Lower plastic component, end cover assembly, energy storage device, and electric apparatus

Abstract

Provided in the present application are a lower plastic component, an end cover assembly, an energy storage device and an electric apparatus. The yield of the lower plastic component can be improved, which is conducive to improving the production efficiency of the energy storage device, and it can also be ensured that the lower plastic component has high overall structural strength, thereby preventing the deformation of the lower plastic component, and ensuring the good usage reliability of the energy storage device. The lower plastic component comprises a first lower plastic part and a second lower plastic part. In the direction of the length of the lower plastic component, the first lower plastic part and the second lower plastic part are arranged in sequence. The length l1 of the first lower plastic part is greater than the length l2 of the second lower plastic part. An extension portion is provided at one end of the second lower plastic part facing the first lower plastic part, and the extension portion is located on one side of the first lower plastic part in the direction of the thickness thereof and supports the first lower plastic part.

Description

Plastic components, end cap assemblies, energy storage devices and electrical equipment

[0001] This application claims priority to Chinese Patent Application No. 202411737643.4, filed on November 29, 2024, entitled "Underlying Plastic, End Cap Assembly, Energy Storage Device and Electrical Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of energy storage technology, and in particular to a lower plastic, an end cap assembly, an energy storage device, and an electrical device. Background Technology

[0003] Secondary batteries and other energy storage devices are widely used as the main power source for electrical equipment due to their recyclability. As the demand for energy storage devices gradually increases, the performance requirements for them are also rising. Currently, large-capacity secondary batteries are increasingly favored by the market because they can provide longer energy reserves. However, large-capacity secondary batteries are longer, and their corresponding matching lower plastic inserts are relatively narrow. Uneven cooling during injection molding of the lower plastic insert can easily occur, leading to warping and difficulty in controlling dimensional accuracy, resulting in a lower yield rate and reduced production efficiency for large-capacity secondary batteries. Summary of the Invention

[0004] This application provides an end cap assembly, an energy storage device, and an electrical device, which can improve the sealing performance of the end cap assembly and prevent electrolyte from entering the gap between the cap body and the welding ring, thereby helping to improve the safety and reliability of the energy storage device.

[0005] This application provides a lower plastic, an end cap assembly, an energy storage device, and an electrical device, which can improve the yield of the lower plastic, help improve the production efficiency of the energy storage device, ensure the overall structural strength of the lower plastic, prevent deformation of the lower plastic, and ensure the reliable use of the energy storage device.

[0006] In a first aspect, this application provides a lower plastic sheet for an energy storage device. The lower plastic sheet includes a first lower plastic sheet and a second lower plastic sheet, which are arranged sequentially along the length direction of the lower plastic sheet. The length l1 of the first lower plastic sheet is greater than the length l2 of the second lower plastic sheet. The second lower plastic sheet has a protruding portion at one end facing the first lower plastic sheet. The protruding portion is located on one side of the thickness direction of the first lower plastic sheet and supports the first lower plastic sheet.

[0007] Secondly, this application also provides an end cap assembly, including a cover plate, a first pole post unit, a second pole post unit, and a lower plastic as described in any of the preceding claims. The first lower plastic and the second lower plastic are both located on one side of the cover plate in the thickness direction. The first lower plastic has a first mounting hole that penetrates the first lower plastic along its thickness direction. The second lower plastic has a second mounting hole that penetrates the second lower plastic along its thickness direction. The cover plate has a first assembly hole and a second assembly hole that penetrate the cover plate along its thickness direction and are spaced apart from each other. The first assembly hole communicates with the first mounting hole, and the second assembly hole communicates with the second mounting hole. The first pole post unit passes through the first mounting hole and the first assembly hole, and the second pole post unit passes through the second mounting hole and the second assembly hole.

[0008] Thirdly, this application also provides an energy storage device, including a housing, a battery cell, and an end cap assembly as described above. The housing has an opening and a receiving cavity, the opening communicating with the receiving cavity, the battery cell being received in the receiving cavity, and the end cap assembly being mounted on the housing and closing the opening.

[0009] Fourthly, this application also provides an electrical device, including an energy storage device as described in any of the preceding claims, wherein the energy storage device supplies power to the electrical device.

[0010] In the technical solution provided in this application, by providing a protrusion at one end of the second lower plastic piece facing the first lower plastic piece, and positioning the protrusion on one side of the thickness direction of the first lower plastic piece, the second lower plastic piece, being shorter in length than the first, has a shorter lever arm and is less prone to deformation. The protrusion provides support to the first lower plastic piece, making it less likely to bend or deform towards the energy storage device's cell. This ensures that the lower plastic piece as a whole is less prone to deformation, contributing to good overall reliability of the end cap assembly and thus improving the reliability of the energy storage device. Furthermore, the separate molding of the first and second lower plastic pieces reduces the difficulty of lower plastic piece preparation and increases the manufacturing yield, thereby improving the production efficiency of the energy storage device. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0012] Figure 1 is a schematic diagram of the energy storage device provided in an embodiment of this application;

[0013] Figure 2 is a schematic cross-sectional view of the energy storage device shown in Figure 1 after it is cut along point AA.

