Lower plastic, end cap assembly, energy storage device and energy storage system

Abstract

The present disclosure provides a lower plastic, an end cover assembly, an energy storage device and an energy storage system, and relates to the technical field of energy storage. The lower plastic comprises a lower plastic body, a first boss, a second boss, a first raised edge and a second raised edge. The first boss and the second boss are located on the second surface of the lower plastic body, and the first boss is arranged close to the first end and the second boss is arranged close to the second end. The first raised edge and the second raised edge are located on the second surface of the lower plastic body, and the first raised edge is arranged on the first side edge and the second raised edge is arranged on the second side edge. In the second direction, the height of the first boss is greater than or equal to twice the height of the first raised edge and twice the height of the second raised edge, and the height of the second boss is greater than or equal to twice the height of the first raised edge and twice the height of the second raised edge. In the third direction, the width of the first boss and the width of the second boss are both less than or equal to the distance between the first raised edge and the second raised edge. The lower plastic provided by the present disclosure can improve the flatness of the lower plastic.

Description

Technical Field

[0001] This disclosure relates to the field of energy storage technology, and more specifically, to a lower plastic, an end cap assembly, an energy storage device, and an energy storage system. Background Technology

[0002] Secondary batteries, also known as rechargeable batteries or storage batteries, are batteries that can be recharged after being discharged, allowing the active materials to be reactivated and reused. The recyclable nature of secondary batteries has made them a primary power source for electrical equipment.

[0003] As the demand for rechargeable batteries gradually increases, people have higher requirements for their capacity, so the length of rechargeable batteries is getting longer and longer. However, the length of the lower plastic part in the rechargeable battery is also getting longer, which makes the lower plastic part prone to bending and deformation after injection molding.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0005] The purpose of this disclosure is to provide a lower plastic, an end cap assembly, an energy storage device, and an energy storage system that can improve the flatness of the lower plastic.

[0006] According to one aspect of this disclosure, a lower plastic material is provided for an energy storage device, the lower plastic material comprising: The lower plastic body has a first end and a second end along a first direction, a first surface and a second surface along a second direction, and a first side and a second side along a third direction; the first direction, the second direction and the third direction intersect each other; A first protrusion and a second protrusion are located on the second surface of the lower plastic body, with the first protrusion disposed near the first end and the second protrusion disposed near the second end. A first protruding edge and a second protruding edge are located on the second surface of the lower plastic body and protrude in a direction perpendicular to the second surface; the first protruding edge is provided on the first side and the second protruding edge is provided on the second side. In the second direction, the height of the first boss is greater than or equal to twice the height of the first protrusion and twice the height of the second protrusion, and the height of the second boss is greater than or equal to twice the height of the first protrusion and twice the height of the second protrusion; in the third direction, the width of the first boss and the width of the second boss are both less than or equal to the distance between the first protrusion and the second protrusion.

[0007] In one exemplary embodiment of this disclosure, in the second direction, the height of the first convex edge and / or the second convex edge is greater than or equal to 3 mm.

[0008] In one exemplary embodiment of this disclosure, in the third direction, the thickness of the first convex edge is greater than or equal to half the height of the first side platform, and / or the thickness of the second convex edge is greater than or equal to half the height of the second side platform.

[0009] In an exemplary embodiment of this disclosure, the first end of the lower plastic body is provided with a first pole post connection hole, and the second end is provided with a second pole post connection hole; the first boss is located on the side of the first pole post connection hole close to the second pole post connection hole, and the second boss is located on the side of the second pole post connection hole close to the first pole post connection hole.

[0010] In one exemplary embodiment of this disclosure, at least one first positioning post is provided on the second surface of the first end of the lower plastic body. The first positioning post is disposed near the first pole post connection hole, and the first positioning post and the first pole post connection hole are located on the same side of the first boss along the first direction; and / or, At least one second positioning post is provided on the second surface of the second end of the lower plastic body. The second positioning post is located near the second pole post connection hole, and the second positioning post and the second pole post connection hole are located on the same side of the second boss along the first direction.

[0011] In one exemplary embodiment of this disclosure, at least two first positioning baffles are provided on the second surface of the first end of the lower plastic body, and the at least two first positioning baffles are disposed opposite to each other along the third direction; in the third direction, a first reinforcing plate is provided on the side of the first positioning baffle facing away from the second positioning baffle; and / or, At least two second positioning baffles are provided on the second surface of the second end of the lower plastic body, and the at least two second positioning baffles are arranged opposite to each other along the third direction; in the third direction, a second reinforcing plate is provided on the side of the second positioning baffle away from the first positioning baffle.

[0012] In one exemplary embodiment of this disclosure, along the first direction, the first positioning post and the first positioning baffle are located on opposite sides of the first pole post connecting hole, and the first positioning baffle is located on the side of the first positioning post away from the first boss; and / or, Along the first direction, the second positioning post and the second positioning baffle are located on both sides of the second pole post connecting hole, and the second positioning baffle is located on the side of the second positioning post away from the second boss.

[0013] In one exemplary embodiment of this disclosure, a first support structure is provided on the second surface of the first end of the lower plastic body, the first support structure being located along the first direction on the side of the first pole post connection hole away from the first boss; and / or, a second support structure is provided on the second surface of the second end of the lower plastic body, the second support structure being located along the first direction on the side of the second pole post connection hole away from the second boss.

[0014] In one exemplary embodiment of this disclosure, the first support structure has a first support surface facing the first boss, and the angle between the first support surface and the second surface is an obtuse angle; and / or, the second support structure has a second support surface facing the second boss, and the angle between the second support surface and the second surface is an obtuse angle.

[0015] In one exemplary embodiment of this disclosure, the lower plastic body includes a first body portion and a second body portion separately disposed along the first direction, wherein the length of the first body portion is greater than the length of the second body portion in the first direction; the first boss is located on the first body portion, and the second boss is located on the second body portion.

[0016] In one exemplary embodiment of this disclosure, the lower plastic further includes: An explosion-proof mesh is disposed on the first body portion and located at an end away from the first protrusion along the first direction; in the second direction, the height of the explosion-proof mesh is equal to the height of the first protrusion; in the third direction, the width of the explosion-proof mesh is less than or equal to the distance between the first protruding edge and the second protruding edge.

[0017] In one exemplary embodiment of this disclosure, a clearance groove matching the shape of the explosion-proof valve is provided at a position on the first surface of the first body corresponding to the explosion-proof mesh.

