Top cover assembly, battery, energy storage device and energy storage system

Abstract

The application discloses a top cover assembly applied to a battery, which comprises a cover plate, a lower insulating piece, a pole and a connecting piece. The lower insulating piece is arranged on one side of the cover plate, the pole penetrates the cover plate and the lower insulating piece and is welded to the connecting piece. A plurality of first boss portions are arranged on the lower insulating piece and face and abut the connecting piece, and an exhaust passage is formed between two adjacent first boss portions. The exhaust passage is communicated with the welding position of the pole and the connecting piece and the external environment, thereby providing an outward exhaust path for the high-temperature gas generated when the pole and the connecting piece are welded, effectively improving the welding explosion point problem caused by the failure of the high-temperature gas to be exhausted, and improving the welding quality and the electrical connection reliability of the top cover assembly. In addition, the application also discloses a battery, an energy storage device and an energy storage system comprising the top cover assembly.

Description

Technical Field

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

[0002] Rechargeable batteries, also known as secondary batteries or storage batteries, are batteries that can be recharged after discharge to reactivate the active materials and continue to be used. Their recyclable nature has made them a primary power source for electrical devices. As the demand for rechargeable batteries increases, higher requirements are being placed on their energy density, reliability, and cost. The top cover assembly, in particular, plays a crucial role in ensuring the safety of the battery cells.

[0003] However, existing top cover assemblies have limitations in actual welding processes. For example, when welding the pins to the terminals, the welding area is prone to quality defects such as weld spatter and uneven weld seams. This not only reduces the reliability of the conductive connection but also negatively impacts the long-term performance of the battery. Summary of the Invention

[0004] This application discloses a top cover assembly, a battery, an energy storage device, and an energy storage system, which can provide an external exhaust path for the high-temperature gas generated during the welding of the electrode post and the connecting piece while maintaining stable support of the connecting piece, thereby improving the welding quality of the top cover assembly and the reliability of the electrical connection.

[0005] To achieve the above objectives, in a first aspect, this application discloses a top cover assembly, the top cover assembly comprising: Cover plate; A lower insulating component is disposed on one side surface of the cover plate, and the lower insulating component is provided with a first pole post through hole; The electrode post is inserted through the cover plate and the first electrode post through hole; A connecting piece is located on the side of the lower insulating member away from the cover plate, and the connecting piece is welded to one end of the pole that passes through the hole of the first pole. The lower insulating member has a plurality of first protrusions that protrude toward and abut against the connecting piece. The plurality of first protrusions are arranged around the outer periphery of the first pole post through hole. An exhaust channel is formed between two adjacent first protrusions. The exhaust channel is configured to connect the connection between the pole post and the connecting piece and the external environment. The sum of the maximum arc lengths of the plurality of first protrusions along the circumference of the first pole post through hole is L1, and the sum of the maximum arc lengths of the plurality of exhaust channels along the circumference of the first pole post through hole is L2, satisfying: 0.7≤L1 / (L1+L2)≤0.95.

[0006] High-temperature gases are typically generated during welding of the pole and connecting piece. If these gases cannot be expelled in time, they can easily cause bursts at the weld, affecting the sealing performance and electrical connection reliability of the top cover assembly. This embodiment addresses this by providing multiple first protrusions on the lower insulating component, allowing these protrusions to support and abut against the connecting piece, with a gap between the surface of the lower insulating component and the connecting piece. The venting channel between adjacent first protrusions provides a path for the high-temperature gases generated during welding to escape, reducing the occurrence of weld bursts and improving the welding quality of the pole and connecting piece. Furthermore, to reasonably balance the support area of ​​the protrusions and the reserved space for the venting channel, this embodiment also limits the ratio of the total arc length L1 of the first protrusions to the total circumferential arc length (i.e., L1+L2) to between 0.7 and 0.95. This ensures stable support for the connecting piece while providing better ventilation space for the high-temperature gases. If the arc length ratio is too small (e.g., less than 0.7), it indicates that the arc length occupied by the first boss is too short, and the contact area between the first boss and the connecting piece is too small. This may easily lead to insufficient support from the first boss for the connecting piece, potentially causing the connecting piece to tilt under welding pressure. Conversely, if the arc length ratio is too large (e.g., greater than 0.95), the arc length occupied by the exhaust channel is too narrow. In this case, high-temperature gas is prone to converge at the weld due to poor exhaust, which may result in welding bursts at the weld, affecting the welding quality.

[0007] As an optional implementation, the lower insulating member has a first surface facing the connecting piece and a second surface opposite to the first surface, the first pole post through hole passing through the first surface and the second surface, and a plurality of first boss portions provided on the first surface; The first surface is also provided with an exhaust groove located between the first pole post through hole and the plurality of first protrusion portions, and the exhaust groove is connected to the exhaust channel and the first pole post through hole.

[0008] The welding position of the electrode post and the connecting piece is usually close to the perforation of the first electrode post. Therefore, the high-temperature gas generated during welding will first accumulate near the perforation of the first electrode post. If the gas cannot diffuse outward quickly, it is easy to cause high-temperature bubbles or bursts at the weld between the electrode post and the connecting piece. By providing an exhaust groove on the first surface of the lower insulating member, and positioning the exhaust groove between the first electrode post perforation and multiple first protrusions, the exhaust groove can form a space inside the first protrusion. The high-temperature gas generated during welding will preferentially enter the exhaust groove after overflowing. Since the exhaust groove is connected to both the first electrode post perforation and the exhaust channel, the exhaust groove can guide the accumulated gas to the exhaust channel between adjacent first protrusions. This guiding effect helps to accelerate the gas discharge speed and avoid a large amount of gas accumulating at the weld gap between the electrode post and the connecting piece, thereby improving the welding quality of the electrode post and the connecting piece.

[0009] As an optional implementation, the first boss portion and the first pole post through hole are connected by an inclined surface, the inclined surface being inclined from the outer periphery of the first pole post through hole toward the first boss portion, so that the first boss portion and the first pole post through hole form the vent groove that widens along the thickness direction of the cover plate, and the inclined surface is configured as the inner wall surface of the vent groove.

[0010] By providing an inclined surface between the first boss and the first pole post perforation, and by tilting the inclined surface from the outer periphery of the first pole post perforation towards the first boss, the exhaust groove gradually widens along the thickness of the cover plate. This widening shape conforms to the flow trend of gas expanding when heated and diffusing outwards. When gas overflows from the weld and enters the exhaust groove, the inclined surface guides the airflow. Therefore, the widened exhaust groove helps to accelerate the flow of accumulated gas into the exhaust channel, thereby reducing the bursting phenomenon at the weld between the pole post and the connecting piece and improving the weld quality.

[0011] As an optional implementation, the welding joint between the connecting piece and the pole post forms an annular welding trajectory with a radius of R1. The radius of the first protrusion portion near the inner edge of the first pole post through hole is R2, and the radius of the first protrusion portion away from the outer edge of the first pole post through hole is R3, wherein R2 < R3. Satisfying: 4mm ≤ R2 - R1 ≤ 15mm; and / or, The following condition must be met: 4mm≤R3-R1≤15mm.

