Lower plastic part, end cap assembly and energy storage device

Abstract

The application provides a lower plastic part, an end cover assembly and an energy storage device. The lower plastic part comprises a liquid leakage part having a first surface and a second surface arranged oppositely, the liquid leakage part comprising a plurality of first enclosing parts, a second enclosing part and a bottom part, the plurality of first enclosing parts and the second enclosing part being arranged on the same side of the bottom part, the plurality of first enclosing parts and the bottom part enclosing a first groove, the first groove penetrating the first surface, the surface of the bottom part away from the first enclosing part being the second surface, the second enclosing part being arranged around the outer periphery of the plurality of first enclosing parts, the first enclosing part, the second enclosing part and the bottom part enclosing a plurality of second grooves, the second grooves penetrating the first surface and communicating with the first groove; the liquid leakage part further comprising a plurality of liquid discharge holes, the liquid discharge holes penetrating the side wall of the second groove and the second surface respectively, the plurality of liquid discharge holes communicating with the plurality of second grooves; and a plastic body, the plastic body being arranged around the outer periphery of the second enclosing part and connected to one end of the second enclosing part away from the bottom part.

Description

Technical Field

[0001] This application relates to the field of electronics, specifically to a lower plastic part, an end cap assembly, and an energy storage device. Background Technology

[0002] In the battery cell manufacturing process, after the battery cell is injected with electrolyte, it is transported to the next process via a conveyor belt. At this time, the injection port on the lower plastic of the battery cell end cap is not sealed, and the conveyor belt transport process is subject to bumps and swaying. Most of the existing injection ports are straight-through designs. Therefore, during the transportation process before the injection port is sealed, the electrolyte is prone to overflow from the injection port, resulting in a reduction in the amount of electrolyte in the battery cell and a shortened cycle life. Secondly, it contaminates the explosion-proof valve patch and the terminal post of the battery cell, causing the battery cell to need to be reworked or scrapped. Furthermore, when sealing the injection port with sealing nails, the sealing nails are prone to fall into the battery cell, causing temporary sealing failure. The welding slag produced by the subsequent welding of the sealing aluminum nails is also prone to fall into the battery cell, causing a short circuit. Summary of the Invention

[0003] This application provides a lower plastic part that is applied to an energy storage device. When the energy storage device shakes or vibrates, it can better prevent the electrolyte inside the energy storage device from overflowing.

[0004] In a first aspect, embodiments of this application provide a lower plastic part, which includes:

[0005] A leakage section has a first surface and a second surface disposed opposite to each other. The leakage section includes multiple first enclosure portions, second enclosure portions, and a bottom. The multiple first enclosure portions and the second enclosure portions are disposed on the same side of the bottom. The multiple first enclosure portions are circumferentially spaced on the bottom, and the multiple first enclosure portions and the bottom form a first groove. The first groove penetrates the first surface. The surface of the bottom opposite to the first enclosure portions is the second surface. The second enclosure portions surround the outer periphery of the multiple first enclosure portions and are respectively connected to the multiple first enclosure portions and the bottom. The first enclosure portions, the second enclosure portions, and the bottom form multiple second grooves. The second grooves penetrate the first surface and communicate with the first grooves. The leakage section also has multiple drain holes. The drain holes respectively penetrate the sidewall of the second groove and the second surface. One drain hole communicates with one second groove, and different drain holes communicate with different second grooves.

[0006] A plastic body is provided around the outer periphery of the second enclosure portion and connected to one end of the second enclosure portion away from the bottom.

[0007] Furthermore, the drain hole has a first opening penetrating the sidewall of the second groove and a second opening penetrating the second surface. The first enclosure portion includes a first side portion, a second side portion, and a blocking portion. The multiple first sides portions of the multiple first enclosure portions and the bottom form a first groove. The second side portion and the blocking portion are both located on the side of the first side portion away from the first groove. The second side portion is bent and connected to the bottom, the first side portion, and the second enclosure portion respectively. The blocking portion is spaced apart from the bottom and forms the first opening. The blocking portion is bent and connected to the first side portion, the second side portion, and the second enclosure portion respectively. The second opening is located on the side of the blocking portion away from the first surface. The orthographic projection of the blocking portion on the second surface blocks the second opening.

[0008] Furthermore, the two adjacent first sides form a connecting channel that connects the first groove and the second groove, and the connecting channel is offset from the first opening.

[0009] Furthermore, on the orthographic projection of the leakage part onto the second surface, there is a hollow gap between the shielding part and the bottom, and the range of d1 of the hollow gap is 0.01mm≤d1≤0.08mm.

[0010] Furthermore, the total area s of the first openings of the plurality of drainage holes is in the range of 7mm. 2 ≤s≤14.2mm 2 .

[0011] Furthermore, the surface of the first side portion facing the second groove is a cylindrical arc surface, and the surface of the second enclosure portion facing the second groove is a cylindrical arc surface or a cylindrical surface. The cylindrical arc surface of the first side portion and the cylindrical arc surface or cylindrical surface of the second enclosure portion are coaxially arranged, and the second side portion extends radially along the cylindrical arc surface or the inner cylindrical surface.

[0012] Furthermore, along the circumferential direction of the first groove, the first side portions of the plurality of first enclosure portions all protrude or bend in a clockwise direction relative to the second side portions; or, along the circumferential direction of the first groove, the first side portions of the plurality of first enclosure portions all protrude or bend in a counterclockwise direction relative to the second side portions.

[0013] Furthermore, the bottom includes a first sub-part and a plurality of second sub-parts, the plurality of second sub-parts being spaced apart around the outer periphery of the first sub-part, the first sub-part and a plurality of first side portions forming the first groove, the second sub-parts forming part of the second groove, the surface of the second sub-part facing the second groove including an inclined surface, the inclined surface being located between the first opening and the communicating channel, the distance between the inclined surface and the second surface gradually increasing from the end closer to the first opening toward the end closer to the first opening of the communicating channel.

[0014] Furthermore, the inclined surface is a plane, and the angle α between the inclined surface and the second surface is in the range of 1°≤α≤60°.

[0015] Furthermore, the second opening has a fan-shaped structure, and the size of the second opening gradually decreases from one end near the second enclosure towards the side near the first groove.

[0016] Furthermore, there are two first enclosure portions, two second enclosure portions, and two second grooves and two second drainage holes; the first side portion has a first end and a second end disposed opposite to each other, and the second side portion is disposed close to the first end; the first enclosure portion also includes a third side portion, which is disposed at the second end and bent in a direction away from the first groove relative to the first side portion; the second side portion of one of the two first enclosure portions and the third side portion of the other are disposed facing each other to define the same second groove.

[0017] Furthermore, the surface of the shielding portion facing the second groove and close to the first opening is a third surface, and the third side portion has a fourth surface facing the drain hole and the second groove. The distance between the third surface and the fourth surface defining the same second groove gradually increases from the end close to the first groove toward the end away from the first groove.

[0018] Furthermore, the range of the angle β between the third surface and the fourth surface of the same second groove is defined as follows: 0 ≤ β ≤ 60°.

[0019] Furthermore, the leakage part also has multiple annular protrusions, which are disposed on the side of the bottom away from the first enclosure part. Each annular protrusion surrounds the outer periphery of a second opening, and different annular protrusions surround different second openings.

[0020] Furthermore, the height h1 of the annular boss is in the range of 0.1mm≤h1≤3mm.