[0018] In one exemplary embodiment of this disclosure, in the first direction, the distance between the side of the explosion-proof mesh away from the first protrusion and the end of the first body portion away from the first protrusion is greater than the distance between the side of the first protrusion close to the explosion-proof mesh and the end of the first body portion away from the explosion-proof mesh.

[0019] According to another aspect of this disclosure, an end cap assembly is provided, the end cap assembly including the aforementioned lower plastic.

[0020] According to another aspect of this disclosure, an energy storage device is provided, the energy storage device comprising: A housing having an opening for receiving space; An electrode assembly disposed in the receiving space; The aforementioned end cap assembly covers the opening.

[0021] According to another aspect of this disclosure, an energy storage system is provided, which includes the energy storage device described above.

[0022] The lower plastic body disclosed herein has a first protrusion and a second protrusion at both ends. The width of the first protrusion and the width of the second protrusion are both less than or equal to the distance between the first protruding edge and the second protruding edge. Therefore, when the second surfaces of the two lower plastic bodies are fastened together, the first protrusion and the second protrusion on the upper lower plastic body can extend into the space between the first protruding edge and the second protruding edge on the lower lower plastic body, and the first protrusion and the second protrusion on the lower lower plastic body can extend into the space between the first protruding edge and the second protruding edge on the upper lower plastic body. Simultaneously, since the height of the first protrusion and the height of the second protrusion are both greater than or equal to twice the height of the first protruding edge and twice the height of the second protruding edge, when the two lower plastic bodies are fastened together, the first protruding edge on the upper lower plastic body and the corresponding protruding edge on the lower lower plastic body... There can be a gap between the first protruding edges on the lower plastic, and there can be a gap between the second protruding edge on the upper lower plastic and the corresponding second protruding edge on the lower lower plastic. At this time, by applying an external force to the two lower plastics that are fastened together in the second direction, the first protruding edge on the upper lower plastic and the first protruding edge on the corresponding lower lower plastic can be brought closer and abutted together, and the second protruding edge on the upper lower plastic and the second protruding edge on the corresponding lower lower plastic can be brought closer and abutted together. After a long period of straightening, the two lower plastics that are fastened together can release the stored internal stress, thereby overcoming the bending phenomenon caused by the injection molding internal stress of the lower plastic, improving the flatness of the lower plastic, and thus improving the process yield and assembly stability of the lower plastic.

[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0025] Figure 1 This is a schematic diagram of an energy storage system provided in one embodiment of the present disclosure.

[0026] Figure 2 This is a schematic diagram of a battery pack provided according to one embodiment of the present disclosure.

[0027] Figure 3 An exploded view of a battery pack provided for one embodiment of this disclosure.

[0028] Figure 4 This is a schematic diagram of an end cap assembly provided in one embodiment of the present disclosure.

[0029] Figure 5 This is a schematic diagram of removing the light aluminum sheet from an end cap assembly provided in one embodiment of the present disclosure.

[0030] Figure 6 This is a schematic diagram of an end cap assembly provided in one embodiment of the present disclosure from another perspective.

[0031] Figure 7 This is a schematic diagram of an end cap provided according to one embodiment of the present disclosure.

[0032] Figure 8 This is a schematic diagram of the other side of the end cap provided in one embodiment of the present disclosure.

[0033] Figure 9 This is a schematic diagram showing two lower plastic fasteners fastened together, according to one embodiment of the present disclosure.

[0034] Figure 10 This is a schematic diagram of the other side of two lower plastic fasteners fastened together, according to one embodiment of the present disclosure.

[0035] Figure 11 A side view showing two lower plastic fasteners fastened together, according to one embodiment of this disclosure.

[0036] Figure 12 This is a top view of two lower plastic fasteners fastened together, according to one embodiment of the present disclosure.

[0037] Figure 13 for Figure 12 Cross-sectional view of the EE surface.

[0038] Figure 14 for Figure 8 A magnified view of a portion of point A in the middle.

[0039] Figure 15 for Figure 8 A magnified view of a section at point B in the middle.

[0040] Figure 16 for Figure 6 A magnified view of a section at point C.

[0041] Figure 17 for Figure 6 A magnified view of a section at point D.

[0042] Explanation of reference numerals in the attached figures: 10. Energy storage device; 20. High-voltage cable; 30. First power conversion device; 40. Second power conversion device; 50. Battery pack; 510. Battery housing; 511. Lower housing; 512. Housing cover; 520. Battery module; 530. Individual battery cell; 100. End cap assembly; 110. Lower plastic; 1110. Lower plastic body; 1111. First body portion; 1112. Second body portion; 1121. First end; 1122. Second end; 1123. First surface; 1124. Second surface; 1125. First side; 1126. Second side; 1131. First boss; 1132. Second boss; 1141. First protruding edge; 1142. Second protruding edge; 1151. First pole post connection hole; 1152. Second... 1161. First positioning post; 1162. Second positioning post; 1171. First positioning baffle; 1172. Second positioning baffle; 1173. First reinforcing plate; 1174. Second reinforcing plate; 1180. Second support structure; 1181. Second support surface; 1190. Explosion-proof mesh; 1191. Clearance groove; 120. Plain aluminum sheet; 130. Explosion-proof valve; 141. First pole post; 142. Second pole post; 151. First adapter; 152. Second adapter; X, first direction; Z, second direction; Y, third direction. Detailed Implementation

[0043] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0044] Because the energy people need is highly time- and space-dependent, in order to make rational use of energy and improve energy efficiency, it is necessary to use a medium or device to store one form of energy in the same way or by converting it into another form of energy, and then release it in a specific form of energy based on future application needs.

[0045] Currently, the generation of green electricity generally relies on solar, wind, and hydropower. However, wind and solar power are generally characterized by strong intermittency and large fluctuations, which can cause grid instability, insufficient power during peak demand periods, and excessive power 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. This involves converting electrical energy into other forms of energy through physical or chemical means and storing it. When needed, this energy can be converted back into electrical energy and released. Simply put, energy storage is like a large "power bank," storing electrical energy when solar and wind power are abundant and releasing the stored electricity when needed.

[0046] Taking electrochemical energy storage as an example, this solution provides an energy storage device for use in energy storage systems. The energy storage device is equipped with a set of chemical batteries, which mainly use the chemical elements in the batteries as energy storage media. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage media. 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 electricity is released for use, or transferred to places with a shortage of electricity for use.

