Battery, electric device, energy storage system, and power station

Abstract

The present application relates to a battery, an electric device, an energy storage system, and a power station. During the structural design of the battery, the maximum size of conductive particles in an adhesive layer in a direction perpendicular to the thickness direction of the adhesive layer is controlled to be less than or equal to the adhesive thickness of the adhesive layer, and the projection size of the conductive particles in the thickness direction is reduced. Additionally, the minimum value of the distance between the conductive particles and the surface of the adhesive layer facing a battery cell is controlled to be greater than zero, so that each conductive particle does not exceed the surface of the adhesive layer facing the battery cell. By means of such design, the size and position distribution of the conductive particles in the adhesive layer are controlled, charge accumulation of the conductive particles in the adhesive layer is reduced, the probability of occurrence of partial discharge is effectively reduced, and the reliability of the battery is improved.

Description

Batteries, electrical devices, energy storage systems and power stations Related applications

[0001] This application claims priority to Chinese patent application filed on August 24, 2024, application number 2024111758562, entitled "Battery, Electrical Device, Energy Storage System and Power Station", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to batteries, their preparation methods, electrical devices, and energy storage systems. Background Technology

[0003] With the development of power systems, energy storage technology has become increasingly important, especially battery energy storage systems, which can effectively alleviate the growing energy crisis and reduce traditional carbon dioxide emissions. However, due to the limitations of traditional battery structure design, partial discharge problems are prone to occur; if operated for a long time, it can easily lead to insulation aging, insulation problems developing into insulation failure, and the energy storage system failing to operate reliably. Summary of the Invention

[0004] Therefore, it is necessary to provide a battery, an energy storage system for electrical devices, and a power station that can effectively reduce the probability of partial discharge and improve battery reliability.

[0005] In a first aspect, this application provides a battery, comprising: a gel layer having a plurality of conductive particles therein; and a battery cell disposed on a surface of the gel layer along its thickness direction; wherein the thickness of the gel layer is denoted as d1, the maximum distance between any two points on the outer contour line of each conductive particle on the cross section of the largest area perpendicular to the thickness direction is denoted as d2, and the minimum distance between the surface of each conductive particle facing the gel layer and the surface of the gel layer facing the battery cell is denoted as d3, wherein 0 < d2 < d1, and d3 > 0.

[0006] In the aforementioned battery design, the maximum size of the conductive particles in the adhesive layer along the direction perpendicular to the thickness of the adhesive layer is controlled to be smaller than the thickness of the adhesive layer, thus reducing the projected size of the conductive particles along the thickness direction. Simultaneously, the minimum distance between the conductive particles and the surface of the adhesive layer facing the battery cell is controlled to be greater than zero, ensuring that each conductive particle does not extend beyond the surface of the adhesive layer facing the battery cell. This design controls the size and positional distribution of the conductive particles in the adhesive layer, reducing charge accumulation in the particles, effectively reducing the probability of partial discharge, and improving battery reliability.

[0007] In some embodiments, at least some of the projections of the conductive particles along the thickness direction of the adhesive layer are spaced apart or adjacent to each other. This design controls the absence of other conductive particles in the projection regions of the conductive particles along the thickness direction of the adhesive layer, thereby reducing the charge accumulation capacity in the projection regions of the conductive particles along the thickness direction and further reducing the probability of partial discharge.

[0008] In some embodiments, 0 < d2 < 0.9 × d1. This design further reduces the size d2 of the conductive particles, weakens the influence of the conductive particles on charge accumulation, and reduces the probability of partial discharge.

[0009] In some embodiments, 0 < d2 ≤ d1 / 2, and d1 / 4 ≤ d3 < d1. When the size of the conductive particles is less than or equal to half the adhesive thickness, and their distribution position is greater than or equal to one-quarter of the adhesive thickness, the charge accumulation of the conductive particles in the electric field can be effectively reduced, thus lowering the probability of partial discharge.

[0010] In some embodiments, the battery further includes an insulating film that covers at least one side of the battery cell facing the adhesive layer, and the battery cell is bonded to the adhesive layer through the insulating film; the side of the insulating film facing away from the adhesive layer is fully bonded to the side of the battery cell facing the adhesive layer. This design ensures that one side of the insulating film is fully bonded to one side of the battery cell, resulting in a tight fit, reducing local bonding defects, and achieving more effective insulation protection.

[0011] In some embodiments, the battery further includes an insulating film that covers at least one side of the battery cell facing the adhesive layer. The battery cell is bonded to the adhesive layer via the insulating film. A protrusion is provided on the side of the insulating film bonded to the adhesive layer. The protrusion is configured to be formed by impurities between the insulating film and the battery cell protruding from the insulating film. The maximum height of the protrusion is denoted as h, and the thickness of the insulating film is denoted as d4, where d4 ≥ h. This design, in the case of impurities between the battery cell and the insulating film, controls the protrusion height to not exceed the thickness of the insulating film, which helps reduce the risk of partial discharge and improves battery reliability.

[0012] In some embodiments, the thickness d4 satisfies the condition: 0.05mm ≤ d4 ≤ 1mm. This design controls the thickness of the insulating film between 0.05mm and 1mm, effectively balancing the battery's insulation performance and energy density.

[0013] In some embodiments, the thickness d4 also satisfies the condition: 0.099mm ≤ d4 ≤ 0.5mm. This design further controls the thickness of the insulating film between 0.099mm and 0.5mm, making it easier to effectively balance the insulation performance and energy density of the battery.

[0014] In some embodiments, the adhesive layer further includes air bubbles, and the projections of the air bubbles along the thickness direction of the adhesive layer and the projections of the protrusions along the thickness direction of the adhesive layer at least partially overlap. The maximum distance between any two points on the outer contour line of the air bubble on its cross-section perpendicular to the thickness direction is denoted as d5, where 0 < d5 ≤ 0.3 × d1. This design ensures that, even with air bubbles in the adhesive layer and the overlapping projections of the protrusions and air bubbles in the thickness direction, the maximum distance d5 between the air bubbles does not exceed 0.3 times the thickness of the adhesive layer, reducing the range of partial discharge and improving battery reliability.

[0015] In some embodiments, the adhesive layer also contains bubbles. The projections of the bubbles along the thickness direction of the adhesive layer and the projections of the protrusions along the thickness direction of the adhesive layer are spaced apart or adjacent. The maximum distance between any two points on the outer contour line of a bubble on its cross-section perpendicular to the thickness direction is denoted as d5, where 0 < d5 < d1. Therefore, when bubbles are present in the adhesive layer, controlling the projections of the protrusions and bubbles to be staggered along the thickness direction, and ensuring that the bubble size d5 is smaller than the thickness of the adhesive layer, can reduce the risk of partial discharge caused by the combined effect of the bubbles and protrusions in the adhesive layer, thus improving battery reliability.

[0016] In some embodiments, the projections of bubbles along the thickness direction of the adhesive layer and the projections of each conductive particle along the thickness direction of the adhesive layer are spaced apart or adjacent. This design allows for reasonable control of the distribution of bubbles and conductive particles in the adhesive layer, further reducing the probability of partial discharge and improving battery reliability.

[0017] In some embodiments, the thickness d1 satisfies the condition: 0.5mm ≤ d1 ≤ 5mm. This design controls the thickness of the adhesive layer between 0.5mm and 5mm, effectively balancing the battery's insulation performance and energy density.

[0018] In some embodiments, the thickness d1 also satisfies the condition: 0.5mm ≤ d1 ≤ 3mm. This design further controls the thickness of the adhesive layer between 0.5mm and 3mm, making it easier to effectively balance the insulation performance and energy density of the battery.

[0019] In some embodiments, the battery further includes a base, on which the adhesive layer is disposed on the side facing away from the battery cell. This design, with the introduction of the base, facilitates stable fixation of the battery cell.

[0020] Secondly, this application provides an electrical device, which includes any of the batteries described above.