[0014] Figure 3 is a structural schematic diagram of the end cap assembly in the energy storage device shown in Figure 1;

[0015] Figure 4 is an exploded structural diagram of the end cap assembly shown in Figure 3;

[0016] Figure 5 is a schematic diagram of the lower plastic structure in the end cap assembly shown in Figure 4;

[0017] Figure 6 is a schematic diagram of the structure of the plastic shown in Figure 5 from another angle;

[0018] Figure 7 is a schematic diagram of the structure of the lower plastic section cut along BB as shown in Figure 5;

[0019] Figure 8 is an enlarged schematic diagram of region C in Figure 7;

[0020] Figure 9 is a schematic diagram of the cover plate in the end cap assembly shown in Figure 3;

[0021] Figure 10 is a schematic diagram of the flow of internal gas when the energy storage device shown in Figure 2 experiences thermal runaway.

[0022] The names corresponding to the reference numerals in the figures are as follows: Energy storage device 100, housing 110, end cap assembly 120, battery cell 130, receiving cavity 110a, lower plastic 10, cover plate 20, explosion-proof valve 30, first pole unit 40, second pole unit 50, first pin 60, second pin 70, first lower plastic 11, second lower plastic 12, first main body 11a, first boss 14, second boss 13, protective cover 16, first surface 111, second surface 112, explosion-proof fence 101, liquid inlet 106, first mounting hole 107, first mounting groove 102, first vent 103, third vent 1 31, First air guide channel 141, baffle 161, connecting plate 162, liquid flow hole 163, second main body 12a, third boss 15, third surface 121, fourth surface 122, protrusion 12b, connecting part 12c, second mounting hole 108, second vent hole 105, second mounting groove 104, second air guide channel 151, liquid injection hole 201, explosion-proof hole 202, first assembly hole 203, second assembly hole 204. Detailed Implementation

[0023] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0024] Please refer to Figures 1 and 2. Figure 1 is a structural schematic diagram of the energy storage device 100 provided in an embodiment of this application, and Figure 2 is a cross-sectional structural schematic diagram of the energy storage device 100 shown in Figure 1 after being cut along line AA. Here, "cut along line AA" means cutting along the plane containing line AA, and similar descriptions thereafter can be understood in the same way. Furthermore, for ease of description, the length direction of the energy storage device 100 is defined as the X-axis direction, the width direction as the Y-axis direction, and the height direction as the Z-axis direction. The X-axis, Y-axis, and Z-axis directions are all perpendicular to each other.

[0025] In this embodiment, the energy storage device 100 includes a housing 110, an end cap assembly 120, and a battery cell 130. The housing 110 has an opening (not shown) and a receiving cavity 110a, the opening communicating with the receiving cavity 110a. The battery cell 130 is housed in the receiving cavity 110a. The receiving cavity 110a also houses an electrolyte, in which the battery cell 130 is immersed. The end cap assembly 120 is mounted on one side of the housing 110 in the height direction (Z-axis direction shown in the figure) of the energy storage device 100 and closes the opening. Exemplarily, the energy storage device 100 is a prismatic battery. The width direction of the energy storage device 100 is parallel to the X-axis direction, the length direction is parallel to the Y-axis direction, and the height direction is parallel to the Z-axis direction. In other embodiments, the energy storage device 100 may also be a cylindrical battery or other types of batteries.

[0026] Please refer to Figures 2, 3 and 4. Figure 3 is a structural schematic diagram of the end cap assembly 120 in the energy storage device 100 shown in Figure 1, and Figure 4 is an exploded structural schematic diagram of the end cap assembly 120 shown in Figure 3.

[0027] The end cap assembly 120 includes a lower plastic part 10, a cover plate 20, an explosion-proof valve 30, a first pole unit 40, a second pole unit 50, a first pin 60, and a second pin 70. The lower plastic part 10 is mounted on one side of the cover plate 20 in the thickness direction. The first pole unit 40 and the second pole unit 50 of the explosion-proof valve 30 are both mounted on the cover plate 20. Along the length of the energy storage device 100, the first pole unit 40 and the second pole unit 50 are located on opposite sides of the explosion-proof valve 30. The first pin 60 is electrically connected to the first pole unit 40. The second pin 70 is electrically connected to the second pole unit 50.

[0028] Please refer to Figures 5 to 7. Figure 5 is a structural schematic diagram of the lower plastic 10 in the end cap assembly 120 shown in Figure 4. Figure 6 is a structural schematic diagram of the lower plastic 10 shown in Figure 5 from another angle. Figure 7 is a structural schematic diagram of the lower plastic 10 shown in Figure 5 cut along BB.