[0021] Secondly, embodiments of this application also provide an end cap assembly, which includes:

[0022] Top cover, the top cover having a liquid injection hole; and

[0023] The lower plastic part described in this application embodiment is located on one side of the top cover. The plastic body is disposed closer to the top cover than the leakage part. The orthographic projection of the injection hole on the second surface at least partially overlaps with the orthographic projection of the first groove on the second surface.

[0024] Thirdly, embodiments of this application also provide an energy storage device, which includes:

[0025] The end cap assembly described in the embodiments of this application;

[0026] An adapter piece is disposed on the side of the lower plastic part opposite to the top cover, and one end of the adapter piece is electrically connected to the end cover assembly; and

[0027] An electrode assembly is disposed on the side of the adapter piece away from the end cap assembly, and the electrode assembly is electrically connected to the end of the adapter piece away from the end cap assembly.

[0028] The lower plastic part of this application embodiment includes a leakage part and a plastic body. The leakage part includes a plurality of first enclosure parts, a second enclosure part, and a bottom. The plurality of first enclosure parts and the bottom form a first groove. The first groove penetrates the first surface. The second enclosure parts are arranged around the outer periphery of the plurality of first enclosure parts. The first enclosure parts, the second enclosure parts, and the bottom form a plurality of second grooves. The second grooves penetrate the first surface and communicate with the first grooves. The leakage part also has a plurality of drainage holes. The drainage holes respectively penetrate the side wall of the second groove and the second surface. The drainage holes are arranged in a one-to-one correspondence with the second grooves. The lower plastic component of this application, by providing a bottom and a first enclosure, can prevent the electrolyte inside the energy storage device from sloshing back into the first groove when the device is shaken during assembly. This avoids electrolyte overflow from the first surface through the first groove, thus preventing a reduction in electrolyte and a decrease in cycle life. Furthermore, the bottom prevents the sealing nails of the end cap assembly from falling into the energy storage device, which could cause temporary sealing failure and allow weld slag from subsequent welding of the sealing nails to fall into the device, potentially causing a short circuit. Additionally, the drain hole penetrates the sidewall of the second groove. After the electrolyte enters the multiple drain holes from the first groove through multiple second grooves, it is dispersed in all directions, quickly dispersing the injected electrolyte to a greater distance and improving the uniformity of electrolyte wetting of the electrode components of the energy storage device. Furthermore, during electrolyte injection, the first and second surfaces do not directly penetrate each other in the direction of electrolyte injection. This prevents the high-speed injected electrolyte from directly impacting the electrode assembly below, causing the active material layer on the upper part of the electrode assembly to peel off and reducing the capacity of the energy storage device. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of 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.

[0030] Figure 1 This is a schematic diagram of the structure of the lower plastic part according to the first embodiment of this application.

[0031] Figure 2 This is a front view of the lower plastic part according to the first embodiment of this application.

[0032] Figure 3 The lower plastic part of the first embodiment of this application is along Figure 2 A schematic diagram of the cross-sectional structure along the AA direction.

[0033] Figure 4This is a structural schematic diagram of the lower plastic part according to the second embodiment of this application.

[0034] Figure 5 This is a front view of the lower plastic part according to the second embodiment of this application.

[0035] Figure 6 The lower plastic part of the second embodiment of this application is along Figure 5 Schematic diagram of the cross-sectional structure in the middle BB direction.

[0036] Figure 7 yes Figure 3 Enlarged view of the area within the dashed box I.

[0037] Figure 8 yes Figure 6 Enlarged view of the area within the dashed box II.

[0038] Figure 9 yes Figure 2 Enlarged view of area III within the dashed box.

[0039] Figure 10 yes Figure 5 Enlarged view of section IV within the dashed box.

[0040] Figure 11 This is a structural schematic diagram of the lower plastic part from another perspective of the first embodiment of this application.

[0041] Figure 12 This is a structural schematic diagram of the lower plastic part from another perspective of the second embodiment of this application.

[0042] Figure 13 This is a front perspective view of the lower plastic part according to the first embodiment of this application.

[0043] Figure 14 This is a schematic diagram of the structure of an end cap assembly according to an embodiment of this application.

[0044] Figure 15 This is an exploded structural diagram of an end cap assembly according to an embodiment of this application.

[0045] Figure 16 This is a schematic diagram of the structure of an end cap assembly according to another embodiment of this application.

[0046] Figure 17 This is an exploded structural diagram of an end cap assembly according to another embodiment of this application.

[0047] Figure 18 This is a schematic diagram of the structure of an energy storage device according to an embodiment of this application.

[0048] Figure 19 This application describes an energy storage device along... Figure 18 A schematic diagram of the cross-sectional structure along the CC direction.

[0049] Explanation of reference numerals in the attached figures:

[0050] 100 - Lower plastic part, 10 - Drainage part, 101 - First surface, 102 - Second surface, 103 - First groove, 104 - Second groove, 105 - Drainage hole, 105a - First opening, 105b - Second opening, 106 - Connecting channel, 107 - Hollowed-out gap, 108 - Third surface, 109 - Fourth surface, 11 - First enclosure part, 111 - First side part, 1111 - First end, 1112 - Second end, 112 - Second side part, 113 - Covering part, 114 - Third side part, 12 - Second enclosure part, 13 - Bottom, 131 - First sub-part, 132 - Second Sub-parts, 1321-inclined surface, 14-annular boss, 20-plastic body, 30-vent hole, 200-end cap assembly, 210-top cap, 211-liquid injection hole, 212-explosion-proof hole, 220-explosion-proof component, 221-explosion-proof sheet, 222-protective sheet, 230-positive electrode metal block, 240-positive electrode post, 250-negative electrode metal block, 260-negative electrode post, 270-upper plastic part, 280-sealing nail, 300-energy storage device, 310-electrode assembly, 311-positive electrode sheet, 312-diaphragm, 313-negative electrode sheet, 320-shell, 321-receiving cavity. Detailed Implementation

[0051] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0052] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0053] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0054] It should be noted that, for ease of explanation, the same reference numerals denote the same components in the embodiments of this application, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0055] In the battery cell manufacturing process, after the battery cell is injected with electrolyte, it is transported to the next process via a conveyor belt. At this time, the injection port on the lower plastic of the battery cell end cap is not sealed, and the conveyor belt transport process is subject to bumps and swaying. Most of the existing injection ports are straight-through designs. Therefore, during the transportation process before the injection port is sealed, the electrolyte is prone to overflow from the injection port, resulting in a reduction in the amount of electrolyte in the battery cell and a shortened cycle life. Secondly, it contaminates the explosion-proof valve patch and the terminal post of the battery cell, causing the battery cell to need to be reworked or scrapped. Furthermore, when sealing the injection port with sealing nails, the sealing nails are prone to fall into the battery cell, causing temporary sealing failure. The welding slag produced by the subsequent welding of the sealing aluminum nails is also prone to fall into the battery cell, causing a short circuit.

