Battery monomer, battery device, energy storage device and electric equipment

Abstract

The utility model relates to the technical field of battery equipment, and discloses a battery monomer, a battery device, an energy storage device and electric equipment. The battery cell comprises: a housing having an accommodating space; an electrode assembly accommodated in the accommodation space; the pressure relief mechanism is arranged on the side wall of the shell; the protective layer is arranged on the inner side of the side wall, provided with the pressure relief mechanism, of the shell, the projection of the protective layer at least covers the circumferential edge area of the pressure relief mechanism in the direction from the electrode assembly to the pressure relief mechanism, the protective layer is provided with an overflowing channel, the overflowing channel is arranged opposite to at least part of the pressure relief area of the pressure relief mechanism, and the pressure relief mechanism is arranged in the overflowing channel. The protective layer and the electrode assembly are arranged at intervals. The technical scheme includes but is not limited to solving the problem that thermal runaway of the single battery easily causes ablative crevasse of the pressure relief mechanism and the shell in the circumferential area of the pressure relief mechanism and thermal diffusion.

Description

Technical Field

[0001] This application belongs to the field of battery equipment technology, and in particular relates to a battery cell, battery device, energy storage device and electrical equipment. Background Technology

[0002] With the continuous development of battery technology, the energy density of individual battery cells is constantly increasing. In battery devices using related technologies, when one or more individual battery cells experience thermal runaway, the high energy density of these cells leads to violent electrochemical reactions within them, generating a large amount of high-temperature flue gas. This high-temperature flue gas gradually creates relatively high pressure inside the battery cell, actuating the cell's pressure relief mechanism to release the high-temperature flue gas. This flue gas mixes with air and ignites. As the high-temperature flue gas continues to be released and burned through the pressure relief mechanism, it can easily cause ablation and breaches in the casing around the mechanism. This can then affect other battery cells within the device, causing thermal diffusion and ultimately resulting in a multi-level thermal runaway of the entire battery device. Utility Model Content

[0003] The purpose of this application is to provide a battery cell, battery device, energy storage device, and electrical equipment, including but not limited to solving the problem that thermal runaway of a battery cell can easily lead to thermal diffusion caused by ablation of the pressure relief mechanism and the casing of the circumferential area of ​​the pressure relief mechanism.

[0004] To achieve the above objectives, according to a first aspect of an embodiment of this application, a battery cell is provided, comprising:

[0005] The shell has a storage space;

[0006] Electrode assembly, housed within the housing space;

[0007] The pressure relief mechanism is located on one of the side walls of the housing. The pressure relief mechanism can communicate with the containment space when the electrode assembly experiences thermal runaway.

[0008] A protective layer is disposed on the inner side of the side wall of the housing with the pressure relief mechanism. Along the direction from the electrode assembly to the pressure relief mechanism, the projection of the protective layer covers at least the circumferential edge area of ​​the pressure relief mechanism. The protective layer is provided with a flow channel, which is disposed opposite to at least a portion of the pressure relief area of ​​the pressure relief mechanism. Furthermore, the protective layer is spaced apart from the electrode assembly.

[0009] In the battery cell of the embodiments of this application, a protective layer is provided on the inner side of the side wall of the battery cell housing where the pressure relief mechanism is provided. Along the direction from the electrode assembly of the battery cell to the pressure relief mechanism, the projection of the protective layer at least covers the circumferential edge region of the pressure relief mechanism. Furthermore, the protective layer is provided with a flow channel, which is disposed opposite to at least a portion of the pressure relief region of the pressure relief mechanism. Thus, when the battery cell experiences thermal runaway and generates high-temperature flue gas, the high-temperature flue gas can flow through the flow channel to reach the pressure relief mechanism, actuating and opening the pressure relief mechanism to relieve pressure inside the battery cell. Because of the protective layer, when the high-temperature flue gas is ejected from the pressure relief mechanism, it first impacts the protective layer, thereby reducing the impact of the high-temperature flue gas on the pressure relief mechanism and the housing of the circumferential edge region of the pressure relief mechanism during injection. This effectively reduces the ablation of the pressure relief mechanism and the casing of the circumferential edge area by high-temperature flue gas, thereby controlling the impact of thermal runaway on the battery cell to a certain extent, reducing the probability of thermal diffusion, reducing the probability of thermal runaway at the entire battery device level, and improving the safety of the battery device.