[0029] In this embodiment, the lower plastic 10 includes a first lower plastic 11 and a second lower plastic 12. Along the length direction of the lower plastic 10 (the X-axis direction in the figure), the first lower plastic 11 and the second lower plastic 12 are arranged sequentially. Exemplarily, both the first lower plastic 11 and the second lower plastic 12 are formed by injection molding. With this arrangement, the first lower plastic 11 and the second lower plastic 12 are formed separately, which reduces the manufacturing difficulty of the lower plastic 10, thereby helping to improve the production efficiency of the energy storage device 100. Furthermore, along the thickness direction of the energy storage device, the surfaces of the first lower plastic 11 and the second lower plastic 12 facing away from the cover plate 20 are both positioned opposite to the battery cell 130.

[0030] In this embodiment, the ratio of the length L1 to the width W1 of the lower plastic 10 is greater than 4. Specifically, the length l1 of the first lower plastic 11 is greater than the length l2 of the second lower plastic 12. That is, the lever arm of the first lower plastic 11 is greater than the lever arm of the second lower plastic 12. The ratio of the length l1 of the first lower plastic 11 to the length l2 of the second lower plastic 12 is 1.5 ≤ l1 / l2 ≤ 2. This configuration effectively improves the feasibility of prototyping the first lower plastic 11 during the production process, facilitating its injection molding.

[0031] In this embodiment, the first lower plastic part 11 includes a first main body 11a, a first boss 14, a second boss 13, and a protective cover 16. The first boss 14 and the second boss 13 are both fixedly connected to one side of the first main body 11a in the thickness direction. The first main body 11a includes a first surface 111 and a second surface 112. Along the thickness direction of the first main body 11a, the first surface 111 and the second surface 112 are arranged opposite to each other. The first main body 11a also includes an explosion-proof fence 101, which penetrates the first surface 111 and the second surface 112. The first main body 11a is also provided with a liquid inlet 106, a first mounting hole 107, a first mounting groove 102, and a first vent hole 103. The liquid inlet 106, the first mounting hole 107, and the first vent hole 103 all penetrate the first surface 111 and the second surface 112 and are spaced apart from each other. Specifically, along the length of the lower plastic 10, the liquid inlet 106 and the first mounting hole 107 are both located on the side of the explosion-proof fence 101 away from the second lower plastic 12, and are spaced apart from the explosion-proof fence 101. Among them, along the length of the lower plastic 10, the liquid inlet 106 is located between the explosion-proof fence 101 and the first mounting hole 107.

[0032] In this embodiment, there are multiple first vent holes 103. The multiple first vent holes 103 are arranged in an array and spaced apart from each other. Among them, along the length direction of the lower plastic 10, a portion of the multiple first vent holes 103 are located on the side of the explosion-proof fence 101 opposite to the liquid inlet hole 106, and another portion of the multiple first vent holes 103 are located between the explosion-proof fence 101 and the first mounting hole 107.

[0033] The opening of the first mounting groove 102 is located on the first surface 111 of the first lower plastic 11. Specifically, the first mounting groove 102 is recessed from the first surface 111 toward the second surface 112. In this embodiment, the first mounting groove 102 is arranged around the periphery of the first mounting hole 107 and is spaced apart from the first vent hole 103. The first mounting groove 102 is used to mount the first pin 60.

[0034] In this embodiment, the first boss 14, the second boss 13, the protective cover 16, and the first main body 11a are integrally formed. For example, the first boss 14, the second boss 13, the protective cover 16, and the first main body 11a can be integrally formed using injection molding. Specifically, the first boss 14, the second boss 13, and the protective cover 16 are all fixedly connected to the first surface 111 of the first main body 11a, and are spaced apart from each other, and are also spaced apart from the liquid inlet hole 106. The first boss 14 and the second boss 13 both protrude relative to the first surface 111 and extend along the width direction of the lower plastic 10. Along the length direction of the lower plastic 10, the first boss 14 and the second boss 13 are both located on the side of the first mounting hole 107 facing the second lower plastic 12, and are respectively located on opposite sides of the liquid inlet hole 106. Along the height direction of the energy storage device 100, the first boss 14 and the second boss 13 are both positioned opposite the battery cell 130. The first protrusion 14 and the second protrusion 13 are both used to abut against the battery cell 130 of the energy storage device 100. In addition, the surface of the first protrusion 14 facing away from the first surface 111 is flush with the surface of the second protrusion 13 facing away from the first surface, so as to ensure that both the first protrusion 14 and the second protrusion 13 can abut against the battery cell 130 smoothly.

[0035] Specifically, along the length of the lower plastic 10, the first boss 14 is located between the first mounting hole 107 and the liquid inlet hole 106, and is spaced apart from both the first mounting hole 107 and the liquid inlet hole 106. In other words, along the length of the lower plastic 10, multiple first vent holes 103 are located on the side of the first boss 14 facing away from the first mounting hole 107. With this arrangement, the first boss 14 can be prevented from obstructing the subsequent installation of the first pin 60, preventing interference between the first boss 14 and the first pin 60, and ensuring that the end cap assembly 120 can be successfully assembled.

