Energy storage device and energy storage system

Abstract

The utility model discloses an energy storage device and an energy storage system.The energy storage device comprises a shell, a naked battery cell, an end cover assembly and a current collecting disc, the shell is provided with an inner cavity and an opening communicated with the inner cavity, the naked battery cell is arranged in the inner cavity, the end cover assembly comprises an end cover plate and a pole structure, the end cover plate is arranged at the opening in a sealed mode, and the pole structure is arranged in the shell; the end cover plate is provided with a first pole hole penetrating in the thickness direction of the end cover plate, the pole structure penetrates through the first pole hole, the current collecting plate is located between the end cover assembly and the naked battery cell, the current collecting plate and the end cover assembly are arranged in a split mode, the current collecting plate comprises a tab connecting part, a pole connecting part and a bent part connected between the tab connecting part and the pole connecting part, and the pole connecting part is connected with the bent part. The tab connecting part is connected with a tab of the naked battery cell, and the bending part is bent once, so that the pole connecting part is bent towards one side of the end cover assembly, and the pole connecting part is connected with the pole structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to an energy storage device and an energy storage system. BACKGROUND

[0002] In related technologies, in order to ensure the performance of the battery, a current collecting disc is usually used to realize the electrical connection between the tab of the bare battery cell and the pole of the end cover.

[0003] The current collecting disc commonly seen on the market is mostly a bent current collecting disc, especially a "Z" shaped current collecting disc which is bent twice. During assembly, the current collecting disc and the pole of the end cover are usually welded first to form an integrated structure, and then the current collecting disc is welded on the bare battery cell and the end cover is assembled on the shell.

[0004] However, in the above assembly process, the presence of the end cover makes it inconvenient for the equipment to position and clamp the bending area of the current collecting disc. Moreover, the current collecting disc needs to be bent twice, and the bending deviation increases after two bending processes, which makes it difficult to center the current collecting disc when it is assembled and welded on the bare battery cell, thereby reducing the assembly efficiency of the battery. CONTENT OF THE INVENTION

[0005] The present application discloses an energy storage device and an energy storage system, which can be folded to one side of the end cover assembly through one bending process to be fixedly connected with the pole structure, thereby solving the problem of difficult centering of the current collecting disc into the shell, and facilitating the assembly efficiency.

[0006] To achieve the above purpose, in a first aspect, the present application discloses an energy storage device, which comprises:

[0007] a shell having an inner cavity and an opening communicating with the inner cavity;

[0008] a bare battery cell built in the inner cavity;

[0009] an end cover assembly comprising an end cover plate and a pole structure, the end cover plate being sealingly arranged at the opening, and the end cover plate being provided with a first pole hole penetrating through the thickness direction thereof, and the pole structure being arranged in the first pole hole; and

[0010] The current collector plate is located between the end cover assembly and the bare battery cell, and the current collector plate and the end cover assembly are separately arranged. The current collector plate comprises a tab connecting portion, a post connecting portion, and a bending portion connected between the tab connecting portion and the post connecting portion. The tab connecting portion is connected with the tab of the bare battery cell. The bending portion is bent once, so that the post connecting portion is folded to one side of the end cover assembly. The post connecting portion is connected with the post structure.

[0011] In the energy storage device provided in the present application, the current collector plate and the end cover assembly are separately arranged. The post connecting portion of the current collector plate is first welded with the tab of the bare battery cell. The post connecting portion of the current collector plate is folded to one side of the end cover assembly through one bending of the bending portion of the current collector plate, and then the post connecting portion of the current collector plate is penetration welded with the post structure of the end cover assembly. In the above assembly process, after the tab connecting portion of the current collector plate is welded with the tab of the bare battery cell, the bare battery cell can be pressed by the equipment to facilitate the welding of the post structure. The post connecting portion of the current collector plate can be folded to one side of the end cover assembly through one bending of the bending portion of the current collector plate, so as to facilitate the penetration welding of the post connecting portion and the post structure, reduce the number of bending, and improve the bending accuracy. Thus, the problem of difficulty in centering of the current collector plate into the shell is solved, and the assembly efficiency of the energy storage device is improved.

[0012] In addition, since the bending portion of the current collector plate is only bent once, the current collector plate is no longer in a Z-shaped structure, the length of the current collector plate is shortened, the occupied space of the current collector plate is reduced, and the internal space of the energy storage device is saved.

[0013] As an optional implementation, in the embodiment of the first aspect of the present application, the end cover assembly further comprises a lower plastic, which is arranged on the side of the end cover plate facing the current collector plate. The lower plastic is provided with a second post hole penetrating in the thickness direction thereof, and the second post hole is in communication with the first post hole. The post structure is sequentially arranged in the second post hole and the first post hole.

[0014] The surface of the lower plastic away from the end cover plate is provided with a protruding portion, and a receiving space is formed between the protruding portion and the lower plastic. The post connecting portion and the bending portion are located in the receiving space, and the tab connecting portion is abutted by the protruding portion.

[0015] In this way, the protruding portion can press the tab connecting portion of the current collector plate to press the bare battery cell, so as to avoid the shaking of the bare battery cell inside the shell, and ensure the safety of the energy storage device.

[0016] As an optional implementation, in the embodiment of the first aspect of the present application, the end cover assembly further comprises:

[0017] An upper plastic is arranged on a side of the end cover plate away from the current collector plate, and the upper plastic is provided with a third pole post hole penetrating in a thickness direction thereof, the third pole post hole being in communication with the first pole post hole, wherein the pole post structure is arranged in the first pole post hole and the third pole post hole in sequence, a first exhaust passage is arranged between the upper plastic and the end cover plate, the first exhaust passage is connected with the first pole post hole, and / or a second exhaust passage is arranged between a hole wall surface of the third pole post hole and an outer circumferential surface of the pole post structure, the second exhaust passage being in communication with the first pole post hole; and

[0018] A sealing ring is sleeved on the outer circumference of the pole post structure, and is located between the outer circumferential surface of the pole post structure and the hole wall surface of the first pole post hole, the sealing ring abutting against the upper plastic.

[0019] In this way, helium detection can be performed by using the first exhaust passage and / or the second exhaust passage to detect the sealing property of the sealing ring, that is, if helium is detected during helium detection, it indicates that helium in the shell can be discharged to the first exhaust passage and / or the second exhaust passage through the first pole post hole and be detected, which indicates that the sealing ring does not effectively seal the gap between the outer circumferential surface of the pole post structure and the hole wall surface of the first pole post hole; on the contrary, if helium is not detected during helium detection, it indicates that helium in the shell cannot be discharged to the first exhaust passage and / or the second exhaust passage through the first pole post hole, and thus cannot be detected, which indicates that the sealing ring effectively seals the gap between the outer circumferential surface of the pole post structure and the hole wall surface of the first pole post hole, thereby detecting the sealing property of the sealing ring.

