Top cover assembly, energy storage device and energy storage system

Abstract

This application discloses a top cover assembly, an energy storage device, and an energy storage system. The top cover assembly includes a top cover plate, a lower plastic component, an electrode post, an upper plastic component, a pressure ring, and a limiting structure. The top cover plate has a first through hole. The lower plastic component is connected to the top cover plate and has a second through hole corresponding to the first through hole, with the first through hole communicating with the second through hole. The electrode post passes through both the first and second through holes. The upper plastic component is located on the outer periphery of the electrode post and passes through both the first and second through holes, and is connected to the top cover plate. The pressure ring is located in a first mounting groove and connected to the electrode post, with a gap forming between the pressure ring and the groove wall of the first mounting groove. The limiting structure is configured to restrict the axial rotation of the pressure ring relative to the first mounting groove along the first through hole.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a top cover assembly, an energy storage device, and an energy storage system. Background Technology

[0002] In related technologies, the top cover assembly of an energy storage device (such as a battery) is often used to seal the battery cell, thereby preventing the electrolyte inside from leaking out and ensuring the normal use of the battery.

[0003] In existing top cover assembly components, during welding of the pressure ring to the terminal post, heat from the pressure ring may be transferred to the lower plastic component, causing it to melt. This can damage the lower plastic structure, affecting the proper installation of the pressure ring, compromising the sealing effect between the lower plastic and the terminal post / pressure ring, leading to electrolyte leakage and affecting the normal use of the battery. Summary of the Invention

[0004] This application discloses a top cover assembly, an energy storage device, and an energy storage system to improve the poor installation effect of the pressure ring caused by the hot melting of the lower plastic.

[0005] To achieve the above objectives, in a first aspect, this application discloses a top cover assembly, comprising:

[0006] Top cover plate, wherein the top cover plate has a first through hole;

[0007] The lower plastic is connected to the top cover plate. The lower plastic has a second through hole corresponding to the first through hole, and the second through hole is connected to the first through hole. The lower plastic has a first mounting groove on the side facing away from the top cover plate. The first mounting groove is arranged around the outer periphery of the second through hole.

[0008] A pole post, wherein the pole post passes through the first through hole and the second through hole;

[0009] The upper plastic is disposed on the outer periphery of the pole post and passes through the first through hole and the second through hole, and the upper plastic is connected to the top cover plate;

[0010] A pressure ring, wherein the pressure ring is disposed in the first mounting groove, the pressure ring is connected to the pole post, and the outer peripheral surface of the pressure ring forms a gap with the groove wall surface of the first mounting groove; and

[0011] A limiting structure is configured to restrict the pressure ring from rotating relative to the first mounting groove in the axial direction about the first through hole.

[0012] In the top cover assembly disclosed in this application, a pressure ring is installed in the first mounting groove of the lower plastic. The pressure ring is connected to the bottom surface of the first mounting groove, and a gap is formed between the pressure ring and the groove wall surface of the first mounting groove. When the pressure ring is being welded, the gap can prevent heat from being transferred from the pressure ring to the groove wall surface of the first mounting groove, thereby reducing or avoiding local heat melting of the lower plastic due to the welding of the pressure ring. Furthermore, considering that the groove wall surface of the first mounting groove is unlikely to provide torque to the pressure ring after the gap is formed between the pressure ring and the groove wall surface, the pressure ring may twist within the first mounting groove. Therefore, this application also provides a limiting structure to restrict the pressure ring from rotating axially around the first through hole within the first mounting groove, thereby preventing the pressure ring from twisting within the first mounting groove and effectively ensuring the reliability of the connection between the pressure ring, the pole, and the lower plastic.

[0013] As an alternative implementation, the limiting structure is formed within the spacing.

[0014] When the limiting structure is located within the gap, if the pressure ring twists relative to the first mounting groove at the gap, the limiting structure can directly lock the pressure ring, making it difficult for the pressure ring to rotate at the gap. This prevents the pressure ring from rotating within the first mounting groove.

[0015] On the other hand, when the pressure ring is heated during welding, even if the heat on the pressure ring reaches the gap, it will be directly transferred to the limiting structure. The limiting structure will melt after being heated, and the melted limiting structure can fill the gap. While maintaining the limiting structure's limitation on the pressure ring, it can also reduce or even prevent the heat on the pressure ring from being transferred to the lower plastic, thereby weakening the impact of the heat on the pressure ring on the lower plastic.

[0016] As an optional implementation, the limiting structure is disposed on the pressure ring, and / or the limiting structure is disposed on the first mounting groove.

[0017] When the limiting structure is located at the pressure ring and / or the first mounting groove, it can be engaged with the groove wall of the first mounting groove, or with the outer circumferential surface of the pressure ring, or the two limiting structures can engage with each other. This allows the pressure ring to be limited within the first mounting groove, effectively preventing rotation within the groove.

[0018] As an optional implementation, the outer peripheral surface of the pressure ring is configured as a non-circular surface, the limiting structure protrudes from the bottom surface of the first mounting groove, and the limiting structure is close to or abuts against the outer peripheral surface of the pressure ring to restrict the axial rotation of the pressure ring relative to the first mounting groove about the first through hole.

[0019] When the outer circumferential surface of the pressure ring is non-circular, a limiting structure abuts against it, generating torque to restrict rotation within the first mounting groove. Furthermore, the limiting structure, positioned within the spacing, is simple in design and primarily relies on the torque generated by the non-circular outer circumferential surface of the pressure ring to limit rotation, minimizing its footprint in the first mounting groove. In other words, the limiting structure effectively limits the pressure ring while minimizing its footprint in the first mounting groove, facilitating pressure ring installation.

[0020] As an optional implementation, the limiting structure is provided around the outer peripheral surface of the pressure ring, or...

[0021] The outer peripheral surface of the pressure ring has multiple corners, and the limiting structure includes multiple limiting parts. The multiple limiting parts are spaced apart along the outer peripheral surface of the pressure ring, and each limiting part is respectively provided for each corner.

[0022] When the limiting structure completely covers the outer circumference of the pressure ring, it increases the torque between the limiting structure and the outer circumference of the pressure ring, thereby limiting the torsion of the pressure ring and improving its limiting effect. When the pressure ring is a polygon such as a square or pentagon, each limiting part is set at each corner, so that the limiting part can cover the outer circumference of the corners to provide torque for rotation, thereby limiting the rotation of the pressure ring. In other words, when the pressure ring has corners, limiting parts can be set only at the corners of the pressure ring, which can not only achieve the same limiting effect on the pressure ring, but also provide precise limiting positions.

[0023] As an optional implementation, the limiting structure has an end face along the axial direction of the first through hole, the end face extending to connect with the bottom surface of the first mounting groove to form a first stepped surface, and the outer peripheral surface of the pressure ring forms a second stepped surface, the first stepped surface and the second stepped surface engaging and connecting.

[0024] When the first stepped surface and the second stepped surface are connected, the first stepped surface can provide torque to the second stepped surface during rotation, thereby preventing the pressure ring from rotating within the first mounting groove. For example, when the first stepped surface and the second stepped surface are connected at any position on the outer circumference of the pressure ring, both the first and second stepped surfaces can generate torque. That is, by using the stepped surface connection method, when the limiting structure is connected to the pressure ring, the rotation of the pressure ring can be restricted whether the limiting structure is set at any position within the spacing or when it is set around the entire outer circumference of the pressure ring, thus providing good limiting reliability.

[0025] As an alternative implementation, the outer peripheral surface of the pressure ring is provided with a groove, the inner wall surface of the groove is configured as the second stepped surface, and the limiting structure is at least partially located in the groove so that the first stepped surface approaches or abuts against the second stepped surface.

[0026] The second step is formed by the inner wall of the groove. When the limiting structure extends into the groove, the inner wall of the groove can be adapted to the shape of the first step. When the pressure ring is connected to the limiting structure, the first step and the second step can be matched to restrict the rotation of the pressure ring and effectively prevent the pressure ring from twisting.

