CN116365130A

CN116365130A - End cover assembly, energy storage device and household energy storage system

Info

Publication number: CN116365130A
Application number: CN202310484333.5A
Authority: CN
Inventors: 熊永锋; 陈志雄; 洪纯省
Original assignee: Xiamen Hithium Energy Storage Technology Co Ltd
Current assignee: Xiamen Hithium Energy Storage Technology Co Ltd
Priority date: 2023-04-28
Filing date: 2023-04-28
Publication date: 2023-06-30

Abstract

The application provides an end cover subassembly, energy memory and domestic energy storage system, end cover subassembly include mass flow piece and end cover, the mass flow piece is used for being connected with the electrode assembly electricity, the central axis of end cover with the central axis coincidence of mass flow piece, the end cover includes end cover body and first boss, the central axis of end cover body with the central axis coincidence of first boss, the end cover body is including the orientation the first surface that the mass flow piece set up and the second surface that sets up in opposite directions, first boss for the second surface is sunken, and for the first surface protrusion sets up, the mass flow piece is in orthographic projection on the end cover covers completely first boss. According to the technical scheme, the electrolyte between the current collector and the end cover can be reduced, and the utilization rate of the electrolyte is improved.

Description

End cover assembly, energy storage device and household energy storage system

Technical Field

The application relates to the field of energy storage devices, in particular to an end cover assembly, an energy storage device and a household energy storage system.

Background

Currently, batteries generally include a cell, an end cap assembly, and a housing. The housing accommodates the battery cell, and the end cap assembly can seal the battery cell with the housing. The end cover assembly generally comprises a current collector and an end cover, excessive electrolyte is easy to stay in a gap between the current collector and the end cover, and the electrolyte cannot participate in charge-discharge reaction of the battery, so that the utilization rate of the electrolyte is low.

Disclosure of Invention

The embodiment of the application provides an end cover assembly, an energy storage device and a household energy storage system, which can reduce electrolyte between a current collector and an end cover and improve the utilization rate of the electrolyte.

In a first aspect, the present application provides an end cap assembly comprising:

a current collector for electrically connecting with the electrode assembly; a kind of electronic device with high-pressure air-conditioning system

The central axis of end cover with the central axis coincidence of mass flow spare, the end cover includes end cover body and first boss, the central axis of end cover body with the central axis coincidence of first boss, the end cover body includes towards the first surface that the mass flow spare set up and the second surface that sets up in opposite directions, first boss for the second surface is sunken, and for first surface protrusion setting, the mass flow spare is in orthographic projection on the end cover covers completely first boss.

It is understood that a receiving space for receiving electrolyte is formed between the current collector and the end cap. At present, electrolyte between the current collector and the end cover cannot be in contact with the electrode assembly, so that waste of the electrolyte in the part is caused, and the utilization rate of the electrolyte is reduced. The first boss arranged on the first surface can enable the space between the end cover and the current collector to be smaller, so that electrolyte which can be reserved in the space is less, the volume of the electrolyte which cannot be contacted with the motor assembly is reduced, and the utilization rate of the electrolyte is improved.

In one possible implementation manner, the first boss includes a first boss surface, the first boss surface is disposed opposite to the second surface recess, and a depth H of the first boss surface opposite to the second surface recess and a thickness H of the end cover satisfy a relation: H1/H is more than or equal to 1/2 and less than or equal to 4/5.

It will be appreciated that when the degree of recess of the first boss surface is greater (4/5. Ltoreq.h1/H), the degree of protrusion of the other surface of the first boss relative to the end cap body is greater, so that the shape of the end cap is irregular at this time, resulting in the structural strength of the end cap being affected, and thus the structural stability of the energy storage device for which the end cap set is used is affected.

When the concave degree of the first boss is smaller (1/2 is less than or equal to H1/H), the convex degree of the other surface of the first boss relative to the end cover body is smaller. At this time, the degree of change of the space between the end cover and the current collecting piece is small, or more electrolyte remains between the end cover and the current collecting piece, so that the utilization rate of the electrolyte cannot be effectively improved.

In a possible embodiment, the end cap further comprises a second boss, the second boss is arranged protruding relative to the first boss surface of the first boss, a central axis of the second boss coincides with a central axis of the first boss, the second boss comprises a first connecting surface facing away from the first boss surface, and the first connecting surface is recessed relative to the second surface.

It will be appreciated that the first connection surface being flush with the second surface may provide a higher degree of flatness in the appearance of the end cap assembly. When the first connecting surface is welded with the module aluminum bar, the module aluminum bar can be abutted with the first connecting surface and the second surface.

In a possible implementation manner, the end cover further comprises a connecting hole, the connecting hole penetrates through the first boss and the second boss along the thickness direction of the end cover, and the central axis of the connecting hole coincides with the central axis of the first boss and the central axis of the second boss;

the current collecting piece comprises a current collecting body and a convex column, the convex column is located on the surface of the current collecting body, which faces the end cover, one end of the convex column, which is far away from the current collecting body, penetrates through the connecting hole, and the surface of the convex column, which is far away from the current collecting body, is flush with the first connecting surface.