[0020] As an optional implementation, in the embodiment of the first aspect of the present application, the upper plastic has a first surface and a second surface opposite in the thickness direction thereof, a chamfer structure is arranged at a connection between the first surface and the hole wall surface of the third pole post hole, and / or a chamfer structure is arranged at a connection between the second surface and the hole wall surface of the third pole post hole.

[0021] In this way, a chamfer structure is arranged at a position where the upper plastic contacts the pole post structure, during the pressing and pressing process of the riveting mode for fixing the pole post structure, stress is formed in the inside of the sealing ring, the arrangement of the chamfer structure enables the sealing ring to release the excess amount to the gap between the chamfer structure and the pole post structure through stress when the sealing ring is pressed, thereby increasing the sealing effect of the sealing ring on the pole post structure and the upper plastic; at the same time, the stress of the sealing ring can be partially released to protect the end cover plate and the sealing ring.

[0022] In addition, when the hole wall surface of the third post hole and the outer circumferential surface of the post structure are spaced apart to form the second exhaust passage, in the pressing process in which the post structure is riveted, even if the post structure expands, due to the chamfer structure, the contact between the upper plastic and the post structure can be reduced, and the second exhaust passage is prevented from being blocked, so that the sealing effectiveness of the sealing ring cannot be detected, and the chamfer structure can prevent false sealing.

[0023] As an optional embodiment, in the embodiment of the first aspect of the application, when the first exhaust passage is arranged between the upper plastic and the end cover plate;

[0024] The surface of the upper plastic facing the end cover plate is provided with an annular protrusion, the annular protrusion is arranged around the periphery of the third post hole, the annular protrusion is located in the first post hole and abuts against the sealing ring, and the post structure is sequentially arranged in the first post hole, the annular protrusion and the third post hole.

[0025] The outer circumferential surface of the annular protrusion is recessed to form a gap away from the hole wall surface of the first post hole, and the gap is in communication with the first exhaust passage.

[0026] In this way, by arranging the gap of the first exhaust passage on the outer circumferential surface of the annular protrusion of the upper plastic extending into the first post hole, even if the post structure expands and presses the annular protrusion tightly in the process of riveting the post structure, so that the outer circumferential surface of the annular protrusion abuts against the hole wall surface of the first post hole, due to the gap, there is still a gap between the outer circumferential surface of the annular protrusion and the hole wall surface of the first post hole to communicate with the first exhaust passage, which ensures that when the sealing ring does not effectively seal between the hole wall surface of the first post hole and the outer circumferential surface of the post structure, helium can enter the first exhaust passage through the gap and be detected, thereby ensuring that the sealing performance of the sealing ring can be effectively detected, and further ensuring the sealing performance of the sealing ring.

[0027] As an optional embodiment, in the embodiment of the first aspect of the application, the annular protrusion has an abutting surface abutting against the sealing ring, and a chamfer structure is arranged at the connection between the abutting surface and the hole wall surface of the third post hole.

[0028] Thus, on the basis of the positioning effect of the cooperation of the annular protrusion and the first pole column hole, the chamfer structure is arranged at the position where the annular protrusion contacts the pole column structure. In the pressing and riveting process of fixing the pole column structure by extrusion, stress is formed in the inside of the sealing ring. The arrangement of the chamfer structure enables the sealing ring to release the excess amount to the gap between the chamfer structure and the pole column structure through stress when the sealing ring is under pressure, thereby increasing the sealing effect of the sealing ring on the pole column structure and the upper plastic.

[0029] In addition, when the second exhaust passage is arranged between the hole wall surface of the third pole column hole and the outer circumferential surface of the pole column structure, even if the pole column structure expands in the pressing and riveting process of the pole column structure, the contact between the annular protrusion and the pole column structure can be reduced due to the arrangement of the chamfer structure, thereby avoiding the blocking of the second exhaust passage and the situation that the sealing effectiveness of the sealing ring cannot be detected, so that the chamfer structure can avoid false sealing.

[0030] As an optional implementation, in the embodiment of the first aspect of the present application, when the second exhaust passage is arranged between the hole wall surface of the third pole column hole and the outer circumferential surface of the pole column structure;

[0031] The end cover assembly further comprises a pressing block, the pressing block is arranged on the side of the upper plastic away from the end cover plate, and the pressing block is provided with a fourth pole column hole penetrating through the thickness direction thereof, the fourth pole column hole is in communication with the third pole column hole, and the pole column structure is sequentially arranged in the first pole column hole, the third pole column hole and the fourth pole column hole.

[0032] A third exhaust passage is arranged between the pressing block and the upper plastic, the third exhaust passage is in communication with the second exhaust passage, and / or a fourth exhaust passage is arranged between the hole wall surface of the fourth pole column hole and the outer circumferential surface of the pole column structure, the fourth exhaust passage is in communication with the second exhaust passage.

[0033] Thus, when the sealing ring does not effectively seal the gap between the outer circumferential surface of the pole column structure and the hole wall surface of the first pole column hole, the channel for helium leakage is increased, and the helium can be smoothly leaked out to improve the accuracy of helium detection, so that whether the sealing ring is sealed well can be accurately detected, and the sealing effect of the sealing ring can be ensured.

[0034] As an optional implementation, in the embodiment of the first aspect of the present application, the surface of the pressing block facing the upper plastic is provided with an anti-fooling part, and the surface of the upper plastic facing the pressing block is provided with a matching part, and the matching part is connected with the anti-fooling part.

[0035] The foolproof part and the matching part are matched to prevent the compression block from being installed reversely, and when the compression block is assembled to the upper plastic, the foolproof effect can be achieved, and repeated adjustment of the compression block is avoided, thereby improving the assembly efficiency of the compression block and the upper plastic.

[0036] As an optional implementation, in the embodiment of the first aspect of the present application, the first pole column hole comprises a first sub-pole column hole and a second sub-pole column hole arranged at intervals.

[0037] The pole column structure comprises a first pole column and a second pole column, the first pole column is arranged in the first sub-pole column hole, the second pole column is arranged in the second sub-pole column hole, and the first pole column and the second pole column are both connected with the pole column connecting part.

[0038] In this way, the energy storage device in the present application can be a cylindrical battery with a double-pole column structure, compared with a cylindrical battery with a single-pole column structure, the torsional resistance of the pole column structure is improved, thereby facilitating the improvement of the electrical conductivity reliability of the pole column structure.