[0027] As an alternative implementation, along the radial direction of the first through hole, the side of the limiting structure opposite to the outer peripheral surface of the pressure ring is spaced apart from the groove wall surface of the first mounting groove.

[0028] When a limiting structure is installed within the spacing, the limiting structure abuts against the pressure ring to restrict its rotation. Furthermore, the limiting structure is spaced apart from the wall of the first mounting groove. Most of the heat from the pressure ring is transferred to the limiting structure, making it difficult for it to be transferred back to the wall of the first mounting groove. This reduces the impact of the pressure ring's heat on the lower plastic component, preventing damage to the lower plastic structure due to heat melting.

[0029] As an alternative implementation, along the radial direction of the first through hole, the side of the limiting structure opposite to the outer peripheral surface of the pressure ring is connected to the groove wall surface of the first mounting groove.

[0030] When the limiting structure is a boss, the boss is connected to the groove wall of the first mounting groove along the radial direction of the first through hole, so that the limiting structure fills the gap. For example, if the limiting structure uses heat insulation material, when the limiting structure fills the gap, the limiting structure can form a thermal barrier between the groove wall of the first mounting groove and the outer peripheral surface of the pressure ring, which helps to reduce the heat transfer of the pressure ring to the lower plastic and prevent the structure of the lower plastic from being damaged by heat melting.

[0031] As an optional implementation, the limiting structure includes a protrusion and a recess, one of the pressure ring and the first mounting groove is provided with the protrusion, and the other is provided with the recess, and the protrusion is engaged with the recess.

[0032] This application utilizes a convex-concave fitting locking structure. When the pressure ring rotates axially around the first through hole, the convex portion abuts against the inner wall of the concave portion, thereby restricting the rotation of the pressure ring. Furthermore, the convex-concave fitting connection is simple and advantageous for installation in relatively confined spaces. Therefore, the convex-concave fitting locking structure not only effectively limits the pressure ring but also saves space in the first mounting groove, facilitating the installation of the pressure ring.

[0033] As an optional implementation, the pressure ring is provided with the protrusion, and the side wall of the first mounting groove is provided with two protrusions, which are spaced apart to form the recess. The outer peripheral surface of the protrusions and / or the protrusions is configured as an arc surface.

[0034] When the first mounting groove has two protrusions, a protrusion is provided on the outer circumferential surface of the pressure ring, extending into the recess. The outer circumferential surfaces of the two protrusions abut against each other. When both outer circumferential surfaces are curved, the protrusions can slide between the two protrusions along the guide of the curved surface, thereby facilitating the limiting installation of the pressure ring in the first mounting groove. On the other hand, when the two protrusions are connected to the protrusion on the pressure ring, the curved surfaces on the two protrusions form a line contact with the curved surfaces on the protrusion. Compared with surface contact, the contact area of ​​the line contact is smaller, which can effectively reduce the heat transfer between the pressure ring and the limiting structure, and is beneficial to improving the heat melting of the lower plastic.

[0035] As an optional implementation, the limiting structure protrudes from the bottom surface of the first mounting groove along the axial direction of the first through hole, the thickness of the limiting structure is d1, and the thickness of the pressure ring is d2, wherein d1 < d2.

[0036] Taking a limiting structure made of the same plastic material as the lower plastic as an example, when the heat from the pressure ring is transferred to the limiting structure, the limiting structure can melt. If the thickness d1 of the limiting structure is greater than the thickness d2 of the pressure ring, the limiting structure will protrude from the gap along the direction of the first through hole. If the limiting structure melts, the molten limiting structure may flow to the surface of the pressure ring or the lower surface of the lower plastic, resulting in material loss of the limiting structure and making it difficult to limit the pressure ring within the gap. In other words, when d1 is less than d2, the limiting structure melts within the gap, which can prevent the melted limiting structure from flowing out of the gap, thus helping the limiting structure maintain its limiting effect on the pressure ring within the gap.

[0037] As an optional implementation, the top cover plate is provided with a second mounting groove on the side facing the lower plastic, and the second mounting groove is arranged around the outer periphery of the first through hole;

[0038] The top cover assembly also includes a sealing element, which is sleeved on the outer periphery of the upper plastic and located in the second mounting groove. Along the axial direction of the first through hole, the sealing element is connected between the pressure ring and the top cover plate.

[0039] To ensure a sealed installation between the pressure ring, the electrode post, and the lower plastic, and to prevent the electrolyte from leaking out of the energy storage device, this application includes a sealing element. The sealing ring effectively seals the pressure ring, the electrode post, and the lower plastic.

[0040] As an optional implementation, the limiting structure is disposed in the first mounting groove and protrudes from the bottom surface of the first mounting groove, the sealing member is connected between the pressure ring and the top cover plate, the pressure ring compresses the sealing member along the axial direction of the first through hole, the compression amount of the sealing member is d3, and the thickness of the limiting structure is d1, wherein d1 > d3;

[0041] The thickness of the seal is D1, and the thickness of the seal after compression is D2, where D1-D2=d3.

[0042] When the pressure ring is installed, the seal can be compressed by the pressure ring. If the thickness of the limiting structure is greater than the compressed thickness of the seal, the pressure ring can form a connection with the limiting structure. Conversely, if the thickness of the limiting structure is less than the compressed thickness of the seal, the seal will still be thick enough after compression to push up the pressure ring, making it difficult for the pressure ring to form a limiting connection with the limiting structure. In other words, when the thickness of the limiting structure is greater than the compressed thickness of the seal, it is beneficial for the pressure ring to form a limiting connection with the limiting structure, preventing the limiting structure from failing to limit the seal.

[0043] As an alternative implementation, the upper plastic is engaged with at least one of the top cover plate, the pole post, and the pressure ring.

[0044] Considering that the pressure ring may twist and cause the electrode post to rotate, in order to further improve the anti-torsion effect of the pressure ring and even the electrode post, this application sets the upper plastic to be engaged with the top cover plate, the electrode post and the pressure ring, so as to use the upper plastic to limit the electrode post and the pressure ring, thereby preventing the pressure ring and the electrode post from rotating.

[0045] As an optional implementation, when the upper plastic is engaged with the top cover plate, the pole post, and the pressure ring, the upper plastic has a first engaging portion on the side near the pole post, and the pole post has a first mating portion corresponding to the first engaging portion. One of the first engaging portion and the first mating portion is a first protrusion, and the other is a first recess.

[0046] The upper plastic is provided with a second snap-fit ​​part on the side near the top cover plate, and the top cover plate is provided with a second mating part corresponding to the second snap-fit ​​part. One of the second snap-fit ​​part and the second mating part is a second protrusion, and the other is a second recess.

[0047] The upper plastic is provided with a third snap-fit ​​portion on the side near the pressure ring, and the pressure ring is provided with a third mating portion corresponding to the third snap-fit ​​portion. One of the third snap-fit ​​portion and the third mating portion is a third protrusion, and the other is a third recess.

[0048] The upper plastic and the top cover plate, pole post and pressure ring are connected by their own structure. When the upper plastic is installed with the top cover plate, pole post and pressure ring, they can naturally form a lock. This achieves effective locking between the upper plastic and the top cover plate, pole post and pressure ring without taking up additional installation space for the top cover assembly.

[0049] As an optional implementation, the upper plastic has a first side and a second side along the axial direction of the first through hole, the first snap-fit ​​portion is disposed on the first side, and the second snap-fit ​​portion and the third snap-fit ​​portion are both disposed on the second side, and the second snap-fit ​​portion and the third snap-fit ​​portion are offset along the axial direction of the first through hole.

[0050] Since the second and third snap-fit ​​parts are located on the same side, to avoid interference between the second and third snap-fit ​​parts and their corresponding engagement parts, the second and third snap-fit ​​parts are staggered when they are positioned on the upper plastic part. This helps prevent the second snap-fit ​​part from affecting the installation of the third snap-fit ​​part and its engagement part, or vice versa. Furthermore, the staggered arrangement of the second and third snap-fit ​​parts facilitates the alignment and installation of the upper plastic part with the top cover plate and the pressure ring, making the positioning and installation of the upper plastic part easier.

