CN116780127A

CN116780127A - Lower plastic, end cover assembly, energy storage device and electric equipment

Info

Publication number: CN116780127A
Application number: CN202311032256.6A
Authority: CN
Inventors: 李茂松; 檀基本
Original assignee: Shenzhen Haichen Energy Storage Control Technology Co ltd; Xiamen Hithium Energy Storage Technology Co Ltd
Current assignee: Shenzhen Haichen Energy Storage Control Technology Co ltd; Xiamen Hithium Energy Storage Technology Co Ltd
Priority date: 2023-08-16
Filing date: 2023-08-16
Publication date: 2023-09-19

Abstract

The application discloses lower plastic, an end cover assembly, an energy storage device and electric equipment, wherein the lower plastic comprises a first surface and a second surface, and the first surface and the second surface are oppositely arranged along the thickness direction of the lower plastic; the first surface is provided with an indent, and the second surface is convexly provided with a convex hull; the orthographic projection of the convex hull on the first surface completely covers the indentation. The convex hull can increase the structural strength of plastic under on the one hand for the structure of plastic is more stable down, reduces the risk that plastic damaged down, in addition, the convex hull still makes plastic easy to process down, and the cost is lower.

Description

Lower plastic, end cover assembly, energy storage device and electric equipment

Technical Field

The application relates to the technical field of energy storage, in particular to a lower plastic, an end cover assembly, an energy storage device and electric equipment.

Background

The conventional energy storage device generally comprises a lower plastic, which is in a rectangular sheet shape, and has a longer length and a thinner thickness. At present, the lower plastic is generally prepared by adopting an injection molding mode, however, at present, when the lower plastic is subjected to injection molding, the speed of filling the molding cavity of the mold with molten plastic liquid is lower, so that the efficiency and uniformity of the lower plastic molding are poorer, and the lower plastic production yield is lower.

Disclosure of Invention

The application aims to provide lower plastic, an end cover assembly, an energy storage device and electric equipment, and molten plastic liquid can quickly fill a forming cavity of a die, so that the efficiency and uniformity of lower plastic forming are improved, and the production yield of lower plastic is improved.

The first aspect of the present application provides a lower plastic, which includes a first surface and a second surface, and the first surface and the second surface are disposed opposite to each other along a thickness direction of the lower plastic; the first surface is provided with an indent, and the second surface is convexly provided with a convex hull; an orthographic projection of the convex hull on the first surface completely covers the dimple.

In some embodiments, the convex hull is hemispherical.

In some embodiments, the convex hull has a diameter between 3.4 millimeters and 3.8 millimeters.

In some embodiments, the second surface includes a first edge and a second edge, the first edge and the second edge are opposite along a length direction of the lower plastic, and a distance from the convex hull to the first edge is the same as a distance from the convex hull to the second edge.

In some embodiments, the number of the indentations is two, the number of the convex hulls is two, and the number of the convex hulls is two, and the number of the convex hulls is two; orthographic projection of the first convex hull on the first surface completely covers the first indent; orthographic projection of the second convex hull on the first surface completely covers the second indent; the first convex hull and the second convex hull are arranged at intervals along the length direction of the lower plastic.

In some embodiments, the first surface further includes a third edge and a fourth edge, the third edge and the fourth edge are opposite to each other along the length direction of the lower plastic, and the third edge, the first convex hull, the second convex hull and the fourth edge are sequentially arranged along the length direction of the lower plastic; in the length direction of the lower plastic, the distance between the third edge and the first convex hull is a first distance, the distance between the first convex hull and the second convex hull is a second distance, the distance between the second convex hull and the fourth edge is a third distance, and the first distance, the second distance and the third distance are the same.

In some embodiments, the lower plastic body is further provided with an explosion-proof fence, and the explosion-proof fence is recessed from the first surface toward the second surface and is raised relative to the second surface; the explosion-proof fence is provided with a concave cavity penetrating through the first surface; the explosion-proof fence comprises an explosion-proof bottom plate, the explosion-proof bottom plate and the second surface are arranged at intervals along the thickness direction of the lower plastic, and the explosion-proof bottom plate is provided with through holes.

In some embodiments, the explosion-proof fence further includes a first side plate and a second side plate, the first side plate and the second side plate are opposite to each other along the length direction of the lower plastic, and the first side plate and the second side plate are respectively connected with two sides of the explosion-proof bottom plate along the length direction of the lower plastic; the first side plate and the second side plate are inclined relative to the thickness direction of the lower plastic, and the inclination directions of the first side plate and the second side plate are opposite; the first side plate and the second side plate are gradually close to each other in a direction pointing to the explosion-proof bottom plate from the second surface.

In some embodiments, the junction of the first side panel and the explosion-proof bottom panel facing away from the recessed cavity transitions with a first arcuate surface; the second side plate and the explosion-proof bottom plate are in transition with a second arc surface at the joint of the concave cavity.

In some embodiments, the lower plastic is provided with a first notch and a second notch, and the first notch is concavely arranged on the first surface and penetrates through the first side plate along the length direction of the lower plastic; the second notch is concavely arranged on the first surface and penetrates through the second side plate along the length direction of the lower plastic.

In some embodiments, a reinforcing rib is arranged in the concave cavity, the reinforcing rib is vertically fixed on the explosion-proof bottom plate, and the reinforcing rib is fixed with the first side plate and the second side plate.

In some embodiments, the thickness dimension of the stiffener is gradually reduced in the thickness direction of the lower plastic, and the thickness of the bottom of the stiffener is greater than the thickness dimension of the top of the stiffener.

In some embodiments, the stiffener includes a first stiffener plate and a second stiffener plate; the first reinforcing plates and the second reinforcing plates are arranged at intervals along the width direction of the lower plastic; the first reinforcing plate and the second reinforcing plate extend along the length direction of the lower plastic, and the opposite ends of the first reinforcing plate and the second reinforcing plate are connected with the first side plate and the second side plate.

In some embodiments, the reinforcing rib further includes a third reinforcing plate extending in a width direction of the lower plastic, and opposite ends of the third reinforcing plate are respectively fixed to the first reinforcing plate and the second reinforcing plate.

In some embodiments, the top of the first reinforcing plate is flush with the first surface and the top of the second reinforcing plate is flush with the first surface.

In some embodiments, the top of the third stiffener is lower than the top of the first stiffener.

A second aspect of the application provides an end cap assembly comprising: the lower plastic of any one of the first aspects of the present application, and a top cover; the lower plastic cement is arranged on the surface of the top cover, and the first surface is abutted against the top cover.

In some embodiments, the lower plastic body is further provided with an explosion-proof fence, and the explosion-proof fence is recessed from the first surface toward the second surface and is raised relative to the second surface; the explosion-proof fence is provided with a concave cavity penetrating through the first surface; a first reinforcing plate and a second reinforcing plate are arranged in the concave cavity; the top of the first reinforcing plate is flush with the first surface, and the top of the first reinforcing plate is abutted with the top cover; the top of the second reinforcing plate is flush with the first surface, and the top of the second reinforcing plate is abutted with the top cover.

