End cover assembly, energy storage device and electric equipment

Abstract

According to the end cover assembly, the energy storage device and the electric equipment provided by the invention, a reference electrode can be prevented from being corroded and damaged by an electrolyte, good detection reliability of the reference electrode is ensured, and relatively high accuracy of a detection result is ensured. The end cover assembly comprises a cover plate, a first sealing piece and a reference electrode, the cover plate is provided with an anti-explosion hole, a liquid injection hole and a through hole, the anti-explosion hole, the liquid injection hole and the through hole penetrate through the cover plate in the thickness direction of the cover plate, and the through hole and the liquid injection hole are located in the two opposite sides of the anti-explosion hole respectively and are arranged at intervals with the anti-explosion hole; the first sealing piece is installed in the through hole and is in interference fit with the through hole, the first sealing piece is provided with a first installation hole, and the first installation hole penetrates through the first sealing piece in the thickness direction of the first sealing piece; the reference electrode penetrates through the first mounting hole and is in interference fit with the first mounting hole;

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an end cap assembly, an energy storage device, and an electrical appliance. Background Technology

[0002] A rechargeable battery, also known as a secondary battery or accumulator, is a battery that can be recharged after discharge 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, so do the requirements for their energy density and reliability. In existing rechargeable batteries, a reference electrode is typically placed on the end cap assembly to measure the potential and impedance of the positive and negative electrodes relative to the reference electrode, thereby enabling the detection of the performance of the positive and negative electrodes during charging and discharging. However, during electrolyte injection, electrolyte can easily splash onto the reference electrode, damaging it and affecting the reliability of the detection results. Utility Model Content

[0003] This application provides an end cap assembly, an energy storage device, and an electrical device, which can prevent the reference electrode from being corroded and damaged by the electrolyte, ensure good detection reliability of the reference electrode, and guarantee high accuracy of the detection results.

[0004] In a first aspect, this application provides an end cap assembly for use in an energy storage device. The end cap assembly includes a cover plate, a first sealing element, and a reference electrode. The cover plate has an explosion-proof hole, a liquid injection hole, and a through hole. The explosion-proof hole, the liquid injection hole, and the through hole all penetrate the cover plate along its thickness direction. The through hole and the liquid injection hole are located on opposite sides of the explosion-proof hole and are spaced apart from it. The first sealing element is installed in the through hole and is interference-fitted with it. The first sealing element has a first mounting hole that penetrates the first sealing element along its thickness direction. The reference electrode passes through the first mounting hole and is interference-fitted with it.

[0005] The diameter of the through hole is equal to the diameter of the injection hole.

[0006] The cover plate includes a first surface and a second surface, which are arranged opposite to each other along the thickness direction of the cover plate. The explosion-proof hole, the liquid injection hole and the through hole all penetrate the first surface and the second surface. The first sealing member includes a first end face facing the same direction as the first surface. The first end face is flush with the first surface, or the first end face is located on the side of the first surface facing the second surface. The first mounting hole penetrates the first end face.

[0007] The first sealing element has a groove, the opening of which is located on the first end face. The groove surrounds the first mounting hole and communicates with it.

[0008] The first sealing element further includes a second end face, which is disposed opposite to the first end face along the thickness direction of the end cap assembly. The first mounting hole extends from the first end face to the second end face. The area of ​​the opening of the groove gradually decreases from the first end face to the second end face.

[0009] The first sealing element includes a main body and a protrusion. The main body is installed in the through hole and is interference-fitted with the through hole. The protrusion is located on the side of the second surface away from the first surface and is fixedly connected to the main body. The peripheral side of the protrusion protrudes relative to the peripheral side of the main body. Along the thickness direction of the end cap assembly, the orthographic projection of the peripheral side of the protrusion on the second surface is spaced apart from the through hole.

[0010] The end cap assembly further includes a first filler adhesive, which fills the gap between the wall of the first mounting hole and the peripheral surface of the reference electrode.

[0011] The through hole includes a first sub-hole and a second sub-hole, the second sub-hole being located on one side of the first sub-hole and communicating with the first sub-hole, the diameter of the second sub-hole being larger than the diameter of the first sub-hole; the first sealing member passes through the first sub-hole and is interference-fitted with the first sub-hole; the end cap assembly further includes a second sealing member, the second sealing member being installed in the second sub-hole and sealing the second sub-hole, the second sealing member having a second mounting hole, the second mounting hole penetrating the second sealing member along the thickness direction of the second sealing member and communicating with the first mounting hole; the reference electrode also passes through the second mounting hole.

[0012] The end cap assembly further includes a second filler adhesive, which fills the gap between the wall of the second mounting hole and the peripheral side of the reference electrode.

