Electrode assembly, battery cell and method of assembling the same, battery pack

Abstract

The application discloses an electrode assembly, a battery monomer and an assembling method thereof, and a battery pack, and belongs to the technical field of batteries. A plurality of bonding parts are arranged at intervals on the surface of an electrode body, so that the electrode assembly can be stably fixed in the interior of a battery shell. The plurality of bonding parts are arranged at intervals on the surface of the electrode body, and the interval between two adjacent bonding parts is configured to absorb the expansion stress generated by the battery monomer in the cyclic charging and discharging process. The bonding part is arranged in protrusion relative to the surface of the electrode body, and the local protruding structure formed by each bonding part plays a lubricating and guiding role in the process of installing the electrode assembly in the interior of the battery shell, so that the installation process of the electrode assembly is more smooth.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to an electrode assembly, a battery cell and its assembly method, and a battery pack. Background Technology

[0002] A cylindrical battery cell includes a battery casing and an electrode assembly housed within the battery casing, with a gap between the electrode assembly and the battery casing. During the assembly process, the electrode assembly is difficult to center properly within the battery casing, causing it to deviate to the left or right of the battery casing, which in turn affects the electrochemical and safety performance of the battery cell. Summary of the Invention

[0003] This application provides an electrode assembly, a battery cell, an assembly method thereof, and a battery pack.

[0004] To achieve the above objectives, according to a first aspect of this application, an electrode assembly is provided, which is adapted to be installed within a battery casing. The electrode assembly includes: Electrode body; multiple adhesive portions are spaced apart on the surface of the electrode body, and the adhesive portions protrude relative to the surface of the electrode body.

[0005] By providing multiple adhesive portions at intervals on the surface of the electrode body, the electrode assembly can be stably fixed inside the battery casing. These adhesive portions are spaced apart on the surface of the electrode body, meaning they are not fully enclosed. The spacing between adjacent adhesive portions is configured to absorb the expansion stress generated by the battery cells during cyclic charging and discharging, preventing damage to the internal structure of the battery cells. Furthermore, each adhesive portion protrudes from the surface of the electrode body, and the localized protrusion formed by each adhesive portion acts as a lubricant and guide during the installation of the electrode assembly into the battery casing. Compared to related technologies that use several layers of tape to fix the electrode body, the electrode assembly provided in this embodiment exhibits lower overall friction due to the multiple adhesive portions, resulting in a smoother installation process.

[0006] Optionally, the electrode body is configured as a core assembly, the core assembly having a plurality of adhesive portions spaced apart along the circumferential or axial direction; wherein the shape of the adhesive portions includes dots, and each adhesive portion assembly includes a plurality of adhesive portions spaced apart; or, wherein the shape of the adhesive portions includes lines, and each adhesive portion assembly includes at least one adhesive portion, to facilitate dispensing operations.

[0007] Optionally, the core assembly has multiple bonding portions spaced apart circumferentially. These bonding portions extend linearly, in a zigzag, sinusoidal, or helical manner along the axial direction of the core assembly. When the bonding portions extend linearly, it helps to provide uniform constraint along the axial direction of the electrode body. When the bonding portions extend in a zigzag, sinusoidal, or helical manner, it allows for the placement of multiple bonding portions within a wider angular range on the outer circumference of the electrode body, thereby helping to prevent electrode body misalignment.

[0008] Optionally, the height of the adhesive assembly extending along the axial direction of the core assembly is h1, and the height of the core assembly is h2; where 0.7 ≤ h1 / h2 ≤ 0.9. When h1 / h2 is less than 0.7, the adhesive assembly will not cover a large height space in the axial direction of the core assembly, making it difficult for multiple fixing parts to stably fix the electrode body inside the battery casing. When h1 / h2 is greater than 0.9, although it is beneficial to stably fix the electrode body inside the battery casing, it will result in a large total coverage area of ​​multiple adhesive parts on the outer surface of the electrode body, making it difficult to install the electrode assembly inside the battery casing.

[0009] Optionally, the electrode body has n bonding portion combinations, where 4 ≤ n ≤ 12, and n is a positive integer. When the number n of bonding portion combinations spaced apart along the circumferential direction of the core assembly is set to less than 4, that is, the central angle formed by adjacent bonding portion combinations and the central axis of the core assembly is set to greater than 90°, the core assembly is prone to tilting under external forces after being installed in the battery casing. When the number n of bonding portion combinations spaced apart along the circumferential direction of the core assembly is set to greater than 12, although this improves the stability of the electrode assembly after installation in the battery casing, it leads to excessively long dispensing times for forming multiple bonding portion combinations, thus increasing manufacturing costs.

[0010] Optionally, each adhesive assembly is configured to extend along a first direction, which is at an angle to the axial direction of the core assembly.

[0011] By setting the extension direction of each adhesive assembly at an angle to the axial direction of the core assembly, that is, by setting each adhesive assembly at an angle on the outer surface of the core assembly, the adhesive assembly can cover a wider angle range within the 360° angle range of the outer circumference of the core assembly, thereby helping to prevent the core assembly from shifting.