[0047] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, and consumption-side energy storage. The corresponding types of energy storage devices include: Large-scale energy storage power stations applied to wind and solar power plants can assist renewable energy generation in meeting grid connection requirements and improve the utilization rate of renewable energy. As a high-quality active / reactive power source on the power supply side, energy storage power stations can achieve load matching of electricity in time and space, enhance the absorption capacity of renewable energy, reduce instantaneous power fluctuations, reduce the impact on the power grid, improve the absorption of new energy generation, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation. Energy storage containers used on the grid side mainly function as peak shaving, frequency regulation, and grid congestion relief. In terms of peak shaving, they can achieve peak shaving and valley filling of electricity load, that is, charging the energy storage battery when the electricity load is low and releasing the stored electricity during the peak electricity load period, thereby achieving a balance between power production and consumption. Small-scale energy storage cabinets applied to the electricity consumption side primarily function to facilitate self-consumption of electricity, peak-valley price arbitrage, capacity cost management, and improve power supply reliability. Depending on the application scenario, electricity consumption-side energy storage can be categorized into commercial and industrial energy storage cabinets, residential energy storage devices, and energy storage charging piles, generally used in conjunction with distributed photovoltaic (PV) systems. Commercial and industrial users can utilize energy storage for peak-valley price arbitrage and capacity cost management. In electricity markets implementing peak-valley pricing, charging the energy storage system during low electricity prices and discharging it during high electricity prices allows for arbitrage, reducing electricity costs. Furthermore, industrial enterprises subject to two-part tariffs can utilize energy storage systems to store energy during off-peak hours and discharge it during peak load periods, thereby reducing peak power and the maximum declared demand, ultimately lowering capacity costs. Residential PV systems combined with energy storage can improve self-consumption levels. High electricity prices and poor power supply stability drive demand for residential PV installations. Given that photovoltaic power generation occurs during the day, while user load is generally higher at night, configuring energy storage can better utilize photovoltaic power, improve self-consumption levels, and reduce electricity costs. Furthermore, energy storage is needed in areas such as communication base stations and data centers for backup power.

[0048] In some embodiments, such as Figure 1 As shown, the embodiments of this disclosure are illustrated using a shared energy storage scenario on the generation / distribution side as an example, but the energy storage device disclosed herein is not limited to such a scenario.

[0049] This disclosure provides an energy storage system, comprising: a high-voltage cable 20, a first power conversion device 30, a second power conversion device 40, and the energy storage device 10 provided in this disclosure. In some embodiments of the power generation scenario, the second power conversion device 40 can be a wind power conversion device. Since the electricity generated by wind power conversion is volatile, random, and intermittent, the unstable electricity output by the wind power conversion device can be stored in the energy storage device 10 through grid connection. The energy storage device 10 is connected to the high-voltage cable 20 and outputs smooth electricity to the power consumption side of the distribution network, achieving peak shaving and frequency regulation, and ensuring stable grid operation; or, the wind power conversion device is always connected to the high-voltage cable 20. High-voltage cable 20 connects the wind power conversion device to the power consumption side of the distribution network under normal power generation conditions. When the current power load is low and the wind power conversion device generates excess power, the excess power is first stored in energy storage device 10 to reduce wind and solar curtailment rates and improve the problem of new energy power generation consumption. When the power load is high, the power grid issues an instruction to transmit the power stored in energy storage device 10 together with high-voltage cable 20 in grid-connected mode to supply power to the power consumption side. This provides the power grid with various services such as peak shaving, frequency regulation, and backup, giving full play to the peak shaving role of the power grid, promoting peak shaving and valley filling, and alleviating the power supply pressure of the power grid.

[0050] In some embodiments on the distribution network side, the first power conversion device 30 can be a photovoltaic power conversion device. The energy storage device 10 is connected to the high-voltage cable 20 and installed downstream of the high-voltage cable 20 between the user load and the user load. The power output by the photovoltaic power conversion device is stored in the energy storage device 10, which can respond in a timely manner to act as a backup power source when the power grid / distribution network fails. Alternatively, it can provide power supply support to alleviate line congestion when the high-voltage cable 20 transmission line is blocked, and to delay the economic pressure caused by the expansion of the power grid / distribution capacity when the power grid is planned to be expanded.

[0051] Optionally, the first power conversion device 30 may include, but is not limited to, a photovoltaic power conversion device, and the second power conversion device 40 may include, but is not limited to, a wind power conversion device. The first power conversion device 30 and the second power conversion device 40 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy and mechanical energy into electrical energy.

[0052] Optionally, the energy storage device 10 may include, but is not limited to, energy storage applications such as energy storage power stations, hydropower / thermal / wind power generation systems, solar power generation systems, mobile power systems, smart home systems, or temporary power supply systems, and may also be applied in multiple fields such as data centers, military equipment, aerospace, charging piles, and electric vehicles.

[0053] In some embodiments, such as Figure 2 and Figure 3 As shown, taking the energy storage device 10 as an example of a battery pack 50, the battery pack 50 includes a battery housing 510 and multiple battery modules 520. The battery housing 510 includes a lower housing 511 and a housing cover 512, and the housing cover 512 is fixedly / detachably connected to the lower housing 511 to form a battery compartment. Multiple battery modules 520 are located inside the battery compartment.

[0054] The battery compartment of the battery housing 510 can hold at least one battery module 520, such as one, two, four, five, six, seven, eight, or more. The more battery modules 520 there are, the higher the capacity of the battery pack 50, thus making it easier to meet market demands. For example, such as... Figure 3 As shown, the battery compartment of the battery box 510 can accommodate a total of eight battery modules 520, which are arranged in two rows along the length of the battery box 510 and four columns along the width of the battery box 510.

[0055] Each battery module 520 may include a pair of end plates arranged opposite each other along the cell arrangement direction, and a plurality of individual cells 530 located between the pair of end plates. The plurality of individual cells 530 and the pair of end plates may be fixed by binding tools such as cable ties. The plurality of individual cells 530 are arranged along the length direction of the battery box 510, and the plurality of individual cells 530 are connected by cell connecting pieces to realize series / parallel electrical connection between the plurality of individual cells 530.

[0056] In this configuration, multiple individual cells 530 are connected in series, with each cell connector connected to the electrode terminals of different polarities on two individual cells 530 respectively; or, multiple individual cells 530 are connected in parallel in pairs and then connected in series between the groups, with each cell connector first connected to the electrode terminals of the same polarity on two individual cells 530 respectively, and then connected to the electrode terminals of opposite polarity on two other individual cells 530.

[0057] It is understood that the energy storage device 10 is not limited to the battery pack 50. The energy storage device 10 can be a single battery cell 530, or a battery module 520 composed of single batteries 530, a battery cluster, a power bank, an energy storage cabinet / energy storage container, or other battery integrated systems. The actual application form of the energy storage device 10 provided in this disclosure embodiment can be, but is not limited to, the listed products, and can also be other application forms. This application embodiment does not strictly limit the application form of the energy storage device 10.

