsulation area 22, realizing a fixed exhaust position for thermal runaway, guiding the pressure to be discharged directionally, improving the reliability of the battery cell 100, and improving the safety of the system.

[0068] For the battery cell 100 according to the embodiment of the present application, by designing the sealing edge section 221 and the second encapsulation area 23 with different encapsulation widths on the packaging body 20, effective encapsulation isolation can be achieved to maintain the internal environment of the battery cell 100; and because the width of the edge-sealed part at the first encapsulation area 22 is less than that in other areas, and the pressure that can be borne is also less than that in other areas, the edge-sealed part at the first encapsulation area 22 will be broken first during thermal runaway, and the high-pressure gas and heat can be quickly discharged from the first encapsulation area 22, realizing a fixed exhaust position for thermal runaway, guiding the pressure to be discharged directionally, and improving the reliability of the battery cell 100.

[0069] Among them, the encapsulation part 21 can be heat-sealed by the hot head 30. The hot head 30 can heat the two encapsulation half-films 24 at the encapsulation part 21 to the molten state and then bond the two encapsulation half-films 24 together by pressing, so that the encapsulation part 21 forms a sealed edge structure. The hot head 30 can be provided with an avoidance groove 31, and no edge is formed at the position on the encapsulation part 21 corresponding to the avoidance groove 31.

[0070] That is to say, the present application can directly perform local encapsulation in the first encapsulation area 22 through the special-shaped hot head 30, so as to form a design with local non-encapsulation in the first heat-sealing area 22, so that this part can achieve the functions of fixing the exhaust position and guiding the pressure to be discharged in a specific direction. This encapsulation structure only requires heat-sealing and can be formed without adding additional processes after the heat-sealing process, improving the production and manufacturing efficiency and reducing the manufacturing cost.

[0071] Combined with Figure 11 As shown, the package 20 is encapsulated by the hot head 30 of the encapsulator. The end of the hot head 30 is provided with an avoidance groove 31. The hot head 30 can approach the encapsulation part 21 along the third direction F3. When the hot head 30 presses the encapsulation part 21 of the package 20, an edge section 221 can be formed at the first encapsulation area 22, and an avoidance section 222 is formed at the position corresponding to the avoidance groove 31. Combined with Figure 5 As shown, the two encapsulation half-films 24 are arranged at intervals at the avoidance section 222 and are heat-pressed at the edge section 221. Therefore, the thickness of the avoidance section 222 is greater than the thickness of the edge section 221.

[0072] As Figures 3 - 9 shown, in some embodiments, in the width direction of the encapsulation part 21, the width of the first encapsulation area 22 is W0, and the maximum width of the avoidance section 222 is W1, where 0.1 ≤ W1 / W0 ≤ 0.7.

[0073] As Figure 3 and Figure 4 shown, the encapsulation part 21 provided with the first encapsulation area extends along the first direction F1, and the width direction of the encapsulation part 21 is the second direction F2. In the second direction F2, the width of the first encapsulation area 22 is W0, and the maximum width of the avoidance section 222 is W1. If the width of the avoidance section 222 is too large, the width of the edge section 221 will be too small, and the reliability of the edge sealing is poor, and it is easy to have leakage or water vapor enter the inside of the battery cell 100 during the normal use of the battery cell 100, affecting the service life of the battery cell 100; if the width of the avoidance section 222 is too small, the purpose of effectively fixing the exhaust direction and the exhaust position cannot be achieved.

[0074] Thereby, W1 / W0 is limited between 0.1 and 0.7. W1 / W0 can be any value among 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or a range value between any two of them. Thereby, to a certain extent, the service life of the battery cell 100 can be ensured, and the fixed exhaust position of thermal runaway can be realized, guiding the pressure to be discharged directionally, and improving the reliability of the battery cell.

[0075] As Figure 4 shown, in some embodiments, in the width direction of the encapsulation part 21, the avoidance section 222 is located in the middle of the first encapsulation area 22.

