Energy storage device and energy storage system

Abstract

The utility model provides an energy storage device and an energy storage system, and relates to the technical field of energy storage. The energy storage device comprises a shell, a roll core, a cover plate and a collector plate, the shell comprises a main body and a mounting structure, the main body is provided with a first cavity, one end, in the first direction, of the main body is connected to the mounting structure, the mounting structure is provided with a second cavity, and a first opening of the second cavity is communicated with the first cavity; the mounting structure comprises a first side wall, a second side wall and a top wall, the first side wall is connected to the second side wall through the top wall, and the second side wall is closer to the center of the main body relative to the first side wall; the main body comprises a third side wall and a bottom wall, one end of the third side wall in the first direction is connected to the first side wall, and the other end is connected to the bottom wall; the roll core is arranged in the first cavity, and a gap is formed between the roll core and the third side wall of the main body; the cover plate covers the second opening of the second cavity; the flow collecting disc is positioned between the roll core and the cover plate; and an isolation cavity is formed among the second side wall of the mounting structure, the cover plate and the collector plate.

Description

TECHNICAL FIELD

[0001] The utility model relates to energy storage technology field in general, specifically, relate to a kind of energy storage device and energy storage system. BACKGROUND

[0002] The existing cylindrical battery includes a top cover, a current collector, an aluminum shell and a roll core. During assembly, the top cover is first welded with the aluminum shell to form a single-side opening structure. After the current collector is welded with the roll core, the current collector and the roll core are placed as a whole from the opening into the aluminum shell, and the protrusion in the middle of the current collector passes through the center hole of the top cover. Finally, the top cover and the current collector are welded and fixed at the matching position. A gap is provided between the roll core and the inner wall of the shell to facilitate the entry of the roll core into the aluminum shell.

[0003] However, during the assembly of the shell and the cover plate, metal wires and other impurities are easily scratched. If the metal wire falls through the gap to the negative terminal and abuts against the inner wall of the shell, the shell is electrically connected to the negative terminal through the metal wire, resulting in a short circuit problem, which affects the use reliability of the cylindrical battery. SUMMARY

[0004] The energy storage device and energy storage system provided by the utility model can reduce the risk of short circuit and improve the use reliability.

[0005] According to a first aspect of the utility model, an energy storage device is provided, comprising:

[0006] A shell includes a main body and a mounting structure. The main body is provided with a first cavity. The main body is connected to the mounting structure at one end along a first direction. The mounting structure is provided with a second cavity. The second cavity has a first opening and a second opening along the first direction. The first opening is in communication with the first cavity. The mounting structure includes a first side wall, a second side wall and a top wall. The first side wall and the second side wall are oppositely arranged in a second direction. The first side wall is connected to the second side wall through the top wall. The second side wall is closer to the center of the main body than the first side wall. The main body includes a third side wall and a bottom wall. One end of the third side wall is connected to the first side wall along the first direction, and the other end is connected to the bottom wall.

[0007] A roll core is arranged in the first cavity. A gap is formed between the roll core and the third side wall of the main body.

[0008] A cover plate is sealed to the second opening of the second cavity.

[0009] A current collector is located between the roll core and the cover plate.

[0010] The second side wall of the mounting structure, the cover plate and the current collector form an isolation cavity.

[0011] The first direction and the second direction are perpendicular.

[0012] In some embodiments, the second side wall is a stepped structure.

[0013] In some embodiments, the second side wall comprises at least one step, and the cover plate is connected to the at least one step.

[0014] In some embodiments, the cover plate and the current collector plate are arranged on two sides of the step along the first direction.

[0015] Alternatively, the cover plate and the current collector plate are connected to two steps.

[0016] In some embodiments, the step has a first step surface and a second step surface connected to each other, the first step surface is arranged to extend along the first direction, the second step surface is arranged to extend along the second direction, the cover plate is at least partially fitted with the first step surface around the side surface along the first direction, and the cover plate is at least partially fitted with the second step surface along the bottom surface of the side of the winding core.

[0017] In some embodiments, along the first direction, the current collector plate is provided with a protruding portion away from the winding core, and the protruding portion is connected to the second side wall.

[0018] The isolation cavity is arranged between the second side wall, the protruding portion, the cover plate, and the current collector plate.

[0019] In some embodiments, further comprising:

[0020] An explosion-proof valve is arranged on the cover plate, the current collector plate is provided with a center through hole and an exhaust through hole, and the center through hole and the explosion-proof valve are arranged correspondingly.