In some embodiments, a third reinforcing plate is further arranged in the concave cavity, the top of the third reinforcing plate is lower than the top of the first reinforcing plate, and the top cover is connected with an explosion-proof valve; the third reinforcing plate faces the explosion-proof valve, and a gap is reserved between the top of the third reinforcing plate and the explosion-proof valve.

In some embodiments, the explosion-proof valve is located between the first reinforcing plate and the second reinforcing plate along the width direction of the lower plastic, and a space is formed between the welding mark of the explosion-proof valve and the first reinforcing plate; and a space is reserved between the welding mark of the explosion-proof valve and the second reinforcing plate.

A third aspect of the present application provides an energy storage device comprising a housing having an opening, the housing being provided with a receiving cavity, an electrode assembly received in the receiving cavity, and an end cap assembly as claimed in any one of claims to covering the opening.

A fourth aspect of the application provides a powered device comprising an energy storage device as claimed in claim, the energy storage device being arranged to store electrical energy.

In the application, the convex hull can increase the structural strength of the lower plastic on one hand, so that the structure of the lower plastic is more stable, the risk of damage of the lower plastic is reduced, and in addition, the convex hull also enables the lower plastic to be easy to process and has lower cost.

Specifically, the mould for preparing the lower plastic is provided with a forming cavity, the top of the forming cavity is provided with a liquid filling port, the bottom of the forming cavity is concavely provided with an injection molding groove, the shape of the injection molding groove is adapted to that of the convex hull, and the liquid filling port is opposite to the injection molding groove. When the lower plastic is prepared, molten plastic liquid can strike the groove surface of the injection molding groove when being injected into the molding cavity from the liquid filling port from top to bottom at high speed, and the molten plastic liquid can be scattered radially to the periphery at the moment, so that the molten plastic liquid is more uniformly and rapidly filled in the molding cavity, the molding efficiency and uniformity of the lower plastic are improved, and the production yield of the lower plastic is improved. After the molten plastic liquid fills the molding cavity and cools, dimples are formed on the first surface of the lower plastic. The depth of the dent is smaller than the height of the convex hull, so the convex hull can increase the structural strength of the lower plastic.

In addition, the diameter and the size of the liquid filling port at the top of the forming cavity of the die are matched with each other, the diameter of the convex hull is between 3.4 millimeters and 3.8 millimeters, and the corresponding size of the liquid filling port is between 3.4 millimeters and 3.8 millimeters, so that the flow speed of molten plastic liquid is higher, and the forming speed of lower plastic is further accelerated. In addition, when the molten plastic liquid flows faster, the depth of the final dent will be smaller, which is beneficial to increasing the flatness of the lower plastic and reducing the influence of the dent on the structural strength of the lower plastic.

Drawings

In order to more clearly illustrate the technical solution of the present application, the drawings that are required to be used in the embodiments will be briefly described.

Fig. 1 is an application scenario diagram of an energy storage device according to an embodiment of the present application.

Fig. 2 is a schematic perspective view of the energy storage device shown in fig. 1.

Fig. 3 is an exploded view of the energy storage device shown in fig. 2.

Fig. 4 is a schematic structural view of an end cap assembly of the energy storage device of fig. 3.

FIG. 5 is an exploded schematic view of the end cap assembly of FIG. 4.

Fig. 6 is a schematic view illustrating an assembly process of the energy storage device shown in fig. 2.

Fig. 7 is an exploded schematic view of the top cover of the end cap assembly shown in fig. 5.

Fig. 8 is a schematic view of another angle of the top cover body of the top cover shown in fig. 7.

FIG. 9 is a schematic view of the lower plastic of the end cap assembly of FIG. 5.

FIG. 10 is a schematic view of another angle of the lower plastic of FIG. 9.

Fig. 11 is a C-C cross-sectional view of fig. 9.

Fig. 12 is an enlarged view of D of fig. 11.

FIG. 13 is a schematic view of the lower plastic of FIG. 9 at another angle.

Fig. 14 is an enlarged view at a of fig. 9.

Fig. 15 is an enlarged view at B of fig. 10.

Fig. 16 is an enlarged view at C of fig. 11.

Fig. 17 is a schematic view of the cross-sectional structure A-A of fig. 4.

Fig. 18 is a schematic view of the cross-sectional structure of B-B of fig. 4.

Detailed Description

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

Because of the strong timeliness and space properties of energy required by people, in order to reasonably utilize the energy and improve the utilization rate of the energy, one energy form needs to be stored by one medium or equipment and then converted into another energy form, and the energy is released in a specific energy form based on future application. As is well known, to achieve the great goal of carbon neutralization, the main approach to green electric energy generation is to develop green energy sources such as photovoltaic, wind power and the like to replace fossil energy sources. At present, the generation of green electric energy generally depends on photovoltaic, wind power, water potential and the like, but wind energy, solar energy and the like generally have the problems of strong intermittence and large fluctuation, which can cause unstable power grid, insufficient peak electricity consumption, too much electricity consumption and unstable voltage can cause damage to the electric power, so that the problem of 'wind abandoning and light abandoning' possibly occurs due to insufficient electricity consumption requirement or insufficient power grid acceptance, and the problem needs to be solved by relying on energy storage. The energy is converted into other forms of energy through physical or chemical means and is stored, the energy is converted into electric energy when needed and released, in short, the energy storage is similar to a large-scale 'charge pal', the electric energy is stored when the photovoltaic and wind energy are sufficient, and the stored electric power is released when needed.

Taking electrochemical energy storage as an example, the scheme provides an energy storage device, wherein a group of chemical batteries are arranged in the energy storage device, chemical elements in the chemical batteries are mainly used as energy storage media, and the charge and discharge process is accompanied with chemical reaction or change of the energy storage media.

The existing energy storage (i.e. energy storage) application scene is wider, including aspects such as (wind and light) power generation side energy storage, electric network side energy storage, base station side energy storage and user side energy storage, the types of corresponding energy storage devices include:

(1) The large energy storage container applied to the energy storage scene at the power grid side can be used as a high-quality active and reactive power regulation power supply in the power grid, so that the load matching of electric energy in time and space is realized, the renewable energy consumption capability is enhanced, and the large energy storage container has great significance in the aspects of standby of a power grid system, relieving peak load power supply pressure and peak regulation and frequency modulation.

(2) The small and medium energy storage electric cabinet is applied to industrial and commercial energy storage scenes (banks, markets and the like) at the user side, and the main operation mode is peak clipping and valley filling. Because of the large price difference of the electricity charge at the peak-valley position according to the electricity consumption requirement, after the energy storage equipment is arranged by a user, in order to reduce the cost, the energy storage cabinet/box is charged usually in the electricity price valley period; and in the peak period of electricity price, the electricity in the energy storage equipment is released for use, so that the purpose of saving electricity charge is achieved.

