End cap assembly, energy storage device, and electric appliance

Abstract

The application discloses an end cover assembly, an energy storage device and an electric equipment. The end cover assembly comprises a lower plastic, a pin and a thermal insulation piece. The lower plastic comprises a body and an assembly groove. The body comprises a top surface and a bottom surface arranged oppositely along the thickness direction of the body. The assembly groove comprises a groove bottom surface. The groove bottom surface of the assembly groove and the bottom surface are in the same direction. The pin comprises a connecting portion, an adapter portion and a bending portion connecting the connecting portion and the adapter portion. The connecting portion and the adapter portion form an included angle. The connecting portion is accommodated in the assembly groove, and the adapter portion extends away from the lower plastic. The connecting portion comprises an inner surface, the inner surface faces away from the groove bottom surface. The adapter portion comprises an inner side surface. The bending portion comprises an inner arc surface, the inner arc surface connects the inner surface and the inner side surface. The thermal insulation piece is stacked on the pin, and the thermal insulation piece completely covers the inner surface and the inner side surface. The thermal insulation piece comprises a thickened area, and the thickened area completely covers the inner arc surface.

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] With the continuous advancement of energy storage technology, the requirements for the internal structure of energy storage devices are becoming increasingly stringent. Existing energy storage devices typically employ either laminated or wound cell designs. When using a laminated cell design, the tabs are led out from the cell, bent, and then soldered to the leads. However, soldering the tabs to the leads easily generates high temperatures, which are transferred through the leads to the cell, causing a series of defects and reducing the yield rate of the energy storage device. Summary of the Invention

[0003] This application provides an end cap assembly, an energy storage device, and an electrical device that can prevent the high temperature generated during the soldering of the tabs and pins from affecting the battery cell and improve the yield of the energy storage device.

[0004] This application provides an end cap assembly, the end cap assembly comprising:

[0005] The lower plastic includes a body, which includes a top surface and a bottom surface. The top surface and the bottom surface are arranged opposite to each other along the thickness direction of the body. The lower plastic also includes an assembly groove, which includes a bottom surface. The bottom surface and the bottom surface face the same direction.

[0006] The pin includes a connecting portion, an adapter portion, and a bent portion connecting the connecting portion and the adapter portion. The extending direction of the connecting portion and the extending direction of the adapter portion form an angle. The connecting portion is accommodated in the assembly groove, and the adapter portion extends in a direction away from the lower plastic.

[0007] The connecting portion includes an outer surface and an inner surface, the inner surface and the outer surface being disposed opposite to each other along the thickness direction of the connecting portion. The outer surface is connected to the bottom surface of the groove, and the inner surface faces away from the bottom surface of the groove. The transition portion includes an inner side surface, and the bending portion includes an inner arc surface, the inner arc surface connecting the inner surface and the inner side surface.

[0008] A heat insulation element is stacked on the pin and completely covers the inner surface and the inner side surface. The heat insulation element includes a thickened area that completely covers the inner arc surface.

[0009] In related technologies, when the battery cell body adopts a laminated design, the tabs are led out from the battery cell body, bent, and then soldered to the pins. However, the soldering of the tabs and pins can easily generate high temperatures, which are transferred to the battery cell through the pins, causing a series of defects in the battery cell body, such as thermal shrinkage, melting, and damage to the separator between the positive and negative electrodes, thus reducing the yield of the energy storage device.

[0010] In this application, a heat insulation component (i.e., high-temperature adhesive) is provided in plastic under the pins and the portion connected to the pins. The heat insulation component covers the inner surface of the pin connection portion, the inner side of the transition portion, and the inner arc surface of the bend portion. This physically blocks heat conduction from the pins towards the cell body, reducing the high temperatures generated during the welding of the tabs and pins, and minimizing the impact of the high temperatures transferred to the pins on the cell body. This avoids defects such as thermal shrinkage, melting, and damage to the separator between the positive and negative electrodes, prevents direct contact between the positive and negative electrodes, and avoids short circuits in the cell. Simultaneously, it ensures temperature consistency between the first and second pins, which helps improve the overall service life of the energy storage device and increases its yield rate.

[0011] Furthermore, the thermal insulation component features a thickened area on the inner arc surface of the bend. This thickened area can be understood as an region where the thickness of the thermal insulation component is increased, and it can be an area formed by the overlapping of multiple thermal insulation components. The increased thickness of this thickened area covering the bend better blocks heat conduction from the pins to the cell body, thus improving heat insulation of the pins during overcurrent. Simultaneously, as the area of ​​the thickened area increases, the mutual tensile force between adjacent thermal insulation components increases, and the adhesion of the thermal insulation component to the pins becomes stronger, which helps improve the yield rate of the energy storage device.

[0012] In one embodiment, the thickened area covers a portion of the inner side surface and / or a portion of the inner surface connecting the two sides of the inner arc surface.

[0013] It is understandable that, in addition to setting a thickened area on the inner arc surface of the bend, the heat insulation component can also set a thickened area on part of the inner surface of the connecting part and part of the inner side of the transition part to increase the contact area between the pin and the heat insulation component, effectively blocking the heat conduction between the pin and the battery cell body.

[0014] In one embodiment, the ratio of the area of ​​the thickened region to the area of ​​the inner arc surface is greater than or equal to 1.2 and less than or equal to 5.

[0015] It is understandable that the area of ​​the thickened area is larger than the area of ​​the inner arc surface, which further effectively isolates the heat conduction between the pins and the battery cell body.

[0016] In one embodiment, the heat insulation member includes an end heat insulation member and a side heat insulation member, the side heat insulation member covering the inner side surface and the inner arc surface, and the end heat insulation member covering the inner arc surface and the inner surface;

[0017] The end heat insulation component and the side heat insulation component partially overlap, and the overlapping portion of the end heat insulation component and the side heat insulation component is the thickened area.

[0018] It is understood that the side heat insulation covers the inner arc surface and the inner side surface, and the end heat insulation covers the inner surface and the inner arc surface. The overlapping portion of the side heat insulation and the end heat insulation covers the inner arc surface, that is, the side heat insulation and the end heat insulation are stacked to form the thickened area. The mutual tensile force between the side heat insulation and the end heat insulation increases, and the adhesion of the heat insulation to the pins increases, which is more conducive to blocking the heat conduction from the junction to the cell body and improving the yield of the energy storage device.

[0019] In one embodiment, the bottom surface is provided with a boss, the boss including a boss surface facing away from the bottom surface; the assembly groove is recessed in the boss surface and located at the end of the lower plastic in the length direction;

[0020] The end heat insulation completely covers the boss surface, or the end heat insulation completely covers the boss surface and the bottom surface of the lower plastic on the side of the boss facing away from the mounting groove.

[0021] It is understood that the end heat insulation component completely covers the boss surface and the bottom surface of the lower plastic on the side of the boss facing away from the mounting groove in the width direction. The larger the contact area between the end heat insulation component and the lower plastic, the more beneficial it is to separate the lower plastic from the cell body, so as to maximize the blocking of heat conduction from the pins and the lower plastic near the pins to the cell body, and avoid the impact of high temperature on the cell.

[0022] In one embodiment, the bottom surface is provided with a boss, the boss including a boss surface facing away from the bottom surface; the assembly groove is recessed in the boss surface and located at the end of the lower plastic in the length direction;

[0023] Along the width direction of the lower plastic, the width of the end heat insulation member is greater than the width of the pin, and the width of the end heat insulation member exceeding the width of the pin is called the excess width. The ratio of the width of the thickened area to the excess width is greater than or equal to 1.1 and less than or equal to 3.

[0024] It is understood that the width of the end heat insulation component is greater than the width of the pin connection portion to completely separate the lower plastic from the cell body, blocking heat conduction between the pin and the lower plastic near the pin and the cell body, thus avoiding the impact of high temperature on the cell. In some embodiments, the width of the end heat insulation component can also be greater than the width of the boss. The end heat insulation component not only covers the inner surface and the boss surface, but also covers the bottom surface of the lower plastic on the side of the boss facing away from the mounting groove. The contact area between the end heat insulation component and the lower plastic is further increased, which is more conducive to separating the lower plastic from the cell body, so as to maximize the blocking of heat conduction from the pin and the lower plastic near the pin towards the cell body, and further avoid the impact of high temperature on the cell.

[0025] In addition, since the thermal conductivity from the pin to the lower plastic is poor and the thermal conductivity from the pin to the cell body is good, the width of the thickened area formed by the overlap of the end insulation and the side insulation needs to be greater than the excess width. The ratio of the width of the thickened area to the excess width is greater than or equal to 1.1 and less than or equal to 3. This not only fully avoids thermal conduction between the bent part and the cell body, but also avoids using too much material for the insulation, which would be wasteful.

[0026] In one embodiment, the side insulation further covers a portion of the inner surface, the end insulation further covers a portion of the inner side surface, and the overlapping portion of the end insulation and the side insulation covers a portion of the inner side surface and a portion of the inner surface.

[0027] It is understandable that the side insulation covers part of the inner surface, inner arc surface, and inner side surface, while the end insulation covers the inner surface, inner arc surface, and part of the inner side surface. The overlapping portion of the side and end insulation covers part of the inner surface, inner arc surface, and part of the inner side surface, meaning the area of ​​the thickened region is further increased. The mutual tensile force between the side and end insulation increases, and the adhesion of the insulation to the pins increases, which is more conducive to blocking heat conduction from the junction to the cell body and improving the yield of the energy storage device.

[0028] In one embodiment, the end heat insulation member and the side heat insulation member are integrally formed, or the end heat insulation member and the side heat insulation member are separately formed.

[0029] It is understood that thermal insulation components include end thermal insulation components and side thermal insulation components. End thermal insulation components and side thermal insulation components can be manufactured separately or integrally to meet different needs in actual production applications.

[0030] In one embodiment, the bottom surface is further provided with a protrusion, the protrusion and the boss are arranged adjacent to each other along the length direction of the lower plastic, the protrusion protrudes from the bottom surface of the boss, the protrusion includes an inner side surface, the inner side surface of the protrusion faces the boss and is connected to the boss surface, and the edge of the end heat insulation member abuts against the inner side surface of the protrusion.

[0031] It is understandable that when the protrusion protrudes beyond the bottom surface and the inner side of the protrusion connects with the boss surface, the end heat insulation component not only covers the inner surface of the connecting part and the inner arc surface of the bent part, but also covers and connects the boss surface around the connecting part. Furthermore, the edge of the end heat insulation component away from the side heat insulation component adheres to the inner side of the protrusion. This not only increases the contact area between the end heat insulation component and the lower plastic, reduces the instability of the end heat insulation component when impacted by the electrolyte, and improves the adhesion effect of the end heat insulation component on the lower plastic, but also the inner side of the protrusion plays a limiting role in the adhesion of the end heat insulation component, thereby increasing the adhesion rate of the end heat insulation component.

[0032] In one embodiment, the bottom surface is further provided with a protrusion, the protrusion and the boss are arranged adjacent to each other along the length direction of the lower plastic, the protrusion includes a protruding surface, the protruding surface faces away from the bottom surface, the end heat insulation member covers the boss surface and the protruding surface, or the end heat insulation member covers the outer side of the protrusion facing away from the boss; and / or, the end heat insulation member covers a portion of the bottom surface of the lower plastic located on the side of the protrusion facing away from the boss.

[0033] It is understandable that the end heat insulation component not only covers the inner surface of the connecting part and the inner arc surface of the bent part, but also covers and connects the raised surface and the boss surface of the boss, further increasing the contact area between the end heat insulation component and the lower plastic and improving the adhesion effect of the end heat insulation component on the lower plastic.

[0034] In one embodiment, the pin includes a first pin and a second pin, which are located at opposite ends of the lower plastic along its length. The first pin is a positive pin, and the second pin is a negative pin.

[0035] The end heat insulation component includes a first end heat insulation component and a second end heat insulation component, and the side heat insulation component includes a first side heat insulation component and a second side heat insulation component. The first end heat insulation component and the first side heat insulation component cover the first pin, and the second end heat insulation component and the second side heat insulation component cover the second pin.

[0036] It is understood that the first pin and the second pin are connected to opposite ends along the length of the battery cell, and are electrically connected to the first tab and the second tab, respectively. Because the positive and negative pins are made of different materials, the dimensions of the heat insulation covering the first and second pins differ when the positive and negative pins need to meet overcurrent requirements. This will be explained using the example of the first pin being the positive pin and the second pin being the negative pin.