[0021] The number of the protruding portions is multiple, an exhaust groove is arranged between two adjacent protruding portions, one end of the exhaust groove along the second direction is communicated with the gap, and the other end of the exhaust groove is communicated with the center through hole.

[0022] In some embodiments, a separation cavity is formed between the first side wall, the second side wall, the top wall, and the current collector plate.

[0023] The current collector plate and the third side wall are arranged to be spaced apart.

[0024] In some embodiments, the first side wall, the second side wall, the top wall, the third side wall, and the bottom wall are integrally formed.

[0025] And / or, along the second direction, the difference between the maximum width of the first side wall and the maximum width of the isolation cavity is greater than the wall thickness of the third side wall.

[0026] According to a second aspect of the present application, the present application further provides a kind of energy storage system, comprising the energy storage device described above.

[0027] One embodiment of the present application has the following advantages or beneficial effects:

[0028] The energy storage device provided in the embodiment utilizes the internal space between the second side wall, the cover plate and the current collecting disc of the mounting structure as an isolation cavity, which provides a relatively closed space for impurities generated when the shell and the cover plate are connected, so that the impurities are contained and limited in the isolation cavity, reducing the risk of short circuit caused by impurities falling through the gap to the negative electrode terminal, and improving the use reliability of the energy storage device. In addition, one end of the top wall connected to the second side wall along the second direction and towards the center of the main body, and one end of the top wall connected to the first side wall along the second direction and away from the center of the main body, so that the second side wall of the mounting structure extends along the second direction and towards the center direction of the main body relative to the third side wall, so that the second side wall and the gap are staggered with each other, further reducing the risk of impurities falling into the gap.

[0029] The present application further provides an energy storage system, comprising the energy storage device described above, which is convenient for improving the working stability of the energy storage system based on the electrical safety of the energy storage device during use. BRIEF DESCRIPTION OF DRAWINGS

[0030] Wherein:

[0031] Figure 1 Fig. 1 shows a structural schematic diagram of an energy storage system according to an embodiment of the present application;

[0032] Figure 2 Fig. 2 shows a structural schematic diagram of an energy storage device according to an embodiment of the present application;

[0033] Figure 3 Fig. 3 shows a sectional view of the energy storage device according to an embodiment of the present application;

[0034] Figure 4 Fig. 4 shows a structural schematic diagram of the shell in the energy storage device according to an embodiment of the present application; Figure 1

[0035] Figure 5 Fig. 5 shows a structural schematic diagram of the shell in the energy storage device according to an embodiment of the present application; Figure 2

[0036] Figure 6 Fig. 6 shows a sectional view of the positive electrode terminal in the energy storage device according to an embodiment of the present application; ​​

[0037] Figure 7 Fig. 1 shows a structure diagram of an installation structure in an energy storage device according to an embodiment of the present application. Figure 1 ;

[0038] Figure 8 Fig. 1 shows a structure diagram of an installation structure in an energy storage device according to an embodiment of the present application. Figure 2 ;

[0039] Figure 9 Fig. 1 shows a structure diagram of an installation structure in an energy storage device according to an embodiment of the present application.

[0040] Figure 10 Fig. 1 shows a structure diagram of an installation structure in an energy storage device according to an embodiment of the present application.

[0041] Figure 11 Fig. 1 shows a structure diagram of an installation structure in an energy storage device according to an embodiment of the present application.

[0042] Among them, the sign explanation is as follows:

[0043] 100, energy storage device; 200, electric energy conversion device; 300, user load;

[0044] 1, shell; 2, cover plate; 3, winding core; 4, current collector plate; 5, explosion-proof valve; 6, top patch;

[0045] 10, gap; 11, main body; 110, first cavity; 111, third side wall; 112, bottom wall;

[0046] 12, installation structure; 120, second cavity; 121, second side wall; 1211, first step surface; 1212, second step surface; 122, first side wall; 123, top wall;

[0047] 30, heat dissipation channel;

[0048] 20, isolation cavity; 21, liquid injection hole;

[0049] 40, separation cavity; 41, protruding part; 42, center through hole; 43, exhaust through hole; 44, exhaust groove. DETAILED DESCRIPTION

[0050] The technical solutions in the example embodiments of the present application will be described clearly and completely in combination with the drawings in the example embodiments of the present application. The described example embodiments in this paper are only for the purpose of illustration, and are not used to limit the protection scope of the present application, so it should be understood that various modifications and changes can be made to the example embodiments without departing from the protection scope of the present application.

[0051] In the description of the utility model, unless otherwise expressly specified and limited, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance; the term "a plurality of" means two or more than two; the term "and / or" includes any combination and all combinations of one or more associated listed items. In particular, referring to "the" object or "one" object is also intended to represent one of the possible multiple such objects.

