CN116487828A

CN116487828A - Energy storage device and electric equipment

Info

Publication number: CN116487828A
Application number: CN202310684242.6A
Authority: CN
Inventors: 钟德良
Original assignee: Xiamen Hithium Energy Storage Technology Co Ltd
Current assignee: Xiamen Hithium Energy Storage Technology Co Ltd
Priority date: 2023-06-09
Filing date: 2023-06-09
Publication date: 2023-07-25

Abstract

The application discloses energy storage device and consumer, energy storage device includes casing, electrode assembly, end cover subassembly and collector. The housing includes a receiving cavity having an opening; the electrode assembly is accommodated in the accommodating cavity; the end cover assembly comprises an end cover plate and an explosion-proof valve, and the end cover plate is connected to the shell and seals the opening; the end cover plate is provided with a first surface facing the electrode assembly and a second surface arranged opposite to the first surface, and is also provided with a vent hole penetrating through the first surface and the second surface, and the explosion-proof valve seals the vent hole; the current collector is arranged in the accommodating cavity and comprises an end cover connecting part and a tab connecting part connected with the end cover connecting part, the end cover connecting part is electrically connected with the end cover plate, and the tab connecting part is electrically connected with the electrode assembly; the explosion-proof valve is provided with a first projection on the first surface, a second projection on the first surface, and the first projection and the second projection are not overlapped.

Description

Energy storage device and electric equipment

Technical Field

The application relates to the technical field of energy storage, in particular to an energy storage device and electric equipment comprising the same.

Background

The battery is used as a new energy battery, has the advantages of high energy density, long cycle life, good safety, green and environment protection and the like, and is widely applied. As the demand for batteries has increased, performance requirements in all aspects have increased, particularly with respect to cycle performance and safety performance.

In the related art, a battery is generally composed of a battery top cover, an electrode assembly, and a case. The actual production process is to manufacture a battery top cover, an electrode assembly and a shell respectively, then use a current collector to weld a pole post of the battery top cover and a pole lug of the electrode assembly respectively, then put the electrode assembly into the shell, and then use the battery top cover to cover an opening of the shell and then weld and seal the shell so as to form a basic structure of the battery. Then, the electrolyte is injected manually through the electrolyte injection Kong Jiazhu arranged on the top cover of the battery, and the electrolyte injection hole is welded and sealed after the completion.

In the recycling process of the battery, gas is generated due to various reasons such as decomposition of electrolyte, exceeding of moisture in the shell, and the like, so that the cycle life and the rate performance are deteriorated. In the related art, an explosion-proof valve is usually arranged on a top cover of a battery, and when the gas in the battery reaches an explosion-proof point critical value, the explosion-proof valve is broken through by the gas, and the gas in a shell is released in time, so that the explosion of the battery is avoided.

However, because the pressure of the gas generated in the battery is high, the gas can impact the current collector, so that the current collector is attached to the top cover of the battery to block the gas leakage channel where the explosion-proof valve is located, and the gas cannot be timely discharged.

Disclosure of Invention

The embodiment of the application provides an energy storage device and electric equipment to solve the current collector that exists among the related art and block off the air leakage passageway easily, cause the unable problem of in time letting out of gas.

The energy storage device comprises a shell, an electrode assembly, an end cover assembly and a current collector. The housing includes a receiving cavity having an opening; the electrode assembly is accommodated in the accommodating cavity; the end cover assembly comprises an end cover plate and an explosion-proof valve, wherein the end cover plate is connected to the shell and seals the opening; the end cover plate is provided with a first surface facing the electrode assembly and a second surface arranged opposite to the first surface, the end cover plate is also provided with a gas leakage hole penetrating through the end cover plate, and the explosion-proof valve seals the gas leakage hole; the current collector is arranged in the accommodating cavity and comprises an end cover connecting part and a tab connecting part connected with the end cover connecting part, the end cover connecting part is electrically connected with the end cover plate, and the tab connecting part is electrically connected with the electrode assembly; the explosion-proof valve is characterized in that the tab connection part is provided with a first projection on the first surface along the height direction of the shell, the explosion-proof valve is provided with a second projection on the first surface, and the first projection and the second projection are not overlapped.

In this application embodiment, along the direction of height of casing, the utmost point ear connecting portion has first projection on the first surface, and explosion-proof valve has the second projection on the first surface, and first projection and second projection do not overlap, so in the direction of height of casing, the utmost point ear connecting portion of collector staggers with explosion-proof valve, and when the inside gas that produces of energy memory impacted the collector, the utmost point ear connecting portion also can not shelter from explosion-proof valve for gas can break explosion-proof valve in time release, avoids energy memory to take place the explosion.

According to some embodiments of the present application, a positioning structure is further provided between the current collector and the end cap plate, the positioning structure comprising:

the positioning bulge is arranged on one of the current collector and the end cover plate;

and the positioning groove is arranged on the other one of the current collector and the end cover plate, and the positioning protrusion is inserted into the positioning groove.

In this application embodiment, be equipped with location structure between collector and the end cover board, when equipment collector and end cover board, location structure has played fine positioning action, prevents that the collector from taking place the dislocation with the end cover board in the equipment in-process, and then appear in the direction of height of casing, and the utmost point ear connecting portion of collector has sheltered from explosion-proof valve, influences gas and in time lets out.