[0076] As Figure 4 shown, the first encapsulation area 22 includes two edge-sealing sections 221, and the avoidance section 222 is located between the two edge-sealing sections 221. Thereby, the avoidance section 222 is located in the middle of the first encapsulation area 22. Through the above design, it is possible to avoid generating debris at the avoidance section 222 during subsequent cutting, avoiding problems such as the blockage of the exhaust position caused by the cutting debris, and also avoiding the electrolyte hiding in the avoidance section 222 and affecting the cycle life of the battery cell 100.

[0077] As Figures 6 - 9 shown, in some embodiments, the avoidance section 222 is closer to or farther from the electrode assembly 10 relative to the edge-sealing section 221.

[0078] As Figure 6 and Figure 7 shown, in some embodiments, the avoidance section 222 is located on the side of the edge-sealing section 221 far from the electrode assembly 10. Thereby, the avoidance section 222 is spaced apart from the electrode assembly 10 and the electrolyte, and it is possible to avoid the electrolyte hiding in the avoidance section 222 and affecting the cycle life of the battery cell 100.

[0079] As Figure 8 and Figure 9 shown, in some embodiments, the avoidance section 222 is located on the side of the edge-sealing section 221 close to the electrode assembly 10. Thereby, during subsequent cutting, it is not easy to cut the avoidance section 222, avoiding the generation of cutting debris, and further avoiding problems such as the blockage of the exhaust position caused by the cutting debris.

[0080] As Figure 5 shown, in some embodiments, the maximum thickness of the avoidance section 222 is H1, the maximum thickness of the edge-sealing section 221 is H2, and 0.05 ≤ H2 / H1 ≤ 0.4.

[0081] As Figure 5As shown, if H2 / H1 is too small, the thickness of the edge-sealing section 221 is too large, and the thickness of the avoidance section 222 is too small, resulting in insufficient heat-sealing strength and poor reliability of the edge-sealing. It is easy to have leakage or water vapor enter the interior of the battery cell 100 during normal use of the battery cell 100, affecting the service life of the battery cell 100; if H2 / H1 is too small, the thickness of the edge-sealing section 221 is too small, and the thickness of the avoidance section 222 is too large, warping or deformation is likely to occur at the first encapsulation area 22.

[0082] Therefore, H2 / H1 is limited to be between 0.05 and 0.4. H2 / H1 can be any value among 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4 or the range value between any two of them. Thus, warping or deformation of the first encapsulation area 22 can be avoided, which affects the appearance and sealing strength, and improves the service life of the battery cell 100.

[0083] In some embodiments, the maximum thickness of the edge-sealing section 221 is the same as the maximum thickness of the second encapsulation area 23. Thus, the encapsulation part 21 can be encapsulated by a relatively flat heat-sealing head 30, which is convenient for encapsulation. At the same time, the thickness difference between the second encapsulation area 23 and the avoidance section 222 is prevented from being too large or too small, affecting the appearance and sealing strength of the battery cell 100.

[0084] As Figure 5 shown, in some embodiments, the packaging body 20 includes two encapsulation half-films 24. Each encapsulation half-film 24 includes an outer layer 241, an intermediate layer 242, and an inner layer 243 arranged in sequence. The inner layers 243 of the two encapsulation half-films 24 of the avoidance section 222 are arranged at intervals, and the inner layers 243 of the two encapsulation half-films 24 of the edge-sealing section 221 are connected to each other.

[0085] As Figure 5 shown, each encapsulation half-film 24 includes an outer layer 241, an intermediate layer 242, and an inner layer 243. The outer layer 241 can be nylon, which can provide good mechanical strength and flexibility, and at the same time has corrosion resistance; the intermediate layer 242 can be pure aluminum foil or aluminum alloy foil, which can effectively isolate water and oxygen in the air, prevent them from entering the battery interior, protect the performance and life of the battery, and at the same time provide a certain electromagnetic shielding effect to prevent external electromagnetic interference; the inner layer 243 can be polypropylene (CPP). During the hot pressing process, the adhesive layer (such as PP) in the CPP material of the inner layer melts at a certain temperature and pressure, so that the adhesive layers of the two inner layer materials come into contact and fuse with each other.