[0012] If the first boss is too close to the weld, heat can easily be transferred to the first boss and damage the lower insulating component, which can lead to tilting of the connecting piece and volatilization of the insulating material. Therefore, this embodiment limits the differences R2-R1 and R3-R1 to between 4mm and 15mm, which helps the first boss provide support at a safe distance. If the difference R2-R1 or R3-R1 is too small (e.g., less than 4mm), it means that the edge of the first boss is too close to the weld, which can easily cause the first boss to melt due to heat and generate volatile gases. If the difference R2-R1 or R3-R1 is too large (e.g., greater than 15mm), it means that the edge of the first boss is too far from the weld, which can easily reduce the support effect of the first boss on the welding area of ​​the connecting piece. Therefore, by controlling the distance from the inner and outer edges of the first boss to the weld to between 4mm and 15mm, it is beneficial to maintain the stable posture of the connecting piece during the welding process while avoiding the lower insulating component from melting due to high temperature.

[0013] As an optional implementation, the welding joint between the connecting piece and the pole post forms an annular welding trajectory with a radius of R1. The radius of the first protrusion portion near the inner edge of the first pole post through hole is R2, and the radius of the first protrusion portion away from the outer edge of the first pole post through hole is R3, wherein R2 < R3. Satisfying: 4mm ≤ R2 - R1 ≤ 15mm; and / or, Satisfying: 4mm ≤ R3 - R1 ≤ 15mm; and / or, Satisfies: 1mm≤R3-R2.

[0014] The difference R3-R2 represents the solid width of the first boss portion along the radial direction of the pole post. If the difference R3-R2 is too small (e.g., less than 1mm), it indicates that the top support surface of the first boss portion is too narrow, which can easily lead to excessive pressure when the first boss portion contacts the connecting piece, and thus easily deform under assembly pressure, making it difficult to provide stable support for the connecting piece. Therefore, by limiting 1mm≤R3-R2, it is beneficial to ensure that the first boss portion has sufficient contact area, thereby stably supporting the connecting piece. In addition, combining the safety distance limits of 4mm≤R2-R1≤15mm and 4mm≤R3-R1≤15mm with the support width limit (i.e., 1mm≤R3-R2) allows the first boss portion to play its due support role without melting at high temperatures, which is beneficial to improving the versatility of the lower insulation component structure design.

[0015] As an optional implementation, the number of the first boss portions is at least three, arranged at equal intervals along the circumference of the first pole post perforation; and / or, The sum of the maximum arc lengths of the multiple first boss portions along the circumferential direction of the first pole post perforation is L1, which satisfies: 30mm≤L1≤80mm.

[0016] When the pole post and the connecting piece are welded together, the connecting piece needs to withstand downward compressive force and the pressure from the welding operation. By providing at least three first protrusions and arranging them at equal intervals along the circumference of the perforation of the first pole post, a multi-point support structure can be formed on the outer periphery of the perforation of the first pole post, which helps to ensure that the connecting piece is subjected to uniform force when under pressure.

[0017] The sum of the maximum arc lengths of the first boss portion, L1, determines the total support area of ​​the first boss portion on the connecting piece. If the total arc length L1 is too small (e.g., less than 30mm), it indicates that the overall size of the first boss portion is too small, and the support area between the first boss portion and the connecting piece is insufficient. In this case, the connecting piece is prone to deformation under downward pressure. If the total arc length L1 is too large (e.g., greater than 80mm), it indicates that the first boss portion occupies too much space around the perforation of the first pole post. This will directly compress the space of the exhaust channel, causing the exhaust channel between adjacent first boss portions to become narrow, which can easily lead to welding bursts. Therefore, this application also controls the sum of the maximum arc lengths L1 between 30mm and 80mm, which is beneficial to ensure that the connecting piece obtains sufficient and stable support strength while also reserving sufficient exhaust space for gas.

[0018] As an optional implementation, the pole includes a pole body and a first protrusion. The first protrusion protrudes from the outer peripheral surface of the pole body in the radial direction of the pole. The pole body and the first protrusion pass through the first pole through hole, so that the first protrusion is located between the lower insulating member and the connecting piece in the thickness direction of the cover plate. The top cover assembly also includes a sealing ring, which includes a sealing body and a second protrusion disposed on the sealing body. The sealing body is sleeved on the outer periphery of the pole body and is pressed between the cover plate and the pole body along the thickness direction of the cover plate. The second protrusion protrudes along the outer periphery of the sealing body and is pressed between the lower insulating member and the first protrusion along the thickness direction of the cover plate. The orthographic projection of the lower insulating member along the thickness direction of the cover plate at least partially overlaps with the projection of the second protrusion along the thickness direction of the cover plate, and the overlapping part has a dimension W in the radial direction of the pole post, satisfying: W≥0.1mm.

[0019] By aligning the projection of the lower insulator in the thickness direction of the cover plate with the projection of the second protrusion of the sealing ring, an overlapping blocking structure can be formed at the junction of the lower insulator and the second protrusion. This overlapping structure blocks the channel for electrolyte penetration, which helps to avoid the risk of leakage or short circuit between the terminal and the external structure. Furthermore, the radial dimension of the overlapping portion of the terminal must be greater than or equal to 0.1 mm. If the overlapping dimension W is too small (e.g., less than 0.1 mm), it indicates that the overlapping area between the lower insulator and the second protrusion is too narrow, and misalignment between the lower insulator and the second protrusion can easily occur, re-exposing gaps and causing the insulation to fail in its anti-leakage function. Therefore, limiting the size W of the overlapping portion to greater than or equal to 0.1 mm helps maintain the stability of the sealing ring structure, avoids or reduces the phenomenon of electrolyte seeping into the top cover, and thus improves the safety performance of the battery.

[0020] As an optional implementation, the connecting piece is provided with a second electrode through hole for the electrode post to pass through. Along the radial direction of the electrode post, there is a gap X between the inner wall surface of the second electrode through hole and the outer circumferential surface of the electrode post, satisfying: 0.05mm ≤ X ≤ 3mm; and / or, The connecting piece has a third surface opposite to the lower insulator and a fourth surface opposite to the third surface. The fourth surface has a second pole hole that extends through the third surface and is used for the pole to pass through. The third surface has a groove located on the outer periphery of the second pole hole. Along the thickness direction of the cover plate, the end face of the pole that passes through the second pole hole is located in the groove and does not protrude from the third surface of the connecting piece.

[0021] The electrode post needs to pass through the hole in the connecting piece for subsequent welding and fixing. A gap X is provided between the inner wall of the second electrode post's perforation and the outer circumference of the electrode post to facilitate smooth insertion into the connecting piece. Based on this, this embodiment limits the value of the gap X to between 0.05mm and 3mm. This balances the convenience of electrode post insertion and assembly with the reliability of welding between the electrode post and the connecting piece. If the gap X is too small (e.g., less than 0.05mm), the fit between the second electrode post's perforation and the electrode post is too tight. When faced with machining errors or thermal expansion and contraction caused by temperature changes, the electrode post may easily get stuck at the edge of the second electrode post's perforation, affecting the assembly effect. If the gap X is too large (e.g., greater than 3mm), the gap between the electrode post and the connecting piece is too wide. During welding operations, this can easily lead to incomplete or missed welds, thereby reducing the structural connection strength and conductivity between the electrode post and the connecting piece.