[0012] Optionally, the bonding assembly is configured to either close around the outer surface of the electrode body or not close around the outer surface of the electrode body.

[0013] Optionally, the angle between the first direction and the axial direction of the core assembly is 30° - 70°, so that the combined adhesive force provided by the adhesive assembly can be basically balanced by the components of the force decomposed along the axial and radial directions of the core assembly, thereby providing both radial expansion constraint force and axial offset constraint force simultaneously.

[0014] Optionally, the orthographic projection of the adhesive portion onto the surface of the electrode body is circular or elliptical, and the diameter of the adhesive portion is 1.0 mm to 3.0 mm; or, the shape of the adhesive portion includes a line shape, and the width of the adhesive portion ranges from 1.0 mm to 3.0 mm.

[0015] Optionally, the adhesive portion is made of an elastic colloid with an elastic compression range of 0.05 mm to 0.5 mm; and / or, the thermal conductivity of the adhesive portion ranges from 0.2 W / (m·K) to 3.0 W / (m·K).

[0016] Optionally, the bonding material includes at least one of silicone, polyurethane adhesive, thermally conductive gel, and UV adhesive.

[0017] Optionally, the ratio of the total area of ​​the multiple adhesive portions covering the outer surface of the electrode body to the surface area of ​​the outer surface of the electrode body is 0.05 to 0.5.

[0018] Optionally, the height of the adhesive portion protruding from the surface of the electrode body is h, and the assembly interval between the electrode body and the battery casing is t, where 0.5mm ≤ th ≤ 0.8mm.

[0019] Optionally, multiple adhesive portions protrude at the same height relative to the surface of the electrode body to avoid excessive local adhesive force, which could lead to tilting of the electrode assembly.

[0020] Alternatively, multiple adhesive portions may be formed by dispensing adhesive onto the electrode body.

[0021] According to a second aspect of this application, a battery cell is provided, comprising: the electrode assembly as described above; and a battery housing, wherein the electrode assembly is fixed within the battery housing.

[0022] According to a third aspect of this application, a method for assembling a battery cell is provided, applicable to assembling the battery cells described above, the assembly method comprising: Provide electrode body; Apply adhesive to the surface of the electrode body to form multiple bonding portions; Curing multiple adhesive portions on the surface of the electrode body after dispensing; The cured electrode body is placed into the battery casing.

[0023] According to a fourth aspect of this application, a battery pack is provided, including a plurality of battery cells as described above and a battery case, the battery case being configured to accommodate the plurality of battery cells.

[0024] In the electrode assembly of this application embodiment, multiple adhesive portions are spaced apart on the surface of the electrode body to stably fix the electrode assembly inside the battery casing. These adhesive portions are distributed spaced apart on the surface of the electrode body, and the spacing between adjacent adhesive portions is configured to absorb the expansion stress generated by the battery cells during cyclic charging and discharging, preventing damage to the internal structure of the battery cells. Furthermore, each adhesive portion protrudes from the surface of the electrode body, and the local protrusion structure formed by each adhesive portion plays a lubricating and guiding role during the installation of the electrode assembly into the battery casing. Compared to the structure in related technologies that uses several layers of tape to fix the electrode body, the electrode assembly provided in this application embodiment has less overall friction from the multiple adhesive portions, thus making the installation process of the electrode assembly smoother.

[0025] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0028] Figure 1 This is a schematic diagram of the overall structure of a battery cell provided in an exemplary embodiment of this disclosure; Figure 2 yes Figure 1 A magnified view of a portion of the image; Figure 3A This is a front view structural diagram of the electrode assembly of a battery cell provided in the first exemplary embodiment of this disclosure; Figure 3B This is a front view structural schematic diagram of the electrode assembly of a battery cell provided in the second exemplary embodiment of this disclosure; Figure 4 This is a front view structural diagram of the electrode assembly of a battery cell provided in the third exemplary embodiment of this disclosure; Figure 5AThis is a schematic front view of the bonding portion of the electrode assembly of a battery cell provided in the first exemplary embodiment of this disclosure. Figure 5B This is a front view structural schematic diagram of the bonding portion of the electrode assembly of a battery cell provided in the second exemplary embodiment of this disclosure; Figure 5C This is a front view structural schematic diagram of the bonding portion of the electrode assembly of the battery cell provided in the third exemplary embodiment of this disclosure; Figure 5D This is a front view structural schematic diagram of the bonding portion of the electrode assembly of the battery cell provided in the fourth exemplary embodiment of this disclosure. Figure 6 This is a front view structural diagram of the electrode assembly of a battery cell provided in the fourth exemplary embodiment of this disclosure; Figure 7 This is a front view structural diagram of the electrode assembly of a battery cell provided in the fifth exemplary embodiment of this disclosure; Figure 8 This is a front view structural diagram of the electrode assembly of a battery cell provided in the sixth exemplary embodiment of this disclosure.