[0058] The single-cell battery 530 can be a rechargeable battery, meaning it can be reused after being discharged by recharging to activate the active materials. The single-cell battery 530 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application does not specifically limit its type. Below, this disclosure uses a square-shaped single-cell battery 530 as an example to provide a detailed illustrative description of its specific features.

[0059] like Figure 4 As shown, the square single cell 530 includes: an end cap assembly 100, a housing, and an electrode assembly. The housing has an opening for receiving space, the electrode assembly is disposed in the receiving space of the housing, and the end cap assembly 100 covers the opening of the housing.

[0060] It should be noted that the square single-cell battery 530 can be a tetragonal prism-shaped battery, which is convenient for assembly into groups. A tetragonal prism-shaped battery refers to a battery with a prism shape, but it is not strictly limited that each side of the prism must be a straight line in the strict sense; the corners between the sides can be right angles, rounded corners, or chamfers. The casing and end cap assembly 100 cooperate to form a tetragonal prism-shaped outer shell. The square single-cell battery 530 includes an electrode assembly and an electrolyte located within the casing. The electrode assembly includes a cell, a positive electrode tab, and a negative electrode tab. The cell has positive and negative electrode plates stacked on top of each other, and a separator sheet disposed between the positive and negative electrode plates. The positive and negative electrode plates, as well as the separator sheet disposed between the positive and negative electrode plates, are wound together to obtain a wound cell. Optionally, the cell can be a stacked cell.

[0061] Among them, such as Figures 4-6 As shown, the end cap assembly 100 includes an aluminum sheet 120, a first electrode post 141, a second electrode post 142, and a lower plastic 110. The aluminum sheet 120 and the lower plastic 110 have through-holes 1151 and 1152 for connecting the first and second electrodes, respectively. The first electrode post 141 passes through the first electrode post connecting hole 1151, and the second electrode post 142 passes through the second electrode post connecting hole 1152. The aluminum sheet 120 has a top surface and a back surface along the second direction Z. The top surface is located on the side of the aluminum sheet 120 facing away from the electrode assembly, and the back surface is located on the side of the aluminum sheet 120 facing the electrode assembly. The lower plastic 110 is stacked on the back surface of the aluminum sheet 120 along the second direction Z to insulate the aluminum sheet 120 from the electrode assembly. The first electrode post 141 and the second electrode post 142 have opposite polarities; for example, the first electrode post 141 can be a positive electrode post, and the second electrode post 142 can be a negative electrode post.

[0062] The electrode assembly includes at least one battery cell and multiple tabs connected to the battery cell, the multiple tabs including at least one positive tab and at least one negative tab; the end cap assembly 100 includes multiple adapter pieces, the multiple adapter pieces including at least one first adapter 151 and at least one second adapter 152; the positive tab of each battery cell is electrically connected to the first terminal 141 through the first adapter 151, and the negative tab of each battery cell is electrically connected to the second terminal 142 through the second adapter 152.

[0063] Among them, such as Figure 6 As shown, both the first adapter 151 and the second adapter 152 can be composed of a tab connection portion and a post connection portion, i.e., the whole is L-shaped. The positive and negative tabs on the electrode assembly are arranged on both sides along the first direction X. The tab connection portion of the first adapter 151 extends along the second direction Z and connects to the side-exiting positive tab; the tab connection portion of the second adapter 152 extends along the second direction Z and connects to the side-exiting negative tab.

[0064] Among them, such as Figures 4-6As shown, the aluminum sheet 120 has explosion-proof holes, and the explosion-proof valve 130 can be installed on the explosion-proof holes by welding or other methods; alternatively, the explosion-proof valve 130 can be installed by forming grooves on the aluminum sheet 120 and using the grooved area as the explosion-proof valve. The lower plastic sheet 110 has an explosion-proof mesh 1190, which is located below the aluminum sheet 120 along the second direction Z. Therefore, the explosion-proof holes on the aluminum sheet 120 are located above the explosion-proof mesh 1190 on the lower plastic sheet 110, meaning the explosion-proof valve is located above the explosion-proof mesh 1190. When the gas pressure inside the single cell 530 exceeds a set critical value, the explosion-proof valve 130 opens, and the high-temperature, high-pressure gas inside the single cell 530 is discharged through the explosion-proof mesh 1190 and the explosion-proof valve 130 to prevent an explosion due to excessive internal pressure in the single cell 530.

[0065] Currently, due to user demand for large-capacity single-cell batteries 530, the length of single-cell batteries 530 in the first direction X is becoming increasingly longer. However, as... Figure 5 and Figure 6 As shown, when the length of the single cell 530 increases, the length of the end cap assembly 100 in the first direction X will inevitably become longer, that is, the length of the lower plastic 110 in the end cap assembly 100 will also become longer. Since the lower plastic 110 is usually formed by injection molding, the longer lower plastic 110 is prone to bending and deformation under the internal stress after injection molding, which will affect the product yield, and thus affect the production efficiency and production cost.

[0066] In this regard, embodiments of the present disclosure provide a lower plastic, such as Figures 7-13 As shown, the lower plastic body 110 includes: a lower plastic body 1110, a first boss 1131, a second boss 1132, a first protruding edge 1141, and a second protruding edge 1142. The lower plastic body 1110 has a first end 1121 and a second end 1122 along a first direction X, a first surface 1123 and a second surface 1124 along a second direction Z, and a first side edge 1125 and a second side edge 1126 along a third direction Y. The first direction X, the second direction Z, and the third direction Y intersect each other. The first boss 1131 and the second boss... 1132 is located on the second surface 1124 of the lower plastic body 1110, and the first boss 1131 and the second boss 1132 protrude in a direction perpendicular to the second surface 1124; the first boss 1131 is disposed near the first end 1121, and the second boss 1132 is disposed near the second end 1122; the first protruding edge 1141 and the second protruding edge 1142 are located on the second surface 1124 of the lower plastic body 1110, and the first protruding edge 1141 is disposed on the first side 1125, and the second protruding edge 1142 is disposed on the second side 1126.

[0067] Specifically, in the second direction Z, the height of the first boss 1131 is greater than or equal to twice the height of the first protruding edge 1141 and greater than or equal to twice the height of the second protruding edge 1142; the height of the second boss 1132 is greater than or equal to twice the height of the first protruding edge 1141 and greater than or equal to twice the height of the second protruding edge 1142. For example, as... Figure 14 and Figure 15 As shown, the height of the first boss 1131 and the second boss 1132 can be H, and the height of the first protrusion 1141 and the second protrusion 1142 can be h, where H≥2h.