[0022] Secondly, this application also discloses a battery that includes a top cover assembly as described in the first aspect.

[0023] The battery features the aforementioned top cover assembly. Therefore, by providing multiple first protrusions on the lower insulating member to support the connecting piece, and leaving venting channels between adjacent first protrusions, high-temperature gases generated during welding can be discharged, thereby reducing the risk of bursting at the weld between the terminal and the connecting piece. Simultaneously, by controlling the distance from the first protrusion to the terminal weld and by providing overlapping structures between the lower insulating member and the sealing ring, channels for electrolyte to seep into the top cover can be blocked, improving insulation safety performance. Thus, the top cover assembly of this application improves the welding quality between the terminal and the connecting piece while also enhancing the sealing and insulation performance of the structure, contributing to improved overall structural stability and safety performance of the battery.

[0024] Thirdly, this application also discloses an energy storage device, which includes a battery as described in the second aspect.

[0025] Fourthly, this application also discloses an energy storage system, which includes the energy storage device as described in the third aspect.

[0026] This application provides a top cover assembly, a battery, an energy storage device, and an energy storage system. The top cover assembly, by providing multiple first protrusions on the lower insulating member that protrude towards and abut against the connecting piece, creates a gap between the lower insulating member and the connecting piece, and forms an exhaust channel connecting to the outside between adjacent first protrusions. This support structure with exhaust channels provides a smooth outward exhaust path for the high-temperature gases generated during welding of the electrode and the connecting piece, thereby improving issues such as welding bursts. Simultaneously, through a reasonable proportion design, while ensuring that the first protrusions have sufficient contact area to support the connecting piece and prevent it from being burned and deformed under assembly and welding pressure, it also reserves ample exhaust space for high-temperature gases, preventing gas from accumulating at the weld due to poor exhaust. Therefore, the top cover assembly of this application, while maintaining stable support for internal components, effectively improves the welding quality of the electrode and the connecting piece, thus contributing to improved safety and stability of the top cover assembly, battery, energy storage device, and energy storage system. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in 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.

[0028] Figure 1 This is a schematic diagram of the structure of the top cover assembly disclosed in the embodiments of this application; Figure 2 yes Figure 1 A cross-sectional view of the top cover assembly in the AA direction; Figure 3 yes Figure 2 Enlarged schematic diagram of point I in the middle; Figure 4 yes Figure 3 Enlarged schematic diagram at point II; Figure 5 This is an exploded view of the top cover assembly disclosed in the embodiments of this application; Figure 6 This is a schematic diagram of the structure of the insulating component from one perspective disclosed in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of the insulating component from another perspective disclosed in the embodiments of this application; Figure 8 This is a schematic diagram of the battery disclosed in the embodiments of this application; Figure 9 This is a schematic diagram of the energy storage device disclosed in the embodiments of this application; Figure 10 This is a schematic diagram of the energy storage system disclosed in the embodiments of this application.

[0029] Explanation of reference numerals in the attached figures: Top cover assembly - 100; Battery - 200; Energy storage device - 300; Energy storage system - 400; Cover plate -10; Lower insulating component-20; First pole post perforation-21; First boss portion-22; Exhaust channel-23; First surface-24; Second surface-25; Exhaust groove-26; Inclined surface-27; pole post-30; pole post body-31; first protrusion-32; Connecting piece -40; Second pole post perforation -41; Third surface -42; Fourth surface -43; Groove -44; Sealing ring - 50; Sealing body - 51; Second protrusion - 52; The sum of the maximum arc lengths of the multiple first boss portions along the circumferential direction of the first pole post perforation - L1; the sum of the maximum arc lengths of the multiple exhaust channels along the circumferential direction of the first pole post perforation - L2; the radius of the annular welding trajectory - R1; the radius of the first boss portion near the inner edge of the first pole post perforation - R2; the radius of the first boss portion away from the outer edge of the first pole post perforation - R3; the dimension of the overlapping portion in the radial direction of the pole post - W; the radius of the sealing body portion near the inner edge of the pole post body - R4; the radius of the outer circumferential surface of the pole post body - R5. 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 some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In this application, the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0032] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0033] Furthermore, the terms "installation," "setting," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0034] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0035] As described in the background section of this application, the welding of the terminals and internal connecting pieces (or pins) of the top cover assembly is a crucial step in the manufacturing process of secondary batteries. However, existing top cover assemblies have limitations in actual welding processes. For example, when welding the pins to the terminals, quality defects such as weld spatter and uneven weld seams often occur at the welding points. This not only reduces the reliability of the conductive connection but also negatively impacts the long-term performance of the battery.

[0036] Based on this, this application discloses a top cover assembly, a battery, an energy storage device, and an energy storage system, which features multiple raised first bosses on the side of the lower insulating component facing the connecting piece. This boss structure supports the connecting piece upwards during assembly and simultaneously forms an exhaust channel between adjacent bosses, creating an outward pathway for the high-temperature gases generated during welding. This support structure with exhaust channels effectively reduces welding bursts while preventing the lower insulating component from being damaged by high temperatures, thus improving the yield rate of electrode welding and the overall stability of the top cover assembly.

[0037] The following will provide a detailed description of the top cover assembly, battery, energy storage device, and energy storage system of this application, with reference to the accompanying drawings.

[0038] Please see Figures 1 to 6 , Figure 1 This is a schematic diagram of the top cover assembly disclosed in an embodiment of this application. Figure 2 yes Figure 1 A cross-sectional view of the top cover assembly in the AA direction. Figure 3 yes Figure 2 Enlarged diagram of point I in the middle. Figure 4 yes Figure 3 Enlarged schematic diagram at point II in the middle. Figure 5 This is an exploded view of the top cover assembly disclosed in an embodiment of this application. Figure 6 This is a schematic diagram of the structure of the insulating component from one perspective of the embodiments disclosed in this application.

[0039] It should be noted that, in order to clearly show the internal details, Figure 2 , Figure 5 and Figure 6 Only a portion of the component's structure is shown, with breaks marked by wavy lines. Similar situations are shown in the accompanying figures below, and will not be repeated here.

[0040] This application discloses a top cover assembly 100. The top cover assembly 100 includes a cover plate 10, a lower insulating member 20, a pole post 30, and a connecting piece 40. The lower insulating member 20 is disposed on one side surface of the cover plate 10 and has a first pole post through hole 21. The pole post 30 passes through the cover plate 10 and the first pole post through hole 21. The connecting piece 40 is located on the side of the lower insulating member 20 away from the cover plate 10, and the connecting piece 40 is welded to one end of the pole post 30 that passes through the first pole post through hole 21. The lower insulating member 20 has a plurality of first protrusions 22 that protrude toward and abut against the connecting piece 40. The plurality of first protrusions 22 are arranged around the outer periphery of the first pole post through hole 21, and an exhaust channel 23 is formed between two adjacent first protrusions 22. The exhaust channel 23 connects the connection between the pole post 30 and the connecting piece 40 and the external environment.