[0039] In a second aspect, the utility model discloses an energy storage system, the energy storage system has the energy storage device of the first aspect as described above. The energy storage system with the energy storage device of the first aspect, the current collector plate can also be folded to the side of the end cover through once bending to be fixedly connected with the pole column, the problem of difficult centering of the current collector plate into the shell is solved, thereby facilitating the assembly efficiency.

[0040] Compared with the prior art, the present application has the following advantages:

[0041] The energy storage device and the energy storage system provided by the embodiments of the present application are characterized in that the current collector plate and the end cover assembly are arranged separately, the pole column connecting part of the current collector plate is first welded with the pole lug of the bare battery cell, the pole column connecting part of the current collector plate is folded to the side of the end cover assembly through once bending of the bending part of the current collector plate, and the pole column connecting part of the current collector plate is penetrated and welded with the pole column structure of the end cover assembly. In the above assembly process, after the pole lug connecting part of the current collector plate is welded with the pole lug of the bare battery cell, the bare battery cell can be pressed by the equipment to facilitate the welding of the pole column structure, and the bending part of the current collector plate is bent once, so that the pole column connecting part of the current collector plate can be folded to the side of the end cover assembly to facilitate the penetration welding of the pole column connecting part and the pole column structure, thereby reducing the number of bending and improving the bending accuracy, thereby solving the problem of difficult centering of the current collector plate into the shell, and further improving the assembly efficiency of the energy storage device.

[0042] In addition, since the bending part of the current collector plate is only bent once, the current collector plate is no longer in a Z-shaped structure, the length of the current collector plate is shortened, the occupied space of the current collector plate is reduced, and the internal space of the energy storage device is saved. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

[0044] Figure 1 is a first structural schematic diagram of the energy storage system disclosed by the embodiments of the present application;

[0045] Figure 2 is a second structural schematic diagram of the energy storage system disclosed by the embodiments of the present application;

[0046] Figure 3 is a structural schematic diagram of the energy storage device disclosed by the embodiments of the present application;

[0047] Figure 4 is an exploded structural schematic diagram of the energy storage device disclosed by the embodiments of the present application;

[0048] Figure 5 is a top view of the energy storage device disclosed by the embodiments of the present application;

[0049] Figure 6 is a sectional view of the energy storage device disclosed by the embodiments of the present application along the A-A direction in Figure 5 ;

[0050] Figure 7 is an exploded view of Figure 6 ;

[0051] Figure 8 is a structural schematic diagram of the end cover assembly and the current collecting disc disclosed by the embodiments of the present application;

[0052] Figure 9 is an exploded structural schematic diagram of Figure 8 ;

[0053] Figure 10 is a structural schematic diagram of the end cover assembly and the current collecting disc from another perspective disclosed by the embodiments of the present application;

[0054] Figure 11 is a sectional view of the end cover assembly and the current collecting disc disclosed by the embodiments of the present application along the B-B direction in Figure 10 ;

[0055] Figure 12 is an exploded view of Figure 11 ;

[0056] Figure 13 is a local enlarged view of M in Figure 11 ;

[0057] Figure 14 isFigure 13 a local enlarged view of the N in

[0058] Figure 15 is a structural schematic view of the upper plastic disclosed by the embodiment of the present application;

[0059] Figure 16 is a structural schematic view of the upper plastic from another perspective disclosed by the embodiment of the present application;

[0060] Figure 17 is a structural schematic view of the pressing block disclosed by the embodiment of the present application.

[0061] Main figure mark explanation

[0062] 1000 - energy storage system;

[0063] 100 - energy storage device; 11 - shell; 111 - inner cavity; 112 - opening; 12 - bare battery cell; 13 - end cover assembly; 131 - end cover plate; 1311 - first pole column hole; 1311a - first sub-pole column hole; 1311b - second sub-pole column hole; 1312 - first exhaust passage; 132 - pole column structure; 132a - first pole column; 132b - second pole column; 1321 - pole column body; 1322 - abutment; 1323 - punched end; 1324 - fourth exhaust passage; 133 - lower plastic; 1331 - second pole column hole; 1331a - first hole section; 1331b - second hole section; 1331c - first step surface; 1332 - protruding part; 1333 - accommodation space; 134 - upper plastic; 134a - first surface; 134b - second surface; 134c - chamfer structure; 1341 - third pole column hole; 1342 - second exhaust passage; 1343 - annular protrusion; 1343a - abutting surface; 1344 - notch; 1345 - fitting part; 1346 - accommodation groove; 135 - sealing ring; 136 - pressing block; 1361 - fourth pole column hole; 1361a - third hole section; 1361b - fourth hole section; 1361c - second step surface; 1362 - third exhaust passage; 1363 - foolproof part; 14 - current collector plate; 141 - tab connecting part; 142 - pole column connecting part; 143 - bending part;

[0064] 200 - electric energy conversion device; 300 - first user load; 400 - second user load;

[0065] 210 - high-voltage cable; 310 - first electric energy conversion device; 410 - second electric energy conversion device. DETAILED DESCRIPTION

[0066] In order to make the purposes, technical solutions and advantages of the present application clearer, the following will clearly and completely describe the exemplary embodiments of the present application with reference to the accompanying drawings. Obviously, the described exemplary embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. That is, the specific embodiments described herein are only used to explain the present application, and are not intended to limit the present application.

[0067] It should be noted that the brief description of the terms in the present application is only for the convenience of understanding the embodiments described next, and is not intended to limit the embodiments of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments of the present application, and are not intended to limit the present application.

[0068] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0069] The terms "first", "second", and the like can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, the first pole can be referred to as the second pole, and similarly, the second pole can be referred to as the first pole. Both the first pole and the second pole are poles, but they are not the same pole.

[0070] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0071] In the description of the present application, it should be noted that the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0072] In the description of the present application, it should be noted that the singular form "one", "a" and "said / this" can also include the plural form, unless the context clearly indicates otherwise. It should also be understood that the term "includes / contains" or "has" and the like specifies the presence of the stated features, integers, steps, operations, components, parts or combinations thereof, but does not exclude the possibility of the presence or addition of one or more other features, integers, steps, operations, components, parts or combinations thereof.

[0073] In addition, the term "and / or" used in the specification includes any and all combinations of the related listed items, for example, A and / or B can mean: A exists alone, A and B exist together, B exists alone, that is, the term "and / or" used in the specification includes any and all combinations of the related listed items.

[0074] Since the energy required by people has strong time and space, in order to reasonably use energy and improve the utilization rate of energy, it is necessary to store one form of energy into the same or another form of energy through a medium or device, and release it in a specific energy form based on future application needs. It is well known that the main way to generate green electricity at present is to develop green energy such as photovoltaic and wind power to replace fossil energy.