[0013] The reference electrode is made of enameled copper wire.

[0014] The reference electrode includes a metal portion and an insulating portion. The metal portion includes a first part and a second part. Along the length direction of the reference electrode, the first part is connected to one side of the second part and is used for electrical connection with the battery cell of the energy storage device. The second part passes through the first mounting hole. The insulating portion covers the peripheral side surface of the second part and is located between the peripheral side surface of the second part and the first mounting hole, and is spaced apart from the first part.

[0015] Secondly, this application also provides an energy storage device, including a housing, a battery cell, and an end cap assembly as described in any of the preceding claims. 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, the end cap assembly being mounted on the housing and closing the opening, and the reference electrode being electrically connected to the battery cell.

[0016] Thirdly, this application also provides an electrical device, including the energy storage device described above, wherein the energy storage device supplies power to the electrical device.

[0017] In the end cap assembly provided in this application, by having the reference electrode pass through the first mounting hole of the first seal and the first seal installed in the through hole of the cover plate, and since the through hole and the injection hole are located on opposite sides of the explosion-proof hole, when the reference electrode is installed in the first mounting hole, the reference electrode is positioned away from the injection hole. This prevents electrolyte from splashing onto the reference electrode during electrolyte injection, avoiding corrosion and damage to the reference electrode by the electrolyte. This helps ensure the high reliability of the reference electrode and the high accuracy of the detection results. Simultaneously, by interfering with the reference electrode and the first mounting hole, and interfering with the first seal and the through hole, on the one hand, the first mounting hole can prevent it from affecting the sealing performance of the first seal and preventing electrolyte leakage from the first mounting hole inside the energy storage device. On the other hand, it can also prevent electrolyte leakage from the gap between the hole wall of the through hole and the peripheral side of the first seal, thereby further reducing the risk of leakage from the energy storage device and ensuring its safety and reliability. Attached Figure Description

[0018] 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.

[0019] Figure 1 This is a schematic diagram of the energy storage device provided in the embodiments of this application;

[0020] Figure 2 yes Figure 1 The diagram shows the structure of the end cap assembly in the energy storage device.

[0021] Figure 3 yes Figure 2The exploded view of the end cap assembly is shown.

[0022] Figure 4 yes Figure 2 The diagram shows a cross-sectional view of the end cap assembly after it has been cut along point AA in the first embodiment.

[0023] Figure 5 yes Figure 3 The diagram shows the structure of the lower plastic part in the end cap assembly.

[0024] Figure 6 yes Figure 5 The diagram below shows the structure of the plastic at another angle.

[0025] Figure 7 yes Figure 3 The diagram shows the structure of the cover plate and explosion-proof valve in the end cap assembly.

[0026] Figure 8 yes Figure 7 A schematic diagram of the cross-sectional structure of the cover plate after it has been cut along point BB.

[0027] Figure 9 yes Figure 3 A schematic diagram of the structure of the first seal in the end cap assembly shown;

[0028] Figure 10 yes Figure 9 The diagram shows a cross-sectional structure of the first seal after it has been cut along point CC.

[0029] Figure 11 yes Figure 4 A partial cross-sectional structural diagram of the reference electrode in the end cap assembly shown.

[0030] Figure 12 yes Figure 2 The diagram shows a cross-sectional structure of the end cap assembly after it has been cut along point AA in the second embodiment.

[0031] Figure 13 yes Figure 12 A schematic diagram of the structure of the first seal in the end cap assembly shown;

[0032] Figure 14 yes Figure 13 The diagram shows a cross-sectional structure of the first seal after it has been cut along point DD.

[0033] Figure 15 yes Figure 2 The diagram shows a cross-sectional view of the end cap assembly after it has been cut along point AA in the third embodiment.

[0034] Figure 16 yes Figure 15A schematic cross-sectional view of the first seal in the end cap assembly shown.

[0035] Figure 17 yes Figure 2 The diagram shows a cross-sectional view of the end cap assembly after it has been cut along point AA in the fourth embodiment.

[0036] Figure 18 yes Figure 17 A cross-sectional view of the second seal in the end cap assembly shown.