According to some embodiments of the application, the end cap connection is cylindrical; the current collector comprises at least three tab connection portions, each tab connection portion is connected to the outer peripheral surface of the end cover connection portion, and extends from the end cover connection portion along the radial direction of the end cover connection portion.

According to some embodiments of the present application, an included angle is formed between every two adjacent tab connection portions along the circumferential direction of the end cover connection portion, and at least three included angles are equal.

In this application embodiment, at least three utmost point ear connecting portion all is connected with the end cover connecting portion, and is radial extension all around taking the end cover connecting portion as the center, so at least three utmost point ear connecting portion and end cover board butt have increased the atress face between collector and the end cover board, and the collector receives after the gas impact, is difficult to take place to rock for the end cover board more.

In addition, the current collector of the embodiment of the application is of a symmetrical structure, and the geometric center of the current collector is located on the axis of the end cover connecting part. Then, after the current collector is impacted by the gas, the position distribution of the acting force of the end cover plate on the current collector is more uniform, and the end cover plate cannot be deformed locally.

According to some embodiments of the present application, the first projection includes two oppositely disposed long sides, and a width is between the two long sides;

the second projection is elliptical, the long axis of the ellipse is perpendicular to the radial direction of the end cover connecting part, and the distance between two vertexes formed by intersecting the long axis of the ellipse and the ellipse is L, wherein W is smaller than L.

In this embodiment of the present application, W is smaller than L, so even in the height direction of the case, the tab connection portion of the current collector shields the explosion-proof valve, the explosion-proof valve is not completely shielded, and gas can be discharged from a portion of the explosion-proof valve that is not shielded by the tab connection portion.

According to some embodiments of the present application, the end cap plate is provided with a connecting hole penetrating the first surface and the second surface;

each tab connection part is provided with a top surface facing the end cover plate, and at least three top surfaces are arranged in a coplanar manner and are abutted against the first surface;

the end cover connecting part comprises a base part and an inserting part connected with the base part, at least three tab connecting parts are connected with the base part, and the inserting part is convexly arranged on a plane formed by at least three top surfaces and is inserted into the connecting hole.

According to some embodiments of the present application, the current collector further comprises at least three first reinforcing structures;

along the circumferential direction of the end cover connecting part, one first reinforcing structure is connected between every two adjacent tab connecting parts;

wherein, in the direction of height of the housing, one of at least three first reinforcing structures corresponds to the explosion-proof valve, and the first reinforcing structure has a third projection on the first surface, the third projection at least partially overlapping the second projection.

In this application embodiment, through being connected with first additional strengthening between two adjacent tab connecting portions, can improve the holistic intensity of collector, avoid taking place deformation between tab connecting portion self and tab connecting portion and the end cover connecting portion.

According to some embodiments of the application, each of the first reinforcing structures comprises:

at least two first reinforcing ribs arranged side by side along the radial direction of the end cover connecting part; two ends of each first reinforcing rib are respectively connected with two adjacent lug connection parts; and

at least one second reinforcing rib extends along the radial direction of the end cover connecting part, and one second reinforcing rib is arranged between two adjacent first reinforcing ribs.

According to some embodiments of the application, each of the first ribs is arcuate and partially surrounds the end cap connection.

According to some embodiments of the present application, the first reinforcing structure has a third surface facing the end cap plate and a fourth surface disposed opposite the third surface; the first reinforcing structure is also provided with an exhaust structure penetrating through the third surface and the fourth surface;

a cavity is formed between the third surface and the first surface of the end cover plate, the exhaust structure is communicated with the cavity, and the exhaust structure of one of the first reinforcing structures is communicated with the air leakage hole.

In an embodiment of the present application, the first reinforcing structure is not in contact with the first surface of the end cap plate, but rather a cavity is formed between the third surface of the first reinforcing structure and the first surface of the end cap plate, and wherein the vent structure of one of the first reinforcing structures is in communication with the vent hole. The gas generated in the battery can enter the cavity through the exhaust structure, and the cavity can temporarily store the gas for reducing the impact force of the gas.

According to some embodiments of the present application, the exhaust structure comprises:

The exhaust holes are formed in the first reinforcing ribs and/or the second reinforcing ribs;

and the exhaust channel is arranged between two adjacent first reinforcing ribs in the radial direction of the end cover connecting part, and the exhaust channel is arranged between the first reinforcing rib closest to the end cover connecting part and two adjacent tab connecting parts in at least two first reinforcing ribs.

According to some embodiments of the present application, the tab connection part is provided with a top surface facing the end cover plate and a bottom surface disposed opposite to the top surface, the top surface is abutted against the first surface of the end cover plate, and the bottom surface is electrically connected with the electrode assembly;

the tab connection portion is recessed from the top surface toward the bottom surface to form a groove.

In this embodiment of the present application, since the tab connection portion is recessed from the top surface toward the bottom surface to form a groove, a thinned region is formed between the top surface and the bottom surface, and welding energy is easier to realize the tab welding connection between the tab connection portion and the electrode assembly through the thinned region.

According to some embodiments of the present application, the end of the tab connection portion, which is close to the housing, has an end surface, and the end surfaces are respectively connected with the top surface and the bottom surface;

The groove penetrates the end face.

In this application embodiment, the recess runs through the terminal surface of utmost point ear connecting portion, and the gas that so produces in the battery accessible utmost point ear connecting portion's terminal surface and the clearance between the inner peripheral surface of casing get into in the recess, and the effect of reposition of redundant personnel gas can be played to three recess of at least three utmost point ear connecting portion, avoids a large amount of gas unable discharge through the explosion-proof valve and appear the battery explosion.