[0036] In this embodiment, the first protrusion 14 is provided with a first air guide channel 141. The first air guide channel 141 extends through the first protrusion 14 along the length direction of the lower plastic 10. For example, there are multiple first air guide channels 141. The multiple first air guide channels 141 are spaced apart along the width direction of the lower plastic 10.

[0037] Along the length of the lower plastic 10, the second protrusion 13 is located on the side of the liquid inlet 106 facing the second lower plastic 12, and is spaced apart from the first protrusion 14, and is fixedly connected to the explosion-proof fence 101. With this configuration, when the energy storage device 100 experiences thermal runaway, the second protrusion 13 can abut against the upwardly moving battery cell 130, ensuring unobstructed venting between the explosion-proof fence 101 and the battery cell 130, and guaranteeing good venting performance. Furthermore, along the length of the lower plastic 10, the width of the second protrusion 13 is greater than the width of the first protrusion 14. In some other embodiments, the width of the second protrusion 13 may be less than or equal to the width of the first protrusion 14; the embodiments of this application do not strictly limit this.

[0038] The second protrusion 13 is provided with a third vent 131. The third vent 131 penetrates the second protrusion 13 along its thickness direction, and also penetrates the first surface 111 and the second surface 112 of the first main body 11a, and communicates with the explosion-proof fence 101. In this embodiment, there are multiple third vents 131. Multiple third vents 131 are spaced apart along the width direction of the lower plastic 10.

[0039] In this embodiment, the lower plastic 10 is divided into a first lower plastic 11 and a second lower plastic 12. A first protrusion 14 and a second protrusion 13 are provided on the first lower plastic 11. When the energy storage device 100 is injected with electrolyte, the first protrusion 14 and the second protrusion 13 of the first lower plastic 11 abut against the battery cell 130 under the impact force of the high-speed flowing electrolyte. At this time, the battery cell 130 can provide support for the first lower plastic 11, thereby effectively improving the deformation problem of the first lower plastic 11 caused by the high-speed impact of the electrolyte, and thus helping to improve the reliability of the energy storage device 100.

[0040] A protective cover 16 is provided over the liquid inlet 106 of the first main body 11a. In this embodiment, the protective cover 16 includes a baffle 161 and a connecting plate 162. Along the thickness direction of the first lower plastic 11, the baffle 161 is spaced apart from the first main body 11a. The connecting plate 162 is fixedly connected between the first main body 11a and the baffle 161. The connecting plate 162 is provided with two liquid outlet holes 163, both of which penetrate the connecting plate 162 along its thickness direction. Along the width direction of the lower plastic 10, the two liquid outlet holes 163 are spaced apart and opposite to each other.

[0041] During the electrolyte filling process of the energy storage device 100, the electrolyte enters the protective cover 16 through the inlet hole 106 of the first main body 11a, and then flows into the receiving cavity 110a through the outlet hole 163 of the protective cover 16. By setting the protective cover 16 at the position where the inlet hole 106 is provided on the first lower plastic 11, and setting two outlet holes 163 in the width direction (Y-axis direction in the figure) of the protective cover 16, when the electrolyte flows into the receiving cavity 110a from the outlet holes 163, the electrolyte only impacts the housing 110 of the energy storage device 100 from both sides in the width direction of the lower plastic 10, thereby preventing the electrolyte from directly impacting the battery cell 130, which helps to reduce the impact of the electrolyte on the electrode of the battery cell 130, and thus helps to ensure the better reliability of the energy storage device 100.

[0042] Furthermore, in actual production, the energy storage device 100 is usually transported along its length. By setting a protective cover 16 and providing a liquid flow hole 163 in the width direction of the protective cover 16, the electrolyte in the receiving cavity 110a can be prevented from overflowing due to the shaking of the energy storage device 100 in the length direction during transportation. This can prevent the instability of the cell performance of the energy storage device 100 caused by the instantaneous reduction of electrolyte, and thus help ensure the good reliability of the energy storage device 100.

[0043] Please continue to refer to Figures 6 to 8. Figure 8 is an enlarged schematic diagram of region C in Figure 7.

[0044] The second lower plastic 12 includes a second main body portion 12a and a third boss 15, the third boss 15 being fixedly connected to one side of the second main body portion 12a in the thickness direction. The second main body portion 12a and the first main body portion 11a are arranged sequentially along the length direction of the lower plastic 10. The length l1 of the first main body portion 11a is greater than the length l2 of the second main body portion 12a.

[0045] In this embodiment, the second main body 12a includes a third surface 121 and a fourth surface 122. Along the thickness direction of the second main body 12a, the third surface 121 and the fourth surface 122 are arranged opposite to each other. The third surface 121 and the first surface 111 of the first main body 11a have the same orientation, and together with the first surface 111, they form the bottom surface of the lower plastic 10. The fourth surface 122 and the second surface 112 of the first lower plastic 11 have the same orientation, and together with the second surface 112, they form the top surface of the lower plastic 10.