[0037] The names corresponding to the labels in the figure are:

[0038] Energy storage device 100, housing 110, end cap assembly 120, lower plastic 10, cover plate 20, explosion-proof valve 30, pole unit 40, first seal 50, reference electrode 60, first mounting surface 10a, second mounting surface 10b, explosion-proof fence 101, liquid inlet 102, mating hole 103, through hole 104, limiting protrusion 11, sub-protrusion 11a, first surface 21, second surface 22, explosion-proof hole 201, liquid injection hole 202, assembly hole 203, through hole 204, first sub-hole 204a, second sub-hole 204b, first end face 51, second end face 52, first mounting hole 501, metal part 61, insulating part 62, first part 611, second part 612, groove 502, main body part 50a, protrusion 50b, second seal 70, second mounting hole 71. Detailed Implementation

[0039] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0040] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of the energy storage device 100 provided in the embodiments of this application. For ease of description, the length direction of the energy storage device 100 is defined as the X-axis direction, the width direction of the energy storage device 100 is defined as the Y-axis direction, and the height direction of the energy storage device 100 is defined as the Z-axis direction. The X-axis direction, Y-axis direction, and Z-axis direction are all perpendicular to each other.

[0041] Energy storage device 100 includes a housing 110, a battery cell (not shown), and an end cap assembly 120. The housing 110 has an opening (not shown) and a receiving cavity (not shown), the opening communicating with the receiving cavity. The battery cell is received in the receiving cavity. The receiving cavity also serves to contain electrolyte, in which the battery cell is immersed. The end cap assembly 120 is mounted on the housing 110 and closes the opening of the housing 110. Exemplarily, the energy storage device 100 is a prismatic battery. In some other embodiments, the energy storage device 100 may also be a cylindrical battery or other types of batteries.

[0042] Please see Figures 2 to 4 , Figure 2 yes Figure 1 The diagram shows the structure of the end cap assembly 120 in the energy storage device 100. Figure 3 yes Figure 2 The exploded structural diagram of the end cap assembly 120 shown is as follows: Figure 4 yes Figure 2 The diagram shows a cross-sectional view of the end cap assembly 120 after it has been cut along line AA in the first embodiment. Here, "cut along line AA" means cutting along the plane containing line AA; similar descriptions in the following text can be understood in the same way.

[0043] The end cap assembly 120 includes a lower plastic 10, a cover plate 20, an explosion-proof valve 30, two electrode units 40, a first sealing element 50, and a reference electrode 60. The lower plastic 10 is mounted on one side of the cover plate 20 in the thickness direction. The explosion-proof valve 30 and the two electrode units 40 are both mounted on the cover plate 20. Along the length of the energy storage device 100, the two electrode units 40 are located on opposite sides of the explosion-proof valve 30. The first sealing element 50 is mounted on the lower plastic 10 and the cover plate 20. The reference electrode 60 is mounted on the first sealing element 50 and electrically connected to the battery cell of the energy storage device 100.

[0044] Please refer to the following: Figure 4 , Figure 5 and Figure 6 , Figure 5 yes Figure 3 The diagram shows the structure of the lower plastic 10 in the end cap assembly 120. Figure 6 yes Figure 5 The diagram below shows the structure of plastic 10 at another angle.

[0045] The lower plastic 10 includes a first mounting surface 10a and a second mounting surface 10b, which are arranged opposite to each other along the thickness direction of the lower plastic 10. The first mounting surface 10a is the surface of the lower plastic 10 facing the housing 110, and the second mounting surface 10b is the surface of the lower plastic 10 away from the housing 110. The lower plastic 10 also includes an explosion-proof barrier 101, which penetrates both the first mounting surface 10a and the second mounting surface 10b of the lower plastic 10. Specifically, the explosion-proof barrier 101 is located in the middle of the lower plastic 10.

[0046] In this embodiment, the lower plastic 10 is further provided with a liquid inlet hole 102, two mating holes 103, and a through hole 104. The liquid inlet hole 102, the two mating holes 103, and the through hole 104 all penetrate the first mounting surface 10a and the second mounting surface 10b of the lower plastic 10 and are spaced apart from each other. Exemplarily, the liquid inlet hole 102, the two mating holes 103, and the through hole 104 are all circular holes. In other embodiments, the liquid inlet hole 102, the two mating holes 103, and the through hole 104 may also be square holes or irregularly shaped holes; the embodiments of this application do not impose any limitations on this.

[0047] Specifically, along the length of the energy storage device 100 (X-axis direction in the diagram), the liquid inlet 102 is located in the middle of the lower plastic 10 and on one side of the explosion-proof fence 101, and is spaced apart from the explosion-proof fence 101. Along the length of the energy storage device 100 (X-axis direction in the diagram), two mating holes 103 are both located at the edge of the lower plastic 10, and are spaced apart from both the liquid inlet 102 and the explosion-proof fence 101. Specifically, one mating hole 103 is located on the side of the liquid inlet 102 away from the explosion-proof fence 101, and the other mating hole 103 is located on the side of the explosion-proof fence 101 away from the liquid inlet 102.