[0010] In some embodiments of this application, along the direction from the electrode assembly to the pressure relief mechanism, the projection of the protective layer coincides with the projection of the side wall of the housing where the pressure relief mechanism is located. When a single battery cell experiences thermal runaway and generates high-temperature flue gas, the high-temperature flue gas contacts the protective layer and transfers heat. The protective layer can slow down the rate at which the high-temperature flue gas transfers heat to the side wall of the housing where the pressure relief mechanism is located, thereby slowing down the rate at which the side wall is heated and softened.

[0011] In some embodiments of this application, the flow channel is positioned directly opposite the pressure relief area of ​​the pressure relief mechanism. This allows the pressure relief mechanism to respond quickly and open actuated, improving the pressure relief response efficiency.

[0012] In some embodiments of this application, the protective layer is a component made of mica, carbon fiber, graphite copper, aerogel, or ceramic plate. The resulting protective layer has a low thermal conductivity and good strength and toughness.

[0013] In some embodiments of this application, the thickness of the protective layer ranges from 0.5 mm to 5.0 mm. This ensures that the protective layer has sufficient strength and toughness as well as good thermal insulation and temperature resistance, and optimizes and reduces the impact of the protective layer on the energy density of the battery cells.

[0014] In some embodiments of this application, the protective layer is bonded to the sidewall of the housing using structural adhesive. Bonding with structural adhesive ensures a stable connection between the protective layer and the sidewall of the housing.

[0015] In some embodiments of this application, the housing includes a housing body and a housing cover, the housing cover being fitted onto the housing body to form an accommodating space, the battery cell also includes an electrode post structure, the pressure relief mechanism and the electrode post structure are both disposed on the housing cover, the electrode post structure is electrically connected to the tabs of the electrode assembly, and a protective layer is disposed on the inner side of the housing cover.

[0016] In some embodiments of this application, the protective layer is further provided with through holes, through which the tabs of the electrode assembly pass to be electrically connected to the electrode post structure. The connection between the tabs of the electrode assembly and the electrode post structure via the through holes utilizes the shortest possible routing path, thereby reducing the length of the tabs, saving space occupied by the tabs, and saving materials.

[0017] In some embodiments of this application, the housing includes a housing body and a housing cover, the housing cover being closed to the housing body to form an accommodating space, the battery cell also includes an electrode post structure, the electrode post structure being disposed on the housing cover, the electrode post structure being electrically connected to the electrode tabs of the electrode assembly, a pressure relief mechanism being disposed on the bottom wall of the housing body opposite to the housing cover, and a protective layer being disposed on the inner side of the bottom wall of the housing body.

[0018] In some embodiments of this application, the housing includes a housing body, a first housing cover, and a second housing cover. The first housing cover and the second housing cover respectively cover the two ends of the housing body to form an accommodating space. The battery cell also includes a positive terminal and a negative terminal. The positive terminal and the negative terminal are respectively disposed on the first housing cover and the second housing cover. The positive terminal is electrically connected to the positive terminal tab of the electrode assembly, and the negative terminal is electrically connected to the negative terminal tab of the electrode assembly. A pressure relief mechanism is disposed on one side wall of the housing body, and a protective layer is disposed on the inner side of the side wall of the housing body where the pressure relief mechanism is located.

[0019] According to a second aspect of an embodiment of this application, a battery device is provided. The battery device includes a battery cell as described above, the battery cell being used to store or provide electrical energy.

[0020] According to a third aspect of the embodiments of this application, an energy storage device is provided. Wherein:

[0021] The energy storage device includes battery cells as described above, which are used to store or provide electrical energy;

[0022] Alternatively, the energy storage device may include a battery device as described above, which is used to store or provide electrical energy.

[0023] According to a fourth aspect of an embodiment of this application, an electrical appliance is provided. The electrical appliance includes an electrical load; and,

[0024] The electrical equipment also includes multiple battery cells as described above, and the electrical load is electrically connected to the multiple battery cells;

[0025] Alternatively, the electrical equipment may also include a battery device as described above, with the electrical load electrically connected to the battery device;

[0026] Alternatively, the electrical equipment may also include an energy storage device as described above, with the electrical load electrically connected to the energy storage device. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is an exploded view of a battery device according to an embodiment of this application;

[0029] Figure 2 This is an exploded view of a battery cell according to an embodiment of this application;

[0030] Figure 3 for Figure 2 A top view of a single battery cell is shown.

[0031] Figure 4 for Figure 3 Cross-sectional view along the AA direction;

[0032] Figure 5 for Figure 2 The diagram shows the assembly structure of the battery cell's casing, protective layer, and terminal post.

[0033] Figure 6 for Figure 2 A schematic diagram of the protective layer structure of a single battery cell is shown.