[0051] As an optional implementation, the top cover assembly further includes a seal. When the third snap-fit ​​portion is a third protrusion, the seal is located between the third snap-fit ​​portion and the sidewall of the second through hole along the axial direction of the first through hole. The thickness of the seal is D1, and the thickness of the third snap-fit ​​portion is d4, wherein D1 < d4.

[0052] After being compressed, the seal can move within the space formed by the pressure ring, the third snap-fit ​​part, and the groove wall of the second mounting groove. Due to the large thickness of the third snap-fit ​​part, it blocks one side of the seal's movement space. Above the groove wall of the second mounting groove is the groove wall of the first mounting groove, which blocks the other side of the seal's movement space. The seal is also blocked above by the pressure ring. In this way, the movement space of the seal is restricted when it deforms, which helps to reduce the risk of the seal coming out of the second mounting groove when it is compressed by the pressure ring, and helps to improve the sealing effect of the seal.

[0053] Secondly, this application also discloses an energy storage device, comprising:

[0054] case;

[0055] The battery cell, wherein the battery cell is disposed within the housing; and

[0056] According to the top cover assembly described in the first aspect, the top cover assembly is configured to cover the housing.

[0057] When the top cover assembly disclosed in the first aspect is installed in an energy storage device, the outer peripheral surface of the pressure ring of the top cover assembly is spaced apart from the wall surface of the first mounting groove of the lower plastic. This helps to reduce the heat melting of the lower plastic and prevents the structure of the lower plastic from being affected, which could lead to a decrease in the sealing performance of the top cover assembly and cause electrolyte leakage from the energy storage device. Furthermore, a limiting structure is provided within the gap between the outer peripheral surface of the pressure ring and the wall surface of the first mounting groove to restrict the pressure ring from twisting at the gap, preventing the pressure ring from twisting and causing a deterioration in the sealing effect between the pressure ring, the lower plastic, and the electrode post, thus avoiding electrolyte leakage. In addition, to prevent the twisting of the pressure ring from causing the electrode post to rotate, this application also designs a snap-fit ​​structure for the upper plastic to further prevent the pressure ring and electrode post from twisting and causing a deterioration in the sealing effect of the top cover assembly.

[0058] Thirdly, this application also discloses an energy storage system, including the energy storage device described in the second aspect.

[0059] In energy storage systems, the top cover assembly of the energy storage device can improve the heat melting of the lower plastic by setting the distance between the pressure ring and the lower plastic, and prevent the pressure ring and the electrode post from twisting by using the limiting structure and the snap-fit ​​design of the upper plastic, thereby improving the leakage (electrolyte) problem of the energy storage device that may be caused by the twisting of the pressure ring and the electrode post.

[0060] Compared with the prior art, the beneficial effects of this application are as follows:

[0061] This application discloses a top cover assembly, an energy storage device, and an energy storage system. The top cover assembly includes a top cover plate, a lower plastic component, an electrode post, an upper plastic component, a pressure ring, and a limiting structure. The top cover plate has a first through hole. The lower plastic component is connected to the top cover plate and has a second through hole corresponding to the first through hole, with the first through hole communicating with the second through hole. The electrode post passes through both the first and second through holes. The upper plastic component is located on the outer periphery of the electrode post and passes through both the first and second through holes, and is connected to the top cover plate. The pressure ring is located in a first mounting groove and connected to the electrode post, with a gap forming between the pressure ring and the groove wall of the first mounting groove. The limiting structure is configured to restrict the axial rotation of the pressure ring relative to the first mounting groove along the first through hole. The top cover assembly disclosed in this application reduces heat transfer to the lower plastic component during welding of the pressure ring by setting a gap between the pressure ring and the groove wall of the first mounting groove, thus mitigating the possibility of the lower plastic component melting. Furthermore, setting a gap between the pressure ring and the groove wall of the first mounting groove may cause the pressure ring to twist. To address this, a limiting structure is provided to restrict the rotation of the pressure ring and prevent it from twisting. Attached Figure Description

[0062] 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.

[0063] Figure 1 This is a schematic diagram of a top cover assembly disclosed in an embodiment of this application;

[0064] Figure 2 This is another structural schematic diagram of the top cover assembly disclosed in the embodiments of this application;

[0065] Figure 3 This is an exploded view of the top cover assembly disclosed in an embodiment of this application;

[0066] Figure 4 for Figure 2 A schematic diagram of the first structure at point AA;

[0067] Figure 5 This is a schematic diagram of the first structure of the limiting structure disclosed in the embodiments of this application;

[0068] Figure 6 This is a schematic diagram of a second type of limiting structure disclosed in the embodiments of this application;

[0069] Figure 7 This is a schematic diagram of a third type of limiting structure disclosed in the embodiments of this application;

[0070] Figure 8 for Figure 2 A schematic diagram of the second structure at point AA;

[0071] Figure 9 This is a schematic diagram of the fourth type of limiting structure disclosed in the embodiments of this application;

[0072] Figure 10 for Figure 2 A schematic diagram of the third structure at point AA;

[0073] Figure 11 for Figure 2 A schematic diagram of the fourth structure at point AA;

[0074] Figure 12 This is another exploded view of the top cover assembly disclosed in an embodiment of this application;

[0075] Figure 13 This is a schematic diagram of the structure of the upper plastic disclosed in the embodiments of this application;

[0076] Figure 14This is a schematic diagram of the energy storage device disclosed in the embodiments of this application;

[0077] Figure 15 This is a schematic diagram of an energy storage system disclosed in an embodiment of this application.

[0078] Explanation of reference numerals in the attached figures:

[0079] 101. Top cover assembly; 1. Top cover plate; 11. First through hole; 12. Second mounting groove; 13. Second mating part; 2. Lower plastic; 21. Second through hole; 22. First mounting groove; 22a. Groove wall of the first mounting groove; 22b. Groove bottom of the first mounting groove; 22c. Spacing; 3. Upper plastic; 31. First snap-fit ​​part; 32. Second snap-fit ​​part; 33. Third snap-fit ​​part; 3a. First side; 3b. Second side; 4. Pole post; 41. First mating part; 5. Pressure ring; 5a. Outer peripheral surface of the pressure ring; 51. Edge; 5b. Second stepped surface; 52. Groove; 53. Third mating part; 6. Limiting structure; 61. Protrusion; 62. Recess; 62a. Raised part; 6a. End face; 6b. First stepped surface; 63. Limiting part; 7. Sealing element;

[0080] 100. Energy storage device; 102. Shell;

[0081] 200. Energy storage system; 201. Power conversion device; 202. First user load; 203. Second user load. Detailed Implementation

[0082] 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.

[0083] 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.

[0084] 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.

[0085] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" 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.

[0086] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (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, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0087] In related technologies, the top cover assembly of an energy storage device (such as a single battery cell or a battery pack composed of multiple battery cells) is often used to seal the cells inside the energy storage device, thereby preventing the electrolyte inside from leaking out and ensuring the normal use of the energy storage device.

[0088] Typically, during pole installation, the pressure ring from the top cover assembly needs to be welded to the pole. During welding, the pressure ring is heated, and this heat can transfer to the lower plastic component it's mounted on, causing it to melt. This can lead to physical degradation or even damage to the lower plastic, hindering proper installation of the pressure ring and pole, affecting the sealing performance of the lower plastic, pressure ring, and pole support, and ultimately impacting the normal operation of the energy storage device.

[0089] This application discloses a top cover assembly, an energy storage device, and an energy storage system. In the top cover assembly, a first mounting groove is provided on the lower plastic layer, and a pressure ring is disposed within the first mounting groove. A gap is provided between the pressure ring and the groove wall of the first mounting groove. When the pressure ring generates heat during welding, the gap between the pressure ring and the groove wall of the first mounting groove reduces the heat transfer from the pressure ring to the lower plastic layer, mitigating the possibility of the lower plastic layer melting. This prevents the pressure ring from twisting due to weakened mounting effect of the lower plastic layer on the pressure ring caused by the melting of the lower plastic layer.