[0048] In addition, the lower plastic 10 is also provided with a limiting protrusion 11. The limiting protrusion 11 is provided on the first mounting surface 10a, protrudes relative to the first mounting surface 10a, and surrounds a through hole 104. In this embodiment, the limiting protrusion 11 includes a plurality of sub-protrusions 11a. The plurality of sub-protrusions 11a are spaced apart around a through hole 104.

[0049] Please refer to the following: Figure 4 , Figure 7 and Figure 8 , Figure 7 yes Figure 3 The diagram shows the structure of the cover plate 20 and the explosion-proof valve 30 in the end cap assembly 120. Figure 8 yes Figure 7 The diagram shows a cross-sectional view of the cover plate 20 after it is cut open along BB.

[0050] The cover plate 20 is mounted on the second mounting surface 10b of the lower plastic 10. In this embodiment, the cover plate 20 includes a first surface 21 and a second surface 22, which are arranged opposite to each other along the thickness direction of the cover plate 20 (Z-axis direction in the figure). Specifically, the first surface 21 is the side of the cover plate 20 facing away from the lower plastic 10, and the second surface 22 is the side of the cover plate 20 facing the lower plastic 10.

[0051] The cover plate 20 also includes an explosion-proof hole 201, an injection hole 202, two assembly holes 203, and a through hole 204. The explosion-proof hole 201, injection hole 202, two assembly holes 203, and through hole 204 all penetrate the cover plate 20 along its thickness direction and are spaced apart from each other. Specifically, the explosion-proof hole 201, injection hole 202, two assembly holes 203, and through hole 204 all penetrate the first surface 21 and the second surface 22 of the cover plate 20. For example, the explosion-proof hole 201 is an elliptical hole, and the injection hole 202, two assembly holes 203, and through hole 204 are all circular holes. In other embodiments, the explosion-proof hole 201 may also be a circular hole, a square hole, or an irregularly shaped hole, and the injection hole 202, two assembly holes 203, and through hole 204 may also be square holes or irregularly shaped holes, etc. The embodiments of this application do not impose any limitations on these aspects.

[0052] In this embodiment, the explosion-proof hole 201 is located in the middle of the cover plate 20. The explosion-proof hole 201 can connect to the interior of the energy storage device 100 through the explosion-proof fence 101. Along the length direction of the cover plate 20 (X-axis direction in the figure), the injection hole 202 and the through hole 204 are located on opposite sides of the explosion-proof hole 201, and are spaced apart from the explosion-proof hole 201. Among them, the injection hole 202 is connected to the liquid inlet hole 102 of the lower plastic 10. Electrolyte can be injected into the housing 110 (e.g., through the injection hole 202 of the cover plate 20 and the liquid inlet hole 102 of the lower plastic 10) in sequence. Figure 1 The cavity shown is used to fill the electrolyte of the energy storage device 100.

[0053] The through hole 204 communicates with the through hole 104 of the lower plastic 10 to facilitate the subsequent installation of the first sealing element 50. In this embodiment, the structure of the through hole 204 is the same as that of the injection hole 202, and the diameter of the through hole 204 is equal to that of the injection hole 202. The through hole 204 includes a first sub-hole 204a and a second sub-hole 204b. The second sub-hole 204b is located on one side of the first sub-hole 204a and is connected to it. The diameter of the second sub-hole 204b is larger than the diameter of the first sub-hole 204a.

[0054] Furthermore, the distance d between the center of the opening of the through hole 204 and the center of the opening of the injection hole 202 is 2.6cm ≤ d ≤ 4.6cm. With this setting, on the one hand, it can ensure that the through hole 204 is as far away from the injection hole 202 as possible, avoiding damage to the reference electrode 60 installed in the through hole 204 by the electrolyte during the subsequent injection process. On the other hand, it can also prevent the through hole 204 from interfering with the electrode post unit 40 subsequently installed on the cover plate 20, ensuring that the end cap assembly 120 can be successfully assembled.

[0055] Along the length of the energy storage device 100 (X-axis direction in the diagram), two mounting holes 203 are located on the edge of the cover plate 20, and are respectively located on opposite sides of the explosion-proof hole 201. Specifically, one mounting hole 203 is located on the side of the injection hole 202 away from the explosion-proof hole 201, and the other mounting hole 203 is located on the side of the through hole 204 away from the explosion-proof hole 201. Each mounting hole 203 communicates with a mating hole 103 of the lower plastic 10 to facilitate the installation of an electrode post unit 40.