[0029] Explanation of reference numerals in the attached figures: 100. Battery cell; 10. Electrode assembly; 1. Battery casing; 2. Electrode body; 3. Adhesive part; 31. Adhesive part assembly. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0031] A cylindrical battery cell includes a battery casing and an electrode assembly housed within the battery casing, with a gap between the electrode assembly and the battery casing. During the assembly process, the electrode assembly is difficult to position centrally within the battery casing, resulting in it being offset to the left on one side of the battery casing, or to the right on the other side, or tilted inside the battery casing. This can negatively impact the electrochemical and safety performance of the battery cell.

[0032] In related technologies, several layers of tape are wrapped around the outer surface of the electrode assembly to increase its outer diameter, thereby shortening the gap between the electrode assembly and the battery casing. However, this method has the following drawbacks: First, wrapping the electrode assembly with several layers of tape increases its outer diameter, making it difficult to install the electrode assembly into the battery casing. Second, the battery cells expand during cyclic charging and discharging. Due to the insufficient gap between the electrode assembly and the battery casing, the expanded battery cells press against the rigid battery casing, generating expansion stress. This can lead to tape breakage and localized stress concentration in the electrode assembly, damaging the internal structure of the battery cells.

[0033] In view of this, this application provides a battery pack that can be used in electrical devices that use the battery pack as a power source or in various energy storage systems that use the battery pack as an energy storage element.

[0034] Electrical devices that use battery packs as a power source can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc. Taking vehicles as an example, the vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.

[0035] The battery pack includes a housing and an assembly of one or more battery cells disposed within the housing. The housing may be part of the chassis structure of the electric vehicle. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0036] A battery cell assembly is typically formed by arranging multiple battery cells. As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module.

[0037] As an example, a battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc.

[0038] like Figure 1 As shown, the battery cell 100 includes a battery casing 1 and a core pack.

[0039] The battery casing 1 may include a single-pass battery casing, i.e., the battery casing has an opening at its top. The battery casing 1 includes a bottom wall and a side wall connected together, with the bottom wall connected to the bottom end of the side wall. A cover plate is welded to the top opening of the battery casing. One of the cover plate and the battery casing serves as the negative electrode of the battery cell, and the other of the cover plate and the battery casing serves as the positive electrode of the battery cell. The battery casing 1 has a receiving cavity, and the core pack is installed in the receiving cavity inside the battery casing 1. The battery casing 1 is configured as a hollow cylinder, and suitable materials for manufacturing the battery casing 1 include aluminum, aluminum alloy, nickel-plated steel sheet, and stainless steel.

[0040] The core package includes an electrode body 2 and an electrolyte. The electrode body 2 comprises multiple positive electrode plates, multiple separators, and multiple negative electrode plates formed by winding, or multiple positive electrode plates, multiple separators, and multiple negative electrode plates formed by stacking. Each separator is disposed between each positive electrode plate and each negative electrode plate to provide electrical isolation. The electrolyte fills the electrode body 2. The electrode body 2 can be a cylindrical electrode formed by winding, or a square electrode formed by stacking or winding.

[0041] This application also provides an electrode assembly 10, which is installed in the inner cavity of a battery casing 1. The electrode assembly 10 includes an electrode body 2 and a plurality of adhesive portions 3. The adhesive portions 3 are spaced apart on the surface of the electrode body 2 to stably fix the electrode assembly 10 inside the battery casing 1. The adhesive portions 3 are spaced apart on the surface of the electrode body 2, meaning they are not fully enclosed. The spacing between adjacent adhesive portions 3 is configured to cope with the expansion stress generated by the battery cell 100 during cyclic charging and discharging, thus preventing damage to the internal structure of the battery cell 100.

[0042] Furthermore, the adhesive portion 3 protrudes from the surface of the electrode body 2. The local protrusion structure formed by each adhesive portion 3 plays a lubricating and guiding role in the process of installing the electrode assembly 10 into the battery casing 1. Compared with the structure in the related art that wraps several layers of tape around the surface of the electrode body for fixation, the overall friction formed by the multiple adhesive portions 3 in the electrode assembly 10 provided in this application embodiment is smaller, thereby making the installation process of the electrode assembly 10 smoother.

[0043] In some embodiments, the adhesive portion 3 includes a colloid, wherein the colloid is selected to possess insulating properties, resistance to electrolyte corrosion, thermal conductivity, and elasticity. Suitable colloid materials include silicone, polyurethane adhesive, thermally conductive gel, and UV adhesive. It is understood that when the colloid is thermally conductive, the multiple adhesive portions 3 are also suitable for transferring heat from the electrode body 2 to the battery cell 100, and the spacing between adjacent adhesive portions 3 is also suitable for heat dissipation, which is beneficial for improving the internal heat dissipation performance of the battery cell 100. When the colloid is resistant to electrolyte corrosion, it can withstand long-term corrosion from the internal electrolyte of the battery cell 100, thereby avoiding swelling, cracking, and detachment, and can maintain the adhesive strength and structural integrity of the colloid for a long time, preventing loosening and misalignment of the electrode assembly due to colloid failure, extending the service life of the battery cell 100, and meeting the requirements of long-term cyclic use of the battery cell.

