End cover assembly and energy storage apparatus

Abstract

The present application provides an end cover assembly and an energy storage apparatus. The end cover assembly of the present application comprises: a top cover, the top cover being provided with an electrolyte injection hole; a lower plastic part, the lower plastic part being located on one side of the top cover, the lower plastic part having a first surface and a second surface arranged opposite one another, the lower plastic part comprising: a vent portion, a leakage path portion, and a body portion, the vent portion having a plurality of first vent holes arranged in a spaced apart manner; the leakage path portion comprises a stopping portion and an enclosure portion which are bent and connected to each other, the enclosure portion and the stopping portion jointly defining an electrolyte leakage groove penetrating through the first surface, the leakage path portion being further provided with an electrolyte discharge hole, the electrolyte discharge hole penetrating through both the stopping portion and the enclosure portion, the leakage path portion falling within an orthographic projection of the second surface, a hollowed-out gap being formed between the stopping portion and the enclosure portion, and the hollowed-out gap and the electrolyte injection hole being arranged in a staggered manner; the body portion is connected to both the vent portion and the leakage path portion, the body portion being arranged at least around a periphery of the leakage path portion, the body portion having a communicating channel penetrating through the first surface, and the communicating channel communicating with the plurality of first vent holes and the electrolyte leakage groove, respectively.

Description

End cap assembly and energy storage device

[0001] This application claims priority to Chinese Patent Application No. 202411016733.4, filed on July 26, 2024, entitled “End Cap Assembly and Energy Storage Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electronics, specifically to an end cap assembly and an energy storage device. Background Technology

[0003] In the battery cell manufacturing process, after the electrolyte is injected into the cell, the cell is transported to the next process via a conveyor belt. At this time, the injection port on the lower plastic of the cell end cap is not sealed, and the conveyor belt experiences bumps and swaying during transport. Most of the existing injection ports are straight-through designs. Therefore, during the transport process before the injection port is sealed, the electrolyte can easily overflow from the injection port, resulting in a reduction in the amount of electrolyte inside the cell and a shortened cycle life. Secondly, it contaminates the explosion-proof valve patch and the terminal post of the cell, causing the cell to need to be reworked or scrapped. Furthermore, when sealing the injection port with sealing nails, the sealing nails can easily fall into the cell, causing temporary sealing failure. Weld slag generated from the subsequent welding of the sealing aluminum nails can easily fall into the cell, causing a short circuit. Summary of the Invention

[0004] This application provides an end cap assembly applied to an energy storage device, which can better prevent electrolyte leakage from the energy storage device when the energy storage device shakes or vibrates.

[0005] In a first aspect, embodiments of this application provide an end cap assembly for an energy storage device, the end cap assembly comprising:

[0006] Top cover, the top cover having a liquid injection hole;

[0007] A lower plastic component is located on one side of the top cover. The lower plastic component has a first surface and a second surface opposite in their thickness directions. The first surface faces the lower plastic component. The lower plastic component includes a venting section, a draining section, and a body section. The venting section has a plurality of spaced-apart first vent holes, which respectively penetrate the first surface and the second surface. The draining section is spaced apart from the venting section and includes a bent and connected abutment and a surrounding section. The surrounding section surrounds the outer periphery of the abutment, and the surrounding section and the abutment form a draining groove penetrating the first surface. The liquid part also has a drain hole, which is connected to the leakage groove and located near the abutment. The drain hole passes through the abutment and the enclosure. On the orthographic projection of the leakage part onto the second surface, there is a hollow gap between the abutment and the enclosure, which is offset from the injection hole. The body part is connected to the venting part and the leakage part respectively. The body part is at least arranged around the outer periphery of the leakage part and connected to the end of the enclosure part away from the abutment. The body part has a connecting channel that passes through the first surface, and the connecting channel connects to the plurality of first venting holes and the leakage groove respectively.

[0008] Secondly, embodiments of this application also provide an energy storage device, which includes:

[0009] The end cap assembly described in the embodiments of this application;

[0010] 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

[0011] 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.

[0012] The end cap assembly of this application includes a top cover and a lower plastic part. The lower plastic part includes a venting part, a draining part, and a body part. The draining part includes a bent and connected abutment part and a surrounding part. The surrounding part and the abutment part form a draining groove that penetrates the first surface. The draining part also has a drain hole that communicates with the draining groove. In this way, when the lower plastic part is applied to the end cap assembly of the energy storage device and the energy storage device experiences bumps and swaying after liquid injection but before the liquid injection hole of the top cover is closed, the abutment part can prevent electrolyte from entering the draining groove, thereby better reducing electrolyte overflow. In addition, when a small amount of electrolyte impacts the drain hole upwards, most of it will be blocked by the surrounding part and returned to the inside of the energy storage device. Even if a small amount of electrolyte enters the draining groove, since the drain hole also penetrates the abutment part, the electrolyte entering the draining groove will fall back into the energy storage device under the action of gravity, avoiding the accumulation of liquid in the draining groove. Furthermore, the retaining section prevents the sealing nails of the end cap assembly from falling into the energy storage device, thus preventing temporary sealing failure. Weld slag from subsequent welding of the sealing aluminum nails could easily fall into the energy storage device, causing a short circuit. Moreover, the drain hole penetrates the retaining section. After the electrolyte enters the drain hole from the leakage tank, it is sprayed further, quickly dispersing the injected electrolyte to a wider area and improving the uniformity of electrolyte wetting of the electrode components of the energy storage device. Furthermore, the main body has a connecting channel between the leakage tank and multiple first vent holes. When the electrolyte injection speed is high and the flow rate is large, and the drain hole cannot keep up with the flow, the electrolyte will flow through the connecting channel and multiple first vent holes into the energy storage device, thereby improving the injection rate and efficiency. Furthermore, by setting the perforated gaps and the injection holes separately, when the end cap assembly is applied to the energy storage device, and the energy storage device shakes, when the electrolyte impacts upward through the perforated gaps, the electrolyte will also be blocked by the top cap and returned to the leakage tank, flowing back into the energy storage device through the drain hole. This can better prevent the electrolyte from overflowing and also avoid the electrolyte directly impacting the sealing nails in the injection hole, thus affecting the sealing performance of the sealing nails. Attached Figure Description

[0013] 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.

[0014] Figure 1 is a structural schematic diagram of the lower plastic part according to the first embodiment of this application.

[0015] Figure 2 is a structural schematic diagram of the lower plastic part from another perspective of the first embodiment of this application.