[0090] Furthermore, considering that setting a gap between the pressure ring and the groove wall of the first mounting groove weakens the connection between the outer circumferential surface of the pressure ring and the groove wall of the first mounting groove, the torque provided by the groove wall of the first mounting groove to the outer circumferential surface of the pressure ring is reduced. Therefore, when the pressure ring is subjected to external force and may rotate, the lower plastic layer cannot effectively restrict the rotation of the pressure ring. To address this, this application provides a limiting structure to restrict the rotation of the pressure ring within the first mounting groove.

[0091] The technical solution of this application will be further described below with reference to the embodiments and accompanying drawings.

[0092] Firstly, please refer to the following: Figures 1 to 4 This application discloses a top cover assembly 101, including a top cover plate 1, a lower plastic 2, an upper plastic 3, a pole post 4, a pressure ring 5, and a limiting structure 6. The top cover plate 1 has a first through hole 11. The lower plastic 2 is connected to the top cover plate 1, and the lower plastic 2 has a second through hole 21 corresponding to the first through hole 11, and the second through hole 21 communicates with the first through hole 11. The side of the lower plastic 2 facing away from the top cover plate 1 has a first mounting groove 22, which is arranged around the outer periphery of the second through hole 21. The pole post 4 passes through the first through hole 11 and the second through hole 21. The upper plastic 3 is located on the outer periphery of the pole post 4, passing through the first through hole 11 and the second through hole 21, and is connected to the top cover plate 1. The pressure ring 5 is located in the first mounting groove 22 and is connected to the pole post 4. The outer peripheral surface 5a of the pressure ring and the groove wall surface 22a of the first mounting groove form a distance 22c. The limiting structure 6 is configured to restrict the pressure ring 5 from rotating relative to the first mounting groove 22 in the axial direction around the first through hole 11.

[0093] In the top cover assembly 101 disclosed in this application, a pressure ring 5 is installed in the first mounting groove 22 of the lower plastic 2. The pressure ring 5 is connected to the bottom surface 22b of the first mounting groove, and a gap 22c is formed between the pressure ring 5 and the groove wall surface 22a of the first mounting groove. When the pressure ring 5 is being welded, the gap 22c can prevent heat from being transferred from the pressure ring 5 to the groove wall surface 22a of the first mounting groove, thereby reducing the possibility of the pressure ring 5 causing the lower plastic 2 (groove wall surface 22a of the first mounting groove) to melt. Moreover, considering that the groove wall surface 22a of the first mounting groove is difficult to provide torque to the pressure ring 5 after the gap 22c is formed between the pressure ring 5 and the groove wall surface 22a of the first mounting groove, the pressure ring 5 may twist within the first mounting groove 22. To address this, this application provides a limiting structure 6 to restrict the pressure ring 5 from rotating axially around the first through hole 11 within the first mounting groove 22, thereby preventing the pressure ring 5 from twisting within the first mounting groove 22.

[0094] It should be noted that, in Figure 1 In the example, X indicates the axial direction of the first through hole 11, and Y indicates the radial direction of the first through hole 11.

[0095] In some embodiments, the limiting structure 6 is formed within the gap 22c between the outer peripheral surface 5a of the pressure ring and the groove wall surface 22a of the first mounting groove. When the limiting structure 6 is provided within the gap 22c, if the pressure ring 5 twists relative to the first mounting groove 22 at the gap 22c, the limiting structure 6 can lock the pressure ring 5, making it difficult for the pressure ring 5 to rotate at the gap 22c. In this way, rotation of the pressure ring 5 within the first mounting groove 22 can be avoided.

[0096] On the other hand, when the pressure ring 5 is heated during welding, the heat on the pressure ring 5 is transferred to the limiting structure 6. The limiting structure 6 melts after being heated. The melted limiting structure 6 can fill the gap 22c. While maintaining the limiting structure 6's limitation on the pressure ring 5, it can also prevent the heat on the pressure ring 5 from being transferred to the lower plastic 2, thus reducing the influence of the heat on the pressure ring 5 on the melting of the lower plastic 2.

[0097] It is understandable that the limiting structure 6 can be integrally molded with the lower plastic 2 or the pressure ring 5 during production, or the limiting structure 6 can be a separate part, set separately within the spacing 22c.

[0098] Optionally, the limiting structure 6 may be made of plastic or heat insulation material, wherein the heat insulation material may be glass fiber, asbestos, etc., and this application does not make specific limitations.

[0099] Optionally, the limiting structure 6 can be configured as a protrusion, a protrusion, etc., protruding from the bottom surface 22b of the first mounting groove.

[0100] Please see Figure 4 In some embodiments, the limiting structure 6 protrudes from the bottom surface 22b of the first mounting groove along the axial direction of the first through hole 11, the thickness of the limiting structure 6 is d1, and the thickness of the pressure ring 5 is d2, wherein d1 < d2.

[0101] Taking the limiting structure 6 as an example, which uses the same plastic material as the lower plastic 2. If the thickness d1 of the limiting structure 6 is greater than the thickness d2 of the pressure ring 5, the limiting structure 6 will protrude from the gap 22c along the direction of the first through hole 11. When the heat of the pressure ring 5 is transferred to the limiting structure 6, the limiting structure 6 will melt. The melted limiting structure 6 may flow to the surface of the pressure ring 5 or the lower surface of the lower plastic 2, which may not only affect the surface flatness of the pressure ring 5 and the lower plastic 2, but also cause material loss of the limiting structure 6, making it difficult to limit the pressure ring 5 within the gap 22c. In other words, when d1 is less than d2, the limiting structure 6 melts within the gap 22c, which can prevent the melted limiting structure 6 from flowing out of the gap 22c, and is conducive to the limiting structure 6 maintaining its limiting effect on the pressure ring 5 within the gap 22c.

[0102] Optionally, the limiting structure 6 is provided on the pressure ring 5, and / or the limiting structure 6 is provided in the first mounting groove 22.

[0103] In the first example, when the limiting structure 6 is provided on the pressure ring 5, the limiting structure 6 on the pressure ring 5 can engage with the groove wall surface 22a of the first mounting groove, thereby realizing the limiting of the pressure ring 5 within the first mounting groove 22.

[0104] In the second example, when the limiting structure 6 is provided in the first mounting groove 22, the limiting structure 6 in the first mounting groove 22 can engage with the outer peripheral surface 5a of the pressure ring, thereby realizing the limiting of the pressure ring 5 in the first mounting groove 22.

[0105] In the third example, both the pressure ring 5 and the first mounting groove 22 are provided with limiting structures 6. The first limiting structure 6 on the pressure ring 5 and the limiting structure 6 at the first mounting groove 22 are mutually engaged, thereby limiting the pressure ring 5 within the first mounting groove 22.

[0106] When the limiting structure 6 is located at the pressure ring 5 and / or the first mounting groove 22, it can be engaged with the groove wall surface 22a of the first mounting groove, or the limiting structure 6 can be engaged with the outer peripheral surface 5a of the pressure ring, or the two limiting structures 6 can be engaged with each other. In this way, the pressure ring 5 can be limited within the first mounting groove 22, which helps to prevent the pressure ring 5 from rotating within the first mounting groove 22.

[0107] Please see Figure 5 Optionally, the limiting structure 6 includes a protrusion 61 and a recess 62. One of the pressure ring 5 and the first mounting groove 22 is provided with a protrusion 61, and the other is provided with a recess 62. The protrusion 61 is engaged with the recess 62.

[0108] In some examples, the outer peripheral surface 5a of the pressure ring is provided with a protrusion 61, and the groove wall surface 22a or the groove bottom surface 22b of the first mounting groove is provided with a recess 62. The protrusion 61 on the pressure ring 5 is engaged in the recess 62 of the first mounting groove 22.