[0046] The second main body 12a is further provided with a second mounting hole 108, a second vent hole 105, and a second mounting groove 104. The second mounting hole 108 and the second vent hole 105 both penetrate the third surface 121 and the fourth surface 122, and are spaced apart from each other. Along the length of the lower plastic 10, the second vent hole 105 is located on the side of the second mounting hole 108 facing the first main body 11a of the first lower plastic 11, and is spaced apart from the second mounting hole 108. For example, there are multiple second vent holes 105. The multiple second vent holes 105 are arranged in an array and are spaced apart from each other. The opening of the second mounting groove 104 is located on the third surface 121 of the second lower plastic 12. Specifically, the second mounting groove 104 is recessed from the third surface 121 towards the fourth surface 122. In this embodiment, the second mounting groove 104 is arranged around the periphery of the second mounting hole 108 and is spaced apart from the second vent hole 105. The second mounting groove 104 is used to mount the second pin 70.

[0047] In this embodiment, the second lower plastic 12 further includes a protrusion 12b and a connecting portion 12c. The connecting portion 12c is connected to the end of the second main body 12a facing the first main body 11a and intersects with the second main body 12a. The protrusion 12b is located at the end of the second lower plastic 12 facing the first lower plastic 11. In other words, the end of the second lower plastic 12 facing the first lower plastic 11 has a protrusion 12b. The protrusion 12b is located on one side of the thickness direction of the first lower plastic 11 and supports the first lower plastic 11. That is, the protrusion 12b is located on the side of the first lower plastic 11 facing the battery cell 130. Specifically, the protrusion 12b is fixedly connected to the end of the connecting portion 12c away from the second main body 12a, intersects with the connecting portion 12c, and supports the first main body 11a of the first lower plastic 11.

[0048] It is understandable that by providing a protrusion 12b at one end of the second main body portion 12a of the second lower plastic 12 toward the first main body portion 11a of the first lower plastic 11, and positioning the protrusion 12b on one side of the thickness direction of the first main body portion 11a of the first lower plastic 11, since the length of the second lower plastic 12 is less than the length of the first lower plastic 11, the lever arm of the second lower plastic 12 is shorter and less prone to deformation. The protrusion 12b can provide support for the first lower plastic 11, making it less likely for the first lower plastic 11 to bend and deform toward the direction of the cell 130 of the energy storage device 100. This makes it easier for the lower plastic 10 as a whole to not deform, which helps to ensure the overall reliability of the end cap assembly 120 and thus improves the reliability of the energy storage device 100.

[0049] Furthermore, since the ratio of the length l1 of the first lower plastic 11 to the length l2 of the second lower plastic 12 is 1.5≤l1 / l2≤2, the first lower plastic 11 and the second lower plastic 12 have a suitable length ratio, which allows the protruding part 12b to press on the first lower plastic 11 and provide better support for the first lower plastic 11. This makes the first lower plastic 11 less likely to bend and deform towards the battery cell 130 side, thereby making the lower plastic 10 less prone to deformation as a whole, which helps to ensure the overall reliability of the end cap assembly 120.

[0050] The third protrusion 15 is fixedly connected to the third surface 121 and protrudes relative to the third surface 121, serving to abut against the battery cell 130 of the energy storage device 100. Along the length of the lower plastic 10, the third protrusion 15 is located on the side of the second mounting hole 108 facing the first main body 11a, and is spaced apart from the second mounting hole 108. Specifically, the third protrusion 15 is located between the second mounting groove 104 and the second vent hole 105, and is spaced apart from both the second mounting groove 104 and the second vent hole 105. In other words, along the length of the lower plastic 10, the second vent hole 105 of the second lower plastic 12 is located on the side of the third protrusion 15 facing away from the second mounting hole 108, and is spaced apart from the third protrusion 15. This arrangement prevents the third protrusion 15 from obstructing the subsequent installation of the second pin 70, prevents interference between the third protrusion 15 and the second pin 70, and ensures that the end cap assembly 120 can be successfully assembled. Furthermore, along the length of the lower plastic 10, the width of the third boss 15 is equal to the width of the first boss 14 and less than the width of the second boss 13. In some other embodiments, the widths of the first boss 14, the second boss 13, and the third boss 15 may also be the same, and the embodiments of this application do not impose strict limitations on this.

[0051] Furthermore, the extension direction of the protrusion 12b is parallel to the length direction of the first main body portion 11a of the first lower plastic 11. The distance between the surface of the protrusion 12b facing the first main body portion 11a of the first lower plastic 11 and the fourth surface 122 of the second main body portion 12a is equal to the thickness of the first main body portion 11a. It is understood that when the first lower plastic 11 and the second lower plastic 12 are assembled, this arrangement ensures that the protrusion 12b provides good support for the first lower plastic 11, preventing deformation and sinking of the first lower plastic 11 during installation. Simultaneously, it also ensures that the second surface 112 of the first main body portion 11a and the fourth surface 122 of the second main body portion 12a are flush, avoiding interference with the subsequent assembly between the cover plate 20 and the lower plastic 10, thereby helping to ensure good assembly reliability between the lower plastic 10 and the cover plate 20.