[0016] Figure 3 is a front view of the lower plastic part according to the first embodiment of this application.

[0017] Figure 4 is a cross-sectional view of the lower plastic part of the first embodiment of this application along the AA direction in Figure 3.

[0018] Figure 5 is a structural schematic diagram of the lower plastic part according to the second embodiment of this application.

[0019] Figure 6 is a structural schematic diagram of the lower plastic part from another perspective according to the second embodiment of this application.

[0020] Figure 7 is a front view of the lower plastic part according to the second embodiment of this application.

[0021] Figure 8 is an enlarged view of the area within the dashed box I in Figure 5.

[0022] Figure 9 is an enlarged view of the area within the dashed box II in Figure 7.

[0023] Figure 10 is an enlarged view of the area within the dashed box III in Figure 5.

[0024] Figure 11 is a structural schematic diagram of the lower plastic part from another perspective according to the second embodiment of this application.

[0025] Figure 12 is an enlarged view of the area within the dashed box IV in Figure 11.

[0026] Figure 13 is a structural schematic diagram of an end cap assembly according to an embodiment of this application.

[0027] Figure 14 is an exploded structural diagram of an end cap assembly according to an embodiment of this application.

[0028] Figure 15 is a structural schematic diagram of an end cap assembly according to an embodiment of this application from another perspective.

[0029] Figure 16 is an exploded structural diagram of an end cap assembly according to an embodiment of this application from another perspective.

[0030] Figure 17 is a schematic diagram of the structure of an energy storage device according to an embodiment of this application.

[0031] Figure 18 is a cross-sectional view of an energy storage device according to an embodiment of this application along the BB direction in Figure 17.

[0032] Explanation of reference numerals in the attached drawings: 100 - Lower plastic part, 10 - First surface, 20 - Second surface, 30 - Vent, 31 - First vent hole, 32 - First vent sub-part, 33 - Second vent sub-part, 34 - Third vent sub-part, 35 - Groove, 36 - Second vent hole, 40 - Leakage part, 41 - Blocking part, 42 - Enclosing part, 43 - Leakage groove, 44 - Drainage hole, 45 - Hollowed-out gap, 50 - Main body, 51 - Connecting channel, 52 - First sidewall, 53 - Bottom wall, 54 - Second sidewall, 55 - First main body sub-part, 56 - Second main body sub-part, 60 - First blocking component, 70 - Second blocking component, 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 - Housing, 321 - Reception cavity. Detailed Implementation

[0033] 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.

[0034] 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.

[0035] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0036] 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.

[0037] A rechargeable battery, also known as a secondary battery or storage battery, is a battery that can be recharged after being discharged to reactivate its active materials and continue to be used. The recyclable nature of rechargeable batteries has made them a primary power source for electrical devices. As the demand for rechargeable batteries increases, people have higher requirements for their safety and cost-effectiveness.

[0038] In the battery cell manufacturing process, after the electrolyte is injected into the cell, the cell is transported to the next process via a conveyor belt. At this time, the injection port on the lower plastic of the cell end cap is not sealed, and the conveyor belt experiences bumps and swaying during transport. Most of the existing injection ports are straight-through designs. Therefore, during the transport process before the injection port is sealed, the electrolyte can easily overflow from the injection port, resulting in a reduction in the amount of electrolyte inside the cell and a shortened cycle life. Secondly, it contaminates the explosion-proof valve patch and the terminal post of the cell, causing the cell to need to be reworked or scrapped. Furthermore, when sealing the injection port with sealing nails, the sealing nails can easily fall into the cell, causing temporary sealing failure. Weld slag generated from the subsequent welding of the sealing aluminum nails can easily fall into the cell, causing a short circuit.

[0039] Figure 1 is a structural schematic diagram of the lower plastic part 100 according to the first embodiment of this application. Figure 2 is a structural schematic diagram of the lower plastic part 100 from another perspective according to the first embodiment of this application. Figure 3 is a front view of the lower plastic part 100 according to the first embodiment of this application. Figure 4 is a cross-sectional structural schematic diagram of the lower plastic part 100 according to the first embodiment of this application along the AA direction in Figure 3.

[0040] Please refer to Figures 1 to 4. This application provides a lower plastic component 100 for an energy storage device. The lower plastic component 100 has a first surface 10 and a second surface 20 arranged opposite to each other in the thickness direction (as shown by arrow Z in Figure 1). The lower plastic component 100 includes an exhaust portion 30, a leakage portion 40, and a body portion 50. The exhaust portion 30 has a plurality of first exhaust holes 31 spaced apart, each penetrating the first surface 10 and the second surface 20. The leakage portion 40 is spaced apart from the exhaust portion 30 and includes a bent and connected abutment portion 41 and a surrounding portion 42. The surrounding portion 42 surrounds the outer periphery of the abutment portion 41. Part 42 and the blocking part 41 form a leakage groove 43 that penetrates the first surface 10. The leakage part 40 also has a drain hole 44, which is connected to the leakage groove 43 and disposed near the blocking part 41. The drain hole 44 penetrates the blocking part 41 and the blocking part 42 respectively. The body part 50 is connected to the venting part 30 and the leakage part 40 respectively. The body part 50 is disposed at least around the outer periphery of the leakage part 40 and connected to the end of the blocking part 42 away from the blocking part 41. The body part 50 has a connecting channel 51 that penetrates the first surface 10. The connecting channel 51 is connected to the plurality of first venting holes 31 and the leakage groove 43 respectively.

[0041] The term "multiple" refers to two or more, such as, but not limited to, two, three, four, five, six, etc.

[0042] 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 body part 50 is closer to the outer surface of the end cap assembly than the abutment part 41; in other words, the abutment part 41 is closer to the interior of the energy storage device than the body part 50.

[0043] Optionally, the venting part 30, the draining part 40, and the body part 50 are an integral structure, and the venting part 30, the draining part 40, and the body part 50 are different parts of the same component. The venting part 30, the draining part 40, and the body part 50 can be formed by an integral injection molding process.

[0044] Understandably, the connecting channel 51 is located between the first vent 31 and the leakage tank 43.

[0045] Understandably, the drain groove 43 is positioned away from the second surface 20.

[0046] Understandably, the blocking part 41 is located on the side of the main body 50 opposite to the communicating channel 51. The blocking part 41 and the main body 50 are spaced apart along the thickness direction of the lower plastic part 100. It is also understood that the blocking part 41 and the main body 50 are located at opposite ends of the enclosure part 42.