Referring to fig. 1 and 2, an energy storage device provided by an embodiment of the present application is applied to an energy storage system, where the energy storage system includes an electric energy conversion device (photovoltaic panel 2000), a wind energy conversion device (fan 3000), a power grid 4000 and an energy storage device 1000, and the energy storage device 1000 can be used as an energy storage cabinet and can be installed outdoors. In particular, the photovoltaic panel 2000 may convert solar energy into electric energy during low electricity price period, and the energy storage device 1000 is used to store the electric energy and supply the electric power to the electric grid 4000 during peak electricity consumption or supply the electric power during power failure/power outage of the electric grid 4000. Wind energy conversion device (fan 3000) may convert wind energy into electrical energy, and energy storage device 1000 is used to store the electrical energy and supply electrical grid 4000 at peak power usage or at power outage/power failure of electrical grid 4000. The transmission of the electric energy can be performed by adopting a high-voltage cable.

The number of the energy storage devices 1000 may be several, and the several energy storage devices 1000 are connected in series or parallel, and the several energy storage devices 1000 are supported and electrically connected by using a separator (not shown). In this embodiment, "a plurality of" means two or more. An energy storage tank may be further disposed outside the energy storage device 1000, for accommodating the energy storage device 1000.

It is understood that the energy storage device 1000 may include, but is not limited to, a battery cell, a battery module, a battery pack, a battery system, etc. The practical application form of the energy storage device provided by the embodiment of the application can be, but is not limited to, the listed products, and can also be other application forms, and the embodiment of the application does not strictly limit the application form of the energy storage device 1000. The embodiment of the present application will be described by taking the energy storage device 1000 as a multi-core battery as an example.

The embodiment of the present application will be described by taking the energy storage device 1000 as a multi-core battery as an example.

Referring to fig. 2 and 3, the energy storage device 1000 includes an end cap assembly 100, an electrode assembly 200, a first separator 300, a second separator 310, a first adapter 400, a second adapter 410, and a case 500. The cap assembly 100 is mounted to one end of the electrode assembly 200, and the case 500 has an opening and is provided with a receiving chamber; the electrode assembly 200 is received in the receiving chamber, and the cap assembly 100 is sealed to the opening of the case 500. The first separator 300, the second separator 310, the first adapter 400, and the second adapter 410 are all connected between the end cap assembly 100 and the electrode assembly 200.

In this embodiment, the electrode assembly 200 includes two electrode cores 201. Along the width direction (Y-axis direction) of the energy storage device 1000, two pole pieces 201 are arranged side by side. Each of the tabs 201 includes a positive tab 202 and a negative tab 203. Along the width direction (X-axis direction) of the energy storage device 1000, the positive tabs 202 of the two electrode cores 201 are disposed respectively, and the negative tabs 203 of the two electrode cores 201 are disposed respectively. The positive tabs 202 of the two electrode cores 201 are connected with the positive electrode post 30 through the first adaptor 400, and the negative tabs 203 of the two electrode cores 201 are connected with the negative electrode post 40 through the second adaptor 410.

In this embodiment, the outside of the electrode assembly 200 is further covered with an insulating film (not shown) for protecting the electrode core 201 from being scratched. The insulating film is coated on the outer surface of the electrode assembly 200, and the side edges of the insulating film are thermally fusion-bonded with the cap assembly 100.

In this embodiment, referring to fig. 3, the first adaptor 400 is a generally "コ" conductive sheet, and includes a first body 401, a first adaptor 402 and a second adaptor 403, wherein the first adaptor 402 and the second adaptor 403 are rectangular sheets, each of which extends parallel to the first body 401 on one side of the first body 401, and the first adaptor 402 and the second adaptor 403 are disposed at intervals and have the same extending direction. The first body 401 is used for connection with the positive electrode tab 30. The first adapter 402 and the second adapter 403 are used for connecting the positive tabs 202 of the two pole cores 201.

The second adaptor 410 is a substantially "ㄈ" conductive sheet, and includes a second body 411, a third adaptor 412 and a fourth adaptor 413, wherein the third adaptor 412 and the fourth adaptor 413 extend from one side of the second body 411 parallel to the second body 411, and the third adaptor 412 and the fourth adaptor 413 are disposed at intervals and have the same extending direction. The second body 411 is for connection with the negative electrode post 40. The third adapter 412 and the fourth adapter 413 are connected to the negative tab 203 of the two electrode cores 201.

For convenience of description, the length direction of the end cap assembly 100 shown in fig. 2 is defined as an X-axis direction, the width direction of the end cap assembly 100 is defined as a Y-axis direction, the thickness direction of the end cap assembly 100 is defined as a Z-axis direction, and the X-axis direction, the Y-axis direction and the Z-axis direction are perpendicular to each other. The terms of "upper", "top", "lower", "bottom", "left", "right", and the like in the description of the embodiments of the present application are described according to the directions shown in fig. 2 of the specification, and are not limited to the energy storage device 1000 in the practical application scenario. The use of "identical", "equal" or "parallel" in the following allows for certain tolerances.

Referring to fig. 4 and 5 together, the end cap assembly 100 includes a lower plastic 10, a top cap 20, a positive electrode post 30, a negative electrode post 40, a first upper plastic 50 and a second upper plastic 51. The top cover 20 in this embodiment is an aluminum part, and the lower plastic 10 is made of plastic material and is insulated. Specifically, the first upper plastic 50 and the second upper plastic 51 are fixedly connected with the top cover 20 respectively, the first upper plastic 50 is sleeved on the positive pole post 30, the second upper plastic sleeve 51 is arranged on the negative pole post 40, the positive pole post 30 is insulated from the top cover 20 through the first upper plastic 50, and the negative pole post 40 is insulated from the top cover 20 through the second upper plastic 51. The positive electrode post 30 is provided with a positive electrode flange 31, and the negative electrode post 40 is provided with a negative electrode flange 41. The positive flange 31 is used for electrical connection with the first adapter 400, and the negative flange 41 is used for electrical connection with the second adapter 410.

Referring also to fig. 6, in the present embodiment, the lower plastic 10 is mounted on the top cover 20, and the lower plastic 10 is located between the electrode assembly 200 and the top cover 20. The first adaptor 400 and the second adaptor 410 are connected to the lower surface of the lower plastic 10 at opposite intervals, the first adaptor 400 is connected to the positive tab 202 of the electrode assembly 200 and the positive post 30 of the end cap assembly 100, and the second adaptor 410 is connected to the negative tab 203 of the electrode assembly 200 and the negative post 40 of the end cap assembly 100. The first separator 300 covers the positive electrode tab 202 of the electrode assembly 200, and the second separator 310 covers the negative electrode tab 203 of the electrode assembly 200.