[0041] Specifically, high-temperature gases are typically generated during the welding of the pole post 30 and the connecting piece 40. If these gases cannot be expelled in time, they can easily cause bursts at the weld, affecting the sealing performance and electrical connection reliability of the top cover assembly 100. This embodiment addresses this by providing multiple first protrusions 22 on the lower insulating member 20, allowing each protrusion 22 to support and abut against the connecting piece 40, with a gap between the surface of the lower insulating member 20 and the connecting piece 40. The venting channels 23 between adjacent first protrusions 22 provide a path for the high-temperature gases generated during welding to escape, reducing the occurrence of weld bursts and improving the welding quality of the pole post 30 and the connecting piece 40.

[0042] In some embodiments, the plurality of first protrusions are arranged around the first pole post through hole. Since the first pole post through hole is a round hole, the first protrusion is also formed as an arc-shaped protrusion in the circumferential direction of the first pole post through hole. Therefore, the exhaust groove formed between two adjacent first protrusions is also an arc-shaped groove.

[0043] In some embodiments, the sum of the maximum arc lengths of the plurality of first protrusions 22 along the circumference of the first pole post through hole 21 is L1, and the sum of the maximum arc lengths of the plurality of exhaust channels 23 along the circumference of the first pole post through hole 21 is L2, satisfying: 0.7≤L1 / (L1+L2)≤0.95. It is understood that the specific value of the arc length ratio L1 / (L1+L2) can be 0.7, 0.75, 0.8, 0.85, 0.9, or 0.95, etc., and this embodiment does not impose a specific numerical limitation on it.

[0044] This embodiment also limits the ratio of the total arc length L1 of the first boss portion 22 to the total circumferential arc length (i.e., L1+L2) to be between 0.7 and 0.95. If the arc length ratio is too small (e.g., less than 0.7), it indicates that the arc length occupied by the first boss portion 22 is short, and the contact area between the first boss portion 22 and the connecting piece 40 is too small, which may easily lead to insufficient support of the first boss portion 22 for the connecting piece 40, and may cause the connecting piece 40 to tilt under welding pressure. If the arc length ratio is too large (e.g., greater than 0.95), the arc length occupied by the exhaust channel 23 is too narrow, and high-temperature gas is prone to converge at the weld due to poor exhaust. Therefore, by controlling the arc length ratio L1 / (L1+L2) between 0.7 and 0.95, it is beneficial to maintain the stable support of the first boss portion 22 for the connecting piece 40 while providing better drainage space for the exhaust of high-temperature gas.

[0045] It is understood that the shape of the cover plate 10 can be adapted to the shape of the battery casing. For example, the cover plate 10 can be rectangular, circular, etc. This embodiment does not make specific limitations in this regard.

[0046] It is understood that the lower insulating member 20 is mainly used to achieve electrical isolation between the cover plate 10 and the live parts. The material of the lower insulating member 20 may include polymer materials with insulating properties such as polypropylene, polybutylene terephthalate or polyphenylene sulfide. This embodiment does not specifically limit this.

[0047] It is understood that the connecting piece 40 can be a conductive component such as a current collector, a tab, a pin, or an electrical connection block. The specific form and name of the connecting piece 40 can be adapted to the electrode structure of the battery cell. For example, in some embodiments, the connecting piece 40 can be directly welded to the tab of the battery cell, or it can be connected to the tab as part of the current collector; this embodiment does not specifically limit this.

[0048] It is understood that the arrangement of the multiple first protrusions 22 along the circumference of the first pole post through hole 21 can be either equally spaced or unequally spaced, as long as an exhaust channel 23 can be formed between adjacent first protrusions 22. This embodiment does not make specific limitations in this regard.

[0049] In some embodiments, such as Figures 2 to 4 As shown, the lower insulating member 20 has a first surface 24 facing the connecting piece 40 and a second surface 25 opposite to the first surface 24. A first pole post through hole 21 passes through the first surface 24 and the second surface 25. A plurality of first protrusions 22 are provided on the first surface 24. The first surface 24 is also provided with an exhaust groove 26 located between the first pole post through hole 21 and the plurality of first protrusions 22. The exhaust groove 26 communicates with the exhaust channel 23 and the first pole post through hole 21.

[0050] Specifically, the welding position of the electrode post 30 and the connecting piece 40 is usually close to the first electrode post through hole 21. Therefore, the high-temperature gas generated during welding will first accumulate near the first electrode post through hole 21. If the gas cannot diffuse outward quickly, it is easy to cause high-temperature bubbles or bursts at the welding point of the electrode post 30 and the connecting piece 40. By providing an exhaust groove 26 on the first surface 24 of the lower insulating member 20, and positioning the exhaust groove 26 between the first electrode post through hole 21 and the plurality of first protrusions 22, the exhaust groove 26 can form a space inside the first protrusions 22. The high-temperature gas generated during welding will preferentially enter the exhaust groove 26 after overflowing. Since the exhaust groove 26 is connected to both the first electrode post through hole 21 and the exhaust channel 23, the exhaust groove 26 can guide the accumulated gas into the exhaust channel 23 between adjacent first protrusions 22. This guiding effect helps to accelerate the gas discharge speed and avoid a large amount of gas accumulating at the welding gap between the electrode post 30 and the connecting piece 40, thereby improving the welding quality of the electrode post 30 and the connecting piece 40.

[0051] It is understood that the cross-sectional shape of the exhaust groove 26 can be adapted to the actual needs of gas flow. For example, the cross-section of the exhaust groove 26 can be rectangular, etc. This embodiment does not make specific limitations on this.

[0052] In some embodiments, such as Figures 2 to 4 As shown, the first boss portion 22 and the first pole post through hole 21 are connected by an inclined surface 27. The inclined surface 27 is inclined from the outer periphery of the first pole post through hole 21 toward the first boss portion 22, so that an venting groove 26 with an flared opening along the thickness direction of the cover plate 10 is formed between the first boss portion 22 and the first pole post through hole 21. The inclined surface 27 is constructed as the inner wall surface of the venting groove 26.

[0053] Specifically, by providing an inclined surface 27 between the first protrusion 22 and the first pole post through hole 21, and by making the inclined surface 27 inclined from the outer periphery of the first pole post through hole 21 toward the first protrusion 22, the exhaust groove 26 exhibits a gradually widening shape along the thickness direction of the cover plate 10. This widening shape conforms to the flow trend of gas expanding when heated and diffusing outwards. When gas overflows from the weld and enters the exhaust groove 26, the inclined surface 27 can guide the airflow. It can be seen that the widened exhaust groove 26 helps to accelerate the flow of accumulated gas into the exhaust channel 23, thereby helping to reduce the bursting phenomenon at the weld between the pole post 30 and the connecting piece 40 and improve the welding quality of the weld.

[0054] It is understood that the tilt angle formed by the inclined surface 27 relative to the axis of the first pole post through hole 21 can be adapted to the depth of the exhaust groove 26 and the thickness of the lower insulating member 20. For example, the tilt angle can be 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, etc. This embodiment does not make specific numerical limitations on this.

[0055] In some embodiments, such as Figure 5 and Figure 7 As shown, Figure 7 This is a schematic diagram of the lower insulating member from another perspective of the embodiments disclosed in this application. The number of first boss portions 22 is at least three, which are arranged at equal intervals along the circumference of the first pole post through hole 21.