[0037] In one embodiment, the end cap assembly further includes an electrode post and an end cap. The end cap and the lower plastic are stacked along the thickness direction of the end cap assembly. The end cap includes an electrode post through-hole that penetrates both surfaces of the end cap in the thickness direction. The connecting portion includes a through-hole that penetrates the inner surface and the outer surface. The lower plastic also includes a through-hole that penetrates the bottom surface and the top surface of the groove. The electrode post through-hole, the through-hole, and the through-hole are coaxially arranged. The electrode post passes through the electrode post through-hole, the through-hole, and the through-hole and is electrically connected to the connecting portion.

[0038] The heat insulation element covers the pole.

[0039] It is understandable that the electrode post passes through the end cap, the lower plastic layer, and the pin, and is welded to the pin for electrical conductivity. Similarly, the pin is welded to the tab for electrical conductivity, thus achieving electrical connection between the electrode post and the tab. The end heat insulation component covers the electrode post that passes through the perforation to prevent metal debris generated during welding at the connection point from falling into the battery cell, thus preventing short circuits caused by contact with the battery cell. Simultaneously, the smooth surface of the heat insulation component can refract the laser energy generated during laser welding between the connection point and the electrode post, preventing laser energy from affecting the performance of the heat insulation component.

[0040] This application provides an energy storage device, which includes a housing, a battery cell, and an end cap assembly. The housing includes an opening, and the battery cell is mounted in the housing. The battery cell includes a cell body and a tab. The cell body includes a side surface and a top surface connected to the side surface. The tab extends from the side surface and is electrically connected to the cell body. The end cap assembly seals the opening, and the bottom surface faces the top surface. The adapter is stacked with the tab and electrically connected to the tab. The side of the heat insulation member facing away from the pin faces the cell body.

[0041] It is understandable that both the end cap assembly and the battery cell are housed within the casing, with the edge of the end cap connected to the opening edge of the casing via welding or other methods to seal the energy storage device. A heat insulation component is located between the leads and the battery cell to reduce the impact of the large amount of heat generated during the welding of the leads, tabs, and terminals on the battery cell itself. Furthermore, it prevents short circuits caused by contact between the leads and the battery cell itself, and also prevents short circuits caused by metal debris generated during welding of the leads to the terminals and tabs falling into the leads and battery cell itself, thus improving the yield rate of the energy storage device. The heat insulation component blocks heat transfer from the leads and the lower plastic layer to the battery cell itself, reducing the probability of battery cell abnormalities (such as increased internal resistance, self-discharge, and fire) to some extent, ensuring temperature consistency between the first lead and the leads, reducing the risk of lithium metal deposition at the negative electrode, ensuring the safety of the energy storage device, and contributing to a longer overall lifespan.

[0042] This application provides an electrical device that includes the aforementioned energy storage device, which supplies power to the electrical device. Attached Figure Description

[0043] Figure 1 This is a schematic diagram illustrating an application scenario of the energy storage device provided in the embodiments of this application;

[0044] Figure 2 This is a schematic diagram of the structure of the energy storage device provided in the embodiments of this application;

[0045] Figure 3 for Figure 2 The diagram shows the exploded structure of the energy storage device.

[0046] Figure 4 for Figure 3 The diagram shows the structure of the first lower plastic at another angle.

[0047] Figure 5 for Figure 3 The diagram shows the structure of the second lower plastic at another angle;

[0048] Figure 6 for Figure 3 A schematic diagram of the first pin of the end cap assembly in the energy storage device at another angle;

[0049] Figure 7 for Figure 3 A schematic diagram of the second pin of the end cap assembly in the energy storage device at another angle;

[0050] Figure 8 for Figure 3 An exploded structural diagram of a portion of the end cap assembly shown;

[0051] Figure 9 for Figure 8A schematic diagram of a portion of the end cap assembly shown;

[0052] Figure 10 for Figure 2 The diagram shows a cross-sectional view of the energy storage device.

[0053] The terms corresponding to the reference numerals in the figures are as follows: energy storage device 1000, housing 200, opening 201, receiving cavity 202, end cap assembly 100, first lower plastic 10, first body 11, first top surface 111, first bottom surface 112, first boss 13, first boss surface 131, first assembly groove 15, first groove bottom surface 151, first groove peripheral surface 152, first protrusion 16, first protrusion surface 161, first protrusion inner surface 162, first protrusion outer surface 163, first through hole 17, first positioning post 18, second lower plastic 20, second body 21. Second top surface 211, second bottom surface 212, second boss 23, second boss surface 231, second assembly groove 25, second groove bottom surface 251, second groove peripheral surface 252, second protrusion 26, second protrusion surface 261, second protrusion inner surface 262, second protrusion outer surface 263, second through hole 27, second positioning post 28, end cap 30, upper surface 31, lower surface 32, first pole post through hole 33, second pole post through hole 34, first pin 40, first connecting part 41, first outer surface 411, first inner surface 412, first through hole 413, first limit. Hole 414, First adapter 42, First outer surface 421, First inner surface 422, First end face 423, First bend 43, First outer arc surface 431, First inner arc surface 432, Second pin 50, Second connecting part 51, Second outer surface 511, Second inner surface 512, Second through hole 513, Second limiting hole 514, Second adapter 52, Second outer surface 521, Second inner surface 522, Second end face 523, Second bend 53, Second outer arc surface 531, Second inner arc surface 532, First pole post 60, Second pole post 70, Heat insulation Component 80, first side heat insulation component 81, first end heat insulation component 82, first tail heat insulation component 83, second side heat insulation component 84, second end heat insulation component 85, second tail heat insulation component 86, battery cell 300, battery cell body 310, first side surface 311, second side surface 312, top surface 313, first electrode tab 320, second electrode tab 330, first overhang width D1, second overhang width D2, first electrical device 3000, second electrical device 2000, first power conversion device 4100, second power conversion device 4200, energy storage system 5000. Detailed Implementation

[0054] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0055] In this application, unless otherwise expressly specified and limited, the terms “installation,” “connection,” “linking,” “fixing,” etc., shall be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral part; they may refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they may refer to a direct connection or an indirect connection through an intermediate medium; they may refer to the internal connection of two components or the interaction between two components, unless otherwise expressly and specifically limited.

[0056] It should be noted that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include at least one of those features.

[0057] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve energy efficiency, it is necessary to store one form of energy in the same way or by converting it into another, and then release it in a specific energy form according to future application needs. As we all know, to achieve the grand goal of carbon neutrality, the main way to generate green electricity is to develop green energy sources such as photovoltaics and wind power to replace fossil fuels. Currently, the generation of green electricity generally relies on photovoltaics, wind power, and hydropower. However, wind and solar energy generally suffer from strong intermittency and large fluctuations, which can cause grid instability, insufficient electricity during peak demand periods, and excessive electricity during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar curtailment." Solving these problems requires energy storage. Energy storage involves converting electrical energy into other forms of energy through physical or chemical means and storing it. When needed, the stored energy is converted back into electrical energy and released. Simply put, energy storage is like a large "power bank". When there is sufficient solar and wind power, electrical energy is stored and the stored power is released when needed.

[0058] Taking electrochemical energy storage as an example, this application provides an energy storage device 1000. The energy storage device 1000 is equipped with a set of chemical batteries. It mainly uses the chemical elements in the chemical batteries as energy storage medium. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. Simply put, the electrical energy generated by wind and solar energy is stored in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electrical energy is released for use, or transferred to places with a shortage of electricity for use.

[0059] Current energy storage applications are quite widespread, including energy storage on the (wind and solar) power generation side, grid-side energy storage, base station-side energy storage, and user-side energy storage. The corresponding energy storage devices include:

[0060] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, enabling load matching of electrical energy in time and space, enhancing the absorption capacity of renewable energy, and playing a significant role in grid system backup, alleviating peak load power supply pressure, and peak regulation and frequency regulation.

[0061] (2) Small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios (banks, shopping malls, etc.) on the user side mainly operate under the "peak shaving and valley filling" mode. Since there are large price differences in electricity prices at peak and valley times depending on electricity demand, users with energy storage equipment usually charge the energy storage cabinet / box during the low electricity price period in order to reduce costs; and release the electricity in the energy storage equipment for use during the peak electricity price period to achieve the purpose of saving electricity costs.

[0062] It should be noted that the aforementioned energy storage containers, small and medium-sized energy storage cabinets, and household small energy storage boxes, which contain energy storage devices 1000, can be understood as electrical equipment.

[0063] Please see Figure 1 , Figure 1 This is an application scenario diagram of the energy storage device provided in the embodiments of this application.

[0064] The energy storage device 1000 provided in this application embodiment is applied to an energy storage system 5000. The energy storage system 5000 includes a first power conversion device 4100 (photovoltaic panel), a second power conversion device 4200 (wind turbine), a first electrical device 3000 (grid), a second electrical device 2000 (base station), and the energy storage device 1000. The energy storage system 5000 also includes an energy storage cabinet, in which the energy storage device 1000 is installed. The energy storage cabinet can be installed outdoors. Specifically, the first power conversion device 4100 can convert solar energy into electrical energy during periods of low electricity prices. The energy storage device 1000 stores this electrical energy and supplies it to the first electrical device 3000 or the second electrical device 2000 during peak electricity demand periods, or provides power when the first electrical device 3000 or the second electrical device 2000 experiences a power outage. The second power conversion device 4200 can convert wind energy into electrical energy, and the energy storage device 1000 is used to store the electrical energy and supply it to the first electrical device 3000 or the second electrical device 2000 during peak electricity consumption, or to supply power when the first electrical device 3000 or the second electrical device 2000 experiences a power outage. The electrical energy can be transmitted via high-voltage cables.

[0065] It should be noted that the aforementioned first electrical device 3000, second electrical device 2000, and other devices including the energy storage device 1000 can be understood as electrical devices. The energy storage device 1000 supplies power to the electrical devices.

[0066] The number of energy storage devices 1000 can be multiple, and the multiple energy storage devices 1000 can be connected in series or in parallel. In this embodiment, "multiple" means two or more.

[0067] It is understood that the energy storage device 1000 may include, but is not limited to, single-cell batteries, battery modules, battery packs, and battery systems. The actual application form of the energy storage device 1000 provided in this application embodiment may be, but is not limited to, the listed products, and may also be other application forms. For example, the energy storage device 1000 may be a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid (or lead-acid) battery, a lithium-ion battery, a polymer lithium-ion battery, or other rechargeable batteries. When the energy storage device 1000 is a single-cell battery, it may be a cylindrical battery, a prismatic battery, or a battery of other shapes. In this embodiment, the energy storage device 1000 is a prismatic battery. The prismatic battery is a rechargeable battery.

[0068] Please see Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the energy storage device provided in the embodiments of this application. Figure 3 for Figure 2 The diagram shows the exploded structure of the energy storage device.

[0069] For ease of description, the width of the energy storage device 1000 is defined as the X-axis, the length as the Y-axis, and the height as the Z-axis. The X-axis, Y-axis, and Z-axis are all perpendicular to each other.

[0070] The directional terms such as "upper," "top," "lower," "bottom," "left," and "right" mentioned in the embodiments of this application are based on the appendix to the specification. Figure 2 The description of the orientation shown does not constitute a limitation on the actual application scenario of the energy storage device 1000. Specifically, the positive direction towards the Z-axis is considered the top of the energy storage device 1000, and the negative direction towards the Z-axis is considered the bottom of the energy storage device 1000. Furthermore, the terms "same," "equal," or "parallel" used below are all allowed to have certain tolerances.

[0071] like Figure 2 and Figure 3 As shown, the energy storage device 1000 includes a housing 200, an end cap assembly 100, and a battery cell 300. The housing 200 has an opening 201 and a receiving cavity 202. The opening 201 and the receiving cavity 202 are in communication. The battery cell 300 is housed within the receiving cavity 202. The end cap assembly 100 is mounted on one end of the battery cell 300 in the height direction (along the Z-axis direction) and seals it in the opening 201 to isolate the internal environment of the energy storage device 1000 from the external environment. When the housing 200 is a metal housing, the energy storage device 1000 also includes an insulating film (not shown), which is located between the battery cell 300 and the housing 200 to insulate the battery cell 300 from the housing 200 and protect the battery cell 300.