[0047] 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 10 is closer to the outer surface of the end cap assembly than the second surface 20.

[0048] It should be noted that when the lower plastic part 100 is applied to the end cap assembly of the energy storage device, and electrolyte is injected (i.e., electrolyte is injected), the electrolyte is injected into the leakage groove 43 along the first surface 10 side of the lower plastic part 100, and then enters the interior of the energy storage device through the drain hole 44, or enters the interior of the energy storage device through the connecting channel 51 and the first vent hole 31.

[0049] The lower plastic part 100 in this embodiment can be manufactured using an injection mold through injection molding. The injection mold includes an upper mold and a lower mold, which together form a mold cavity. A first protrusion is provided on the surface of the upper mold facing the mold cavity at a position corresponding to the drain groove 43, and a second protrusion is provided on the surface of the lower mold facing the mold cavity at a position corresponding to the drain hole 44. The first protrusion and the second protrusion are positioned as close as possible to each other. After injection molding, the drain groove 43 is formed at the position of the first protrusion, and the drain hole 44 is formed at the position of 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, thus greatly reducing the manufacturing cost of the injection mold and consequently reducing the manufacturing cost of the lower plastic part 100.

[0050] The lower plastic part 100 of this application embodiment includes a venting part 30, a draining part 40, and a body part 50. The draining part 40 includes a bent and connected abutment part 41 and a surrounding part 42. The surrounding part 42 and the abutment part 41 form a draining groove 43 that penetrates the first surface 10. The draining part 40 also has a drain hole 44 that communicates with the draining groove 43. Thus, when the lower plastic part 100 is applied to the end cap assembly of an energy storage device and the energy storage device is filled with liquid, the liquid filling hole of the top cap is not closed. When bumps or swaying occur, the baffle 41 can prevent electrolyte from entering the leakage tank 43, thereby reducing electrolyte spillage. Furthermore, when a small amount of electrolyte impacts the drain hole 44, most of it will be blocked by the enclosure 42 and returned to the energy storage device. Even if a small amount of electrolyte enters the leakage tank 43, since the drain hole 44 is also penetrated by the baffle 41, the electrolyte entering the leakage tank 43 will fall back into the energy storage device under gravity, preventing liquid accumulation in the leakage tank 43. In addition, the baffle 41 can also prevent the sealing nails of the end cap assembly from falling into the energy storage device, thus preventing temporary sealing failure. Subsequent welding slag from the sealing aluminum nails could easily fall into the energy storage device, causing a short circuit. Furthermore, the drain hole 44 penetrates the enclosure 42. After the electrolyte enters the drain hole 44 from the drain tank 43, the electrolyte is sprayed further away, thereby 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. Moreover, the main body 50 is provided with a connecting channel 51 that connects the drain tank 43 to multiple first vent holes 31. When the electrolyte injection speed is fast and the injected electrolyte flow rate is large, and the drain hole 44 cannot keep up with the flow, the electrolyte will flow through the connecting channel 51 through the multiple first vent holes 31 and enter the interior of the energy storage device, thereby improving the injection rate and injection efficiency.

[0051] In some embodiments, the leakage portion 40 is projected onto the second surface 20, and a perforated gap 45 is formed between the blocking portion 41 and the enclosure portion 42.

[0052] Optionally, the range of d for the hollowed-out gap 45 is 0.01mm≤d≤2.8mm.

[0053] It should be noted that the perforated gap 45 is formed by the drainage hole 44.

[0054] Specifically, the width d of the cutout gap can be, but is not limited to, 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.1mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, etc.

[0055] In this embodiment, if the width d of the hollowed-out gap is too small, it increases the difficulty of manufacturing the lower plastic part 100; if the width d of the hollowed-out gap is too large, it reduces the shielding effect of the blocking part 41, and cannot effectively prevent the electrolyte from entering the leakage tank 43 from the drain hole 44, and thus overflowing outside the energy storage device. When the range of d of the hollowed-out gap 45 is 0.01mm≤d≤2.8mm, it can better play a blocking role and prevent the electrolyte from entering the leakage tank 43 from the drain hole 44, and thus overflowing outside the energy storage device.

[0056] In some embodiments, the leakage portion 40 and the venting portion 30 are arranged at intervals along the length direction of the lower plastic part 100 (as shown by arrow Y in FIG1), and the number of drainage holes 44 is two, which are arranged along the width direction of the lower plastic part 100 (as shown by arrow X in FIG1).

[0057] Understandably, the two drain holes 44 are spaced apart and are located on opposite sides of the drain portion 40 along the width direction of the lower plastic part 100.

[0058] The electrode assemblies of the energy storage device are typically arranged in a racetrack-shaped, wound-up stack (e.g., wound-up stack along the length direction). The two ends of the energy storage device along the length direction are the bends of the racetrack, with a large gap between them and the casing. This gap stores a large amount of electrolyte. Therefore, when the energy storage device is shaken or vibrated, the electrolyte is more likely to splash and slosh along the length direction of the energy storage device (i.e., the length direction of the lower plastic part 100), while splashing and sloshing in the width direction is less. In this embodiment, by making the two drain holes 44 along the width... The electrolyte is arranged in a directional manner. When the energy storage device shakes along the length of the lower plastic part 100, the electrolyte is blocked by the blocking part 41 and the enclosure part 42 and will not enter the leakage tank 43, thus preventing it from overflowing out of the energy storage device. When the electrolyte shakes along the width, due to the arrangement of the drain hole 44, only a very small amount of electrolyte will enter the leakage tank 43 through the drain hole 44, which is insufficient to overflow out of the energy storage device. This can better prevent the electrolyte from overflowing when the energy storage device shakes.

[0059] In some embodiments, the cross-sectional area A of the drain hole 44 is in the range of 0.3 mm. 2 ≤A≤3mm2 Specifically, the cross-sectional area A of the drain hole 44 can be, but is not limited to, 0.3 mm. 2 0.5mm 2 0.8mm 2 1.0mm 2 1.2mm 2 1.4mm 2 1.6mm 2 1.8mm 2 2.0mm 2 2.2mm 2 2.4mm 2 2.6mm 2 2.8mm 2 3mm 2 wait.

[0060] In this embodiment, if the cross-sectional area A of the drain hole 44 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 may cause electrolyte splashing during injection, resulting in electrolyte spillage outside the energy storage device. If the cross-sectional area A of the drain hole 44 is too large, the electrolyte may easily pass through the drain hole 44 and enter the leakage tank 43 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 cross-sectional area A of the drain hole 44 is within the range of 0.3 mm... 2 ≤A≤3mm 2 When the lower plastic part 100 is applied to an energy storage device, the energy storage device has a higher injection rate and better anti-backflow and anti-overflow effects.