[0109] In other examples, the outer peripheral surface 5a of the pressure ring is provided with a recess 62, and the groove wall surface 22a of the first mounting groove is provided with a protrusion 61, and the protrusion 61 of the first mounting groove 22 is engaged in the recess 62 of the pressure ring 5.

[0110] This application achieves a snap-fit ​​connection through the concave-convex fit of the limiting structure 6. When the pressure ring 5 rotates axially around the first through hole 11, the protrusion 61 abuts against the inner wall of the recess 62, thereby restricting the rotation of the pressure ring 5. Moreover, the connection through the concave-convex fit is simple and advantageous for installation within a relatively narrow space of 22c. Thus, the limiting structure 6 with the concave-convex fit not only effectively limits the pressure ring 5 but also saves space in the first mounting groove 22, facilitating the installation of the pressure ring 5.

[0111] Optionally, the groove wall surface 22a of the first mounting groove is provided with two protrusions 62a, and the two protrusions 62a are spaced apart to form a recess 62, and the outer peripheral surfaces of the protrusions 62a and / or the protrusions 61 are configured as arc surfaces.

[0112] For example, when the first mounting groove 22 is provided with two protrusions 62a, a protrusion 61 is provided on the outer peripheral surface 5a of the pressure ring. The protrusion 61 extends into the recess 62, and the outer peripheral surfaces of the two protrusions 62a abut against the outer peripheral surfaces of the protrusion 61. When both outer peripheral surfaces are arc surfaces, the protrusion 61 can slide into the space between the two protrusions 62a along the guide of the arc surface, which is beneficial to realize the limiting installation of the pressure ring 5 in the first mounting groove 22. On the other hand, when the two protrusions 62a are limitedly connected to the protrusions 61 on the pressure ring 5, the arc surfaces on the two protrusions 62a and the arc surfaces on the protrusions 61 form a line contact. Compared with the surface contact method, the contact area of ​​the line contact is smaller, which can effectively reduce the heat transfer between the pressure ring 5 and the limiting structure 6, which is beneficial to improve the heat melting of the lower plastic 2.

[0113] In other embodiments, the groove wall 22a of the first mounting groove is provided with a protrusion 62a, which is adapted to conform to the shape of the protrusion 61 on the pressure ring 5 to form a recess 62. This facilitates the positioning and installation of the first mounting groove 22 and the pressure ring 5.

[0114] It is understood that the outer circumferential surface 5a of the pressure ring can be a circular surface or a non-circular surface. The non-circular surface may include, for example, an elliptical outer circumferential surface or a polygonal outer circumferential surface.

[0115] Please see Figure 6 In some embodiments, when the outer peripheral surface 5a of the pressure ring is constructed as a non-circular surface, the limiting structure 6 protrudes from the bottom surface 22b of the first mounting groove, and the limiting structure 6 is close to or abuts against the outer peripheral surface 5a of the pressure ring to restrict the axial rotation of the pressure ring 5 around the first through hole 11. That is, when the outer peripheral surface 5a of the pressure ring is a non-circular surface, the limiting structure 6 abuts against the outer peripheral surface 5a of the pressure ring, causing the limiting structure 6 to generate torque on the outer peripheral surface 5a of the pressure ring, thereby restricting the rotation of the pressure ring 5 within the first mounting groove 22. Moreover, the limiting structure 6 is disposed within the spacing 22c, has a simple structure, and mainly uses the torque generated between the pressure ring 5, whose outer peripheral surface is a non-circular surface, and the limiting structure 6 for limiting, reducing the space occupied by the first mounting groove 22. That is, while effectively limiting the pressure ring 5, the limiting structure 6 can also reduce the space occupied by the first mounting groove 22, facilitating the installation of the pressure ring 5.

[0116] Optionally, the limiting structure 6 is arranged around the outer peripheral surface 5a of the pressure ring. In other words, the limiting structure 6 completely covers the outer peripheral surface 5a of the pressure ring, thereby increasing the torque between the limiting structure 6 and the outer peripheral surface 5a of the pressure ring to limit the torsion of the pressure ring 5, thereby improving the limiting effect of the pressure ring 5.

[0117] Please see Figure 7In some embodiments, the outer peripheral surface 5a of the pressure ring has multiple corners 51, and the limiting structure 6 includes multiple limiting portions 63. The multiple limiting portions 63 are spaced apart along the outer peripheral surface 5a of the pressure ring, and each limiting portion 63 is respectively provided corresponding to each corner 51. For example, when the pressure ring 5 is a polygon such as a square or pentagon, each limiting portion 63 is provided corresponding to each corner 51 position. The limiting portion 63 covers the outer peripheral surface of the corner 51 to provide torque to the corner 51 during rotation, thereby limiting the rotation of the pressure ring 5. That is to say, when the pressure ring 5 has corners 51, the limiting portion 63 can be provided only at the corners 51 of the pressure ring 5, which not only achieves the limiting of the pressure ring 5, but also helps to reduce the setting of the limiting structure 6 and reduce the space occupied by the first mounting groove 22, so as to facilitate the installation of the pressure ring 5.

[0118] Please see Figure 8 and Figure 9 In some embodiments, the limiting structure 6 has an end face 6a along the axial direction of the first through hole 11. The end face 6a extends to connect with the bottom surface 22b of the first mounting groove to form a first stepped surface 6b. The outer peripheral surface 5a of the pressure ring has a second stepped surface 5b, and the first stepped surface 6b and the second stepped surface 5b are engaged. That is, when the first stepped surface 6b and the second stepped surface 5b are engaged, the first stepped surface 6b can provide torque to the second stepped surface 5b when it rotates, so as to prevent the pressure ring 5 from rotating within the first mounting groove 22. For example, when the first stepped surface 6b and the second stepped surface 5b are engaged at any position on the outer peripheral surface 5a of the pressure ring, both the first stepped surface 6b and the second stepped surface 5b can generate torque. That is, by using the stepped surface engagement method to limit the connection between the limiting structure 6 and the pressure ring 5, the rotation of the pressure ring 5 can be limited at any position within the spacing 22c or when the outer peripheral surface 5a of the pressure ring is arranged around the entire circumference, thus having good limiting reliability.

[0119] Optionally, the outer peripheral surface 5a of the pressure ring is provided with a groove 52, and the inner wall surface of the groove 52 is constructed as a second stepped surface 5b. The limiting structure 6 is at least partially located in the groove 52, so that the first stepped surface 6b approaches or abuts against the second stepped surface 5b. Exemplarily, the limiting structure 6 extends into the groove 52, and the inner wall surface of the groove 52 forms a second stepped portion, so that the inner wall surface of the groove 52 is adapted to the shape of the first stepped surface 6b. When the pressure ring 5 is connected to the limiting structure 6, it facilitates the engagement of the first stepped surface 6b and the second stepped surface 5b, thereby limiting the rotation of the pressure ring 5 and preventing the torsion of the pressure ring 5.

[0120] Optionally, each of the multiple limiting portions 63 of the limiting structure 6 has an end face 6a along the axial direction of the first through hole 11. The end face 6a of each limiting portion 63 forms multiple first stepped surfaces 6b with the bottom surface 22b of the first mounting groove. Each first stepped surface 6b can be engaged with a second stepped surface 5b. For example, when the multiple limiting portions 63 of the limiting structure 6 are provided at each corner 51 of the pressure ring 5, the limiting portion 63 can not only restrict the rotation of the pressure ring 5 by abutting against the outer peripheral surface 5a of the pressure ring, but also enhance the limiting effect on the pressure ring 5 by forming a first stepped surface 6b to engage with the second stepped surface 5b of the pressure ring 5.

[0121] Optionally, the limiting structure 6 may consist of multiple limiting parts 63 connected sequentially around the outer periphery of the pressure ring 5, such that the limiting structure 6 is arranged around the entire outer periphery 5a of the pressure ring. Furthermore, while the limiting structure 6 is arranged around the entire outer periphery of the pressure ring 5, it also forms an integral first stepped surface 6b with the bottom surface 22b of the first mounting groove. It can be understood that when the limiting structure 6 is arranged around the entire outer periphery 5a of the pressure ring, the first stepped surface 6b and the second stepped surface 5b also engage and connect around the entire outer periphery 5a of the pressure ring to restrict the rotation of the pressure ring 5. The fully arranged first stepped surface 6b provides a better limiting effect, which is beneficial for improving the effect of restricting the rotation of the pressure ring 5.