[0072] In this embodiment, the battery cell 300 has a stacked structure to fully utilize the space inside the housing 200, thereby increasing the volumetric energy density of the energy storage device 1000. The battery cell 300 includes a cell body 310 and tabs. The cell body 310 is formed by stacking a positive electrode, a negative electrode, and a separator located between the positive and negative electrode. The separator is used to insulate the positive and negative electrode. Both the positive and negative electrode include a first portion coated with active material and a second portion of uncoated active material extending outward from the first portion. The cell body 310 includes a first side surface 311 and a second side surface 312. Along the length direction (i.e., the Y-axis direction) of the cell body 310, the first side surface 311 and the second side surface 312 are arranged opposite to each other. The cell body 310 also includes a top surface 313. The top surface 313 connects the first side surface 311 and the second side surface 312. The top surface 313 faces the opening 201. In this embodiment, there are two cell bodies 310. Two battery cell bodies 310 are connected side by side along the Y-axis.

[0073] The electrode includes a first electrode 320 and a second electrode 330. Both the first electrode 320 and the second electrode 330 are electrically connected to the cell body 310. The first electrode 320 and the second electrode 330 are symmetrical about the central axis of the cell body 310 in the width direction to ensure the symmetry of the electrode overcurrent position, thereby ensuring the stability of current transmission in the cell 300. Along the Y-axis direction, the first electrode 320 is led out from the first side 311 of the cell body 310. The second electrode 330 is led out from the second side 312 of the cell body 310. In this embodiment, the first electrode 320 can be a positive electrode, and the second electrode 330 can be a negative electrode. The positive electrode corresponds to the second part of the positive electrode sheet that is not coated with active material. The negative electrode corresponds to the second part of the negative electrode sheet that is not coated with active material. There are two of each type of electrode. In other embodiments, the first electrode 320 can be a negative electrode, and the second electrode 330 can be a positive electrode.

[0074] The end cap assembly 100 includes a lower plastic core, an end cap 30, a first pin 40, a second pin 50, a first terminal block 60, a second terminal block 70, and a heat insulation element 80. The lower plastic core and the end cap 30 are stacked along the height direction (i.e., the Z-axis direction) of the energy storage device 1000. The length of the lower plastic core is the same as or approximately the same as the length of the end cap 30. The width of the lower plastic core is the same as or approximately the same as the width of the end cap 30. The first terminal block 60 and the second terminal block 70 are located at opposite ends along the length of the end cap assembly 100. The first terminal block 60 passes through the end cap 30 and the lower plastic core and is connected to the first pin 40. The second terminal block 70 passes through the end cap 30 and the lower plastic core and is connected to the second pin 50. Figure 3As shown, the first pin 40 and the second pin 50 are located at opposite ends of the length direction (i.e., the Y-axis direction) of the cell 300. The first pin 40 is partially mounted on the side of the lower plastic facing away from the end cap 30. The other part of the first pin 40 is stacked with and connected to the first tab 320. The first tab 320 is electrically connected to the first terminal 60 through the first pin 40. The second pin 50 is partially mounted on the side of the lower plastic facing away from the end cap 30. The other part of the second pin 50 is stacked with and connected to the second tab 330. The second tab 330 is electrically connected to the second terminal 70 through the second pin 50. A heat insulation component 80 is stacked on the first pin 40 and the second pin 50. In this embodiment, the end cap 30 is made of aluminum, and the lower plastic is made of plastic and is insulating. A portion of the heat insulation component 80 is disposed between the first pin 40 and the cell body 310, covering the surface of the first pin 40 facing the cell body 310 and part of the surface of the lower plastic. Another portion of the heat insulation element 80 is disposed between the second pin 50 and the cell body 310, and covers the surface of the second pin 50 facing the cell body 310 and part of the surface of the lower plastic. The first terminal 60 is the positive terminal, and the second terminal 70 is the negative terminal. In other embodiments, the first terminal 60 is the negative terminal, and the second terminal 70 is the positive terminal.

[0075] In this embodiment, the end cap 30 is a long strip of thin plate. The end cap 30 includes an upper surface 31 and a lower surface 32. The upper surface 31 and the lower surface 32 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the end cap 30.

[0076] The end cap 30 includes a first pole post through hole 33 and a second pole post through hole 34. Along the thickness direction of the end cap 30, the first pole post through hole 33 extends through the upper surface 31 and the lower surface 32. The first pole post through hole 33 allows the first pole post 60 to pass through. The second pole post through hole 34 extends through the upper surface 31 and the lower surface 32. The second pole post through hole 34 allows the second pole post 70 to pass through. Along the length direction (i.e., the Y-axis direction) of the end cap 30, the first pole post through hole 33 and the second pole post through hole 34 are located at opposite ends of the end cap 30. In this embodiment, both the first pole post through hole 33 and the second pole post through hole 34 are circular holes. In some embodiments, the shapes of the first pole post through hole 33 and the second pole post through hole 34 can also be elliptical, rectangular, etc. This application does not impose strict limitations on these shapes.

[0077] In some embodiments, the upper surface 31 of the end cap 30 is provided with an insulating member (not shown). The insulating member completely covers the upper surface 31 of the end cap 30. The insulating member is used to protect the end cap 30 from scratches that would affect its use.

[0078] The lower plastic includes a first lower plastic 10 and a second lower plastic 20. In this embodiment, the first lower plastic 10 and the second lower plastic 20 are separate structures. In other embodiments, the first lower plastic 10 and the second lower plastic 20 may also be an integral structure.

[0079] Please refer to the following: Figure 3 and Figure 4 , Figure 4 for Figure 3 The diagram shows the structure of the first lower plastic at another angle.

[0080] In this embodiment, the first lower plastic 10 is a long strip of thin sheet. The first lower plastic 10 includes a first body 11. The first body 11 includes a first top surface 111 and a first bottom surface 112. The first top surface 111 and the second bottom surface 112 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the first body 11.

[0081] The first lower plastic 10 also includes a first boss 13. The first boss 13 protrudes from the first bottom surface 112 of the first body 11. The first boss 13 includes a first boss surface 131. The first boss surface 131 faces away from the first body 11 and has the same orientation as the first bottom surface 112. In this embodiment, the first boss 13 is generally a rectangular protrusion.

[0082] The first lower plastic 10 also includes a first mounting groove 15. The first mounting groove 15 is recessed into the first boss surface 131 of the first boss 13 and is recessed towards the first body 11. The first mounting groove 15 is used to accommodate a portion of the first pin 40. The first mounting groove 15 includes a first groove bottom surface 151 and a first groove peripheral surface 152. The orientation of the first groove bottom surface 151 is the same as the orientation of the first bottom surface 112. The first groove peripheral surface 152 surrounds the periphery of the first groove bottom surface 151 and is connected to the first groove bottom surface 151.

[0083] The first lower plastic 10 also includes a first protrusion 16. The first protrusion 16 protrudes from the first bottom surface 112. Along the Y-axis direction, the first boss 13 and the first protrusion 16 are arranged adjacent to each other. It can be understood that along the Y-axis direction, the first protrusion 16 and the first mounting groove 15 are spaced apart. In this embodiment, the first protrusion 16 extends along the X-axis direction. The first protrusion 16 includes a first protruding surface 161. Along the Z-axis direction, the first protruding surface 161 faces away from the first bottom surface 112. In this embodiment, the first protrusion 16 is approximately a rectangular protrusion. The length of the first protrusion 16 (i.e., the dimension along the X-axis direction) is equal to the width of the first boss 13 (i.e., the dimension along the X-axis direction).

[0084] In this embodiment, the distance from the first protruding surface 161 to the first bottom surface 112 is greater than the distance from the first boss surface 131 to the first bottom surface 112. That is, the height of the first protrusion 16 protruding from the first bottom surface 112 of the first body 11 is greater than the height of the first boss 13 protruding from the first bottom surface 112. The first protruding surface 161 and the first boss surface 131 of the first boss 13 are not on the same horizontal plane. The first protrusion 16 also includes an inner surface 162 and an outer surface 163. The inner surface 162 and the outer surface 163 are arranged opposite to each other along the width direction (i.e., the Y-axis direction) of the first protrusion 16, and the inner surface 162 and the outer surface 163 are connected to the first protruding surface 161. The inner surface 162 faces the first boss 13 and is connected to the first boss surface 131. The outer surface 163 faces away from the first boss 13 and is connected to the first bottom surface 112. In fact, the length and width of the first protrusion 16 can be determined according to the length and width requirements of the first boss 13 and the first lower plastic 10. It can be understood that the first protruding surface 161 of the first protrusion 16 can be regarded as the first bottom surface 112.

[0085] In some other embodiments, the distance from the first protruding surface 161 to the first bottom surface 112 is equal to the distance from the first boss surface 131 to the first bottom surface 112. That is, the height of the first protrusion 16 protruding from the first bottom surface 112 is equal to the height of the first boss 13 protruding from the first bottom surface 112. The first protruding surface 161 and the first boss surface 131 of the first boss 13 are flush (i.e., on the same horizontal plane).

[0086] The first lower plastic 10 also includes a first through hole 17. The first through hole 17 penetrates the first groove bottom surface 151 of the first assembly groove 15 and the first top surface 111 of the first body 11. The first through hole 17 is used for the first pole post 60 to pass through. In this embodiment, the first through hole 17 is hexagonal. In some embodiments, the shape of the first through hole 17 can also be circular, elliptical, etc. This application does not impose strict limitations on this.

[0087] The first lower plastic 10 also includes a plurality of first positioning posts 18. The plurality of first positioning posts 18 protrude from the bottom surface 151 of the first mounting groove 15. The first positioning posts 18 are spaced apart at the periphery of the first through hole 17, and the plurality of first positioning posts 18 are spaced apart from each other. The first positioning posts 18 are used for assembling and positioning the first pin 40. In this embodiment, the first positioning posts 18 are cylindrical. The number of first positioning posts 18 is two.

[0088] In some other embodiments, the first lower plastic 10 further includes a first mounting groove (not shown). The first mounting groove is recessed on the first boss surface 131 of the first boss 13 and is recessed towards the first body 11. The first mounting groove is used to accommodate at least part of the heat insulation member 80 to reduce the space occupied by the heat insulation member 80 in the thickness direction of the end cap assembly 100. The first mounting groove includes a first groove sidewall and a first groove bottom wall. The orientation of the first groove bottom wall is the same as the orientation of the first bottom surface 112. The first groove sidewall surrounds the periphery of the first groove bottom wall and is connected to the first groove bottom wall. The first assembly groove 15 is recessed in the first groove bottom wall and is recessed towards the first top surface 111. It can be understood that the groove opening orientation of the first assembly groove 15 is consistent with the groove opening orientation of the first mounting groove. Along the Z-axis direction, the orthographic projection of the first assembly groove 15 on the first lower plastic 10 falls within the orthographic projection range of the first mounting groove on the first lower plastic 10. The first protrusion 16 is adjacent to and connected to the first mounting groove. The inner side 162 of the first protrusion 16 forms the wall surface of the first groove sidewall facing the bottom wall of the first groove.

[0089] Please refer to the following: Figure 3 and Figure 5 , Figure 5 for Figure 3 The diagram shows the structure of the second lower plastic at another angle.

[0090] In this embodiment, the structure of the second lower plastic 20 is similar to that of the first lower plastic 10. The second lower plastic 20 is a long strip of thin sheet. The second lower plastic 20 includes a second body 21. The second body 21 includes a second top surface 211 and a second bottom surface 212. The second top surface 211 and the second bottom surface 212 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the second body 21.

[0091] The second lower plastic 20 also includes a second boss 23. The second boss 23 protrudes from the second bottom surface 212 of the second body 21. The second boss 23 includes a second boss surface 231. The second boss surface 231 faces away from the second body 21 and has the same orientation as the second bottom surface 212. In this embodiment, the second boss 23 is generally a rectangular protrusion.

[0092] The second lower plastic 20 also includes a second mounting groove 25. The second mounting groove 25 is recessed into the second boss surface 231 of the second boss 23 and is recessed towards the second body 21. The second mounting groove 25 is used to accommodate a portion of the second pin 50. The second mounting groove 25 includes a second groove bottom surface 251 and a second groove peripheral surface 252. The orientation of the second groove bottom surface 251 is the same as the orientation of the second bottom surface 212. The second groove peripheral surface 252 surrounds the periphery of the second groove bottom surface 251 and is connected to the second groove bottom surface 251.