[0086] During the hot pressing process, the heat-sealing head 30 presses the encapsulation part 21, and the part corresponding to the avoidance groove 31 of the heat-sealing head 30 is not hot-pressed. The inner layers 243 of the two encapsulation half-films 24 are arranged at intervals, thus forming the avoidance section 222, and the other parts form the edge-sealing section 221 and the second encapsulation area 23.

[0087] Thereby, the pressure that the first encapsulation area 22 can withstand is reduced. When thermal runaway occurs, the sealing edge at the first encapsulation area 22 will be broken first, and high-pressure gas and heat can be quickly discharged from the first encapsulation area 22, realizing a fixed exhaust position for thermal runaway, guiding the pressure to be discharged in a specific direction, improving the reliability of the battery cell, and enhancing the safety of the system.

[0088] As Figure 3 and Figure 4 shown, in some embodiments, in the extending direction of the encapsulation part 21, the length of the first encapsulation area 22 is less than the length of the second encapsulation area 23.

[0089] In the first direction F1, the length of the first encapsulation area 22 is less than the length of the second encapsulation area 23. Thereby, the reliability of the sealing edge of the encapsulation part 21 is improved, the probability of leakage of the battery cell 100 during normal use is reduced, and the service life of the battery cell 100 is increased.

[0090] As Figure 3 、 Figure 6 、 Figure 8 shown, in some embodiments, the electrode assembly 10 includes a main body part 11 and two tab parts 12. The two tab parts 12 are located on one side of the main body part 11, and the first encapsulation area 22 is located on the other side of the main body part 11.

[0091] As Figure 3 、 Figure 6 、 Figure 8 shown, the tab part 12 is located on one side of the main body part 11 in the second direction F2, and the first encapsulation area 22 is located on the other side of the main body part 11 in the second direction F2. Thereby, when thermal runaway occurs, the first encapsulation area 22 can guide the gas to be discharged from the side opposite to the tab part 12, avoiding the impact of high-temperature and high-pressure gas on the tab part 12 and reducing the risk of high-voltage short circuit.

[0092] Of course, for some battery cells 100 that do not require hemming on the side edges in the first direction F1, the first encapsulation area 22 can also be located on one side of the main body part 11 in the first direction F1.

[0093] As Figure 10 shown, in some embodiments, the electrode assembly 10 includes a main body part 11 and two tab parts 12. The two tab parts 12 are located on at least one side of the main body part 11, and the first encapsulation area 22 is located on the side of the main body part 11 where the tab parts 12 are provided.

[0094] As Figure 10As shown in the figure, two tab portions 12 are located on both sides of the main body portion 11 in the second direction F2, and the first encapsulation area 22 is located on one side of the main body portion 11 in the second direction F2. Thus, when thermal runaway occurs, the sealing edge at the first encapsulation area 22 will be broken first, and high-pressure gas and heat can be quickly discharged from the first encapsulation area 22, realizing a fixed exhaust position for thermal runaway, guiding the pressure to be discharged directionally, and improving the reliability of the battery cell 100.

[0095] The second aspect of the present application provides a battery device 1000, and the battery device 1000 includes the battery cell 100 according to the embodiment of the present application. Thus, by adopting the above battery cell 100, a fixed exhaust position for thermal runaway can be realized, the pressure can be guided to be discharged directionally, and the reliability of the battery device 1000 can be improved.

[0096] The third aspect of the present application provides an energy storage device 3000, and the energy storage device 3000 includes the battery device 1000 according to the embodiment of the second aspect of the present application that is used to store electric energy and can provide electric energy.

[0097] Since the energy storage device includes the above battery device 1000, the reliability of the use of the battery device and the energy storage device can be improved.

[0098] Next, a specific embodiment of the present application will be exemplified.

[0099] As Figure 2 shown, the battery device 1000 includes a battery cell 100 and a box body 500. The battery cell 100 is arranged in the box body 500, and the battery cell 100 is a battery cell that uses a soft packaging film as the packaging body 20.