[0044] In some embodiments, the adhesive portion 3 is configured as an elastic colloid, the elastic compression range of which is 0.05 mm to 0.5 mm. The original thickness of the adhesive portion 3 of the electrode assembly 10 is set as d1, and the actual thickness of the adhesive portion 3 after the electrode assembly 10 is installed in the inner cavity of the battery housing 1 and is in a compressed state is set as d2. The elastic compression of the elastic colloid is defined as the difference between the original thickness d1 of the adhesive portion 3 and the actual thickness d2 of the adhesive portion 3 after compression. It should be noted that when the electrode assembly 10 is installed in the inner cavity of the battery housing 1, and the electrode body 2 is in a normal state, the multiple adhesive portions 3 are in an uncompressed state, and an installation gap is formed between the multiple adhesive portions 3 and the battery housing 1. When the electrode body 2 expands, the adhesive portions 3 located on the electrode body 2 contact the battery housing 1 and are compressed.

[0045] Understandably, when the elastic compression of the elastic colloid is set to less than 0.05 mm, the elastic compression provided by the multiple bonding portions 3 is insufficient, resulting in insufficient elastic deformation force. Consequently, the electrode assembly 10 still faces the problem of being difficult to install into the battery casing 1. Furthermore, when the battery cell 100 expands during cyclic charging and discharging, the multiple bonding portions 3 cannot eliminate the cyclic expansion stress, which can still damage the internal structure of the battery cell 100. When the elastic compression of the elastic colloid is set to greater than 0.5 mm, the elastic colloid itself becomes too soft, making it difficult for the multiple bonding portions 3 to provide effective rigid support. This causes the electrode assembly to easily shake inside the battery casing 1, especially when the battery cell 100 is under severe vibration. For example, the compression of the elastic colloid can be 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, or any value between any two of these values, or a range between any two of these values.

[0046] In some embodiments, the thermal conductivity of the adhesive portion 3 ranges from 0.2 W / (m·K) to 3.0 W / (m·K). It is understood that the adhesive portion 3 serves as a thermally conductive medium between the electrode body 2 and the battery casing 1. When the thermal conductivity of the adhesive portion 3 is set to less than 0.2 W / (m·K), it becomes difficult for the heat from the electrode body 2 to be transferred to the battery casing 1 for heat exchange. The main component of the adhesive portion 3 is a colloid, which is itself a poor conductor of heat. When the thermal conductivity of the adhesive portion 3 is set to greater than 3.0 W / (m·K), a large amount of thermally conductive filler, such as alumina, boron nitride, and magnesium oxide, must be added. Adding a large amount of thermally conductive filler to the colloid disrupts the continuity of the polymer chains in the colloid, leading to a decrease in elasticity, an increase in hardness, and a decrease in compressibility. While the colloid can still conduct heat, it loses its core function of absorbing expansion and vibration. Consequently, after the battery cell 100 undergoes cyclic charging and discharging and expands, multiple adhesive portions 3 will form a rigid compression between the electrode body 2 and the battery casing 1, thereby damaging the electrode body 2. As examples, the thermal conductivity of the adhesive portion 3 is 0.2 W / (m·K), 0.5 W / (m·K), 0.8 W / (m·K), 1.0 W / (m·K), 1.5 W / (m·K), 1.8 W / (m·K), 2.0 W / (m·K), 2.5 W / (m·K), 3.0 W / (m·K), and any value between any two of the above values ​​or a range between any two of the above values.

[0047] In some embodiments, the ratio of the total area covered by the plurality of adhesive portions 3 on the outer surface of the electrode body 2 to the surface area of ​​the electrode body 2 is 0.05 to 0.5. It is understood that the plurality of adhesive portions 3 serve as the bonding structure for bonding the electrode body 2 and the battery casing 1. If the ratio of the total area covered by the plurality of adhesive portions 3 on the outer surface of the electrode body 2 to the surface area of ​​the electrode body 2 is set to less than 0.05, the fixing force provided by the plurality of adhesive portions 3 is insufficient, which can lead to the battery cell 100 being subjected to severe vibration, making it easy for the electrode body 2 to loosen from the battery casing 1. Conversely, when the ratio of the total area covered by the plurality of adhesive portions 3 on the outer surface of the electrode body 2 to the surface area of ​​the electrode body 2 is set to greater than 0.5, the insertion resistance provided by the plurality of adhesive portions 3 will significantly increase during the installation of the electrode assembly 10 into the battery casing 1, making it difficult to install the electrode assembly 10 into the battery casing 1. As some examples, the ratio of the total area covered by the multiple adhesive portions 3 on the outer surface of the electrode body 2 to the surface area of ​​the electrode body 2 is 0.05 to 0.15. This is suitable for electrode bodies 2 with small gaps between the electrode body 2 and the battery housing 1 and low expansion rates, where the multiple adhesive portions 3 can provide a mild fixing effect. As other examples, the ratio of the total area covered by the multiple adhesive portions 3 on the outer surface of the electrode body 2 to the surface area of ​​the electrode body 2 is 0.15 to 0.3. This is suitable for electrode bodies 2 with moderate gaps between the electrode body 2 and the battery housing 1 and moderate expansion rates, where the multiple adhesive portions 3 provide a moderate fixing effect. As still other examples, the ratio of the total area covered by the multiple adhesive portions 3 on the outer surface of the electrode body 2 to the surface area of ​​the electrode body 2 is 0.3 to 0.5. This is suitable for battery cells 100 used in scenarios with extremely high vibration requirements, where the multiple adhesive portions 3 can provide a strong fixing effect, but this will increase the resistance during the installation of the electrode assembly 10 into the battery housing 1. As another example, the ratio of the total area of ​​the multiple adhesive portions 3 covering the outer surface of the electrode body 2 to the surface area of ​​the electrode body 2 is 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, or any two of the above values ​​or a range between any two of the above values.