[0034] Figure 7 This is a cross-sectional schematic diagram of another battery cell according to an embodiment of this application;

[0035] Figure 8 for Figure 7 A schematic diagram of the protective layer structure of a single battery cell is shown.

[0036] Figure 9 This is an exploded view of another battery cell according to an embodiment of this application;

[0037] Figure 10 This is a schematic diagram of the assembly structure of an energy storage device according to an embodiment of this application;

[0038] Figure 11 This is a schematic diagram of the assembly structure of an electrical device according to an embodiment of this application.

[0039] The figures in the diagram are labeled as follows:

[0040] 100. Battery cell;

[0041] 10. Shell; 11. Shell body; 111. Bottom wall; 112. Side wall; 12. Shell cover; 13. First shell cover; 14. Second shell cover; 15. Accommodation space;

[0042] 20. Electrode assembly; 21. Tab; 211. Positive tab; 212. Negative tab;

[0043] 30. Pressure relief mechanism;

[0044] 40. Protective layer; 41. Flow channel; 42. Through hole; 43. Structural adhesive;

[0045] 50. Terminal structure; 51. Positive terminal; 52. Negative terminal;

[0046] 200. Battery assembly; 201. Box body; 202. Box cover; 203. Assembly space;

[0047] 300. Energy storage device; 301. Cabinet;

[0048] 400. Electrical equipment; 410. Electrical load; 420. Control device; 430. Chassis; 440. Wheel. Detailed Implementation

[0049] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0050] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., 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.

[0051] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0053] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants (battery devices used in these applications are generally referred to as energy storage batteries), but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace (battery devices used in these applications are generally referred to as power batteries). With the continuous expansion of the application fields of battery devices, users' requirements for the safety of battery devices are also constantly increasing.

[0054] In related technologies, with the continuous development of battery technology, the energy density of individual battery cells is constantly increasing. In battery devices of this technology, when one or more individual battery cells experience thermal runaway, the high energy density of the individual cells leads to violent electrochemical reactions within them, generating a large amount of high-temperature flue gas. This large amount of high-temperature flue gas gradually creates relatively high pressure inside the battery cell, actuating the pressure relief mechanism to release the high-temperature flue gas. This flue gas mixes with air and ignites. As the high-temperature flue gas continues to be released and burned from the pressure relief mechanism, it can easily cause ablation and breaches in the casing of the pressure relief mechanism and its surrounding area. This can then affect other battery cells within the device, causing thermal diffusion and ultimately resulting in cascading thermal runaway of the entire battery device.

[0055] Ablation refers to the phenomenon in which an object undergoes a series of physical and chemical changes such as melting, evaporation, sublimation, oxidation, and erosion under high temperature, high-speed airflow, or other high-energy conditions. Objects may undergo thermal decomposition, oxidation, or combustion reactions under high temperature conditions.

[0056] Based on the above considerations, embodiments of this application provide a battery cell, and an assembly method using this battery cell to produce battery devices, energy storage devices, and electrical equipment. In the battery cell of this application, a protective layer is provided on the inner side of the sidewall of the battery cell housing where a pressure relief mechanism is located. Along the direction from the electrode assembly of the battery cell to the pressure relief mechanism, the projection of the protective layer at least covers the circumferential edge region of the pressure relief mechanism. Furthermore, the protective layer has a flow channel, which is positioned opposite to at least a portion of the pressure relief region of the pressure relief mechanism. Thus, when the battery cell experiences thermal runaway and generates high-temperature flue gas, the high-temperature flue gas can flow through the flow channel to reach the pressure relief mechanism, actuating and opening the pressure relief mechanism to relieve pressure inside the battery cell. Because of the protective layer, when the high-temperature flue gas is ejected from the pressure relief mechanism, it first impacts the protective layer, thereby reducing the impact of the high-temperature flue gas on the pressure relief mechanism and the housing of the circumferential edge region of the pressure relief mechanism during ejection. This effectively reduces the ablation of the pressure relief mechanism and the casing of the circumferential edge area by high-temperature flue gas, thereby controlling the impact of thermal runaway on the battery cell to a certain extent, reducing the probability of thermal diffusion, reducing the probability of thermal runaway at the entire battery device level, and improving the safety of the battery device.

[0057] To illustrate the technical solutions provided by the embodiments of this application, the following detailed description is provided in conjunction with specific drawings and embodiments.