[0056] Please see Figures 1 to 6 This application provides a lower plastic part 100, which includes a leakage portion 10 and a plastic body 20. The leakage portion 10 has a first surface 101 and a second surface 102 disposed opposite to each other. The leakage portion 10 includes a plurality of first blocking portions 11, second blocking portions 12, and a bottom 13. The plurality of first blocking portions 11 and second blocking portions 12 are disposed on the same side of the bottom 13. The plurality of first blocking portions 11 are circumferentially spaced on the bottom 13. The plurality of first blocking portions 11 and the bottom 13 form a first groove 103. The first groove 103 penetrates the first surface 101. The surface of the bottom 13 opposite to the first blocking portions 11 is the... The second surface 102, the second enclosure portion 12 is arranged around the outer periphery of the plurality of first enclosure portions 11 and respectively connects the plurality of first enclosure portions 11 and the bottom 13, the first enclosure portions 11, the second enclosure portions 12 and the bottom 13 form a plurality of second grooves 104, the second grooves 104 penetrate the first surface 101 and communicate with the first grooves 103; the liquid leakage portion 10 also has a plurality of drain holes 105, the drain holes 105 respectively penetrate the side wall of the second groove 104 and the second surface 102, one drain hole 105 communicates with one second groove 104, and different drain holes 105 communicate with different second grooves 104.

[0057] The term "multiple" refers to two or more, such as, but not limited to, two, three, four, five, six, etc.

[0058] The lower plastic part 100 of this application is applied to the end cap assembly of an energy storage device (e.g., a battery). When the lower plastic part 100 is applied to the end cap assembly, the plastic body 20 is closer to the outer surface of the end cap assembly than the leakage portion 10; in other words, the leakage portion 10 is closer to the interior of the energy storage device than the plastic body 20.

[0059] Optionally, the leakage part 10 and the plastic body 20 are an integral structure, the leakage part 10 and the plastic body 20 are different parts of the same component, and the leakage part 10 and the plastic body 20 can be formed by an integral injection molding process.

[0060] Understandably, both the first groove 103 and the second groove 104 penetrate the second surface 102.

[0061] Understandably, the number of drainage holes 105 corresponds one-to-one with the number of second grooves 104.

[0062] Understandably, the drain hole 105 is located between the first enclosure portion 11 and the second enclosure portion 12.

[0063] Understandably, a plurality of first enclosure portions 11 are spaced apart around the inner peripheral sidewall of the second enclosure portion 12.

[0064] It should be noted that a plurality of first enclosure portions 11 are arranged circumferentially at intervals on the bottom 13. It can be understood that the plurality of first enclosure portions 11 are arranged circumferentially at intervals along the bottom 13.

[0065] It should be noted that the plastic body 20 and the bottom 13 are spaced apart along the arrangement direction of the first surface 101 and the second surface 102, and the plastic body 20 is disposed close to the first surface 101. In some embodiments, the surface of the plastic body 20 facing away from the second surface 102 is disposed on the same side as the first surface 101.

[0066] It should be noted that when the plastic part 100 is applied to the end cap assembly of the energy storage device, the first surface 101 is closer to the outer surface of the end cap assembly than the second surface 102.

[0067] When the plastic part 100 is applied to the energy storage device, the electrolyte enters from outside the energy storage device, flows through the first groove 103, the second groove 104 and the drain hole 105 in sequence, and enters the interior of the energy storage device.

[0068] Understandably, the plurality of drainage holes 105 are spaced apart around the outer periphery of the bottom 13.

[0069] Understandably, each second groove 104 forms a “Z”-shaped channel with a drain hole 105.

[0070] The lower plastic part 100 of this application embodiment includes a leakage part 10 and a plastic body 20. The leakage part 10 includes a plurality of first blocking parts 11, second blocking parts 12 and a bottom 13. The plurality of first blocking parts 11 and the bottom 13 form a first groove 103. The first groove 103 penetrates the first surface 101. The second blocking parts 12 are arranged around the outer periphery of the plurality of first blocking parts 11. The first blocking parts 11, the second blocking parts 12 and the bottom 13 form a plurality of second grooves 104. The second grooves 104 penetrate the first surface 101 and communicate with the first grooves 103. The leakage part 10 also has a plurality of drain holes 105. The drain holes 105 respectively penetrate the side wall of the second groove 104 and the second surface 102. The drain holes 105 and the second grooves 104 are arranged in a one-to-one correspondence. The lower plastic component 100 of this application, by providing a bottom 13 and a first enclosure 11, can prevent the electrolyte in the energy storage device from sloshing back into the first groove 103 when the lower plastic component 100 is applied to the energy storage device and shakes during the assembly process. This avoids the electrolyte overflowing from the first surface 101 through the first groove 103, thus preventing a reduction in electrolyte in the energy storage device and a decrease in cycle life. In addition, the bottom 13 can also prevent the sealing nails of the end cap assembly from falling into the energy storage device, which could cause a temporary sealing failure. Weld slag generated from the subsequent welding of the sealing aluminum nails could easily fall into the energy storage device, causing a short circuit. Furthermore, the drain hole 105 penetrates the side wall of the second groove 104. After the electrolyte enters the multiple drain holes 105 from the first groove 103 through multiple second grooves 104, the electrolyte is sprayed in all directions, which can quickly disperse the injected electrolyte to a greater distance and improve the uniformity of electrolyte wetting of the electrode components of the energy storage device. Furthermore, during electrolyte injection, the first surface 101 and the second surface 102 do not directly penetrate each other in the direction of electrolyte injection, thus preventing the high-speed injected electrolyte from directly impacting the electrode assembly below, causing the active material layer on the upper end of the electrode assembly to peel off and reducing the capacity of the energy storage device.

[0071] Please see also Figure 7 and Figure 8In some embodiments, the drain hole 105 has a first opening 105a penetrating the sidewall of the second groove 104 and a second opening 105b penetrating the second surface 102. The first enclosure portion 11 includes a first side portion 111, a second side portion 112, and a blocking portion 113. The plurality of first side portions 111 of the plurality of first enclosure portions 11 and the bottom 13 form a first groove 103. The second side portion 112 and the blocking portion 113 are both located on the side of the first side portion 111 opposite to the first groove 103. The two side portions 112 are respectively bent and connected to the bottom 13, the first side portion 111 and the second enclosure portion 12. The shielding portion 113 is spaced apart from the bottom 13 and surrounds the first opening 105a. The shielding portion 113 is respectively bent and connected to the first side portion 111, the second side portion 112 and the second enclosure portion 12. The second opening 105b is located on the side of the shielding portion 113 away from the first surface 101. The orthographic projection of the shielding portion 113 on the second surface 102 shields the second opening 105b.

[0072] It should be noted that when the orthographic projection of the shielding portion 113 on the second surface 102 completely blocks the second opening 105b, and even the bottom 13 of the shielding portion 113, this can better prevent the electrolyte from overflowing. However, it will increase the difficulty of manufacturing the lower plastic part 100. Therefore, in order to make the lower plastic part 100 have lower manufacturing costs and better anti-overflow and anti-backflow effects, the orthographic projection of the shielding portion 113 on the second surface 102 can exactly cover the second opening 105b. The orthographic projection of the shielding portion 113 on the second surface 102 can also cover most of the second opening 105b, for example, so that the second opening 105b is covered or blocked by more than 80%, specifically more than or equal to 85%, more than or equal to 88%, more than or equal to 90%, more than or equal to 93%, more than or equal to 98%, etc.

[0073] Understandably, the second side portion 112 and the blocking portion 113 are both located between the first side portion 111 and the second enclosure portion 12.

[0074] Understandably, the plane containing the first opening 105a intersects the first surface 101. In one specific embodiment, the plane containing the first opening 105a is perpendicular to the first surface 101 and perpendicular to the plane containing the second opening 105b (i.e., the second surface 102), and the first surface 101 is parallel to the second surface 102.