It will be appreciated that the protrusion of the header is flush with the first connection surface to provide a smoother appearance of the end cap assembly, thereby increasing the flatness of the joint between the first connection surface and the protrusion and the aluminum bar of the module.

In a possible implementation manner, the first boss comprises a second boss surface opposite to the first boss surface, the connecting hole penetrates through the first boss surface and the second boss surface, the connecting hole comprises a first hole and a second hole which are communicated, the first hole and the second hole are sequentially arranged in the direction of the end cover towards the current collector, and the maximum radial dimension of the first hole is smaller than or equal to the minimum radial dimension of the second hole;

the convex column comprises a first column body, a second column body and a third column body, the current collecting body faces the end cover, the first column body, the second column body and the third column body are sequentially connected, the radial size of the first column body is larger than that of the second hole, one end, away from the current collecting body, of the first column body is abutted to the second convex table surface, the second column body is located in the second hole, the second column body is abutted to the hole wall of the second hole, the third column body is located in the first hole, and the third column body is abutted to the hole wall of the first hole.

It can be understood that the first column body can be propped against the second raised table surface, so that the end cover is limited in the thickness direction, and the structure of the current collecting body is prevented from being damaged due to the fact that the end cover extrudes the current collecting body.

The second post can be held against the wall of the second hole so that the current collector can be electrically connected with the end cap. Because the pore wall of the second hole is obliquely arranged, the area of the abutting surface of the second hole and the second column is larger, and the stability of the electric connection between the current collector and the end cover can be further improved.

The third cylinder can support with the pore wall of first hole, and the pore wall of first hole can carry out spacingly to the third cylinder in its circumference to increase the connection stability of collector and end cover.

In a possible embodiment, the end cover body includes a second connection surface, the second connection surface being disposed around the periphery of the first boss surface, the second connection surface being connected between the second surface and the first boss surface;

the end cover is provided with a first thinning groove and a second thinning groove, the first thinning groove and the second thinning groove are arranged in a sunken mode through the first boss surface, the first thinning groove is arranged around the periphery of the second boss, and the second thinning groove is arranged around the periphery of the first thinning groove and is arranged at intervals with the first thinning groove.

It can be appreciated that the first thinning groove and the second thinning groove can enclose an annular explosion-proof valve, when the internal pressure of the energy storage device using the end cover assembly is too high, the pressure can break the first thinning groove and the second thinning groove, and part of the boss in front of the first thinning groove and the second thinning groove can be lifted, so that a pressure relief opening is provided for gas or liquid in the energy storage device, and explosion caused by the too high internal pressure of the energy storage device is avoided.

In a possible embodiment, the depth H1 of the first boss face recess relative to the second surface is between 0.5mm and 1.5 mm.

It will be appreciated that when the depth of the first boss face depression relative to the second surface is small (less than 0.5 mm), the distance the first boss projects relative to the first surface is small. Therefore, the space between the end cover and the current collecting plate cannot be effectively reduced due to the arrangement of the first boss, so that more electrolyte is retained in the space between the end cover and the current collecting plate.

When the first boss face is relative to the sunken degree of depth of second surface great (be greater than 1.5 mm), the protrusion distance of first boss relative to the first surface is great, and the stress concentration takes place more easily to receive the impact force in first boss department, and then leads to the structural strength of end cover weaker and can't guarantee the structural stability of end cover subassembly.

In a possible embodiment, the end cover further includes a connection portion connected to the first surface, the connection portion being disposed around the first boss with a gap therebetween.

It will be appreciated that the end cap assembly may be required to cooperate with the housing of the energy storage device to form a receiving space, and the connection portion may provide a connection location for the end cap assembly and the housing.

In a second aspect, the present application further provides an energy storage device, including an electrode assembly and an end cap assembly as described above, the end cap assembly being located at a bottom end of the energy storage device, the current collector including a protrusion and a current collecting body, the protrusion being connected to a side of the current collecting body facing away from the end cap, the protrusion being connected with the electrode assembly.

In a third aspect, the present application provides a household energy storage system comprising an energy storage device as described above loaded, said energy storage device being adapted to power said load.

Drawings

In order to more clearly illustrate the technical solutions of the present application, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained by those skilled in the art without the inventive effort.

FIG. 1 is a schematic illustration of a household energy storage system provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of the energy storage device provided in FIG. 1;

fig. 3 is a schematic structural view of the unit cell shown in fig. 2;

fig. 4 is a schematic view of the current collector of fig. 3 at an angle;

fig. 5 is a schematic view of another angle configuration of the current collector shown in fig. 4;

FIG. 6 is a schematic view of the end cap shown in FIG. 3;

FIG. 7 is a schematic cross-sectional view of the end cap shown in FIG. 6;

fig. 8 is a schematic view of the assembly of the current collector and end cap of fig. 2.