[0021] Thirdly, this application provides an energy storage system, which includes the battery described above. By employing the structural design of the battery described above, controlling the size and positional distribution of conductive particles in the adhesive layer, and / or the size and positional distribution of protrusions in the insulating film or bubbles in the adhesive layer, the charge accumulation of conductive particles in the adhesive layer can be reduced, and / or the range and distribution of the dielectric constant threshold region can be controlled, thereby effectively reducing the probability of partial discharge and improving battery reliability.

[0022] In some embodiments, the energy storage system is a high-voltage energy storage system with a rated voltage greater than or equal to 1 kV; in some examples, the rated voltage of the energy storage system is greater than or equal to 6 kV; in some examples, the rated voltage of the energy storage system is greater than or equal to 35 kV. This design, by introducing the above-mentioned batteries into the high-voltage energy storage system, can effectively reduce the probability of partial discharge, improve battery reliability, and extend the operating life of the energy storage system.

[0023] In some embodiments, the energy storage system includes several cascaded energy storage devices; each energy storage device includes a power module and several electrical cabinets. The input terminals of the power modules are cascaded to achieve cascading of the energy storage devices, and the output terminals of the power modules are connected to all electrical cabinets. Each electrical cabinet includes several batteries connected in series. This design, by introducing the above-mentioned batteries into the high-voltage cascaded energy storage system, can effectively reduce the probability of partial discharge in the high-voltage cascaded energy storage system, thus improving the reliability of the energy storage system operation.

[0024] Fourthly, this application provides a power plant that includes the energy storage system described above. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the disclosed drawings without creative effort.

[0026] Figure 1 is a schematic diagram of the structure of an energy storage system provided in some embodiments of this application.

[0027] Figure 2 is a schematic diagram of the structure of an energy storage device provided in some embodiments of this application.

[0028] Figure 3 is an exploded view of a battery provided in some embodiments of this application.

[0029] Figure 4 is an exploded structural diagram of a battery cell provided in some embodiments of this application.

[0030] Figure 5 is a schematic diagram of the internal structure of a battery provided in some embodiments of this application.

[0031] Figure 6 is a schematic diagram of the cross-section of the maximum area of ​​the conductive particles in the vertical thickness direction provided in some embodiments of this application.

[0032] Figure 7 is a schematic diagram of the distribution structure of two conductive particles provided in some embodiments of this application.

[0033] Figure 8 is a schematic diagram of the distribution structure of two conductive particles provided in some embodiments of this application.

[0034] Figure 9 is a schematic diagram of the internal structure of a battery provided in some embodiments of this application.

[0035] Figure 10 is a schematic diagram of the internal structure of a battery provided in some embodiments of this application.

[0036] Figure 11 is an enlarged schematic diagram of the structure at circle B in Figure 10.

[0037] Figure 12 is a schematic diagram of the internal structure of a battery provided in some embodiments of this application.

[0038] Figure 13 is a schematic diagram of the structure of an energy storage device provided in some embodiments of this application.

[0039] Figure 14 is a schematic diagram of the structure of a DC direct-connected energy storage system provided in some embodiments of this application.

[0040] Figure 15 is a schematic diagram of the structure of an AC direct-connected energy storage system provided in some embodiments of this application.

[0041] Figure 16 is a schematic diagram of the structure of an AC direct-connected cascaded energy storage system provided in some embodiments of this application.

[0042] 101. Monitoring backend; 102. System controller; 104. Battery management controller; 105. Submodule controller; 100. Battery; 10. Battery cell; 11. End cap; 12. Electrode terminal; 13. Electrode assembly; 14. Housing; 20. Insulating film; 21. Impurities; 22. Protrusion; 30. Adhesive layer; 31. Conductive particles; 32. Bubble; X, thickness direction; 40. Battery box; 41. Cover; 42. Base; 200. Energy storage device; 210. Power module; 220. Electrical cabinet; 221. Main control box; 230. Positive connection wire; 240. Negative connection wire; 300. Energy storage module; 310. Reactor; 400. Positive DC bus; 410. Negative DC bus; 500. AC bus. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0045] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0046] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0048] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0049] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0050] With the development of power systems, energy storage technology has become increasingly important, especially battery energy storage systems, which can effectively alleviate the growing energy crisis and reduce traditional carbon dioxide emissions. A battery energy storage system generally includes an energy storage device, a battery management system (BMS), a power conversion system (PCS), and an energy management system (EMS). The energy storage device, consisting of multiple batteries connected in series and parallel, is the core of the battery energy storage system.

[0051] Typically, a battery consists of individual battery cells and a battery casing that houses them. The battery cells are bonded to the base of the battery casing with adhesive layers, and a voltage difference usually exists between the battery cells and the casing. However, due to the structural design limitations of traditional batteries, their early insulation capacity is insufficient, leading to partial discharge between the battery cells and the casing. If this battery operates for a long time, it can easily cause insulation aging, insulation problems to develop, and eventually insulation failure, resulting in unreliable operation of the energy storage system, or even serious safety issues such as system shutdown, fire, and explosion.

[0052] Based on this, and addressing the problem of insulation failure easily caused by partial discharge in traditional energy storage systems, this application provides a battery in which the maximum size of conductive particles in the adhesive layer along the direction perpendicular to the thickness of the adhesive layer is controlled to be less than or equal to half the thickness of the adhesive layer, thereby reducing the projected size of the conductive particles along the thickness direction. Simultaneously, the minimum distance between the conductive particles and the surface of the adhesive layer facing the battery cell is controlled to be greater than one-quarter of the adhesive thickness, ensuring that each conductive particle maintains a reasonable distance from the battery cell in the thickness direction. This design controls the size and positional distribution of conductive particles in the adhesive layer, reduces charge accumulation in the adhesive layer, effectively reduces the probability of partial discharge, and improves battery reliability.

[0053] The batteries disclosed in this application can be used, but are not limited to, energy storage systems, and can also be used in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using battery cells and batteries disclosed in this application.

[0054] The batteries provided in this application embodiment have different structural forms depending on different application scenarios. For example, in an electrical device, they can be a battery pack or a battery module; in an energy storage system, they can be an electrical box. When the battery of this application is applied to the energy storage system shown in Figure 1, the energy storage system includes a monitoring backend 101, a system controller (Valve Base Controller, VBC) 102, multiple energy storage devices 200, a battery management controller (BMC) 104 and a sub-module controller (SMC) 105 corresponding to each energy storage device 200. The battery management controller 104 and the sub-module controller 105 are connected in a one-to-one communication manner. The monitoring backend 101 is connected in communication with the system controller 102 and each battery management controller 104. The system controller 102 is also connected in communication with each sub-module controller 105. The battery management controller 104 is used to obtain the status information of the corresponding energy storage device 200. The sub-module controller 105 is used to control the corresponding energy storage device 200. The monitoring backend 101 is used to perform status monitoring. The system controller 102 is used to obtain the communication status of each communication path in the energy storage system and perform corresponding processing actions according to the communication status.

[0055] In this embodiment of the application, the energy storage system includes multiple energy storage devices 200. Each energy storage device 200 may be composed of multiple electrical cabinets 220 connected in series and / or in parallel. Each electrical cabinet 220 may be composed of multiple electrical boxes connected in series and / or in parallel. Each electrical box may be composed of multiple battery cells 10 connected in series and / or in parallel, as shown in Figure 2.

[0056] The energy storage system also includes a battery management controller 104 corresponding to the energy storage device 200. The battery management controller 104 can collect the status information of the corresponding energy storage device 200 and is responsible for detecting the battery's status, performance, and health status. The aforementioned status information may include voltage, current, temperature, state of charge / discharge, state of charge (SOC), state of health (SOH), etc.

[0057] The energy storage system also includes a module controller 105 that is communicatively connected to the battery management controller 104. The battery management controller 104 can transmit the collected status information to the module controller 105, and the module controller 105 can also transmit control commands to the battery management controller 104, thereby controlling the corresponding energy storage device 200. For example, it can control the energy storage device 200 to enter or leave the energy storage system, and can also control the charging and discharging of the energy storage device 200.