[0068] In the third direction Y, the width of the first boss 1131 and the width of the second boss 1132 are both less than or equal to the distance between the first protruding edge 1141 and the second protruding edge 1142. For example, as shown... Figure 14 and Figure 15 As shown, the width of the lower plastic body 1110 can be W, the width of the first boss 1131 and the second boss 1132 can be w, and the width of the first protruding edge 1141 and the second protruding edge 1142 can be t, where w≤W-2t.

[0069] The lower plastic body 110 provided in this disclosure has a first protrusion 1131 and a second protrusion 1132 at both ends. The width of the first protrusion 1131 and the width of the second protrusion 1132 are both less than or equal to the distance between the first protruding edge 1141 and the second protruding edge 1142. Therefore, when the second surfaces 1124 of the two lower plastic bodies 110 are fastened together, the first protrusion 1131 and the second protrusion 1132 on the upper lower plastic body 110 can extend into the distance between the first protruding edge 1141 and the second protruding edge 1142 on the lower lower plastic body 110. The first protrusion 1131 and the second protrusion 1132 on the lower plastic 110 can extend between the first protruding edge 1141 and the second protruding edge 1142 on the upper lower plastic 110. That is, the first protrusion 1131 and the second protrusion 1132 on the upper lower plastic 110 are misaligned with the first protrusion 1131 and the second protrusion 1132 on the lower lower plastic 110. At the same time, since the height of the first protrusion 1131 and the height of the second protrusion 1132 are both greater than or equal to twice the height of the first protruding edge 1141 and the second protruding edge 1142, the protrusions on the lower plastic 110 are also misaligned. The height is twice that of the upper plastic 110. Therefore, when the two lower plastic 110s are fastened together, there can be a gap between the first protruding edge 1141 on the upper lower plastic 110 and the corresponding first protruding edge 1141 on the lower lower plastic 110, and there can be a gap between the second protruding edge 1142 on the upper lower plastic 110 and the corresponding second protruding edge 1142 on the lower lower plastic 110. At this time, by applying an external force to the two fastened lower plastic 110s in the second direction Z, the first protruding edge 1141 on the upper lower plastic 110 can be... 1. The first protruding edge 1141 on the corresponding lower plastic 110 is brought close to and abuts against each other, and the second protruding edge 1142 on the upper lower plastic 110 is brought close to and abuts against the corresponding lower plastic 110. After a long period of correction, the two lower plastics 110 that are fastened together can release the stored internal stress, thereby overcoming the bending phenomenon caused by the injection molding internal stress of the lower plastic 110, improving the flatness of the lower plastic 110, and thus improving the process yield and assembly stability of the lower plastic 110.

[0070] It is understandable that the height of the first protrusion 1131 and the height of the second protrusion 1132 are both greater than twice the height of the first protrusion 1141 and twice the height of the second protrusion 1142. The higher the height of the first protrusion 1131 and the second protrusion 1132, the larger the gap between the first protrusion 1141 on the upper lower plastic 110 and the corresponding first protrusion 1141 on the lower lower plastic 110, and the larger the gap between the second protrusion 1142 on the upper lower plastic 110 and the corresponding second protrusion 1142 on the lower lower plastic 110. When the gap is larger, the bending stress generated by the external force when the two lower plastics 110 are fastened together is greater, which can more effectively release the internal stress generated by the injection molding of the lower plastics 110.

[0071] In some embodiments, such as Figures 5-8 As shown, the lower plastic body 1110 includes a first body portion 1111 and a second body portion 1112, which are separately arranged along a first direction X. The length of the first body portion 1111 in the first direction X is greater than the length of the second body portion 1112. A first boss 1131 is located on the first body portion 1111, and a second boss 1132 is located on the second body portion 1112. By dividing the lower plastic body 110 into two separate independent parts, compared to a one-piece lower plastic body 110, the lengths of the first body portion 1111 and the second body portion 1112 are shorter, effectively improving the bending caused by the excessive length of the lower plastic body 110. Since the length of the first body portion 1111 is greater than the length of the second body portion 1112, structures such as an explosion-proof mesh 1190 and a liquid injection hole can be provided on the second body portion 1112, thereby minimizing the length of the second body portion 1112 and further reducing the bending caused by its excessive length, thus improving product yield.

[0072] Among them, such as Figure 8 and Figure 9 As shown, the explosion-proof mesh 1190 is disposed on the first body portion 1111, and is located at the end away from the first protrusion 1131 along the first direction X; in the second direction Z, the height of the explosion-proof mesh 1190 is equal to the height of the first protrusion 1131; in the third direction Y, the width of the explosion-proof mesh 1190 is less than or equal to the distance between the first protruding edge 1141 and the second protruding edge 1142. Figures 9-13As shown, when the second surfaces 1124 of the two lower plastic parts 110 are fastened together, the first body portion 1111 of the upper lower plastic part 110 fastens with the first body portion 1111 of the lower lower plastic part 110, and the second body portion 1112 of the upper lower plastic part 110 fastens with the second body portion 1112 of the lower lower plastic part 110. The first boss 1131 and the explosion-proof mesh 1190 on the upper first body portion 1111 can extend between the first protruding edge 1141 and the second protruding edge 1142 on the lower first body portion 1111, and similarly, the first boss 1131 and the explosion-proof mesh 1190 on the lower first body portion 1111 can extend between the first protruding edge 1141 and the second protruding edge 1142 on the upper first body portion 1111.

[0073] In the first direction X, the distance between the side of the explosion-proof mesh 1190 away from the first protrusion 1131 and the end of the first body part 1111 away from the first protrusion 1131 is greater than the distance between the side of the first protrusion 1131 near the explosion-proof mesh 1190 and the end of the first body part 1111 away from the explosion-proof mesh 1190. That is, the first protrusion 1131 on the upper first body part 1111 and the explosion-proof mesh 1190 on the lower first body part 1111 are located at the same end along the first direction X and are staggered. Therefore, when the two first body parts 1111 are fastened together, there can be a gap between the first protruding edge 1141 on the upper first body part 1111 and the corresponding first protruding edge 1141 on the lower first body part 1111, and there can be a gap between the second protruding edge 1142 on the upper first body part 1111 and the corresponding second protruding edge 1142 on the lower first body part 1111.