Reference numerals: the energy storage system 1000, the conversion device 100, one user load 200, another user load 300, the energy storage device 400, the module aluminum bar 410, the plurality of battery cells 420, the case 421, the end cap assembly 422, the current collector 423, the end cap 424, the current collector body 4231, the boss 4232, the boss 4236, the through hole 4237, the abutment plate 4238, the first post 4233, the second post 4234, the third post 4235, the end cap body 4241, the first boss 4242, the second boss 4243, the connection portion 4244, the first surface 4245, the second surface 4246, the middle region 4247, the edge region 4248, the first boss surface 4251, the second boss surface 4252, the second connection surface 4249, the depth H1 of the first boss surface 4251 recessed relative to the second surface 4246, the thickness H of the end cap 424, the first thinning groove 4253, the second thinning groove 4254, the first connection surface 4255, the peripheral side 4256, the connection hole 4257, the first hole 4258, and the second hole 4259.

Detailed Description

For ease of understanding, the terms involved in the embodiments of the present application are explained first.

And/or: merely one association relationship describing the associated object, the representation may have three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone.

A plurality of: refers to two or more.

And (3) connection: it is to be understood in a broad sense that, for example, a is linked to B either directly or indirectly via an intermediary.

The following description of the embodiments of the present application will be made with reference to the accompanying drawings.

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 photovoltaics, wind power, water potential and the like, and the problems of strong intermittence, large fluctuation of wind energy, solar energy and the like generally exist, so that an electric network is unstable, electricity consumption is insufficient in peak electricity, and electricity consumption is too low. Unstable voltages also cause damage to the power, and therefore may cause "wind and light rejection" problems due to insufficient power requirements or insufficient power grid acceptance, which require energy storage to be overcome. 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 chemical battery is arranged in the energy storage device, chemical elements in the chemical battery 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 power generation side energy storage, electric network side energy storage, renewable energy grid-connected energy storage, user side energy storage and the like, 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 main operation modes of the small and medium-sized energy storage electric cabinet applied to the industrial and commercial energy storage scenes (banks, shops and the like) at the user side and the household small-sized energy storage box applied to the household energy storage scene at the user side are peak clipping and valley filling. Because there is great price difference in the electric charge of peak valley position according to the power consumption demand, in order to reduce the cost after the user has energy storage equipment, generally charge processing to energy storage cabinet/case in the low valley period of electric charge, the peak period of electric charge releases the electricity in the energy storage equipment again and uses to reach the purpose of saving the electric charge. In addition, in remote areas and areas with high occurrence of natural disasters such as earthquake, hurricane and the like, the household energy storage device is equivalent to the fact that a user provides a standby power supply for the user and the power grid, and inconvenience caused by frequent power failure due to disasters or other reasons is avoided.

In the embodiment of the present application, a household energy storage scenario in user side energy storage is taken as an example for explanation, please refer to fig. 1, fig. 1 is a household energy storage system 1000 provided in the embodiment of the present application.

The household energy storage system 1000 includes an electric energy conversion device 100 (photovoltaic panel), one user load 200 (street lamp), another user load 300 (household appliance), etc., and an energy storage device 400. The energy storage device 400 is a small energy storage box, and can be installed on an outdoor wall in a wall hanging manner. In particular, the photovoltaic panel may convert solar energy into electric energy during low electricity price periods, and the energy storage device 400 is used to store the electric energy and supply the electric energy to street lamps and household appliances for use during electricity price peaks or to supply power during power outage/power outage of the power grid. It should be noted that the energy storage device 400 is not limited to the home energy storage scenario.

Referring to fig. 2, fig. 2 is a schematic structural diagram of the energy storage device 400 provided in fig. 1. The energy storage device 400 may include a modular aluminum bar 410 and a plurality of battery cells 420. The plurality of unit cells 420 are arranged in an array, and the module aluminum bar 410 may be welded with electrodes of the unit cells 420, thereby connecting the plurality of unit cells 420 in series or in parallel.

Currently, a unit cell generally includes an end cap assembly, a case, an electrode assembly, and an electrolyte. The end cover assembly can be in sealing connection with the shell to form an accommodating space. The electrode assembly and the electrolyte may be located in the receiving space, and the electrode assembly may be immersed in the electrolyte. The end cover assembly generally comprises a current collector and an end cover, excessive electrolyte is easy to stay in a gap between the current collector and the end cover, and the electrolyte cannot participate in charge-discharge reaction of the battery, so that the utilization rate of the electrolyte is low.

Based on the above, the embodiment of the application provides a single battery, which can reduce part of electrolyte between a current collector and an end cover and improve the utilization rate of the electrolyte.

Referring to fig. 3, fig. 3 is a schematic structural diagram of the unit cell 420 shown in fig. 2. The unit cell 420 includes a case 421, an electrode assembly (not shown), an electrolyte (not shown), and an end cap assembly 422. The housing 421 may be a cylindrical housing, and one end of the housing 421 is provided with an opening. The electrode assembly is mounted inside the case 421. The electrolyte is disposed in the sealed space formed by the case 421 and the cap assembly 422, and the electrode assembly is immersed in the electrolyte. The cap assembly 422 is connected to the opening of the case 421 in the height direction of the unit cells 420, and is electrically connected to the electrode assembly. Illustratively, the end cap assembly 422 may be positioned at the bottom end of the cell 420 when the cell 420 is placed in a use environment.