[0061] In some embodiments, the cross-sectional area S3 of the connecting channel 51 ranges from 2 mm. 2 ≤S3≤6mm 2 Specifically, the cross-sectional area S3 of the connecting channel 51 can be, but is not limited to, 2 mm. 2 2.5mm 2 3mm 2 3.5mm 2 4mm 2 4.5mm 2 5mm 2 5.5mm 2 6mm 2 wait.

[0062] In this embodiment, if the cross-sectional area S3 of the connecting channel 51 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 may cause electrolyte splashing during injection, resulting in electrolyte spillage outside the energy storage device. If the cross-sectional area S3 of the connecting channel 51 is too large, the electrolyte may easily pass through the drain hole 44 and enter the leakage tank 43 during the oscillation process 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 cross-sectional area S3 of the connecting channel 51 is within the range of 2mm... 2 ≤S3≤6mm 2 When the lower plastic part 100 is applied to an energy storage device, the energy storage device has a higher injection rate and better anti-backflow and anti-overflow effects.

[0063] Optionally, the number of connecting channels 51 can be one or more. When there are multiple connecting channels 51, each connecting channel 51 is connected to multiple first vent holes 31 and the leakage tank 43 at both ends.

[0064] In one specific embodiment, the number of the connecting channel 51 is one, and the venting part 30, the connecting channel 51, and the draining part 40 are arranged sequentially along the length direction of the lower plastic part 100. In other embodiments, the number of the connecting channel 51 is two, and the two connecting channels 51 are arranged at intervals along the width direction of the lower plastic part 100, as shown in FIG1.

[0065] Figure 5 is a structural schematic diagram of the lower plastic part 100 according to the second embodiment of this application. Figure 6 is a structural schematic diagram of the lower plastic part 100 from another perspective according to the second embodiment of this application. Figure 7 is a front view of the lower plastic part 100 according to the second embodiment of this application. Figure 8 is an enlarged view of the area within the dashed box I in Figure 5. Figure 9 is an enlarged view of the area within the dashed box I in Figure 7.

[0066] Please refer to Figures 5 to 9. In some embodiments, the body portion 50 has a first sidewall 52, a bottom wall 53, and a second sidewall 54 that surround the communicating channel 51 and are bent and connected on one side. The first sidewall 52 and the second sidewall 54 are arranged along the width direction of the lower plastic part 100. The lower plastic part 100 also includes a first blocking member 60 and a second blocking member 70. The first blocking member 60 is located on the bottom wall 53. One end of the first blocking member 60 is connected to the first sidewall 52, and the other end is away from the first sidewall 52. The end of the first blocking member 60 connected to the first sidewall 52 is closer to the drain groove 43 than the end of the first blocking member 60 away from the first sidewall 52. The second blocking member 70 is located on the bottom wall 53. One end of the second blocking member 70 is connected to the second sidewall 54, and the other end is away from the second sidewall 54. The end of the second blocking member 70 connected to the second sidewall 54 is closer to the drain groove 43 than the end of the second blocking member 70 away from the second sidewall 54.

[0067] Understandably, the first blocking member 60 is spaced apart from the second sidewall 54, and the second blocking member 70 is spaced apart from the first sidewall 52.

[0068] Understandably, the end of the first blocking member 60 that connects to the first sidewall 52 is located between the end of the first blocking member 60 that is away from the first sidewall 52 and the leakage groove 43.

[0069] Understandably, the end of the second blocking member 70 that connects to the second sidewall 54 is located between the end of the second blocking member 70 that is away from the first sidewall 52 and the leakage groove 43.

[0070] Optionally, the number of first blocking members 60 can be one or more. When there are multiple first blocking members 60, the multiple first blocking members 60 are arranged sequentially at intervals along the length direction of the lower plastic part 100.

[0071] Optionally, the number of second blocking members 70 can be one or more. When there are multiple second blocking members 70, the multiple second blocking members 70 are arranged sequentially at intervals along the length direction of the lower plastic part 100.

[0072] When there are multiple of the first blocking member 60 and the second blocking member 70, the first blocking member 60 and the second blocking member 70 are alternately arranged along the length direction of the lower plastic part 100 to form a flow-blocking maze structure.

[0073] In some embodiments, the first sidewall 52 is parallel to the second sidewall 54, and both the first sidewall 52 and the second sidewall 54 are perpendicular to the bottom wall 53.

[0074] In one specific embodiment, there are two first blocking members 60 and one second blocking member 70, with the second blocking member 70 located between the two first blocking members 60.

[0075] Optionally, the first blocking member 60, the second blocking member 70, the venting part 30, the leaking part 40, and the body part 50 are an integral structure, and the first blocking member 60, the second blocking member 70, the venting part 30, the leaking part 40, and the body part 50 are different parts of the same component. The first blocking member 60, the second blocking member 70, the venting part 30, the leaking part 40, and the body part 50 can be formed by integral injection molding.

[0076] In this embodiment, by providing a first blocking member 60 and a second blocking member 70, with one end of the first blocking member 60 connected to the first sidewall 52 and the other end facing away from the first sidewall 52, the end of the first blocking member 60 connected to the first sidewall 52 is closer to the leakage groove 43 than the end of the first blocking member 60 facing away from the first sidewall 52; similarly, one end of the second blocking member 70 is connected to the second sidewall 54 and the other end facing away from the second sidewall 54, the end of the second blocking member 70 connected to the second sidewall 54 is closer to the leakage groove 43 than the end of the second blocking member 70 facing away from the second sidewall 54; thus, during electrolyte injection, the first blocking member 60, the first sidewall 52, and the second blocking member... The angle between the first blocking member 60 and the second blocking member 70 facing the side of the second sidewall 54 facing the leakage part 40 is an obtuse angle. When the electrolyte fills the leakage tank 43, the electrolyte will pass through the connecting channel 51, through multiple first vent holes 31, and into the energy storage device. At this time, the first blocking member 60 and the second blocking member 70 will not block the flow of electrolyte, thus not affecting the injection. However, when the energy storage device shakes and the electrolyte splashes through the multiple first vent holes 31 into the connecting channel 51, the angle between the first blocking member 60 and the first sidewall 52, and the angle between the second blocking member 70 and the second sidewall 54 facing the vent part 30, is an acute angle. This allows the first blocking member 60 and the second blocking member 70 to prevent the electrolyte from flowing into the leakage tank 43, thereby preventing a large amount of electrolyte from entering the leakage tank 43 and overflowing from it. Furthermore, due to the blocking effect of the first blocking member 60 and the second blocking member 70, during the injection, a large amount of electrolyte enters the leakage tank 43 and flows through the connecting channel venting section 30. After passing through the multiple first venting holes 31 of the venting section 30, it enters the position of the electrode assembly below the lower plastic part 100. The large flow of electrolyte can be slowed down by the tree-like interlaced first blocking member 60 and second blocking member 70, so that the electrolyte flows in relatively evenly and slowly, avoiding direct impact on the electrode assembly.