According to some embodiments of the present application, the end cap plate is recessed from the first surface in the direction of the second surface to form a first countersink having a first channel floor;

the end cover plate is recessed from the bottom of the first groove towards the direction of the second surface to form a second sinking groove, and the second sinking groove is provided with a second groove bottom surface;

the air leakage hole penetrates through the bottom surface of the second groove, and the explosion-proof valve is accommodated in the second sinking groove and is attached to the bottom surface of the second groove.

In this application embodiment, explosion-proof valve holds in the second subsidence inslot, and with the laminating of the second tank bottom face of second subsidence inslot for explosion-proof valve can not bulge in the first surface of end cover plate, can not occupy the volume of the direction of height of battery, is favorable to improving battery energy density.

According to some embodiments of the present application, the end cap assembly further comprises a second reinforcing structure connected to the first groove bottom surface and disposed around the outer periphery of the second sink groove.

In this application embodiment, through setting up second additional strengthening, second additional strengthening connects in first groove bottom surface, and encircles and set up in the periphery of second subsidence groove, has compensatied the end cover board and has owing to set up the structural strength that first subsidence groove and second subsidence groove caused and reduce.

According to some embodiments of the present application, the second reinforcing structure comprises:

the reinforcing protrusions are arranged on the bottom surface of the first groove in a protruding mode, and the reinforcing protrusions are sequentially arranged along the periphery of the second sinking groove; and

and the connecting ribs are connected with a plurality of the reinforcing bulges in series.

According to some embodiments of the present application, the end cap assembly further comprises a protective sheet;

the end cover plate is recessed from the second surface towards the direction of the first surface to form a third sinking groove, the third sinking groove is provided with a third groove bottom surface, and the air leakage hole penetrates through the third groove bottom surface;

the protection sheet is accommodated in the third sinking groove and attached to the bottom surface of the third groove.

The electric equipment comprises any one of the energy storage devices, and the energy storage devices supply power for the electric equipment.

Drawings

Fig. 1 is a schematic diagram illustrating a configuration of a household energy storage system according to an exemplary embodiment.

Fig. 2 is a schematic structural view of a cylindrical unit cell according to a first embodiment of the present application.

Fig. 3 is an exploded view of fig. 2.

Fig. 4 is a schematic bottom view of a current collector and end cap assembly assembled according to a first embodiment of the present application, wherein the bottom view is from the first surface to the second surface of the end cap plate.

Fig. 5 is a schematic side view of a header and end cap assembly shown assembled according to a first embodiment of the present application.

Fig. 6 is a schematic view of the current collector of fig. 3.

Fig. 7 is an exploded schematic view of an end cap assembly according to a first embodiment of the present application.

Fig. 8 is a partial enlarged view at X1 in fig. 7.

Fig. 9 is a partial enlarged view at X2 in fig. 3.

Fig. 10 is a schematic diagram showing a positional relationship between a first projection and a second projection according to a first embodiment of the present application.

Fig. 11 is a schematic side view of an end cap plate assembled with a current collector according to a second embodiment of the present application.

Wherein reference numerals are as follows:

1. an energy storage device;

2. an electric energy conversion device;

3. user load;

100. a housing; 101. an opening; 110. a receiving chamber;

300. an electrode assembly;

500. an end cap assembly; 510. an end cover plate; 511. a first surface; 512. a second surface; 513. a vent hole; 514. a connection hole; 515. a first sink; 515a, first groove bottom surface; 516. a second sink tank; 516a, second groove bottom surface; 517. a third sink tank; 517a, third groove bottom surface; 520. an explosion-proof valve; 530. a second reinforcing structure; 531. reinforcing the protrusion; 532. a connecting rib; 540. a protective sheet;

700. a current collector; 710. an end cap connection portion; 711. a base; 712. an insertion section; 720. a tab connection part; 721. a top surface; 722. a bottom surface; 723. a groove; 724. an end face; 730. a first reinforcing structure; 731. a first reinforcing rib; 732. a second reinforcing rib; 733. a third surface; 734. a fourth surface; 735. an exhaust structure; 735a, exhaust holes; 735b, an exhaust passage; 740. a cavity; 751. a long side;

900. a positioning structure; 910. positioning the bulge; 920. a positioning groove;

s1, first projection; s2, second projection; s3, third projection;

α1/α2/α3, included angle;

w, width;

l, distance;

AB. A long axis.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus detailed descriptions thereof will be omitted.

Because of the strong timeliness and space properties of energy sources required by people, in order to reasonably utilize the energy sources and improve the utilization rate of the energy, one energy form needs to be stored by one medium or equipment and then is converted into another energy form, and then is released in a specific energy form based on future application requirements. As is well known, to achieve the great goal of carbon neutralization, green energy is currently mainly used to replace fossil energy so as to achieve the purpose of generating green electric energy.

The existing green energy mainly comprises light energy, wind energy, water potential and the like, and the problems of strong intermittence and large fluctuation of the light energy, the wind energy and the like generally exist, so that the voltage of a green power grid is unstable (insufficient electricity is used in a peak and too much electricity is used in a valley), and the unstable voltage can cause damage to the electric power, so that the problem of 'wind abandoning and light abandoning' is possibly caused by insufficient electricity demand or insufficient power grid receiving capability.