[0058] Please refer to Figure 3, which is an exploded view of a battery 100 provided in some embodiments of this application. The battery 100 includes a battery case 40 and a battery cell 10, with the battery cell 10 housed within the battery case 40. The battery case 40 provides a space for the battery cell 10 and can adopt various structures. In some embodiments, the battery case 40 may include a cover 41 and a base 42, with the cover 41 and base 42 overlapping each other, jointly defining a space for accommodating the battery cell 10. The base 42 may be a hollow structure with one open end, and the cover 41 may be a plate-like structure, covering the open side of the base 42 so that the cover 41 and base 42 jointly define the space; alternatively, both the cover 41 and base 42 may be hollow structures with one open side, with the open side of the cover 41 overlapping the open side of the base 42. Of course, the battery case 40 formed by the cover 41 and base 42 can be of various shapes, such as a cylinder, a cuboid, etc.

[0059] In battery 100, there can be multiple battery cells 10, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 10 are connected in both series and parallel configurations. Multiple battery cells 10 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 10 is housed within battery box 40. Alternatively, battery 100 can also be composed of multiple battery cells 10 first connected in series, parallel, or in a mixed manner to form battery modules, and then these modules are connected in series, parallel, or in a mixed manner to form a whole, which is then housed within battery box 40. Battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 10.

[0060] Please refer to Figure 4, which is an exploded structural diagram of a battery cell 10 provided in some embodiments of this application. A battery cell 10 refers to the smallest unit that makes up a battery 100. As shown in Figure 4, the battery cell 10 includes an end cap 11, a housing 14, an electrode assembly 13, and other functional components.

[0061] End cap 11 refers to a component that covers the opening of housing 14 to isolate the internal environment of battery cell 10 from the external environment. The shape of end cap 11 can be adapted to the shape of housing 14 to fit it. End cap 11 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 11 is not easily deformed under pressure and impact, allowing battery cell 10 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 12 can be provided on end cap 11. Electrode terminals 12 can be used for electrical connection with electrode assembly 13 for outputting or inputting electrical energy to battery cell 10. In some embodiments, end cap 11 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 10 reaches a threshold. The material of end cap 11 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 11. The insulating element can be used to isolate the electrical connection components within the housing 14 from the end cap 11 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0062] The housing 14 is a component used to cooperate with the end cap 11 to form the internal environment of the battery cell 10, wherein the formed internal environment can be used to accommodate the electrode assembly 13, electrolyte, and other components. The housing 14 and the end cap 11 can be independent components. An opening can be provided on the housing 14, and the end cap 11 closes the opening to form the internal environment of the battery cell 10. Alternatively, the end cap 11 and the housing 14 can be integrated. In some embodiments, the end cap 11 and the housing 14 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 14, the end cap 11 closes the housing 14. The housing 14 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. In some embodiments, the shape of the housing 14 can be determined according to the specific shape and size of the electrode assembly 13. The material of the housing 14 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this.

[0063] Electrode assembly 13 is the component in the battery cell 10 where the electrochemical reaction occurs. The casing 14 may contain one or more electrode assemblies 13. The electrode assembly 13 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 13, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery 100, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals 12 to form a current loop.

[0064] According to some embodiments of this application, referring to FIG5, this application provides a battery 100, which includes an adhesive layer 30 and a battery cell 10. The adhesive layer 30 has a plurality of conductive particles 31, and the battery cell 10 is disposed on a surface of the adhesive layer 30 along its thickness direction X. The thickness of the adhesive layer 30 is denoted as d1. The maximum distance between any two points on the outer contour line of each conductive particle 31 on the cross-section of the largest area perpendicular to the thickness direction X is denoted as d2. The minimum distance between the surface of each conductive particle 31 facing the adhesive layer 30 and the surface of the adhesive layer 30 facing the battery cell 10 is denoted as d3. Where 0 < d2 < d1, and d3 > 0.

[0065] The adhesive layer 30 refers to the structure used to bond and fix the battery cell 10, and also to provide insulation for the battery cell 10 in the battery 100. The material of the adhesive layer 30 can be selected from various types, such as, but not limited to, AB glue, polyurethane rubber (PU), epoxy resin, silane coupling agent, etc.

[0066] Conductive particles 31 refer to conductive particles in the adhesive layer 30, such as particles with a conductivity greater than 10⁶ S / m. In some embodiments, the conductive particles may be aluminum metal particles. Because the conductive particles 31 have a strong charge accumulation capacity, the electric field distribution of the battery cell 10 on the adhesive layer 30 changes under the influence of the conductive particles 31. This causes electric field accumulation on the side of the conductive particles 31 facing the battery cell 10, making it easier for partial discharge to occur between the conductive particles 31 and the battery cell 10.

[0067] Therefore, in this embodiment, the maximum value d2 of the connection distance between conductive particles 31 is controlled to be less than or equal to the thickness of the adhesive layer 30. For example, the maximum value d2 can be, but is not limited to, 9×d1 / 10, d1 / 2, d1 / 3, d1 / 4, d1 / 5, d1 / 6, d1 / 7, d1 / 8, d1 / 9, d1 / 10, etc. The projection of conductive particles 31 along the thickness direction X is controlled within a certain range, which can reduce the relative area between conductive particles 31 and battery cell 10 in the thickness direction X of adhesive layer 30. At the same time, the minimum value of the distance between conductive particles 31 and the surface of adhesive layer 30 facing battery cell 10 is greater than zero. For example, the minimum distance d3 can be, but is not limited to, d1 / 2, d1 / 3, d1 / 4, d1 / 5, d1 / 6, d1 / 7, d1 / 8, d1 / 9, d1 / 10, etc., so that conductive particles 31 do not exceed the surface of adhesive layer 30. Therefore, when the size of the conductive particles 31 is less than or equal to the adhesive thickness and their distribution position does not exceed the surface of the adhesive layer, the charge accumulation of the conductive particles 31 in the electric field can be effectively reduced, thus reducing the probability of partial discharge.

[0068] The maximum line distance d2 of conductive particles 31 can be understood as follows: Several cross-sections of conductive particles 31 are obtained by cutting them with a plane perpendicular to the thickness direction X of the adhesive layer 30. The cross-section with the largest area is selected, and any two points are taken on the outer contour line of this cross-section. The distance between these two points is then obtained by connecting them. The maximum value among all these distances is taken as the maximum line distance d2 of conductive particles 31. For ease of understanding, taking Figure 6 as an example, the outer contour line of the largest area cross-section of conductive particles 31 is the contour line indicated by A in Figure 6, and the maximum line distance d2 is the maximum distance between any two points on contour line A in Figure 6.

[0069] Of course, if the conductive particle 31 is a sphere or a similar spherical particle, the maximum distance d2 of the connecting line is the diameter of the conductive particle 31.

[0070] It should also be noted that the minimum distance between the surface of each conductive particle 31 facing the adhesive layer 30 and the surface of the adhesive layer 30 facing the battery cell 10 can be understood as: starting from the part of the conductive particle 31 closest to the adhesive layer 30, draw a line segment along the thickness direction X from the adhesive layer 30 towards the battery cell 10, and the distance of this line segment is the minimum distance d3.

[0071] Furthermore, the thickness of adhesive layer 30 can be the average thickness of adhesive layer 30. When adhesive layer 30 has a uniform thickness, the thickness can be taken from any point on adhesive layer 30. When adhesive layer 30 has an unequal thickness, the thickness values ​​from multiple points on adhesive layer 30 can be averaged, and the calculated value can be used as the thickness of adhesive layer 30. There are various methods for measuring the thickness of adhesive layer 30, such as using instruments including, but not limited to, micrometers and X-ray thickness gauges.

[0072] It is easy to understand that after the battery cell 10 is bonded to the adhesive layer 30, the conductive particles 31 in the adhesive layer 30 will be opposite to the battery cell 10 along the thickness direction X. For example, the projection of the conductive particles 31 along the thickness direction X of the adhesive layer 30 will fall on the side where the battery cell 10 is bonded to the adhesive layer 30. At the same time, there can be multiple battery cells 10, and each battery cell 10 can be connected in series and / or connected in parallel in the battery 100.