[0052] Unless otherwise specified or explained, the terms "connection", "fixing" and the like should be broadly understood, for example, "connection" can be fixed connection, or detachable connection, or integral connection, or electrical connection, or signal connection; "connection" can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0053] Further, in the description of the utility model, it should be understood that the "upper", "lower", "inner", "outer" and the like described in the example embodiments of the utility model are described from the angle shown in the drawings, and should not be understood as limiting the example embodiments of the utility model. It should also be understood that in the context, when referring to one element or feature connected to another element (one or more) "on", "below", or "inside", "outside", it can not only be directly connected to another element (one or more) "on", "below", or "inside", "outside", but also indirectly connected to another element (one or more) "on", "below", or "inside", "outside" through an intermediate element.

[0054] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations, however, can be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example implementations to those skilled in the art. Identical reference numerals in the drawings represent the same or similar structures, so detailed description thereof will be omitted.

[0055] Since the energy required by people has strong time and space, in order to reasonably use energy and improve the utilization rate, it is necessary to store one energy form into the same energy form or convert into another energy form through a medium or equipment, and then release it in a specific energy form based on future application.

[0056] At present, green energy mainly includes light energy, wind energy, etc., and light energy and wind energy have the problems of strong intermittency and large fluctuation, which can cause the voltage instability of green power grid. Therefore, the problems of "abandoning wind and light" can be caused due to insufficient power demand or insufficient power grid receiving capacity.

[0057] To solve the problems of insufficient power demand or insufficient power grid receiving capacity, it is necessary to rely on energy storage devices. That is, through the energy storage device, the electrical energy is converted into other forms of energy by physical or chemical means for storage, and the energy stored in the energy storage device is converted into electrical energy for release when needed. In simple terms, the energy storage device is similar to a large "power bank". When light energy and wind energy are sufficient, the electrical energy is stored, and the stored electrical energy is released when needed.

[0058] At present, the application scenarios of energy storage are relatively wide, including energy storage on the power generation side, energy storage on the power grid side, renewable energy grid-connected energy storage, and energy storage on the user side. The corresponding types of energy storage devices include:

[0059] The large energy storage container applied in the energy storage scenario on the power grid side can be used as a high-quality active and reactive power regulation power source in the power grid, realizes the load matching of electrical energy in time and space, enhances the renewable energy consumption capacity, and has great significance in terms of power grid system backup, relieving peak load power supply pressure, and peak regulation and frequency regulation.

[0060] The small and medium-sized energy storage cabinet applied in the industrial and commercial energy storage scenario on the user side and the small household energy storage box applied in the household energy storage scenario on the user side mainly operate in the mode of "peak clipping and valley filling". Because there is a large price difference in electricity charges at peak and valley positions according to power demand, after the user has an energy storage device, in order to reduce costs, the energy storage device is usually charged at the low valley period of electricity price; the electricity in the energy storage device is discharged for use at the high peak period of electricity price, so as to achieve the purpose of saving electricity charges. In addition, in remote areas and areas with high incidence of natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices is equivalent to providing backup power for the user and the power grid, which eliminates the inconvenience caused by frequent power outages due to disasters or other reasons.

[0061] The energy storage system provided by the embodiments of the present application includes an energy storage device to realize the storage or supply of electrical energy through the energy storage device.

[0062] Taking the household energy storage scenario in the user-side energy storage as an example, Figure 1This diagram illustrates an energy storage system according to an embodiment of this application. The system includes an energy storage device 100, a power conversion device 200, and a user load 300. The power conversion device 200 is electrically connected to the energy storage device 100, and the energy storage device 100 is electrically connected to the user load 300. The energy storage device 100 is a small energy storage box that can be wall-mounted to an outdoor wall. Specifically, the power conversion device 200 converts solar energy into electrical energy, which is then stored in the energy storage device 100. This stored energy is then supplied to the user load 300 during peak electricity price periods or during power outages / power interruptions.

[0063] The energy storage device 100 can be a battery pack, battery box, or battery system composed of individual battery cells. The individual battery cells can be secondary batteries such as lithium-ion batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, and magnesium-ion batteries, and can be cylindrical, flat, cuboid, etc., without limitation in the embodiments of this application. Furthermore, the battery cells can utilize the chemical reaction or change of the energy storage medium to achieve the charging and discharging process. Simply put, the electrical energy generated by solar or wind power is stored in the battery cells through the chemical reaction or change of the energy storage medium. When the external electrical energy usage reaches its peak, the electrical energy stored in the battery cells is released for use or transferred for later use through the chemical reaction or change of the energy storage medium.