Specifically, the first body 401 of the first adaptor 400 is welded to the positive flange 31 of the positive electrode post 30, and the first adaptor 402 and the second adaptor 403 are welded to the positive tabs 202 of the two electrode cores 201. The second body 411 of the second adaptor 410 is welded and fixed to the negative flange 41 of the negative electrode post 40, and the third adaptor 412 and the fourth adaptor 413 are welded and fixed to the negative tabs 203 of the two electrode cores 201.

After the positive electrode tab 202 is welded to the first adapter 400, the first separator 300 covers the positive electrode tab 202 (the portion welded to the first adapter 400 and the portion located on the electrode core 201). After the negative electrode tab 203 is welded to the second adapter 410, the second separator 310 covers the negative electrode tab 203 (the portion welded to the second adapter 410 and the portion located on the electrode core 201).

Referring to fig. 7, in the present embodiment, the cap 20 includes a cap body 21, an explosion-proof valve 22, and a sealing plug 23. The cap body 21 is provided with a positive electrode through hole 211, a negative electrode through hole 212, a liquid injection hole 213, a first mounting groove 214, a second mounting groove 215, a through groove 216 and a liquid injection groove 217. The positive electrode through hole 211, the liquid injection hole 213, the through groove 216 and the negative electrode through hole 212 are sequentially arranged at intervals along the X-axis direction, that is, the length direction of the top cover body 21.

Specifically, referring to fig. 8, the top cover body 21 is an elongated thin plate, and includes a first mounting surface 218 and a second mounting surface 219 opposite to the first mounting surface 218. The first mounting groove 214 and the second mounting groove 215 are located at opposite end positions (aligned along the X-axis direction) of the second mounting surface 219 of the top cover body 21. The first mounting groove 214 and the second mounting groove 215 are rectangular grooves, the first mounting groove 214 is formed by the second mounting surface 219 being recessed toward the first mounting surface 218, and the second mounting groove 215 is formed by the second mounting surface 219 being recessed toward the first mounting surface 218. The positive electrode through hole 211 penetrates the first mounting surface 218 and the bottom wall of the first mounting groove 214, and the negative electrode through hole 212 penetrates the first mounting surface 218 and the bottom wall of the second mounting groove 215. It will be appreciated that the positive through hole 211 and the negative through hole 212 are respectively provided at opposite ends of the top cover body 21 for passing the positive electrode post 30 and the negative electrode post 40 of the battery, respectively. The first mounting groove 214 and the second mounting groove 215 are respectively used for accommodating a part of the lower plastic 10.

The liquid filling hole 213 is provided between the first mounting groove 214 and the explosion-proof valve 22, and in the liquid filling process of the power battery, the electrolyte is filled into the battery through the liquid filling hole 213 in the top cover 20. The sealing plug 23 is fitted into the liquid filling hole 213 by the first mounting surface 218 and seals the liquid filling hole 213.

The through groove 216 is located at a middle position of the top cover body 21, the through groove 216 penetrates through the second mounting surface 219 and the first mounting surface 218, and the through groove 216 is located between the first mounting groove 214 and the second mounting groove 215. The explosion proof valve 22 is received in the through groove and welded with the groove wall of the through groove 216. When the pressure in the energy storage device 1000 is too high, the explosion-proof valve 22 will automatically open to release pressure, so as to prevent explosion.

The liquid injection groove 217 is concavely arranged on the first mounting surface 218, and the second mounting surface 219 is provided with a convex part 220; the protrusion 220 is formed by recessing the liquid injection groove 217 into the first mounting surface 218 and protrudes from the second mounting surface 219; along the thickness direction of the top cover 20; the filling hole 213 penetrates the bottom plate of the filling tank 217 and the projection 220. Wherein the liquid injection groove 217 is a circular groove.

Referring to fig. 7 and 8, the sealing plug 23 comprises a cover 231 and a plug 232, the cover 231 being adapted to the liquid filling slot 217, in this embodiment a circular rubber plug. The plug 232 is a columnar body protruding from one surface of the cover 231, and the cover 231 and the plug 232 are actually integrally formed. Wherein, the end surface of the plug 232 far away from the cover 231 is a plane. The cover 231 is accommodated in and sealed with the liquid filling tank 217, the plug 232 penetrates through the liquid filling hole 213, and is partially positioned in the liquid filling hole 213, and the part of the protruding part 220 is exposed out of the second mounting surface 219. In other embodiments, the sump 217 and the protrusion 220 may be omitted, with the sump 217 extending directly through the second mounting surface 219 and the first mounting surface 218.

In this embodiment, referring to fig. 4 and 9, the lower plastic 10 is laminated with the top cover 20, the length of the lower plastic 10 is the same as the length of the top cover 20, and the width of the lower plastic 10 is equal to the width of the top cover 20, wherein a certain tolerance range is allowed. In this embodiment, the lower plastic 10 is an integrally formed component.

In this embodiment, referring to fig. 10 together, the lower plastic 10 is a substantially rectangular sheet and includes a first surface 111 and a second surface 112, and the first surface 111 and the second surface 112 are opposite to each other along the Z-axis direction.

In this embodiment, the lower plastic 10 is provided with a first groove 101, a first post through hole 102, a second groove 103, and a second post through hole 104. The first post through hole 102 is used for passing the positive post 30. The first groove 101 is configured to receive the positive flange 31 of the positive post 30 of the energy storage device 1000. The first groove 101 is surrounded by a first convex ring 12 protruding from the second surface 112, and forms a first clamping protrusion 13 on the first surface 111. In this embodiment, the depth of the first groove 101 is the same as the thickness of the positive electrode flange 31, so that when the positive electrode flange 31 is mounted in the first groove 101, the surface facing away from the positive electrode post 30 is flush with the second surface 112. The first post through hole 102 is a circular through hole, and the first post through hole 102 penetrates the first surface 111 and the bottom wall of the first groove 101, that is, the first holding protrusion 13. The first post through hole 102 is near the end of the lower plastic 10.

The second post through hole 104 is used for the negative post 40 to pass through. The second groove 103 is configured to receive the negative flange 41 of the negative pole 40 of the energy storage device 1000. The second groove 103 is surrounded by a second convex ring 14 protruding from the second surface 112, and forms a second clamping protrusion 15 on the first surface 111. The second post through hole 104 is a circular through hole, and the second post through hole 104 penetrates through the first surface 111 and the bottom wall of the second groove 103, that is, penetrates through the second holding protrusion 15. The second post via 104 is near the end of the lower plastic 10.

Referring to fig. 9 and 10, the lower plastic 10 further includes the injection through hole 105 and the protection cover 16, the injection through hole 105 penetrates through the first surface 111 and the second surface 112, the injection through hole 105 is located at one end of the lower plastic 10, and is spaced from the first post through hole 102 along the length direction of the lower plastic 10. The liquid injection through hole 105 communicates with the liquid injection hole for passage of the electrolyte. The boot 16 is adapted to cover the plug body 232 of the sealing plug 23. In this embodiment, the protection cover 16 and the lower plastic 10 are integrally formed in a mold, and a slit 161 is formed on the protection cover 16, and the slit 161 is used for allowing liquid to flow through.