[0048] In some embodiments, such as Figure 1 and Figure 2As shown, the height of the protrusion of the adhesive part 3 relative to the outer surface of the electrode body 2 is h, and the assembly gap between the electrode body 2 and the battery housing 1 is t. The assembly gap t and the height h of the protrusion of the adhesive part 3 satisfy the condition: 0.5mm ≤ th ≤ 0.8mm, thus allowing the electrode assembly 10 to be properly installed inside the battery housing 1. It is understandable that when th is less than 0.5mm, i.e., the gap between the adhesive part 3 and the battery housing 1 is too small, the resistance to installing the electrode assembly 10 into the battery housing 1 increases significantly, leading to installation difficulties. When th is greater than 0.8mm, i.e., the gap between the adhesive part 3 and the battery housing 1 is too large, the occupancy rate of the electrode body 2 within the battery housing 1 decreases, thereby affecting the energy density of the battery cell 100. As some examples, th can be 0.5, 0.6, 0.7, 0.8, or any value between any two of the above, or a range between any two of the above values.

[0049] In some embodiments, all the adhesive portions 3 on the electrode body 2 protrude at the same height on the surface of the electrode body 2, so that the bonding force between the multiple adhesive portions 3 and the battery casing 1 is basically the same, avoiding the local adhesive portions 3 protruding at a greater height, thus making the bonding force between them and the battery casing 1 more stable, which would make the electrode assembly 10 prone to tilting, which is not conducive to maintaining the stability of the electrical performance of the battery cell.

[0050] In some embodiments, the electrode body 2 is configured as a core assembly, i.e., a plurality of positive electrode sheets, a plurality of separators, and a plurality of negative electrode sheets are wound together to form a core assembly. The core assembly is provided with a plurality of adhesive portion assemblies 31 spaced apart along the circumferential or axial direction, wherein the plurality of adhesive portion assemblies 31 have substantially the same shape and external dimensions.

[0051] As some examples, such as Figure 3A and Figure 3B Multiple adhesive portions 3 are configured as dots, and each adhesive portion assembly 31 includes multiple adhesive portions 3 that are evenly spaced. Multiple adhesive portion assemblies 31 are configured to extend in the same direction. The extension direction of the adhesive portion assembly 31 can be the axial direction of the electrode body 2, or the extension direction of the adhesive portion assembly 31 can be set at an angle to the axial direction of the electrode body 2.

[0052] For example, when the adhesive assembly 31 is configured to extend along the axial direction of the electrode body 2, and multiple adhesive assemblies 31 are configured to be arranged circumferentially spaced along the electrode body 2, a single adhesive assembly 31 provides axial fixation to prevent the core assembly from axially displacing after being installed inside the battery housing 1, and multiple adhesive assemblies 31 provide circumferential fixation to prevent the core assembly from circumferentially displacing after being installed inside the battery housing 1, and multiple adhesive assemblies 3 are evenly spaced on the outer surface of the core assembly to prevent uneven local stress on the core assembly from causing the core assembly to tilt.

[0053] Among them, such as Figure 5A , Figure 5B , Figure 5C and Figure 5D As shown, the adhesive assembly 31 extends in a straight line, a zigzag line, a sinusoidal line, or a spiral line along the axial direction of the core assembly. It is understood that when the adhesive assembly 31 extends in a straight line, it helps to provide a uniform constraint along the axial direction of the electrode body 2. When the adhesive assembly 31 extends in a zigzag line, a sinusoidal line, or a spiral line, it helps to provide multiple adhesive portions 3 within a larger angular range across the 360° area of ​​the outer circumference of the electrode body 2, thereby helping to prevent the electrode body 2 from shifting.