[0056] Please continue reading. Figure 4 and Figure 7 The explosion-proof valve 30 is installed in the explosion-proof hole 201 and fixedly connected to the hole wall of the explosion-proof hole 201. For example, the explosion-proof valve 30 can be fixedly connected to the hole wall of the explosion-proof hole 201 by welding. It is understood that since the explosion-proof hole 201 connects the interior and exterior of the energy storage device 100, when the internal gas pressure of the energy storage device 100 is too high, the explosion-proof valve 30 will rupture under the pressure. The gas inside the energy storage device 100 can then be discharged to the exterior of the energy storage device 100 in a timely manner through the explosion-proof fence 101 of the lower plastic 10 and the explosion-proof hole 201, preventing the energy storage device 100 from exploding and improving the reliability of the energy storage device 100.

[0057] Please refer to the following: Figure 4 , Figure 9 and Figure 10 , Figure 9 yes Figure 3 The diagram shows the structure of the first seal 50 in the end cap assembly 120. Figure 10 yes Figure 9 The diagram shows a cross-sectional view of the first seal 50 after it has been cut along CC.

[0058] The first sealing element 50 passes through the through hole 204 of the cover plate 20 and the through hole 104 of the lower plastic 10, and is interference-fitted with the through hole 204. Specifically, the first sealing element 50 is interference-fitted with the first sub-hole 204a of the through hole 204. For example, the first sealing element 50 is a sealing nail. It is understood that the first sealing element 50 is elastic; by interfering with the through hole 204, the through hole 204 can be sealed, preventing leakage of electrolyte from the energy storage device 100 through the assembly gap between the first sealing element 50 and the hole wall of the through hole 204. Simultaneously, the limiting protrusion 11 of the lower plastic 10 surrounds the first sealing element 50. In this configuration, the limiting protrusion 11 can limit the first sealing element 50, preventing it from tilting, thereby helping to ensure the interference fit between the first sealing element 50 and the through hole 204.

[0059] In this embodiment, the shape of the first sealing member 50 is adapted to the shape of the through hole 204. For example, the first sealing member 50 is generally cylindrical. In some other embodiments, the first sealing member 50 may also be a rectangular column or other irregularly shaped structure, as long as it is adapted to the shape of the through hole 204.

[0060] Understandably, since the diameter of the through hole 204 is the same as that of the injection hole 202, and the structure of the through hole 204 is the same as that of the injection hole 202, the first sealing element 50 can also be adapted to the injection hole 202. In other words, the sealing element for sealing the injection hole 202 can be directly used to seal the through hole 204. Under this configuration, only a small-scale structural optimization is needed based on the existing structure of the sealing element for sealing the injection hole 202 to prepare a first sealing element 50 with high adaptability and simple structure, without adding extra manufacturing steps in the production process. This helps to save labor costs, save production materials, and improve production efficiency.

[0061] Specifically, the first sealing element 50 includes a first end face 51 and a second end face 52. Along the length of the first sealing element 50, the first end face 51 and the second end face 52 are arranged opposite to each other. The orientation of the first end face 51 is the same as the orientation of the first surface 21 of the cover plate 20, and the orientation of the second end face 52 is the same as the orientation of the second surface 22. In this embodiment, the first end face 51 is flush with the first surface 21, or the first end face 51 is located on the side of the first surface 21 facing the second surface 22. The first sealing element 50 is provided with a first mounting hole 501, which penetrates the first sealing element 50 along its length. Specifically, the first mounting hole 501 penetrates both the first end face 51 and the second end face 52.

[0062] It is understandable that by making the first end face 51 flush with the first surface 21, or by placing the first end face 51 on the side of the first surface 21 facing the second surface 22, it can be ensured that the first end face 51 of the first seal 50 will not be higher than the first surface 21, thus preventing the first seal 50 from protruding relative to the first surface 21 of the cover plate 20. This can prevent the first seal 50 from affecting the subsequent welding of the aluminum bar connecting piece of the energy storage device 100, and ensure the smooth completion of the test.

[0063] Please refer to the following: Figure 4 and Figure 11 , Figure 11 yes Figure 4 A partial cross-sectional view of the reference electrode 60 in the end cap assembly 120 shown.