[0075] Understandably, the drain hole 105 is located between the first side portion 111 and the second enclosure portion 12; both the first opening 105a and the second opening 105b are located between the first side portion 111 and the second enclosure portion 12.

[0076] In some embodiments, along the arrangement direction of the first surface 101 and the second surface 102, the blocking portion 113 is located between the bottom 13 and the plastic body 20, such as... Figure 3 and Figure 7 As shown.

[0077] In other embodiments, along the arrangement direction of the first surface 101 and the second surface 102, the blocking portion 113 is flush with the plastic body 20, such as... Figure 6 and Figure 8 As shown. Understandably, in this embodiment, the shielding portion 113 is away from the surface of the bottom 13, the plastic body 20 is away from the surface of the bottom 13, and the first surface 101 are all coplanar.

[0078] In this embodiment, the second opening 105b is blocked by the orthogonal projection of the shielding part 113 on the second surface 102. When the plastic part 100 is applied to the energy storage device and the energy storage device shakes during assembly, the upward-rushing electrolyte can not only be blocked by the bottom 13, but the electrolyte entering the second opening 105b can also be blocked by the shielding part 113. Even if a small amount of electrolyte enters the second groove 104 through the drain hole 105, it will flow back into the energy storage device, thereby better preventing the electrolyte inside the energy storage device from overflowing when it shakes.

[0079] Please see again Figure 2 and Figure 5 In some embodiments, two adjacent first sides 111 form a connecting channel 106 that connects the first groove 103 and the second groove 104, and the connecting channel 106 is offset from the first opening 105a.

[0080] Understandably, the first opening 105a is located at a position away from the connecting channel 106.

[0081] Understandably, the drain hole 105, the second groove 104, and the connecting channel 106 are provided in a one-to-one correspondence. In a specific embodiment, the number of the first groove 103 is one, and the number of the second groove 104, the connecting channel 106, and the drain hole 105 are all four (e.g., Figure 2 (As shown). In another specific embodiment, the number of the first groove 103 is one, and the number of the second groove 104, the communicating channel 106, and the drain hole 105 are all two (as shown). Figure 5 (As shown).

[0082] When the lower plastic part 100 is applied to the energy storage device and electrolyte is injected, the electrolyte enters from the first groove 103 and flows sequentially through the connecting channel 106, the second groove 104, the first opening 105a and the second opening 105b into the interior of the energy storage device.

[0083] In this embodiment, by staggering the first opening 105a from the connecting channel 106, when the lower plastic part 100 is applied to the energy storage device and the energy storage device shakes during assembly, when the electrolyte overflows from the drain hole 105 through the second opening 105b, the electrolyte entering the drain hole 105 can be blocked back by the shielding part 113. On the other hand, since the first opening 105a and the connecting channel 106 are staggered, even if a small amount of electrolyte enters the second groove 104, the electrolyte will be blocked by the first side part 111 and flow back into the energy storage device, making it difficult for it to cross the second groove 104 and enter the first groove 103 through the connecting channel 106. It can also be understood that by increasing the path between the first opening 105a and the connecting channel 106, the probability of electrolyte overflow when the energy storage device shakes is reduced.

[0084] Please see again Figures 1 to 3 In some embodiments, the first side 111 of one of two adjacent first enclosure portions 11, the two second sides 112 of the two connected first enclosure portions 11, the bottom 13, and the second enclosure portion 12 define the second groove 104.

[0085] Please see Figure 9 and Figure 10 In some embodiments, the leakage part 10 is projected onto the second surface 102, and the shielding part 113 and the bottom 13 have a hollow gap 107, the width d1 of the hollow gap 107 being in the range of 0.01mm≤d1≤0.08mm.

[0086] Understandably, the perforated gap 107 is formed because the shielding part 113 completely blocks the second opening 105b.

[0087] Understandably, the distance between the sidewall of the bottom 13 facing the drain hole 105 and close to the second groove 104 and the sidewall of the shielding portion 113 facing the second groove 104 ranges from 0.01 mm to 0.08 mm.

[0088] Specifically, the width d1 of the hollowed-out gap 107 can be, but is not limited to, 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, etc.

[0089] The lower plastic part 100 of this embodiment can be manufactured by injection molding using an injection mold. The injection mold includes an upper mold and a lower mold, which together form a mold cavity. A first protrusion needs to be provided on the surface of the upper mold facing the mold cavity at the position corresponding to the first groove 103, the connecting channel 106, and the second groove 104. A second protrusion needs to be provided on the surface of the lower mold facing the mold cavity at the position corresponding to the second opening 105b. The first protrusion and the second protrusion should be arranged as close as possible to each other. After injection molding, a first opening 105a can be formed between the first protrusion and the second protrusion. The entire lower plastic part 100 can be integrally injection molded without the need for sliders, which have high demolding difficulty and high cost. This greatly reduces the manufacturing cost of the injection mold, thereby reducing the manufacturing cost of the lower plastic part 100.

[0090] In this embodiment, if the width d1 of the hollowed-out gap 107 is too small, when the lower plastic part 100 is injection molded, the first protrusion forming the first groove 103, the connecting channel 106, and the second groove 104 will abut against the second protrusion forming the drain hole 105. This may even cause the first protrusion to be partially embedded in the first opening 105a after the injection molding is complete, thereby affecting the demolding of the lower plastic part 100 and increasing the difficulty of manufacturing the lower plastic part 100. If the width d1 of the hollowed-out gap 107 is too large, the shielding effect of the shielding part 113 on the second opening 105b will be reduced, and the electrolyte cannot be effectively prevented from entering the drain hole 105 from the second opening 105b, passing through the second groove 104, the connecting channel 106, and the first groove 103, and finally flowing to the side of the first surface 101 away from the second surface 102, thereby overflowing outside the energy storage device.

[0091] In some embodiments, the total area s of the first opening 105a of the plurality of drainage holes 105 is in the range of 7 mm. 2 ≤s≤14.2mm 2 .

[0092] Specifically, the total area s of the first opening 105a of the plurality of drainage holes 105 can be, but is not limited to, 7 mm. 2 8mm 2 9mm 2 10mm 2 11mm 2 12mm 2 13mm 2 14mm 2 14.2mm 2 wait.

[0093] In this embodiment, if the total area s of the first openings 105a of the plurality of drain holes 105 is too small, the electrolyte flow rate will be too slow when the lower plastic part 100 is applied to the energy storage device and injected with electrolyte, affecting the injection efficiency. Furthermore, it will easily cause electrolyte splashing during injection, spilling out of the energy storage device. If the total area s of the first openings 105a of the plurality of drain holes 105 is too large, the electrolyte will easily pass through the drain holes 105 during the vibration of the lower plastic part 100, causing overflow and reducing the anti-overflow and anti-backflow effect of the lower plastic part 100 when the energy storage device shakes. When the area s1 of the first opening 105a is in the range of 0.5mm ≤ s1 ≤ 3mm, the energy storage device can have a higher injection rate while also having better anti-backflow and anti-overflow effects when the lower plastic part 100 is applied to the energy storage device.

[0094] Please see again Figure 2 and Figure 5 In some embodiments, the surface of the first side portion 111 facing the second groove 104 is a cylindrical arc surface, and the surface of the second enclosure portion 12 facing the second groove 104 is a cylindrical arc surface or a cylindrical surface. The cylindrical arc surface of the first side portion 111 and the cylindrical arc surface or cylindrical surface of the second enclosure portion 12 are coaxially arranged, and the second side portion 112 extends radially along the cylindrical arc surface or the inner cylindrical surface.