[0122] Optionally, the limiting structure 6 may be a plurality of protrusions or protrusions spaced apart on the outer peripheral surface 5a of the pressure ring, or it may be a full circle of protrusions arranged around the outer peripheral surface 5a of the pressure ring.

[0123] Please see Figure 8 In some embodiments, along the radial direction of the first through hole 11, the side of the limiting structure 6 facing away from the outer peripheral surface 5a of the pressure ring is spaced apart from the groove wall surface 22a of the first mounting groove. It is understood that when the limiting structure 6 is provided within the spacing 22c, the limiting structure 6 abuts against the pressure ring 5 to restrict the rotation of the pressure ring 5. Since the limiting structure 6 is spaced apart from the groove wall surface 22a of the first mounting groove, the heat of the pressure ring 5 can only be transferred to the limiting structure 6, and is difficult to transfer to the groove wall surface 22a of the first mounting groove through the limiting structure 6. In this way, the impact of the heat of the pressure ring 5 on the lower plastic 2 can be reduced, preventing the structure of the lower plastic 2 from being damaged due to heat melting.

[0124] Please see Figure 10In other embodiments, along the radial direction of the first through hole 11, the side of the limiting structure 6 facing away from the outer peripheral surface 5a of the pressure ring is connected to the groove wall surface 22a of the first mounting groove. Specifically, when the limiting structure 6 is a boss, the boss is connected to the groove wall surface 22a of the first mounting groove along the radial direction of the first through hole 11, so that the limiting structure 6 fills the gap 22c. For example, if the limiting structure 6 is made of heat-insulating material, when the limiting structure 6 fills the gap 22c, the limiting structure 6 can play a heat-insulating role between the pressure ring 5 and the lower plastic 2, thereby helping to reduce the heat transfer of the pressure ring 5 to the lower plastic 2 and preventing the structure of the lower plastic 2 from being damaged by heat melting.

[0125] Please see Figure 11 In some embodiments, the top cover plate 1 has a second mounting groove 12 on the side facing the lower plastic 2, and the second mounting groove 12 is arranged around the outer periphery of the first through hole 11. The top cover assembly 101 also includes a sealing element 7, which is sleeved on the outer periphery of the upper plastic 3 and located in the second mounting groove 12. Along the axial direction of the first through hole 11, the sealing element 7 is connected between the pressure ring 5 and the top cover plate 1. Considering the sealed installation between the pressure ring 5 and the electrode post 4 and the lower plastic 2 to prevent the electrolyte in the energy storage device 100 from flowing out, this application provides a sealing element 7 to form an effective sealed installation between the pressure ring 5 and the electrode post 4 and the lower plastic 2.

[0126] Optionally, the sealing element 7 may be a sealing ring, sealing block, etc., and this application does not make specific limitations.

[0127] Please refer to the following: Figure 4 and Figure 11 Considering the installation of the sealing element 7, a thicker sealing element 7 might cause the pressure ring 5 to be pushed up, preventing an effective limiting connection with the limiting structure 6. Therefore, in some embodiments, when the limiting structure 6 is located in the first mounting groove 22 and protrudes from the bottom surface 22b of the groove, and the sealing element 7 is connected between the pressure ring 5 and the top cover plate 1, the pressure ring 5 compresses the sealing element 7. Along the axial direction of the first through hole 11, the compression amount of the sealing element 7 is d3, and the thickness of the limiting structure 6 is d1, where d1 > d3. It can be understood that the thickness of the sealing element 7 is D1, and the thickness of the sealed element 7 after compression is D2, where D1 - D2 = d3. In other words, when the pressure ring 5 is installed, the sealing element 7 can be compressed by the pressure ring 5. If the thickness of the limiting structure 6 is greater than the compressed thickness of the sealing element 7, the pressure ring 5 can form a connection with the limiting structure 6. Conversely, if the thickness of the limiting structure 6 is less than the compressed thickness of the seal 7, the seal 7 will still be relatively thick after compression, which may cause the pressure ring 5 to be pushed up, making it difficult for the pressure ring 5 to form a limiting connection with the limiting structure 6. In other words, when the thickness of the limiting structure 6 is greater than the compressed thickness of the seal 7, it is beneficial for the pressure ring 5 to form a limiting connection with the limiting structure 6, preventing the limiting structure 6 from failing to limit.

[0128] Please see also Figures 11 to 13 In some embodiments, the upper plastic 3 is engaged with at least one of the top cover plate 1, the pole post 4, and the pressure ring 5. Considering that the pressure ring 5 may twist and cause the pole post 4 to rotate, in order to further improve the anti-torsion effect of the pressure ring 5 and even the pole post 4, this application sets the upper plastic 3 to engage with the top cover plate 1, the pole post 4, and the pressure ring 5, so as to use the upper plastic 3 to limit the pole post 4 and the pressure ring 5, thereby preventing the rotation of the pressure ring 5 and the pole post 4.

[0129] In some examples, the upper plastic 3 can be snapped together with the top cover plate 1 alone, the upper plastic 3 can be snapped together with the pole post 4 alone, or the upper plastic 3 can be snapped together with the pressure ring 5 alone.

[0130] In other examples, the upper plastic 3 can be engaged with the top cover plate 1 and the pole post 4, or the upper plastic 3 can be engaged with the top cover plate 1 and the pressure ring 5, or the upper plastic 3 can be engaged with the pole post 4 and the pressure ring 5. That is, the upper plastic 3 is engaged with the two structures, which helps to form an interlock between the upper plastic 3 and any two of the top cover plate 1, the pole post 4, and the pressure ring 5, so that the upper plastic 3 has a better limiting effect on the top cover plate 1, the pole post 4, and the pressure ring 5, thereby further improving the restriction on the rotation of the pressure ring 5 and the pole post 4.

[0131] In some other examples, the upper plastic 3 can simultaneously engage with the top cover plate 1, the pole post 4, and the pressure ring 5. The upper plastic 3 can simultaneously lock the top cover plate 1, the pole post 4, and the pressure ring 5. Specifically, when the top cover plate 1 is installed in the energy storage device 100, the top cover plate 1 is fixed. Because the upper plastic 3 engages with the top cover plate 1, the position of the upper plastic 3 is fixed. Furthermore, because the upper plastic 3 engages with the pole post 4 and the pressure ring 5, the positions of the pressure ring 5 and the pole post 4 are also fixed. In this way, a layered engagement is formed, which helps to improve the stability of the upper plastic 3 in limiting the top cover plate 1, the pole post 4, and the pressure ring 5.

[0132] Please see also Figure 12 and Figure 13Optionally, when the upper plastic 3 is engaged with the top cover plate 1, the electrode post 4, and the pressure ring 5, the upper plastic 3 has a first engaging portion 31 on the side adjacent to the electrode post 4, and the electrode post 4 has a first mating portion 41 corresponding to the first engaging portion 31. One of the first engaging portion 31 and the first mating portion 41 is a first protrusion, and the other is a first recess. The upper plastic 3 has a second engaging portion 32 on the side adjacent to the top cover plate 1, and the top cover plate 1 has a second mating portion 13 corresponding to the second engaging portion 32. One of the second engaging portion 32 and the second mating portion 13 is a second protrusion, and the other is a second recess. The upper plastic 3 has a third engaging portion 33 on the side adjacent to the pressure ring 5, and the pressure ring 5 has a third mating portion 53 corresponding to the third engaging portion 33. One of the third engaging portion 33 and the third mating portion 53 is a third protrusion, and the other is a third recess. To ensure a better engagement between the upper plastic 3 and the top cover plate 1, the pole post 4, and the pressure ring 5, the upper plastic 3 employs a convex-concave fit with the top cover plate 1, the pole post 4, and the pressure ring 5. For example, in... Figure 13 In the example, the first locking part 31 is a first recess, the pole post 4 has a first mating part 41 that is a first protrusion, the second locking part 32 is a second protrusion, the second mating part 13 of the top cover plate 1 is a second recess, and when the third locking part 33 is a third protrusion, the third mating part 53 on the pressure ring 5 is a third recess. It can be seen that the mating connections between the upper plastic 3 and the top cover plate 1, the pole post 4, and the pressure ring 5 are all achieved through their own structures. When the upper plastic 3 is installed with the top cover plate 1, the pole post 4, and the pressure ring 5, a natural locking mechanism is formed, achieving effective locking between the upper plastic 3 and the top cover plate 1, the pole post 4, and the pressure ring 5 without additionally occupying the installation space of the top cover assembly 101.