It can be appreciated that when the end cap assembly 422 is positioned at the bottom end of the unit cell 420, by configuring the internal space in the end cap assembly 422, the volume of electrolyte that is not in the end cap assembly 422 can be reduced, so that more electrolyte can react with the electrode assembly positioned above the end cap assembly 422, and the utilization of electrolyte can be improved.

Referring again to fig. 3, end cap assembly 422 includes a current collector 423 and an end cap 424. The current collector 423 and the end cap 424 are stacked. And the central axis of the current collector 423 coincides with the central axis of the end cap 424. One side of the current collector 423 is electrically connected to the electrode assembly. The opposite side of the current collector 423 is electrically connected to the end cap 424. The current collector 423 is provided at a side of the end cap 424 facing the case 421.

It should be noted that fig. 3 is only for schematically describing the connection relationship between the current collector 423 and the end cap 424, and is not limited to the connection location, specific configuration and number of the respective devices. While the illustrated construction of the embodiments of the present application does not constitute a particular limitation of the end cap assembly 422. In other embodiments of the present application, the end cap assembly 422 may include more or fewer components than shown in FIG. 3, or certain components may be combined, certain components may be split, or a different arrangement of components may be provided. The components shown in fig. 3 may be implemented in hardware, software, or a combination of software and hardware.

Referring to fig. 4 and 5 in combination, fig. 4 is a schematic view illustrating an angle of the current collector 423 shown in fig. 3, and fig. 5 is a schematic view illustrating another angle of the current collector 423 shown in fig. 4. The current collector 423 includes a current collecting body 4231 and a boss 4232. The boss 4232 is connected to one side surface of the current collecting body 4231.

The header also includes a plurality of tabs 4236, a plurality of through holes 4237, and a plurality of abutment plates 4238. The protrusion 4236 is concavely provided from a side surface of the collecting body 4231 where the boss 4232 is provided. On the side of the collecting body 4231 where the boss 4232 is not provided, the corresponding position of the boss 4236 is provided to be protruded with respect to the surface of the collecting body 4231. Three of the projections 4236 are provided, and the three projections 4236 are provided along the circumferential direction of the boss 4232. The angle between two adjacent lugs 4236 may be 60 °. Each of the projections 4236 extends from the edge of the current collecting body 4231 toward the center.

It is understood that the protrusions 4236 are convexly disposed at the surface of the current collecting body 4231 toward the electrode assembly of the unit cell 420, and therefore, the protrusions 4236 may be welded with the electrode assembly, thereby achieving the electrical connection of the current collecting member 423 with the electrode assembly.

The through holes 4237 penetrate the current collecting body 4231 in the thickness direction of the current collecting body 4231. The through hole 4237 is spaced apart from the protrusion 4236. The plurality of through holes 4237 are arranged in an array. As shown in fig. 4, a region is formed between each two of the projections 4236. The three tabs 4236 divide the current collecting body 4231 into three regions. The plurality of through holes 4237 may be uniformly distributed in the three regions.

It is understood that the through holes 4237 may allow the gas or liquid of the unit cells 420 to pass through. When the internal pressure of the unit cell 420 is excessively large. The gas and/or liquid in the single battery 420 passes through the through hole 4237 first, and then the explosion-proof valve on the end cover 424 is opened to complete pressure relief, so that the explosion of the single battery 420 is avoided.

In addition, the fluid passes through the through holes 4237 of the current collector 423, and the current collector body 4231 can block the fragments of the internal components of the unit cells 420 flowing with the fluid, so that the fragments are prevented from passing through the current collector body 4231 and collecting to the explosion-proof valve of the end cover 424, and the explosion-proof valve is blocked to fail.

A plurality of abutment plates 4238 may be connected to the periphery of the current collecting body 4231. The plurality of abutment plates 4238 are disposed at intervals. The abutment plate 4238 is disposed at a distance from the boss 4236. The abutting plate 4238 extends from the periphery of the current collecting body 4231 to the side of the current collecting body 4231 where the boss 4232 is provided. Illustratively, there may be nine abutment plates 4238. Each three abutment plates 4238 may be located at the edge of one region formed by two adjacent protrusions 4236.

It will be appreciated that the tabs 4232 may abut the surface of the end cap 424 facing the current collector 423 when the current collector 423 is pressed by the electrode assembly toward the end cap 424 (e.g., a battery drop). Thereby buffering the external force, preventing the current collector 423 from being deformed after being impacted, and finally causing the single battery 420 to fail.