To solve the problem of insufficient power demand or insufficient power grid acceptance, an energy storage device must be relied on. The energy storage device converts the electric energy into other forms of energy through physical or chemical means to store the energy, the energy stored by the energy storage device is converted into the electric energy to be released when needed, in short, the energy storage device is similar to a large-scale 'charge pal', when the light energy and the wind energy are sufficient, the electric energy is stored, and the stored electric energy is released when needed.

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 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. 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.

Taking a household energy storage scenario in user side energy storage as an example for illustration, fig. 1 shows a household energy storage system, which comprises an energy storage device 1 and an electric energy conversion device 2 (such as a photovoltaic panel), and a user load 3 (such as a street lamp, a household appliance, etc.), wherein the energy storage device 1 is a small energy storage box, and can be installed on an outdoor wall in a wall hanging manner. Specifically, the electric energy conversion device 2 may convert solar energy into electric energy at the time of low electricity price, store the electric energy by the energy storage device 1, and supply the electric energy to the consumer load 3 for use at the time of high electricity price or supply the electric energy to the consumer load 3 for use at the time of power failure/power outage of the power grid.

In combination with the above-mentioned case of energy storage by physical or electrochemical means, taking electrochemical energy storage as an example, the energy storage device 1 includes at least one group of chemical batteries, and chemical elements in the chemical batteries are used as an energy storage medium, so as to implement a charging and discharging process through chemical reaction or change of the energy storage medium. In short, the electric energy generated by light energy and wind energy is stored in at least one group of chemical batteries through chemical reaction or change of the energy storage medium, and when the use of external electric energy reaches a peak, the electric quantity stored in at least one group of chemical batteries is released for use through the chemical reaction or change of the energy storage medium, or is transferred to a place where the electric quantity is short for use.

The present embodiments provide an energy storage device 1, and the energy storage device 1 may be, but is not limited to, a single battery, a battery module, a battery pack, a battery system, and the like. For the single battery, it may be a lithium ion secondary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, etc., and the single battery may be a cylinder. When the energy storage device 1 is a single battery, it may be a square single battery or a cylindrical single battery. Next, the energy storage device 1 will be explained in detail using the energy storage device 1 as a cylindrical unit cell as an example.

As shown in fig. 2 and 3, the energy storage device 1 of the embodiment of the present application includes a case 100, an electrode assembly 300, an end cap assembly 500, and a current collector 700. The case 100 includes a receiving chamber 110 having an opening 101, the electrode assembly 300 is received in the receiving chamber 110, and the cap assembly 500 is coupled to the case 100 and closes the opening 101 of the receiving chamber 110. The current collector 700 is disposed in the receiving chamber 110 and is electrically connected with the cap assembly 500 and the electrode assembly 300, respectively.

It will be understood that the terms "comprising," "including," and "having," and any variations thereof, as used in the embodiments herein, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may alternatively include other steps or elements not listed or inherent to such process, method, article, or apparatus.

The housing 100 may have a cylindrical structure with an opening 101 at one end, where the energy storage device 1 includes an end cap assembly 500, and the end cap assembly 500 seals the opening 101. Of course, the housing 100 may also be a cylindrical structure having openings 101 at both ends, in which case the energy storage device 1 may include one end cap assembly 500 and one cover plate, or the energy storage device 1 may include two end cap assemblies 500, such that one end cap assembly 500 and one cover plate, or both end cap assemblies 500 can seal the two openings 101 of the housing 100, respectively.

The end cap assembly 500 may include, among other things, an end cap plate 510, an explosion proof valve 520, and a protective sheet 540. An end cap plate 510 is connected to the housing 100 and seals the opening 101 of the receiving cavity 110. Welding may be used for the connection of the end cap plate 510 to the housing 100. The shape of the end cap plate 510 is adapted to the shape of the opening 101. When the energy storage device 1 is a cylindrical unit cell, the end cap plate 510 has a disk shape.

The end cap plate 510 has a first surface 511 facing the electrode assembly 300 and a second surface 512 disposed opposite the first surface 511, and the end cap plate 510 is further provided with a vent hole 513 penetrating the first surface 511 and the second surface 512, and the explosion proof valve 520 closes the vent hole 513. The explosion-proof valve 520 is used to exhaust harmful gas generated in the receiving chamber 110 of the housing 100 to improve the safety of the energy storage device 1.

The end cap plate 510 is further provided with liquid injection holes (not shown) penetrating the first surface 511 and the second surface 512 of the end cap plate 510. After the cap assembly 500 seals the opening 101 of the receiving chamber 110, electrolyte may be injected into the receiving chamber 110 of the case 100 through the injection hole. And after the injection of the electrolyte is completed, the sealing piece can be used for sealing the electrolyte injection hole so as to avoid the leakage of the electrolyte. Wherein, to avoid the sealing member from jumping out of the pouring orifice, the second surface 512 of the end cover plate 510 may be welded with a cover plate (not shown in the figure) shielding the pouring orifice.

The electrode assembly 300 includes a positive electrode sheet, a negative electrode sheet, and a separator. The single cell mainly relies on metal ions to move between the positive plate and the negative plate to work. The positive plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the positive electrode current collector without the positive electrode active material layer protrudes out of the positive electrode current collector coated with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer is used as a positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate or the like. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the negative electrode current collector without the negative electrode active material layer protrudes out of the negative electrode current collector coated with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer is used as a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. The isolating film may be PP, PE, etc. In addition, the electrode assembly 300 may be a roll-to-roll structure or a lamination structure, and the embodiment of the present application is not limited thereto.