[0077] In some embodiments, the minimum cross-sectional area of ​​the passage defined between adjacent first stop members 60 and second stop members 70 is in the range of 2 mm. 2 Up to 6mm 2 Specifically, the minimum cross-sectional area of ​​the passage defined between adjacent first blocking member 60 and second blocking member 70 can be, but is not limited to, 2 mm. 2 2.5mm 2 3mm 2 3.5mm 2 4mm 2 4.5mm 2 5mm 2 5.5mm 2 6mm 2 wait.

[0078] In this embodiment, if the minimum cross-sectional area of ​​the passage defined between adjacent first blocking members 60 and second blocking members 70 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 may cause electrolyte splashing during injection, resulting in electrolyte spillage outside the energy storage device. If the minimum cross-sectional area of ​​the passage defined between adjacent first blocking members 60 and second blocking members 70 is too large, the electrolyte may easily pass through the drain hole 44 and enter the leakage tank 43 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 vibrates. When the minimum cross-sectional area of ​​the passage defined between adjacent first blocking members 60 and second blocking members 70 is within the range of 2mm... 2 Up to 6mm 2 When the lower plastic part 100 is applied to an energy storage device, the energy storage device has a higher injection rate and better anti-backflow and anti-overflow effects.

[0079] Please refer to Figure 9. In some embodiments, the angle α between the first blocking member 60 and the first sidewall 52 is in the range of 100°C ≤ α ≤ 150°C.

[0080] It should be noted that the angle α between the first blocking member 60 and the first sidewall 52 in this application refers to the angle between the sidewall of the first blocking member 60 facing the leakage part 40 and the first sidewall 52.

[0081] Specifically, the angle α between the first blocking member 60 and the first sidewall 52 can be, but is not limited to, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc.

[0082] In this embodiment, if the angle α between the first blocking member 60 and the first sidewall 52 is too small, the rate at which the electrolyte enters the multiple first vent holes 31 through the connecting channel 51 is too low during electrolyte injection, thus reducing the injection efficiency. If the angle α between the first blocking member 60 and the first sidewall 52 is too large, the blocking effect of the first blocking member 60 on the countercurrent electrolyte is reduced when the energy storage device shakes and the electrolyte flows back into the connecting channel 51 through the multiple first vent holes 31.

[0083] Optionally, the angle β between the second blocking member 70 and the second sidewall 54 is in the range of 100°C ≤ β ≤ 150°C.

[0084] It should be noted that the angle β between the second blocking member 70 and the second side wall 54 in this application refers to the angle between the side wall of the second blocking member 70 facing the leakage part 40 and the second side wall 54.

[0085] Specifically, the angle β between the second blocking member 70 and the second sidewall 54 can be, but is not limited to, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc.

[0086] In this embodiment, if the angle β between the second blocking member 70 and the second sidewall 54 is too small, the rate at which the electrolyte enters the multiple first vent holes 31 through the connecting channel 51 is too low during electrolyte injection, thus reducing the injection efficiency. If the angle β between the second blocking member 70 and the second sidewall 54 is too large, the blocking effect of the second blocking member 70 on the countercurrent electrolyte is reduced when the energy storage device shakes and the electrolyte flows back into the connecting channel 51 through the multiple first vent holes 31.

[0087] Please refer to Figure 9. In some embodiments, along the length direction of the lower plastic part 100, the first blocking member 60 and the second blocking member 70 partially overlap, and the length L of the overlapping portion of the first blocking member 60 and the second blocking member 70 is in the range of 0.5mm≤L≤5mm.

[0088] Specifically, the length L of the overlapping portion of the first blocking member 60 and the second blocking member 70 can be, but is not limited to, 0.5mm, 0.8mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, 5mm, etc.

[0089] In this embodiment, if the length L of the overlapping portion of the first blocking member 60 and the second blocking member 70 is too small, the anti-backflow effect of the first blocking member 60 and the second blocking member 70 on the electrolyte splashed into the communicating channel 51 from the multiple first vent holes 31 is reduced; if the length L of the overlapping portion of the first blocking member 60 and the second blocking member 70 is too large, the cross-sectional area of ​​the channel formed by the first blocking member 60 and the second blocking member 70 is too small, which reduces the electrolyte injection rate and injection efficiency during electrolyte injection.

[0090] As shown in Figures 2 and 6, in some embodiments, the body portion 50 protrudes from the second surface 20 at the position corresponding to the connecting channel 51.

[0091] The first surface 10 of the body part 50 is recessed at the position of the connecting channel 51, forming the connecting channel 51. This makes the thickness of the body part 50 thinner at this position. In this embodiment, the body part 50 protrudes from the second surface 20 at the position corresponding to the connecting channel 51, so that a protrusion is formed on the side of the second surface 20. This protrusion can act as a reinforcing rib, increasing the structural strength between the venting part 30 and the draining part 40 of the lower plastic part 100. This prevents the electrolyte from impacting the bottom of the draining groove 43 of the lower plastic part 100 (i.e., the blocking part 41) when injected at high speed, causing the middle area of ​​the long plate-shaped lower plastic part 100 to sink and deform.

[0092] Figure 10 is an enlarged view of the area within the dashed box III in Figure 5. Figure 11 is a structural schematic diagram of the lower plastic part 100 from another perspective of the second embodiment of this application. Figure 12 is an enlarged view of the area within the dashed box IV in Figure 11.