Referring to fig. 10, the lower plastic 10 further includes two reinforcing protrusions 17, the reinforcing protrusions 17 are protruded at two edges of the second surface 112 in the width direction, and the injection through hole 105 and the protection cover 16 are located between the two reinforcing protrusions 17. The reinforcing protrusions 17 enhance the structural strength of the lower plastic 10 in the length direction.

With continued reference to fig. 10, the lower plastic 10 further includes a first rib 18 and a second rib 19, the first rib 18 and the second rib 19 protruding from two edges of the second surface 112 in the length direction. The first rib 18 is adjacent to the first post through hole 102 and the second rib 19 is adjacent to the second post through hole 104. The first rib 18 is provided with a plurality of through holes for the passage of the electrolyte. The second rib 19 is provided with a plurality of through holes for the passage of the electrolyte. The first rib 18 and the second rib 19 can strengthen the end of the lower plastic 10, and prevent the end from tilting and deforming.

With continued reference to fig. 9 and 10, the lower plastic 10 further includes an indent 10A and a convex hull 10B, the indent 10A being located on the first surface 111, the convex hull 10B being convex on the second surface 112. Referring to fig. 11 and 12, the orthographic projection of the convex hull 10B on the first surface 111 completely covers the dimple 10A.

Referring to fig. 11 and 12, in the present embodiment, the convex hull 10B is hemispherical. The diameter phi of the convex hull 10B is between 3.4 mm and 3.8 mm. Specifically, the value of phi may be 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm or 3.8 mm.

Referring to fig. 13, convex hull 10B is centered along the X-axis on second surface 112. Specifically, second surface 112 includes a first edge 112a and a second edge 112B that are opposite in the X-axis direction, and the distance from convex hull 10B to first edge 112a is the same as the distance from convex hull 10B to second edge 112B.

The mold for preparing the lower plastic 10 is provided with a molding cavity, the top of the molding cavity is provided with a liquid filling port, the bottom of the molding cavity is concavely provided with an injection molding groove, the shape of the injection molding groove is matched with that of the convex hull 10B, and the liquid filling port is opposite to the injection molding groove. When the lower plastic 10 is prepared, molten plastic liquid can strike the groove surface of the injection molding groove when being injected into the molding cavity from the liquid filling port from top to bottom at high speed, and the molten plastic liquid can be scattered radially to the periphery at the moment, so that the molten plastic liquid is more uniformly and rapidly filled in the molding cavity, the molding efficiency and uniformity of the lower plastic are improved, and the production yield of the lower plastic is improved. After the molten plastic liquid fills the molding cavity and cools, after the plastic column remaining in the filling port and being fixed with the first surface 111 of the lower plastic 10 is removed, an indent 10A is formed on the first surface 111 of the lower plastic 10, and the indent 10A is recessed relative to the first surface 111.

Convex hull 10B is centered along the X-axis on second surface 112. Correspondingly, the liquid filling port is positioned in the middle of the X axis direction of the forming cavity of the die, so that when molten plastic liquid is poured into the forming cavity, the efficiency of flowing to two opposite side surfaces of the forming cavity along the X axis direction is approximately the same, and the lower plastic 10 is formed more uniformly.

The convex hull 10B is further arranged so that when molten plastic liquid is cooled and molded, the cooling speeds of the concave pit 10A and the convex hull 10B are consistent, the risk of water shrinkage at the convex hull 10B is reduced, and the flatness of the first surface 111 is ensured to be good.

Convex hull 10B is provided as a hemispherical shape. The groove surface of the corresponding injection molding groove is a concave arc surface, so that molten plastic liquid can radiate more uniformly around.

In addition, the convex hull 10B can increase the structural strength of the lower plastic 10, so that the structure of the lower plastic 10 is more stable, and the lower plastic 10 is easy to process and has lower cost.

It can be understood that the diameter and the size of the liquid filling port at the top of the molding cavity of the mold are adapted to each other, and the diameter of the convex hull 10B is between 3.4 mm and 3.8 mm, so that the corresponding size of the liquid filling port is between 3.4 mm and 3.8 mm, so that the flow velocity of molten plastic liquid is faster, and the molding speed of lower plastic is further increased. In addition, when the flow rate of the molten plastic is faster, the depth of the final dent 10A is smaller, which is beneficial to increasing the flatness of the lower plastic and reducing the influence of the dent on the structural strength of the lower plastic.

Referring to fig. 9 and 10, in the present embodiment, the dimple 10A includes a first dimple 108 and a second dimple 109, and the convex hull 10B includes a first convex hull 106 and a second convex hull 107. The orthographic projection of the first convex hull 106 on the first surface 111 completely covers the first dimple 108 and the orthographic projection of the second convex hull 107 on the first surface 111 completely covers the second dimple 109. Correspondingly, the liquid filling port of the mold for preparing the lower plastic 10 comprises a first liquid filling port and a second liquid filling port, the injection molding groove comprises a first injection molding groove and a second injection molding groove, the first liquid filling port is opposite to the first injection molding groove, and the second liquid filling port is opposite to the second injection molding groove. The two convex hulls and the two dents are arranged, so that the injection uniformity and the injection efficiency can be improved.

Referring to fig. 13, in the present embodiment, the second surface 112 further includes a third edge 112c and a fourth edge 112d opposite in the X-axis direction. The third edge 112c, the first convex hull 106, the second convex hull 107, and the fourth edge 112d are sequentially arranged along the Y-axis direction. The distance between the third edge 112c and the first convex hull 106 is a first distance LA1, the distance between the first convex hull 106 and the second convex hull 107 is a second distance LA2, and the distance between the second convex hull 107 and the fourth edge 112d is a third distance LA3. Wherein, la1=la2=la3. Therefore, when molten plastic liquid is poured into the forming cavity, the efficiency of flowing to two opposite side surfaces of the forming cavity along the Y-axis direction is approximately the same, so that the lower plastic 10 is formed more uniformly.

With continued reference to fig. 9 and 10, the lower plastic 10 is provided with an explosion-proof barrier 120, the explosion-proof barrier 120 being disposed between the first rib 18 and the second rib 19, the explosion-proof barrier 120 being recessed from the first surface 111 toward the second surface 112 and protruding relative to the second surface 112. The explosion-proof fence 120 has a rectangular frame shape with one side opened, and the explosion-proof fence 120 includes a concave chamber 121 communicating with the opening thereof. The opening of the explosion proof barrier 120 passes through the first surface 111 of the lower plastic 10.