[0073] Furthermore, the control of the size and positional distribution of conductive particles 31 in the adhesive layer 30 can be achieved in various ways. For example, before applying the adhesive, the adhesive can be thoroughly stirred to ensure that the size of the conductive particles 31 meets the above conditions; after stirring, the adhesive can also be filtered. After applying the adhesive, the adhesive layer 30 that meets the conditions can be screened using detection methods, such as visual inspection, camera photography, image recognition, or X-ray photography, to intercept adhesive layers 30 that do not meet the requirements. Of course, before bonding the battery cells 10, the battery cells 10 can be dusted, for example, by using a vacuum cleaner or hair dryer; or, lint-free paper or adhesive tape can be used to bond the surface of the battery cells 10 to reduce the number of conductive particles 31 on the surface of the battery cells 10, thereby reducing the number of conductive particles 31 mixed into the adhesive layer 30. It should be noted that the above-provided implementation methods are only examples of feasible methods and are not intended to limit the implementation methods of controlling the size and positional distribution of conductive particles 31.

[0074] This design controls the size and positional distribution of conductive particles 31 in the adhesive layer 30, reduces the charge accumulation of conductive particles 31 in the adhesive layer 30, effectively reduces the probability of partial discharge, and improves the reliability of the battery 100.

[0075] According to some embodiments of this application, referring to Figures 7 and 8, in the projections of each conductive particle 31 along the thickness direction X of the adhesive layer 30, at least some projections are spaced apart or adjacent to each other.

[0076] At least some of the conductive particles 31 have projections that are spaced apart or adjacent to each other along the thickness direction X, indicating that the projections of these conductive particles 31 along the thickness direction X do not overlap. Adjacent means that the edges of two projections can be connected, but they do not overlap. It should be noted that the dashed lines in Figures 7 and 8 represent the projection areas of each conductive particle 31 along the thickness direction X.

[0077] In this embodiment, the projections of at least some of the conductive particles 31 are spaced apart or adjacent to each other. The purpose is to ensure that there are no more than two conductive particles 31 in the projection region along the thickness direction X. This reduces the charge accumulation capacity in the projection region along the thickness direction X, further reducing the probability of partial discharge. Specifically, in some examples, the projections of all conductive particles 31 along the thickness direction X are spaced apart or adjacent to each other.

[0078] This design ensures that no other conductive particles 31 exist in the projection area of ​​the conductive particles 31 along the thickness direction X in the adhesive layer 30, thereby reducing the charge accumulation capacity of the conductive particles 31 in the projection area along the thickness direction X and further reducing the probability of partial discharge.

[0079] According to some embodiments of this application, please refer to Figure 5, 0 < d2 < 0.9 × d1.

[0080] It can be seen that the maximum value of the connection distance d2 of the adhesive layer 30 can be further limited to between 0 and 0.9×d1 (excluding the two endpoint values). For example, d2 can be, but is not limited to, 0.8×d1, 0.7×d1, 0.6×d1, 0.5×d1, etc.

[0081] This design further reduces the size d2 of the conductive particles 31, weakens the influence of the conductive particles on charge accumulation, and reduces the probability of partial discharge.

[0082] According to some embodiments of this application, please refer to Figure 5, 0 < d2 ≤ d1 / 2, and d1 / 4 ≤ d3 < d1.

[0083] The maximum distance d2 between the conductive particles 31 is controlled to be less than or equal to half the thickness of the adhesive layer 30. For example, the maximum distance d2 can be, but is not limited to, d1 / 2, d1 / 3, d1 / 4, d1 / 5, d1 / 6, d1 / 7, d1 / 8, d1 / 9, d1 / 10, etc. The projection of the conductive particles 31 along the thickness direction X is controlled within a certain range, which can reduce the relative area between the conductive particles 31 and the battery cell 10 in the thickness direction X of the adhesive layer 30. At the same time, the minimum distance between the conductive particles 31 and the surface of the adhesive layer 30 facing the battery cell 10 should be controlled to be greater than or equal to one-quarter of the adhesive thickness. For example, the minimum distance d3 can be, but is not limited to, d1 / 4, d1 / 5, d1 / 6, d1 / 7, d1 / 8, d1 / 9, d1 / 10, etc., which can maintain a certain distance between the conductive particles 31 and the battery cell 10.

[0084] Therefore, when the size of the conductive particles 31 is less than or equal to half the thickness of the adhesive, and the distribution position is greater than or equal to one-quarter of the thickness of the adhesive, the charge accumulation of the conductive particles 31 in the electric field can be effectively reduced, thus reducing the probability of partial discharge.

[0085] According to some embodiments of this application, referring to Figures 9 and 10, the battery 100 further includes an insulating film 20. The insulating film 20 covers at least one side of the battery cell 10 facing the adhesive layer 30, and the battery cell 10 is bonded to the adhesive layer 30 through the insulating film 20. The side of the insulating film 20 facing away from the adhesive layer 30 is completely adhered to the side of the battery cell 10 facing the adhesive layer 30.

[0086] The insulating film 20 refers to a structure that provides insulation protection to the surface of the battery cell 10. Its material can be of various types, such as, but not limited to, polypropylene (PP) and polyethylene (PE). The insulating film 20 covers at least one side of the battery cell 10 facing the adhesive layer 30, meaning a portion of the insulating film 20 is positioned between the battery cell 10 and the adhesive layer 30. Of course, the insulating film 20 can also cover other sides of the battery cell 10; for example, in addition to covering the side of the battery cell 10 facing the adhesive layer 30, the insulating film 20 can also cover the circumferential sides of the battery cell 10. It can also cover the side of the battery cell 10 with the end cap 11.

[0087] During the coating process, the insulating film 20 can be completely and tightly adhered to the surface of the battery cell 10, with no air bubbles or other impurities between them; alternatively, some air bubbles or impurities may exist between the insulating film 20 and the surface of the battery cell 10. Of course, in the actual production process, air bubbles or impurities between the insulating film 20 and the battery cell 10 can be minimized. For example, during the coating process, the insulating film 20 and the battery cell 10 can be placed in a vacuum environment.

[0088] "Complete bonding" means that the entire side of the insulating film 20 facing away from the adhesive layer 30 is bonded to the entire side of the battery cell 10, with no air bubbles or impurities between them.

[0089] This design allows one side of the insulating film 20 to be completely adhered to one side of the battery cell 10, ensuring a tight fit between the two, reducing localized adhesion defects, and achieving more effective insulation protection.

[0090] According to some embodiments of this application, referring to Figures 10 and 11, the battery 100 further includes an insulating film 20. The insulating film 20 covers at least one side of the battery cell 10 facing the adhesive layer 30, and the battery cell 10 is bonded to the adhesive layer 30 through the insulating film 20. A protrusion 22 is provided on the side of the insulating film 20 that is bonded to the adhesive layer 30. The protrusion 22 is configured to be formed by an incorporation 21 between the insulating film 20 and the battery cell 10 protruding on the insulating film 20; wherein, the maximum height of the protrusion 22 is denoted as h, and the thickness of the insulating film 20 is denoted as d4, where d4 ≥ h.

[0091] Impurities 21 refer to substances that are mixed into the space between the battery cell 10 and the insulating film 20 when the insulating film 20 is applied to the surface of the battery cell 10, causing a portion of the insulating film 20 to fail to adhere tightly to the battery cell 10. These impurities can be air bubbles, or metallic or non-metallic particles. When air bubbles or impurity particles are introduced between the insulating film 20 and the battery cell 10, the impurities 21 will protrude on the insulating film 20, forming protrusions 22. The larger the size of the impurity 21, the larger the size of the protrusion 22 formed on the insulating film 20. When the impurity 21 is an air bubble or non-metallic particle, such as plastic particles, its dielectric constant is relatively low, making it prone to partial discharge. When the impurity 21 is a metallic particle, it will lead to uneven electric field distribution in the battery cell 10, also easily causing partial discharge.