[0058] According to a first aspect of the embodiments of this application, embodiments of this application provide a battery cell 100. For example... Figures 2 to 9 As shown, the battery cell 100 includes a housing 10, an electrode assembly 20, a pressure relief mechanism 30, and a protective layer 40. The housing 10 has a receiving space 15, in which the electrode assembly 20 is received. The pressure relief mechanism 30 is disposed on one of the side walls of the housing 10, and can communicate with the receiving space 15 when the electrode assembly 20 experiences thermal runaway. The protective layer 40 is disposed on the inner side of the side wall of the housing 10 where the pressure relief mechanism 30 is located. Along the direction from the electrode assembly 20 to the pressure relief mechanism 30, the projection of the protective layer 40 at least covers the circumferential edge region of the pressure relief mechanism 30. The protective layer 40 has a flow channel 41, which is disposed opposite to at least a portion of the pressure relief region of the pressure relief mechanism 30. Furthermore, the protective layer 40 is spaced apart from the electrode assembly 20.

[0059] In the battery cell 100 of the embodiments of this application, a protective layer 40 is provided on the inner side of the side wall of the housing 10 of the battery cell 100 where the pressure relief mechanism 30 is provided. Along the direction from the electrode assembly 20 of the battery cell 100 to the pressure relief mechanism 30, the projection of the protective layer 40 at least covers the circumferential edge region of the pressure relief mechanism 30. Furthermore, the protective layer 40 is provided with a flow channel 41, which is disposed opposite to at least a portion of the pressure relief region of the pressure relief mechanism 30. Thus, when the battery cell 100 experiences thermal runaway and generates high-temperature flue gas, because the protective layer 40 is spaced apart from the electrode assembly 20, it does not obstruct the flow of the high-temperature flue gas to the pressure relief mechanism 30. The high-temperature flue gas can flow smoothly through the flow channel 41 to reach the pressure relief mechanism 30, causing the pressure relief mechanism 30 to open and thereby relieving pressure inside the battery cell 100. Because of the protective layer 40, when the high-temperature flue gas is ejected from the pressure relief mechanism 30, it first impacts the protective layer 40, thereby reducing the impact of the high-temperature flue gas on the pressure relief mechanism 30 and the casing 10 at its circumferential edge. This effectively reduces the degree of ablation of the high-temperature flue gas on the pressure relief mechanism 30 and the casing 10 at its circumferential edge, thus controlling the impact of thermal runaway on the battery cell 100 to a certain extent, reducing the probability of thermal diffusion, reducing the probability of thermal runaway at the entire battery device 200 level, and improving the safety of the battery device 200.

[0060] The pressure relief mechanism 30 refers to an element or component that is activated to release internal pressure when the internal pressure or temperature of the battery cell 100 reaches a predetermined threshold. "Activation" means that the pressure relief mechanism 30 performs an action, thereby releasing the internal pressure and temperature of the battery cell 100. The action of the pressure relief mechanism 30 may include, but is not limited to, at least a portion of the pressure relief mechanism 30 rupturing, tearing, or melting. After activation, the high-temperature flue gas inside the battery cell 100 will be discharged outward from the pressure relief mechanism 30. The predetermined threshold can be adjusted according to different design requirements. The predetermined threshold may depend on one or more of the materials of the positive electrode, negative electrode, separator, and electrolyte of the electrode assembly 20 in the battery cell 100. The pressure relief mechanism 30 may employ elements or components that are sensitive to pressure or temperature; that is, when the internal pressure or temperature of the battery cell 100 reaches the predetermined threshold, the pressure relief mechanism 30 is activated, thereby forming a channel for releasing internal pressure (i.e., the pressure relief area of ​​the pressure relief mechanism 30).

[0061] In the embodiments of this application, the battery cell 100 can be a secondary battery, which refers to a battery cell 100 that can be recharged after discharge to activate the active materials and continue to be used. The battery cell 100 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0062] Furthermore, the battery cell 100 provided in the embodiments of this application can be a square battery cell, also known as a square cell. Of course, the battery cell 100 can also be a cylindrical battery cell, also known as a cylindrical cell. The following description uses a square cell as an example, and the cylindrical cell can be referred to the square cell, and will not be repeated here.

[0063] The casing 10 of the square battery cell 100 has two large sidewalls with larger surface areas, two small sidewalls with smaller surface areas, a bottom wall, and a top wall. The two large sidewalls and the two small sidewalls are alternately connected to form prism-shaped sidewalls, and the bottom wall and the top wall are located at the upper and lower ends of the prism-shaped sidewalls, respectively.