[0056] Specifically, when the pole post 30 and the connecting piece 40 are welded together, the connecting piece 40 needs to withstand downward compressive force and the pressure from the welding operation. By providing at least three first protrusions 22 and arranging these first protrusions 22 at equal intervals along the circumference of the first pole post through hole 21, a multi-point support structure can be formed on the outer periphery of the first pole post through hole 21, which helps to ensure that the connecting piece 40 is subjected to uniform force when under pressure.

[0057] It is understood that the specific number of the first protrusion 22 can be selected in combination with the actual size and requirements of the first pole post through hole 21. For example, the number of the first protrusion 22 can be 3, 4, 5, 6, 7, 8, etc. This embodiment does not make a specific number limit.

[0058] In some embodiments, the sum of the maximum arc lengths of the plurality of first boss portions 22 along the circumferential direction of the first pole post through hole 21 is L1, satisfying: 30mm≤L1≤80mm.

[0059] Specifically, the sum of the maximum arc lengths L1 of the first boss portion 22 determines the total support area of ​​the first boss portion 22 on the connecting piece 40. If the total arc length L1 is too small (e.g., less than 30 mm), it means that the overall size of the first boss portion 22 is too small, and the support area of ​​the first boss portion 22 in contact with the connecting piece 40 is insufficient. In this case, the connecting piece 40 is prone to deformation under downward pressure. If the total arc length L1 is too large (e.g., greater than 80 mm), it means that the first boss portion 22 occupies too much space around the outer periphery of the first pole post through hole 21. This will directly compress the space of the exhaust channel 23, causing the exhaust channel 23 between adjacent first boss portions 22 to become narrow, which will easily lead to welding bursts. Therefore, this application also controls the sum of the maximum arc lengths L1 between 30 mm and 80 mm, which is beneficial to ensure that the connecting piece 40 obtains sufficient and stable support strength while also reserving sufficient exhaust space for gas.

[0060] It is understood that the specific value of the sum of the maximum arc lengths L1 can be 30mm, 32mm, 35mm, 38mm, 40mm, 42mm, 45mm, 48mm, 50mm, 52mm, 55mm, 58mm, 60mm, 62mm, 65mm, 68mm, 70mm, 72mm, 75mm, 78mm, 80mm, etc. This embodiment does not impose a specific numerical limitation on this.

[0061] In some embodiments, such as Figure 3 , Figure 4 As shown, the welding joint between the connecting piece 40 and the pole post 30 forms an annular welding trajectory with a radius of R1. The radius of the inner edge of the first protrusion 22 near the first pole post through hole 21 is R2, and the radius of the outer edge of the first protrusion 22 away from the first pole post through hole 21 is R3, where R2 < R3. The following conditions must be met: 4mm ≤ R2 - R1 ≤ 15mm; and / or, 4mm ≤ R3 - R1 ≤ 15mm.

[0062] Specifically, if the first protrusion 22 is too close to the weld, heat can easily be transferred to the first protrusion 22, causing damage to the lower insulating component 20, which in turn can easily lead to tilting of the connecting piece 40 and volatilization of the insulating material. Therefore, this embodiment limits the differences R2-R1 and R3-R1 to between 4mm and 15mm, which helps the first protrusion 22 provide support at a safe distance. If the difference R2-R1 or R3-R1 is too small (e.g., less than 4mm), it means that the edge of the first protrusion 22 is too close to the weld, which can easily cause the first protrusion 22 to melt due to heat and generate volatile gases. If the difference R2-R1 or R3-R1 is too large (e.g., greater than 15mm), it means that the edge of the first protrusion 22 is too far from the weld, which can easily lead to a decrease in the support effect of the first protrusion 22 on the welding area of ​​the connecting piece 40. Therefore, by controlling the distance from the inner and outer edges of the first boss portion 22 to the welding point to between 4mm and 15mm, it is beneficial to maintain the stable posture of the connecting piece 40 during the welding process while avoiding the lower insulating part 20 from melting at high temperature.

[0063] It is understandable that R2-R1 < R3-R1. In order to ensure that the first protrusion 22 can form the exhaust channel 23 and provide support, the radius of the outer edge of the first protrusion 22 away from the first pole post through hole 21 must be greater than the radius of the inner edge of the first protrusion 22 near the first pole post through hole 21.

[0064] It is understood that the specific value of the difference R2-R1 can be 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, etc., and this embodiment does not impose a specific numerical limitation on it.

[0065] It is understood that the specific values ​​of the difference R3-R1 may include, but are not limited to, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, etc. This embodiment does not impose specific numerical limitations on this.

[0066] It is understood that the annular welding trajectory can be a continuous closed circular trajectory formed by the laser welding equipment rotating around the center of the pole post 30, or it can be an approximately annular trajectory formed by splicing multiple arc-shaped welds or multiple spot welds. As long as the pole post 30 and the connecting piece 40 can be fixed, this embodiment does not make specific limitations on this.

[0067] In some embodiments, such as Figure 2 and Figure 3As shown, the welding joint between the connecting piece 40 and the pole post 30 forms an annular welding trajectory with a radius of R1. The radius of the inner edge of the first protrusion 22 near the first pole post through hole 21 is R2, and the radius of the outer edge of the first protrusion 22 away from the first pole post through hole 21 is R3, where R2 < R3. The following conditions must be met: 4mm ≤ R2 - R1 ≤ 15mm; and / or 4mm ≤ R3 - R1 ≤ 15mm; and / or 1mm ≤ R3 - R2.

[0068] Specifically, the difference R3-R2 represents the solid width of the first boss portion 22 along the radial direction of the pole post 30. If the difference R3-R2 is too small (e.g., less than 1 mm), it indicates that the top support surface of the first boss portion 22 is too narrow, which can easily lead to excessive pressure when the first boss portion 22 contacts the connecting piece 40, and thus easily deform under assembly pressure, making it difficult to stably support the connecting piece 40. Therefore, by limiting 1 mm ≤ R3-R2, it is beneficial to ensure that the first boss portion 22 has sufficient contact area, thereby stably supporting the connecting piece 40. In addition, combining the safety distance limits of 4 mm ≤ R2-R1 ≤ 15 mm and 4 mm ≤ R3-R1 ≤ 15 mm with the support width limit (i.e., 1 mm ≤ R3-R2) allows the first boss portion 22 to play its due supporting role without melting at high temperatures, which is beneficial to improving the versatility of the structural design of the lower insulating component 20.

[0069] It is understood that the specific values ​​of the difference R3-R2 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc., and this embodiment does not impose specific numerical limitations on them.

[0070] In some embodiments, such as Figure 4 and Figure 5 As shown, the connecting piece 40 is provided with a second pole post through hole 41 for the pole post 30 to pass through. Along the radial direction of the pole post 30, there is a gap X between the inner wall surface of the second pole post through hole 41 and the outer peripheral surface of the pole post 30, which satisfies: 0.05mm≤X≤3mm.