[0074] Similarly, the second protrusion 1132 on the upper second body portion 1112 can extend between the first protrusion 1141 and the second protrusion 1142 on the lower second body portion 1112, and the second protrusion 1132 on the lower second body portion 1112 can extend between the first protrusion 1141 and the second protrusion 1142 on the upper second body portion 1112. The second protrusion 1132 on the upper second body portion 1112 and the second protrusion 1132 on the lower second body portion 1112 are spaced apart at both ends along the first direction X, so that after the two second body portions 1112 are fastened together, there can be a gap between the first protrusion 1141 on the upper second body portion 1112 and the corresponding first protrusion 1141 on the lower second body portion 1112, and there can be a gap between the second protrusion 1142 on the upper second body portion 1112 and the corresponding second protrusion 1142 on the lower second body portion 1112.

[0075] At this time, by applying an external force to the two first body parts 1111 and two second body parts 1112 that are fastened together in the second direction Z, the first protrusion 1141 on the upper first body part 1111 and the second body part 1112 can be brought close to and abutted together with the corresponding first protrusion 1141 on the lower first body part 1111 and the second body part 1112, and the second protrusion 1142 on the upper first body part 1111 and the second body part 1112 can be brought close to and abutted together with the corresponding second protrusion 1142 on the lower first body part 1111 and the second body part 1112. After a long period of correction, the internal stress stored in the two first body parts 1111 and the two second body parts 1112 that are fastened together can be released, thereby overcoming the bending phenomenon of the lower plastic 110 caused by the injection molding internal stress.

[0076] In some embodiments, such as Figure 9 As shown, a groove 1191 is provided on the first surface 1123 of the first body 1111 at a position corresponding to the explosion-proof mesh 1190. By providing the clearance groove 1191, clearance space is provided for the explosion-proof valve 130, preventing direct contact between the explosion-proof valve 130 and the lower plastic 110, which could lead to abnormal valve opening and improve the reliability of the explosion-proof valve 130. Furthermore, the clearance groove 1191 forms an additional gas channel between the explosion-proof valve 130 and the first surface 1123 of the lower plastic 110. Gas can pass through the clearance groove 1191 and be discharged from the opened explosion-proof valve 130, reducing exhaust resistance, ensuring the unobstructed flow of the pressure relief channel, and improving pressure relief efficiency.

[0077] The size and position of the clearance groove 1191 can be matched with the shape and installation position of the explosion-proof valve 130, and the clearance groove 1191 forms a clearance for the installation of the explosion-proof valve 130; in addition, the side wall of the clearance groove 1191 enables lateral positioning assembly, ensuring that the explosion-proof valve 130 and the explosion-proof mesh 1190 are completely aligned in the vertical direction, and the gas can directly enter the explosion-proof valve 130 after being discharged from the explosion-proof mesh 1190.

[0078] In some embodiments, in the second direction Z, the height of the first protruding edge 1141 and / or the second protruding edge 1142 is greater than or equal to 3 mm, for example, 3 mm, 4 mm, 5 mm, etc. By making the height of the first protruding edge 1141 and / or the second protruding edge 1142 greater than or equal to 3 mm, the skirt of the lower plastic 110 formed by the first protruding edge 1141 and the second protruding edge 1142 has sufficient height to provide a sufficient area for heat fusion with the Mylar film (polyester film), thereby avoiding insufficient heat fusion position of the skirt of the lower plastic 110 with the Mylar film. In addition, the height of the first protruding edge 1141 and the second protruding edge 1142 is greater than or equal to 3 mm, and the moment of inertia of the cross sections of the first protruding edge 1141 and the second protruding edge 1142 is significantly increased, which can withstand greater horizontal force, form more stable lateral support ribs, and greatly enhance the deformation resistance of the lower plastic 110 in the horizontal direction, thereby improving the bending phenomenon of the lower plastic 110 caused by injection molding internal stress.

[0079] In some embodiments, in the third direction Y, the thickness of the first protruding edge 1141 is greater than or equal to half the height of the first boss 1131, and / or the thickness of the second protruding edge 1142 is greater than or equal to half the height of the second boss 1132. By making the thickness of the first protruding edge 1141 greater than or equal to half the height of the first protruding edge 1141, and / or the thickness of the second protruding edge 1142 greater than or equal to half the height of the second protruding edge 1142, the moment of inertia of the cross sections of the first protruding edge 1141 and the second protruding edge 1142 can be further increased, enabling the first protruding edge 1141 and the second protruding edge 1142 to withstand greater horizontal forces. By forming a more stable lateral support rib through the first protruding edge 1141 and the second protruding edge 1142, the deformation resistance of the lower plastic 110 in the horizontal direction is further improved, thereby further improving the bending phenomenon of the lower plastic 110 caused by injection molding internal stress.

[0080] In some embodiments, such as Figure 14 and Figure 15As shown, the first end 1121 of the lower plastic body 1110 is provided with a first pole post connection hole 1151, and the second end 1122 is provided with a second pole post connection hole 1152; the first boss 1131 is located on the side of the first pole post connection hole 1151 close to the second pole post connection hole 1152, and the second boss 1132 is located on the side of the second pole post connection hole 1152 close to the first pole post connection hole 1151.

[0081] Among them, such as Figure 14 and Figure 15 As shown, at least one first positioning post 1161 is provided on the second surface 1124 of the first end 1121 of the lower plastic body 1110. The first positioning post 1161 is disposed near the first pole post connecting hole 1151, and the first positioning post 1161 and the first pole post connecting hole 1151 are located on the same side of the first boss 1131 along the first direction X; and / or, at least one second positioning post 1162 is provided on the second surface 1124 of the second end 1122 of the lower plastic body 1110. The second positioning post 1162 is disposed near the second pole post connecting hole 1152, and the second positioning post 1162 and the second pole post connecting hole 1152 are located on the same side of the second boss 1132 along the first direction X. Figure 16 and Figure 17 As shown, when the first adapter 151 is connected to the first pole post 141, it is positioned and assembled on the lower plastic 110 by the first positioning post 1161; when the second adapter 152 is connected to the second pole post 142, it is positioned and assembled on the lower plastic 110 by the second positioning post 1162. For example, two first positioning posts 1161 and two second positioning posts 1162 may be provided respectively, and two positioning notches may be provided on the pole post connection portions of the first adapter 151 and the second adapter 152 respectively, achieving positioning and assembly through the cooperation of the positioning posts and positioning notches.