[0075] At present, the generation of green electricity generally depends on photovoltaic, wind power, water potential, etc., while wind energy and solar energy have the problems of strong intermittency and large fluctuation, which will cause unstable power grid, insufficient electricity at peak load, too much electricity at low load, and unstable voltage will also cause damage to electricity, therefore, due to insufficient electricity demand or insufficient grid acceptance capacity, it may cause "abandoning wind and light" problem, in order to solve these problems, it is necessary to rely on energy storage, that is, to store electricity in other forms of energy through physical or chemical means, and release the electricity when needed. In short, energy storage is similar to a large "power bank", which stores electricity when photovoltaic and wind energy are sufficient, and releases the electricity when needed.

[0076] Taking electrochemical energy storage as an example, the energy storage device provided in the embodiments of the present application is internally provided with a group of energy storage batteries, mainly using chemical elements in the batteries as energy storage medium. The charging and discharging process is accompanied by chemical reaction or change of the energy storage medium. In simple terms, the wind energy and solar energy generated electric energy is stored in the chemical battery. When the use of external electric energy reaches the peak, the stored electric quantity is released for use, or transferred to the place where the electric quantity is in short supply for use.

[0077] At present, the energy storage application scenarios are relatively wide, including power generation side energy storage, power grid side energy storage, renewable energy grid-connected energy storage and user side energy storage, and the corresponding types of energy storage devices include:

[0078] ① Large energy storage containers applied in the power grid side energy storage scenario, which can be used as high-quality active and reactive power regulation power supply in the power grid, realize load matching of electric energy in time and space, enhance renewable energy consumption capacity, and are of great significance in power grid system backup, relieving peak load power supply pressure and peak regulation.

[0079] ② Medium and small energy storage cabinets applied in the industrial and commercial energy storage scenario of the user side (banks, shopping malls, etc.) and small household energy storage boxes applied in the household energy storage scenario of the user side, the main operation mode of which is "peak clipping and valley filling". Because there is a large price difference in electricity charges at peak and valley positions according to electricity demand, after the user has energy storage equipment, in order to reduce the cost, the energy storage cabinet / box is usually charged during the low electricity price period; the electricity in the energy storage equipment is discharged for use during the high electricity price period, so as to achieve the purpose of saving electricity charges. In addition, in remote areas and areas where natural disasters such as earthquakes and hurricanes are prone to occur, the existence of household energy storage devices is equivalent to that the user provides a standby power supply for himself and the power grid, which eliminates the inconvenience caused by frequent power outages due to disasters or other reasons.

[0080] Please refer to Figure 1 , Figure 1 The energy storage system provided in an embodiment of the present application is taken as a structural schematic diagram of a household energy storage system, and the energy storage device provided in the present application Figure 1 The embodiments of the present application take the household energy storage scenario in the user side energy storage as an example for description, and the energy storage device provided in the embodiments of the present application is not limited to the household energy storage scenario.

[0081] As Figure 1As shown, the energy storage system 1000 provided in this embodiment includes an energy storage device 100, a power conversion device 200 (photovoltaic panel), a first user load 300 (streetlight), and a second user load 400 (e.g., household appliances such as air conditioners). The energy storage device 100 is a small energy storage box that can be wall-mounted to an outdoor wall. Specifically, the photovoltaic panel can convert solar energy into electrical energy during periods of low electricity prices. The energy storage device 100 stores this electrical energy and supplies it to streetlights and household appliances during peak electricity prices, or provides power during power outages / power interruptions.

[0082] Please see Figure 2 , Figure 2 This is an exemplary structural diagram of an energy storage system provided in another embodiment of this application, and this application Figure 2 The embodiments are illustrated using a shared energy storage scenario on the generation / distribution side as an example. The energy storage device 100 of this application is not limited to its generation / distribution side energy storage scenario.

[0083] like Figure 2 As shown, the energy storage system 1000 provided in this application embodiment may include an energy storage device 100, a high-voltage cable 210, a first power conversion device 310, and a second power conversion device 410. During power generation, the first power conversion device 310 and the second power conversion device 410 convert other forms of energy into electrical energy, connect to the high-voltage cable 210, and supply the power to the distribution network. When the power load is low and the first power conversion device 310 and the second power conversion device 410 generate excess power, the excess power is stored in the energy storage device 100, reducing wind and solar curtailment rates and improving the absorption of new energy power generation. When the power load is high, the power grid issues an instruction to transmit the power stored in the energy storage device 100 in conjunction with the high-voltage cable 210 in a grid-connected mode to supply the power to the power user, providing various services such as peak shaving, frequency regulation, and backup for power grid operation, fully leveraging the peak shaving function of the power grid, promoting peak shaving and valley filling, and alleviating the power supply pressure on the power grid.

[0084] Optionally, the first and second electric energy conversion devices 310 and 410 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy, and mechanical energy into electric energy. In the present application, the number of energy storage devices 100 can be multiple, and the multiple energy storage devices 100 are connected in series or in parallel with each other, and the multiple energy storage devices 100 are supported and electrically connected by an isolation plate (not shown). In the present embodiment, "multiple" means two or more. The energy storage device 100 can also be provided with an energy storage box outside for accommodating the energy storage device 100. Optionally, the energy storage device 100 can include, but is not limited to, a single battery cell, a battery module, a battery pack, a battery system, etc. The actual application form of the energy storage device 100 provided in the present embodiment can be, but is not limited to, the listed products, and can also be other application forms, and the present embodiment does not strictly limit the application form of the energy storage device 100. The present embodiment only takes the energy storage device 100 as an example of a battery cell for illustration. When the energy storage device 100 is a battery cell, the energy storage device 100 can be at least one of a cylindrical battery, a square battery, etc. In order to more conveniently describe the energy storage device 100 provided in the present embodiment, as an example but not limitation, the energy storage device 100 will be taken as a cylindrical battery in the following to describe the technical solutions of the present application in detail.

[0085] Please refer to Figures 3 to 7 The energy storage device 100 provided in the present embodiment includes a shell 11, a bare battery cell 12, and an end cover assembly 13. The shell 11 has an inner cavity 111 and an opening 112 communicating with the inner cavity 111. The bare battery cell 12 is built in the inner cavity 111. The end cover assembly 13 includes an end cover plate 131 and a pole structure 132. The end cover plate 131 is sealingly arranged at the opening 112 to seal the bare battery cell 12 in the shell 11. The end cover plate 131 is provided with a first pole hole 1311 penetrating through the thickness direction thereof. The pole structure 132 is arranged in the first pole hole 1311 and electrically connected with the bare battery cell 12, so that the bare battery cell 12 is electrically connected with an external power source or an external device to be charged through the pole structure 132.