[0093] The second lower plastic 20 also includes a second protrusion 26. The second protrusion 26 protrudes from the second bottom surface 212. Along the Y-axis direction, the second boss 23 and the second protrusion 26 are arranged adjacent to each other. It can be understood that along the Y-axis direction, the second protrusion 26 and the second mounting groove 25 are spaced apart. In this embodiment, the second protrusion 26 extends along the X-axis direction. The second protrusion 26 includes a second protruding surface 261. Along the Z-axis direction, the second protruding surface 261 faces away from the second bottom surface 212. In this embodiment, the second protrusion 26 is approximately a rectangular protrusion. The length of the second protrusion 26 (i.e., the dimension along the X-axis direction) is greater than the width of the second boss 23 (i.e., the dimension along the X-axis direction).

[0094] In this embodiment, the distance from the second protruding surface 261 to the second bottom surface 212 is greater than the distance from the second boss surface 231 to the second bottom surface 212. That is, the height of the second protrusion 26 protruding from the second bottom surface 212 of the second body 21 is greater than the height of the second boss 23 protruding from the second bottom surface 212. The second protruding surface 261 and the second boss surface 231 of the second boss 23 are not on the same horizontal plane. The second protrusion 26 also includes a second inner surface 262 and a second outer surface 263. The second inner surface 262 and the second outer surface 263 are arranged opposite to each other along the width direction (i.e., the Y-axis direction) of the second protrusion 26, and the second inner surface 262 and the second outer surface 263 are connected to the second protruding surface 261. The second inner surface 262 faces the second boss 23 and is connected to the second boss surface 231. The second outer surface 263 faces away from the second protrusion 26 and is connected to the second bottom surface 212. In fact, the length and width of the second protrusion 26 can be determined according to the length and width requirements of the second boss 23 and the second lower plastic 20. It can be understood that the second protruding surface 261 of the second protrusion 26 can be regarded as the second bottom surface 212.

[0095] In some embodiments, the distance from the second protruding surface 261 to the second bottom surface 212 is equal to the distance from the second boss surface 231 to the second bottom surface 212. That is, the height of the second protrusion 26 protruding from the second bottom surface 212 is equal to the height of the second boss 23 protruding from the second bottom surface 212. The second protruding surface 261 and the second boss surface 231 of the second boss 23 are flush (i.e., on the same horizontal plane).

[0096] The second lower plastic 20 also includes a second through hole 27. The second through hole 27 penetrates the second groove bottom surface 251 of the second assembly groove 25 and the second top surface 211 of the second body 21. The second through hole 27 is used for the second pole post 70 to pass through. In this embodiment, the shape of the second through hole 27 is hexagonal. In some embodiments, the shape of the second through hole 27 can also be circular, elliptical, etc. This application does not impose strict limitations on this.

[0097] The second lower plastic 20 also includes a plurality of second positioning posts 28. Each of the second positioning posts 28 protrudes from the bottom surface 251 of the second mounting groove 25. The second positioning posts 28 are spaced apart from each other around the periphery of the second through hole 27. The second positioning posts 28 are used for assembling and positioning the second pin 50. In this embodiment, the second positioning posts 28 are cylindrical. There are two second positioning posts 28.

[0098] In some other embodiments, the second lower plastic 20 further includes a second mounting groove (not shown). The second mounting groove is recessed on the second boss surface 231 of the second boss 23 and is recessed towards the second body 21. The second mounting groove is used to accommodate at least part of the heat insulation member 80 to reduce the space occupied by the heat insulation member 80 in the thickness direction of the end cap assembly 100. The second mounting groove includes a second groove sidewall and a second groove bottom wall. The orientation of the second groove bottom wall is the same as the orientation of the second bottom surface 212. The second groove sidewall surrounds the periphery of the second groove bottom wall and is connected to the second groove bottom wall. The second assembly groove 25 is recessed in the second groove bottom wall and is recessed towards the second top surface 211. It can be understood that the groove opening orientation of the second assembly groove 25 is consistent with the groove opening orientation of the second mounting groove. Along the Z-axis direction, the orthographic projection of the second assembly groove 25 on the second lower plastic 20 falls within the orthographic projection range of the second mounting groove on the second lower plastic 20. The second protrusion 26 is adjacent to and connected to the second mounting groove. The inner side 262 of the second protrusion 26 forms the wall surface of the second mounting groove facing the bottom wall of the second groove.

[0099] Please see Figure 6 , Figure 6 for Figure 3 The diagram shows the structure of the first pin of the end cap assembly in the energy storage device at another angle.

[0100] In this embodiment, the first pin 40 is a metal sheet. The first pin 40 includes a first connecting portion 41, a first adapter portion 42, and a first bending portion 43. The first bending portion 43 connects the first connecting portion 41 and the first adapter portion 42. The extending direction of the first connecting portion 41 and the extending direction of the first adapter portion 42 form an angle. The first connecting portion 41 is used to be accommodated in the first assembly groove 15 of the first lower plastic 10 and is used to be fixed and electrically connected to the first electrode post 60 by welding. The first adapter portion 42 is used to be fixed and electrically connected to the first electrode tab 320 of the battery cell 300 by welding. That is, the first pin 40 is used to transfer the current of the battery cell 300 to the first electrode post 60 in sequence through the first adapter portion 42, the first bending portion 43, and the first connecting portion 41. It can be understood that the first pin 40 is approximately an L-shaped bent structure. The first connecting portion 41 and the first adapter portion 42 are located on different planes.

[0101] Specifically, the first connecting portion 41 includes a first outer surface 411 and a first inner surface 412. The first outer surface 411 and the first inner surface 412 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the first connecting portion 41. The first inner surface 412 is used to connect with the heat insulation member 80.

[0102] The first connecting portion 41 further includes a first through hole 413. The first through hole 413 extends through the first outer surface 411 and the first inner surface 412. The first through hole 413 is used for the first pole post 60 to pass through. The wall of the first through hole 413 is connected to the first pole post 60. In this embodiment, the shape of the first connecting portion 41 matches the shape of the first mounting groove 15. The first through hole 413 is a circular hole. In some embodiments, the shape of the first through hole 413 can also be rectangular, elliptical, or other shapes. This application does not impose strict limitations on this.

[0103] The first connecting portion 41 also has a plurality of first limiting holes 414. The plurality of first limiting holes 414 all penetrate the first outer surface 411 and the first inner surface 412. The first limiting holes 414 are spaced apart at the periphery of the first through hole 413, and the plurality of first limiting holes 414 are spaced apart from each other. Each first limiting hole 414 is used for a first positioning post 18 of the first lower plastic 10 to pass through. In this embodiment, the number and shape of the first limiting holes 414 match the number and shape of the first positioning posts 18, respectively. The shape of the first limiting hole 414 is circular. The number of first limiting holes 414 is two.

[0104] In this embodiment, the first adapter portion 42 is a rectangular sheet. The first adapter portion 42 includes a first outer surface 421, a first inner surface 422, and a first end face 423. The first outer surface 421 and the first inner surface 422 are arranged opposite to each other along the thickness direction (along the Y-axis direction) of the first adapter portion 42. Along the Y-axis direction, the first outer surface 421 faces away from the first connecting portion 41 and is used to connect with the first tab 320. The first end face 423 connects the first outer surface 421 and the first inner surface 422. Along the Z-axis direction, the first end face 423 is away from the first connecting portion 41. Both the first inner surface 422 and the first end face 423 are used to connect with the heat insulation member 80.

[0105] In some embodiments, the first transition portion 42 further includes a thinning region (not shown in the figures). The thinning region is a region where the thickness of the first transition portion 42 is reduced. The thinning region is located at the end of the first transition portion 42 away from the first connecting portion 41. By thinning the thinning region, the local thickness of the first transition portion 42 is reduced, thereby reducing the heat conduction capacity of the thinning region.

[0106] The first bend 43 includes a first outer arc surface 431 and a first inner arc surface 432. The first outer arc surface 431 and the first inner arc surface 432 are disposed opposite to each other along the thickness direction of the first bend 43. The first outer arc surface 431 connects the first outer surface 411 and the first outer side surface 421. The first inner arc surface 432 connects the first inner surface 412 and the first inner side surface 422. The first inner arc surface 432 is used to connect with the heat insulation member 80.

[0107] Please see Figure 7 , Figure 7 for Figure 3 The diagram shows the second pin of the end cap assembly in the energy storage device at another angle.

[0108] In this embodiment, the structure of the second pin 50 is similar to that of the first pin 40. The second pin 50 is a metal sheet. The second pin 50 includes a second connecting portion 51, a second adapter portion 52, and a second bending portion 53. The second bending portion 53 is connected to the second connecting portion 51 and the second adapter portion 52. The second connecting portion 51 is used to be accommodated in the second assembly groove 25 of the second lower plastic 20 and is used to be fixed and electrically connected to the second electrode post 70 by welding. The second adapter portion 52 is used to be fixed and electrically connected to the second electrode tab 330 of the battery cell 300 by welding. That is, the second pin 50 is used to transfer the current of the battery cell 300 to the second electrode post 70 in sequence through the second adapter portion 52, the second bending portion 53, and the second connecting portion 51. It can be understood that the second pin 50 is approximately an L-shaped bent structure. The second connecting portion 51 and the second adapter portion 52 are located on different planes.

[0109] Specifically, the second connecting portion 51 includes a second outer surface 511 and a second inner surface 512. The second outer surface 511 and the second inner surface 512 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the second connecting portion 51. The second inner surface 512 is used to connect with the heat insulation member 80.

[0110] The second connecting portion 51 further includes a second through hole 513. The second through hole 513 extends through the second outer surface 511 and the second inner surface 512. The second through hole 513 is used for the second pole post 70 to pass through. The wall of the second through hole 513 is connected to the second pole post 70. In this embodiment, the shape of the second connecting portion 51 matches the shape of the second mounting groove 25. The second through hole 513 is a circular hole. In some embodiments, the shape of the second through hole 513 can also be rectangular, elliptical, or other shapes. This application does not impose strict limitations on this.

[0111] The second connecting portion 51 also has a plurality of second limiting holes 514. The plurality of second limiting holes 514 all penetrate the second outer surface 511 and the second inner surface 512. The second limiting holes 514 are spaced apart at the periphery of the second through hole 513, and the plurality of second limiting holes 514 are spaced apart from each other. Each second limiting hole 514 is used for one of the second positioning posts 28 of the second lower plastic 20 to pass through. In this embodiment, the number and shape of the second limiting holes 514 match the number and shape of the second positioning posts 28, respectively. The shape of the second limiting hole 514 is circular. The number of second limiting holes 514 is two.

[0112] In this embodiment, the second adapter portion 52 is a rectangular sheet. The second adapter portion 52 includes a second outer surface 521, a second inner surface 522, and a second end face 523. The second outer surface 521 and the second inner surface 522 are arranged opposite to each other along the thickness direction (along the Y-axis direction) of the second adapter portion 52. Along the Y-axis direction, the second outer surface 521 faces away from the second connecting portion 51 and is used to connect with the second tab 330. The second end face 523 connects the second outer surface 521 and the second inner surface 522. Along the Z-axis direction, the second end face 523 is away from the second connecting portion 51. Both the second inner surface 522 and the second end face 523 are used to connect with the heat insulation member 80.

[0113] In some embodiments, the second transition portion 52 further includes a thinning region (not shown). The thinning region is a region where the thickness of the second transition portion 52 is reduced. The thinning region is located at the end of the second transition portion 52 away from the second connecting portion 51. By thinning the thinning region, the local thickness of the second transition portion 52 is reduced, thereby reducing the heat conduction capacity of the thinning region.

[0114] The second bend 53 includes a second outer arc surface 531 and a second inner arc surface 532. The second outer arc surface 531 and the second inner arc surface 532 are disposed opposite to each other along the thickness direction of the second bend 53. The second outer arc surface 531 connects the second outer surface 511 and the second outer side surface 521. The second inner arc surface 532 connects the second inner surface 512 and the second inner side surface 522. The second inner arc surface 532 is used to connect with the heat insulation member 80.

[0115] Please refer to both together. Figure 3 , Figure 8 and Figure 9 , Figure 8 for Figure 3 The diagram shown is an exploded view of a portion of the end cap assembly. Figure 9 for Figure 8 The diagram shows a partial structural representation of the end cap assembly. It should be noted that... Figure 8 The area between the two closely spaced dashed lines is the overlapping portion between two adjacent insulation components. Figure 9 The dashed line in the image represents the boundary line of the first pin of the first heat insulation component. Figure 8 The diagram illustrates the assembly structure of the pins, heat insulation components, and lower plastic parts. Figure 9 The assembly structure of the first pin, the first heat insulation component, and the first lower plastic component is illustrated as an example. The assembly structure of the second pin, the second heat insulation component, and the second lower plastic component is similar. Figure 9 The assembly structure of the first pin, the first heat insulation component, and the first lower plastic component shown is the same, therefore in Figure 9 No illustration is provided.