[0092] In addition, the impurities 21 between the insulating film 20 and the battery cell 10 can easily squeeze the insulating film 20 thinner, resulting in poor insulation performance at that point.

[0093] The maximum height h of the protrusion 22 does not exceed the thickness of the insulating film 20 itself, for example, it can be, but is not limited to, d4, d4 / 2, d4 / 3, d4 / 4, d4 / 5, etc. The thickness of the insulating film 20 itself can be obtained by measuring the thickness of the portion of the insulating film 20 that is in close contact with the battery cell 10 (i.e., the portion not protruding due to the impurity 21). When the insulating film 20 is of uniform thickness, the thickness value of the insulating film 20 can be the thickness value at any point on the portion of the insulating film 20 that is in close contact with the battery cell 10; when the insulating film 20 is of non-uniform thickness, the thickness value of the insulating film 20 can be the average of the thickness values ​​at multiple points on the portion of the insulating film 20 that is in close contact with the battery cell 10. Furthermore, there are various methods for measuring the thickness of the insulating film 20, such as removing the insulating film 20 and measuring it using tools such as a micrometer or caliper.

[0094] It should also be noted that the maximum height h of the protrusion 22 can be understood as: the perpendicular line drawn from the part of the protrusion 22 furthest from the battery cell 10 to the surface of the non-protruding part of the insulating film 20, and the dimension of this perpendicular line is the maximum height h of the protrusion 22. There are several ways to measure the maximum height h of the protrusion 22, such as: acquiring image information of the protrusion 22 and the insulating film 20 by taking a photograph, and then obtaining the maximum height of the protrusion 22 using testing software.

[0095] This design ensures that, in the event of an intrusion 21 between the battery cell 10 and the insulating film 20, the protrusion height of the protrusion 22 does not exceed the thickness of the insulating film 20, which helps to reduce the risk of partial discharge and improve the reliability of the battery 100.

[0096] According to some embodiments of this application, referring to Figures 10 and 11, the thickness d4 satisfies the condition: 0.05mm≤d4≤1mm.

[0097] Within a certain range, the larger the thickness d4 of the insulating film 20, the better the insulation protection effect on the battery cell 10. However, the thickening of the insulating film 20 can easily increase the thickness of the battery cell 10, resulting in excessive occupation of the space between the battery cells 10 and affecting the energy density of the battery 100.

[0098] Therefore, the thickness d4 of the insulating film 20 can be between 0.05mm and 1mm, for example, but not limited to 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.

[0099] This design controls the thickness of the insulating film 20 to between 0.05mm and 1mm, effectively balancing the insulation performance and energy density of the battery 100.

[0100] According to some embodiments of this application, the thickness d4 also satisfies the condition: 0.099mm≤d4≤0.5mm.

[0101] The thickness d4 of the insulating film 20 can be between 0.099mm and 0.5mm, for example, but not limited to 0.099mm, 0.1mm, 0.105mm, 0.11mm, 0.115mm, 0.12mm, 0.14mm, 0.18mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc.

[0102] This design further controls the thickness of the insulating film 20 to between 0.099mm and 0.5mm, making it easier to effectively balance the insulation performance and energy density of the battery 100.

[0103] According to some embodiments of this application, referring to FIG12, the adhesive layer 30 further includes a bubble 32, the projection of the bubble 32 along the thickness direction X of the adhesive layer 30 and the projection of the protrusion 22 along the thickness direction X of the adhesive layer 30 at least partially overlap. Wherein, the adhesive layer 30 further includes a bubble 32, and on the cross-section of the bubble 32 with the largest area perpendicular to the thickness direction X, the maximum distance between any two points on its outer contour line is denoted as d5, where 0 < d5 ≤ 0.3 × d1.

[0104] In the case where, in addition to conductive particles 31, air bubbles 32 are also present in the adhesive layer 30, the projection of the air bubbles 32 along the thickness direction X in the adhesive layer 30 may partially overlap with the projection of the protrusion 22 along the thickness direction X, or it may completely overlap with the projection of the protrusion 22 along the thickness direction X. The overlap between the projection of the air bubbles 32 along the thickness direction X and the projection of the protrusion 22 along the thickness direction X increases the number of locations with low dielectric constants in the same projection area, which easily increases the possibility of partial discharge.

[0105] Therefore, when the projection of bubble 32 overlaps with the projection of protrusion 22, the size of bubble 32 is controlled to not exceed 0.3 times the thickness of adhesive layer 30, such as, but not limited to, 0.3×d1, 0.2×d1, 0.1×d1, 0.05×d1, 0.01×d1, etc., which can reduce the range of partial discharge.

[0106] It is understandable that the edge of the bubble 32 in the adhesive layer 30 is not tangent to the adhesive layer 30. If it were tangent, the bubble 32 would burst and would not be able to form a complete bubble.

[0107] Of course, in some other embodiments, the adhesive layer 30 may contain only conductive particles 31 and no air bubbles 32. For example, when preparing the battery 100, vacuum stirring and mixing, vacuum injection processes, etc., can minimize or even avoid the generation of air bubbles.

[0108] In addition, the projections of the conductive particles 31 in the adhesive layer 30 and the bubbles on the insulating film 20 in the thickness direction X of the adhesive layer 30 can be staggered or partially or completely overlapped, as long as the size of the conductive particles 31 is less than or equal to half the thickness of the adhesive layer 30, and the minimum distance between the conductive particles 31 and the side of the adhesive layer 30 facing the battery cell 10 is greater than or equal to one-quarter of the adhesive thickness.

[0109] According to some embodiments of this application, when the size of the bubble 32 in the adhesive layer 30 does not exceed 0.3 times the thickness of the adhesive layer 30, the projections of the bubble 32 and the protrusion 22 in the thickness direction X can be staggered, or their projections in the thickness direction X can partially or completely overlap. Specifically, in some examples, the maximum line distance d5 of the bubbles 32 does not exceed 0.3 times the thickness of the adhesive layer 30, and the projections of the bubbles 32 along the thickness direction X are separated from or adjacent to the projections of the protrusion 22 along the thickness direction X.

[0110] The maximum line distance d5 can be understood as follows: Several cross-sections are obtained by cutting the bubble 32 with a plane perpendicular to the thickness direction X of the adhesive layer 30. The cross-section with the largest area is selected, and any two points are taken on the outer contour line of this cross-section. The line distance between the two points is then obtained by connecting them. The maximum value among all line distances is taken as the maximum line distance d5 for the bubble 32.

[0111] Of course, if bubble 32 is a sphere or a similar spherical bubble, the maximum distance d5 of the connecting line is the diameter of bubble 32.

[0112] With this design, when there are bubbles 32 in the adhesive layer 30 and the projections of the protrusion 22 and the bubbles 32 overlap in the thickness direction X, the maximum distance d5 between the connecting lines of the bubbles 32 will not exceed 0.3 times the thickness of the adhesive layer 30, reducing the range of partial discharge and improving the reliability of the battery 100.

[0113] According to some embodiments of this application, the adhesive layer 30 also has a bubble 32, the projection of the bubble 32 along the thickness direction X of the adhesive layer 30 and the projection of the protrusion 22 along the thickness direction X of the adhesive layer 30 are spaced apart or adjacent, wherein, on the cross section of the bubble with the largest area perpendicular to the thickness direction, the maximum distance between any two points on its outer contour line is denoted as d5, where 0 < d5 < d1.

[0114] In the case where air bubbles 32 are present in addition to conductive particles 31 in the adhesive layer 30, the air bubbles 32 in the adhesive layer 30 and the protrusions 22 on the insulating film 20 can be staggered. That is, the projection of the air bubble 32 along the thickness direction X and the projection of the protrusion 22 along the thickness direction X do not overlap. This ensures that the protrusion 22 and the air bubble 32 will not coexist on the same path along the thickness direction X. This staggered arrangement ensures that there are no air bubbles 32 in the projection area of ​​the protrusion 22 along the thickness direction in the adhesive layer 30, thereby preventing two locations with low dielectric constants from existing in the projection area of ​​the protrusion 22, reducing the probability of partial discharge. In this case, the size of the air bubbles 32 in the adhesive layer 30 can be controlled to be smaller than the thickness of the adhesive layer 30.