[0086] In some embodiments, the energy storage device 100 further includes a current collecting disc 14 located between the end cover assembly 13 and the bare battery cell 12. The current collecting disc 14 and the end cover assembly 13 are separately arranged. The current collecting disc 14 includes a tab connecting portion 141, a pole connecting portion 142, and a bending portion 143 connected between the tab connecting portion 141 and the pole connecting portion 142. The tab connecting portion 141 is connected with the tab of the bare battery cell 12. The bending portion 143 is bent once to make the pole connecting portion 142 arranged on the side of the end cover assembly 13. The pole connecting portion 142 is connected with the pole structure 132.

[0087] The application sets the current collector plate 14 separately from the end cover assembly 13, and connects the pole connecting part 142 of the current collector plate 14 to the pole lug of the bare battery cell 12 by welding, and then bends the pole connecting part 142 of the current collector plate 14 to the side of the end cover assembly 13 by one-time bending of the bending part 143 of the current collector plate 14, and then penetrates the pole connecting part 142 of the current collector plate 14 and the pole structure 132 of the end cover assembly 13.

[0088] In the above assembly process, after the pole lug connecting part 141 of the current collector plate 14 is welded to the pole lug of the bare battery cell 12, the bare battery cell 12 can be pressed by the equipment to facilitate the welding of the pole structure 132, and the bending part 143 of the current collector plate 14 is bent once, so that the pole connecting part 142 of the current collector plate 14 can be folded to the side of the end cover assembly 13 to facilitate the penetration welding of the pole connecting part 142 and the pole structure 132, thereby reducing the number of bending and improving the bending accuracy, thereby solving the difficulty of centering the current collector plate 14 into the shell, and further improving the assembly efficiency of the energy storage device 100.

[0089] In addition, since the bending part 143 of the current collector plate 14 is only bent once, the current collector plate 14 is no longer in a Z-shaped structure, the length of the current collector plate 14 is shortened, and the occupied space of the current collector plate 14 is reduced, thereby saving the internal space of the energy storage device 100.

[0090] In some embodiments, the first pole hole 1311 includes a first sub-pole hole 1311a and a second sub-pole hole 1311b arranged at intervals; the pole structure 132 includes a first pole 132a and a second pole 132b, the first pole 132a is arranged in the first sub-pole hole 1311a, the second pole 132b is arranged in the second sub-pole hole 1311b, and the first pole 132a and the second pole 132b are both connected to the pole connecting part 142.

[0091] In this way, the energy storage device 100 in the application can be a cylindrical battery with a double-pole structure, which improves the torsional resistance of the pole structure 132 compared to a cylindrical battery with a single-pole structure, thereby facilitating the improvement of the electrical conductivity reliability of the pole structure 132.

[0092] In the application, the material of the end cover plate 131 is generally metal, for example, the end cover plate 131 can be an aluminum sheet, a stainless steel plate, etc.

[0093] In order to realize the insulating connection of the pole structure 132 and the end cover plate 131, and realize the insulating connection of the current collector plate 14, the bare battery cell 12, etc. and the end cover plate 131, please refer to Figure 6 and Figure 7The end cover assembly 13 provided by the embodiments of the present application further comprises a lower plastic 133 arranged on the side of the end cover plate 131 facing the current collecting disc 14, and the lower plastic 133 is provided with a second pole column hole 1331 penetrating along the thickness direction of the lower plastic 133, and the second pole column hole 1331 is in communication with the first pole column hole 1311, wherein the pole column structure 132 is sequentially arranged in the second pole column hole 1331 and the first pole column hole 1311.

[0094] In some embodiments, the surface of the lower plastic 133 away from the end cover plate 131 is provided with a protruding portion 1332, and a receiving space 1333 is formed between the protruding portion 1332 and the lower plastic 133, wherein the pole lug connecting portion 141 and the bent portion 143 are located in the receiving space 1333, and the pole lug connecting portion 141 is abutted by the protruding portion 1332.

[0095] In this way, the protruding portion 1332 can press the pole lug connecting portion 141 of the current collecting disc 14 to press the bare battery cell 12, so as to avoid the bare battery cell 12 from shaking inside the shell 11, thereby ensuring the use safety of the energy storage device 100.

[0096] Optionally, as shown in Figure 8 and Figure 9 , the protruding portion 1332 can be multiple, for example, two, three, four, five or more, and the multiple protruding portions 1332 are arranged in a circumferential direction of the lower plastic 133, for example, the multiple protruding portions 1332 are arranged in a circumferential direction of the lower plastic 133.

[0097] The multiple protruding portions 1332 can better press the pole lug connecting portion 141 of the current collecting disc 14, and can effectively press the bare battery cell 12, so as to more effectively avoid the bare battery cell 12 from shaking inside the shell 11, thereby ensuring the use safety of the energy storage device 100.

[0098] In some embodiments, as shown in Figures 10 to 12 , the second pole column hole 1331 comprises a first hole section 1331a and a second hole section 1331b in communication with each other, the first hole section 1331a is connected with the first pole column hole 1311, and the hole diameter of the first hole section 1331a is smaller than the hole diameter of the second hole section 1331b to form a first step surface 1331c, the pole column structure 132 comprises a pole column body 1321 and a stop portion 1322 connected with each other, the pole column body 1321 is sequentially arranged in the first hole section 1331a and the first pole column hole 1311, the stop portion 1322 is arranged in the second hole section 1331b and abuts against the first step surface 1331c, and the stop portion 1322 is electrically connected with the pole lug connecting portion 141.

[0099] In this way, the abutting effect of the stop portion 1322 and the lower plastic 133 can prevent the pole structure 132 from being separated from the first pole hole 1311 and the second pole hole 1331, thereby improving the mounting stability of the pole structure 132.

[0100] To achieve the insulation connection between the pole structure 132 and the end cover plate 131, please refer to Figures 10 to 12 The end cover assembly 13 provided by the embodiment of the present application further includes an upper plastic 134, which is arranged on the side of the end cover plate 131 away from the current collecting disc 14, and the upper plastic 134 is provided with a third pole hole 1341 penetrating in the thickness direction thereof, the third pole hole 1341 being in communication with the first pole hole 1311, and the pole structure 132 is sequentially arranged in the first pole hole 1311 and the third pole hole 1341.

[0101] In some embodiments, the end cover assembly 13 further includes a sealing ring 135, which is sleeved on the outer periphery of the pole structure 132, and the sealing ring 135 is located between the outer peripheral surface of the pole structure 132 and the hole wall surface of the first pole hole 1311, and the sealing ring 135 abuts against the upper plastic 134, so that the sealing ring 135 can better block the gap between the outer peripheral surface of the pole structure 132 and the hole wall surface of the first pole hole 1311, thereby improving the sealing effect of the sealing ring 135.