In the present embodiment, referring to fig. 14 and 15, the explosion-proof fence 120 is provided with a plurality of through holes 122. Since the tab or the blue film is easily broken to generate fragments during transportation and use of the energy storage device 1000. The explosion-proof fence 120 can prevent fragments of the tab or the blue film from floating below the explosion-proof valve 22, avoid shielding an air passage, further avoid causing explosion failure, prevent the tab from drifting to the explosion-proof valve 22 and avoid shorting the electrically connected electrode and the top cover 20.

Referring to fig. 14 and 15, the explosion-proof fence 120 includes an explosion-proof bottom plate 130 and an explosion-proof peripheral plate 140, the explosion-proof bottom plate 130 is in a rectangular sheet shape, the explosion-proof peripheral plate 140 is in a rectangular ring shape, the explosion-proof peripheral plate 140 is circumferentially connected to the outer periphery of the explosion-proof bottom plate 130, and the opening of the explosion-proof bottom plate 130 and the opening of the explosion-proof fence are opposite along the Z-axis direction. An explosion-proof bottom plate 130 and an explosion-proof peripheral plate 140 enclose a recessed chamber 121. The explosion-proof peripheral plate 140 includes first and second side plates 141 and 142 opposite in the X-axis direction, and first and second end plates 143 and 144 opposite in the Y-axis direction. The first side plate 141, the first end plate 143, the second side plate 142, and the second end plate 144 are connected end to end in sequence.

Referring to fig. 14 and 15, the explosion-proof bottom plate 130 includes an inner surface 131 and an outer surface 132 disposed opposite to each other in a thickness direction thereof. The through-hole 122 is located on the explosion-proof floor 130, and the through-hole 122 penetrates through the inner surface 131 and the outer surface 132.

The first side plate 141 includes a first inner side surface 150 and a first outer side surface 151 disposed opposite to each other in the thickness direction thereof, and the second side plate 142 includes a second inner side surface 152 and a second outer side surface 153 disposed opposite to each other in the thickness direction thereof. The first end plate 143 includes a first inner end surface 154 and a first outer end surface 155 disposed opposite to each other in the thickness direction thereof, and the second end plate 144 includes a second inner end surface 156 and a second outer end surface 157 disposed opposite to each other in the thickness direction thereof. The first inner side 150, the second inner side 152, the first inner end 154, and the second inner end 156 are cavity sides of the recessed cavity 121, and the inner surface 131 is a cavity bottom of the recessed cavity 121.

Referring to fig. 15, one side of the outer surface 132 and the first outer side 151 are connected by a first circular arc surface 158, and the other side of the outer surface 132 and the second outer side 153 are connected by a second circular arc surface 159. In this embodiment, the outer surface 132 and the first outer side surface 151 are connected by a first circular arc surface 158, and the second outer surface and the second outer side surface 153 are connected by a second circular arc surface 159. The two sides of the bottom of the explosion-proof molding cavity are correspondingly provided with a first concave cambered surface and a second concave cambered surface. When molten plastic liquid is injected into the forming cavity from the liquid filling port at a high speed, the molten plastic liquid can smoothly flow to the bottom filled with the explosion-proof forming cavity along the first concave cambered surface and the second concave cambered surface, so that the molten plastic is prevented from being accumulated, and the structural strength and the product yield of the explosion-proof fence are further improved.

The lower plastic 10 is provided with a first notch 113 and a second notch 114, wherein the first notch 113 is concavely arranged on the first surface 111 and penetrates through the first side plate 141 along the length direction of the lower plastic 10; the second notch 114 is concavely disposed on the first surface 111, and penetrates the second side plate 142 along the length direction of the lower plastic 10. The first notch 113 can release the stress at the connection between the first side plate 141 and the first surface 111 and the second surface 112, and the second notch 114 can release the stress at the connection between the second side plate 142 and the first surface 111 and the second surface 112, so that the structure of the lower plastic 10 is stable.

Referring to fig. 16, the first side plate 141 and the second side plate 142 are inclined with respect to the Z-axis direction, and the inclination directions of the first side plate 141 and the second side plate 142 are opposite. The first side plate 141 and the second side plate 142 gradually approach each other from the positive direction of the Z axis to the negative direction of the Z axis. The first side plate 141 has an inclination angle a ranging from 2 ° to 15 °, and the included angle a may specifically take the values of 2 °, 3 °, 4 °, 5 °, 6 °, 7 °, 9 °, 11 °, 12 °, 13 °, 14 °, 15 °, and so on. The inclination angle b of the second side plate 142 is between 2 degrees and 15 degrees, and the included angle b may specifically take the values of 2 °, 3 °, 4 °, 5 °, 6 °, 7 °, 9 °, 11 °, 12 °, 13 °, 14 ° or 15 °.

When the lower plastic 10 is injection molded, an explosion-proof molding cavity is concavely arranged at the bottom of the molding cavity of the injection mold and is used for molding the explosion-proof fence. The first side plate 141 and the second side plate 142 are each inclined with respect to the Z-axis direction. When the lower plastic 10 is injection molded, the two side plates of the explosion-proof molding cavity are also obliquely arranged, and the oblique directions are opposite, so that when molten plastic liquid is injected into the molding cavity from the liquid filling port at a high speed, the molten plastic liquid flows along the two side plates of the explosion-proof molding cavity, the molten plastic liquid can be prevented from vertically flowing to strike the side surfaces of the explosion-proof molding cavity, further, the strength of the corners of the first side plate 141 and the second side plate 142 is prevented from being reduced, and the structural strength of the corners of the first side plate 141 and the second side plate 142 can be ensured.

In addition, in the case where the height dimension of the first and second side plates 141 and 142 in the Z-axis direction is not changed, the areas of the first and second inner side surfaces 150 and 151 and the areas of the second and outer side surfaces 152 and 153 may be increased as compared to the case where the first and second side plates 141 and 142 are disposed parallel to the Z-axis direction to be inclined with respect to the Z-axis direction. Accordingly, when the vibration of the energy storage device 1000 causes the electrode assembly 200 to strike the explosion-proof fence 120, the stress at the first and second side plates 141 and 142 is dispersed, so that the explosion-proof fence 120 is prevented from being irreversibly deformed.

Referring to fig. 14, a reinforcing rib 160 is provided inside the concave chamber 121, and the reinforcing rib 160 is shaped like an "h". The ribs 160 are raised relative to the inner surface 131 and are connected to the first inner side 150 and the second inner side 152. The plurality of through holes 122 are offset from the stiffener 160, i.e., the stiffener 160 does not block the through holes 122.