[0064] The reference electrode 60 passes through the first mounting hole 501 of the first sealing member 50 and is interference-fitted with the first mounting hole 501. In this embodiment, by having the reference electrode 60 pass through the first mounting hole 501 of the first sealing member 50 and the first sealing member 50 installed in the through hole 204 of the cover plate 20, since the through hole 204 is located on the side of the explosion-proof hole 201 away from the liquid injection hole 202, when the reference electrode 60 is installed in the first mounting hole 501 of the first sealing member 50, the reference electrode 60 is positioned away from the liquid injection hole 202. This prevents electrolyte from splashing onto the reference electrode 60 when the energy storage device 100 is injecting liquid, avoiding electrolyte corrosion damage to the back of the reference electrode 60, and thus helping to ensure good detection reliability of the reference electrode 60 and high accuracy of the detection results. Meanwhile, by making the reference electrode 60 interference fit with the first mounting hole 501, the first mounting hole 501 can be prevented from affecting the sealing performance of the first seal 50, and the electrolyte inside the energy storage device 100 can be prevented from leaking from the first mounting hole 501.

[0065] In this embodiment, the reference electrode 60 is made of enameled copper wire. Specifically, the reference electrode 60 includes a metal portion 61 and an insulating portion 62. The metal portion 61 includes a first part 611 and a second part 612. Along the length of the reference electrode 60, the first part 611 is connected to one side of the second part 612 and is used for electrical connection with the battery cell of the energy storage device 100. The second part 612 passes through the first mounting hole 501. The insulating portion 62 covers the peripheral side surface of the second part 612 and is located between the second part 612 and the hole wall of the first mounting hole 501, and is spaced apart from the first part 611.

[0066] It should be understood that when using enameled copper wire to fabricate the reference electrode 60, the enameled copper wire needs to be acid-washed first to remove part of the enameled layer on its surface. At this time, the remaining enameled layer on the surface of the enameled copper wire forms the insulating portion 62 of the reference electrode 60. After the reference electrode 60 is assembled with the first sealing element 50, since the insulating portion 62 covers the second part of the reference electrode 60, the insulating portion 62 can directly achieve insulation. The outer periphery of the second part 612 of the metal portion 61 in the reference electrode 60 does not need to be manually wrapped with insulating blue glue. This solves the problem of poor product consistency in the energy storage device 100 caused by significant differences in individual production techniques, ensuring good product consistency of the energy storage device 100, and also helps save manpower and improve the production efficiency of the energy storage device 100. Simultaneously, the seamless existence between the insulating portion 62 and the second part 612 helps reduce the risk of leakage in the energy storage device 100, improving the safety and reliability of the energy storage device 100.

[0067] During the actual production and handling of the energy storage device 100, or when the energy storage device 100 is in an inverted state, a gap may occur between the hole wall of the first mounting hole 501 of the first seal 50 and the reference electrode 60. In this case, the end cap assembly 120 also includes a first filler adhesive (not shown). The first filler adhesive fills the gap between the hole wall of the first mounting hole 501 and the peripheral surface of the reference electrode 60 to further achieve an effective seal and ensure a good sealing effect of the first seal 50. For example, the first filler adhesive can be a two-component mixed hardening adhesive (abbreviated as AB adhesive). In some other embodiments, the first filler adhesive can also be other substances capable of sealing the first mounting hole 501 of the first seal 50. In still other embodiments, a dispensing process can also be used to seal the gap between the hole wall of the first mounting hole 501 of the first seal 50 and the peripheral surface of the reference electrode 60.

[0068] When the reference electrode 60 is assembled with the battery cell, the first portion 611 of the metal part 61 of the reference electrode 60 is sandwiched between the positive and negative electrode plates of the battery cell and is electrically connected to the positive and negative electrode plates, thereby achieving electrical connection between the reference electrode 60 and the battery cell. When the measuring device tests the performance of the positive and negative electrodes of the energy storage device 100 through the reference electrode 60, the second portion 612 of the metal part 61 of the reference electrode 60 is electrically connected to the testing device, thereby achieving electrical conduction between the measuring device and the battery cell, thus enabling the measuring device to test the performance of the positive and negative electrodes of the energy storage device 100.

[0069] It should be noted that the peripheral side of the second portion 612 of the metal part 61 is covered by the insulating part 62, while the end face of the second portion 612 away from the first portion 611 is not covered by the insulating part 62. Therefore, the second portion 612 can conduct electricity with the measuring device. In the actual measurement process, if the end face of the second portion 612 away from the first portion is covered by the insulating part 62, it is necessary to first remove the insulating part 62 covering the end face of the second portion 612 away from the first portion, and then electrically connect the second portion 612 to the measuring device. This enables the measuring device and the battery cell to conduct electricity, thereby allowing the measuring device to test the performance of the positive and negative electrodes of the energy storage device 100.

[0070] Please refer to the following: Figures 12 to 14 , Figure 12 yes Figure 2 The diagram shows a cross-sectional view of the end cap assembly 120 after it has been cut along point AA in the second embodiment. Figure 13 yes Figure 12 The diagram shows the structure of the first seal 50 in the end cap assembly 120. Figure 14 yes Figure 13 The diagram shows a cross-sectional view of the first seal 50 after it has been cut along DD.