[0133] Please see again Figure 11 Optionally, when the third snap-fit ​​portion 33 is a third protrusion, along the axial direction of the first through hole 11, the seal 7 of the top cover assembly 101 is located between the third snap-fit ​​portion 33 and the side wall of the second through hole 21. The thickness of the seal 7 is D1, and the thickness of the third snap-fit ​​portion 33 is d4, where D1 < d4. It is understood that when the pressure ring 5 is installed in the first mounting groove 22, the pressure ring 5 compresses the seal 7. To prevent the seal 7 from excessively deforming under the compression of the pressure ring 5 and thus protruding from the second mounting groove 12, the thickness of the third snap-fit ​​portion 33 of the upper plastic 3 can be greater than the thickness of the compressed part, thus preventing the deformed seal 7 from protruding. That is to say, in Figure 11In the example, after being compressed, the seal 7 can move in the space formed by the pressure ring 5, the third snap-fit ​​part 33, and the groove wall of the second mounting groove 12. Since the thickness of the third snap-fit ​​part 33 is relatively large, it blocks one side of the movement space of the seal 7. Above the groove wall of the second mounting groove 12, there is also the groove wall 22a of the first mounting groove, which blocks the other side of the movement space of the seal 7. The seal 7 is also blocked above by the pressure ring 5. In this way, the movement space of the seal 7 when it deforms is restricted, which helps to reduce the risk of the seal 7 being pushed out of the second mounting groove 12 when it is compressed by the pressure ring 5, and helps to improve the sealing effect of the seal 7.

[0134] Please see Figure 13 Optionally, the upper plastic 3 has a first side 3a and a second side 3b along the axial direction of the first through hole 11. A first snap-fit ​​portion 31 is provided on the first side 3a, and a second snap-fit ​​portion 32 and a third snap-fit ​​portion 33 are both provided on the second side 3b. Along the axial direction of the first through hole 11, the second snap-fit ​​portion 32 and the third snap-fit ​​portion 33 are staggered. The second snap-fit ​​portion 32 and the third snap-fit ​​portion 33 are provided on the same side to avoid possible interlocking interference between the second snap-fit ​​portion 32, the second mating portion 13, and the third snap-fit ​​portion 33. In some examples, in... Figure 13 In the example, when the second snap-fit ​​portion 32 and the third snap-fit ​​portion 33 are correspondingly provided on the upper plastic 3, their complete misalignment helps to prevent the second snap-fit ​​portion 32 from affecting the installation of the third snap-fit ​​portion 33 and the third mating portion 53, or to prevent the third snap-fit ​​portion 33 from affecting the installation of the second snap-fit ​​portion 32 and the second mating portion 13. Furthermore, the complete misalignment of the second snap-fit ​​portion 32 and the third snap-fit ​​portion 33 facilitates the alignment and installation of the upper plastic 3 with the top cover plate 1 and the pressure ring 5, respectively, and makes the positioning and installation of the upper plastic 3 easier.

[0135] In other examples, the second snap-fit ​​portion 32 and the third snap-fit ​​portion 33 may be partially misaligned. It is understood that since the second snap-fit ​​portion 32 and the third snap-fit ​​portion 33 are snapped with different structures respectively, the snap-fit ​​positions of the second snap-fit ​​portion 32 and the third snap-fit ​​portion 33 are located at different heights along the axial direction of the first through hole 11. In other words, the partial misalignment between the second snap-fit ​​portion 32 and the third snap-fit ​​portion 33 can also achieve effective snap-fit ​​without the second snap-fit ​​portion 32, the second mating portion 13, the third snap-fit ​​portion 33, and the third mating portion 53.

[0136] Secondly, please see Figure 14 This application also discloses an energy storage device 100, including a housing 102, a battery cell (not shown), and a top cover assembly 101 disclosed in the first aspect. The battery cell is disposed within the housing 102, and the top cover assembly 101 is configured to cover the housing 102.

[0137] When the top cover assembly 101 disclosed in the first aspect is disposed in the energy storage device 100, the outer peripheral surface 5a of the pressure ring of the top cover assembly 101 is spaced apart from the groove wall surface 22a of the first mounting groove of the lower plastic 2. This helps to reduce the heat melting of the lower plastic 2 and prevents the structure of the lower plastic 2 from being affected, which could lead to a decrease in the sealing performance of the top cover assembly 101 and cause electrolyte leakage in the energy storage device 100. Moreover, a limiting structure 6 is provided within the distance 22c between the outer peripheral surface 5a of the pressure ring and the groove wall surface 22a of the first mounting groove to restrict the pressure ring 5 from twisting at the distance 22c. This prevents the pressure ring 5 from twisting and causing a deterioration in the sealing effect between the pressure ring 5 and the lower plastic 2 and the electrode post 4, thus avoiding electrolyte leakage. In addition, to prevent the twisting of the pressure ring 5 from causing the electrode post 4 to rotate, this application also designs a snap-fit ​​structure for the upper plastic 3 to further prevent the pressure ring 5 and the electrode post 4 from twisting and causing a deterioration in the sealing effect of the top cover assembly 101.

[0138] It should be noted that current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, and consumption-side energy storage. The corresponding types of energy storage devices 100 include:

[0139] (1) Large-scale energy storage power stations applied to wind power and photovoltaic power stations can assist renewable energy power generation in meeting 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.

[0140] (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 realize peak shaving and valley filling of electricity load, that is, charging the energy storage battery when the electricity load is low and releasing the stored electricity during the peak electricity load period, thereby achieving a balance between power production and consumption.

[0141] Small-scale energy storage cabinets applied to the electricity consumption side primarily function to facilitate self-consumption of electricity, peak-valley price arbitrage, capacity cost management, and improve power supply reliability. Depending on the application scenario, electricity consumption-side energy storage can be categorized into commercial and industrial energy storage cabinets, residential energy storage devices, and energy storage charging piles, generally used in conjunction with distributed photovoltaic (PV) systems. Commercial and industrial users can utilize energy storage for peak-valley price arbitrage and capacity cost management. In electricity markets implementing peak-valley pricing, by charging the energy storage system 200 during low electricity prices and discharging it during high electricity prices, peak-valley price arbitrage can be achieved, reducing electricity costs. Furthermore, industrial enterprises subject to two-part tariffs can utilize the energy storage system 200 to store energy during off-peak hours and discharge it during peak load periods, thereby reducing peak power and the maximum declared demand, achieving the goal of reducing capacity charges. Residential PV systems with energy storage can improve the level of self-consumption of electricity. High electricity prices and poor power supply stability drive demand for residential PV installations. 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.

[0142] The number of energy storage devices 100 can be multiple, and the multiple energy storage devices 100 can be connected in series or in parallel. The multiple energy storage devices 100 are supported and electrically connected by an isolation plate (not shown). In this embodiment, "multiple" means two or more. An energy storage box can also be provided on the outside of the energy storage device 100 to house the energy storage device 100.

[0143] Optionally, the energy storage device 100 may include, but is not limited to, a single battery cell, a battery module, a battery pack, or a battery system. The actual application form of the energy storage device 100 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 energy storage device 100. This application embodiment only uses a multi-cell battery as an example for illustration. When the energy storage device 100 is a single battery cell, it may be at least one of cylindrical batteries, prismatic batteries, etc.