Referring to fig. 16, the thickness dimension of the reinforcing rib 160 is gradually reduced in the Z-axis direction, and the thickness dimension of the bottom of the reinforcing rib 160 is larger than the dimension of the top of the reinforcing rib 160, that is, the thickness dimension of the side of the reinforcing rib 160 connected to the inner surface 131 is larger than the dimension of the side facing away from the inner surface 131. In other words, the cross section of the reinforcing rib 160 in the Z-axis direction is trapezoidal. Specifically, the thickness dimension H1 of the bottom of the reinforcing rib 160 is between 1.7 mm and 2.0 mm, and H1 may specifically take a value of 1.7 mm, 1.75 mm, 1.8 mm, 1.85 mm, 1.9 mm, 1.95 mm, or 2.0 mm. The thickness dimension H2 of the top of the rib 160 is between 1.3 mm and 1.55 mm, and H2 may specifically take the value of 1.3 mm, 1.33 mm, 1.36 mm, 1.39 mm, 1.42 mm, 1.45 mm, 1.48 mm, 1.51 mm, 1.53 mm, or 1.55 mm.

The reinforcing bars 160 may improve the structural strength of the explosion-proof fence 120. The thickness of the bottom of the reinforcing rib 160 is larger than that of the top, so that the connection strength of the reinforcing rib 160 and the explosion-proof fence can be improved, the formation of a water shrinkage groove at the bottom of the reinforcing rib 160 during lower plastic injection molding can be avoided, and the flatness and the structural strength of the cavity bottom surface of the concave cavity 121 can be improved.

Referring to fig. 14 and 16, the reinforcing rib 160 includes a first reinforcing plate 170, a second reinforcing plate 180 and a third reinforcing plate 190, the first reinforcing plate 170 and the second reinforcing plate 180 each extend in the X-axis direction, the first reinforcing plate 170 and the second reinforcing plate 180 are spaced apart in the Y-axis direction, opposite ends of the first reinforcing plate 170 are respectively fixed to the first inner side surface 150 and the second inner side surface 152, one side of the first reinforcing plate 170 is fixed to the inner surface 131, the first reinforcing plate 170 includes a first connection surface 171 facing away from the inner surface 131, and the first connection surface 171 is flush with the first surface 111. Opposite ends of the second reinforcing plate 180 are respectively fixed to the first inner side surface 150 and the second inner side surface 152, one side of the second reinforcing plate 180 is fixed to the inner surface 131, the second reinforcing plate 180 includes a second connecting surface 181 facing away from the inner surface 131, and the second connecting surface 181 is flush with the first surface 111.

The third reinforcing plate 190 extends in the Y-axis direction, and opposite ends of the third reinforcing plate 190 are fixed to the first reinforcing plate 170 and the second reinforcing plate 180, respectively. One side of the third reinforcing plate 190 is fixed to the inner surface 131, the third reinforcing plate 190 includes a third connecting surface 191 facing away from the inner surface 131, the third connecting surface 191 is lower than the first surface 111, and a height difference H3 between the third connecting surface 191 and the first surface 111 is between 0.45 mm and 2.25 mm, and the H3 may be specifically 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.75 mm, 0.85 mm, 0.95 mm, 1 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2.1 mm, 2.2 mm, 2.23 mm, 2.25 mm, or the like.

Referring to fig. 17, the lower plastic 10 is attached to the second mounting surface 219 of the top cover body 21 of the top cover 20, and the first surface 111 of the lower plastic 10 is opposite to and attached to the second mounting surface 219 of the top cover 20.

The explosion-proof barrier 120 of the lower plastic 10 is disposed opposite to the explosion-proof valve 22 of the top cover 20. The top of the first reinforcing plate 170 (i.e., the first connection surface 171) and the top of the second reinforcing plate 180 (i.e., the second connection surface 181) are abutted against the second installation surface 219 of the top cover 20, so that the supporting force of the explosion-proof fence 120 on the top cover 20 can be enhanced. A gap J is formed between the top of the third reinforcing plate 190 (i.e., the third connecting surface 191) and the explosion-proof valve 22, and the width of the gap J is the same as H3, i.e., the height difference H3 between the third connecting surface 191 and the first surface 111 is the gap J. When the energy storage device 1000 accidentally falls down during transportation and use to cause the pole core 201 to strike the explosion-proof fence 120 of the plastic 10, the existence of the gap J can prevent the third reinforcing plate 190 from extruding the explosion-proof valve 22, so that the explosion-proof valve 22 is prevented from being accidentally opened, and the safety performance of the energy storage device 1000 is improved.

In the X-axis direction, the distance L1 between the weld mark on the left side edge of the explosion-proof valve 22 and the first reinforcing plate 170 is greater than 4 mm, and L1 may specifically take values of 4 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, and so on. The distance L2 between the weld mark on the right side edge of the explosion-proof valve 22 and the second reinforcing plate 180 is greater than 4 mm, and the value of L2 may be specifically 4 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, or the like. Thus, the first reinforcing plate 170 and the second reinforcing plate 180 are prevented from being pushed against the explosion-proof valve 22, the explosion-proof valve 22 is prevented from being pressed, the explosion-proof valve 22 is prevented from being opened accidentally, and the safety performance of the energy storage device 1000 is improved.

Referring to fig. 18, the first catching protrusion 13 is inserted into the first mounting groove 214; wherein, the first clamping protrusion 13 and the first mounting groove 214 can be mutually clamped to realize mutual positioning. Along the thickness direction (Z-axis direction) of the top cover 20, the first post through hole 102 of the lower plastic 10 is disposed opposite to and communicates with the positive through hole 211 of the top cover 20.

The positive electrode post 30 passes through the first electrode post through hole 102 and the positive electrode through hole 211, the positive electrode flange 31 is accommodated in the first groove 101 and fixedly connected with the positive electrode post 30, and the surface of the positive electrode flange 31 facing away from the positive electrode post 30 is flush with the second surface 112. The positive flange 31 is flush with the surface of the first collar 12.

The second catching protrusion 15 is inserted into the second mounting groove 215; wherein, the second clamping protrusion 15 and the second mounting groove 215 can be mutually clamped to realize mutual positioning. The second post through hole 104 of the lower plastic 10 is disposed opposite to and communicates with the negative electrode through hole 212 of the top cover 20 in the thickness direction (Z-axis direction) of the top cover 20.

The negative electrode post 40 passes through the second post through hole 104 and the negative electrode through hole 212, the negative electrode flange 41 is accommodated in the second groove 103 and fixedly connected with the negative electrode post 40, and the surface of the negative electrode flange 41 facing away from the negative electrode post 40 is flush with the surface of the second convex ring 14.

The liquid injection through holes 105 of the lower plastic 10 are opposite to and communicated with the liquid injection holes 213 of the top cover 20, and the protective cover 16 is opposite to the top cover 20; the cover 231 is accommodated in and sealed to the liquid filling tank 217, the sealing plug 23 is mounted in the liquid filling hole 213, the plug 232 passes through the liquid filling hole 213 and the liquid filling through hole 105 and extends into the space of the protective cover 16, and a gap is formed between the free end of the plug 232 and the protective cover 16. The protection cover 16 can prevent the pole core 201 from extruding the plug body 232 to cause the top cover 20 of the liquid injection hole 213 to crack; on the other hand, the protective cover 16 can avoid the active material on the positive electrode lug 202 from falling off due to the impact of the electrolyte on the electrode core 201 when the electrolyte is injected, and avoid the internal short circuit of the battery caused by the reverse insertion of the positive electrode lug 202; the gap 161 of the protective cover 16 is used for shunting electrolyte in the space of the protective cover 16, and the electrolyte flows out through the gap 161, so that the uniformity of the injected electrolyte is improved.