[0054] As some examples, such as Figure 3B As shown, when the adhesive portion 3 is set as a dot, the height of the adhesive portion assembly 31 extending along the axial direction of the core assembly is h1, and the height of the core assembly is h2, where 0.7 ≤ h1 / h2 ≤ 0.9. It is understandable that when h1 / h2 is less than 0.7, the height space not covered by the adhesive portion assembly 31 in the axial direction of the core assembly is relatively large, making it difficult for the multiple adhesive portions 3 to stably fix the electrode body 2 inside the battery housing 1. When h1 / h2 is greater than 0.9, although it is beneficial to stably fix the electrode body 2 inside the battery housing 1, it results in a larger total coverage area of ​​the multiple adhesive portions 3 on the outer surface of the electrode body 2, making it difficult to install the electrode assembly 10 inside the battery housing 1. As some examples, h1 / h2 can be 0.7, 0.8, 0.9, or any value between any two of the above, or a range between any two of the above values.

[0055] As examples, the number of adhesive assemblies 31 spaced apart along the circumferential direction of the electrode body 2 is n, where 4 ≤ n ≤ 12, and n is a positive integer, with adjacent adhesive assemblies 31 maintaining an equal spacing. It is understood that if the number n of adhesive assemblies 31 spaced apart along the circumferential direction of the electrode body 2 is less than 4, that is, the central angle formed by adjacent adhesive assemblies 31 and the central axis of the electrode body 2 is greater than 90°, the electrode assembly 10 is prone to tilting under external force after being installed in the battery casing 1. When the number n of adhesive assemblies 31 spaced apart along the circumferential direction of the electrode body 2 is greater than 12, although it helps improve the stability of the electrode assembly 10 after being installed in the battery casing 1, it leads to excessively long dispensing time for forming multiple adhesive assemblies 31, thereby increasing manufacturing costs. As specific examples, the number n of adhesive assemblies 31 spaced apart along the circumferential direction of the core assembly can be 4, 5, 6, 7, 8, 9, 10, 11, or 12. The central angle formed by the adjacent adhesive part assembly 31 and the central axis of the core assembly can be 30°, 45°, 60° or 90°.

[0056] As some other examples, such as Figure 4 As shown, the adhesive portion 3 is configured as a line, and each adhesive portion assembly 31 includes at least one adhesive portion assembly 31. The linear structure of the adhesive portion 3 is beneficial to increasing the total coverage area of ​​the multiple adhesive portions 3 on the outer surface of the electrode body 2, thereby enhancing the adhesive force.

[0057] As one example, the linear adhesive assembly 31 is configured to extend along the axial direction of the core assembly, thereby enabling the adhesive assembly 31 to provide the maximum effective projection height in the axial direction, which in turn helps to improve the bonding stability of the electrode body 2 in the axial direction. Furthermore, the linear adhesive assembly 31 helps to improve dispensing efficiency.

[0058] Each linear bonding assembly 31 extends in a straight line, a zigzag line, a sinusoidal line, or a spiral line along the axial direction of the core assembly.

[0059] As some examples, please refer to... Figure 4Each linear bonding portion 3 extends to a height h3 along the axial direction of the core assembly, and the height of the core assembly is h2, where 0.7 ≤ h3 / h2 ≤ 0.9. It is understandable that when h3 / h2 is less than 0.7, the uncovered height space in the axial direction of the core assembly by each bonding portion 3 is relatively large, making it difficult for multiple bonding portions 3 to stably fix the electrode body 2 inside the battery housing 1. When h1 / h2 is greater than 0.9, although it is beneficial to stably fix the electrode body 2 inside the battery housing 1, it results in a larger total coverage area of ​​multiple bonding portions 3 on the outer surface of the electrode body 2, making it difficult to install the electrode assembly 10 inside the battery housing 1. As examples, h3 / h2 can be 0.7, 0.8, 0.9, or any value between any two of the above, or a range between any two of the above values.

[0060] As examples, the adhesive portions 3 are arranged in a linear pattern, and the number of adhesive portions 3 spaced apart along the circumferential direction of the core assembly is m, where 4 ≤ m ≤ 12, and m is a positive integer. Adjacent adhesive portions 3 are evenly spaced. It is understood that if the number m of adhesive portions 3 spaced apart along the circumferential direction of the core assembly is less than 4, that is, the central angle formed by adjacent adhesive portions 3 and the central axis of the core assembly is greater than 90°, the core assembly is prone to tilting under external forces after being installed in the battery housing 1. When the number m of adhesive portions 3 spaced apart along the circumferential direction of the core assembly is greater than 12, although it is beneficial to improve the stability of the electrode assembly 10 after being installed in the battery housing 1, it leads to excessively long dispensing time for forming multiple adhesive portions 3, thereby increasing manufacturing costs. As specific examples, the number m of adhesive portions 3 spaced apart along the circumferential direction of the core assembly can be 4, 5, 6, 7, 8, 9, 10, 11, or 12. The central angle formed by the adjacent adhesive portion 3 and the central axis of the core assembly can be 30°, 45°, 60° or 90°.