[0082] In some embodiments, such as Figure 14 and Figure 15 As shown, at least two first positioning baffles 1171 are provided on the second surface 1124 of the first end 1121 of the lower plastic body 1110, and the at least two first positioning baffles 1171 are arranged opposite each other along the third direction Y; in the third direction Y, a first reinforcing plate 1173 is provided on the side of the first positioning baffle 1171 opposite to the second positioning baffle 1172. And / or, at least two second positioning baffles 1172 are provided on the second surface 1124 of the second end 1122 of the lower plastic body 1110, and the at least two second positioning baffles 1172 are arranged opposite each other along the third direction Y; in the third direction Y, a second reinforcing plate 1174 is provided on the side of the second positioning baffle 1172 opposite to the first positioning baffle 1171. Figure 16 and Figure 17As shown, the first positioning baffle 1171 limits the position of the pole connection between the first adapter 151 and the second adapter 152 in the third direction Y when they are mounted on the lower plastic 110, thereby improving the assembly accuracy of the first adapter 151 and the second adapter 152 on the lower plastic 110. Furthermore, the first reinforcing plate 1173 on the side of the first positioning baffle 1171 opposite to the second positioning baffle 1172 enhances the structural strength of the first positioning baffle 1171 on the first body 1111; and the second reinforcing plate 1174 on the side of the second positioning baffle 1172 opposite to the first positioning baffle 1171 enhances the structural strength of the second positioning baffle 1172 on the second body 1112.

[0083] Specifically, along the third direction Y, two first positioning baffles 1171 may be provided on the first body part 1111, and the two first positioning baffles 1171 are arranged opposite each other along the third direction Y, so as to be located on both sides of the pole post connection part of the first adapter 151; and / or, along the third direction Y, two second positioning baffles 1172 may be provided on the second body part 1112, and the two second positioning baffles 1172 are arranged opposite each other along the third direction Y, so as to be located on both sides of the pole post connection part of the second adapter 152.

[0084] The two first positioning baffles 1171 may have inclined surfaces on their opposing surfaces. The inclined surfaces cause the distance between the two first positioning baffles 1171 to gradually increase in the direction away from the second surface 1124. In other words, the inclined surfaces form a guide surface, which facilitates the position of the pole connecting part of the first adapter 151 between the two first positioning baffles 1171. Similarly, the two second positioning baffles 1172 may also have inclined surfaces on their opposing surfaces. The inclined surfaces cause the distance between the two second positioning baffles 1172 to gradually increase in the direction away from the second surface 1124. In other words, the inclined surfaces form a guide surface, which facilitates the position of the pole connecting part of the second adapter 152 between the two second positioning baffles 1172.

[0085] Among them, such as Figure 14 As shown, along the first direction X, the first positioning post 1161 and the first positioning baffle 1171 are located on both sides of the first pole post connecting hole 1151, and the first positioning baffle 1171 is located on the side of the first positioning post 1161 away from the first boss 1131; Figure 15As shown, the second positioning post 1162 and the second positioning baffle 1172 are located on both sides of the second pole post connecting hole 1152, and the second positioning baffle 1172 is located on the side of the second positioning post 1162 away from the second boss 1132. Through the cooperation of the first positioning post 1161 and the first positioning baffle 1171, the pole post connecting part of the first adapter 151 is limited on the first body part 1111 along the first direction X and the third direction Y, thereby allowing the pole post connecting part of the first adapter 151 to be precisely assembled on the lower plastic 110. Similarly, through the cooperation of the second positioning post 1162 and the second positioning baffle 1172, the pole post connecting part of the second adapter 152 is limited on the second body part 1112 along the first direction X and the third direction Y, thereby allowing the pole post connecting part of the second adapter 152 to be precisely assembled on the lower plastic 110.

[0086] In some embodiments, a first support structure is provided on the second surface 1124 of the first end 1121 of the lower plastic body 1110, and the first support structure is located along the first direction X on the side of the first pole post connection hole 1151 away from the first boss 1131; and / or, such as Figure 15 As shown, a second support structure 1180 is provided on the second surface 1124 of the second end 1122 of the lower plastic body 1110. The second support structure 1180 is located along the first direction X on the side of the second pole post connection hole 1152 away from the second boss 1132. Figure 17 As shown, when the second adapter 152 provided on the second body portion 1112 is a negative adapter, the second end 1122 of the second body portion 1112 is provided with a second support structure 1180. Since the negative adapter is typically made of copper and the positive adapter is typically made of aluminum, the negative adapter is heavier than the positive adapter. Furthermore, because the second adapter 152, composed of the tab connection portion and the post connection portion, is generally L-shaped, the tab connection portion of the second adapter 152 tends to tilt away from the post connection portion along the first direction X, which can lead to a deviation in the connection position between the tab connection portion and the second post 142. By providing the second support structure 1180, a support force of at least along the first direction X can be provided to the second adapter 152, thereby overcoming the tendency of the tab connection portion of the second adapter 152 to tilt away from the post connection portion along the first direction X. Furthermore, by cooperating with the second support structure 1180 and the second positioning post 1162, the electrode connecting portion of the second adapter 152 is positioned and assembled in the first direction X, thereby improving the assembly accuracy of the second adapter 152 on the second body portion 1112. Similarly, the first adapter 151 can also be assembled on the first body portion 1111 using the above-mentioned support structure, and this disclosure does not impose any limitations on this.

[0087] Among them, such as Figure 15As shown, the first support structure has a first support surface facing the first boss 1131, and the angle between the first support surface and the second surface 1124 is an obtuse angle; and / or, the second support structure 1180 has a second support surface 1181 facing the second boss 1132, and the angle between the second support surface 1181 and the second surface 1124 is an obtuse angle. Figure 17 As shown, since the connection between the pole post and the tab of the second adapter 152 is bent at 90 degrees, the surface at the bend is inclined. By making the angle between the second support surface 1181 and the second surface 1124 obtuse, that is, the second support surface 1181 is an inclined surface facing the bend on the second adapter 152, the inclined surface of the second support structure 1180 matches the inclined surface on the second adapter 152, which increases the contact area between the second support structure 1180 and the second adapter 152, thereby improving the stability of the supporting force provided by the second support structure 1180 to the second adapter 152. In addition, the obtuse angle support surface design provides an inclined guide for the assembly of the lower plastic 110 and the adapter, reducing the assembly difficulty and improving the assembly efficiency.