[0095] In one specific embodiment, the surface of the first side portion 111 facing the second groove 104 is a cylindrical arc surface, and the surface of the second enclosure portion 12 facing the second groove 104 is also a cylindrical arc surface. The cylindrical arc surface of the first side portion 111 and the cylindrical arc surface of the second enclosure portion 12 are coaxially arranged, and the second side portion 112 extends radially along the cylindrical arc surface. In other words, the orthographic projection of the cylindrical arc surface of the first side portion 111 onto the second surface 102 and the orthographic projection of the cylindrical arc surface of the second enclosure portion 12 onto the second surface 102 are concentric arcs.

[0096] In another specific embodiment, the surface of the first side portion 111 facing the second groove 104 is a cylindrical arc surface, and the surface of the second enclosure portion 12 facing the second groove 104 is a cylindrical surface. The cylindrical arc surface of the first side portion 111 and the cylindrical surface of the second enclosure portion 12 are coaxially arranged, and the second side portion 112 extends radially along the cylindrical arc surface. In other words, the orthographic projection of the cylindrical arc surface of the first side portion 111 onto the second surface 102 is concentric with the orthographic projection of the cylindrical surface of the second enclosure portion 12 onto the second surface 102.

[0097] In this embodiment, by coaxially fitting the surface of the first side portion 111 facing the second groove 104 with the surface of the second enclosure portion 12 facing the second groove 104, the width of the second groove 104 formed by the surface of the first side portion 111 facing the second groove 104 and the surface of the second enclosure portion 12 facing the second groove 104 is equal along the flow path of the electrolyte. This allows the electrolyte to flow more evenly into the energy storage device during injection, avoiding electrolyte splashing that could affect the injection speed due to unstable channel dimensions.

[0098] In some embodiments, along the circumferential direction of the first groove 103, the first side portions 111 of the plurality of first blocking portions 11 all protrude or bend in a clockwise direction relative to the second side portions 112; or, along the circumferential direction of the first groove 103, the first side portions 111 of the plurality of first blocking portions 11 all protrude or bend in a counterclockwise direction relative to the second side portions 112.

[0099] Understandably, along the circumferential direction of the first groove 103, the first side portions 111 of the plurality of first enclosure portions 11 all protrude or bend in a clockwise direction relative to the first opening 105a, or, along the circumferential direction of the first groove 103, the first side portions 111 of the plurality of first enclosure portions 11 all protrude or bend in a counterclockwise direction relative to the first opening 105a.

[0100] In one specific embodiment, there are four first enclosure portions 11. The first side portion 111 of each first enclosure portion 11 is bent in a counterclockwise direction relative to the second side portion 112 to form a counterclockwise spiral structure. When the electrolyte enters the first groove 103, it enters the multiple second grooves 104 through multiple connecting channels 106, and then rotates clockwise along the multiple second grooves 104, passes through multiple first openings 105a and drain holes 105, and finally enters the energy storage device.

[0101] It should be noted that when the first side portion 111 of the plurality of first enclosure portions 11 protrudes or bends in a clockwise direction relative to the second side portion 112, the electrolyte flows into the first opening 105a of the plurality of drain holes 105 in a counterclockwise direction; when the first side portion 111 of the plurality of first enclosure portions 11 protrudes or bends in a counterclockwise direction relative to the second side portion 112, the electrolyte flows into the first opening 105a of the plurality of drain holes 105 in a clockwise direction, thereby forming a reverse labyrinth of electrolyte.

[0102] In this embodiment, by making the first side portion 111 of the plurality of first enclosure portions 11 protrude or bend in a clockwise direction relative to the second side portion 112, or by making the first side portion 111 of the plurality of first enclosure portions 11 protrude or bend in a counterclockwise direction relative to the second side portion 112 along the circumferential direction of the first groove 103, the electrolyte can form multiple spiral jet electrolyte flows when it enters the side of the lower plastic part 100 facing the energy storage device through the plurality of drain holes 105. This allows the electrolyte to be dispersed more quickly and further away, and better dispersed to various positions of the electrode assembly (including the positive electrode and the negative electrode), improving the uniformity of the electrode assembly wetting. In addition, it can also prevent the electrolyte from directly impacting the upper end of the electrode assembly, causing the tabs on the top of the electrode assembly to fold over and short-circuit between the positive and negative electrodes, resulting in an internal short circuit.

[0103] Please see also Figure 7 , Figure 11 and Figure 12 In some embodiments, the bottom 13 includes a first sub-part 131 and a plurality of second sub-parts 132, the plurality of second sub-parts 132 being spaced apart around the outer periphery of the first sub-part 131. The first sub-part 131 and a plurality of first side parts 111 form a first groove 103, and the second sub-parts 132 form a part of a second groove 104. The surface of the second sub-part 132 facing the second groove 104 includes an inclined surface 1321, the inclined surface 1321 being located between the first opening 105a and the communicating channel 106. The distance between the inclined surface 1321 and the second surface 102 gradually increases from the end near the first opening 105a toward the end near the first opening 105a of the communicating channel 106.

[0104] Understandably, the second sub-part 132 is located within the second groove 104. The inclined surface 1321 is located within the second groove 104.

[0105] Understandably, the plurality of first enclosure portions 11, the plurality of second sub-portions 132 and the second enclosure portions 12 enclose the plurality of second grooves 104.

[0106] In one specific embodiment, there are four second sub-parts 132, which are evenly distributed along the outer periphery of the first sub-part 131.

[0107] Optionally, one end of the inclined surface 1321 is connected to the second sub-part 132 to form the sidewall of the first opening 105a.

[0108] Understandably, the first opening 105a is formed by the first side portion 111, the second sub-part 132, the shielding portion 113 and the second enclosure portion 12, and the second opening 105b penetrates the second sub-part 132.

[0109] In this embodiment, by setting the inclined surface 1321, when the lower plastic part 100 is applied to the energy storage device, and the energy storage device is injecting electrolyte, after the electrolyte enters the second groove 104, the inclined surface 1321 can accelerate the flow speed of the electrolyte and improve the electrolyte injection efficiency. In addition, before the injection port is sealed after the injection is completed, when the energy storage device is shaken during transmission, if electrolyte flows back into the second groove 104, the electrolyte will flow downward along the inclined surface 1321 under the action of gravity. The downward flowing electrolyte and the upward flowing electrolyte form a counterflow, reducing the potential energy of the upward flowing electrolyte and preventing a large amount of electrolyte from flowing back into the second groove 104 and then into the first groove 103, increasing the difficulty for the upward flowing electrolyte to enter the second groove 104. This makes the lower plastic part 100 have better anti-backflow and anti-overflow effects.

[0110] Please see again Figure 7 In some embodiments, the inclined surface 1321 is a plane, and the angle α between the inclined surface 1321 and the second surface 102 is in the range of 1°≤α≤60°.

[0111] It should be noted that in other embodiments, the inclined surface 1321 may also be non-planar, such as a smoothly transitioned curved surface, as long as the distance between the inclined surface 1321 and the second surface 102 gradually increases from the end near the first opening 105a toward the end near the first opening 105a of the connecting channel 106.

[0112] Specifically, the angle α between the inclined surface 1321 and the second surface 102 can be, but is not limited to, 1°, 3°, 5°, 8°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, etc.