[0102] Specifically, the sealing ring 135 is sleeved on the outer periphery of the pole body 1321, and the sealing ring 135 is located between the outer peripheral surface of the pole body 1321 and the hole wall surface of the first hole segment 1331a, the sealing ring 135 abuts against and is extruded by the end cover plate 131, and under the action of the extrusion force, the sealing ring 135 deforms towards the first pole hole 1311, so that the sealing ring 135 has a sealing portion located between the outer peripheral surface of the pole body 1321 and the hole wall surface of the first pole hole 1311, the sealing portion is abutted and deformed by the extrusion of the upper plastic 134, and can better block the gap between the outer peripheral surface of the pole body 1321 and the hole wall surface of the first pole hole 1311, thereby improving the sealing effect of the sealing ring 135.

[0103] Optionally, the sealing ring 135 can be, but is not limited to, a silica gel ring, a rubber ring, a plastic ring, etc.

[0104] In some embodiments, as shown in Figure 12 and Figure 13 , a first exhaust passage 1312 is arranged between the upper plastic 134 and the end cover plate 131, the first exhaust passage 1312 being in communication with the first pole hole 1311, and / or a second exhaust passage 1342 is arranged between the hole wall surface of the third pole hole 1341 and the outer peripheral surface of the pole structure 132, the second exhaust passage 1342 being in communication with the first pole hole 1311.

[0105] Thus, helium detection can be performed by the first exhaust passage 1312 and / or the second exhaust passage 1342 to detect the sealing performance of the sealing ring 135, that is, if helium is detected during helium detection, it indicates that the helium in the shell can be discharged to the first exhaust passage 1312 and / or the second exhaust passage 1342 through the gap between the hole wall surface of the first pole hole 1311 and the outer peripheral surface of the pole structure 132, and is detected, which indicates that the sealing ring 135 does not effectively seal the gap between the outer peripheral surface of the pole structure 132 and the hole wall surface of the first pole hole 1311; on the contrary, if helium is not detected during helium detection, it indicates that the helium in the shell cannot be discharged to the first exhaust passage 1312 and / or the second exhaust passage 1342 through the gap between the hole wall surface of the first pole hole 1311 and the outer peripheral surface of the pole structure 132, and cannot be detected, which indicates that the sealing ring 135 effectively seals the gap between the outer peripheral surface of the pole structure 132 and the hole wall surface of the first pole hole 1311, thereby detecting the sealing performance of the sealing ring 135.

[0106] An exemplary support structure (not shown) is provided between the end cover plate 131 and the upper plastic 134 to have a first gap between the end cover plate 131 and the upper plastic 134 by the support structure, the first gap is communicated with the first pole hole 1311, and the first gap constitutes the first exhaust passage 1312.

[0107] Another exemplary, the end cover plate 131 is in contact with the upper plastic 134, the surface of the end cover plate 131 towards the upper plastic 134 is provided with a first groove (not shown), and / or, the surface of the upper plastic 134 towards the end cover plate 131 is provided with a first groove (not shown), the first groove is communicated with the first pole hole 1311, and the first groove constitutes the first exhaust passage 1312.

[0108] Similarly, an exemplary, the hole wall surface of the third pole hole 1341 and the outer peripheral surface of the pole structure 132 are spaced apart to form a second gap, the second gap is communicated with the first pole hole 1311, and the second gap constitutes the second exhaust passage 1342.

[0109] Another exemplary, the hole wall surface of the third pole hole 1341 is provided with a second groove (not shown), and / or, the outer peripheral surface of the pole structure 132 is provided with a second groove (not shown), the second groove is communicated with the first pole hole 1311, and the second groove constitutes the second exhaust passage 1342.

[0110] In the present application, the upper plastic 134 has a first surface 134a and a second surface 134b opposite in the thickness direction of the upper plastic 134, wherein the first surface 134a can be arranged towards the end cover plate 131, and the second surface 134b is arranged away from the end cover plate 131.

[0111] The applicant finds that after the installation is completed, the sealing ring 135 will be extruded by the end cover plate 131, so that excessive stress is formed inside the sealing ring 135, which leads to a decrease in the service life of the sealing ring 135, and also causes the end cover plate 131 to be extruded and deformed by the sealing ring 135.

[0112] To this end, in some embodiments, as shown in Figures 12 to 14 The connection between the first surface 134a and the hole wall surface of the third pole post hole 1341 is provided with a chamfer structure 134c, and / or the connection between the second surface 134b and the hole wall surface of the third pole post hole 1341 is provided with a chamfer structure 134c.

[0113] In this way, a chamfer structure 134c is arranged at the contact position of the upper plastic 134 and the pole post structure 132. During the pressing and riveting process for fixing the pole post structure 132, stress is formed inside the sealing ring 135. The arrangement of the chamfer structure 134c allows the sealing ring 135 to release the excess amount to the gap between the chamfer structure 134c and the pole post structure 132 through stress when it is under pressure, thereby increasing the sealing effect of the sealing ring 135 on the pole post structure 132 and the upper plastic 134. At the same time, the stress of the sealing ring 135 can be partially released to protect the end cover plate 131 and the sealing ring 135.

[0114] In addition, when the hole wall surface of the third pole post hole 1341 and the outer peripheral surface of the pole post structure 132 are arranged to form the second exhaust passage 1342, during the pressing and riveting process for fixing the pole post structure 132, even if the pole post structure 132 expands, due to the arrangement of the chamfer structure 134c, the contact between the upper plastic 134 and the pole post structure 132 can be reduced, avoiding the blocking of the second exhaust passage 1342, which leads to the situation that the sealing effectiveness of the sealing ring 135 cannot be detected, so that the chamfer structure 134c can play a role in avoiding false sealing.

[0115] Optionally, the chamfer structure 134c can be an inverted bevel or an inverted round corner.

[0116] In order to increase the conductive area of the pole post structure 132 to improve the conductive reliability of the pole post structure 132, please refer to Figures 11 to 13The end cover assembly 13 provided by the embodiments of the present application further comprises a pressing block 136 arranged on the side of the upper plastic 134 away from the end cover plate 131, and the pressing block 136 is provided with a fourth pole column hole 1361 penetrating through the thickness direction of the pressing block 136, and the fourth pole column hole 1361 is in communication with the third pole column hole 1341, wherein the pole column structure 132 is sequentially arranged in the first pole column hole 1311, the third pole column hole 1341 and the fourth pole column hole 1361.