[0064] The energy storage system provided in this application includes the aforementioned energy storage device 100. During the use of the energy storage system, the power safety of the energy storage device 100 facilitates the improvement of the working stability of the energy storage system.

[0065] This embodiment also provides an energy storage device 100, such as Figures 2-4 As shown, the energy storage device 100 includes a housing 1, a cover plate 2, a core 3, and a collector plate 4. The housing 1 can be a cylindrical structure, a cuboid structure, or other regular or irregular structure. The housing 1 is made of aluminum or aluminum alloy, meaning it is lightweight. The housing 1 has a hollow structure with an internal cavity. The core 3 is disposed within this cavity, and the housing 1 provides space for the core 3, protecting it. The energy storage device 100 has a positive and a negative terminal. The cover plate 2 and the collector plate 4 are located at the positive terminal. The collector plate 4 is disposed within the housing 1 and between the core 3 and the cover plate 2, and is connected to at least one of the housing 1 and the cover plate 2.

[0066] The shell 1 is a two-end opening structure, that is, the shell 1 has a top opening and a bottom opening. In the assembly process, the current collector plate 4 and the winding core 3 are first welded to form an integrated structure, the integrated structure enters the shell 1 from the bottom opening of the shell 1, and the integrated structure enters the shell from the negative electrode end to the positive electrode end. After the current collector plate 4 is welded to the shell 1 or the cover plate 2, the cover plate 2 is arranged on the top opening of the shell 1 and is welded to complete the assembly process.

[0067] Exemplarily, the current collector plate 4 can be directly connected to the shell 1, or the current collector plate 4 is connected to the cover plate 2. In another embodiment, the current collector plate 4 is provided with a protruding structure on the side facing the cover plate 2, the cover plate 2 is provided with a center hole, and then the protruding structure of the current collector plate 4 is arranged in the center hole of the cover plate 2 to realize the positioning between the current collector plate 4 and the cover plate 2. Finally, the protruding structure and the inner wall of the center hole are welded and fixed at the position where they match each other.

[0068] Specifically, the shell 1 includes a main body 11. In this embodiment, the main body 11 is a cylindrical structure. The axial direction of the main body 11 is a first direction, which is denoted by D1. The radial direction of the main body 11 is a second direction, which is denoted by D2. The first direction and the second direction are perpendicular to each other. The main body 11 includes a third side wall 111 and a bottom wall 112. The bottom wall 112 is arranged at the bottom of the third side wall 111 along the first direction. The bottom opening is arranged on the bottom wall 112.

[0069] The size of the bottom opening is less than or equal to the inner diameter of the third side wall 111. When the size of the bottom opening is less than the inner diameter of the third side wall 111, the bottom opening is a through hole arranged on the bottom wall 112. When the size of the bottom opening is equal to the inner diameter of the third side wall 111, the bottom opening is a bottom end surface of the third side wall 111 along the first direction.

[0070] Exemplarily, as shown in Figures 5-6 The main body 11 is provided with a first cavity 110, and the winding core 3 is arranged in the first cavity 110. A gap 10 is formed between the winding core 3 and the third side wall 111 of the main body 11. The gap 10 can be used to conveniently guide the winding core 3 into the shell 1 during assembly. However, impurities are easily generated during the assembly process of the shell 1 and the cover plate 2. If the material of the impurities is metal, when the impurities fall to the negative electrode end through the gap 10 and abut against the inner wall of the shell 1, a short circuit problem occurs, which affects the use reliability of the energy storage device 100.

[0071] To solve this problem, as shown in Figure 4 and Figure 6As shown, the housing 1 also includes a mounting structure 12. One end of the main body 11 along the first direction is connected to the mounting structure 12. The mounting structure 12 is provided with a second cavity 120. The second cavity 120 has a first opening and a second opening along the first direction. The first opening is connected to the first cavity 110. The cover plate 2 covers the second opening of the second cavity 120. At this time, the second opening is the top opening of the main body 11.

[0072] Specifically, such as Figure 4 and Figures 6-7 As shown, the mounting structure 12 includes a first sidewall 122, a second sidewall 121, and a top wall 123. Along a first direction, the first sidewall 122 is connected to the bottom wall 112 via a third sidewall 111. The first sidewall 122 and the second sidewall 121 are arranged opposite each other in a second direction. The first sidewall 122 is connected to the second sidewall 121 via the top wall 123. The second sidewall 121 is closer to the center of the main body 11 than the first sidewall 122. The center of the main body 11 is specifically the centerline of the main body 11 or the central axis of the main body 11.