[0071] Specifically, the electrode post 30 needs to pass through the hole in the connecting piece 40 for subsequent welding and fixing. A gap X is reserved between the inner wall of the second electrode post through hole 41 and the outer peripheral surface of the electrode post 30, facilitating the smooth insertion of the electrode post 30 into the connecting piece 40. Based on this, this embodiment limits the value of the gap X to between 0.05mm and 3mm. This balances the convenience of electrode post insertion and assembly with the reliability of welding between the electrode post and the connecting piece. If the gap X is too small (e.g., less than 0.05mm), the fit between the second electrode post through hole 41 and the electrode post 30 is too tight. When faced with machining errors or thermal expansion and contraction caused by temperature changes, the electrode post 30 may easily get stuck at the edge of the second electrode post through hole 41, affecting the assembly effect. If the gap X is too large (e.g., greater than 3mm), the gap between the electrode post 30 and the connecting piece 40 is too wide. During welding operations, incomplete or missed welds are likely to occur, thereby reducing the structural connection strength and conductivity between the electrode post 30 and the connecting piece 40.

[0072] It is understood that the specific value of the gap X can be 0.05mm, 0.08mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.5mm, 1.8mm, 2.0mm, 2.2mm, 2.5mm, 2.8mm, 3.0mm, etc., and this embodiment does not impose a specific numerical limit on it.

[0073] In some embodiments, such as Figures 3 to 5 As shown, the connecting piece 40 has a third surface 42 facing away from the lower insulating member 20 and a fourth surface 43 facing away from the third surface 42. The fourth surface 43 is provided with a second pole hole 41 that extends through the third surface 42 and is used for the pole 30 to pass through. The third surface 42 is provided with a groove 44. The groove 44 is located on the outer periphery of the second pole hole 41. Along the thickness direction of the cover plate 10, the end face of the pole 30 that passes through the second pole hole 41 is located in the groove 44 and does not protrude from the third surface 42 of the connecting piece 40.

[0074] Specifically, after the pole post 30 passes through the connecting piece 40, the end face of the pole post 30 needs to be welded and fixed to the connecting piece 40. If there is a certain height difference between the end of the pole post 30 and the welding surface of the connecting piece 40 (for example, the pole post 30 protrudes from the connecting piece 40 or is recessed inside the connecting piece 40), it is easy to cause uneven heating during welding, which can easily lead to problems such as incomplete welding or insufficient welding strength. However, by providing a groove 44 on the third surface 42 of the connecting piece 40, and making the bottom wall surface of the groove 44 flush with the end face of the pole post 30 that exits the second pole post through hole 41, the pole post 30 and the connecting piece 40 form a roughly flat plane in the main welding area. This facilitates uniform heating of the pole post 30 and the connecting piece 40 by the welding equipment, thereby improving the welding quality between the pole post 30 and the connecting piece 40, and thus improving the stability of the internal electrical connection and the structural connection strength of the top cover assembly 100.

[0075] It is understandable that dimensional tolerances often exist in the processing and assembly of parts during industrial production and assembly. In this embodiment, one end face of the pole post 30 is located within the groove 44 and does not protrude from the third surface 42, which means that the end face of the pole post 30 can be flush with the bottom wall surface of the groove 44, or slightly higher or slightly lower than the bottom wall surface of the groove 44.

[0076] It is understood that the bottom wall surface of the groove portion 44 in this application is approximately flush with the end face of the pole post 30 that passes through the second pole post through hole 41. Slight height differences due to machining or assembly tolerances are permissible, as long as the two can form a flat surface that is conducive to welding.

[0077] It is understood that the cross-sectional profile of the groove 44 can be circular, rectangular, polygonal, elliptical, etc., and this embodiment does not specifically limit it.

[0078] In some embodiments, such as Figures 2 to 6 As shown, the electrode post 30 includes an electrode post body 31 and a first protrusion 32. The first protrusion 32 protrudes from the outer peripheral surface of the electrode post body 31 along the radial direction of the electrode post 30. The electrode post body 31 and the first protrusion 32 pass through the first electrode post through hole 21, so that the first protrusion 32 is located between the lower insulating member 20 and the connecting piece 40 along the thickness direction of the cover plate 10. The top cover assembly 100 also includes a sealing ring 50, which includes a sealing body 51 and a second protrusion 52 disposed on the sealing body 51. The sealing body 51 is sleeved on the outer periphery of the electrode post body 31, and the sealing body 51 is pressed between the cover plate 10 and the electrode post body 31 along the thickness direction of the cover plate 10. The second protrusion 52 protrudes from the outer periphery of the sealing body 51, and the second protrusion 52 is pressed between the lower insulating member 20 and the first protrusion 32 along the thickness direction of the cover plate 10.

[0079] Specifically, the battery typically contains electrolyte, and there is an assembly gap between the terminal post 30 and the surrounding structure. By aligning the projection of the lower insulating member 20 in the thickness direction of the cover plate 10 with the projection of the second protrusion 52 of the sealing ring 50, an overlapping barrier structure can be formed at the junction of the lower insulating member 20 and the second protrusion 52. This overlapping structure blocks the channel for electrolyte penetration, which helps to avoid the risk of leakage or short circuit between the terminal post 30 and the external structure.

[0080] It is understood that the material of the sealing ring 50 may include, but is not limited to, silicone rubber, fluororubber, EPDM rubber or polyurethane rubber, etc., and this embodiment does not make specific limitations on this.

[0081] It is understood that the overall cross-sectional shape formed by the sealing body 51 and the second protrusion 52 can be designed according to the specific shape of the sealing space. For example, the cross-section of the sealing ring 50 can be L-shaped, T-shaped or stepped, as long as the second protrusion 52 can be pressed between the lower insulating member 20 and the first protrusion 32. This embodiment does not make specific limitations on this.

[0082] It is understandable that the electrode body can be a single structure or a multi-part assembly structure with separate components. When the electrode body is a separate structure, for example, it may include an upper electrode section and a lower electrode section, which can be electrically connected by means of laser welding, ultrasonic welding, riveting, or threaded connection. For example, in this separate structure, the first protrusion can be a flange integrally formed on the outer circumference of the lower electrode section.

[0083] In some embodiments, the orthographic projection of the lower insulating member 20 along the thickness direction of the cover plate 10 at least partially coincides with the projection of the second protrusion 52 along the thickness direction of the cover plate 10, and the dimension of the overlapping portion in the radial direction of the pole post 30 is W, which satisfies W≥0.1mm.

[0084] The overlapping portion must have a radial dimension of 0.1 mm or greater than or equal to that of the terminal post 30. If the overlapping dimension W is too small (e.g., less than 0.1 mm), it indicates that the overlap area between the lower insulator 20 and the second protrusion 52 is too narrow. This can easily lead to misalignment between the lower insulator 20 and the second protrusion 52, re-exposing gaps and causing the insulation to fail to prevent leakage. Therefore, limiting the overlapping portion dimension W to 0.1 mm or greater helps maintain the stability of the sealing ring 50 structure, avoids or reduces electrolyte seepage into the top cover, and thus improves battery safety.

[0085] It is understood that the specific value of the dimension W of the overlapping part can be 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, etc., and this embodiment does not impose a specific numerical limit on it.

[0086] In some embodiments, see Figures 5 to 6 The sealing body 51 is sleeved on the outer periphery of the pole body 31. Along the radial direction of the pole body 31, the radius of the inner edge of the sealing body 51 near the pole body 31 is R4, and the radius of the outer periphery of the pole body 31 is R5, satisfying: 0.05mm≤R4-R5≤0.5mm.