The positive and negative tabs may be located at the same end of the electrode assembly 300 (e.g., square unit cells) or at different ends of the electrode assembly 300 (e.g., cylindrical unit cells). When the positive electrode tab and the negative electrode tab are located at the same end of the electrode assembly 300, the second surface 512 of the end cover plate 510 may be convexly provided with a positive electrode post and a negative electrode post, and the positive electrode post is connected with the positive electrode tab, and the negative electrode post is connected with the negative electrode tab, so as to realize the output of the electric energy of the electrode assembly 300 through the positive electrode post and the negative electrode post. When the positive electrode tab and the negative electrode tab are respectively positioned at both ends of the electrode assembly 300, one of the positive electrode tab and the negative electrode tab is connected with the electrode post provided by the end cap assembly 500, and the other of the positive electrode tab and the negative electrode tab is connected with the bottom of the case 100 or the electrode post provided by the other end cap assembly 500. The pole connected with the positive pole lug is used as a positive pole, and the pole connected with the negative pole lug is used as a negative pole.

It should be noted that, the positive electrode tab of the electrode assembly 300 may be connected to the positive electrode column through one current collector 700, and the negative electrode tab of the electrode assembly 300 may be connected to the negative electrode column through the other current collector 700.

As shown in fig. 4 and 5, the current collector 700 includes an end cap connection part 710 and a tab connection part 720, the tab connection part 720 is connected with the end cap connection part 710, the end cap connection part 710 is electrically connected with the end cap plate 510, and the tab connection part 720 is electrically connected with a tab (positive or negative tab) of the electrode assembly 300.

Along the height direction D of the housing 100, the tab connection portion 720 has a first projection S1 on the first surface 511, and the explosion-proof valve 520 has a second projection S2 on the first surface 511, where the first projection S1 and the second projection S2 do not overlap.

In this embodiment of the present application, along the height direction D of the housing 100, the tab connection portion 720 has the first projection S1 on the first surface 511, the explosion-proof valve 520 has the second projection S2 on the first surface 511, and the first projection S1 and the second projection S2 do not overlap, so that in the height direction D of the housing 100, the tab connection portion 720 of the current collector 700 is staggered with the explosion-proof valve 520, and when the gas generated inside the energy storage device 1 impinges on the current collector 700, the tab connection portion 720 does not shield the explosion-proof valve 520, so that the gas can burst through the explosion-proof valve 520 and leak out in time, thereby avoiding the explosion of the energy storage device 1.

It should be noted that, the first projection S1 of the tab connection portion 720 on the first surface 511 of the end cover plate 510 and the second projection S2 of the explosion-proof valve 520 on the first surface 511 of the end cover plate 510 are both orthographic projections. That is, the projection lines of the first projection S1 and the second projection S2 are parallel projection lines, and the projection lines are parallel to the height direction D of the housing 100.

As shown in fig. 4 and 6, the current collector 700 includes at least three tab connection parts 720, and each of the at least three tab connection parts 720 is connected to the end cap connection part 710 and radially extends from the end cap connection part 710.

In this embodiment, at least three tab connection portions 720 are all connected with the end cover connection portion 710, and radially extend around the end cover connection portion 710, so that the at least three tab connection portions 720 are abutted to the end cover plate 510, the stress surface between the current collector 700 and the end cover plate 510 is increased, and the current collector 700 is less prone to shaking relative to the end cover plate 510 after being impacted by gas.

Of course, in other embodiments, the number of tab connection portions 720 may be one, two, four, five, etc.

Further, the end cap connection part 710 is cylindrical, and each tab connection part 720 is connected to the outer circumferential surface of the end cap connection part 710 and extends in the radial direction of the end cap connection part 710. Along the circumferential direction of the end cover connection portion 710, an included angle is formed between every two adjacent tab connection portions 720, and at least three included angles are equal to each other. As such, the current collector 700 of the present embodiment is of a symmetrical structure, and the geometric center of the current collector 700 is located on the axis of the end cap connection 710. Then, when the current collector 700 is impacted by the gas, the positions of the end cover plate 510 subjected to the acting force of the current collector 700 are distributed more uniformly, and the end cover plate 510 is not deformed locally.

In this embodiment, the number of tab connection portions 720 is three, and along the circumferential direction of the end cap connection portion 710, two adjacent tab connection portions 720 form included angles α1, α2, and α3, respectively, with α1=α2=α3=120°.

As shown in fig. 3 and 6, the end cap plate 510 is provided with a connection hole 514, and the connection hole 514 penetrates the first surface 511 and the second surface 512. Each tab connection 720 has a top surface 721 facing the end cap plate 510, the top surface 721 abutting the first surface 511 of the end cap plate 510. At least three top surfaces 721 are disposed coplanar and abut the first surface 511. The end cap connection part 710 includes a base part 711 and an insertion part 712 connected to the base part 711, and at least three tab connection parts 720 are connected to the base part 711, and the insertion part 712 is protruded on a plane formed by at least three top surfaces 721 and inserted into the connection hole 514.