[0116] In this embodiment, the first pin 40 is mounted on the first lower plastic 10. The first connecting portion 41 of the first pin 40 is housed within the first mounting groove 15 of the first lower plastic 10. The first outer surface 411 of the first connecting portion 41 is connected to the first groove bottom surface 151 of the first mounting groove 15. Two first positioning posts 18 are respectively disposed through the two first limiting holes 414 of the first connecting portion 41 to limit and fix the first pin 40 onto the first lower plastic 10. The first through hole 413 of the first connecting portion 41 is coaxially arranged with the first through hole 17 of the first lower plastic 10. Along the Y-axis direction, the first inner surface 422 of the first adapter portion 42 is opposite to and spaced from the first protrusion 16. The first adapter portion 42 extends away from the first lower plastic 10.

[0117] The second pin 50 is mounted on the second lower plastic 20. The second connecting portion 51 of the second pin 50 is housed within the second mounting groove 25 of the second lower plastic 20. The second outer surface 511 of the second connecting portion 51 is connected to the bottom surface 251 of the second mounting groove 25. Two second positioning pins 28 are respectively inserted through the two second limiting holes 514 of the second connecting portion 51 to limit and fix the second pin 50 onto the second lower plastic 20. The second through hole 513 of the second connecting portion 51 is coaxially arranged with the second through hole 27 of the second lower plastic 20. Along the Y-axis direction, the second inner surface 522 of the second adapter portion 52 is opposite to and spaced from the second protrusion 26. The second adapter portion 52 extends away from the second lower plastic 20.

[0118] In this embodiment, the heat insulation component 80 is characterized by its smoothness, resistance to displacement, high temperature resistance, small size, non-reaction with the electrolyte, and ability to block heat conduction. The smooth surface of the heat insulation component 80 can promote the flow of electrolyte near the heat insulation component 80. The heat insulation component 80 can be made of heat-insulating and non-detachable materials such as polyimide tape, Teflon tape, or Teflon coating. For example, the heat insulation component 80 is a high-temperature adhesive.

[0119] The heat insulation component 80 includes a first side heat insulation component 81, a first end heat insulation component 82, a first tail heat insulation component 83, a second side heat insulation component 84, a second end heat insulation component 85, and a second tail heat insulation component 86. Specifically, the first side heat insulation component 81, the first end heat insulation component 82, and the first tail heat insulation component 83 cover the first pin 40 and a portion of the first lower plastic 10. The second side heat insulation component 84, the second end heat insulation component 85, and the second tail heat insulation component 86 cover the second pin 50 and a portion of the second lower plastic 20.

[0120] Combination Figure 8 and Figure 9 As shown, the first side heat insulation member 81 and the first end heat insulation member 82 partially overlap to form a thickened area, and the first side heat insulation member 81 and the first tail heat insulation member 83 partially overlap to form a thickened area. The second side heat insulation member 84 and the second end heat insulation member 85 partially overlap to form a thickened area, and the second side heat insulation member 84 and the second tail heat insulation member 86 partially overlap to form a thickened area.

[0121] In this embodiment, the first side heat insulation member 81 covers the first inner surface 422 of the first transition portion 42 and the first inner arc surface 432 of the first bend portion 43. The first side heat insulation member 81 is used to separate the first transition portion 42 and the first bend portion 43 from the cell body 310, so as to avoid the first transition portion 42 and the first bend portion 43 from the separator between the positive and negative electrode plates in the cell body 310, which would cause defects such as thermal shrinkage, melting, and damage to the separator, and prevent the positive and negative electrode plates from directly contacting each other, thereby preventing a short circuit in the cell. The length (i.e., the dimension along the Z-axis) of the first side heat insulation member 81 is 100 mm, and the width (i.e., the dimension along the X-axis) is 55 mm. The length and width of the first side heat insulation member 81 can also be determined according to the actual application. This application does not impose strict limitations on this.

[0122] In this embodiment, the first end heat insulation member 82 covers the first inner surface 412 of the first connecting portion 41 and the first inner arc surface 432 of the first bent portion 43. The first end heat insulation member 82 is used to separate the first bent portion 43 and the first connecting portion 41 from the cell body 310, so as to avoid the first connecting portion 41 and the first bent portion 43 from the separator between the positive and negative electrode plates in the cell body 310, which would cause defects such as thermal shrinkage, melting, and damage to the separator, and prevent the positive and negative electrode plates from directly contacting each other, thereby preventing a short circuit in the cell. The length (i.e., the dimension along the Y-axis) of the first end heat insulation member 82 is 59 mm, and the width (i.e., the dimension along the X-axis) is 55 mm. The length and width of the first end heat insulation member 82 can also be determined according to the actual application. This application does not impose strict limitations on this.

[0123] When the first protrusion 16 protrudes from the first boss 13 relative to the first bottom surface 112, the inner surface 162 of the first protrusion 16 is connected to the first boss surface 131. The first end heat insulation member 82 not only covers the first inner surface 412 of the first connecting part 41 and the first inner arc surface 432 of the first bending part 43, but also covers and connects the first boss surface 131 around the first connecting part 41. The edge of the first end heat insulation member 82 away from the first side heat insulation member 81 is adhered to the inner surface 162 of the first protrusion. This not only increases the contact area between the first end heat insulation member 82 and the first lower plastic 10, reduces the instability of the first end heat insulation member 82 when it is impacted by the electrolyte, and improves the adhesion effect of the first end heat insulation member 82 on the first lower plastic 10, but also the inner surface 162 of the first protrusion also plays a limiting role in the adhesion of the first end heat insulation member 82, thereby improving the adhesion rate of the first end heat insulation member 82.

[0124] In some embodiments, the first end heat insulation member 82 not only covers the first inner surface 412 of the first connecting portion 41 and the first inner arc surface 432 of the first bending portion 43, but also covers and connects the first protruding surface 161 of the first protrusion 16 and the first boss surface 131 of the first boss 13, further increasing the contact area between the first end heat insulation member 82 and the first lower plastic 10, and improving the adhesion effect of the first end heat insulation member 82 on the first lower plastic 10.

[0125] In some embodiments, the first end heat insulation member 82 covers not only the first inner surface 412 of the first connecting portion 41 and the first inner arc surface 432 of the first bend portion 43, but also the first boss surface 131 of the first boss 13, the first protrusion surface 161 of the first protrusion 16, and the outer surface 163 of the first protrusion. Even in some embodiments, the end of the first end heat insulation member 82 away from the first side heat insulation member 81 can extend beyond the first boss 13 to connect with the first bottom surface 112, effectively blocking heat conduction between the first pin 40 and the cell body 310.

[0126] It should be noted that, for example Figure 9As shown, the width of the first end heat insulation member 82 is greater than the width of the first connecting portion 41 of the first pin 40. Along the width direction of the first lower plastic 10, the width of the first end heat insulation member 82 extending beyond the first connecting portion 41 is a first overhang width D1. It can be understood that along the width direction of the first lower plastic 10, the first end heat insulation member 82 completely covers the first inner surface 412 of the first connecting portion 41 and the first boss surface 131 near the first connecting portion 41, so as to completely separate the first lower plastic 10 from the cell body 310, block the heat conduction between the first pin 40 and the portion of the first lower plastic 10 near the first pin 40 and the cell body 310, and avoid the influence of high temperature on the cell 300. In some embodiments, the width of the first end heat insulation member 82 may be greater than the width of the first boss 13. The first end heat insulation member 82 not only covers the first inner surface 412 and the first boss surface 131, but also covers the first bottom surface 112 of the first lower plastic 10 on the side of the first boss 13 facing away from the first mounting groove 15. The contact area between the first end heat insulation member 82 and the first lower plastic 10 is further increased, which is more conducive to separating the first lower plastic 10 from the cell body 310, so as to maximize the blocking of heat conduction from the first pin 40 and the first lower plastic 10 near the first pin 40 to the direction of the cell body 300, and further avoid the influence of high temperature on the cell 300.

[0127] Because the thermal conductivity from the first pin 40 to the first lower plastic 10 is poor, and the thermal conductivity from the first pin 40 to the cell body 310 is good, the width of the thickened area formed by the overlap of the first end heat insulation member 82 and the first side heat insulation member 81 needs to be greater than the first excess width D1. For example, the ratio of the width of the thickened area formed by the overlap of the first end heat insulation member 82 and the first side heat insulation member 81 to the first excess width D1 is greater than or equal to 1.1 and less than or equal to 3. This not only sufficiently avoids thermal conduction between the first bent portion 43 and the cell body 310, but also avoids using too much material in the heat insulation member 80, thus preventing waste.

[0128] In addition, the length of the thickened area formed by the overlap of the first end heat insulation member 82 and the first side heat insulation member 81 is greater than the length of the first inner arc surface 432, and the ratio of the area of ​​the thickened area to the area of ​​the first inner arc surface 432 is greater than or equal to 1.2 and less than or equal to 5, so as to further effectively isolate the heat conduction between the first pin 40 and the cell body 310.

[0129] Furthermore, the first end heat insulation member 82 covers the first connecting part 41 and the gap between the first connecting part 41 and the first assembly groove 15, preventing the electrolyte from penetrating and adhering to the first connecting part 41 and the gap between the first connecting part 41 and the first assembly groove 15, thus ensuring the stability of the electrolyte.

[0130] In this embodiment, the first tail heat insulation member 83 covers the first end face 423 of the first adapter portion 42 and part of the first inner surface 422 of the first adapter portion 42. The first tail heat insulation member 83 is used to better separate the cell body 310 and the first tab 320 and block the heat conduction of the first tab 320 to the cell body 310 through the first adapter portion 42.

[0131] In this embodiment, the first side heat insulation member 81 and the first end heat insulation member 82 partially overlap. The overlapping portion of the first side heat insulation member 81 and the first end heat insulation member 82 covers the first bend portion 43. It can be understood that the overlapping portion of the first side heat insulation member 81 and the first end heat insulation member 82 increases the thickness of the high-temperature adhesive and forms a thickened area, which completely covers the first inner arc surface 432 of the first bend portion 43.

[0132] In some other embodiments, the first side heat insulation member 81 may also cover a portion of the first inner surface 412 of the first connecting portion 41, and the first end heat insulation member 82 may also cover a portion of the first inner surface 422 of the first transition portion 42. Therefore, the overlapping portion of the first side heat insulation member 81 and the first end heat insulation member 82 covers not only the first bend portion 43, but also a portion of the first transition portion 42 and a portion of the first connecting portion 41. It can be understood that the thickened areas of the first side heat insulation member 81 and the first end heat insulation member 82 completely cover the first inner arc surface 432 connecting the first bend portion 43, a portion of the first inner surface 422 on both sides of the first inner arc surface 432, and a portion of the first inner surface 412.

[0133] In some other embodiments, the first end heat insulation member 82 may also cover a portion of the first inner surface 422 of the first transition portion 42. Therefore, the overlapping portion of the first side heat insulation member 81 and the first end heat insulation member 82, in addition to covering the first bend portion 43, may also cover a portion of the first transition portion 42. It can be understood that the thickened areas of the first side heat insulation member 81 and the first end heat insulation member 82 completely cover the first inner arc surface 432 of the first bend portion 43 and a portion of the first inner surface 422 on one side of the first inner arc surface 432.

[0134] In some other embodiments, the first side heat insulation member 81 may also cover a portion of the first inner surface 412 of the first connecting portion 41. Therefore, the overlapping portion of the first side heat insulation member 81 and the first end heat insulation member 82 covers not only the first bend portion 43 but also a portion of the first connecting portion 41. It can be understood that the thickened areas of the first side heat insulation member 81 and the first end heat insulation member 82 completely cover the first inner arc surface 432 of the first bend portion 43 and a portion of the first inner surface 412 on the other side of the first inner arc surface 432.

[0135] In this embodiment, the first side heat insulation member 81 also partially overlaps with the first tail heat insulation member 83. The overlapping portion of the first side heat insulation member 81 and the first tail heat insulation member 83 covers the first inner surface 422 of the first transition portion 42. It can be understood that the overlapping portion of the first side heat insulation member 81 and the first tail heat insulation member 83 increases the thickness of the high-temperature adhesive and forms a thickened area, which completely covers the first inner surface 422 of the first transition portion 42.