[0073] It is understandable that the first sidewall 122, the second sidewall 121, the top wall 123, the third sidewall 111, and the bottom wall 112 are integrally formed structures, which saves the steps of individual parts processing and assembly, and saves production costs.

[0074] An isolation cavity 20 is formed between the second sidewall 121 of the mounting structure 12, the cover plate 2, and the collector plate 4. Exemplarily, the internal space enclosed by the bottom surface of the cover plate 2 along the first direction, the top surface of the collector plate 4 along the first direction, and the second sidewall 121 constitutes the isolation cavity 20. The isolation cavity 20 is used to accommodate and isolate impurities generated when the housing 1 and the cover plate 2 are connected. Specifically, the impurities are metal wires generated when the cover plate 2 and the housing 1 are closed due to wire drawing.

[0075] The energy storage device 100 provided in this embodiment utilizes the internal space between the second sidewall 121 of the mounting structure 12, the cover plate 2, and the collector plate 4 as an isolation cavity 20. The isolation cavity 20 provides a relatively enclosed space for impurities generated when the housing 1 and the cover plate 2 are connected, so that the impurities are contained and confined within the isolation cavity 20, reducing the risk of impurities falling through the gap 10 to the negative terminal and causing a short circuit, thereby improving the reliability of the energy storage device 100. In addition, the top wall 123 is connected to the second sidewall 121 at one end along the second direction and toward the center of the main body 11, and the top wall 123 is connected to the first sidewall 122 at the other end along the second direction and away from the center of the main body 11. Thus, the second sidewall 121 of the mounting structure 12 extends relative to the third sidewall 111 along the second direction and toward the center of the main body 11, so that the second sidewall 121 and the gap 10 are offset from each other, further reducing the risk of impurities falling into the gap 10.

[0076] Specifically, the projections of the isolation cavity 20 onto the reference plane and the gap 10 onto the reference plane do not coincide; and / or, the projections of the second sidewall 121 onto the reference plane and the gap 10 onto the reference plane do not coincide. The reference plane is perpendicular to the first direction, and the reference plane can specifically be the top surface of the core 3 along the first direction. In this manner, the isolation cavity 20 and the gap 10 are staggered, further reducing the risk of impurities in the isolation cavity 20 entering the gap 10.

[0077] In one embodiment, such as Figures 7-8 As shown, the mounting structure 12 can be a hollow structure or a solid structure. Along the second direction, the difference between the maximum width of the first sidewall 122 and the maximum width of the isolation cavity 20 is greater than the wall thickness of the third sidewall 111. This arrangement causes the second sidewall 121 of the mounting structure 12 to contract towards the center of the housing 1 relative to the third sidewall 111. The second sidewall 121 is away from the gap 10. When the cover plate 2 is placed over the second opening of the second cavity 120, the connection position of the cover plate 2 will also be away from the gap 10, preventing impurities from falling into the gap 10.

[0078] In one embodiment, the second sidewall 121 is a stepped structure, and the cover plate 2 is connected to the stepped structure. With this configuration, the second sidewall 121 provides an installation position for the cover plate 2. When the cover plate 2 and the second sidewall 121 are welded, any impurities generated can be contained within the isolation cavity 20 to achieve the purpose of isolating impurities and preventing impurities from falling through the gap 10 to the negative terminal and causing a short circuit.

[0079] Specifically, the second sidewall 121 includes at least one step, and the cover plate 2 is connected to at least one step.

[0080] For example, when there is one step, the cover plate 2 is connected to the step. Specifically, the cross-section of one step is an L-shaped structure, and along the first direction, one side of the step is connected to the cover plate 2, and the other end is connected to the manifold 4.

[0081] For example, when there are multiple steps, the multiple steps are arranged along the first direction, so that the multiple steps are staggered in height along the first direction. The multiple steps increase the overall height space of the isolation cavity 20 along the first direction, thereby increasing the content space of the isolation cavity 20. In addition, the second side wall 121 of the mounting structure 12 adopts a folded edge design. Multiple steps can be formed by bending multiple times along the first and second directions, reducing the difficulty and cost of production and processing.

[0082] Specifically, the plurality of steps include a first step and a second step, the first step and the second step are arranged up and down along the first direction, and the second step is located inside the first step, that is, the first step and the second step are sleeved and connected with each other, and the outer diameter size of the first step is larger than the outer diameter size of the second step. In this way, the cover plate 2 can be connected to any one or more steps, so that cover plates 2 of different sizes can select steps corresponding to their sizes, meet the installation needs of cover plates 2 of different models and types, and have strong versatility.