[0144] Thirdly, please see Figure 15 This application also discloses an energy storage system 200, including the energy storage device 100 disclosed in the second aspect.

[0145] In the energy storage system 200, the top cover assembly 101 of the energy storage device 100 can improve the heat melting of the lower plastic 2 by setting the distance 22c between the pressure ring 5 and the lower plastic 2, and prevent the pressure ring 5 and the electrode post 4 from twisting by the snap-fit ​​design of the limiting structure 6 and the upper plastic 3, thereby improving the leakage (electrolyte) problem of the energy storage device 100 that may be caused by the twisting of the pressure ring 5 and the electrode post 4.

[0146] To better understand the energy storage system 200 disclosed in this application, we will take a home energy storage scenario in user-side energy storage as an example for illustration. The energy storage device 100 of this application is not limited to home energy storage sites.

[0147] This application provides a residential energy storage system, which includes a power conversion device 201 (photovoltaic panel), a first user load 202 (streetlight), a second user load 203 (e.g., household appliances such as air conditioners), and an energy storage device 100. The energy storage device 100 is a small energy storage box that can be wall-mounted to an outdoor wall. Specifically, the photovoltaic panel can convert solar energy into electrical energy during periods of low electricity prices, and the energy storage device 100 is used to store this electrical energy and supply it to streetlights and household appliances during peak electricity prices, or to provide power during power outages / power failures.

[0148] The top cover assembly, energy storage device, and energy storage system disclosed in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the top cover assembly, energy storage device, and energy storage system of this application and their core ideas. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A top cover assembly, characterized in that, include: Top cover plate, wherein the top cover plate has a first through hole; The lower plastic is connected to the top cover plate. The lower plastic has a second through hole corresponding to the first through hole, and the second through hole is connected to the first through hole. The lower plastic has a first mounting groove on the side facing away from the top cover plate. The first mounting groove is arranged around the outer periphery of the second through hole. A pole post, wherein the pole post passes through the first through hole and the second through hole; The upper plastic is disposed on the outer periphery of the pole post and passes through the first through hole and the second through hole, and the upper plastic is connected to the top cover plate; A pressure ring, wherein the pressure ring is disposed in the first mounting groove, the pressure ring is connected to the pole post, and the outer peripheral surface of the pressure ring forms a gap with the groove wall surface of the first mounting groove; and A limiting structure is configured to restrict the pressure ring from rotating relative to the first mounting groove in the axial direction about the first through hole.

2. The top cover assembly according to claim 1, characterized in that, The limiting structure is formed within the spacing.

3. The top cover assembly according to claim 2, characterized in that, The limiting structure is located on the pressure ring, and / or the limiting structure is located in the first mounting groove.

4. The top cover assembly according to claim 3, characterized in that, The outer peripheral surface of the pressure ring is constructed as a non-circular surface. The limiting structure protrudes from the bottom surface of the first mounting groove and is close to or abuts against the outer peripheral surface of the pressure ring to restrict the axial rotation of the pressure ring relative to the first mounting groove around the first through hole.

5. The top cover assembly according to claim 4, characterized in that, The limiting structure is arranged around the outer circumference of the pressure ring, or, The outer peripheral surface of the pressure ring has multiple corners, and the limiting structure includes multiple limiting parts. The multiple limiting parts are spaced apart along the outer peripheral surface of the pressure ring, and each limiting part is respectively provided for each corner.

6. The top cover assembly according to claim 4, characterized in that, The limiting structure has an end face along the axial direction of the first through hole, the end face extending to connect with the bottom surface of the first mounting groove to form a first stepped surface, and the outer peripheral surface of the pressure ring forms a second stepped surface, the first stepped surface and the second stepped surface are connected in a mating manner.

7. The top cover assembly according to claim 6, characterized in that, The outer peripheral surface of the pressure ring is provided with a groove, and the inner wall surface of the groove is constructed as the second step surface. The limiting structure is at least partially located in the groove so that the first step surface approaches or abuts against the second step surface.

8. The top cover assembly according to claim 4, characterized in that, Along the radial direction of the first through hole, the side of the limiting structure opposite to the outer peripheral surface of the pressure ring is spaced apart from the groove wall surface of the first mounting groove.

9. The top cover assembly according to claim 4, characterized in that, Along the radial direction of the first through hole, the side of the limiting structure opposite to the outer peripheral surface of the pressure ring is connected to the groove wall of the first mounting groove.

10. The top cover assembly according to claim 3, characterized in that, The limiting structure includes a protrusion and a recess. One of the pressure ring and the first mounting groove is provided with the protrusion, and the other is provided with the recess. The protrusion is engaged with the recess.

11. The top cover assembly according to claim 10, characterized in that, The first mounting groove has two protrusions on its groove wall, and the two protrusions are spaced apart to form the recess. The outer peripheral surfaces of the protrusions and / or the protrusions are configured as arc surfaces.

12. The top cover assembly according to any one of claims 2-11, characterized in that, The limiting structure protrudes from the bottom surface of the first mounting groove along the axial direction of the first through hole. The thickness of the limiting structure is d1, and the thickness of the pressure ring is d2, wherein d1 < d2.

13. The top cover assembly according to any one of claims 1-11, characterized in that, The top cover plate is provided with a second mounting groove on the side facing the lower plastic, and the second mounting groove is arranged around the outer periphery of the first through hole; The top cover assembly also includes a sealing element, which is sleeved on the outer periphery of the upper plastic and located in the second mounting groove. Along the axial direction of the first through hole, the sealing element is connected between the pressure ring and the top cover plate.

14. The top cover assembly according to claim 13, characterized in that, The limiting structure is disposed in the first mounting groove and protrudes from the bottom surface of the first mounting groove. The sealing element is connected between the pressure ring and the top cover plate. The pressure ring compresses the sealing element along the axial direction of the first through hole. The compression amount of the sealing element is d3. The thickness of the limiting structure is d1, where d1 > d3. The thickness of the seal is D1, and the thickness of the seal after compression is D2, where D1-D2=d3.

15. The top cover assembly according to claim 1, characterized in that, The upper plastic part engages with at least one of the top cover plate, the pole post, and the pressure ring.

16. The top cover assembly according to claim 15, characterized in that, The upper plastic is engaged with the top cover plate, the pole post, and the pressure ring. The upper plastic has a first engaging part on the side near the pole post, and the pole post has a first mating part corresponding to the first engaging part. One of the first engaging part and the first mating part is a first protrusion, and the other is a first depression. The upper plastic is provided with a second snap-fit ​​part on the side near the top cover plate, and the top cover plate is provided with a second mating part corresponding to the second snap-fit ​​part. One of the second snap-fit ​​part and the second mating part is a second protrusion, and the other is a second recess. The upper plastic is provided with a third snap-fit ​​portion on the side near the pressure ring, and the pressure ring is provided with a third mating portion corresponding to the third snap-fit ​​portion. One of the third snap-fit ​​portion and the third mating portion is a third protrusion, and the other is a third recess.

17. The top cover assembly according to claim 16, characterized in that, The upper plastic has a first side and a second side along the axial direction of the first through hole. The first snap-fit ​​part is provided on the first side, and the second snap-fit ​​part and the third snap-fit ​​part are both provided on the second side. Along the axial direction of the first through hole, the second snap-fit ​​part and the third snap-fit ​​part are staggered.

18. The top cover assembly according to claim 16, characterized in that, The top cover assembly also includes a seal. When the third snap-fit ​​portion is a third protrusion, the seal is located between the third snap-fit ​​portion and the side wall of the second through hole along the axial direction of the first through hole. The thickness of the seal is D1, and the thickness of the third snap-fit ​​portion is d4, where D1 < d4.

19. An energy storage device, characterized in that, include: case; A battery cell, wherein the battery cell is disposed within the housing; as well as The top cover assembly according to any one of claims 1-18 is configured to cover the housing.

20. An energy storage system, characterized in that, Includes the energy storage device according to claim 19.

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