[0136] In some other embodiments, the first side heat insulation member 81 may also cover a portion of the first end face 423 of the first transition portion 42, and the overlapping portion of the first side heat insulation member 81 and the first tail heat insulation member 83 may cover not only the first inner side surface 422 of the first transition portion 42, but also the first end face 423. It can be understood that the thickened areas of the first side heat insulation member 81 and the first tail heat insulation member 83 completely cover the first inner side surface 422 and the first end face 423 of the first transition portion 42.

[0137] In some other embodiments, the first tail heat insulation member 83 only covers the first end face 423 of the first transition portion 42, and the first side heat insulation member 81 covers not only the first inner side face 422 of the first transition portion 42, but also a portion of the first end face 423 of the first transition portion 42. The overlapping portion of the first side heat insulation member 81 and the first tail heat insulation member 83 covers the first end face 423 of the first transition portion 42. It can be understood that the thickened areas of the first side heat insulation member 81 and the first tail heat insulation member 83 completely cover the first end face 423 of the first transition portion 42.

[0138] It should be noted that the first side heat insulation member 81, the first end heat insulation member 82, and the first tail heat insulation member 83 can be integrally formed, or they can be separately formed to adapt to different needs in actual production applications. In some embodiments, the heat insulation member 80 includes the first end heat insulation member 82 and the first side heat insulation member 81. The first end heat insulation member 82 and the first side heat insulation member 81 are integrally formed, or they are separately formed. The end of the first side heat insulation member 81 away from the first end heat insulation member 82 extends to the first end face 423 of the first transition portion 42, and the first side heat insulation member 81 covers the first inner surface 422 and at least part of the first end face 423. This application does not impose strict limitations on this.

[0139] It is understood that the heat insulation component 80 includes a thickened area. The thickened area can be understood as the region where the thickness of the heat insulation component 80 is increased. The thickened area of ​​the heat insulation component 80 covering the first pin 40 can completely cover the first inner arc surface 432 of the first bend 43. Alternatively, the thickened area of ​​the heat insulation component 80 covering the first pin 40 can completely cover the first inner arc surface 432 of the first bend 43, as well as a portion of the first inner surface 422 and a portion of the first inner surface 412 connecting both sides of the first inner arc surface 432. Alternatively, the thickened area of ​​the heat insulation component 80 covering the first pin 40 can completely cover the first inner arc surface 432 of the first bend 43, as well as a portion of the first inner surface 422 connecting one side of the first inner arc surface 432. Alternatively, the thickened area of ​​the heat insulation component 80 can completely cover the first inner arc surface 432 of the first bend 43, as well as a portion of the first inner surface 412 connecting one side of the first inner arc surface 432.

[0140] In this embodiment, the second side heat insulation member 84 covers the second inner surface 522 of the second transition portion 52 and the second inner arc surface 532 of the second bend portion 53. The second side heat insulation member 84 is used to separate the second transition portion 52 and the second bend portion 53 from the cell body 310, to avoid contact between the second transition portion 52 and the second bend portion 53 and the separator between the positive and negative electrode plates in the cell body 310, which could lead to defects such as thermal shrinkage, melting, and damage to the separator, and to prevent direct contact between the positive and negative electrode plates, thus avoiding a short circuit in the cell. The length (i.e., the dimension along the Z-axis) of the second side heat insulation member 84 is 100 mm, and the width (i.e., the dimension along the X-axis) is 35 mm. The length and width of the second side heat insulation member 84 can also be determined according to actual application conditions. This application does not impose strict limitations on this.

[0141] In this embodiment, the second end heat insulation member 85 covers the second inner surface 512 of the second connecting portion 51 and the second inner arc surface 532 of the second bending portion 53. The second end heat insulation member 85 is used to separate the second bending portion 53, the second connecting portion 51 and the cell body 310, so as to avoid the contact between the separator between the positive electrode and the negative electrode in the second connecting portion 51 and the second bending portion 53 and the cell body 310, which would cause defects such as thermal shrinkage, melting, and damage to the separator, and prevent the positive electrode and the negative electrode from directly contacting each other, thereby preventing a short circuit in the cell. The length (i.e., the dimension along the Y-axis) of the second end heat insulation member 85 is 44 mm and the width (i.e., the dimension along the X-axis) is 35 mm. The length and width of the second end heat insulation member 85 can also be determined according to the actual application. This application does not impose strict limitations on this.

[0142] When the second protrusion 26 protrudes beyond the second boss 23 relative to the second bottom surface 212, and the inner surface 262 of the second protrusion 26 is connected to the second boss surface 231, the second end heat insulation member 85 not only covers the second inner surface 512 of the second connecting portion 51 and the second inner arc surface 532 of the second bending portion 53, but also covers and connects the second boss surface 231 around the second connecting portion 51. The edge of the second end heat insulation member 85 away from the second side heat insulation member 84 is adhered to the inner surface 262 of the second protrusion. This not only increases the contact area between the second end heat insulation member 85 and the second lower plastic 20, reduces the instability of the second end heat insulation member 85 when it is impacted by the electrolyte, and improves the adhesion effect of the second end heat insulation member 85 on the second lower plastic 20, but also the inner surface 262 of the second protrusion plays a limiting role in the adhesion of the second end heat insulation member 85, thereby improving the adhesion rate of the second end heat insulation member 85.

[0143] In some embodiments, the second end heat insulation member 85 covers not only the second inner surface 512 of the second connecting portion 51 and the second inner arc surface 532 of the second bending portion 53, but also the second protrusion surface 231 of the second protrusion surface 261 and the second protrusion surface 231 of the second protrusion 23, thereby further increasing the contact area between the second end heat insulation member 85 and the second lower plastic 20 and improving the adhesion effect of the second end heat insulation member 85 on the second lower plastic 20.

[0144] In some embodiments, the second end heat insulation member 85 covers not only the second inner surface 512 of the second connecting portion 51 and the second inner arc surface 532 of the second bend portion 53, but also the second boss surface 231 of the second boss 23, the second protrusion surface 261 of the second protrusion 26, and the outer side surface 263 of the second protrusion. Even in some embodiments, the end of the second end heat insulation member 85 away from the second side heat insulation member 84 can extend beyond the second boss 23 to connect with the first bottom surface 112, effectively blocking heat conduction between the second pin 50 and the cell body 310.

[0145] It should be noted that the width of the second end heat insulation member 85 is greater than the width of the second connecting portion 51 of the second pin 50. Along the width direction of the second lower plastic 20, the width of the second end heat insulation member 85 extending beyond the second connecting portion 51 is the second excess width D2. It can be understood that along the width direction of the second lower plastic 20, the second end heat insulation member 85 completely covers the second inner surface 512 of the second connecting portion 51 and the second boss surface 231 within the negative electrode of the second connecting portion 51, so as to completely separate the second lower plastic 20 from the cell body 310, block the heat conduction between the second pin 50 and the portion of the second lower plastic 20 near the second pin 50 and the cell body 310, and avoid the influence of high temperature on the cell 300. In some embodiments, the width of the second end heat insulation member 85 may be greater than the width of the second boss 23. The second end heat insulation member 85 not only covers the second inner surface 512 and the second boss surface 231, but also covers the second bottom surface 212 of the second lower plastic 20 on the side of the second boss 23 facing away from the second mounting groove 25. The contact area between the second end heat insulation member 85 and the second lower plastic 20 is further increased, which is more conducive to separating the second lower plastic 20 from the cell body 310, so as to maximize the blocking of heat conduction from the second pin 50 and the second lower plastic 20 near the second pin 50 to the cell body 300, and further avoid the influence of high temperature on the cell 300.

[0146] Because the thermal conductivity from the second pin 50 to the second lower plastic 20 is poor, and the thermal conductivity from the second pin 50 to the cell body 310 is good, the width of the thickened area formed by the overlap of the second end heat insulation member 85 and the second side heat insulation member 84 needs to be greater than the second excess width D2. For example, the ratio of the width of the thickened area formed by the overlap of the second end heat insulation member 85 and the second side heat insulation member 84 to the second excess width D2 is greater than or equal to 1.1 and less than or equal to 3. This not only sufficiently avoids thermal conduction between the second bend 53 and the cell body 310, but also avoids using too much material in the heat insulation member 80, thus preventing waste.

[0147] Furthermore, the length of the thickened area formed by the overlap of the second end heat insulation member 85 and the second side heat insulation member 84 is greater than the length of the second inner arc surface 532, and the ratio of the area of ​​the thickened area to the area of ​​the second inner arc surface 532 is greater than or equal to 1.2 and less than or equal to 5, so as to further effectively isolate the heat conduction between the second pin 50 and the cell body 310.

[0148] Furthermore, the second end heat insulation member 85 covers the second connecting part 51 and the gap between the second connecting part 51 and the second assembly groove 25 to prevent the electrolyte from penetrating and adhering to the second connecting part 51 and the gap between the second connecting part 51 and the second assembly groove 25, thus ensuring the stability of the electrolyte.

[0149] In this embodiment, the second tail heat insulation member 86 covers the second end face 523 of the second adapter portion 52 and part of the second inner side face 522 of the second adapter portion 52. The second tail heat insulation member 86 is used to better separate the cell body 310 and the second tab 330 and block the heat conduction of the second tab 330 to the cell body 310 through the second adapter portion 52.

[0150] In this embodiment, the second side heat insulation member 84 and the second end heat insulation member 85 partially overlap. The overlapping portion of the second side heat insulation member 84 and the second end heat insulation member 85 covers the second bend portion 53. It can be understood that the overlapping portion of the second side heat insulation member 84 and the second end heat insulation member 85 increases the thickness of the high-temperature adhesive and forms a thickened area, which completely covers the second inner arc surface 532 of the second bend portion 53.

[0151] In some other embodiments, the second side heat insulation member 84 may also cover a portion of the second inner surface 512 of the second connecting portion 51, and the second end heat insulation member 85 may also cover a portion of the second inner surface 522 of the second transition portion 52. Therefore, the overlapping portion of the second side heat insulation member 84 and the second end heat insulation member 85 covers not only the second bend portion 53, but also a portion of the second transition portion 52 and a portion of the second connecting portion 51. It can be understood that the thickened areas of the second side heat insulation member 84 and the second end heat insulation member 85 completely cover the second inner arc surface 532 of the second bend portion 53, a portion of the second inner surface 522 on both sides of the second inner arc surface 532, and a portion of the second inner surface 512.

[0152] In some other embodiments, the second end heat insulation member 85 may also cover a portion of the second inner surface 522 of the second transition portion 52. Therefore, the overlapping portion of the second side heat insulation member 84 and the second end heat insulation member 85, in addition to covering the second bend portion 53, may also cover a portion of the second transition portion 52. It can be understood that the thickened areas of the second side heat insulation member 84 and the second end heat insulation member 85 completely cover the second inner arc surface 532 of the second bend portion 53 and a portion of the second inner surface 522 on one side of the second inner arc surface 532.

[0153] In some other embodiments, the second side heat insulation member 84 may also cover a portion of the second inner surface 512 of the second connecting portion 51. Therefore, the overlapping portion of the second side heat insulation member 84 and the second end heat insulation member 85, in addition to covering the second bend portion 53, may also cover a portion of the second connecting portion 51. It can be understood that the thickened areas of the second side heat insulation member 84 and the second end heat insulation member 85 completely cover the second inner arc surface 532 of the second bend portion 53 and a portion of the second inner surface 512 on the other side of the second inner arc surface 532.

[0154] In this embodiment, the second side heat insulation member 84 also partially overlaps with the second tail heat insulation member 86. The overlapping portion of the second side heat insulation member 84 and the second tail heat insulation member 86 covers the second inner surface 522 of the second transition portion 52. It can be understood that the overlapping portion of the second side heat insulation member 84 and the second tail heat insulation member 86 increases the thickness of the high-temperature adhesive and forms a thickened area, which completely covers the second inner surface 522 of the second transition portion 52.

[0155] In some other embodiments, the second side heat insulation member 84 may also cover a portion of the second end face 523 of the second transition portion 52, and the overlapping portion of the second side heat insulation member 84 and the second tail heat insulation member 86 may cover both the second inner side surface 522 and the second end face 523 of the second transition portion 52. It is understood that the thickened areas of the second side heat insulation member 84 and the second tail heat insulation member 86 completely cover the second inner side surface 522 and the second end face 523 of the second transition portion 52.