[0064] In some embodiments of this application, along the direction from the electrode assembly 20 to the pressure relief mechanism 30, the projection of the protective layer 40 coincides with the projection of the side wall of the housing 10 where the pressure relief mechanism 30 is located. That is, the inner side of the side wall of the housing 10 where the pressure relief mechanism 30 is located is completely covered by the protective layer 40. When the battery cell 100 experiences thermal runaway and generates high-temperature flue gas, the high-temperature flue gas contacts the protective layer 40. The protective layer 40 can slow down the heat transfer rate of the high-temperature flue gas to the side wall of the housing 10 where the pressure relief mechanism 30 is located, thereby slowing down the rate at which the side wall is heated and softened. Furthermore, in embodiments of this application, the protective layer 40 has heat insulation and temperature resistance properties. In this way, when the battery cell 100 experiences thermal runaway and generates high-temperature flue gas, since the protective layer 40 is located on the inner side of the side wall of the housing 10 where the pressure relief mechanism 30 is located, and the projection of the protective layer 40 coincides with the projection of the side wall of the housing 10 where the pressure relief mechanism 30 is located, most of the heat of the high-temperature flue gas is blocked by the protective layer 40 and cannot be transferred to the side wall of the housing 10 where the pressure relief mechanism 30 is located. This effectively reduces the temperature rise of the side wall of the housing 10 where the pressure relief mechanism 30 is located, and also reduces the degree to which the side wall is heated and softened. In this way, during the process of high-temperature flue gas being ejected from the pressure relief mechanism 30, the high-speed flowing high-temperature flue gas first impacts the protective layer 40, thereby reducing the impact of the high-temperature flue gas on the pressure relief mechanism 30 and the shell 10 of the circumferential edge area of ​​the pressure relief mechanism 30. Furthermore, the sidewall that is insulated by the protective layer 40 and has a lower temperature rise is more able to withstand the impact of the ejected high-temperature flue gas than the sidewall that is heated and softened. This effectively reduces the degree of ablation of the high-temperature flue gas on the pressure relief mechanism 30 and the shell 10 of the circumferential edge area of ​​the pressure relief mechanism 30, thereby controlling the degree of thermal runaway of the battery cell 100 to a certain extent, reducing the probability of thermal diffusion, reducing the probability of thermal runaway at the entire battery device 200 level, and improving the safety of the battery device 200.

[0065] In some embodiments of the battery cell 100 of this application, the flow channel 41 is positioned directly opposite the pressure relief area of ​​the pressure relief mechanism 30. Along the direction from the electrode assembly 20 to the pressure relief mechanism 30, the projected range of the flow channel 41 can be larger than the projected range of the pressure relief area of ​​the pressure relief mechanism 30, or the projected range of the flow channel 41 can be equal to the projected range of the pressure relief area of ​​the pressure relief mechanism 30, or the projected range of the flow channel 41 can be smaller than the projected range of the pressure relief area of ​​the pressure relief mechanism 30. Preferably, in the embodiments of this application, the projected range of the flow channel 41 is equal to the projected range of the pressure relief area of ​​the pressure relief mechanism 30. Thus, when the battery cell 100 experiences thermal runaway and generates high-temperature flue gas, as the high-temperature flue gas flows through the flow channel 41 of the protective layer 40 to the pressure relief mechanism 30, because the flow channel 41 is directly opposite the pressure relief area of ​​the pressure relief mechanism 30, the high-temperature flue gas flowing through the flow channel 41 can fully act on the pressure relief mechanism 30. In other words, compared to the case where the flow channel 41 and the pressure relief mechanism 30 are partially arranged opposite each other, the case where the flow channel 41 and the pressure relief mechanism 30 are directly opposite each other within the same time interval allows for a larger flow rate of high-temperature flue gas acting on the pressure relief mechanism 30, and a more sufficient force on the pressure relief mechanism 30, thereby enabling the pressure relief mechanism 30 to respond quickly and open actuated, thus improving the pressure relief response efficiency.

[0066] In some embodiments of the battery cell 100 of this application, the protective layer 40 is a component made of mica, carbon fiber, graphite copper, aerogel, or ceramic plate. Thus, the resulting protective layer 40 has a low thermal conductivity, meaning it possesses heat insulation and temperature resistance properties, can withstand the high temperature of the flue gas, and to a certain extent blocks heat transfer to the sidewall of the housing 10 where the pressure relief mechanism 30 is located. Furthermore, the resulting protective layer 40 has good strength and toughness, which helps the sidewall of the housing 10 with the pressure relief mechanism 30 withstand the high pressure generated by the high-temperature flue gas inside the battery cell 100, reducing the probability of the housing 10 being cracked due to expansion at the circumferential edge area of ​​the pressure relief mechanism 30, and protecting the integrity of the sidewall of the housing 10 with the pressure relief mechanism 30.