[0088] In this disclosure, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise expressly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0089] In the description of the embodiments of this disclosure, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0090] In the description of this disclosure, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the implementation of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0091] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

[0092] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A type of plastic for use in an energy storage device (10), characterized in that, The lower plastic (110) includes: The lower plastic body (1110) has a first end (1121) and a second end (1122) along a first direction (X), a first surface (1123) and a second surface (1124) along a second direction (Z), and a first side (1125) and a second side (1126) along a third direction (Y); the first direction (X), the second direction (Z), and the third direction (Y) intersect each other; A first protrusion (1131) and a second protrusion (1132) are located on the second surface (1124) of the lower plastic body (1110), with the first protrusion (1131) being disposed near the first end (1121) and the second protrusion (1132) being disposed near the second end (1122). A first protruding edge (1141) and a second protruding edge (1142) are located on the second surface (1124) of the lower plastic body (1110) and protrude in a direction perpendicular to the second surface (1124); the first protruding edge (1141) is provided on the first side edge (1125) and the second protruding edge (1142) is provided on the second side edge (1126); In the second direction (Z), the height of the first boss (1131) is greater than or equal to twice the height of the first protruding edge (1141) and twice the height of the second protruding edge (1142), and the height of the second boss (1132) is greater than or equal to twice the height of the first protruding edge (1141) and twice the height of the second protruding edge (1142); in the third direction (Y), the width of the first boss (1131) and the width of the second boss (1132) are both less than or equal to the distance between the first protruding edge (1141) and the second protruding edge (1142).

2. The lower plastic according to claim 1, characterized in that, In the second direction (Z), the height of the first convex edge (1141) and / or the second convex edge (1142) is greater than or equal to 3 mm.

3. The lower plastic according to claim 1, characterized in that, In the third direction (Y), the thickness of the first protrusion (1141) is greater than or equal to half the height of the first protrusion (1141), and / or the thickness of the second protrusion (1142) is greater than or equal to half the height of the second protrusion (1142).

4. The lower plastic according to claim 1, characterized in that, The first end (1121) of the lower plastic body (1110) is provided with a first pole post connection hole (1151), and the second end (1122) is provided with a second pole post connection hole (1152); the first boss (1131) is located on the side of the first pole post connection hole (1151) close to the second pole post connection hole (1152), and the second boss (1132) is located on the side of the second pole post connection hole (1152) close to the first pole post connection hole (1151).

5. The lower plastic according to claim 4, characterized in that, At least one first positioning post (1161) is provided on the second surface (1124) of the first end (1121) of the lower plastic body (1110). The first positioning post (1161) is located near the first pole post connecting hole (1151), and the first positioning post (1161) and the first pole post connecting hole (1151) are located on the same side of the first boss (1131) along the first direction (X); and / or, At least one second positioning post (1162) is provided on the second surface (1124) of the second end (1122) of the lower plastic body (1110). The second positioning post (1162) is located near the second pole post connection hole (1152), and the second positioning post (1162) and the second pole post connection hole (1152) are located on the same side of the second boss (1132) along the first direction (X).

6. The lower plastic according to claim 5, characterized in that, At least two first positioning baffles (1171) are provided on the second surface (1124) of the first end (1121) of the lower plastic body (1110), and the at least two first positioning baffles (1171) are arranged opposite to each other along the third direction (Y); in the third direction (Y), a first reinforcing plate (1173) is provided on the side of the first positioning baffle (1171) away from the other first positioning baffle (1171); and / or, At least two second positioning baffles (1172) are provided on the second surface (1124) of the second end (1122) of the lower plastic body (1110), and the at least two second positioning baffles (1172) are arranged opposite to each other along the third direction (Y); in the third direction (Y), a second reinforcing plate (1174) is provided on the side of the second positioning baffle (1172) away from the other second positioning baffle (1172).

7. The lower plastic according to claim 6, characterized in that, Along the first direction (X), the first positioning post (1161) and the first positioning baffle (1171) are located on both sides of the first pole post connecting hole (1151), and the first positioning baffle (1171) is located on the side of the first positioning post (1161) away from the first boss (1131); and / or, Along the first direction (X), the second positioning post (1162) and the second positioning baffle (1172) are located on both sides of the second pole post connecting hole (1152), and the second positioning baffle (1172) is located on the side of the second positioning post (1162) away from the second boss (1132).

8. The lower plastic according to claim 4, characterized in that, A first support structure is provided on the second surface (1124) of the first end (1121) of the lower plastic body (1110), and the first support structure is located on the side of the first pole post connection hole (1151) away from the first boss (1131) along the first direction (X); and / or, a second support structure (1180) is provided on the second surface (1124) of the second end (1122) of the lower plastic body (1110), and the second support structure (1180) is located on the side of the second pole post connection hole (1152) away from the second boss (1132) along the first direction (X).

9. The lower plastic according to claim 8, characterized in that, The first support structure has a first support surface facing the first boss (1131), and the angle between the first support surface and the second surface (1124) is an obtuse angle; and / or, the second support structure (1180) has a second support surface (1181) facing the second boss (1132), and the angle between the second support surface (1181) and the second surface (1124) is an obtuse angle.

10. The lower plastic according to claim 1, characterized in that, The lower plastic body (1110) includes a first body part (1111) and a second body part (1112) separately arranged along the first direction (X). The length of the first body part (1111) is greater than the length of the second body part (1112) in the first direction (X). The first boss (1131) is located on the first body part (1111), and the second boss (1132) is located on the second body part (1112).

11. The lower plastic according to claim 10, characterized in that, The lower plastic (110) also includes: An explosion-proof mesh (1190) is disposed on the first body part (1111) and located at the end away from the first boss (1131) along the first direction (X); in the second direction (Z), the height of the explosion-proof mesh (1190) is equal to the height of the first boss (1131); in the third direction (Y), the width of the explosion-proof mesh (1190) is less than or equal to the distance between the first protruding edge (1141) and the second protruding edge (1142).

12. The lower plastic according to claim 11, characterized in that, The first surface (1123) of the first body part (1111) is provided with a relief groove (1191) that matches the shape of the explosion-proof valve at the position corresponding to the explosion-proof mesh (1190).

13. The lower plastic according to claim 11, characterized in that, In the first direction (X), the distance between the side of the explosion-proof mesh (1190) away from the first boss (1131) and the end of the first body part (1111) away from the first boss (1131) is greater than the distance between the side of the first boss (1131) close to the explosion-proof mesh (1190) and the end of the first body part (1111) away from the explosion-proof mesh (1190).

14. An end cap assembly, characterized in that, Includes the lower plastic (110) as described in any one of claims 1 to 13.

15. An energy storage device, characterized in that, include: A housing having an opening for receiving space; An electrode assembly disposed in the receiving space; The end cap assembly (100) of claim 14, the end cap assembly (100) covering the opening.

16. An energy storage system, characterized in that, Includes the energy storage device (10) as described in claim 15.

Images