[0117] When the second exhaust passage 1342 is arranged between the hole wall surface of the third pole column hole 1341 and the outer circumferential surface of the pole column structure 132, the third exhaust passage 1362 is arranged between the pressing block 136 and the upper plastic 134, the third exhaust passage 1362 is in communication with the second exhaust passage 1342, and / or the fourth exhaust passage 1324 is arranged between the hole wall surface of the fourth pole column hole 1361 and the outer circumferential surface of the pole column structure 132, and the fourth exhaust passage 1324 is in communication with the second exhaust passage 1342.

[0118] In this way, when the sealing ring 135 cannot effectively seal the gap between the outer circumferential surface of the pole column structure 132 and the hole wall surface of the first pole column hole 1311, the channel for helium leakage is increased, and the helium can be smoothly leaked out, so as to improve the accuracy of helium detection, so that whether the sealing ring 135 is sealed well can be accurately detected, and the sealing effect of the sealing ring 135 can be ensured.

[0119] In some embodiments, the pole column body 1321 of the pole column structure 132 is formed with a stamping end 1323 at the end away from the abutting portion 1322, the fourth pole column hole 1361 comprises a third hole section 1361a and a fourth hole section 1361b in communication with each other, the third hole section 1361a is in communication with the third pole column hole 1341 and is used for arranging the pole column body 1321, the hole diameter of the fourth hole section 1361b is larger than that of the third hole section 1361a, so as to form a second step surface 1361c, and the stamping end 1323 of the pole column body 1321 after riveting is arranged in the fourth hole section 1361b and abuts against the second step surface 1361c.

[0120] That is, during riveting, the material of the stamping end 1323 of the pole column body 1321 is extruded outward by the riveting force of the rivet needle, so that the stamping end 1323 and the second step surface 1361c are in abutment, and the pole column body 1321 is fixedly connected with the pressing block 136. Therefore, the mounting stability of the pole column structure 132 can be improved.

[0121] In some embodiments, as Figure 14 and Figure 15As shown, the surface (i.e., the first surface 134a) of the upper plastic 134 facing the end cover plate 131 is provided with an annular protrusion 1343, which is arranged along the periphery of the third pole post hole 1341, and the annular protrusion 1343 is located in the first pole post hole 1311 and abuts against the sealing ring 135, wherein the pole post structure 132 is sequentially arranged in the first pole post hole 1311, the annular protrusion 1343 and the third pole post hole 1341.

[0122] In this way, the annular protrusion 1343 and the first pole post hole 1311 cooperate to provide initial positioning for the assembly of the upper plastic 134 and the end cover plate 131, thereby facilitating the assembly efficiency of the upper plastic 134 and the end cover plate 131.

[0123] In some embodiments, the annular protrusion 1343 has an abutting surface 1343a abutting against the sealing ring 135, and a chamfer structure 134c is arranged at the junction between the abutting surface 1343a and the hole wall surface of the third pole post hole 1341.

[0124] In this way, on the basis of the positioning effect of the annular protrusion 1343 and the first pole post hole 1311, the chamfer structure 134c is arranged at the contact position of the annular protrusion 1343 and the pole post structure 132. During the pressing process of the riveting mode for fixing the pole post structure 132, stress is formed inside the sealing ring 135. The arrangement of the chamfer structure 134c allows the sealing ring 135 to release the excess amount to the gap between the chamfer structure 134c and the pole post structure 132 through stress when the sealing ring 135 is pressed, thereby increasing the sealing effect of the sealing ring 135 on the pole post structure 132 and the upper plastic 134. At the same time, the stress of the sealing ring 135 can be partially released to protect the end cover plate 131 and the sealing ring 135.

[0125] In addition, when the hole wall surface of the third pole post hole 1341 and the outer peripheral surface of the pole post structure 132 are arranged to form the second exhaust passage 1342, during the pressing process of the riveting mode for fixing the pole post structure 132, even if the pole post structure 132 expands, due to the arrangement of the chamfer structure 134c, the contact between the annular protrusion 1343 and the pole post structure 132 can be reduced, avoiding the blocking of the second exhaust passage 1342, which leads to the situation that the sealing effectiveness of the sealing ring 135 cannot be detected, so that the chamfer structure 134c can avoid false sealing.

[0126] When the first exhaust passage is arranged between the upper plastic 134 and the end cover plate 131, the outer peripheral surface of the annular protrusion 1343 is recessed to form a notch 1344 away from the hole wall surface of the first pole post hole 1311, and the notch 1344 communicates with the first exhaust passage 1312.

[0127] In this way, by arranging the annular protrusion 1343 of the upper plastic 134 into the first pole post hole 1311 and arranging the notch 1344 on the outer circumferential surface of the annular protrusion 1343 corresponding to the first exhaust passage 1312, even in the process of riveting the pole post structure 132, when the pole post structure 132 is expanded to press the annular protrusion 1343, the outer circumferential surface of the annular protrusion 1343 abuts against the hole wall surface of the first pole post hole 1311, but due to the notch 1344, there is still a gap between the outer circumferential surface of the annular protrusion 1343 and the hole wall surface of the first pole post hole 1311 to communicate with the first exhaust passage 1312, so as to ensure that when the sealing ring 135 does not effectively seal between the hole wall surface of the first pole post hole 1311 and the outer circumferential surface of the pole post structure 132, helium can enter the first exhaust passage 1312 through the notch 1344 and be detected, thereby ensuring that the sealing performance of the sealing ring 135 can be effectively detected.

[0128] Optionally, the notch 1344 can be multiple, for example, two, three, four, five or more, and the multiple notches 1344 can be arranged at intervals along the circumference of the annular protrusion 1343, for example, the multiple notches 1344 are arranged at intervals along the circumference of the annular protrusion 1343. By arranging multiple notches 1344, the probability of the first pole post hole 1311 and the first exhaust passage 1312 being communicated can be increased when the pole post structure 132 is expanded to press the annular protrusion 1343.

[0129] In some embodiments, as shown in Figure 16 and Figure 17 The pressing block 136 is provided with a fool-proof part 1363 facing the surface of the upper plastic 134, and the upper plastic 134 is provided with a matching part 1345 facing the pressing block 136. The matching part 1345 is matched with the fool-proof part 1363 to prevent the pressing block 136 from being installed reversely. When the pressing block 136 is assembled to the upper plastic 134, the fool-proof part 1363 can prevent the pressing block 136 from being installed reversely, thereby improving the assembly efficiency of the pressing block 136 and the upper plastic 134.

[0130] When the fool-proof part 1363 is a fool-proof groove, the matching part 1345 is a fool-proof protrusion matched with the fool-proof groove; when the fool-proof part 1363 is a fool-proof protrusion, the matching part 1345 is a fool-proof groove matched with the fool-proof protrusion, and the fool-proof protrusion is inserted into the fool-proof groove to prevent the pressing block 136 from being installed reversely when the pressing block 136 is assembled to the upper plastic 134.