[0100] The battery cell 100 includes an electrode assembly 10 and a packaging body 20. The electrode assembly 10 includes a main body portion 11 and tab portions 12. The packaging body 20 is wrapped outside the electrode assembly 10. The packaging body 20 has an encapsulation portion 21. The encapsulation portion 21 includes a first encapsulation area 22 and a second encapsulation area 23. The first encapsulation area 22 and the tab portions 12 are arranged opposite to each other on both sides of the main body portion 11.

[0101] A part of the first encapsulation area 22 is encapsulated to form a sealing edge segment 221, and another part of the first encapsulation area 22 is not encapsulated to form an avoidance segment 222. The first encapsulation area 22 includes two sealing edge segments 221 and an avoidance segment 222. The avoidance segment 222 is located between the two sealing edge segments 221. The thickness of the avoidance segment 222 is greater than the thickness of the sealing edge segment 221. Among them, in the second direction F2, the width of the first encapsulation area 22 is W0, and the maximum width of the avoidance segment 222 is W1, and W1 / W0 is 0.55.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present application, and they should all be covered within the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that, Comprising: An electrode assembly (10); A packaging body (20), covering the outside of the electrode assembly (10), the packaging body (20) having a packaging portion (21) extending along the outer periphery of the electrode assembly (10), in the extending direction of the packaging portion (21), the packaging portion (21) includes a first packaging area (22) and a second packaging area (23), The first packaging area (22) includes a sealing edge section (221) and an avoidance section (222) arranged along the width direction of the packaging portion (21), a part of the first packaging area (22) is packaged to form the sealing edge section (221), another part of the first packaging area (22) is not packaged to form the avoidance section (222), and the thickness of the avoidance section (222) is greater than the thickness of the sealing edge section (221), In the width direction of the packaging portion (21), the width of the sealing edge section (221) is smaller than the width of the second packaging area (23) after packaging.

2. The battery cell according to claim 1, characterized in that In the width direction of the packaging portion (21), the width of the first packaging area (22) is W0, the maximum width of the avoidance section (222) is W1, and 0.1 ≤ W1 / W0 ≤ 0.

7.

3. The battery cell according to claim 1, characterized in that In the width direction of the packaging portion (21), the avoidance section (222) is located in the middle of the first packaging area (22).

4. The battery cell according to claim 1, characterized in that The avoidance section (222) is closer to or farther from the electrode assembly (10) relative to the sealing edge section (221).

5. The battery cell according to claim 1, characterized in that The maximum thickness of the avoidance section (222) is H1, the maximum thickness of the sealing edge section (221) is H2, and 0.05 ≤ H2 / H1 ≤ 0.

4.

6. The battery cell according to claim 5, characterized in that The maximum thickness of the sealing edge section (221) is the same as the maximum thickness of the second packaging area (23).

7. The battery cell according to claim 1, characterized in that The packaging body (20) includes two packaging semi-films (24), each packaging semi-film (24) includes an outer layer (241), an intermediate layer (242) and an inner layer (243) arranged in sequence, the inner layers (243) of the two packaging semi-films (24) of the avoidance section (222) are arranged at intervals, and the inner layers (243) of the two packaging semi-films (24) of the sealing edge section (221) are connected to each other.

8. The battery cell according to claim 1, characterized in that In the extending direction of the packaging portion (21), the length of the first packaging area (22) is smaller than the length of the second packaging area (23).

9. The battery cell according to any one of claims 1-8, characterized in that The electrode assembly (10) includes a main body part and two pole ear parts, the two pole ear parts are located on one side of the main body part, and the first packaging area (22) is located on the other side of the main body part.

10. The battery cell according to any one of claims 1-8, characterized in that the electrode assembly (10) includes a main body portion and two tab portions, the two tab portions are located on at least one side of the main body portion, and the first encapsulation region (22) is located on the side of the main body portion where the tab portions are provided.

11. A battery device (1000), characterized in that, including the battery cell according to any one of claims 1-10.

12. An energy storage device (3000), characterized in that, including the battery device (1000) according to claim 11.

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