[0083] In one embodiment, the cover plate 2 and the current collector plate 4 are located on both sides of the second side wall 121, avoiding the interference between the cover plate 2 and the current collector plate 4 and the second side wall 121 during welding, simplifying the installation and assembly process, and saving production costs.

[0084] In one embodiment, as shown in Figure 8 the cover plate 2 and the current collector plate 4 are connected to two steps. For example, if the outer diameter size of the cover plate 2 is relatively large, the cover plate 2 is connected to the first step located above along the first direction, and the current collector plate 4 is connected to the second step located below along the second direction. In this way, the welding positions of the cover plate 2 and the current collector plate 4 are dispersed in two different steps, the welding space is relatively large, the assembly difficulty is reduced, and the risk of welding breakdown is reduced.

[0085] In other embodiments, the cover plate 2 and the current collector plate 4 are arranged on both sides of the same step along the first direction. For example, if the outer diameter size of the cover plate 2 is relatively small, the cover plate 2 is connected to the upper surface of the second step along the first direction, and the current collector plate 4 is connected to the lower surface of the second step along the first direction. That is, the cover plate 2 and the current collector plate 4 are arranged on both sides of the same step along the first direction, avoiding interference during welding and simplifying the installation and assembly process. It can be understood that only the local area of the step can be locally strengthened before welding, reducing the local strengthening area and saving production costs.

[0086] In one embodiment, as shown in Figure 8 the first step has a first step surface 1211 and a second step surface 1212 connected with each other, the first step surface 1211 is arranged to extend along the first direction, the second step surface 1212 is arranged to extend along the second direction, the cover plate 2 is at least partially attached to the first step surface 1211 around the peripheral surface along the first direction, and the bottom surface of the cover plate 2 along the first direction and towards one side of the winding core 3 is at least partially attached to the second step surface 1212.

[0087] During assembly, the collector plate 4 with the core 3 and the housing 1 are first subjected to penetration welding, and then the seam welding between the housing 1 and the cover plate 2 is performed. Specifically, the second step surface 1212 provides a certain supporting force for the cover plate 2. The bottom surface of the cover plate 2 and the second step surface 1212 are welded together, and the peripheral side surface of the cover plate 2 is welded to the first step surface 1211, so that there are at least two connection points between the cover plate 2 and the second side wall 121, thereby increasing the connection stability of the cover plate 2.

[0088] Meanwhile, along the first direction, the connection point between the first step and the cover plate 2 is lower than the top surface of the top wall 123. With this arrangement, the welding point between the first step and the cover plate 2 will be hidden inside the housing 1 and will not be exposed outside the housing 1, thus ensuring the smoothness of the surface of the housing 1.

[0089] It is understood that the first step is essentially a groove on the second sidewall 121 that is recessed relative to the top wall 123 and extends away from the cover plate 2. The groove is an annular groove, and its shape matches the shape of the cover plate 2. The bottom of the groove is the second step surface 1212, which supports the cover plate 2 and provides it with a certain degree of support. The sidewall of the groove is the first step surface 1211, which contacts the circumferential sidewall of the cover plate 2, thus limiting the position of the cover plate 2. Furthermore, since the groove is recessed relative to the top wall 123, the bottom and / or wall of the groove are welded to the cover plate 2, and this connection is hidden inside the housing 1, resulting in a good aesthetic appearance.

[0090] Furthermore, existing side laser welding methods can affect the cladding, and because the positive end is at the bottom when assembling the module, the weld protrusion causes the bottom diameter of the housing to increase, while the module size is fixed, which affects the assembly effect. However, in the energy storage device 100 provided in this embodiment, the welding position between the cover plate 2 and the housing 1 is concentrated at the top, which will not cause the bottom diameter of the housing 1 to be too large, thus ensuring the reliability of the assembly.

[0091] like Figure 8 As shown, along the first direction, a protrusion 41 is provided on the side of the collector plate 4 away from the core 3, and the protrusion 41 is connected to the second side wall 121.

[0092] When the protrusion 41 and the second sidewall 121 are welded, the top surface of the protrusion 41 is higher than the top surface of the collector plate 4, which increases the distance between the connection position between the collector plate 4 and the second sidewall 121 and the core 3, thus avoiding the situation where the core 3 is damaged after the through weld is burned through. In addition, the protrusion 41 is far away from the position where the second sidewall 121 and the cover plate 2 are closed and the wire is pulled, so the protrusion 41 can better isolate impurities such as metal wires.