[0156] In some other embodiments, the second tail heat insulation member 86 only covers the second end face 523 of the second transition portion 52, and the second side heat insulation member 84 covers not only the second inner side face 522 of the second transition portion 52, but also a portion of the second end face 523 of the second transition portion 52. The overlapping portion of the second side heat insulation member 84 and the second tail heat insulation member 86 covers the second end face 523 of the second transition portion 52. It can be understood that the thickened areas of the second side heat insulation member 84 and the second tail heat insulation member 86 completely cover the second end face 523 of the second transition portion 52.

[0157] It should be noted that the second side heat insulation member 84, the second end heat insulation member 85, and the second tail heat insulation member 86 can be integrally formed, or they can be separately formed to adapt to different needs in actual production applications. In some embodiments, the heat insulation member 80 includes the second side heat insulation member 84 and the second end heat insulation member 85. The second side heat insulation member 84 and the second end heat insulation member 85 are integrally formed, or they are separately formed. One end of the second side heat insulation member 84 away from the second end heat insulation member 85 extends to the second end face 523 of the second transition portion 52, and the second side heat insulation member 84 covers the second inner side face 522 and at least part of the second end face 523. This application does not impose strict limitations on this.

[0158] It is understood that the thickened area of ​​the heat insulation member 80 covering the second pin 50 can completely cover the second inner arc surface 532 of the second bend 53. Alternatively, the thickened area of ​​the heat insulation member 80 covering the second pin 50 can completely cover the second inner arc surface 532 of the second bend 53, as well as a portion of the second inner side surface 522 and a portion of the second inner surface 512 connecting both sides of the second inner arc surface 532. Alternatively, the thickened area of ​​the heat insulation member 80 covering the second pin 50 can completely cover the second inner arc surface 532 of the second bend 53, as well as a portion of the second inner side surface 522 connecting one side of the second inner arc surface 532. Alternatively, the thickened area of ​​the heat insulation member 80 covering the second pin 50 can completely cover the second inner arc surface 532 of the second bend 53, as well as a portion of the second inner surface 512 connecting one side of the second inner arc surface 532.

[0159] Please refer to the following: Figure 3 , Figure 9 and Figure 10 , Figure 10 for Figure 2 The diagram shows a cross-sectional view of the energy storage device.

[0160] In this embodiment, the first pole post 60, the second pole post 70, the first pin 40, the second pin 50, the first lower plastic 10, the second lower plastic 20, and a plurality of heat insulation components 80 are mounted together on the end cover 30 to form the end cover assembly 100.

[0161] Specifically, along the Y-axis, the first lower plastic 10 is located at the end of the second lower plastic 20 away from the second boss 23, and the end of the first lower plastic 10 away from the first boss 13 is connected to the end of the second lower plastic 20 away from the second boss 23. The first top surface 111 of the first lower plastic 10 and the second top surface 211 of the second lower plastic 20 have the same orientation and are both connected to the lower surface 32 of the end cap 30.

[0162] The first through hole 17 of the first lower plastic 10 is coaxially arranged with the first electrode through hole 33 of the end cap 30. That is, the first through hole 413 of the first pin 40 is coaxially arranged with the first electrode through hole 33. The first electrode 60 passes through the first electrode through hole 33, the first through hole 17, and the first through hole 413 in sequence. The periphery of the first electrode 60 abuts against the hole wall of the first through hole 413. The first electrode 60 is fixed to the first connecting part 41 by laser welding to achieve electrical conduction between the first electrode 60 and the first pin 40. The first electrode 60 and the end cap 30 are insulated and sealed by a sealing element (not shown in the figure), which not only prevents short circuit between the first electrode 60 and the end cap 30, but also prevents the electrolyte inside the energy storage device 1000 from flowing out of the energy storage device 1000.

[0163] It should be noted that the smooth surface of the first end heat insulation member 82 can refract the laser energy generated when the first connecting part 41 and the first pole post 60 are laser welded, so as to avoid the laser energy affecting the performance of the first end heat insulation member 82.

[0164] The second through hole 27 of the second lower plastic 20 is coaxially arranged with the second electrode through hole 34 of the end cap 30. That is, the second through hole 513 of the second pin 50 is coaxially arranged with the second electrode through hole 34. The second electrode 70 passes through the second electrode through hole 34, the second through hole 27, and the second through hole 513 in sequence. The periphery of the second electrode 70 abuts against the hole wall of the second through hole 513. The second electrode 70 is fixed to the second connecting part 51 by laser welding to achieve electrical conduction between the second electrode 70 and the second pin 50. The second electrode 70 is insulated and sealed from the end cap 30 by a sealing element (not shown in the figure), which not only prevents short circuit between the second electrode 70 and the end cap 30, but also prevents the electrolyte inside the energy storage device 1000 from flowing out of the energy storage device 1000.

[0165] It should be noted that the smooth surface of the second end heat insulation member 85 can refract the laser energy generated when the second connecting part 51 and the second pole post 70 are laser welded, so as to avoid the laser energy affecting the performance of the second end heat insulation member 85.

[0166] In this embodiment, the length of the first lower plastic 10 is greater than the length of the second lower plastic 20. The width of the first lower plastic 10 is equal to the width of the second lower plastic 20. The sum of the lengths of the first lower plastic 10 and the second lower plastic 20 is less than or equal to the length of the lower plastic.

[0167] It can be explained that the first body 11 of the first lower plastic 10 and the second body 21 of the second lower plastic 20 are connected to form the body of the lower plastic. The first top surface 111 of the first lower plastic 10 and the second top surface 211 of the second lower plastic 20 form the top surface of the lower plastic. The first bottom surface 112 of the first lower plastic 10 and the second bottom surface 212 of the second lower plastic 20 form the bottom surface of the lower plastic.

[0168] The end cap assembly 100 is assembled with the battery cell 300. The bottom surface of the lower plastic faces the top surface 313 of the battery cell 300. The first protrusion 16 and the second protrusion 26 both abut against the top surface 313 of the battery cell body 310. The first pin 40 and the second pin 50 are located on opposite sides of the length of the battery cell body 310. The first pin 40 is connected to the first tab 320 by welding. The first side heat insulation member 81, the first end heat insulation member 82, and the first tail heat insulation member 83 are located between the first pin 40 and part of the first lower plastic 10 and the battery cell body 310, preventing the first pin 40 and the battery cell body 310 from contacting and short-circuiting, and preventing short circuits caused by metal debris adhering to the first pin 40 and the battery cell body 310 during component welding. They also prevent the high temperature generated when the first pin 40 is overcurrent from affecting the chemical stability of the electrolyte near the battery cell body 310 and the first pin 40, thereby preventing defects in the battery cell body 310 and improving the yield of the energy storage device 1000. Meanwhile, the second pin 50 is connected to the second tab 330 by welding. The second side heat insulation member 84, the second end heat insulation member 85, and the second tail heat insulation member 86 are located between the second pin 50 and part of the second lower plastic 20 and the cell body 310, preventing the second pin 50 and the cell body 310 from contacting and short-circuiting, and preventing short circuits caused by metal debris adhering to the second pin 50 and the cell body 310 during component welding. They also prevent the high temperature generated when the second pin 50 is overcurrent from affecting the chemical stability of the electrolyte near the cell body 310 and the second pin 50, thereby preventing defects in the cell body 310 and improving the yield of the energy storage device 1000.

[0169] Specifically, the first adapter 42 is connected to the first tab 320. The first tab 320 extends from the first side 311 of the cell body 310 to the side of the first adapter 42 facing away from the cell body 310, and is soldered to the first outer side 421 of the first adapter 42 to achieve electrical connection between the first tab 320 and the first pin 40. Furthermore, the first adapter 42 is separated from the cell body 310 by the first side heat insulation member 81 and the first tail heat insulation member 83. It is understandable that a large amount of heat is easily generated when the first tab 320 and the first adapter 42 are welded, and a large amount of heat is also generated when the first tab 320 and the first pin 40 are in the process of overcurrent. This heat will be blocked by the first side heat insulation member 81 and the first tail heat insulation member 83 and will not be transferred to the cell body 310 through the first pin 40. This avoids defects such as thermal shrinkage, melting and damage of the separator between the positive and negative electrode plates in the cell body 310, protects the separator, positive electrode plate and negative electrode plate of the cell body 310, and improves the yield of the energy storage device 1000.

[0170] The first bend 43 corresponds to the edge (not shown) of the cell body 310, which is the intersection of the top surface 313 and the first side surface 311 of the cell body 310. The first bend 43 is separated from the cell body 310 by the overlapping portion of the first side heat insulation member 81 and the first end heat insulation member 82. Since the first bend 43 is formed by bending, its current carrying capacity decreases after bending and stretching. Therefore, when the first pin 40 is overcurrent, the heat at the first bend 43 is also greater than that at the first connecting part 41 and the first transition part 42. Meanwhile, during the process of the electrolyte soaking the first pin 40, due to the insufficient adhesion of the single heat insulation component 80 to the first bending portion 43, the heat insulation component 80 located at the first bending portion 43 is prone to losing its adhesiveness when impacted by the electrolyte. This allows the electrolyte to penetrate into the space between the first pin 40, the first lower plastic 10, and the heat insulation component 80. When too much electrolyte accumulates between the first pin 40, the first lower plastic 10, and the heat insulation component 80, it can easily cause problems such as the initial adhesion of the heat insulation component 80 to the first pin 40 being loose and the secondary adhesion being insufficient. Therefore, an overlapping portion of the first side heat insulation member 81 and the first end heat insulation member 82 is provided at the first bend 43. The first side heat insulation member 81 and the first end heat insulation member 82 not only create mutual tension, increasing the adhesion of the heat insulation member 80 to the first bend 43, but also increase the thickness of the heat insulation member 80 covering the first bend 43. This better blocks heat conduction at the first bend 43 and is more conducive to blocking heat at the first bend 43 when the first pin 40 experiences overcurrent. It should be noted that the larger the overlapping area of ​​the first side heat insulation member 81 and the first end heat insulation member 82, the greater the mutual tension between them, and the greater the adhesion of the heat insulation member 80 to the first bend 43.

[0171] The first connecting portion 41 is separated from the cell body 310 by the first end heat insulation member 82. Since the heat generated during the welding of the first adapter portion 42 and the first tab 320 is transferred to the first connecting portion 41 via the first adapter portion 42 and the first bending portion 43, the first end heat insulation member 82 can prevent the heat transferred to the first connecting portion 41 from further being transferred to the cell body 310, further protecting the separator and electrode of the cell body 310. This avoids defects such as thermal shrinkage, melting, and damage to the separator between the positive and negative electrode plates in the cell body 310, improving the yield rate of the energy storage device 1000. Simultaneously, the first end heat insulation member 82 covers the first electrode post 60 passing through the first perforation 413 to prevent metal debris generated during the welding of the first electrode post 60 and the first connecting portion 41 from falling into the cell 300, preventing short circuits caused by contact between metal debris and the cell 300.

[0172] In some embodiments, when the first lower plastic 10 abuts against the cell body 310, and the first end heat insulation member 82 directly covers the first protrusion surface 161 and the first boss surface 131 of the first boss 13, the first end heat insulation member 82 not only separates the first lower plastic 10 from the cell body 310 to maximize the blocking of heat conduction from the first pin 40 and the first lower plastic 10 near the first pin 40 towards the cell body 300, thus avoiding the impact of high temperature on the cell 300, but also the smooth surface of the first end heat insulation member 82 can prevent the first lower plastic 10 from rubbing against the cell body 310 during contact, thereby improving the yield of the energy storage device 1000.

[0173] The second adapter 52 is connected to the second tab 330. The second tab 330 extends from the second side 312 of the cell body 310 to the side of the second adapter 52 facing away from the cell body 310, and is soldered to the second outer side 521 of the second adapter 52 to achieve electrical connection between the second tab 330 and the second pin 50. Furthermore, the second adapter 52 is separated from the cell body 310 by the second side heat insulation member 84 and the second tail heat insulation member 86. It is understandable that a large amount of heat is easily generated when the second tab 330 and the second adapter 52 are welded together, and a large amount of heat is also generated when the second tab 330 and the second pin 50 are in overcurrent condition. This heat is blocked by the second side heat insulation member 84 and the second tail heat insulation member 86 and cannot be transferred to the cell body 310 through the second pin 50. This avoids defects such as thermal shrinkage, melting and damage of the separator between the positive and negative electrodes in the cell body 310, protects the separator, positive electrode and negative electrode of the cell body 310, and improves the yield of the energy storage device 1000.