[0061] In some embodiments, each adhesive assembly 31 is configured to extend along a first direction, which is at an angle to the axial direction of the core assembly. By setting the extension direction of each adhesive assembly 31 at an angle to the axial direction of the core assembly, that is, by setting each adhesive assembly 31 at an angle on the outer surface of the core assembly, the adhesive assembly 31 can cover a wider angle range within a 360° angle range of the outer peripheral surface of the core assembly, thereby helping to prevent the core assembly from shifting.

[0062] As some examples, such as Figures 6 to 8As shown, the core assembly has multiple adhesive portion assemblies 31, each extending along a first direction, and the multiple adhesive portion assemblies 31 are arranged to be spaced apart along the axial and circumferential directions. The adhesive portion assembly 31 may include multiple point-like adhesive portions 3, or at least a line-like adhesive portion 3. The angle between the first direction and the axial direction of the core assembly is 30° to 70°, so that the combined adhesive force provided by the adhesive portion assembly 31, when decomposed along the axial and radial directions of the core assembly, can maintain a basic balance, thereby simultaneously providing radial expansion constraint force and axial offset constraint force. As some specific embodiments, the adhesive portion assembly 31 extends along the first direction, and the angle between the first direction and the axial direction of the core assembly can be 30°, 40°, 45°, 50°, 60°, 70°, or any two of the above angles, or a range between any two of the above angles.

[0063] In some embodiments, when the extending direction of the adhesive assembly 31 is set at an angle to the axial direction of the core assembly, such as Figure 6 As shown, the adhesive assembly 31 can be configured to close around the outer surface of the core assembly, or as... Figure 7 and Figure 8 As shown, the adhesive assembly 31 can also be configured to be non-closedly surrounding the outer surface of the core assembly. For example, when the adhesive assembly 31 is configured to be closedly surrounding the outer surface of the core assembly, only one adhesive assembly 31 is provided along the outer circumferential surface of the core assembly, and multiple adhesive assemblies 31 are spaced apart along the axial direction of the core assembly. When the adhesive assembly 31 is configured to be non-closedly surrounding the outer surface of the core assembly, at least two adhesive assemblies 31 are provided along the outer circumferential surface of the core assembly, and adjacent adhesive assemblies 31 are spaced apart. Multiple adhesive assemblies 31 are spaced apart along the axial direction of the core assembly.

[0064] In some embodiments, such as Figure 3A and Figure 3B As shown, the orthographic projection of the adhesive portion 3 onto the surface of the electrode body 2 is circular or elliptical, with the diameter of the adhesive portion 3 ranging from 1.0 mm to 3.0 mm. Alternatively, the shape of the adhesive portion 3 can be set as a line, with the width of the adhesive portion 3 ranging from 1.0 mm to 3.0 mm, thereby allowing the adhesive portion 3 to balance bonding effect and buffer space.

[0065] Furthermore, when the diameter of the dot-shaped adhesive portion 3 is less than 1.0 mm, the adhesive force between the adhesive portion 3 and the battery casing 1 is too small, thus affecting the bonding effect. Conversely, when the diameter of the dot-shaped adhesive portion 3 is greater than 3.0 mm, under the condition of the same number of adhesive portions 3, the spacing between adjacent adhesive portions 3 will decrease, resulting in insufficient buffering effect provided by multiple adhesive portions 3, which is not conducive to fully absorbing the expansion force of the battery cell 100. As some examples, the diameter of the dot-shaped adhesive portion 3 can be 1.0 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.5 mm, 2.8 mm, 3.0 mm, or any value between any two of the above, or a range between any two of the above values.

[0066] When the width of the linear adhesive portion 3 is less than 1.0 mm, the bonding surface between the adhesive portion 3 and the battery casing 1 is small, resulting in a weaker bonding force and affecting the bonding effect. Conversely, when the width of the linear adhesive portion 3 is greater than 3.0 mm, the spacing between adjacent adhesive portions 3 decreases when the number of adhesive portions 3 is the same, leading to insufficient buffering effect from multiple adhesive portions 3 and hindering the absorption of the expansion force of the battery cell 100. As examples, the width of the linear adhesive portion 3 can be 1.0 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.5 mm, 2.8 mm, 3.0 mm, or any value between any two of these values, or a range between any two of these values.

[0067] Embodiments of this application also provide a method for assembling a battery cell, the method comprising: S1. Provide electrode body 2; S2. Apply adhesive to the surface of the electrode body 2 to form multiple bonding portions 3; wherein the adhesive suitable for making the bonding portions 3 has insulating properties, resistance to electrolyte corrosion, thermal conductivity, and elasticity. Suitable adhesive types include silicone, polyurethane, thermally conductive gel, and UV adhesive.

[0068] S3. Curing multiple adhesive portions 3 on the surface of the electrode body 2 after dispensing; wherein, a suitable curing method can be room temperature curing, heat curing or UV curing, depending on the type of adhesive used in the adhesive portions 3, so that the adhesive used in the adhesive portions 3 can be set.