[0093] Exemplarily, the protrusion 41 can be a protrusion provided on the top surface of the current collector plate 4. The protrusion can be a solid structure or a hollow structure. Alternatively, the current collector plate 4 can be formed by stamping to form the protrusion 41, and the current collector plate 4 and the protrusion 41 can be integrally formed to reduce assembly difficulty and cost.

[0094] Exemplarily, the protrusion 41 can be at least one of a block structure, a strip structure or a circular arc structure. The shape of the protrusion 41 is not limited in the embodiment and can be adjusted according to actual production conditions.

[0095] The isolation cavity 20 is arranged between the second side wall 121, the protrusion 41, the cover plate 2 and the current collector plate 4. Since the protrusion 41 protrudes from the current collector plate 4, the height space of the isolation cavity 20 in the first direction is further increased, and impurities generated during welding of the protrusion 41 and the second side wall 121 can also be directly accommodated in the isolation cavity 20, reducing the risk of short circuit caused by impurities entering the negative electrode end through the gap 10.

[0096] In one embodiment, as shown in Figure 9 The first side wall 122, the top wall 123, the second side wall 121 and the current collector plate 4 form a separation cavity 40, and the current collector plate 4 is arranged apart from the third side wall 111, i.e. the separation cavity 40 and the gap 10 are communicated. The space between the cover plate 2 and the current collector plate 4 is separated by the second side wall 121 to form the isolation cavity 20 and the separation cavity 40. In this way, the second side wall 121 is an isolation structure between the isolation cavity 20 and the separation cavity 40, so that the impurities in the isolation cavity 20 cannot enter the separation cavity 40, and even less can enter the gap 10 through the separation cavity 40.

[0097] In one embodiment, as shown in Figures 9-10 The cover plate 2 can be a circular plate structure, and the cover plate 2 is provided with a liquid injection hole 21 for injecting electrolyte.

[0098] As shown in Figures 9-11 The energy storage device 100 further includes an explosion-proof valve 5 arranged on the cover plate 2. The current collector plate 4 is provided with a central through hole 42 and an exhaust through hole 43, and the central through hole 42 and the explosion-proof valve 5 are arranged correspondingly. A heat dissipation channel 30 is arranged at the center of the winding core 3 along the first direction. The heat generated by thermal runaway of the winding core 3 is dissipated through the heat dissipation channel 30, and then discharged to the explosion-proof valve 5 through the central through hole 42 and the exhaust through hole 43. The heat is discharged to the outside atmosphere through the explosion-proof valve 5 after impacting the explosion-proof valve 5, so as to achieve the purpose of heat dissipation of the winding core 3.

[0099] The number of the exhaust through holes 43 is multiple, and the multiple exhaust through holes 43 are arranged around the central through hole 42 to further improve the heat dissipation effect.

[0100] In one embodiment, the energy storage device 100 further comprises a top patch 6, which is attached to the cover plate 2 and at least partially covers the explosion-proof valve 5, so as to isolate and protect the explosion-proof valve 5 from damage caused by external force impact. It can be understood that the explosion-proof valve 5 itself can also have an explosion-proof valve piece.

[0101] It can be understood that when the winding core 3 is in thermal runaway, the heat generated by the circumferential side of the winding core 3 will pass through the gap 10. If the protruding part 41 is a circular ring structure, although the isolation cavity 20 is a completely closed structure, this part of the heat cannot be discharged through the explosion-proof valve 5, and the expansion of the heat will cause the shell 1 to deform.

[0102] Therefore, the current collecting disc 4 is provided with an exhaust groove 44, which is communicated with the gap 10 at one end and communicated with the center through hole 42 at the other end in the radial direction of the shell 1. In this way, the heat generated by the circumferential side of the winding core 3 will enter the partition cavity 40 through the gap 10, and the heat in the partition cavity 40 will be guided to the center through hole 42 through the exhaust groove 44. The exhaust groove 44 functions as a conveying channel, and finally discharges through the explosion-proof valve 5, improves the heat dissipation effect, and reduces the risk of deformation of the shell 1.

[0103] Specifically, the number of protruding parts 41 is multiple, and the multiple protruding parts 41 are arranged on the current collecting disc 4 in the circumferential direction of the shell 1. Among them, the exhaust groove 44 is arranged between the adjacent two protruding parts 41.

[0104] Exemplarily, the protruding part 41 is not a complete continuous structure, the number of protruding parts 41 is three, and the three protruding parts 41 form an interrupted circular ring structure. The adjacent two protruding parts 41 are interrupted gaps, which provide a setting position for the exhaust groove 44, so that the heat in the gap 10 flows to the explosion-proof valve 5 through the exhaust groove 44. With this arrangement, the connection of the current collecting disc 4 and the second side wall 121 and the double effect of the exhaust channel can be considered at the same time.