The boss 4232 includes a first cylinder 4233, a second cylinder 4234, and a third cylinder 4235, and the first cylinder 4233, the second cylinder 4234, and the third cylinder 4235 are sequentially connected. One side of the first cylinder 4233 is connected to the current collecting body 4231, and the first cylinder 4233 may be connected to a central position of the current collecting body 4231. The other side of the first cylinder 4233, which is remote from the current collecting body 4231, is connected to the second cylinder 4234. The radial dimension of the first cylinder 4233 may be constant in the thickness direction of the current collector 423. That is, the first cylinder 4233 may be cylindrical in shape.

The second cylinder 4234 is connected to the end surface of the first cylinder 4233 remote from the current collecting body 4231. The radial dimension of the side of the second cylinder 4234 connected to the first cylinder 4233 may be smaller than the radial dimension of the first cylinder 4233. The second post 4234 has a maximum radial dimension that is less than the minimum radial dimension of the first post 4233. The second cylinder 4234 gradually becomes smaller in radial dimension in a direction away from the first cylinder 4233. The rate of change of the radial dimension of the second cylinder 4234 may be a first rate. Illustratively, the second cylinder 4234 may be in the shape of a circular table. The peripheral side surface of the second cylinder 4234 may be the peripheral side surface of a truncated cone.

The third cylinder 4235 is connected to an end face of the second cylinder 4234 remote from the first cylinder 4233. The radial dimension of the side of the third cylinder 4235 where it is connected to the second cylinder 4234 may be the same as the radial dimension of the second cylinder 4234. The third cylinder 4235 may be tapered in radial dimension in a direction away from the second cylinder 4234. The rate of change of the radial dimension of the third cylinder 4235 may be a second rate. The second rate may be less than the first rate. The third cylinder 4235 may be, for example, a circular truncated cone in shape. The peripheral side surface of the third cylinder 4235 may be the peripheral side surface of a circular truncated cone. Alternatively, the third cylinder 4235 may be a cylinder, and the circumferential side surface of the third cylinder 4235 may be a circumferential side surface of the cylinder. That is, the radial dimension of the third cylinder 4235 may be constant at all times.

Referring to fig. 6 and 7 in combination, fig. 6 is a schematic structural view of the end cap 424 shown in fig. 3, and fig. 7 is a schematic sectional view of the end cap 424 shown in fig. 6. The end cap 424 includes an end cap body 4241, a first boss 4242, a second boss 4243, and a connection portion 4244. The central axis of the end cap body 4241, the central axis of the first boss 4242, the central axis of the second boss 4243, and the central axis of the connection portion 4244 all coincide.

The end cap body 4241 includes a first surface 4245 and a second surface 4246 disposed opposite each other along a thickness direction thereof, the first surface 4245 being a surface of the end cap body 4241 facing the current collector 423, and the second surface 4246 being a surface of the end cap body 4241 facing away from the current collector 423. The end cap body 4241 further comprises a middle region 4247 and an edge region 4248. The edge region 4248 is disposed about the intermediate region 4247 and is connected to the intermediate region 4247.

The first boss 4242 is connected to the first surface 4245 of the end cap body 4241 and is located in the intermediate region 4247 of the end cap body 4241. The first boss 4242 is convexly disposed with respect to the first surface 4245. And the first boss 4242 is concavely disposed relative to the second surface 4246.

It will be appreciated that a receiving space is formed between the current collector 423 and the end cap 424, which can receive an electrolyte. The electrolyte between the current collector 423 and the end cap 424 cannot contact the electrode assembly at present, so that the electrolyte is wasted in this portion, and the use ratio of the electrolyte is reduced. The first boss 4242 disposed on the first surface 4245 may reduce the space between the end cap 424 and the current collector 423, thereby reducing the volume of electrolyte that cannot contact the motor assembly and improving the utilization rate of electrolyte.

The first boss 4242 includes a first boss face 4251 and a second boss face 4252 disposed opposite to each other in the thickness direction. The first boss surface 4251 is a surface of the first boss 4242 facing the end cap body 4241, and the first boss surface 4251 is concavely disposed relative to the second surface 4246. The first land 4251 may be disposed parallel to the second surface 4246. The second boss surface 4252 is a surface of the first boss 4242 facing away from the end cap body 4241, and the second boss surface 4252 is disposed in a protruding manner with respect to the first surface 4245.

The end cap body 4241 further comprises a second connection face 4249, the second connection face 4249 is disposed around the periphery of the first boss face 4251, and the second connection face 4249 is connected between the second surface 4246 and the first boss face 4251. The second connecting surface 4249 is disposed at an angle to the second surface 4246. For example, the second connection surface 4249 may form an obtuse angle with the second surface 4246. In other words, the first land 4251 and the second surface 4246 are connected by the second connection surface 4249. The first boss surface 4251 is disposed at an angle to the second connection surface 4249. Illustratively, the depth H1 of the depression of the first land 4251 relative to the second surface 4246 and the thickness H of the end cap 424 satisfy the relationship: H1/H is more than or equal to 1/2 and less than or equal to 4/5. The depth H1 of the depression of the first land 4251 relative to the second surface 4246 is between 0.5mm and 1.5mm (inclusive of the end points 0.5mm and 1.5 mm).