[0067] To minimize the space occupied by the protective layer 40 after it is assembled into the receiving space 15, and to minimize the impact of the protective layer 40 on the energy density of the battery cell 100, the thickness of the protective layer 40 in this embodiment is 0.5mm-5.0mm, while ensuring that the protective layer 40 has sufficient strength and toughness as well as good heat insulation and temperature resistance. Preferably, the thickness of the protective layer 40 is 0.5mm-2.0mm. In this embodiment, the thickness of the protective layer 40 is preferably 1.0mm. This ensures that the protective layer 40 has sufficient strength and toughness as well as good heat insulation and temperature resistance, and optimizes and reduces the impact of the protective layer 40 on the energy density of the battery cell 100.

[0068] In some embodiments of the battery cell 100 of this application, the protective layer 40 is bonded to the sidewall of the housing 10 using structural adhesive 43 to improve the assembly efficiency of the assembled battery cell 100. The structural adhesive 43 is a high-strength, high-viscosity adhesive with excellent heat resistance, media resistance, aging resistance, and vibration fatigue resistance. Therefore, bonding with structural adhesive 43 ensures a stable connection between the protective layer 40 and the sidewall of the housing 10.

[0069] In some embodiments of the battery cell 100 of this application, such as Figure 2 and Figure 4 As shown, the housing 10 includes a main body 11 and a cover 12. The cover 12 closes onto the main body 11 to form an accommodating space 15. The circumferential sidewalls 112 of the main body 11 are the two large sidewalls and two small sidewalls alternately connected to form prismatic sidewalls. The bottom wall 111 of the main body 11, opposite the cover 12, is the bottom end wall of the battery cell 100. In other words, the main body 11 is an integrally formed component with an open end and a closed end, and the cover 12 is the top end wall of the battery cell 100. Figures 2 to 5 As shown, the battery cell 100 also includes a terminal post structure 50. Both the pressure relief mechanism 30 and the terminal post structure 50 are disposed on the housing cover 12. The terminal post structure 50 is electrically connected to the tabs 21 of the electrode assembly 20. A protective layer 40 is disposed on the inner side of the housing cover 12. In other words, the battery cell 100 of this embodiment is a top-spray design type battery cell where the housing cover 12 and the pressure relief mechanism 30 are disposed on the same side relative to the electrode assembly 20.

[0070] In order to reduce the length of the tabs 21 of the electrode assembly 20, save the space occupied by the tabs 21 and save materials, in some embodiments of this application, such as Figure 2 , Figure 5 and Figure 6As shown, the protective layer 40 also has a through hole 42, which is directly opposite to the electrode post structure 50. The electrode tab 21 of the electrode assembly 20 passes through the through hole 42 and is electrically connected to the electrode post structure 50. Since the shortest distance between two points is a straight line, the electrode tab 21 of the electrode assembly 20 is electrically connected to the electrode post structure 50 through the through hole 42 using the shortest routing path, thereby reducing the length of the electrode tab 21, saving space and materials. Furthermore, the electrode tab 21 of the electrode assembly 20 does not require adaptation or deformation before routing; it can be directly connected to the electrode post structure 50 by passing the electrode tab 21 through the through hole 42, resulting in high assembly efficiency.

[0071] In some embodiments of the battery cell 100 of this application, such as Figure 7 and Figure 8 As shown, the housing 10 includes a main body 11 and a cover 12. The cover 12 closes onto the main body 11 to form an accommodating space 15. The circumferential sidewalls 112 of the main body 11 are the two large sidewalls and two small sidewalls alternately connected to form prismatic sidewalls. The bottom wall 111 of the main body 11, opposite the cover 12, is the bottom wall of the battery cell 100, and the cover 12 is the top wall of the battery cell 100. Figure 7 and Figure 8 As shown, the battery cell 100 also includes a terminal structure 50, which is disposed on the housing cover 12 and electrically connected to the tabs 21 of the electrode assembly 20. A pressure relief mechanism 30 is disposed on the bottom wall 111 of the housing body 11 opposite to the housing cover 12, and a protective layer 40 is disposed on the inner side of the bottom wall 111 of the housing body 11. That is, the battery cell 100 in this embodiment is a bottom-spray design type battery cell in which the housing cover 12 and the pressure relief mechanism 30 are disposed on different sides of the electrode assembly 20.