[0105] It should be noted that the embodiments of the present application can be understood that only one example of the principle of the present application is shown in the drawings and described in the specification. Those skilled in the art should clearly understand that the principle of the present application is not limited to any detail or any component of the device shown in the drawings or described in the specification.

[0106] It is to be understood that the present application is not limited to the particular details of construction and arrangement described herein and illustrated in the drawings. The present application is capable of other embodiments and of being practiced or carried out in a variety of ways. Variations and modifications of the described embodiments are considered to be within the scope of the present application. It is to be understood that the present application extends to all alternative combinations of two or more of the individual features mentioned or evident from the description and / or drawings. All these different combinations constitute various alternative aspects of the present application. The embodiments described are illustrative of the best modes known to the inventors of practicing the present application and of the ways in which the present application can be carried out. The present application is not limited to these embodiments.

[0107] Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The present application is intended to cover any and all variations of the application following in general the principles of the application using the knowledge of equivalents, and it is intended to be limited only by the claims. The specification and examples given are intended as illustrative only and not in a limiting sense. The true scope of the present application is indicated by the appended claims.

[0108] It is to be understood that the application is not limited to the particular details described above and illustrated in the drawings. Various modifications and changes can be made to the application without departing from its scope. The scope of the application is limited only by the claims that follow.

Claims

1. An energy storage device, characterized in that, include: A housing includes a main body and a mounting structure. The main body has a first cavity, and one end of the main body along a first direction is connected to the mounting structure. The mounting structure has a second cavity, and the second cavity has a first opening and a second opening along the first direction, with the first opening communicating with the first cavity. The mounting structure includes a first sidewall, a second sidewall, and a top wall. The first sidewall and the second sidewall are disposed opposite each other in a second direction. The first sidewall is connected to the second sidewall through the top wall, and the second sidewall is closer to the center of the main body than the first sidewall. The main body includes a third sidewall and a bottom wall, with one end of the third sidewall connected to the first sidewall along the first direction and the other end connected to the bottom wall. A core is disposed in the first cavity, and a gap is formed between the core and the third sidewall of the main body; A cover plate, which seals the second opening of the second cavity; A collector plate is located between the winding core and the cover plate; An isolation cavity is formed between the second sidewall of the mounting structure, the cover plate, and the collector plate; Wherein, the first direction and the second direction are perpendicular.

2. The energy storage device according to claim 1, characterized in that, The second sidewall has a stepped structure.

3. The energy storage device according to claim 2, characterized in that, The second sidewall includes at least one step, and the cover plate is connected to at least one of the steps.

4. The energy storage device according to claim 3, characterized in that, The cover plate and the collecting plate are disposed on both sides of the same step along the first direction; Alternatively, the cover plate and the collector plate are connected to the two steps respectively.

5. The energy storage device according to claim 3, characterized in that, The step has a first step surface and a second step surface that are connected to each other. The first step surface extends along the first direction, and the second step surface extends along the second direction. The cover plate has at least a portion of its circumferential side surface around the first direction that is in contact with the first step surface, and at least a portion of the bottom surface of the cover plate along the first direction and facing the core side is in contact with the second step surface.

6. The energy storage device according to claim 1, characterized in that, Along the first direction, the collector plate has a protrusion on the side away from the winding core, and the protrusion is connected to the second sidewall; The isolation cavity is disposed between the second side wall, the protrusion, the cover plate and the collector plate.

7. The energy storage device according to claim 6, characterized in that, Also includes: An explosion-proof valve is provided on the cover plate, and the collecting plate is provided with a central through hole and an exhaust through hole, with the central through hole and the explosion-proof valve being provided correspondingly; The number of protrusions is multiple, and an exhaust groove is provided between two adjacent protrusions. One end of the exhaust groove along the second direction is connected to the gap, and the other end is connected to the central through hole.

8. The energy storage device according to any one of claims 1-7, characterized in that, A partition cavity is formed between the first sidewall, the second sidewall, the top wall, and the collector plate; The collector plate and the third sidewall are spaced apart.

9. The energy storage device according to any one of claims 1-7, characterized in that, The first sidewall, the second sidewall, the top wall, the third sidewall, and the bottom wall are integrally formed. And / or, along the second direction, the difference between the maximum width of the first sidewall and the maximum width of the isolation cavity is greater than the wall thickness of the third sidewall.

10. An energy storage system, characterized in that, Includes the energy storage device according to any one of claims 1-9.

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