[0093] Please refer to Figures 10 and 11. In some embodiments, the exhaust section 30 includes a first exhaust sub-section 32, a second exhaust sub-section 33, and a third exhaust sub-section 34 that are sequentially bent and connected. The first exhaust sub-section 32 and the third exhaust sub-section 34 are respectively located on the same side of the second exhaust sub-section 33. The first exhaust sub-section 32, the second exhaust sub-section 33, and the third exhaust sub-section 34 form a groove 35 facing away from the second surface 20. The groove 35 communicates with the communicating channel 51. The body section 50 includes a first body sub-section 55 and a second body sub-section 56. The first body sub-section 55 and the second body sub-section 56 are respectively located on the exhaust section. On opposite sides of part 30, the first body sub-part 55 is connected to the end of the first vent sub-part 32 opposite to the second vent sub-part 33 and is disposed around the outer periphery of the leakage part 40, and the first body sub-part 55 has the communicating channel 51; the second body sub-part 56 is connected to the end of the third vent sub-part 34 opposite to the second vent sub-part 33; the second vent sub-part 33 has the plurality of first vent holes 31, and the plurality of first vent holes 31 communicate with the groove 35; the first vent sub-part 32 and the third vent sub-part 34 each have a plurality of second vent holes 36 spaced apart, and the plurality of second vent holes 36 communicate with the groove 35.

[0094] Understandably, the surface of the exhaust portion 30 connected to the first surface 10 is at least partially recessed into the first surface 10 to form a groove 35, and the surface of the arrangement portion connected to the second surface 20 is at least partially protruding from the second surface 20.

[0095] Understandably, both the first vent 31 and the second vent 36 are connected to the groove 35, and through the groove 35 are connected to the connecting channel 51, and thus to the leakage tank 43.

[0096] It should be noted that the penetration direction of the first vent 31 intersects the penetration direction of the second vent 36. In a specific embodiment, the penetration direction of the first vent 31 is perpendicular to the penetration direction of the second vent 36. For example, the first vent 31 penetrates the second vent sub-section 33 along the thickness direction of the lower plastic part 100, and the second vent 36 penetrates the first vent sub-section 32 or the second vent sub-section 33 along the length direction of the lower plastic part 100.

[0097] Optionally, the plurality of second vent holes 36 of the first vent sub-part 32 are arranged at intervals along the width direction of the lower plastic part 100, and the plurality of second vent holes 36 of the second vent sub-part 33 are arranged at intervals along the width direction of the lower plastic part 100.

[0098] In this embodiment, the lower plastic part 100 is applied to a battery. When electrolyte is injected, the electrolyte is injected from the injection hole of the top cover and flows into the leakage groove 43 of the lower plastic part 100. On the one hand, the electrolyte enters the energy storage device through the drain hole 44 at the bottom of the leakage groove 43. On the other hand, when the electrolyte in the leakage groove 43 is filled to the position of the connecting channel 51, a part of the electrolyte will enter the groove 35 through the connecting channel 51, and then enter the energy storage device through the first vent hole 31 and the second vent hole 36 on the vent 30 that are connected to the groove 35. The electrolyte enters the energy storage device through multiple paths, which can not only improve the injection efficiency, but also disperse the injected electrolyte over a larger area and improve the wetting effect of the electrolyte on the electrode components.

[0099] In this embodiment, when the lower plastic part 100 is assembled into the battery, the surface of the second venting sub-part 33 facing the inside of the battery may abut against the top of the electrode assembly, thereby blocking the first venting sub-hole. Thus, during electrolyte injection, the electrolyte cannot pass through the first venting hole 31 of the lower plastic part 100 and enter the battery. In this embodiment, by providing multiple second venting holes 36 on the first venting sub-part 32 and the third venting sub-part 34, even if the first venting hole 31 is blocked, during electrolyte injection, after the leakage channel 43 is filled with electrolyte, the electrolyte flowing from the leakage channel 43 through the connecting channel 51 into the groove 35 can still enter the battery through the second venting holes 36. Furthermore, the electrolyte can be injected a greater distance along the length of the lower plastic part 100, thereby improving the uniformity of electrolyte wetting of the electrode assembly.

[0100] Figure 13 is a structural schematic diagram of an end cap assembly 200 according to an embodiment of this application. Figure 14 is an exploded structural schematic diagram of an end cap assembly 200 according to an embodiment of this application. Figure 15 is a structural schematic diagram of an end cap assembly 200 according to another view of an embodiment of this application. Figure 16 is an exploded structural schematic diagram of an end cap assembly 200 according to another view of an embodiment of this application.

[0101] Please refer to Figures 13 to 16. This application embodiment also provides an end cap assembly 200, which includes a top cap 210, an explosion-proof component 220, and a lower plastic component 100 as described in this application embodiment. The top cap 210 has an injection hole 211; the explosion-proof component 220 closes the explosion-proof hole 212; the lower plastic component 100 is located on one side of the upper top cap 210, and its first surface 10 faces the top cap 210; the perforated gap 45 is offset from the injection hole 211.

[0102] Understandably, the orthographic projection of the injection hole 211 on the second surface 20 is offset from the perforated gap 45. It is also understood that the perforated gap 45 is obscured by the top cover 210 along the arrangement direction of the top cover 210 and the lower plastic component.

[0103] It should be noted that when the end cap assembly 200 is applied to the energy storage device and electrolyte is injected, electrolyte is injected through the injection hole 211 of the top cover 210. The electrolyte flows through the injection hole 211, through the leakage tank 43 and the drain hole 44 in sequence into the energy storage device. When the electrolyte in the leakage tank 43 is full to the position of the connecting channel 51, the electrolyte also enters the energy storage device in sequence through the connecting channel 51, the groove 35, and the first vent hole 31 / second vent hole 36.

[0104] Optionally, the top cover 210 may be made of, but is not limited to, at least one of aluminum or aluminum alloy.