[0072] In some embodiments of the battery cell 100 of this application, such as Figure 9 As shown, the housing 10 includes a main body 11, a first cover 13, and a second cover 14. The first cover 13 and the second cover 14 respectively cover the two ends of the main body 11 to form an accommodating space 15. The circumferential sidewalls 112 of the main body 11 are the two large sidewalls and two small sidewalls alternately connected to form a prismatic sidewall. The first cover 13 is the bottom wall of the battery cell 100, and the second cover 14 is the top wall of the battery cell 100. Figure 9As shown, the battery cell 100 also includes a positive electrode post 51 and a negative electrode post 52. The positive electrode post 51 and the negative electrode post 52 are respectively disposed on the first housing cover 13 and the second housing cover 14. The positive electrode post 51 is electrically connected to the positive electrode tab 211 of the electrode assembly 20, and the negative electrode post 52 is electrically connected to the negative electrode tab 212 of the electrode assembly 20. The pressure relief mechanism 30 is disposed on one side wall of the housing body 11, and the protective layer 40 is disposed on the inner side of the side wall 112 of the housing body 11 where the pressure relief mechanism 30 is located. That is, the battery cell 100 of this embodiment is a bottom-sprayed design type battery cell in which the positive electrode post 51 and the negative electrode post 52 are located on different sides of the electrode assembly 20, and the positive electrode post 51, the negative electrode post 52, and the pressure relief mechanism 30 are all disposed on different sides.

[0073] According to a second aspect of the embodiments of this application, the embodiments of this application also provide a battery device 200, which will be described below using a prismatic cell assembly to form the battery device 200 (i.e., a prismatic battery). The implementation scheme using cylindrical cells for assembly to form the battery device 200 can be specifically referred to the implementation scheme using prismatic cells for assembly to form the battery device 200, and will not be repeated here.

[0074] like Figure 1 As shown, the battery device 200 includes a main body 201, a cover 202, and multiple battery cells 100 as described above. The cover 202 closes onto the open end of the main body 201, and the main body 201 and the cover 202 together form an assembly space 203. The multiple battery cells 100 are arrayed and assembled within the assembly space 203. The battery cells 100 are used to store electrical energy or supply power.

[0075] In the battery device 200 using battery cells 100, a protective layer 40 is provided on the inner side of the side wall of the housing 10 of the battery cell 100 where the pressure relief mechanism 30 is located. Along the direction from the electrode assembly 20 of the battery cell 100 to the pressure relief mechanism 30, the projection of the protective layer 40 at least covers the circumferential edge region of the pressure relief mechanism 30. Furthermore, the protective layer 40 is provided with a flow channel 41, which is positioned opposite to at least a portion of the pressure relief region of the pressure relief mechanism 30. Thus, when the battery cell 100 experiences thermal runaway and generates high-temperature flue gas, the high-temperature flue gas can flow through the flow channel 41 to reach the pressure relief mechanism 30, actuating and opening the pressure relief mechanism 30 to relieve pressure inside the battery cell 100. Because of the protective layer 40, when the high-temperature flue gas is ejected from the pressure relief mechanism 30, it first impacts the protective layer 40, thereby reducing the impact of the high-temperature flue gas on the pressure relief mechanism 30 and the housing 10 of the circumferential edge region of the pressure relief mechanism 30 during ejection. This can effectively reduce the degree of ablation of the pressure relief mechanism 30 and the shell 10 of the circumferential edge area of ​​the pressure relief mechanism 30 by high temperature flue gas, thereby controlling the degree of thermal runaway of the battery cell 100 that has experienced thermal runaway to a certain extent, reducing the probability of thermal diffusion, reducing the probability of thermal runaway at the entire battery device 200 level, and improving the safety of the battery device 200.

[0076] According to a third aspect of the embodiments of this application, embodiments of this application also provide an energy storage device 300. In some embodiments of this application, the energy storage device 300 includes a battery device 200 as described above, that is, the energy storage device 300 uses one battery device 200 or multiple battery devices 200 connected in series, parallel, or mixed, such that these battery devices 200 are used to store electrical energy or provide electrical energy. In other embodiments of this application, the energy storage device 300 includes multiple battery cells 100 as described above, that is, the energy storage device 300 uses multiple battery cells 100 connected in series, parallel, or mixed, such that these battery cells 100 are used to store electrical energy or provide electrical energy.

[0077] The energy storage device 300 can be a small, portable device, such as a convenient energy storage battery used for outdoor tourism and camping, or a portable energy storage battery used by street vendors. The energy storage device 300 can also be a large, fixed, high-power industrial-grade device, such as a large energy storage power station used in a power plant. The energy storage device 300 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. The energy storage device 300 can store electrical energy as needed and output it when appropriate. For example, the energy storage device 300 can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. Other examples include independent power supply energy storage cabinets or energy storage containers used on construction sites or in factories, and larger, portable energy storage cabinets or energy storage containers used at large event venues.