[0113] In this embodiment, if the angle α between the inclined surface 1321 and the second surface 102 is too small, the slope of the inclined surface 1321 is too small, and the increase in the anti-backflow and anti-overflow effect is not significant. If the angle α between the inclined surface 1321 and the second surface 102 is too large, the length of the inclined surface 1321 along the electrolyte flow path is too small, and similarly, the increase in the anti-backflow and anti-overflow effect is not significant. When the angle α between the inclined surface 1321 and the second surface 102 is in the range of 1°≤α≤60°, the lower plastic part 100 has a better anti-backflow and anti-overflow effect.

[0114] Furthermore, the inclined surface 1321 is a plane, and the angle α between the inclined surface 1321 and the second surface 102 is in the range of 10°≤α≤55°. This allows the lower plastic part 100 to have better anti-backflow and anti-overflow effects.

[0115] Please see again Figure 11 In some embodiments, the second opening 105b has a fan-shaped structure, and the size of the second opening 105b gradually decreases from one end near the second enclosure portion 12 toward the side near the first groove 103.

[0116] In one specific embodiment, four fan-shaped second openings 105b are symmetrically distributed along the circumference of the bottom 13.

[0117] In this embodiment, by making the second opening 105b a fan-shaped structure, the amount of electrolyte splashed back into the second opening 105b in the energy storage device can be better reduced, thereby giving the lower plastic part 100 a better anti-backflow and anti-overflow effect.

[0118] Please see Figure 13 In some embodiments, there are two first enclosure portions 11, two second enclosure portions 12, and two second grooves 104 and two second drainage holes 105; the first side portion 111 has a first end 1111 and a second end 1112 disposed opposite to each other, and the second side portion 112 is disposed close to the first end 1111; the first enclosure portion 11 further includes a third side portion 114, which is disposed at the second end 1112 and bent in a direction away from the first groove 103 relative to the first side portion 111; the second side portion 112 of one of the two first enclosure portions 11 and the third side portion 114 of the other are disposed facing each other to define the same second groove 104.

[0119] Understandably, the two first enclosure portions 11 are spaced apart and arranged opposite each other, and the two first enclosure portions 11 are arranged in opposite directions, such that the second side portion 112 of one of them and the third side portion 114 of the other are located on the same side of the first groove 103; the third side portion 114 of one of them and the second side portion 112 of the other are both located on the other side of the first groove 103.

[0120] Understandably, the first end 1111 is positioned closer to the second side 112 than the second end 1112.

[0121] Understandably, the third side 114 is bent and connected to the first side 111, and bends in a direction away from the first groove 103.

[0122] It is also understandable that the third side 114 is spaced apart from the second side 112, and the third side 114 is spaced apart from the shielding part 113.

[0123] Understandably, the two second enclosure portions 12 are spaced apart and arranged opposite to each other, and the arrangement direction of the two second enclosure portions 12 intersects with the arrangement direction of the two second enclosure portions 12. In a specific embodiment, the arrangement direction of the two second enclosure portions 12 is perpendicular to the arrangement direction of the two second enclosure portions 12.

[0124] It should be noted that the third side portion 114 is positioned facing the first opening 105a, or the third side portion 114 is positioned opposite to the first opening 105a.

[0125] It should be noted that one end of the third side 114 is connected to the first side 111, and the other end is connected to the second enclosure 12. In this embodiment, the second enclosure 12, the third side 114, the first side 111, the second side 112, another second enclosure 12, another third side 114, another first side 111, and another second side 112 are connected end to end in sequence to form a bow tie-like shape, that is, the arrangement of the two second grooves 104 and the first groove 103 is similar to the bow tie shape.

[0126] In this embodiment, by providing the third side portion 114, even if the energy storage device shakes and some electrolyte flows from the drain hole 105 into the second groove 104, it will not change direction due to kinetic energy and enter the connecting channel 106 and the first groove 103. Instead, it will be blocked or bounced back by the third side portion 114 and flow back to the drain hole 105 to re-enter the energy storage device. This greatly increases the difficulty of electrolyte backflow or overflow, thereby improving the anti-backflow and anti-overflow effect of the lower plastic part 100.

[0127] Please see again Figure 13 In some embodiments, the surface of the shielding portion 113 facing the second groove 104 and close to the first opening 105a is a third surface 108, and the third side portion 114 has a fourth surface 109 facing the drain hole 105 and the second groove 104. The distance between the third surface 108 and the fourth surface 109 defining the same second groove 104 gradually increases from the end close to the first groove 103 toward the end away from the first groove 103.

[0128] In this embodiment, by making the distance between the third surface 108 and the fourth surface 109 defining the same second groove 104 gradually increase from the end near the first groove 103 toward the end away from the first groove 103, the electrolyte flowing back into the second groove 104 can be blocked by the third side 114, which can better prevent the backflowing electrolyte from flowing back into the drain hole 105, and better prevent the third side 114 from splashing some of the backflowing electrolyte back into the first groove 103, greatly increasing the difficulty of electrolyte backflow or overflow.

[0129] Optionally, the angle β between the third surface 108 and the fourth surface 109 of the same second groove 104 is defined as an acute angle. This allows the third side 114 to better block the backflowing electrolyte back to the drain hole 105, rather than splashing it back into the first groove 103, greatly increasing the difficulty of electrolyte backflow or overflow.

[0130] In some embodiments, the angle β between the third surface 108 and the fourth surface 109 of the same second groove 104 is defined as follows: 0°≤β≤60°.

[0131] Specifically, the angle β between the third surface 108 and the fourth surface 109 of the same second groove 104 can be, but is not limited to, 0°, 1°, 3°, 5°, 8°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, etc.

[0132] In this embodiment, if the angle β between the third surface 108 and the fourth surface 109 of the same second groove 104 is too small, the effect of the third side portion 114 in blocking the backflowing electrolyte back to the drain hole 105 is reduced. If the angle β between the third surface 108 and the fourth surface 109 of the same second groove 104 is too large, the angle between the third side portion 114 and the second enclosure portion 12 is too small, which increases the difficulty and cost of manufacturing the lower plastic part 100. In addition, if the angle between the third side portion 114 and the second enclosure portion 12 is too small, the backflowing electrolyte is more likely to remain in the gap between the third side portion 114 and the second enclosure portion 12, reducing the service life of the energy storage device. In this embodiment, when the angle β between the third surface 108 and the fourth surface 109 of the same second groove 104 is limited to the range of 0°≤β≤60°, the lower plastic part 100 can have better anti-backflow and anti-overflow effects, and the lower plastic part 100 can have a more suitable manufacturing cost. It can also prevent backflowing electrolyte residue from remaining in the gap between the third side 114 and the second enclosure 12, thus reducing the service life of the energy storage device.

[0133] Furthermore, the angle β between the third surface 108 and the fourth surface 109 of the same second groove 104 is limited to a range of 5° ≤ β ≤ 50°. This allows the lower plastic part 100 to have better anti-backflow and anti-overflow effects, while also making the lower plastic part 100 have a more suitable manufacturing cost. It also prevents backflowed electrolyte residue from remaining in the gap between the third side 114 and the second enclosure 12, thus avoiding a reduction in the service life of the energy storage device.

[0134] Please see again Figure 12 In some embodiments, the leakage part 10 also has a plurality of annular protrusions 14, which are disposed on the side of the bottom 13 away from the first enclosure part 11. Each annular protrusion 14 is disposed around the outer periphery of a second opening 105b, and different annular protrusions 14 are disposed around the outer periphery of different second openings 105b.