As shown in fig. 6, current collector 700 also includes at least three first reinforcing structures 730. A first reinforcing structure 730 is connected between each adjacent two tab connection portions 720 along the circumferential direction of the end cap connection portion 710.

As shown in fig. 4, each first reinforcing structure 730 has a third projection S3 on the first surface 511 of the end cap plate 510 in the height direction D of the housing 100, wherein one of the third projections S3 at least partially overlaps the second projection S2.

In this embodiment, the first reinforcing structure 730 is connected between two adjacent tab connection portions 720, so that the overall strength of the current collector 700 can be improved, and deformation of the tab connection portions 720 and between the tab connection portions 720 and the end cover connection portions 710 can be avoided.

It should be noted that, the third projection S3 of the first reinforcing structure 730 on the first surface 511 of the end cover plate 510 is also an orthographic projection.

As shown in fig. 6, each first reinforcing structure 730 includes at least two first reinforcing ribs 731 and at least one second reinforcing rib 732. At least two first reinforcing ribs 731 are arranged side by side in the radial direction of the end cap connection part 710, and both ends of each first reinforcing rib 731 are respectively connected to the adjacent two tab connection parts 720. At least one second reinforcing rib 732 extends in the radial direction of the end cap connection portion 710, and one second reinforcing rib 732 is provided between two adjacent first reinforcing ribs 731.

In one embodiment, each of the first reinforcing ribs 731 is arc-shaped and partially surrounds the end cap connection 710. Of course, in other embodiments, the first stiffener 731 may be shaped otherwise, for example, the first stiffener 731 may be linear.

As an example, each first reinforcing structure 730 includes at least two second reinforcing ribs 732 and at least two second reinforcing ribs 732, the at least two second reinforcing ribs 732 being disposed co-linearly along the radial direction of the end cap connection 710.

In the present embodiment, each first reinforcing structure 730 includes three first reinforcing ribs 731 and two second reinforcing ribs 732. The three first reinforcing ribs 731 are each arc-shaped and are arranged side by side in the radial direction of the end cover connecting portion 710. A second reinforcing rib 732 is disposed between two adjacent first reinforcing ribs 731, and the two second reinforcing ribs 732 are disposed in line along the radial direction of the end cap connection portion 710.

As shown in fig. 5 and 6, the first reinforcing structure 730 has a third surface 733 facing the end cover 510 and a fourth surface 734 disposed opposite the third surface 733. The first reinforcing structure 730 is also provided with a vent structure 735 extending through the third and fourth surfaces 733, 734. A cavity 740 is formed between the third surface 733 and the first surface 511 of the end cover 510, and the exhaust structure 735 is in communication with the cavity 740. The vent structure 735 of one of the first reinforcing structures 730 communicates with the bleed hole 513.

In the present embodiment, the first reinforcing structure 730 does not contact the first surface 511 of the end cap plate 510, but rather forms a cavity 740 between the third surface 733 of the first reinforcing structure 730 and the first surface 511 of the end cap plate 510, and the vent structure 735 of one of the first reinforcing structures 730 is in communication with the vent hole 513. Gas generated within the cell may enter the cavity 740 through the venting structure 735, and the cavity 740 may be capable of temporarily storing gas for reducing the impact force of the gas.

It should be noted that, in the embodiment of the present application, a side surface of the part formed by connecting the at least two first reinforcing ribs 731 and the at least one second reinforcing rib 732 facing the end cover plate 510 forms a third surface 733, and a side surface of the part formed by connecting the at least two first reinforcing ribs 731 and the at least one second reinforcing rib 732 facing away from the end cover plate 510 forms a fourth surface 734.

As shown in fig. 6, the exhaust structure 735 includes an exhaust hole 735a and an exhaust passage 735b. The first reinforcing bead 731 and/or the second reinforcing bead 732 are provided with air discharge holes 735a. An exhaust passage 735b is provided between two adjacent first reinforcing ribs 731 in the radial direction of the end cap connection portion 710, and an exhaust passage 735b is provided between a first reinforcing rib 731 closest to the end cap connection portion 710 among the at least two first reinforcing ribs 731 and the adjacent two tab connection portions 720.

As shown in fig. 6, the tab connection portion 720 includes a top surface 721 facing the end cap plate 510 and a bottom surface 722 facing away from the top surface 721, the top surface 721 abuts against the end cap plate 510, and the bottom surface 722 is electrically connected to the electrode assembly 300. The tab connection portion 720 is recessed from the top surface 721 toward the bottom surface 722 to form a recess 723.

When the current collector 700 is electrically connected to the electrode assembly 300, the tab connection part 720 is welded to the tab of the electrode assembly 300, typically by welding. When welding is performed, the bottom face 722 of the tab connection part 720 faces the tab of the electrode assembly 300, and the welding tool is positioned on the top face 721 of the tab connection part 720. In the embodiment of the present application, since the tab connection portion 720 is recessed from the top surface 721 toward the bottom surface 722 to form a groove 723, a thinned region is formed between the top surface 721 and the bottom surface 722, and welding energy is easier to realize the welding connection between the tab connection portion 720 and the tab of the electrode assembly 300 through the thinned region.

Further, the end of the tab connection portion 720 near the housing 100 has an end face 724, the end face 724 is connected to the top face 721 and the bottom face 722, respectively, and the groove 723 penetrates the end face 724.