It will be appreciated that when the degree of dishing of the first land 4251 is greater (4/5.ltoreq.h1/H), and/or when the depth of dishing of the first land 4251 relative to the second surface 4246 is greater (greater than 1.5 mm). The second boss face 4252 of the first boss 4242 is raised relative to the end cap body 4241 to a greater extent, and the shape of the end cap 424 is less regular, resulting in an impact on the structural strength of the end cap 424 and thus the structural stability of the energy storage device 400 in which the end cap assembly 422 is used.

The second boss face 4252 of the first boss 4242 is less raised relative to the end cap body 4241 when the degree of depression of the first boss 4242 is less (1/2+.h1/H) and/or when the depth of depression of the first boss face 4251 relative to the second face 4246 is less (less than 0.5 mm). At this time, the space between the end cap 424 and the current collector 423 is less varied, or more electrolyte remains between the end cap 424 and the current collector 423, which cannot effectively improve the utilization rate of the electrolyte.

The ratio of the depth H1 of the first boss surface 4251 relative to the second surface 4246 to the thickness H of the end cap 424 is between 1/2 and 4/5 (including the end point values of 1/2 and 4/5), and/or the depth H1 of the first boss surface 4251 relative to the second surface 4246 is between 0.5mm and 1.5mm (including the end point values of 0.5mm and 1.5 mm), which not only can reduce the electrolyte retained between the end cap 424 and the current collector 423, but also can ensure the structural strength of the end cap assembly 422, so that the structural strength of the end cap assembly 422 meets the use requirements of the single battery 420.

Referring to fig. 7 again, the end cap 424 is further provided with a first thinning groove 4253 and a second thinning groove 4254, and the first thinning groove 4253 and the second thinning groove 4254 are concavely disposed on the first boss surface 4251. The first and

second thinning grooves

4253, 4254 are each circumferentially disposed about the center of the first boss 4242. The first thinning groove 4253 is provided around the periphery of a second boss 4243 described below. The second thinning groove 4254 is circumferentially disposed about the first thinning groove 4253. The second thinning groove 4254 is disposed proximate the second connection face 4249 of the end cap body 4241. The first thinning groove 4253 and the second thinning groove 4254 are provided at a spacing.

It is understood that the first and

second thinning grooves

4253, 4254 may thin the material of the first boss 4242 at the location thereof, thereby weakening the structural strength of the first boss 4242 at the location thereof. The first and

second slots

4253, 4254 may be formed when the end cap 424 is stamped. The first and second thinned

grooves

4253, 4254 may enclose an annular explosion-proof valve structure. The explosion proof valve structure is offset from the second surface 4246 of the end cap 424 to avoid accidental scoring of the explosion proof valve structure by external objects. In the event that the internal pressure of the energy storage device 400 in which the end cap assembly 422 is used is excessive, the pressure may rupture the first and/or

second thinning grooves

4253, 4254. A portion of the first boss 4242 between the first thinning groove 4253 and the second thinning groove 4254 may be lifted, so as to provide a pressure relief port for gas or liquid in the unit cell 420, and prevent explosion caused by over-high pressure in the unit cell 420.

With continued reference to fig. 7, the second boss 4243 is connected to the first boss face 4251. The second boss 4243 is provided to be protruded with respect to the first boss face 4251, and a protruding direction of the second boss 4243 is opposite to a protruding direction of the first boss 4242. The second boss 4243 includes a first connection face 4255 and a peripheral side face 4256. The first connection face 4255 is a surface of the second boss 4243 facing away from the first boss face 4251. The first attachment surface 4255 may be flush with the second surface 4246. The peripheral side surface 4256 of the second boss 4243 may be a peripheral side surface 4256 of a truncated cone, and the cross-sectional diameter of the peripheral side surface 4256 of the second boss 4243 may be sequentially smaller from the first boss surface 4251 in a direction away from the first boss surface 4251. The second boss 4243 may also be illustratively recessed from the second boss face 4252 of the first boss 4242 and protruding relative to the first boss face 4251 of the first boss 4242. The thickness of the second boss 4243 may be the same as the thickness of the first boss 4242.

It will be appreciated that the first connection surface 4255 being flush with the second surface 4246 may provide a higher flatness of the outer appearance of the end cap assembly 422. When the first connection surface 4255 is welded to the die set aluminum bar 410, the die set aluminum bar 410 may abut the first connection surface 4255 and the second surface 4246.

In other possible embodiments, the first attachment surface 4255 may also be recessed relative to the second surface 4246. It will be appreciated that after the first connection face 4255 is welded to the electrode assembly, the first connection face 4255 may be covered with a portion of the solder. The solder-covered first attachment surface 4255 may be flush with the second surface 4246 to provide a more planar appearance to the end cap assembly 422. The end cap 424 is further provided with a connection hole 4257, and the connection hole 4257 penetrates the first boss 4242 and the second boss 4243 in the thickness direction of the end cap 424. The central axis of the connection hole 4257 may coincide with the central axes of the first boss 4242 and the second boss 4243. Specifically, the connection hole 4257 penetrates the first boss surface 4251 and the second boss surface 4252 of the first boss 4242, and the first connection surface 4255 of the second boss 4243.