[0135] Understandably, the annular boss 14 is provided in a one-to-one correspondence with the second opening 105b. The annular boss 14 is located adjacent to the outer periphery of the second opening 105b.

[0136] It should be noted that the annular boss 14 is located on the side of the second sub-part 132 that is away from the first enclosure part 11 and the second enclosure part 12.

[0137] In this embodiment, by providing an annular boss 14, when the energy storage device shakes and the electrolyte sloshes or splashes, the annular boss 14, in conjunction with the bottom 13, can further prevent the shaking or splashing from entering the second opening 105b, increasing the difficulty for the electrolyte to enter the second opening 105b, thereby improving the anti-backflow and anti-overflow effect of the lower plastic part 100.

[0138] Please see again Figure 8 In some embodiments, the height h1 of the annular boss 14 is in the range of 0.1mm ≤ h1 ≤ 3mm.

[0139] Specifically, the height h1 of the annular boss 14 can be, but is not limited to, 0.1mm, 0.3mm, 0.5mm, 0.8mm, 1.0mm, 1.3mm, 1.5mm, 1.8mm, 2.0mm, 2.3mm, 2.5mm, 2.8mm, 3mm, etc.

[0140] In this embodiment, when the height h1 of the annular boss 14 is too small, the improvement in the anti-backflow and anti-overflow effect of the lower plastic part 100 is not significant; when the height h1 of the annular boss 14 is too large, it increases the thickness of the end cap assembly, making it easy for the lower plastic part 100 to abut against the electrode assembly inside the energy storage device, increasing the assembly difficulty of the end cap assembly, and making it impossible to install the end cap assembly. When the height h1 of the annular boss 14 is in the range of 0.1mm≤h1≤3mm, the lower plastic part 100 can have better anti-backflow and anti-overflow effects without affecting the installation of the end cap assembly.

[0141] In some embodiments, the lower plastic part 100 has a length direction and a width direction, and there are two of each of the second groove 104 and the second drain hole 105. The two second grooves 104 are spaced apart along the length direction on opposite sides of the first groove 103, and the two first openings 105a face the width direction.

[0142] In this embodiment, the two first openings 105a are oriented in opposite directions, that is, one faces one side in the width direction and the other faces the other side in the width direction.

[0143] The electrode assemblies of energy storage devices are typically arranged in a wound-like stack (e.g., wound-like stack along the length direction). The length direction of the energy storage device is the extension direction of one layer of electrode assembly. Therefore, when the energy storage device is shaken or swayed, the electrolyte is more likely to sway along the length direction of the energy storage device, and there is less swaying in the width direction. In this embodiment, by arranging the two drain holes 105 along the length direction, both first openings 105a can be oriented towards the width direction, which can better prevent the electrolyte from overflowing when the energy storage device is shaken.

[0144] Please see Figures 14 to 17 This application also provides an end cap assembly 200, which includes a top cap 210 and a lower plastic part 100 as described in this application. The top cap 210 has an injection hole 211; the lower plastic part 100 is located on one side of the top cap 210, and the plastic body 20 is disposed closer to the top cap 210 than the leakage part 10. The orthographic projection of the injection hole 211 on the second surface 102 at least partially overlaps with the orthographic projection of the first groove 103 on the second surface 102.

[0145] It should be noted that the end cap assembly 200 is used in the energy storage device. When the electrolyte is injected, it is injected through the injection hole 211. The electrolyte flows through the injection hole 211, sequentially through the first groove 103, the connecting channel 106, the second groove 104, the first opening 105a of the drain hole 105 and the second opening 105b of the drain hole 105, and finally enters the interior of the energy storage device.

[0146] Optionally, the top cover 210 may be made of, but is not limited to, at least one of aluminum or aluminum alloy.

[0147] Optionally, the top cover 210 also has an explosion-proof hole 212, which is spaced apart from the injection hole 211 along the length of the top cover 210. The end cover assembly 200 also includes an explosion-proof component 220. The explosion-proof valve assembly includes an explosion-proof sheet 221 and a protective sheet 222. The explosion-proof sheet 221 is used to close the explosion-proof hole 212. The protective sheet 222 is disposed on the side of the explosion-proof sheet 221 away from the lower plastic part 100 and is connected to the top cover 210. The lower plastic part 100 also has a vent hole 30 at the position corresponding to the explosion-proof hole 212.

[0148] Understandably, the explosion-proof sheet 221 and the protective sheet 222 are spaced apart. The explosion-proof sheet 221 is located near the side of the top cover 210 facing the lower plastic part 100, and the protective sheet 222 is located near the side of the top cover 210 away from the lower plastic part 100.

[0149] Optionally, the end cap assembly 200 further includes a positive electrode metal pressure block 230 and a positive electrode post 240. The positive electrode metal pressure block 230 is disposed on the side of the top cover 210 away from the lower plastic part 100, and the positive electrode post 240 is disposed on the side of the lower plastic part 100 away from the top cover 210. The positive electrode post 240 passes through the lower plastic part 100 and the top cover 210 sequentially from the side of the lower plastic part 100 away from the top cover 210, and is connected to the positive electrode metal pressure block 230.

[0150] Optionally, the end cap assembly 200 further includes a negative electrode metal pressure block 250 and a negative electrode post 260. The negative electrode metal pressure block 250 is disposed on the side of the top cover 210 away from the lower plastic part 100, and the negative electrode post 260 is disposed on the side of the lower plastic part 100 away from the top cover 210. The negative electrode post 260 passes through the lower plastic part 100 and the top cover 210 sequentially from the side of the lower plastic part 100 away from the top cover 210, and is connected to the negative electrode metal pressure block 250.

[0151] It should be noted that the positive electrode metal block 230 and the negative electrode metal block 250 are respectively disposed on opposite sides of the explosion-proof assembly 220 along the length of the top cover 210. The liquid injection hole 211 is located between the explosion-proof assembly 220 and the positive electrode metal block 230.

[0152] Optionally, the end cap assembly 200 further includes an upper plastic component 270, which is disposed between at least one of the positive electrode metal pressure block 230 and the top cover 210, and between the negative electrode metal pressure block 250 and the top cover 210, so that at least one of the positive electrode metal pressure block 230 and the negative electrode metal pressure block 250 is insulated from the top cover 210. That is, the upper plastic component 270 can be disposed between one of the positive electrode metal pressure block 230 and the top cover 210, or between the negative electrode metal pressure block 250 and the top cover 210, or both of them can be provided with the upper plastic component 270.

[0153] Optionally, the end cap assembly 200 further includes a sealing nail 280, which passes through the injection hole 211 and the first groove 103 to seal the injection hole 211 and the first groove 103 of the leakage part 10 after injection and before aluminum nail welding.

[0154] Please see Figure 18 and Figure 19 This application also provides an energy storage device 300, which includes: an end cap assembly 200 as described in this application, an adapter piece (not shown), and an electrode assembly 310. The adapter piece is disposed on the side of the lower plastic part 100 away from the top cover 210, and one end of the adapter piece is electrically connected to the end cap assembly 200. The electrode assembly 310 is disposed on the side of the adapter piece away from the end cap assembly 200, and the electrode assembly 310 is electrically connected to the end of the adapter piece away from the end cap assembly 200.