In general, the end surface 724 of the tab connection portion 720 of the current collector 700 is not closely adhered to the inner peripheral surface of the case 100, but has a gap therebetween. In the embodiment of the present application, the groove 723 penetrates the end face 724 of the tab connection portion 720, so that the gas generated in the battery can enter the groove 723 through the gap between the end face 724 of the tab connection portion 720 and the inner peripheral surface of the housing 100, and the three grooves 723 of the at least three tab connection portions 720 can play a role in diverting the gas, so as to avoid the occurrence of explosion of the battery due to the centralized generation of a large amount of gas in the energy storage device, which cannot be discharged through the explosion-proof valve 520.

It can be understood that in the embodiment of the present application, the tab connection portion 720 is recessed from the top surface 721 toward the bottom surface 722 to form a groove 723, and the groove 723 divides the top surface 721 of the tab connection portion 720 into two sub-surfaces 721a, and each sub-surface 721a is connected to the outer peripheral surface of the end cap connection portion 710.

As shown in fig. 7 and 8, end cap plate 510 is recessed from first surface 511 toward second surface 512 to form a first sinker 515, first sinker 515 having a first slot bottom surface 515a. The end cap plate 510 is recessed from the first groove bottom surface 515a toward the second surface 512 to form a second countersink 516, the second countersink 516 having a second groove bottom surface 516a. The air leakage hole 513 penetrates through the second groove bottom surface 516a, and the explosion-proof valve 520 is accommodated in the second sinking groove 516 and is attached to the second groove bottom surface 516a.

In this embodiment, the explosion-proof valve 520 is accommodated in the second sinking groove 516 and is attached to the second groove bottom 516a of the second sinking groove 516, so that the explosion-proof valve 520 does not protrude from the first surface 511 of the end cover plate 510, and does not occupy the volume of the battery in the height direction D, which is beneficial to improving the energy density of the battery.

The end cap assembly 500 further includes a second reinforcing structure 530, the second reinforcing structure 530 being coupled to the first groove bottom surface 515a and disposed around the outer circumference of the second sink groove 516.

In the embodiment of the present application, by providing the second reinforcing structure 530, the second reinforcing structure 530 is connected to the bottom surface 515a of the first groove and surrounds the periphery of the second sinking groove 516, so as to compensate for the reduced structural strength of the end cover plate 510 caused by the arrangement of the first sinking groove 515 and the second sinking groove 516.

As shown in fig. 8, the second reinforcing structure 530 includes a plurality of reinforcing protrusions 531 and connection ribs 532. The plurality of reinforcing protrusions 531 are protruded at the first groove bottom surface 515a, and the plurality of reinforcing protrusions 531 are sequentially arranged along the outer circumference of the second sink groove 516. The connection rib 532 is connected in series with a plurality of reinforcing protrusions 531.

As shown in fig. 3 and 9, the end cap assembly 500 further includes a protective sheet 540. The end cover plate 510 is recessed from the second surface 512 toward the first surface 511 to form a third sinking groove 517, the third sinking groove 517 has a third groove bottom surface 517a, and the air leakage hole 513 penetrates the third groove bottom surface 517a. The protection sheet 540 is accommodated in the third sinking groove 517 and is attached to the bottom surface 517a of the third groove.

Further, a surface of the protective sheet 540 facing away from the third groove bottom surface 517a is flush with the second surface 512 of the end cover plate 510.

As shown in fig. 10, the first projection S1 is substantially rectangular, and the first projection S1 includes two long sides 751, and a width W is provided between the two long sides 751. The second projection S2 has an elliptical shape, a major axis AB of the ellipse is perpendicular to a radial direction of the end cap connection portion 710, and a distance between two vertices (a, B) formed by intersecting the major axis AB of the ellipse and the ellipse is L, wherein W is smaller than L.

It will be appreciated that the major axis AB of an ellipse is the longest line segment that can be obtained by connecting two points on the ellipse.

In the embodiment of the present application, W is smaller than L, so even if the tab connection portion 720 of the current collector 700 shields the explosion-proof valve 520 in the height direction D of the case 100, the explosion-proof valve 520 is not completely shielded, and gas can be discharged from a portion of the explosion-proof valve 520 not shielded by the tab connection portion 720.

Of course, in other embodiments, the shape of the second projection S2 may also be circular. When the shape of the second projection S2 is circular, the width W is smaller than the diameter of the circular shape.

As shown in fig. 11, the end cap plate 510 and the current collector 700 of the second embodiment are the same as those of the first embodiment, and are not described in detail, except that:

A positioning structure 900 is further provided between the current collector 700 and the end cap plate 510, and the positioning structure 900 includes a positioning protrusion 910 and a positioning groove 920. The positioning protrusion 910 is provided to one of the current collector 700 and the end cap plate 510, the positioning groove 920 is provided to the other of the current collector 700 and the end cap plate 510, and the positioning protrusion 910 is inserted into the positioning groove 920.

In this embodiment of the application, a positioning structure 900 is disposed between the current collector 700 and the end cover plate 510, when the current collector 700 and the end cover plate 510 are assembled, the positioning structure 900 plays a good role in positioning, so that the current collector 700 and the end cover plate 510 are prevented from being misplaced in the assembly process, and then appear in the height direction D of the housing 100, and the tab connection portion 720 of the current collector 700 shields the explosion-proof valve 520, so that the gas is influenced to leak out in time.