The foregoing has outlined rather broadly the more detailed description of embodiments of the application in order that the detailed description of the principles and embodiments of the application may be implemented in conjunction with the detailed description of embodiments of the application that follows.

Claims

1. A lower plastic, characterized in that the lower plastic comprises a first surface and a second surface, and the first surface and the second surface are arranged opposite to each other along the thickness direction of the lower plastic; the first surface is provided with an indent, and the second surface is convexly provided with a convex hull; an orthographic projection of the convex hull on the first surface completely covers the dimple.

2. The lower plastic of claim 1, wherein the convex hull is hemispherical.

3. The lower plastic of claim 2, wherein the convex hull has a diameter between 3.4 mm and 3.8 mm.

4. The lower plastic of claim 1, wherein the second surface comprises a first edge and a second edge, the first edge and the second edge being opposite along a length of the lower plastic, the distance from the convex hull to the first edge being the same as the distance from the convex hull to the second edge.

5. The lower plastic of claim 1, wherein the number of the indentations is two, the number of the convex hulls is two, and the number of the convex hulls is two, and the number of the convex hulls is two;

orthographic projection of the first convex hull on the first surface completely covers the first indent; orthographic projection of the second convex hull on the first surface completely covers the second indent; the first convex hull and the second convex hull are arranged at intervals along the length direction of the lower plastic.

6. The lower plastic of claim 5, wherein the first surface further comprises a third edge and a fourth edge, the third edge and the fourth edge are opposite along the length direction of the lower plastic, and the third edge, the first convex hull, the second convex hull, and the fourth edge are sequentially arranged along the length direction of the lower plastic;

in the length direction of the lower plastic, the distance between the third edge and the first convex hull is a first distance, the distance between the first convex hull and the second convex hull is a second distance, the distance between the second convex hull and the fourth edge is a third distance, and the first distance, the second distance and the third distance are the same.

7. The lower plastic according to any one of claims 1 to 6, wherein the lower plastic is further provided with an explosion-proof barrier, which is recessed from the first surface toward the second surface and is raised with respect to the second surface; the explosion-proof fence is provided with a concave cavity penetrating through the first surface;

the explosion-proof fence comprises an explosion-proof bottom plate, the explosion-proof bottom plate and the second surface are arranged at intervals along the thickness direction of the lower plastic, and the explosion-proof bottom plate is provided with through holes.

8. The lower plastic of claim 7, wherein the explosion-proof barrier further comprises a first side plate and a second side plate, the first side plate and the second side plate are opposite along the length direction of the lower plastic, and the first side plate and the second side plate are respectively connected with two sides of the explosion-proof bottom plate along the length direction of the lower plastic;

the first side plate and the second side plate are inclined relative to the thickness direction of the lower plastic, and the inclination directions of the first side plate and the second side plate are opposite; the first side plate and the second side plate are gradually close to each other in a direction pointing to the explosion-proof bottom plate from the second surface.

9. The lower plastic of claim 8, wherein the junction of the first side panel and the explosion proof bottom panel facing away from the recessed cavity transitions with a first arcuate surface;

the second side plate and the explosion-proof bottom plate are in transition with a second arc surface at the joint of the concave cavity.

10. The lower plastic of claim 8, wherein the lower plastic is provided with a first notch and a second notch, the first notch is concavely arranged on the first surface and penetrates through the first side plate along the length direction of the lower plastic; the second notch is concavely arranged on the first surface and penetrates through the second side plate along the length direction of the lower plastic.

11. The lower plastic of claim 8, wherein a stiffener is disposed in the recessed cavity, the stiffener is vertically fixed to the explosion-proof bottom plate, and the stiffener is fixed to the first side plate and the second side plate.

12. The lower plastic according to claim 11, wherein the thickness dimension of the reinforcing ribs is gradually reduced in the thickness direction of the lower plastic, and the thickness of the bottom of the reinforcing ribs is greater than the thickness dimension of the top of the reinforcing ribs.

13. The lower plastic of claim 11, wherein the stiffener comprises a first stiffener and a second stiffener; the first reinforcing plates and the second reinforcing plates are arranged at intervals along the width direction of the lower plastic; the first reinforcing plate and the second reinforcing plate extend along the length direction of the lower plastic, and the opposite ends of the first reinforcing plate and the second reinforcing plate are connected with the first side plate and the second side plate.

14. The lower plastic of claim 13, wherein the reinforcing ribs further comprise a third reinforcing plate extending in a width direction of the lower plastic, and opposite ends of the third reinforcing plate are respectively fixed to the first reinforcing plate and the second reinforcing plate.

15. The lower plastic of claim 13, wherein the top of the first reinforcement plate is flush with the first surface and the top of the second reinforcement plate is flush with the first surface.

16. The lower plastic of claim 14, wherein the top of the third reinforcement panel is lower than the top of the first reinforcement panel.

17. An end cap assembly, comprising: the lower plastic of any one of claims 1 to 6, and a top cover; the lower plastic cement is arranged on the surface of the top cover, and the first surface is abutted against the top cover.

18. The end cap assembly of claim 17, wherein the lower plastic body is further provided with an explosion-proof barrier recessed from the first surface toward the second surface and raised relative to the second surface; the explosion-proof fence is provided with a concave cavity penetrating through the first surface;

a first reinforcing plate and a second reinforcing plate are arranged in the concave cavity; the top of the first reinforcing plate is flush with the first surface, and the top of the first reinforcing plate is abutted with the top cover; the top of the second reinforcing plate is flush with the first surface, and the top of the second reinforcing plate is abutted with the top cover.

19. The end cap assembly of claim 18, wherein a third reinforcing plate is further disposed within the recessed cavity, the top of the third reinforcing plate being lower than the top of the first reinforcing plate, the top cap being connected to an explosion proof valve; the third reinforcing plate faces the explosion-proof valve, and a gap is reserved between the top of the third reinforcing plate and the explosion-proof valve.

20. The end cap assembly of claim 19, wherein the explosion proof valve is located between the first reinforcement panel and the second reinforcement panel in a width direction of the lower plastic, and wherein a weld mark of the explosion proof valve is spaced from the first reinforcement panel; and a space is reserved between the welding mark of the explosion-proof valve and the second reinforcing plate.

21. An energy storage device comprising a housing, an electrode assembly and an end cap assembly as claimed in any one of claims 17 to 20, the housing having an opening, the housing being provided with a receiving cavity, the electrode assembly being received in the receiving cavity, the end cap assembly covering the opening.

22. A powered device comprising the energy storage device of claim 21, the energy storage device configured to store electrical energy.