[0071] The end cap assembly 120 shown in this embodiment differs from the end cap assembly 120 shown in the first embodiment in that the first sealing member 50 also has a groove 502. The opening of the groove 502 is located on the first end face 51, and the groove 502 is recessed from the first end face 51 toward the second end face 52. The groove 502 surrounds the first mounting hole 501 and communicates with the first mounting hole 501. With this arrangement, on the one hand, it is convenient for the reference electrode 60 to pass through the first mounting hole 501 of the first sealing member 50, which helps to improve production efficiency. In addition, the area of ​​the opening of the groove 502 gradually decreases from the first end face 51 toward the second end face 52. When there is an assembly gap between the reference electrode 60 and the hole wall of the first mounting hole 501, this arrangement facilitates the filling of the first filler adhesive, thereby achieving an effective seal.

[0072] Please refer to the following: Figure 15 and Figure 16 , Figure 15 yes Figure 2 The diagram shows a cross-sectional view of the end cap assembly 120 after it has been cut along point AA in the third embodiment. Figure 16 yes Figure 15 A cross-sectional view of the first seal 50 in the end cap assembly 120 shown.

[0073] The end cap assembly 120 shown in this embodiment differs from the end cap assembly 120 shown in the first embodiment in that the first sealing member 50 includes a main body portion 50a and a protrusion portion 50b. The main body portion 50a passes through the through hole 204 and the through hole 104, and is press-fitted with the through hole 204. The main body portion 50a is press-fitted with the first sub-hole 204a.

[0074] The protrusion 50b is located on the side of the second surface 22 opposite to the first surface 21 and is fixedly connected to the main body 50a. The peripheral side surface of the protrusion 50b protrudes relative to the peripheral side surface of the main body 50a. Along the thickness direction of the end cap assembly 120, the peripheral side surface of the protrusion 50b is spaced apart from the through hole 204 in the orthographic projection of the second surface 22. In this embodiment, the protrusion 50b is arranged around the main body 50a. The peripheral side surface of the protrusion 50b is spaced apart from the through hole 204 in the orthographic projection of the second surface 22 along the thickness direction of the end cap assembly 120.

[0075] In this embodiment, when the reference electrode 60 is installed from inside the energy storage device 100 into the first mounting hole 501 of the first seal 50, the first seal 50 is at risk of falling off from the through hole 204 of the cover plate 20 to the outside of the energy storage device 100 under the influence of the reference electrode 60. By providing a protrusion 50b on the first seal 50 and positioning the protrusion 50b on the side of the second surface 22 opposite to the first surface 21, the protrusion 50b can be interlocked with the cover plate 20, preventing the first seal 50 from falling off from the through hole 204 of the cover plate 20 during installation. This provides an anti-push function and ensures that the first seal 50 is always in an interference fit with the through hole 204, achieving effective sealing.

[0076] Please refer to the following: Figure 17 and Figure 18 , Figure 17 yes Figure 2 The diagram shows a cross-sectional view of the end cap assembly 120 after it has been cut along point AA in the fourth embodiment. Figure 18 yes Figure 17 A cross-sectional view of the second seal 70 in the end cap assembly 120 shown.

[0077] The end cap assembly 120 shown in this embodiment differs from the end cap assembly 120 shown in the first embodiment in that the end cap assembly 120 further includes a second sealing member 70. Specifically, the second sealing member 70 is installed in the second sub-hole 204b of the through hole 204 and seals the second sub-hole 204b. For example, the second sealing member 70 can be a sealing aluminum nail. The second sealing member 70 can be fixedly connected to the cover plate 20 by laser welding. In this embodiment, the second sealing member 70 is provided with a second mounting hole 71. The second mounting hole 71 penetrates the second sealing member 70 along its thickness direction and communicates with the first mounting hole 501.

[0078] In this embodiment, the reference electrode 60 also passes through the second mounting hole 71. Furthermore, the end cap assembly 120 includes a second filler adhesive. The second filler adhesive fills the gap between the wall of the second mounting hole 71 and the peripheral surface of the reference electrode 60 to achieve an effective seal.

[0079] Understandably, by providing the second sealing element 70, multiple seals can be achieved, further improving the sealing effect at the mounting position of the reference electrode 60 in the end cap assembly 120. This prevents the electrolyte inside the energy storage device 100 from leaking through the gaps at the mounting position of the reference electrode 60, thereby helping to further reduce the risk of leakage in the energy storage device 100 and improve its safety and reliability. Furthermore, by providing a second filler adhesive, the sealing effect of the second sealing element 70 can be further improved, further reducing the risk of leakage in the energy storage device 100 and enhancing its safety and reliability.