[0115] In this embodiment, adjacency means that the edges of two projections can be connected, but there is no overlap between them. Of course, it can also be understood by referring to the adjacency of the projections between conductive particles 31 in the above embodiment.

[0116] Therefore, when there are bubbles 32 in the adhesive layer 30, controlling the projections of the protrusions 22 and the bubbles 32 in the thickness direction X to be staggered and the size d5 of the bubbles 32 being smaller than the thickness of the adhesive layer 30 can reduce the risk of partial discharge caused by the combined effect of the bubbles 32 and the protrusions 22 in the adhesive layer 30, which is beneficial to improving the reliability of the battery 100.

[0117] According to some embodiments of this application, referring to FIG12, the projections of the bubble 32 along the thickness direction X of the adhesive layer 30 and the projections of each conductive particle 31 along the thickness direction X of the adhesive layer 30 are spaced apart or adjacent. That is, when both the bubble 32 and the conductive particle 31 are present in the adhesive layer 30, the projections of the bubble 32 and the conductive particle 31 along the thickness direction X do not overlap.

[0118] This design allows for reasonable control of the distribution of air bubbles 32 and conductive particles 31 in the adhesive layer 30, further reducing the probability of partial discharge and improving the reliability of the battery 100.

[0119] According to some embodiments of this application, the thickness d1 satisfies the condition: 0.5mm≤d1≤5mm.

[0120] Within a certain range, the larger the thickness d1 of the adhesive layer 30, the better the insulation and protection effect on the battery cell 10. However, the thickening of the adhesive layer 30 can easily increase the height of the battery cell 10, resulting in excessive occupation of the space in the height direction within the battery 100, which affects the energy density of the battery 100.

[0121] Therefore, the thickness d1 of the adhesive layer 30 can be between 0.5mm and 5mm, for example, but not limited to 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0122] Furthermore, when the thickness of the adhesive layer 30 is controlled between 0.5mm and 5mm, the maximum distance d2 between the conductive particles 31 can be less than or equal to 0.25mm or less than or equal to 2.5mm. For example, when the thickness of the adhesive layer 30 is 0.5mm, d2 satisfies 0 < d2 ≤ 0.25mm, and d2 can be, but is not limited to, 0.01mm, 0.04mm, 0.08mm, 0.10mm, 0.15mm, 0.2mm, 0.25mm, etc.; or, when the thickness of the adhesive layer 30 is 5mm, d2 satisfies 0 < d2 ≤ 2.5mm, and d2 can be, but is not limited to, 0.01mm, 0.1mm, 0.5mm, 1.0mm, 1.5mm, 1.8mm, 2.0mm, 2.25mm, 2.5mm, etc. Of course, the maximum value d2 of the connection distance between conductive particles 31 can also be any value between 0.25mm and 2.5mm. Specifically, it can vary according to the actual thickness of the adhesive layer 30.

[0123] This design controls the thickness of the adhesive layer 30 to between 0.5mm and 5mm, effectively balancing the insulation performance and energy density of the battery 100.

[0124] According to some embodiments of this application, the thickness d1 also satisfies the condition: 0.5mm≤d1≤3mm.

[0125] The thickness d1 of the adhesive layer 30 can be between 0.5mm and 3mm, for example, but not limited to 0.5mm, 0.8mm, 1mm, 1.4mm, 1.8mm, 2mm, 2.4mm, 2.6mm, 2.8mm, 3mm, etc.

[0126] This design further controls the thickness of the adhesive layer 30 to between 0.5mm and 3mm, making it easier to effectively balance the insulation performance and energy density of the battery 100.

[0127] According to some embodiments of this application, referring to FIG9, the battery 100 further includes a base 42, and the adhesive layer 30 is disposed on the side facing away from the battery cell 10 on the base 42.

[0128] The base 42 refers to the structure for fixing the battery cell 10. It cooperates with the cover 41 of the battery box 40 to form a receiving space for accommodating the battery cell 10. In some specific examples, the battery 100 includes the battery box 40, the battery box 40 includes the base 42 and the cover 41 covering the base 42, and the battery cell 10 is housed between the cover 41 and the base 42.

[0129] This design incorporates a base 42, which facilitates the stable fixation of the battery cell 10.

[0130] According to some embodiments of this application, this application provides an electrical device, which includes the battery 100 of any of the above.

[0131] According to some embodiments of this application, this application provides an energy storage system, which includes the battery 100 of any of the above.

[0132] In high-voltage energy storage systems, battery 100 is at a high potential relative to ground, exposed to harsh external electromagnetic environments, causing it to operate under strong external electric fields for extended periods. Directly placing a traditional battery 100 in a high-voltage environment would result in higher insulation stress, making it more prone to insulation problems. Therefore, by improving the structure of battery 100, it is possible to enable reliable operation in high-voltage energy storage environments, while also reducing the probability of insulation aging failure and extending system lifespan.

[0133] This design, employing the above-described battery 100 structural design, controls the size and positional distribution of conductive particles 31 in the adhesive layer 30, and / or the size and positional distribution of the protrusions 22 of the insulating film 20 or the bubbles 32 in the adhesive layer 30, thereby reducing the charge accumulation of conductive particles 31 in the adhesive layer 30, and / or controlling the range and distribution of the dielectric constant boundary region, thereby effectively reducing the probability of partial discharge and improving the reliability of the battery 100.

[0134] According to some embodiments of this application, the energy storage system is a high-voltage energy storage system, and its rated voltage is greater than or equal to 1KV.

[0135] The rated voltage of an energy storage system refers to the rated voltage value output by the energy storage system. It can be greater than or equal to 1KV, such as, but not limited to, 1KV, 2KV, 3KV, 6KV, 10KV, 20KV, 30KV, 35KV, 60KV, etc.

[0136] In some embodiments, the rated voltage of the energy storage system may be greater than or equal to 6KV; or, the rated voltage of the energy storage system may be greater than or equal to 35KV.

[0137] With this design, the introduction of the above battery 100 into the high-voltage energy storage system can effectively reduce the probability of partial discharge, improve the reliability of the battery 100, and extend the service life of the energy storage system.

[0138] According to some embodiments of this application, referring to FIG13, the energy storage system includes several cascaded energy storage devices 200; the energy storage device 200 includes a power module 210 and several electrical cabinets 220, the input terminals of the power modules 210 are cascaded to realize the cascading of the energy storage devices 200, and the output terminals of the power modules 210 are connected to all electrical cabinets 220, wherein each electrical cabinet 220 includes several batteries 100 connected in series.

[0139] Power module 210 refers to a component that converts alternating current (AC) and is connected to electrical cabinet 220. When there are multiple electrical cabinets 220, each cabinet 220 can be connected in parallel to the output terminal of power module 210. For example, the output terminal of power module 210 is connected to the positive connection line 230 and the negative connection line 240 respectively, and each electrical cabinet 220 is connected in parallel between the positive connection line 230 and the negative connection line 240. In some embodiments, a main control box 221 is connected between power module 210 and electrical cabinet 220. Furthermore, the batteries 100 in each electrical cabinet 220 include multiple battery cells 10 connected in series. It should be noted that the battery 100 in this embodiment can also be understood as an electrical box.

[0140] Furthermore, the energy storage devices 200, as a whole, are cascaded together. Various cascading methods are possible, such as, but not limited to, star cascading and MMC (modular multilevel converter) cascading. For clarity, please refer to Figure 14. The energy storage system includes an energy storage module 300, which comprises a reactor 310 connected in series and multiple energy storage devices 200. The energy storage module 300 is connected between the positive DC bus 400 and the negative DC bus 410. Additionally, as shown in Figure 14, the energy storage system may also include an isolating switch, a starting resistor, and a starting switch. The starting resistor protects the energy storage system during startup. One end of the isolating switch is connected to the positive DC bus 400, and the other end is connected to one end of the starting resistor and one end of the starting switch. The other ends of both the starting resistor and the starting switch are connected to one end of the reactor 310.