[0087] Specifically, limiting R4-R5 to between 0.05mm and 0.5mm helps to balance the concentricity of the sealing ring 50 during assembly and installation. If the difference R4-R5 is too small (e.g., less than 0.05mm), the sealing ring 50 is prone to generating significant frictional resistance when fitted into the pole body 31. This interference fit or extremely small clearance can lead to assembly difficulties. If the difference R4-R5 is too large (e.g., greater than 0.5mm), the gap between the pole body 31 and the sealing ring 50 is too large. In this case, after assembly, the sealing ring 50 is prone to eccentricity, which can easily reduce the overall sealing reliability of the top cover assembly 100.

[0088] It is understood that the specific values ​​of the difference R4-R5 can be 0.05mm, 0.08mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc., and this embodiment does not impose specific numerical limitations on them.

[0089] Secondly, such as Figure 8 As shown, Figure 8 This is a schematic diagram of the battery 200 disclosed in the embodiments of this application. This application also discloses a battery 200, which includes a top cover assembly 100 as described in the first aspect.

[0090] Specifically, the battery 200 has the aforementioned top cover assembly 100. Therefore, by providing multiple first protrusions 22 on the lower insulating member 20 to support the connecting piece 40, and by leaving venting channels 23 between adjacent first protrusions 22, high-temperature gases generated during welding can be discharged, thereby reducing the risk of bursting at the weld between the electrode post 30 and the connecting piece 40. Simultaneously, by controlling the distance between the first protrusions 22 and the weld between the electrode post 30, and by providing overlapping structures between the lower insulating member 20 and the sealing ring 50, channels for electrolyte to seep into the top cover can be blocked, improving insulation safety performance. It is evident that the top cover assembly 100 of this application, while improving the welding quality between the electrode post 30 and the connecting piece 40, also enhances the sealing and insulation performance of the structure, which is beneficial for improving the overall structural stability and safety performance of the battery 200.

[0091] It is understood that the battery 200 may include secondary batteries of the types such as lithium-ion batteries, sodium-ion batteries, nickel-metal hydride batteries, solid-state batteries or lead-acid batteries, and this embodiment does not make specific type limitations.

[0092] Thirdly, such as Figure 9 As shown, Figure 9 This is a schematic diagram of an energy storage device disclosed in an embodiment of this application. This application also discloses an energy storage device 300, which includes a battery 200 as described in the second aspect.

[0093] The energy storage device 300 includes the battery 200 in the aforementioned embodiments, thus enabling the realization of the beneficial effects corresponding to the battery 200 and its top cover assembly 100. The energy storage device 300 of this application, while ensuring high-strength internal electrical connections, also improves the safety, stability, and reliability of the energy storage system 400 during long-term operation.

[0094] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve energy efficiency, it is necessary to store one form of energy in the same way or by converting it into another, and then release it in a specific energy form based on future application needs. Currently, the main way to generate green electricity is to develop green energy sources such as photovoltaics and wind power to replace fossil fuels.

[0095] Currently, the generation of green electricity generally relies on solar, wind, and hydropower. However, wind and solar power are generally characterized by strong intermittency and large fluctuations, which can cause grid instability, insufficient power during peak demand periods, and excessive power during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar curtailment." Solving these problems requires energy storage. This involves converting electrical energy into other forms of energy through physical or chemical means and storing it. When needed, this energy can be converted back into electrical energy and released. Simply put, energy storage is like a large "power bank," storing electrical energy when solar and wind power are abundant and releasing the stored electricity when needed.

[0096] Taking electrochemical energy storage as an example, this solution provides an energy storage device 300, which is applied to an energy storage system 400. The energy storage device 300 contains a battery, which adopts the battery with a gas-conducting structure as described in the previous embodiment. It mainly utilizes the chemical elements inside the battery as the energy storage medium. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. Simply put, it stores the electrical energy generated by wind and solar energy in the battery, and releases the stored electricity for use when the external power consumption reaches its peak, or transfers it to areas with power shortages.

[0097] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, and consumption-side energy storage. The corresponding energy storage devices (300 types) include: (1) Large-scale energy storage power stations applied to wind power and photovoltaic power stations can help renewable energy power generation meet grid connection requirements and improve the utilization rate of renewable energy. As a high-quality active / reactive power regulation power source on the power supply side, energy storage power stations can achieve load matching of power in time and space, enhance the absorption capacity of renewable energy, reduce instantaneous power changes, reduce the impact on the power grid, improve the absorption of new energy power generation, and are of great significance in power grid system backup, alleviating peak load power supply pressure and peak regulation and frequency regulation.

[0098] (2) Energy storage containers applied on the grid side mainly function as peak shaving, frequency regulation and grid congestion relief. In terms of peak shaving, they can achieve peak shaving and valley filling of electricity load, that is, charging the battery when the electricity load is low and releasing the stored electricity during the peak period of electricity load, thereby achieving a balance between power production and consumption.

[0099] (3) Small energy storage cabinets applied to the electricity consumption side mainly function as self-generation and self-consumption of electricity, peak-valley price arbitrage, capacity cost management, and improvement of power supply reliability. Depending on the application scenario, electricity consumption side energy storage can be divided into industrial and commercial energy storage cabinets, household electrical equipment, energy storage charging piles, etc., which are generally used in conjunction with distributed photovoltaics. Industrial and commercial users can use energy storage for peak-valley price arbitrage and capacity cost management. In the electricity market implementing peak-valley pricing, by charging the energy storage system 400 when the electricity price is low and discharging the energy storage system 400 when the electricity price is high, peak-valley price arbitrage can be achieved, reducing electricity costs. In addition, industrial enterprises subject to two-part tariffs can use the energy storage system 400 to store energy during the low electricity consumption period and discharge during the peak load period, thereby reducing peak power and the maximum demand declared, and achieving the goal of reducing capacity electricity costs. Household photovoltaics with energy storage can improve the level of self-generation and self-consumption of electricity. Due to high electricity prices and poor power supply stability, the demand for household photovoltaic installations is driven. Given that photovoltaic power generation occurs during the day, while user load is generally higher at night, configuring energy storage can better utilize photovoltaic power, improve self-consumption levels, and reduce electricity costs. Furthermore, energy storage is needed in areas such as communication base stations and data centers for backup power.

[0100] Fourthly, such as Figure 10 As shown, Figure 10 This is a schematic diagram of the energy storage system disclosed in an embodiment of this application. This application also discloses an energy storage system 400, which includes an energy storage device 300 as described in the third aspect.

[0101] This application provides an energy storage system 400, which includes: a high-voltage cable, a first power conversion device, a second power conversion device, and an energy storage device 300 provided in this application. In some embodiments of the power generation scenario, the second power conversion device can be a wind power conversion device. Since the electricity generated by wind power conversion is volatile, random, and intermittent, the unstable electricity output by the wind power conversion device can be stored in the energy storage device 300 through grid connection. The energy storage device 300 is connected to the high-voltage cable and outputs smooth electricity to the power consumption side of the distribution network, realizing peak shaving and frequency regulation, and stable grid operation; or, the wind power conversion device... Always connected to high-voltage cables, under normal power generation conditions, the power output from the wind power conversion device is supplied to the power consumption side of the distribution network via the high-voltage cables. When the current power load is low and the wind power conversion device generates excess power, the excess power is first stored in the energy storage device 300, reducing the curtailment rate of wind and solar power and improving the problem of new energy power generation consumption. When the power load is high, the power grid issues an instruction to transmit the power stored in the energy storage device 300 together with the high-voltage cables in grid-connected mode to supply power to the power consumption side, providing multiple services such as peak shaving, frequency regulation, and backup for power grid operation, giving full play to the peak shaving role of the power grid, promoting peak shaving and valley filling of the power grid, and alleviating the power supply pressure of the power grid.