The connection hole 4257 includes a first hole 4258 and a second hole 4259 in communication. The first holes 4258 and the second holes 4259 are sequentially disposed in a direction of the end cap 424 toward the current collector 423. The first hole 4258 extends through the first connection face 4255. The radial dimension of the first holes 4258 may gradually decrease in a direction away from the collecting body 4231, and the radial dimension of the first holes 4258 may decrease at a first rate. Alternatively, the radial dimension of the first holes 4258 may be constant in a direction away from the collector body 4231.

A second hole 4259 penetrates the first boss face 4251 and the second boss face 4252. The minimum radial dimension of the second holes 4259 may be equal to the maximum radial dimension of the first holes 4258. The radial dimension where the bore wall of the second bore 4259 intersects the bore wall of the first bore 4258 is the minimum radial dimension of the second bore 4259 and the maximum radial dimension of the first bore 4258. The radial dimension of the second holes 4259 gradually decreases in a direction away from the collecting body 4231. The radial dimension of the second holes 4259 may be tapered at a second rate, the first rate being less than the second rate.

The connecting portion 4244 is connected to the first surface 4245 and is disposed in a protruding manner with respect to the first surface 4245. The connection portion 4244 is located in the edge region 4248 and disposed around the first boss 4242, with a gap between the connection portion 4244 and the first boss 4242. And a side of the connection portion 4244 remote from the first boss 4242 may be concavely disposed with respect to the outer circumference of the end cap body 4241.

It will be appreciated that the end cap assembly 422 needs to cooperate with the housing 421 of the energy storage device 400 to form a receiving space. The connection 4244 may provide a connection location for the end cap assembly 422 and the housing 421. The side of the connection portion 4244 remote from the first boss 4242 may abut against the inner wall of the case 421.

Referring to fig. 8, fig. 8 is a schematic view illustrating the assembly of the current collector 423 and the end cap 424 shown in fig. 2. The first surface 4245 of the end cap 424 is disposed toward the collector 423. I.e. the second boss face 4252 of the first boss 4242 is disposed towards the current collector 423. The front projection of the current collector 423 onto the end cap 424 completely covers the first boss 4242.

The side of the current collector 423 provided with the boss 4232 is disposed toward the first surface 4245 of the end cap body 4241. The end of the boss 4232 of the current collector 423, which is far away from the current collector body 4231, is penetrated through the connection hole 4257. The surface of the boss 4232 remote from the collector body 4231 is flush with the first connection face 4255. One end of the first pillar 4233 of the pillar 4232, which is far away from the current collecting body 4231, abuts against the second boss surface 4252. The second post 4234 of the post 4232 is located in the second hole 4259, and the peripheral side surface of the second post 4234 abuts against the hole wall of the second hole 4259. The third post 4235 of the post 4232 is located within the first aperture 4258. The peripheral side surface of the third cylinder 4235 abuts against the wall of the first hole 4258.

It can be appreciated that the end surface of the first pillar 4233 of the boss 4232 may abut against the second boss 4252, so that the end cap 424 is limited in the thickness direction thereof, and the end cap 424 is prevented from pressing the current collecting body 4231 to damage the structure of the current collecting body 4231.

The second post 4234 of the post 4232 may abut the wall of the second hole 4259 such that the current collector 423 may be electrically connected with the end cap 424. Since the hole wall of the second hole 4259 is inclined, the area of the contact surface between the second hole 4259 and the second post 4234 is large, so that the stability of the electrical connection between the current collector 423 and the end cap 424 can be increased.

The third column 4235 of the boss 4232 may abut against the hole wall of the first hole 4258, and the hole wall of the first hole 4258 may limit the third column 4235 in the circumferential direction, so as to increase the connection stability between the current collecting member 423 and the end cover 424, and achieve the uniformity of current collecting of the current collecting member 423.

The connection portion 4244 is fixedly connected with the opening of the case 421. Illustratively, the side of the connection 4244 remote from the first boss 4242 may be welded to the opening of the housing 421 to sealingly connect the end cap assembly 422 to the housing 421.

In the energy storage device 400, the plurality of unit cells 420 may be arranged in an array, and the second surface 4246 of the end cap 424, the second connection surface 4249 of the second boss 4243, and the surface of the boss 4232 of the current collector 423 may be electrically connected to the module aluminum bar 410 of the energy storage device 400, so that the plurality of unit cells 420 are connected in series or parallel.

It will be appreciated that the flush alignment of the posts 4232 of the header 423 with the first connection surface 4255 may provide a smoother appearance of the end cap assembly 422, thereby increasing the flatness of the weld between the surface formed by the first connection surface 4255 and the posts 4232 and the modular aluminum bar 410.

The foregoing has outlined rather broadly the more detailed description of embodiments of the present application, wherein specific examples are provided herein to illustrate the principles and embodiments of the present application, the above examples being provided solely to assist in the understanding of the methods of the present application and the core ideas thereof; meanwhile, as those skilled in the art will have modifications in the specific embodiments and application scope in accordance with the ideas of the present application, the present description should not be construed as limiting the present application in view of the above.