[0052] In this embodiment, the third protrusion 15 is provided with a second air guide channel 151. The second air guide channel 151 extends through the third protrusion 15 along the length of the lower plastic 10. For example, there are multiple second air guide channels 151. Multiple second air guide channels 151 are spaced apart along the width of the lower plastic 10.

[0053] Understandably, when thermal runaway occurs in the energy storage device 100, the battery cell 130 will move and arch towards the end cap assembly 120 under the influence of airflow. At this time, the first protrusion 14, the second protrusion 13, and the third protrusion 15 of the lower plastic 10 abut against the battery cell 130, which can limit the battery cell 130 and prevent it from shaking violently within the housing 110. This prevents the battery cell 130 from becoming loose or its tabs from being torn, thereby preventing structural damage to the battery cell 130 and improving its safety performance, ensuring the reliability and safety of the energy storage device 100. Simultaneously, the battery cell 130 can also provide support for the first lower plastic 11 and the second lower plastic 12, helping to mitigate deformation issues of the first lower plastic 11 and the second lower plastic 12.

[0054] Please refer to Figures 2 and 9. Figure 9 is a structural schematic diagram of the cover plate 20 in the end cap assembly 120 shown in Figure 3.

[0055] In this embodiment, the cover plate 20 is provided with an injection hole 201, an explosion-proof hole 202, a first assembly hole 203, and a second assembly hole 204. The explosion-proof hole 202, the injection hole 201, the first assembly hole 203, and the second assembly hole 204 all penetrate the cover plate 20 along its thickness direction and are spaced apart from each other. Specifically, along the length direction of the cover plate 20, the explosion-proof hole 202 is located in the middle of the cover plate 20 and communicates with the explosion-proof fence 101 of the first lower plastic 11. The explosion-proof hole 202 can communicate with the interior of the energy storage device 100 through the explosion-proof fence 101.

[0056] Along the length of the cover plate 20, the first mounting hole 203 and the second mounting hole 204 are located on opposite sides of the explosion-proof hole 202. The first mounting hole 203 communicates with the first mounting hole 107 of the first lower plastic 11 to facilitate the installation of the first pole post unit 40. The second mounting hole 204 communicates with the second mounting hole 108 of the second lower plastic 12 to facilitate the installation of the second pole post unit 50.

[0057] Along the length of the cover plate 20 (X-axis direction in the figure), the injection hole 201 is located between the explosion-proof hole 202 and the first assembly hole 203. The injection hole 201 is connected to the liquid inlet hole 106 of the first lower plastic 11. Electrolyte can be injected into the receiving cavity 110a of the housing 110 (as shown in Figure 2) of the housing 110 in sequence through the injection hole 201 of the cover plate 20 and the liquid inlet hole 106 of the first lower plastic 11 to realize the filling of electrolyte into the energy storage device 100.

[0058] Furthermore, the ratio between the length L2 and the width W2 of the cover plate 20 is greater than 4. With this configuration, when the energy storage device 100 experiences thermal runaway, the cover plate 20 can bend and deform to create a gap between the cover plate 20 and the lower plastic 10. This provides a gas flow path for the thermal runaway gas inside the energy storage device 100, thereby improving the exhaust efficiency of the thermal runaway gas and ensuring timely valve opening and pressure relief when the energy storage device 100 experiences thermal runaway, thus enhancing the safety performance of the energy storage device 100.

[0059] Please refer to Figure 3 again. The explosion-proof valve 30 is installed in the explosion-proof hole 202 and fixedly connected to the hole wall of the explosion-proof hole 202. For example, the explosion-proof valve 30 can be fixedly connected to the hole wall of the explosion-proof hole 202 by welding, so as to be installed in the explosion-proof hole 202. It is understood that since the explosion-proof hole 202 connects the inside and outside of the energy storage device 100, when the gas pressure inside the energy storage device 100 is too high, the explosion-proof valve 30 will rupture under the action of gas pressure. The gas inside the energy storage device 100 can be discharged to the outside of the energy storage device 100 in a timely manner through the third vent hole 131 of the second protrusion 13, the explosion-proof fence 101, and the explosion-proof hole 202 of the cover plate 20, so as to avoid the explosion of the energy storage device 100 and improve the reliability of the energy storage device 100.

[0060] Please refer to Figure 2 again. In this embodiment, the first terminal unit 40 passes through the first mounting hole 107 of the first lower plastic 11 and the first assembly hole 203 of the cover plate 20. For example, the first terminal unit 40 is a positive terminal unit and is electrically connected to the positive electrode tab of the battery cell 130. The second terminal unit 50 passes through the second mounting hole 108 of the second lower plastic 12 and the second assembly hole 204 of the cover plate 20. For example, the second terminal unit 50 is a negative terminal unit and is electrically connected to the negative electrode tab of the battery cell 130.