[0080] 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.

[0081] 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. An end cap assembly for use in an energy storage device, characterized by, The end cover assembly comprises a cover plate, a first sealing member and a reference electrode, the cover plate is provided with an explosion-proof hole, a liquid injection hole and a through hole, the explosion-proof hole, the liquid injection hole and the through hole all penetrate the cover plate along the thickness direction of the cover plate, the through hole and the liquid injection hole are respectively located on the opposite sides of the explosion-proof hole and are arranged in a spaced manner with the explosion-proof hole; The first sealing member is installed in the through hole and is in interference fit with the through hole, the first sealing member is provided with a first mounting hole penetrating the first sealing member along the thickness direction of the first sealing member; The reference electrode is arranged in the first mounting hole and is in interference fit with the first mounting hole.

2. The end cap assembly of claim 1, wherein, The diameter of the through hole is equal to the diameter of the liquid injection hole.

3. The end cap assembly of claim 2, wherein, The cover plate comprises a first surface and a second surface, the first surface and the second surface are arranged in a back-to-back manner along the thickness direction of the cover plate, and the explosion-proof hole, the liquid injection hole and the through hole all penetrate the first surface and the second surface; The first sealing member comprises a first end face which is in the same direction as the first surface, the first end face is flush with the first surface, or the first end face is located on the side of the first surface facing the second surface; and the first mounting hole penetrates the first end face.

4. The end cap assembly of claim 3, wherein, The first sealing member is provided with a groove, the opening of the groove is located on the first end face, the groove is arranged around the first mounting hole and is in communication with the first mounting hole.

5. The end cap assembly of claim 4, wherein, The first sealing member further comprises a second end face, the second end face is arranged in a back-to-back manner with the first end face along the thickness direction of the end cover assembly, wherein the first mounting hole penetrates from the first end face to the second end face; The area of the opening of the groove gradually decreases in the direction from the first end face to the second end face.

6. The end cap assembly of claim 3, wherein, The first sealing member comprises a main body portion and a protruding portion, the main body portion is installed in the through hole and is in interference fit with the through hole, the protruding portion is located on the side of the second surface away from the first surface and is fixedly connected to the main body portion, the circumferential surface of the protruding portion is protruded relative to the circumferential surface of the main body portion, and the circumferential surface of the protruding portion is arranged in a spaced manner with the through hole in the orthographic projection of the second surface along the thickness direction of the end cover assembly.

7. The end cap assembly of claim 1, wherein, The end cover assembly further comprises a first filling glue, the first filling glue fills the gap between the hole wall surface of the first mounting hole and the circumferential surface of the reference electrode.

8. The end cap assembly of claim 1, wherein, The through hole comprises a first sub-hole and a second sub-hole, the second sub-hole is located on one side of the first sub-hole and is in communication with the first sub-hole, and the diameter of the second sub-hole is greater than the diameter of the first sub-hole; The first sealing member is arranged in the first sub-hole and is in interference fit with the first sub-hole; The end cover assembly further comprises a second sealing member, the second sealing member is installed in the second sub-hole and seals the second sub-hole, the second sealing member is provided with a second mounting hole penetrating the second sealing member along the thickness direction of the second sealing member and in communication with the first mounting hole; The reference electrode is further arranged in the second mounting hole.

9. The end cap assembly of claim 8, wherein, The end cover assembly further comprises a second filling adhesive, which fills the gap between the hole wall surface of the second mounting hole and the circumferential surface of the reference electrode.

10. The end cap assembly of claim 1, wherein, The reference electrode is made of an enameled copper wire.

11. The end cap assembly of any one of claims 1 to 10, wherein, The reference electrode comprises a metal part and an insulating part, the metal part comprises a first part and a second part, along the length direction of the reference electrode, the first part is connected to one side of the second part and used for electrically connecting with the cell of the energy storage device, and the second part is arranged through the first mounting hole. The insulating part covers the circumferential surface of the second part and is arranged between the circumferential surface of the second part and the first mounting hole and spaced apart from the first part.

12. An energy storage device, characterized by The energy storage device comprises a shell, a cell and the end cover assembly as claimed in any one of claims 1 to 11, the shell has an opening and a receiving cavity, the opening communicates with the receiving cavity, the cell is received in the receiving cavity, the end cover assembly is mounted on the shell and closes the opening, and the reference electrode is electrically connected to the cell.

13. An electrical device, characterized by The energy storage device as claimed in claim 12 is used for supplying power to the electric device.

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