[0105] In this embodiment, the end cap assembly 200 of this application includes a top cap 210 and a lower plastic part 100. The lower plastic part 100 includes a venting part 30, a draining part 40, and a body part 50. The draining part 40 includes a bent and connected abutting part 41 and a surrounding part 42. The surrounding part 42 and the abutting part 41 form a draining groove 43 that penetrates the first surface 10. The draining part 40 also has a drain hole 44 that communicates with the draining groove 43. Thus, the lower plastic part 100 is applied to the end cap assembly of an energy storage device, and the energy storage device... When the top cover is bumped or shaken after electrolyte injection but before the injection hole is closed, the baffle 41 can prevent electrolyte from entering the leakage tank 43, thus reducing electrolyte spillage. Furthermore, when a small amount of electrolyte impacts the drain hole 44, most of it will be blocked by the enclosure 42 and returned to the energy storage device. Even if a small amount of electrolyte enters the leakage tank 43, since the drain hole 44 is also penetrated by the baffle 41, the electrolyte will fall back into the energy storage device under gravity, preventing liquid accumulation in the leakage tank 43. In addition, the baffle 41 can prevent the sealing nails of the end cap assembly from falling into the energy storage device, thus preventing temporary sealing failure. Weld slag from subsequent welding of the sealing aluminum nails could easily fall into the energy storage device, causing a short circuit. Furthermore, the drain hole 44 penetrates the enclosure 42. After the electrolyte enters the drain hole 44 from the drain tank 43, the electrolyte is sprayed further away, thereby 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. Moreover, the main body 50 is provided with a connecting channel 51 that connects the drain tank 43 to multiple first vent holes 31. When the electrolyte injection speed is fast and the injected electrolyte flow rate is large, and the drain hole 44 cannot keep up with the flow, the electrolyte will flow through the connecting channel 51 through the multiple first vent holes 31 and enter the interior of the energy storage device, thereby improving the injection rate and injection efficiency. Furthermore, by staggering the perforated slit 45 from the injection hole 211, when the end cap assembly 200 is applied to the energy storage device, and the energy storage device shakes, when the electrolyte impacts upward through the perforated slit 45, the electrolyte will also be blocked by the top cover 210 and returned to the leakage tank 43, and then flow back into the energy storage device through the drain hole 44. This can better prevent the electrolyte from overflowing, and also prevent the electrolyte from directly impacting the sealing nail in the injection hole, thus affecting the sealing performance of the sealing nail.

[0106] Optionally, the top cover 210 also has an injection hole 211; the orthographic projection of the explosion-proof component 220 on the second surface 20 at least partially overlaps with the orthographic projection of the vent 30 on the second surface 20, and the orthographic projection of the injection hole 211 on the second surface 20 at least partially overlaps with the orthographic projection of the leakage groove 43 on the second surface 20.

[0107] Understandably, the explosion-proof component 220 is provided correspondingly to the venting part 30, and the liquid injection hole 211 is provided correspondingly to the liquid leakage groove 43.

[0108] Optionally, the explosion-proof component 220 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 (understandably, the explosion-proof sheet 221 is connected to the top cover 210). 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.

[0109] 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.

[0110] 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 is partially inserted from the side of the lower plastic part 100 away from the top cover 210 into the lower plastic part 100 and the top cover 210, and is electrically connected to the positive electrode metal pressure block 230.

[0111] 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 is partially inserted from the side of the lower plastic part 100 away from the top cover 210 into the lower plastic part 100 and the top cover 210, and is electrically connected to the negative electrode metal pressure block 250.

[0112] 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 direction of the top cover 210. In the embodiment of this application, the liquid injection hole 211 is located between the explosion-proof assembly 220 and the positive electrode metal block 230.

[0113] 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.

[0114] Optionally, the end cap assembly 200 further includes a sealing nail 280, which passes through the injection hole 211 and the leakage groove 43, and is used to seal the injection hole 211 and the leakage groove 43 of the leakage part 40 after injection and before aluminum nail welding.

[0115] Please refer to Figure 15. In some embodiments, the number of drainage holes 44 is at least two, and the ratio of the total cross-sectional area S1 of the at least two drainage holes 44 to the cross-sectional area S2 of the injection hole 211, S1 / S2, is in the range of 0.1≤S1 / S2≤2.

[0116] Specifically, the ratio S1 / S2 of the sum of the cross-sectional areas S1 of at least two drainage holes 44 to the cross-sectional area S2 of the injection hole 211 can be, but is not limited to, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, etc.

[0117] In this embodiment, if the ratio S1 / S2 of the sum of the cross-sectional areas S1 of the at least two drain holes 44 to the cross-sectional area S2 of the injection hole 211 is too small, the electrolyte flow rate will be too slow when the end cap assembly 200 is applied to the energy storage device and injected, reducing the injection efficiency. In addition, it is easy for the electrolyte to splash out of the energy storage device during injection. If the ratio S1 / S2 of the sum of the cross-sectional areas S1 of the at least two drain holes 44 to the cross-sectional area S2 of the injection hole 211 is too large, the electrolyte is easy to pass through the drain holes 44 during the oscillation process when the end cap assembly 200 is applied to the energy storage device, 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 ratio of the cross-sectional area S1 of at least two drain holes 44 to the cross-sectional area S2 of the injection hole 211 is in the range of 0.1≤S1 / S2≤2, the end cap assembly 200 can be applied to an energy storage device, so that the energy storage device has a higher injection rate and better anti-backflow and anti-overflow effects.

[0118] Furthermore, the ratio S1 / S2 of the sum of the cross-sectional areas S1 of at least two drain holes 44 to the cross-sectional area S2 of the injection hole 211 is in the range of 0.1 ≤ S1 / S2 ≤ 1. This allows the end cap assembly 200 to be used in an energy storage device, resulting in a higher injection rate while also providing better backflow and overflow prevention.

[0119] Furthermore, the ratio S1 / S2 of the sum of the cross-sectional areas S1 of at least two drain holes 44 to the cross-sectional area S2 of the injection hole 211 is in the range of 0.1 ≤ S1 / S2 ≤ 0.5. This allows the end cap assembly 200 to achieve a higher injection rate while providing better backflow and overflow prevention when applied to an energy storage device.

[0120] Please refer to Figure 14. In some embodiments, the ratio of the cross-sectional area S3 of the connecting channel 51 to the cross-sectional area S2 of the injection hole 211, S3 / S2, is in the range of 0.5 ≤ S3 / S2 ≤ 4.

[0121] Specifically, the ratio S3 / S2 of the cross-sectional area S3 of the connecting channel 51 to the cross-sectional area S2 of the injection hole 211 can be, but is not limited to, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, etc.

[0122] In this embodiment, if the ratio S3 / S2 of the cross-sectional area S3 of the connecting channel 51 to the cross-sectional area S2 of the injection hole 211 is too small, the electrolyte flow rate will be too slow when the end cap assembly 200 is applied to the energy storage device and injected, reducing the injection efficiency. In addition, it is easy for the electrolyte to splash out of the energy storage device during injection. If the ratio S3 / S2 of the cross-sectional area S3 of the connecting channel 51 to the cross-sectional area S2 of the injection hole 211 is too large, the electrolyte will easily pass through the first vent hole 31 and the second vent hole 36 during the oscillation process when the end cap assembly 200 is applied to the energy storage device, and flow back to the leakage tank 43 through the connecting channel 51, causing overflow. This reduces the anti-overflow and anti-backflow effect of the lower plastic part 100 when the energy storage device shakes. When the ratio of the cross-sectional area S3 of the connecting channel 51 to the cross-sectional area S2 of the injection hole 211, S3 / S2, is in the range of 0.5≤S3 / S2≤4, the end cap assembly 200 can be applied to the energy storage device, so that the energy storage device has a higher injection rate and better anti-backflow and anti-overflow effects.