[0061] Understandably, by dividing the lower plastic 10 into a first lower plastic 11 and a second lower plastic 12, the problem of difficulty in controlling the injection molding precision of the lower plastic 10 due to its elongated shape can be solved, and the difference between the actual length and the target length of the lower plastic 10 can be reduced. When the lower plastic 10 is assembled with the first pole post unit 40 and the second pole post unit 50, since the first lower plastic 11 and the second lower plastic 12 of the lower plastic 10 are molded separately, the middle of the lower plastic 10 will not bulge or deform after installation, thus ensuring that the first pole post unit 40 and the second pole post unit 50 can be smoothly assembled with the lower plastic 10. Meanwhile, since the second lower plastic 12 has a protrusion 12b at one end facing the first lower plastic 11, the protrusion 12b can provide support for the end of the first lower plastic 11 that is away from the first pole unit 40, preventing the end of the first lower plastic 11 away from the first pole unit 40 from deforming and sinking. It can also reserve space for size adjustment when installing the lower plastic 10. The length of the lower plastic 10 after installation can be controlled according to the overlap length between the protrusion and the first lower plastic 11, thereby ensuring that the first lower plastic 11 is not easily deformed as a whole, ensuring that the end cap assembly 120 has good overall reliability, and thus improving the reliability of the energy storage device 100.

[0062] The first pin 60 is mounted in the first mounting groove 102 of the first lower plastic 11 and electrically connected to the first terminal unit 40. Specifically, one end of the first pin 60 is electrically connected to the first terminal unit 40, and the other end is electrically connected to the positive electrode tab of the battery cell 130. For example, the first pin 60 can be electrically connected to the first terminal unit 40 and / or the positive electrode tab of the battery cell 130 by soldering. The second pin 70 is mounted in the second mounting groove 104 of the second lower plastic 12 and electrically connected to the second terminal unit 50. Specifically, one end of the second pin 70 is electrically connected to the second terminal unit 50, and the other end is electrically connected to the negative electrode tab of the battery cell 130. For example, the second pin 70 can be electrically connected to the second terminal unit 50 and / or the negative electrode tab of the battery cell 130 by soldering.

[0063] Please refer to Figures 2 and 10. Figure 10 is a schematic diagram of the flow of internal gas when thermal runaway occurs in the energy storage device 100 shown in Figure 2.

[0064] In this embodiment, when thermal runaway occurs in the energy storage device 100, a portion of the gas inside the energy storage device 100 reaches the top of the battery cell 130 through the gap between the first pin 60 and the battery cell 130 and the gap between the second pin 70 and the battery cell 130. It then passes through the first venting channel 141 of the first protrusion 14, the explosion-proof fence 101, and the second venting channel 151 of the third protrusion 15, and reaches the bottom of the explosion-proof valve 30 through the explosion-proof hole 202 of the cover plate 20. Simultaneously, the cover plate 20 arches under the action of the thermal runaway gas, creating a gap between the cover plate 20 and the lower plastic 10. At this time, the gas from the energy storage device 100 reaching the top of the battery cell 130 can also reach the bottom of the explosion-proof valve 30 through multiple arrayed first vent holes 103, multiple arrayed second vent holes 105, and multiple third vent holes 131.

[0065] With this configuration, a three-dimensional air passage can be formed in the lower plastic 10 to guide the thermal runaway gas inside the energy storage device 100 to flow rapidly to the area below the explosion-proof valve 30. This helps to improve the exhaust efficiency of the thermal runaway gas, allowing it to quickly reach the area below the explosion-proof valve 30. This ensures that the valve can be opened in time to release pressure when the energy storage device 100 experiences thermal runaway, preventing the energy storage device 100 from exploding. This, in turn, helps to reduce the risk of the energy storage device 100 exploding and improves the safety performance of the energy storage device 100.

[0066] This application also provides an electrical device, which includes the aforementioned energy storage device 100, and the energy storage device 100 supplies power to the electrical device. The electrical device can be a new energy vehicle, a power storage station, a server, or other equipment that requires electricity.

[0067] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Where there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A type of plastic for use in energy storage devices, characterized in that, The lower plastic includes a first lower plastic and a second lower plastic. The first lower plastic and the second lower plastic are arranged sequentially along the length direction of the lower plastic. The length l1 of the first lower plastic is greater than the length l2 of the second lower plastic. The end of the second lower plastic facing the first lower plastic has a protrusion. The protrusion is located on one side of the thickness direction of the first lower plastic and supports the first lower plastic.

2. The lower plastic according to claim 1, characterized in that, The ratio of the length L1 of the lower plastic to the width W1 of the lower plastic is greater than 4, wherein the ratio of the length l1 of the first lower plastic to the length l2 of the second lower plastic is 1.5 ≤ l1 / l2 ≤ 2.