[0155] Optionally, the electrode assembly 310 includes a positive electrode 311, a diaphragm 312, and a negative electrode 313 stacked sequentially.

[0156] Optionally, the adapter includes a positive adapter and a negative adapter. The positive adapter is used to electrically connect the tab of the positive electrode 311 to the positive electrode post 240, and the negative adapter is used to electrically connect the tab of the negative electrode 313 to the negative electrode post 260.

[0157] Optionally, the energy storage device 300 further includes a housing 320 and an electrolyte. The housing 320 has a receiving cavity 321 with one end open. The receiving cavity 321 is used to receive the electrolyte and the electrode assembly 310. The end cap assembly 200 is connected to the housing 320 and is used to close the opening of the receiving cavity 321.

[0158] The energy storage device 300 in this application embodiment is an energy storage device 300 such as a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, or an energy storage battery. It is understood that the energy storage device 300 illustrated in the accompanying drawings is merely one form of the energy storage device 300 and should not be construed as a limitation on the energy storage device 300 provided in this application.

[0159] In this application, the terms "embodiment" and "implementation" mean that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of these phrases in various locations throughout the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this application can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the various embodiments of this application can be arbitrarily combined to form another embodiment that does not depart from the spirit and scope of the technical solution of this application, provided there is no contradiction between them.

[0160] 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 it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A lower plastic part, characterized in that, The lower plastic component is used for the end cap assembly of the energy storage device, and the lower plastic component includes: A leakage section has a first surface and a second surface disposed opposite to each other. The leakage section includes multiple first enclosure portions, second enclosure portions, and a bottom. The multiple first enclosure portions and the second enclosure portions are disposed on the same side of the bottom. The multiple first enclosure portions are circumferentially spaced on the bottom, and the multiple first enclosure portions and the bottom form a first groove. The first groove penetrates the first surface. The surface of the bottom opposite to the first enclosure portions is the second surface. The second enclosure portions surround the outer periphery of the multiple first enclosure portions and are respectively connected to the multiple first enclosure portions and the bottom. The first enclosure portions, the second enclosure portions, and the bottom form multiple second grooves. The second grooves penetrate the first surface and communicate with the first grooves. The leakage section also has multiple drain holes. The drain holes respectively penetrate the sidewall of the second groove and the second surface. One drain hole communicates with one second groove, and different drain holes communicate with different second grooves. A plastic body is provided around the outer periphery of the second enclosure portion and connected to one end of the second enclosure portion away from the bottom.

2. The lower plastic part according to claim 1, characterized in that, The drain hole has a first opening penetrating the sidewall of the second groove and a second opening penetrating the second surface. The first enclosure portion includes a first side portion, a second side portion, and a shielding portion. The multiple first sides portions of the multiple first enclosure portions and the bottom form a first groove. The second side portion and the shielding portion are both located on the side of the first side portion away from the first groove. The second side portion is bent and connected to the bottom, the first side portion, and the second enclosure portion respectively. The shielding portion is spaced apart from the bottom and forms the first opening. The shielding portion is bent and connected to the first side portion, the second side portion, and the second enclosure portion respectively. The second opening is located on the side of the shielding portion away from the first surface. The orthographic projection of the shielding portion on the second surface shields the second opening.

3. The lower plastic part according to claim 2, characterized in that, The two adjacent first sides form a connecting channel that connects the first groove and the second groove, and the connecting channel is offset from the first opening.

4. The lower plastic part according to claim 2, characterized in that, On the orthographic projection of the leakage part onto the second surface, there is a hollow gap between the shielding part and the bottom, and the range of d1 of the hollow gap is 0.01mm≤d1≤0.08mm.

5. The lower plastic part according to claim 2, characterized in that, The total area s of the first openings of the plurality of drainage holes is within the range of 7mm. 2 ≤s≤14.2mm 2 .

6. The lower plastic part according to claim 2, characterized in that, The surface of the first side facing the second groove is a cylindrical arc surface, and the surface of the second enclosure facing the second groove is a cylindrical arc surface or a cylindrical surface. The cylindrical arc surface of the first side and the cylindrical arc surface or cylindrical surface of the second enclosure are coaxially arranged, and the second side extends radially along the second enclosure.

7. The lower plastic part according to claim 2, characterized in that, Along the circumferential direction of the first groove, the first side portions of the plurality of first enclosure portions all protrude or bend in a clockwise direction relative to the second side portions; or, along the circumferential direction of the first groove, the first side portions of the plurality of first enclosure portions all protrude or bend in a counterclockwise direction relative to the second side portions.

8. The lower plastic part according to claim 3, characterized in that, The bottom includes a first sub-part and a plurality of second sub-parts, the plurality of second sub-parts being spaced apart around the outer periphery of the first sub-part. The first sub-part and a plurality of first side parts form a first groove, and the second sub-parts form a part of the second groove. The surface of the second sub-part facing the second groove includes an inclined surface, the inclined surface being located between the first opening and the communicating channel. The distance between the inclined surface and the second surface gradually increases from the end closer to the first opening toward the end closer to the first opening of the communicating channel.

9. The lower plastic part according to claim 8, characterized in that, The inclined surface is a plane, and the angle α between the inclined surface and the second surface is in the range of 1°≤α≤60°.

10. The lower plastic part according to claim 2, characterized in that, The second opening has a fan-shaped structure, and its size gradually decreases from one end near the second enclosure towards the side near the first groove.

11. The lower plastic part according to claim 2, characterized in that, There are two first enclosure portions, two second enclosure portions, and two second grooves and two drainage holes; the first side portion has a first end and a second end disposed opposite to each other, and the second side portion is disposed close to the first end; the first enclosure portion also includes a third side portion, which is disposed at the second end and bent in a direction away from the first groove relative to the first side portion; the second side portion of one of the two first enclosure portions and the third side portion of the other are disposed facing each other to define the same second groove.

12. The lower plastic part according to claim 11, characterized in that, The surface of the shielding portion facing the second groove and close to the first opening is a third surface. The third side portion has a fourth surface facing the drain hole and the second groove. The distance between the third surface and the fourth surface defining the same second groove gradually increases from the end close to the first groove toward the end away from the first groove.

13. The lower plastic part according to claim 12, characterized in that, The angle β between the third and fourth surfaces of the same second groove is defined as follows: 0 ≤ β ≤ 60°.

14. The lower plastic part according to claim 2, characterized in that, The leakage part also has multiple annular protrusions, which are disposed on the side of the bottom away from the first enclosure part. Each annular protrusion surrounds the outer periphery of a second opening, and different annular protrusions surround different second openings.

15. The lower plastic part according to claim 14, characterized in that, The height h1 of the annular boss is in the range of 0.1mm≤h1≤3mm.

16. An end cap assembly, characterized in that, include: Top cover, the top cover having a liquid injection hole; as well as The lower plastic part according to any one of claims 1-15, wherein the lower plastic part is located on one side of the top cover, the plastic body is disposed closer to the top cover than the leakage portion, and the orthographic projection of the injection hole on the second surface at least partially overlaps with the orthographic projection of the first groove on the second surface.

17. An energy storage device, characterized in that, include: The end cap assembly as claimed in claim 16; An adapter piece is disposed on the side of the lower plastic part opposite to the top cover, and one end of the adapter piece is electrically connected to the end cover assembly; as well as An electrode assembly is disposed on the side of the adapter piece away from the end cap assembly, and the electrode assembly is electrically connected to the end of the adapter piece away from the end cap assembly.

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