[0141] Meanwhile, referring to Figure 15, in some embodiments, the energy storage system includes an energy storage module 300, which includes a reactor 310 and a plurality of energy storage devices 200 connected in series. The energy storage module 300 includes a plurality of modules, with a portion of the energy storage modules 300 connected in parallel between the positive DC bus 400 and the AC bus 500, and another portion connected in parallel between the negative DC bus 410 and the AC bus 500.

[0142] Additionally, referring to Figure 16, in some other embodiments, the energy storage system includes an energy storage module 300, which includes a reactor 310 and a plurality of energy storage devices 200 connected in series. The energy storage module 300 includes a plurality of modules, one end of which is connected to the AC bus 500, and the other ends are connected to each other.

[0143] This design, by introducing the above-mentioned battery 100 into the high-voltage cascaded energy storage system, can effectively reduce the probability of partial discharge in the high-voltage cascaded energy storage system, which is conducive to improving the reliability of the energy storage system operation.

[0144] According to some embodiments of this application, this application provides a power station, which includes the energy storage system of any of the above.

[0145] According to some embodiments of this application, please refer to Figures 5 to 12. This application provides a battery 100 for use in an energy storage system. The battery 100 includes an insulating film 20, an adhesive layer 30, a battery case 40, and battery cells 10 housed within the battery case 40. The battery case 40 includes a base 42 to which the adhesive layer 30 is bonded and a cover 41 covering the base 42. The insulating film 20 covers the surface of the battery cells 10, and the battery cells 10 are bonded to the adhesive layer 30 through the insulating film 20. The battery 100 can be designed with at least the following structures: 1. The diameter of the conductive particles 31 in the adhesive layer 30 is less than or equal to the thickness of the adhesive layer 30, and the insulating film 20 is completely attached to the bottom surface of the battery cell 10; 2. The diameter of the conductive particles 31 in the adhesive layer 30 is less than or equal to half the thickness of the adhesive layer 30, there are air bubbles between the insulating film 20 and the battery cell 10, the height of the protrusion 22 on the insulating film 20 is less than or equal to the thickness of the insulating film 20, and the diameter of the air bubble 32 in the adhesive layer 30 is less than or equal to 0.3 times the thickness of the adhesive layer 30; 3. The diameter of the conductive particles 31 in the adhesive layer 30 is less than or equal to half the thickness of the adhesive layer 30, there are air bubbles 32 between the insulating film 20 and the battery cell 10, the height of the protrusion 22 on the insulating film 20 is less than or equal to the thickness of the insulating film 20, and there are no air bubbles 32 below the air bubbles on the insulating film 20 in the adhesive layer 30.

[0146] To make the objectives, technical solutions, and advantages of this application clearer and more concise, the following specific embodiments are used for illustration, but this application is by no means limited to these embodiments. The embodiments described below are merely preferred embodiments of this application and can be used to describe this application, but should not be construed as limiting the scope of this application. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

[0147] Example 1

[0148] In the battery 100 structure, on the cross section of the conductive particle 31 (made of aluminum, spherical) with the largest area perpendicular to the thickness direction X, the maximum distance between any two points on its outer contour line is denoted as d2, where d2 is 0.9 mm. The thickness of the adhesive layer 30 is 1 mm. The minimum distance between the surface of the conductive particle 31 facing the adhesive layer 30 and the surface of the adhesive layer 30 facing the battery cell 10 is denoted as d3, where d3 is 0.05 mm. The insulating film 20 (with a thickness of 0.2 mm) is tightly attached to the surface of the battery cell 10, and there are no air bubbles between them. Furthermore, there are no air bubbles 32 in the adhesive layer 30.

[0149] Example 2

[0150] In the battery 100 structure, on the cross-section of the conductive particle 31 (made of aluminum, spherical) with the largest area perpendicular to the thickness direction X, the maximum distance between any two points on its outer contour line is denoted as d2, where d2 is 0.5 mm. The thickness of the adhesive layer 30 is 1 mm. The minimum distance between the surface of the conductive particle 31 facing the adhesive layer 30 and the surface of the adhesive layer 30 facing the battery cell 10 is denoted as d3, where d3 is 0.25 mm. There are air bubbles between the insulating film 20 (with a thickness of 0.2 mm) and the battery cell 10. The ratio of the protrusion height of the protrusion 22 formed by the air bubble on the insulating film 20 to the insulating film 20 is 0.5. The projection of the protrusion 22 along the thickness direction X of the adhesive layer 30 overlaps with half of the projection of the conductive particle 31 along the thickness direction X of the adhesive layer 30. There are no air bubbles 32 in the adhesive layer 30.

[0151] Comparative Example 1

[0152] In the battery 100 structure, on the cross-section of the conductive particle 31 (made of aluminum, spherical) with the largest area perpendicular to the thickness direction X, the maximum distance between any two points on its outer contour line is denoted as d2, where d2 is 0.9 mm. The thickness of the adhesive layer 30 is 1 mm. The minimum distance between the surface of the conductive particle 31 facing the adhesive layer 30 and the surface of the adhesive layer 30 facing the battery cell 10 is denoted as d3, where d3 is 0.05 mm. There are air bubbles between the insulating film 20 (with a thickness of 0.2 mm) and the battery cell 10. The ratio of the protrusion height of the protrusion 22 formed by the air bubble on the insulating film 20 to the insulating film 20 is 0.5. The projection of the protrusion 22 along the thickness direction X of the adhesive layer 30 overlaps half of the projection of the conductive particle 31 along the thickness direction X of the adhesive layer 30. There are no air bubbles 32 in the adhesive layer 30.

[0153] Example 3

[0154] In the battery 100 structure, the maximum distance between any two points on the outer contour line of the conductive particle 31 (made of aluminum, spherical) with the largest area perpendicular to the thickness direction is denoted as d2, where d2 is 0.5 mm. The adhesive layer 30 has a thickness of 1 mm. The minimum distance between the surface of the conductive particle 31 facing the adhesive layer 30 and the surface of the adhesive layer 30 facing the battery cell 10 is denoted as d3, where d3 is 0.25 mm. Air bubbles exist between the insulating film 20 (0.2 mm thick) and the battery cell 10, and the ratio of the protrusion height of the protrusion 22 formed by the air bubbles on the insulating film 20 to the height of the insulating film 20 is 0.5. Air bubbles 32 exist in the adhesive layer 30. The maximum distance between any two points on the outer contour line of the air bubble 32 with the largest area perpendicular to the thickness direction X is denoted as d5, where d5 is 0.3 mm. Meanwhile, the projection of the protrusion 22 along the thickness direction X of the adhesive layer 30 overlaps with half of the projection of the conductive particle 31 along the thickness direction X of the adhesive layer 30 and half of the projection of the bubble 32 in the adhesive layer 30 along the thickness direction X.

[0155] Example 4

[0156] In the battery 100 structure, the maximum distance between any two points on the outer contour line of the conductive particle 31 (made of aluminum, spherical) with the largest area perpendicular to the thickness direction is denoted as d2, where d2 is 0.5 mm. The adhesive layer 30 has a thickness of 1 mm. The minimum distance between the surface of the conductive particle 31 facing the adhesive layer 30 and the surface of the adhesive layer 30 facing the battery cell 10 is denoted as d3, where d3 is 0.25 mm. Air bubbles exist between the insulating film 20 (with a thickness of 0.2 mm) and the battery cell 10, and the ratio of the protrusion height of the protrusion 22 formed by the air bubbles on the insulating film 20 to the height of the insulating film 20 is 0.5. Air bubbles 32 exist in the adhesive layer 30. The maximum distance between any two points on the outer contour line of the air bubble 32 with the largest area perpendicular to the thickness direction X is denoted as d5, where d5 is 0.9 mm. Meanwhile, the projection of the protrusion 22 along the thickness direction X of the adhesive layer 30 overlaps half of the projection of the conductive particle 31 along the thickness direction X of the adhesive layer 30, but does not overlap with the projection of the bubble 32 in the adhesive layer 30 along the thickness direction X.