In the embodiment of the present application, the positioning protrusion 910 is disposed on the current collector 700, and the positioning groove 920 is disposed on the end cover plate 510. Further, the positioning protrusion 910 is protruding from the third surface 733 of the first reinforcing structure 730, the positioning groove 920 is recessed from the first surface 511 to the second surface 512 of the end cover plate 510, and the opening 101 of the positioning groove 920 faces the current collector 700.

The embodiment of the application also provides electric equipment, which comprises the energy storage device 1 in any embodiment, and the energy storage device 1 supplies power for the electric equipment. Because the energy storage device 1 of any of the above embodiments is included, the electric equipment of the embodiment of the present application has all the advantages and beneficial effects of any of the above embodiments, and will not be described herein again.

The electric equipment can be in various forms, for example, the electric equipment can be energy storage equipment, a vehicle, an energy storage container and the like.

The electric equipment can also be mobile phones, portable equipment, notebook computers, battery cars, ships, spacecraft, electric toys, electric tools and the like. Further, for example, the spacecraft may include an airplane, a rocket, a space vehicle, a spacecraft, and the like, and the electric toy may include a fixed or mobile electric toy such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like, and the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, and an electric planer.

It is to be understood that the various embodiments/implementations provided herein may be combined with each other without conflict and are not illustrated herein.

In the examples of the application, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more, unless expressly defined otherwise. The terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; "coupled" may be directly coupled or indirectly coupled through intermediaries. The specific meaning of the terms in the examples of application will be understood by those of ordinary skill in the art as the case may be.

In the description of the application embodiments, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," and the like indicate an orientation or a positional relationship based on that shown in the drawings, and are merely for convenience in describing the application embodiments and simplifying the description, and do not indicate or imply that the devices or units to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the application embodiments.

In the description of the present specification, the terms "one embodiment," "some embodiments," "particular embodiments," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of an application embodiment. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above is only a preferred embodiment of the application embodiment, and is not intended to limit the application embodiment, and various modifications and changes may be made to the application embodiment by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the application should be included in the protection scope of the embodiments of the application.

Claims

1. An energy storage device, comprising:

a housing including a receiving chamber having an opening;

an electrode assembly accommodated in the accommodation chamber;

an end cap assembly comprising an end cap plate and an explosion-proof valve, the end cap plate being connected to the housing and closing the opening; the end cover plate is provided with a first surface facing the electrode assembly and a second surface arranged opposite to the first surface, the end cover plate is also provided with a gas leakage hole penetrating through the end cover plate, and the explosion-proof valve seals the gas leakage hole; and

the current collector is arranged in the accommodating cavity and comprises an end cover connecting part and a lug connecting part connected with the end cover connecting part, the end cover connecting part is electrically connected with the end cover plate, and the lug connecting part is electrically connected with the electrode assembly;

the explosion-proof valve is characterized in that the tab connection part is provided with a first projection on the first surface along the height direction of the shell, the explosion-proof valve is provided with a second projection on the first surface, and the first projection and the second projection are not overlapped.

2. The energy storage device of claim 1, wherein a positioning structure is further provided between the current collector and the end cap plate, the positioning structure comprising:

3. The energy storage device of claim 1, wherein the end cap connection is cylindrical;

the current collector comprises at least three tab connection portions, each tab connection portion is connected to the outer peripheral surface of the end cover connection portion, and extends from the end cover connection portion along the radial direction of the end cover connection portion.

4. The energy storage device of claim 3, wherein an included angle is formed between every two adjacent tab connection portions along the circumferential direction of the end cap connection portions, and at least three of the included angles are equal.

5. The energy storage device of claim 3, wherein said first projection includes two oppositely disposed long sides having a width therebetween;

6. The energy storage device of claim 3, wherein the end cap plate is provided with attachment holes extending through the first and second surfaces;

7. The energy storage device of claim 3, wherein said current collector further comprises at least three first reinforcing structures;

8. The energy storage device of claim 7, wherein each of said first reinforcing structures comprises:

9. The energy storage device of claim 8, wherein each of the first ribs is arcuate and partially surrounds the end cap connection.

10. The energy storage device of claim 8, wherein the first reinforcing structure has a third surface facing the end cap plate and a fourth surface disposed opposite the third surface; the first reinforcing structure is also provided with an exhaust structure penetrating through the third surface and the fourth surface;

11. The energy storage device of claim 10, wherein the exhaust structure comprises:

12. The energy storage device of claim 1, wherein the tab connection portion is provided with a top surface facing the end cap plate and a bottom surface disposed opposite the top surface, the top surface abutting the first surface of the end cap plate, the bottom surface being electrically connected to the electrode assembly;

13. The energy storage device of claim 12, wherein an end of said tab connection portion adjacent said housing has an end face, said end face being connected to said top and bottom faces, respectively;

the groove penetrates the end face.

14. The energy storage device of claim 1, wherein the end cap plate is recessed from the first surface in a direction of the second surface to form a first sink having a first sink bottom surface;

15. The energy storage device of claim 14, wherein the end cap assembly further comprises a second reinforcing structure connected to the first channel bottom surface and disposed around the periphery of the second sink channel.

16. The energy storage device of claim 15, wherein the second reinforcing structure comprises:

17. The energy storage device of claim 1, wherein the end cap assembly further comprises a protective sheet;

18. A powered device comprising an energy storage device according to any one of claims 1 to 17, the energy storage device powering the powered device.