Claims

1. An end cap assembly (422) comprising:

a current collector (423) for electrically connecting with the electrode assembly; a kind of electronic device with high-pressure air-conditioning system

End cover (424), end cover (424) include end cover body (4241) and first boss (4242), end cover body (4241) collector (423) with the central axis coincidence of first boss (4242) three, end cover body (4241) include towards first surface (4245) and the second surface (4246) that set up in opposite directions that collector (423) set up, first boss (4242) for second surface (4246) is sunken, and for first surface (4245) protrusion setting, the orthographic projection of collector (423) on end cover (424) covers entirely first boss (4242).

2. The end cap assembly (422) of claim 1 wherein the first boss (4242) comprises a first boss face (4251), the first boss face (4251) being recessed relative to the second surface (4246), a depth H1 of the first boss face (4251) recess relative to the second surface (4246) satisfying a relationship with a thickness H of the end cap (424): H1/H is more than or equal to 1/2 and less than or equal to 4/5.

3. The end cap assembly (422) of claim 2 wherein the end cap (424) further comprises a second boss (4243), the second boss (4243) being disposed in convex relation to a first boss face (4251) of the first boss (4242), a central axis of the second boss (4243) coinciding with a central axis of the first boss (4242), the second boss (4243) comprising a first connection face (4255) facing away from the first boss face (4251), the first connection face (4255) being recessed relative to the second face (4246).

4. The end cap assembly (422) of claim 3 wherein said end cap (424) further comprises a connecting hole (4257), said connecting hole (4257) extending through said first boss (4242) and said second boss (4243) in a thickness direction of said end cap (424), a central axis of said connecting hole (4257) coinciding with a central axis of said first boss (4242) and a central axis of said second boss (4243);

the current collecting piece (423) comprises a current collecting body (4231) and a convex column (4232), the convex column (4232) is located on the surface of the current collecting body (4231) facing the end cover (424), one end of the convex column (4232) away from the current collecting body (4231) penetrates through the connecting hole (4257), and the surface of the convex column (4232) away from the current collecting body (4231) is flush with the first connecting surface (4255).

5. The end cap assembly (422) of claim 4 wherein said first boss (4242) includes a second boss face (4252) disposed opposite said first boss face (4251), said connection aperture (4257) extending through said first boss face (4251) and said second boss face (4252), said connection aperture (4257) including first and second apertures (4258, 4259) in communication, said first aperture (4258) and said second aperture (4259) being disposed in sequence in a direction of said end cap (424) toward said collector (423), a maximum radial dimension of said first aperture (4258) being less than or equal to a minimum radial dimension of said second aperture (4259);

the convex column (4232) comprises a first column (4233), a second column (4234) and a third column (4235), the current collecting body (4231) faces the end cover (424), the first column (4233), the second column (4234) and the third column (4235) are sequentially connected, the radial size of the first column (4233) is larger than that of the second hole (4259), one end of the first column (4233) away from the current collecting body (4231) is propped against the second convex table (4252), the second column (4234) is located in the second hole (4259), the second column (4234) is propped against the hole wall of the second hole (4259), the third column (4235) is located in the first hole (4258), and the third column (4235) is propped against the hole wall of the first hole (4258).

6. The end cap assembly (422) of any of claims 2-5 wherein the end cap body (4241) comprises a second connection face (4249), the second connection face (4249) being disposed around the periphery of the first land (4251), the second connection face (4249) being connected between the second face (4246) and the first land (4251);

the end cover (424) is provided with a first thinning groove (4253) and a second thinning groove (4254), the first thinning groove (4253) and the second thinning groove (4254) are arranged in a concave mode through the first boss surface (4251), the first thinning groove (4253) is arranged around the periphery of the second boss (4243), and the second thinning groove (4254) is arranged around the periphery of the first thinning groove (4253) and is arranged with the first thinning groove (4253) at intervals.

7. The end cap assembly (422) of claim 4 wherein the depth H1 of the first land (4251) recess relative to the second surface (4246) is between 0.5mm and 1.5 mm.

8. The end cap assembly (422) of claim 7 wherein said end cap (424) further comprises a connecting portion (4244), said connecting portion (4244) being connected to said first surface (4245), said connecting portion (4244) being disposed about said first boss (4242), a gap being provided between said connecting portion (4244) and said first boss (4242).

9. An energy storage device (400) comprising an electrode assembly and an end cap assembly (422) according to any of claims 1-8, said end cap assembly (422) being located at one end of said energy storage device (400), said current collector (423) comprising a protrusion (4236) and a current collector body (4231), said protrusion (4236) being connected to a side of said current collector body (4231) facing away from said end cap (424), said protrusion (4236) being connected to said electrode assembly.

10. A household energy storage system (1000), comprising a load (300) as claimed in claim 9, the energy storage device (400) being adapted to power the load (300).