[0157] Comparative Example 2

[0158] In the battery 100 structure, the maximum distance between any two points on the outer contour line of the conductive particle 31 (made of aluminum, spherical) with the largest area perpendicular to the thickness direction is denoted as d2, where d2 is 0.5 mm. The adhesive layer 30 has a thickness of 1 mm. The minimum distance between the surface of the conductive particle 31 facing the adhesive layer 30 and the surface of the adhesive layer 30 facing the battery cell 10 is denoted as d3, where d3 is 0.25 mm. Air bubbles exist between the insulating film 20 (with a thickness of 0.2 mm) and the battery cell 10, and the ratio of the protrusion height of the protrusion 22 formed by the air bubbles on the insulating film 20 to the height of the insulating film 20 is 0.5. Air bubbles 32 exist in the adhesive layer 30. The maximum distance between any two points on the outer contour line of the air bubble 32 with the largest area perpendicular to the thickness direction X is denoted as d5, where d5 is 0.9 mm. Meanwhile, the projection of the protrusion 22 along the thickness direction X of the adhesive layer 30 overlaps with half of the projection of the conductive particle 31 along the thickness direction X of the adhesive layer 30 and half of the projection of the bubble 32 in the adhesive layer 30 along the thickness direction X.

[0159] The batteries 100 in Examples 1-4 and Comparative Examples 1-2 were simulated using ANSYS software, and the results are shown in Table 1. It should be noted that the maximum electric field strength obtained in Examples 1-4 and Comparative Examples 1-2 is taken from the maximum electric field strength on the insulating film 20.

[0160] Table 1

[0161] As can be seen from Examples 1 and 2, controlling the size d2 of the conductive particles 31 to 0.9d1 when there are no bubbles on the insulating film 20, and controlling the size d2 of the conductive particles 31 to 0.5d1 when there are bubbles on the insulating film 20, can both control the generation of partial discharge. Furthermore, comparing the two examples, it can be inferred that the presence of only conductive particles 31 in the battery 100, compared to the presence of both conductive particles 31 and bubbles in the battery 100, makes it easier to reduce the risk of partial discharge.

[0162] A comparison of Example 2 and Comparative Example 1 shows that when the ratio of the size of the conductive particle 31 to the thickness of the adhesive layer 30 is less than or equal to 0.5, and the minimum distance between the conductive particle 31 and the top surface of the adhesive layer 30 is greater than or equal to 0.4, the partial discharge problem of the battery 100 can be effectively improved. Furthermore, a comparison of Examples 1 and 2 with Comparative Example 1 also shows that as long as the conductive particle 31 meets the above size and position distribution conditions, whether or not its projection along the thickness direction X of the protrusion 22 on the insulating film 20 overlaps with the partial discharge has little impact.

[0163] A comparison of Example 3 and Comparative Example 2 shows that when the maximum distance d5 between the lines connecting the bubbles 32 in the adhesive layer 30 is less than or equal to 0.3 times the thickness of the adhesive layer 30, the probability of partial discharge can be reduced. A comparison of Example 4 and Comparative Example 2 shows that when the projections of the bubbles 32 in the adhesive layer 30 along the thickness direction X and the projections of the protrusions 22 on the insulating film 20 along the thickness direction X are misaligned, the probability of partial discharge can be reduced.

[0164] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0165] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery, the battery comprising: The adhesive layer contains several conductive particles. A single battery cell is disposed on one surface of the adhesive layer along its own thickness direction; Wherein, the thickness of the adhesive layer is denoted as d1, the maximum distance between any two points on the outer contour line of each conductive particle on the cross section with the largest area perpendicular to the thickness direction is denoted as d2, and the minimum distance between the surface of each conductive particle facing the adhesive layer and the surface of the adhesive layer facing the battery cell is denoted as d3, where 0 < d2 < d1 and d3 > 0.

2. The battery according to claim 1, wherein, In the projections of each conductive particle along the thickness direction of the adhesive layer, at least some projections are spaced apart from or adjacent to each other.

3. The battery according to claim 1 or 2, wherein, 0 < d2 < 0.9 × d1.

4. The battery according to claim 3, wherein, 0 < d2 ≤ d1 / 2, and d1 / 4 ≤ d3 < d1.

5. The battery according to any one of claims 1-4, wherein, The battery also includes an insulating film, which covers at least one side of the battery cell facing the adhesive layer, and the battery cell is bonded to the adhesive layer through the insulating film; the side of the insulating film facing away from the adhesive layer is completely in contact with the side of the battery cell facing the adhesive layer.

6. The battery according to any one of claims 1-4, wherein, The battery also includes an insulating film, which covers at least one side of the battery cell facing the adhesive layer. The battery cell is bonded to the adhesive layer through the insulating film. A protrusion is provided on the side of the insulating film bonded to the adhesive layer. The protrusion is configured to be formed by an incorporation between the insulating film and the battery cell protruding on the insulating film. Wherein, the maximum height of the protrusion is denoted as h, and the thickness of the insulating film is denoted as d4, where d4≥h.

7. The battery according to claim 6, wherein, The thickness d4 must satisfy the condition: 0.05mm≤d4≤1mm.

8. The battery according to claim 7, wherein, The thickness d4 also satisfies the condition: 0.099mm≤d4≤0.5mm.

9. The battery according to any one of claims 6-8, wherein, The adhesive layer also contains air bubbles, and the projections of the air bubbles along the thickness direction of the adhesive layer and the projections of the protrusions along the thickness direction of the adhesive layer at least partially overlap. Wherein, on the cross section of the bubble with the largest area perpendicular to the thickness direction, the maximum distance between any two points on its outer contour line is denoted as d5, where 0 < d5 ≤ 0.3 × d1.

10. The battery according to any one of claims 6-8, wherein, The adhesive layer also contains air bubbles. The projection of the air bubble along the thickness direction of the adhesive layer and the projection of the protrusion along the thickness direction of the adhesive layer are spaced apart or adjacent. The maximum distance between any two points on the outer contour line of the air bubble on the cross section with the largest area perpendicular to the thickness direction is denoted as d5, where 0 < d5 < d1.

11. The battery according to claim 9 or 10, wherein, The projections of the bubbles along the thickness direction of the adhesive layer and the projections of each conductive particle along the thickness direction of the adhesive layer are spaced apart or adjacent to each other.

12. The battery according to any one of claims 1-11, wherein, The thickness d1 must satisfy the condition: 0.5mm≤d1≤5mm.

13. The battery according to claim 12, wherein, The thickness d1 also satisfies the condition: 0.5mm≤d1≤3mm.

14. The battery according to any one of claims 1-13, wherein, The battery also includes a base, and the adhesive layer is disposed on the side of the battery cell facing away from the base.

15. An electrical device comprising the battery according to any one of claims 1-14.

16. An energy storage system comprising the battery according to any one of claims 1-14.

17. The energy storage system according to claim 16, wherein, The energy storage system is a high-voltage energy storage system, and its rated voltage is greater than or equal to 1KV.

18. The energy storage system according to claim 16 or 17, wherein, The rated voltage of the energy storage system is greater than or equal to 6KV.

19. The energy storage system according to any one of claims 16-18, wherein, The rated voltage of the energy storage system is greater than or equal to 35KV.

20. The energy storage system according to any one of claims 16-19, wherein, The energy storage system includes several cascaded energy storage devices; The energy storage device includes a power module and several electrical cabinets. The input terminals of the power modules are cascaded to realize the cascading of the energy storage device. The output terminals of the power modules are connected to all the electrical cabinets. Each electrical cabinet includes several batteries connected in series.

21. A power station comprising the energy storage system according to any one of claims 16-20.

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