[0123] Furthermore, the ratio of the cross-sectional area S3 of the connecting channel 51 to the cross-sectional area S2 of the injection hole 211, S3 / S2, is in the range of 1 ≤ S3 / S2 ≤ 2. This allows the end cap assembly 200 to achieve a higher injection rate while also providing better backflow and overflow prevention when applied to an energy storage device.

[0124] Figure 17 is a structural schematic diagram of an energy storage device 300 according to an embodiment of this application. Figure 18 is a cross-sectional structural schematic diagram of an energy storage device 300 according to an embodiment of this application along the BB direction in Figure 17.

[0125] Please refer to Figures 17 and 18. This application embodiment also provides an energy storage device 300, which includes: the end cap assembly 200, the adapter piece (not shown), and the electrode assembly 310 described in this application embodiment. 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.

[0126] Optionally, the electrode assembly 310 includes a positive electrode 311, a diaphragm 312, and a negative electrode 313 stacked sequentially.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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

A closure assembly for an energy storage device, wherein, The end cover assembly comprises: a top cover having a liquid injection hole; a lower plastic part located on one side of the top cover, the lower plastic part having a first surface and a second surface arranged in opposite directions along the thickness direction, the first surface facing the lower plastic part, the lower plastic part comprising: an exhaust portion having a plurality of first exhaust holes arranged at intervals, the first exhaust holes penetrating the first surface and the second surface respectively; a liquid leakage portion arranged at intervals with the exhaust portion, the liquid leakage portion comprising a blocking portion and a surrounding portion connected by bending, the surrounding portion being arranged around the outer periphery of the blocking portion, the blocking portion and the surrounding portion enclosing a liquid leakage groove penetrating the first surface, the liquid leakage portion further having a liquid discharge hole, the liquid discharge hole being arranged close to the blocking portion and communicating with the liquid leakage groove, the liquid discharge hole penetrating the blocking portion and the surrounding portion respectively, the blocking portion and the surrounding portion having a hollow gap between them in the orthographic projection of the second surface, the hollow gap being arranged staggered with the liquid injection hole; and a body portion connecting the exhaust portion and the liquid leakage portion respectively, the body portion being arranged around the outer periphery of the liquid leakage portion at least and connecting one end of the surrounding portion away from the blocking portion, the body portion having a communication passage penetrating the first surface, the communication passage communicating the plurality of first exhaust holes and the liquid leakage groove respectively. According to the end cover assembly of claim 1, the hollow gap has a range of 0.01mm≤d≤2.8mm. The end cap assembly of claim 1, wherein The liquid leakage portion and the exhaust portion are arranged along the length direction of the lower plastic part, the number of the liquid discharge holes is two, and the two liquid discharge holes are arranged along the width direction of the lower plastic part. The end cap assembly of claim 1, wherein The cross-sectional area A of the drain hole ranges from 0.3 mm 2 ≤ A ≤ 3 mm 2 . The end cap assembly of claim 1, wherein The body portion has a first side wall, a bottom wall and a second side wall connected by bending on one side of the communication passage, the first side wall and the second side wall being arranged along the width direction of the lower plastic part; The lower plastic part further comprises a first blocking member and a second blocking member, the first blocking member being located on the bottom wall, one end of the first blocking member being connected to the first side wall and the other end thereof being away from the first side wall, the end of the first blocking member connected to the first side wall being closer to the liquid leakage groove than the end of the first blocking member away from the first side wall; The second blocking member is located on the bottom wall, one end of the second blocking member being connected to the second side wall and the other end thereof being away from the second side wall, the end of the second blocking member connected to the second side wall being closer to the liquid leakage groove than the end of the second blocking member away from the second side wall. The end cap assembly of claim 5, wherein The angle α between the first blocking member and the first side wall has a range of 100°≤α≤150°, and the angle β between the second blocking member and the second side wall has a range of 100°≤β≤150°. The end cap assembly of claim 5, wherein Along the length direction of the lower plastic part, the first blocking member and the second blocking member partially overlap, and the length L of the overlapping part of the first blocking member and the second blocking member has a range of 0.5mm≤L≤5mm. The end cap assembly of claim 5, wherein, The body portion protrudes from the second surface at the position corresponding to the communication passage. The end cap assembly of claim 1, wherein The exhaust part comprises a first exhaust subpart, a second exhaust subpart and a third exhaust subpart connected in sequence and bent, the first exhaust subpart and the third exhaust subpart are located on the same side of the second exhaust subpart, the first exhaust subpart, the second exhaust subpart and the third exhaust subpart enclose a groove facing away from the second surface, and the groove communicates with the communication channel; the body part comprises a first body subpart and a second body subpart, the first body subpart and the second body subpart are located on opposite sides of the exhaust part, the first body subpart is connected to one end of the first exhaust subpart away from the second exhaust subpart and is arranged around the outer periphery of the liquid leakage part, and the first body subpart has the communication channel; the second body subpart is connected to one end of the third exhaust subpart away from the second exhaust subpart; the second exhaust subpart has a plurality of first exhaust holes, and the plurality of first exhaust holes communicate with the groove; the first exhaust subpart and the third exhaust subpart each have a plurality of second exhaust holes arranged at intervals, and the plurality of second exhaust holes communicate with the groove. The end cap assembly of claim 1, wherein The number of the liquid discharge holes is at least two, and the ratio S1 / S2 of the sum S1 of the cross-sectional areas of the at least two liquid discharge holes to the cross-sectional area S2 of the liquid injection hole is in the range of 0.1≤S1 / S2≤2. The end cap assembly of claim 1, wherein The ratio S3 / S2 of the cross-sectional area S3 of the communication channel to the cross-sectional area S2 of the liquid injection hole is in the range of 0.5≤S3 / S2≤4. An energy storage device, wherein, The electrode assembly comprises: The end cover assembly of any one of claims 1-11; The adapter plate is arranged on the side of the lower plastic part away from the top cover, one end of the adapter plate is electrically connected to the end cover assembly; And The electrode assembly is arranged on the side of the adapter plate away from the end cover assembly, and the electrode assembly is electrically connected to the end of the adapter plate away from the end cover assembly.

Images