[0102] In some embodiments on the distribution network side, the first power conversion device can be a photovoltaic power conversion device. The energy storage device 300 is connected to the high-voltage cable and installed downstream of the high-voltage cable between the user load and the user load. The power output by the photovoltaic power conversion device is stored in the energy storage device 300, which can respond in a timely manner to act as a backup power source when the power grid / distribution network fails. Alternatively, it can provide power supply support to alleviate line congestion when the high-voltage cable transmission line is blocked, and to delay the economic pressure caused by the expansion of the power grid / distribution capacity when the power grid is planned to be expanded.

[0103] Optionally, the first power conversion device may include, but is not limited to, a wind power conversion device, and the second power conversion device may include, but is not limited to, a photovoltaic power conversion device. The first power conversion device and the second power conversion device can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy, and mechanical energy into electrical energy.

[0104] Optionally, the battery may include, but is not limited to, energy storage applications such as energy storage power stations, hydropower / thermal / wind power generation systems, solar power generation systems, mobile power systems, smart home systems, or temporary power supply systems, and may also be used in multiple fields such as data centers, military equipment, aerospace, charging piles, and electric vehicles.

[0105] Optionally, the battery may include, but is not limited to, a single cell, or a battery module, battery pack, battery cluster, power bank, energy storage cabinet / energy storage container, or other integrated battery system composed of single cells. The actual application form of the battery provided in this application embodiment may be, but is not limited to, the listed products, and may also be other application forms. This application embodiment does not strictly limit the application form of the battery. This application embodiment only uses a multi-cell battery as an example for illustration.

[0106] Optionally, the battery can be a rechargeable battery, which refers to a battery cell that can be recharged after discharge to activate the active materials and continue to be used. The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application does not specifically limit its type.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A top cover assembly, characterized in that, The top cover assembly includes: Cover plate; A lower insulating component is disposed on one side surface of the cover plate, and the lower insulating component is provided with a first pole post through hole; The electrode post is inserted through the cover plate and the first electrode post through hole; A connecting piece is located on the side of the lower insulating member away from the cover plate, and the connecting piece is welded to one end of the pole that passes through the hole of the first pole. The lower insulating member has a plurality of first protrusions that protrude toward and abut against the connecting piece. The plurality of first protrusions are arranged around the outer periphery of the first pole post through hole. An exhaust channel is formed between two adjacent first protrusions. The exhaust channel is configured to connect the connection between the pole post and the connecting piece and the external environment. The sum of the maximum arc lengths of the plurality of first protrusions along the circumference of the first pole post through hole is L1, and the sum of the maximum arc lengths of the plurality of exhaust channels along the circumference of the first pole post through hole is L2, satisfying: 0.7≤L1 / (L1+L2)≤0.

95.

2. The top cover assembly according to claim 1, characterized in that, The lower insulating member has a first surface facing the connecting piece and a second surface opposite to the first surface, the first pole post through hole penetrates the first surface and the second surface, and a plurality of first boss portions are provided on the first surface; The first surface is also provided with an exhaust groove located between the first pole post through hole and the plurality of first protrusion portions, and the exhaust groove is connected to the exhaust channel and the first pole post through hole.

3. The top cover assembly according to claim 2, characterized in that, The first boss portion and the first pole post through hole are connected by an inclined surface. The inclined surface is inclined from the outer periphery of the first pole post through hole toward the first boss portion, so that the first boss portion and the first pole post through hole form the exhaust groove that is widened along the thickness direction of the cover plate. The inclined surface is configured as the inner wall surface of the exhaust groove.

4. The top cover assembly according to claim 3, characterized in that, The welding point between the connecting piece and the pole post forms an annular welding trajectory with a radius of R1. The radius of the inner edge of the first protrusion near the through hole of the first pole post is R2, and the radius of the outer edge of the first protrusion away from the through hole of the first pole post is R3, wherein R2 < R3. Satisfying: 4mm ≤ R2 - R1 ≤ 15mm; and / or, The following condition must be met: 4mm≤R3-R1≤15mm.

5. The top cover assembly according to claim 1, characterized in that, The welding point between the connecting piece and the pole post forms an annular welding trajectory with a radius of R1. The radius of the inner edge of the first protrusion near the through hole of the first pole post is R2, and the radius of the outer edge of the first protrusion away from the through hole of the first pole post is R3, wherein R2 < R3. Satisfying: 4mm ≤ R2 - R1 ≤ 15mm; and / or, Satisfying: 4mm ≤ R3 - R1 ≤ 15mm; and / or, Satisfies: 1mm≤R3-R2.

6. The top cover assembly according to claim 1, characterized in that, The number of the first protrusions is at least three, and they are arranged at equal intervals along the circumference of the first pole post perforation; and / or, The sum of the maximum arc lengths of the multiple first boss portions along the circumferential direction of the first pole post perforation is L1, which satisfies: 30mm≤L1≤80mm.

7. The top cover assembly according to claim 1, characterized in that, The pole includes a pole body and a first protrusion. The first protrusion protrudes from the outer peripheral surface of the pole body along the radial direction of the pole. The pole body and the first protrusion pass through the first pole hole, so that the first protrusion is located between the lower insulating member and the connecting piece along the thickness direction of the cover plate. The top cover assembly also includes a sealing ring, which includes a sealing body and a second protrusion disposed on the sealing body. The sealing body is sleeved on the outer periphery of the pole body and is pressed between the cover plate and the pole body along the thickness direction of the cover plate. The second protrusion protrudes along the outer periphery of the sealing body and is pressed between the lower insulating member and the first protrusion along the thickness direction of the cover plate. The orthographic projection of the lower insulating member along the thickness direction of the cover plate at least partially overlaps with the projection of the second protrusion along the thickness direction of the cover plate, and the overlapping part has a dimension W in the radial direction of the pole post, satisfying: W≥0.1mm.

8. The top cover assembly according to claim 1, characterized in that, The connecting piece is provided with a second electrode post through hole for the electrode post to pass through. Along the radial direction of the electrode post, there is a gap X between the inner wall surface of the second electrode post through hole and the outer circumferential surface of the electrode post, satisfying: 0.05mm ≤ X ≤ 3mm; and / or, The connecting piece has a third surface opposite to the lower insulator and a fourth surface opposite to the third surface. The fourth surface has a second pole hole that extends through the third surface and is used for the pole to pass through. The third surface has a groove located on the outer periphery of the second pole hole. Along the thickness direction of the cover plate, the end face of the pole that passes through the second pole hole is located in the groove and does not protrude from the third surface of the connecting piece.

9. A battery, characterized in that, include: The top cover assembly as described in any one of claims 1-8.

10. An energy storage device, characterized in that, The energy storage device includes the battery as described in claim 9.

11. An energy storage system, characterized in that, The energy storage system includes the energy storage device as described in claim 10.

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