[0174] The second bend 53 corresponds to the edge (not shown) of the cell body 310, which is the intersection of the top surface 313 and the second side surface 312 of the cell body 310. The second bend 53 is separated from the cell body 310 by the overlapping portion of the second side heat insulation member 84 and the second end heat insulation member 85. Since the second bend 53 is formed by bending, its current carrying capacity decreases after bending and stretching. Therefore, when the second pin 50 is overcurrent, the heat at the second bend 53 is also greater than that at the second connecting part 51 and the second transition part 52. Meanwhile, during the process of the electrolyte wetting the second pin 50, due to the insufficient adhesion of the single heat insulation component 80 to the second bend 53, the heat insulation component 80 at the second bend 53 is prone to lose its adhesiveness when impacted by the electrolyte. This allows the electrolyte to penetrate into the space between the second pin 50, the second lower plastic 20, and the heat insulation component 80. When too much electrolyte accumulates between the second pin 50, the second lower plastic 20, and the heat insulation component 80, it can easily cause problems such as poor initial adhesion between the heat insulation component 80 and the second pin 50, as well as insufficient adhesion during the second adhesion. Therefore, an overlapping portion of the second side heat insulation member 84 and the second end heat insulation member 85 is provided in the second bend portion 53. The second side heat insulation member 84 and the second end heat insulation member 85 not only form a mutual pull, increasing the adhesion of the heat insulation member 80 to the second bend portion 53, but the overlapping portion also increases the thickness of the heat insulation member 80 covering the second bend portion 53, which can better block the heat conduction of the second bend portion 53, and is more conducive to blocking the heat at the second bend portion 53 when the second pin 50 is overcurrent. It should be noted that the larger the area of ​​the overlapping portion of the second side heat insulation member 84 and the second end heat insulation member 85, the greater the mutual pulling force between the second side heat insulation member 84 and the second end heat insulation member 85, and the greater the adhesion of the heat insulation member 80 to the second bend portion 53.

[0175] The second connection portion 51 is separated from the cell body 310 by the second end heat insulation member 85. Since the heat generated during the welding of the second adapter portion 52 and the second tab 330 is transferred to the second connection portion 51 via the second adapter portion 52 and the second bending portion 53, the second end heat insulation member 85 can prevent the heat transferred to the second connection portion 51 from further transferring to the cell body 310, further protecting the separator and electrode of the cell body 310. This avoids defects such as thermal shrinkage, melting, and damage to the separator between the positive and negative electrode plates in the cell body 310, improving the yield rate of the energy storage device 1000. Simultaneously, the second end heat insulation member 85 covers the second pole post 70 that passes through the second perforation 513, preventing metal debris generated during the welding of the second pole post 70 and the second connection portion 51 from falling into the cell 300, thus preventing short circuits caused by contact between metal debris and the cell 300.

[0176] In some embodiments, when the second lower plastic 20 abuts against the cell body 310, and the second end heat insulation member 85 directly covers the second protrusion surface 261 and the second protrusion surface 231 of the second protrusion 23, the second end heat insulation member 85 not only separates the second lower plastic 20 from the cell body 310 to maximize the blocking of heat conduction from the second pin 50 and the second lower plastic 20 near the second pin 50 towards the cell body 300, thus avoiding the impact of high temperature on the cell 300, but also the smooth surface of the second end heat insulation member 85 can prevent the second lower plastic 20 from rubbing against the cell body 310 during contact, thereby improving the yield of the energy storage device 1000.

[0177] It should be noted that the length of the first adapter 42 (i.e., the dimension along the Z-axis) is less than the length of the first tab 320 (i.e., the dimension along the Z-axis). The length of the second adapter 52 (i.e., the dimension along the Z-axis) is less than the length of the second tab 330 (i.e., the dimension along the Z-axis).

[0178] Both the end cap assembly 100 and the battery cell 300 are installed inside the housing 200. The edge of the end cap 30 is connected to the edge of the opening 201 of the housing 200 by welding or other means to seal the energy storage device 1000.

[0179] In related technologies, when the cell body 310 adopts a laminated design, the tabs are led out from the cell body 310, bent, and then soldered to the leads. However, the soldering of the tabs to the leads easily generates high temperatures, which are transferred to the cell body 310 through the leads, causing a series of defects in the cell body 310, such as thermal shrinkage, melting, and damage to the separator between the positive and negative electrodes, thus reducing the yield of the energy storage device 1000.

[0180] In this embodiment, a first side heat insulation member 81, a first end heat insulation member 82, and a first tail heat insulation member 83 are provided on the first lower plastic 10 near the first pin 40 to reduce the impact of the large amount of heat generated during the welding of the first pin 40, the first tab 320, and the first terminal 60 on the cell body 310 by means of physical barriers. That is, it avoids defects such as thermal shrinkage, melting, and damage to the separator between the positive and negative electrodes. In addition, the first side heat insulation member 81, the first end heat insulation member 82, and the first tail heat insulation member 83 also prevent short circuits caused by the contact between the first pin 40 and the cell body 310, and prevent short circuits caused by metal debris generated during the welding of the first pin 40 with the first terminal 60 and the first tab 320 falling into the first pin 40 and the cell body 310.

[0181] Meanwhile, a second side heat insulation member 84, a second end heat insulation member 85, and a second tail heat insulation member 86 are also provided on the second lower plastic 20 near the second pin 50 to reduce the impact of the large amount of heat generated during the welding of the second pin 50, the second tab 330, and the second terminal 70 on the cell body 310. In addition, the second side heat insulation member 84, the second end heat insulation member 85, and the second tail heat insulation member 86 also prevent short circuits caused by the contact between the second pin 50 and the cell body 310, and prevent short circuits caused by metal debris generated during the welding of the second pin 50 with the second terminal 70 and the second tab 330 falling into the second pin 50 and the cell body 310, thereby improving the yield of the energy storage device 1000.

[0182] Because thermal conductivity is better between metals and poorer between metals and plastics, thickened areas are provided between the first pin 40 and the cell body 310, and between the second pin 50 and the cell body 310. These thickened areas better block heat conduction from the first pin 40 and the second pin 50 to the cell body 310, which is more conducive to preventing heat from the first pin 40 and the second pin 50 during overcurrent. This reduces the probability of abnormalities in the cell 300 (such as increased internal resistance, self-discharge, and fire) to a certain extent, and ensures temperature consistency between the first pin 40 and the second pin 50, thus improving the overall service life of the energy storage device 1000. The heat insulation component 80 also blocks heat conduction, reducing the risk of lithium metal deposition at the negative electrode and ensuring the safety of the energy storage device 1000. Meanwhile, as the area of ​​the thickened region increases, the mutual pulling force between two adjacent heat insulation components 80 increases, and the adhesion of the heat insulation component 80 to the first pin 40 and the second pin 50 increases, which is beneficial to improving the yield of the energy storage device 1000.

[0183] The above are merely some embodiments and implementation methods of this application. 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. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An end cap assembly, characterized in that, include: The lower plastic includes a body, the body includes a top surface and a bottom surface, the top surface and the bottom surface are arranged opposite to each other along the thickness direction of the body, the lower plastic also includes an assembly groove, the assembly groove includes a groove bottom surface, the groove bottom surface and the bottom surface have the same orientation; The pin includes a connecting portion, an adapter portion, and a bent portion connecting the connecting portion and the adapter portion. The extending direction of the connecting portion and the extending direction of the adapter portion form an angle. The connecting portion is accommodated in the assembly groove, and the adapter portion extends away from the lower plastic. The connecting part includes an outer surface and an inner surface, the inner surface and the outer surface are arranged opposite to each other along the thickness direction of the connecting part, the outer surface is connected to the bottom surface of the groove, and the inner surface faces away from the bottom surface of the groove. The transition part includes an inner side surface, and the bending part includes an inner arc surface, the inner arc surface connects the inner surface and the inner side surface. and A heat insulation element is stacked on the pin and completely covers the inner surface and the inner side surface. The heat insulation element includes a thickened area that completely covers the inner arc surface.

2. The end cap assembly according to claim 1, characterized in that, The thickened area covers a portion of the inner side surface and / or a portion of the inner surface that connects the two sides of the inner arc surface.

3. The end cap assembly according to claim 1, characterized in that, The ratio of the area of ​​the thickened region to the area of ​​the inner arc surface is greater than or equal to 1.2 and less than or equal to 5.

4. The end cap assembly according to claim 1, characterized in that, The heat insulation component includes an end heat insulation component and a side heat insulation component, the side heat insulation component covers the inner side surface and the inner arc surface, and the end heat insulation component covers the inner arc surface and the inner surface; The end heat insulation component and the side heat insulation component partially overlap, and the overlapping portion of the end heat insulation component and the side heat insulation component is the thickened area.

5. The end cap assembly according to claim 4, characterized in that, The bottom surface is provided with a boss, the boss including a boss surface facing away from the bottom surface; the assembly groove is recessed in the boss surface and located at the end of the lower plastic in the length direction; The end heat insulation completely covers the boss surface, or the end heat insulation completely covers the boss surface and the bottom surface of the lower plastic on the side of the boss facing away from the mounting groove.

6. The end cap assembly according to claim 4, characterized in that, The bottom surface is provided with a boss, the boss including a boss surface facing away from the bottom surface; the assembly groove is recessed in the boss surface and located at the end of the lower plastic in the length direction; Along the width direction of the lower plastic, the width of the end heat insulation member is greater than the width of the pin, and the width of the end heat insulation member exceeding the width of the pin is called the excess width. The ratio of the width of the thickened area to the excess width is greater than or equal to 1.1 and less than or equal to 3.

7. The end cap assembly according to claim 4, characterized in that, The side insulation also covers a portion of the inner surface, and the end insulation also covers a portion of the inner side surface. The overlapping portion of the end insulation and the side insulation covers a portion of the inner side surface and a portion of the inner surface.

8. The end cap assembly according to claim 4, characterized in that, The end heat insulation component and the side heat insulation component are integrally formed, or the end heat insulation component and the side heat insulation component are separately formed.

9. The end cap assembly according to claim 5, characterized in that, The bottom surface is also provided with a protrusion. The protrusion and the boss are arranged adjacent to each other along the length direction of the lower plastic. The protrusion protrudes from the bottom surface of the boss. The protrusion includes an inner side surface. The inner side surface of the protrusion faces the boss and is connected to the boss surface. The edge of the end heat insulation member abuts against the inner side surface of the protrusion.

10. The end cap assembly according to claim 6, characterized in that, The bottom surface is further provided with a protrusion, the protrusion and the boss are arranged adjacent to each other along the length direction of the lower plastic, the protrusion includes a protruding surface, the protruding surface faces away from the bottom surface, the end heat insulation member covers the boss surface and the protruding surface, or the end heat insulation member covers the outer side of the protrusion facing away from the boss; and / or, the end heat insulation member covers a portion of the bottom surface of the lower plastic located on the side of the protrusion facing away from the boss.

11. The end cap assembly according to any one of claims 1-7, characterized in that, The pin includes a first pin and a second pin, which are located at opposite ends of the lower plastic along its length. The first pin is the positive pin, and the second pin is the negative pin. The end heat insulation component includes a first end heat insulation component and a second end heat insulation component, and the side heat insulation component includes a first side heat insulation component and a second side heat insulation component. The first end heat insulation component and the first side heat insulation component cover the first pin, and the second end heat insulation component and the second side heat insulation component cover the second pin.

12. The end cap assembly according to claim 1, characterized in that, The end cap assembly further includes an electrode post and an end cap. The end cap and the lower plastic are stacked along the thickness direction of the end cap assembly. The end cap includes an electrode post through hole that penetrates both surfaces of the end cap in the thickness direction. The connecting part includes a through hole that penetrates the inner surface and the outer surface. The lower plastic also includes a through hole that penetrates the bottom surface and the top surface of the groove. The electrode post through hole, the through hole, and the through hole are coaxially arranged. The electrode post passes through the electrode post through hole, the through hole, and the through hole, and is electrically connected to the connecting part. The heat insulation element covers the pole.

13. 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 1-12, wherein the housing includes an opening, the battery cell is mounted in the housing, the battery cell includes a cell body and a tab, the cell body includes a side surface and a top surface connected to the side surface, the tab extends from the side surface and is electrically connected to the cell body, the end cap assembly seals the opening, the bottom surface faces the top surface, the adapter is stacked with the tab and electrically connected to the tab, and the heat insulation member has its side facing away from the pin facing the cell body.

14. An electrical appliance, characterized in that, It includes the energy storage device as described in claim 13, wherein the energy storage device supplies power to the electrical equipment.

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