3. The lower plastic according to claim 1 or 2, characterized in that, The first lower plastic part includes a first main body and a first boss. The first main body includes a first surface and a second surface. Along the thickness direction of the first main body, the first surface and the second surface are arranged opposite to each other. The first main body is also provided with a first mounting hole. The first mounting hole passes through the first surface and the second surface and is used to install the first pole unit of the energy storage device. The first boss is fixedly connected to the first surface and protrudes relative to the first surface, and extends along the width direction of the lower plastic part. Along the length direction of the lower plastic part, the first boss is located on the side of the first mounting hole facing the second lower plastic part and is spaced apart from the first mounting hole.

4. The lower plastic according to claim 3, characterized in that, The first protrusion is provided with a first air guide channel, which extends through the first protrusion along the length of the lower plastic.

5. The lower plastic according to claim 3, characterized in that, The first lower plastic also includes a second boss, which is fixedly connected to the first surface and protrudes relative to the first surface, and extends along the width direction of the lower plastic. Along the length direction of the lower plastic, the second boss is located on the side of the first boss away from the first mounting hole and is spaced apart from the first boss.

6. The lower plastic according to claim 5, characterized in that, The surface of the second boss that is away from the first surface is flush with the surface of the first boss that is away from the first surface.

7. The lower plastic according to claim 3, characterized in that, The second lower plastic part includes a second main body and a third boss. Along the length of the lower plastic part, the second main body and the first main body are distributed sequentially. The second main body includes a third surface and a fourth surface. The third surface and the first surface face the same direction. The fourth surface is opposite to the third surface. The second main body is provided with a second mounting hole. The second mounting hole penetrates the third surface and the fourth surface. The second mounting hole is used to install the second pole unit of the energy storage device. The third boss is fixedly connected to the third surface and protrudes relative to the third surface, extending along the width direction of the lower plastic. Along the length direction of the lower plastic, the third boss is located on the side of the second mounting hole facing the first main body and is spaced apart from the second mounting hole.

8. The lower plastic according to claim 7, characterized in that, The second lower plastic part also includes a connecting part, which is connected to one end of the second main body part facing the first main body part and is disposed intersecting with the second main body part; The protruding part is fixedly connected to the end of the connecting part away from the second main body part, and is arranged intersecting with the connecting part, and supports the first main body part.

9. The lower plastic according to claim 8, characterized in that, The extension direction of the protrusion is parallel to the length direction of the first main body, and the distance between the surface of the protrusion facing the first main body and the fourth surface is equal to the thickness of the first main body.

10. The lower plastic according to claim 7, characterized in that, The third protrusion is provided with a second air guide channel, which extends through the third protrusion along the length of the lower plastic.

11. The lower plastic according to any one of claims 7 to 10, characterized in that, The surface of the third boss that is away from the third face is flush with the surface of the first boss that is away from the first face.

12. An end cap assembly, characterized in that, The device includes a cover plate, a first electrode unit, a second electrode unit, and a lower plastic as described in any one of claims 1 to 11. The first lower plastic and the second lower plastic are both located on one side of the cover plate in the thickness direction. The first lower plastic has a first mounting hole that penetrates the first lower plastic along the thickness direction. The second lower plastic has a second mounting hole that penetrates the second lower plastic along the thickness direction. The cover plate is provided with a first assembly hole and a second assembly hole. The first assembly hole and the second assembly hole penetrate the cover plate along the thickness direction and are spaced apart from each other. The first assembly hole communicates with the first mounting hole, and the second assembly hole communicates with the second mounting hole. The first pole post unit passes through the first mounting hole and the first assembly hole, and the second pole post unit passes through the second mounting hole and the second assembly hole.

13. The end cap assembly according to claim 12, characterized in that, The first lower plastic is also provided with a first vent hole, which penetrates the first lower plastic along the thickness direction and is spaced apart from the first mounting hole.

14. The end cap assembly according to claim 12, characterized in that, The second lower plastic is also provided with a second vent hole, which penetrates the second lower plastic along the thickness direction and is spaced apart from the second mounting hole.

15. The end cap assembly according to claim 12, characterized in that, The ratio of the length L2 of the cover plate to the width W2 of the cover plate is greater than 4.

16. An energy storage device, characterized in that, The device includes a housing, a battery cell, and an end cap assembly as described in any one of claims 12 to 15, wherein the housing has an opening and a receiving cavity, the opening communicates with the receiving cavity, the battery cell is received in the receiving cavity, and the end cap assembly is mounted on the housing and closes the opening.

17. The energy storage device according to claim 16, characterized in that, Along the thickness direction of the energy storage device, the surfaces of the first lower plastic away from the cover plate and the second lower plastic away from the cover plate are both disposed opposite to the battery cell, wherein the protrusion is located on the side of the first lower plastic facing the battery cell.

18. An electrical appliance, characterized in that, It includes the energy storage device as described in claim 16 or 17, wherein the energy storage device supplies power to the electrical equipment.

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