[0131] In some embodiments, the upper plastic 134 is provided with a receiving groove 1346 facing the pressing block 136, and the pressing block 136 is arranged in the receiving groove 1346, wherein the matching part 1345 is arranged on the groove bottom surface of the receiving groove 1346.

[0132] By setting the pressing block 136 in the accommodating groove 1346 of the upper plastic 134, the accommodating groove 1346 can roughly enclose the installation position of the pressing block 136 on the upper plastic 134, and the installation of the pressing block 136 can be positioned to some extent, so as to facilitate the installation of the pressing block 136, thereby improving the assembly efficiency of the pressing block 136 and the upper plastic 134.

[0133] In summary, in the energy storage device 100 provided in the present application, the end cover assembly 13 and the current collecting disc 14 are arranged in a split structure. After the installation of the pole structure 132, the lower plastic 133, the sealing ring 135, the end cover plate 131, the upper plastic 134, and the pressing block 136 to form the end cover assembly 13, the tab connecting portion 141 of the current collecting disc 14 is welded with the tab of the bare battery cell 12, and then the shell is entered. The bare battery cell 12 is pressed by the equipment to facilitate the welding of the pole structure 132, and the bending portion 143 of the current collecting disc 14 is bent once. The pole connecting portion 142 of the current collecting disc 14 can be bent to one side of the end cover assembly 13. Then, the pole connecting portion 142 of the current collecting disc 14 is penetrated and welded with the pole structure 132. In this way, the number of bending is reduced, the bending accuracy is improved, the difficulty of centering of the current collecting disc 14 into the shell is solved, and the assembly efficiency of the energy storage device 100 is improved.

[0134] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present application.

[0135] In addition, the above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the content of the present application should not be understood as a limitation, and the scope of protection of the present application should be subject to the appended claims.

Claims

1. An energy storage device, characterized by, The energy storage device comprises: a housing having an inner cavity and an opening in communication with the inner cavity; a bare cell built in the inner cavity; an end cover assembly comprising an end cover plate and a pole structure, the end cover plate is sealingly arranged at the opening, and the end cover plate is provided with a first pole hole penetrating through in the thickness direction thereof, and the pole structure is arranged in the first pole hole; and a current collector plate located between the end cover assembly and the bare cell, and the current collector plate and the end cover assembly are arranged separately, the current collector plate comprises a tab connecting portion, a pole connecting portion and a bending portion connected between the tab connecting portion and the pole connecting portion, the tab connecting portion is connected with the tab of the bare cell, the bending portion is bent once to make the pole connecting portion fold to one side of the end cover assembly, and the pole connecting portion is connected with the pole structure.

2. The energy storage device of claim 1, wherein, The end cover assembly further comprises a lower plastic, the lower plastic is arranged on one side of the end cover plate facing the current collector plate, and the lower plastic is provided with a second pole hole penetrating through in the thickness direction thereof, and the second pole hole is in communication with the first pole hole, wherein the pole structure is arranged in the second pole hole and the first pole hole in sequence; a surface of the lower plastic away from the end cover plate is provided with a protruding portion, a receiving space is formed between the protruding portion and the lower plastic, the pole connecting portion and the bending portion are located in the receiving space, and the tab connecting portion is abutted by the protruding portion.

3. The energy storage device of claim 1, wherein, The end cover assembly further comprises: an upper plastic arranged on one side of the end cover plate away from the current collector plate, and the upper plastic is provided with a third pole hole penetrating through in the thickness direction thereof, and the third pole hole is in communication with the first pole hole, wherein the pole structure is arranged in the first pole hole and the third pole hole in sequence, a first exhaust passage is arranged between the upper plastic and the end cover plate, the first exhaust passage is connected with the first pole hole, and / or a second exhaust passage is arranged between the hole wall surface of the third pole hole and the outer peripheral surface of the pole structure, and the second exhaust passage is in communication with the first pole hole; and a sealing ring sleeved on the outer periphery of the pole structure, and located between the outer peripheral surface of the pole structure and the hole wall surface of the first pole hole, and the sealing ring is abutted by the upper plastic.

4. The energy storage device of claim 3, wherein, The upper plastic has a first surface and a second surface opposite in the thickness direction thereof, a chamfer structure is arranged at the connection between the first surface and the hole wall surface of the third pole hole, and / or a chamfer structure is arranged at the connection between the second surface and the hole wall surface of the third pole hole.

5. The energy storage device of claim 3, wherein, When the first exhaust passage is arranged between the upper plastic and the end cover plate; a surface of the upper plastic facing the end cover plate is provided with an annular protrusion, the annular protrusion is arranged around the periphery of the third pole hole, the annular protrusion is located in the first pole hole and abutted by the sealing ring, and the pole structure is arranged in the first pole hole, the annular protrusion and the third pole hole in sequence; An outer circumferential surface of the annular protrusion is concavely formed with a notch in a direction away from a hole wall surface of the first pole post hole, and the notch is communicated with the first exhaust passage.

6. The energy storage device of claim 5, wherein, The annular protrusion has an abutting surface abutting against the sealing ring, and a connecting portion of the abutting surface and a hole wall surface of the third pole post hole is provided with a chamfer structure.

7. The energy storage device of claim 3, wherein, When the second exhaust passage is provided between the hole wall surface of the third pole post hole and the outer circumferential surface of the pole post structure; The end cover assembly further comprises a pressing block, the pressing block is arranged on a side of the upper plastic away from the end cover plate, and the pressing block is provided with a fourth pole post hole penetrating through in a thickness direction thereof, the fourth pole post hole is communicated with the third pole post hole, wherein the pole post structure is sequentially arranged in the first pole post hole, the third pole post hole and the fourth pole post hole. A third exhaust passage is provided between the pressing block and the upper plastic, the third exhaust passage is communicated with the second exhaust passage, and / or a fourth exhaust passage is provided between a hole wall surface of the fourth pole post hole and the outer circumferential surface of the pole post structure, the fourth exhaust passage is communicated with the second exhaust passage.

8. The energy storage device of claim 7, wherein, A foolproof part is arranged on a surface of the pressing block facing the upper plastic, and a matching part is arranged on a surface of the upper plastic facing the pressing block, the matching part is connected with the foolproof part.

9. The energy storage device of any one of claims 1-8, wherein, The first pole post hole comprises a first sub-pole post hole and a second sub-pole post hole arranged at intervals; The pole post structure comprises a first pole post and a second pole post, the first pole post is arranged in the first sub-pole post hole, the second pole post is arranged in the second sub-pole post hole, and the first pole post and the second pole post are both connected with the pole post connecting portion.

10. An energy storage system characterized by, The energy storage system has the energy storage device as claimed in any one of claims 1-9.

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