[0069] S4. Place the cured electrode body 2 into the battery housing 1. The adhesive portion 3 forms a local protrusion structure on the surface of the electrode body 2, which plays a lubricating and guiding role in the process of pressing the electrode body into the battery housing 1. Moreover, the local friction between the multiple adhesive portions 3 and the battery housing 1 is much lower than the overall friction between the wrapped tape and the battery housing in related technologies, so that the process of placing the electrode body 2 into the battery housing 1 is smoother.

[0070] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0071] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0072] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0073] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. An electrode assembly (10), characterized in that, The electrode assembly (10) is adapted to be installed within the battery housing (1), and the electrode assembly (10) includes: Electrode body (2); Multiple adhesive portions (3) are spaced apart on the surface of the electrode body (2), and the adhesive portions (3) protrude relative to the surface of the electrode body (2).

2. The electrode assembly (10) according to claim 1, characterized in that, The electrode body (2) is configured as a core assembly, and the core assembly is provided with a plurality of adhesive portions (31) distributed at intervals along the circumferential or axial direction. The shape of the adhesive part (3) includes dots, and each adhesive part assembly (31) includes a plurality of adhesive parts (3) spaced apart. Alternatively, the shape of the adhesive portion (3) may include a linear shape, and each adhesive portion assembly (31) may include at least one adhesive portion (3).

3. The electrode assembly (10) according to claim 2, characterized in that, The core assembly is provided with a plurality of adhesive portion assemblies (31) distributed circumferentially, and the adhesive portion assemblies (31) extend in a straight line, a zigzag line, a sinusoidal line, or a spiral line in the axial direction of the core assembly.

4. The electrode assembly (10) according to claim 3, characterized in that, The adhesive assembly (31) extends at a height of h1 along the axial direction of the core assembly, and the height of the core assembly is h2; wherein 0.7≤h1 / h2≤0.

9.

5. The electrode assembly (10) according to claim 3, characterized in that, The electrode body (2) is provided with n bonding parts (31), where 4≤n≤12 and n is a positive integer.

6. The electrode assembly (10) according to claim 2, characterized in that, Each of the adhesive assembly (31) is configured to extend along a first direction, which is at an angle to the axial direction of the core assembly.

7. The electrode assembly (10) according to claim 6, characterized in that, The adhesive assembly (31) is configured to either close around the outer surface of the electrode body (2) or not close around the outer surface of the electrode body (2).

8. The electrode assembly (10) according to claim 6, characterized in that, The angle between the first direction and the axial direction of the core assembly is 30° - 70°.

9. The electrode assembly (10) according to any one of claims 1 to 8, characterized in that, The shape of the bonding part (3) on the axial cross-section of the electrode body (2) is circular or elliptical, and the diameter of the bonding part (3) is 1.0mm to 3.0mm. Alternatively, the shape of the adhesive portion (3) may include a linear shape, and the width of the adhesive portion (3) may range from 1.0 mm to 3.0 mm.

10. The electrode assembly (10) according to any one of claims 1 to 8, characterized in that, The adhesive part (3) is made of an elastic colloid, and the elastic compression range of the elastic colloid is 0.05mm ~ 0.5mm; And / or, the thermal conductivity of the adhesive part (3) is in the range of 0.2 W / (m·K) ~ 3.0 W / (m·K).

11. The electrode assembly (10) according to claim 10, characterized in that, The adhesive (3) is prepared from at least one of silicone, polyurethane adhesive, thermally conductive gel and UV adhesive.

12. The electrode assembly (10) according to any one of claims 1 to 8, characterized in that, The ratio of the total area of ​​the multiple adhesive portions (3) covering the outer surface of the electrode body (2) to the surface area of ​​the outer surface of the electrode body (2) is 0.05 to 0.

5.

13. The electrode assembly (10) according to any one of claims 1 to 8, characterized in that, The height of the adhesive part (3) protruding from the surface of the electrode body (2) is h, and the assembly interval between the electrode body (2) and the battery casing (1) is t, 0.5mm ≤ th ≤ 0.8mm.

14. The electrode assembly (10) according to claim 13, characterized in that, The multiple adhesive portions (3) protrude at the same height relative to the surface of the electrode body (2).

15. The electrode assembly (10) according to any one of claims 1 to 8, characterized in that, Multiple adhesive portions (3) are formed by dispensing adhesive onto the electrode body (2).

16. A battery cell (100), characterized in that, include: The electrode assembly (10) as described in any one of claims 1 to 15; Battery housing (1), the electrode assembly (10) is fixed inside the battery housing (1).

17. A method for assembling a battery cell (100), applicable to assembling the battery cell (100) of claim 16, characterized in that, The assembly method includes: Provide electrode body (2); Apply adhesive to the surface of the electrode body (2) to form multiple adhesive portions (3); The adhesive portions (3) on the surface of the electrode body (2) after dispensing are cured; The cured electrode body (2) is placed into the battery casing (1).

18. A battery pack, characterized in that, include: Multiple battery cells (100) as described in claim 16. The battery box is configured to accommodate multiple battery cells (100).

Images