[0078] like Figure 10 As shown, the energy storage device 300 provided in the embodiments of this application is preferably an energy storage cabinet, which includes a cabinet 301 and a plurality of battery devices 200, which are stacked and assembled in the cabinet 301.

[0079] In some embodiments of this application, the energy storage device 300 may include modules such as a thermal management module, a main control module, a central control module, a power distribution module, and a fire protection module.

[0080] As an example, the thermal management module may include a liquid cooling unit that supplies coolant to each battery cell 100 or each battery device 200 via pipelines for regulating the temperature of the battery cell 100.

[0081] As an example, the main control module can serve as a battery management unit for multiple battery cells 100 or multiple battery devices 200, used to monitor and manage these cells. The main control module can monitor information such as current, voltage, power, or temperature of the multiple battery cells 100 or multiple battery devices 200. For example, it can control the charging and discharging current and voltage of the multiple battery cells 100 or multiple battery devices 200. The main control module includes modules such as an auxiliary battery management unit (SBMU) and a fusion switch.

[0082] As an example, the central control module can serve as the battery management unit of the energy storage device 300, used to monitor and manage the energy storage device 300. The central control module can monitor information such as the current, voltage, power, state of charge, or temperature of the energy storage device 300. For example, it can control the charging and discharging current and voltage of the energy storage device 300. As an example, the central control module includes modules such as an insulation monitoring module (IMM), a master battery management unit (MBMU), an Ethernet (ETH) module, and a fiber optic conversion module.

[0083] As an example, the fire protection module includes a control panel, detectors, alarm devices, etc., used to detect, alarm, or extinguish fires in the energy storage system.

[0084] As an example, the power distribution module can be used to distribute power to the modules in the energy storage device 300 that require electricity.

[0085] According to a fourth aspect of the embodiments of this application, embodiments of this application also provide an electrical appliance 400, which includes an electrical load 410.

[0086] Electrical equipment 400 includes, but is not limited to, electric toys, power tools, electric vehicles, electric cars, ships, and spacecraft. Electric toys may include, but are not limited to, stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Spacecraft may include, but are not limited to, airplanes, rockets, space shuttles, and spacecraft.

[0087] In some embodiments of this application, the electrical device 400 further includes an energy storage device 300 as described above. That is, the electrical device 400 employs one energy storage device 300 or multiple energy storage devices 300 connected in series, parallel, or in a mixed configuration, and the electrical load 410 is electrically connected to the energy storage device 300. The battery device 200 of the energy storage device 300 is used to store electrical energy, or the battery device 200 of the energy storage device 300 is used to provide electrical energy to the electrical load 410, thereby enabling the electrical load 410 to operate normally.

[0088] Alternatively, in some other embodiments of this application, the electrical device 400 further includes a battery device 200 as described above. That is, the electrical device 400 uses one battery device 200 or multiple battery devices 200 connected in series, parallel, or mixed connection, and the electrical load 410 is electrically connected to the battery device 200. The battery device 200 is used to store electrical energy, or the battery device 200 is used to provide electrical energy to the electrical load 410, thereby enabling the electrical load 410 to operate normally.

[0089] Alternatively, in some other embodiments of this application, the electrical device 400 further includes a plurality of battery cells 100 as described above. That is, the electrical device 400 uses a plurality of battery cells 100 connected in series, parallel, or in a mixed configuration, and the electrical load 410 is electrically connected to the plurality of battery cells 100. The plurality of battery cells 100 are used to store electrical energy, or the plurality of battery cells 100 are used to provide electrical energy to the electrical load 410, thereby enabling the electrical load 410 to operate normally.

[0090] Among them, the electrical equipment 400 is an electric vehicle, and it is assembled using a battery device 200, such as Figure 11 As shown, the battery device 200 is mounted on the frame 430 of the electric vehicle. The electric vehicle includes the frame 430, a drive motor, and wheels 440. The battery device 200 and the drive motor are both fixedly mounted on the frame 430, and the wheels 440 are rotatably connected to the frame 430. The battery device 200 is electrically connected to the drive motor, and the drive motor is driven by the wheels 440. When the battery device 200 provided in this application supplies power to the drive motor (the drive motor is one of the electrical loads 410 of the electrical equipment 400), the drive motor drives the wheels 440 to rotate, enabling the electric vehicle to drive normally. Furthermore, the electric vehicle includes a control device 420, which is mounted on the frame 430 and electrically connected to the battery device 200. The control device 420 is used to control and monitor the charging and discharging status of the battery device 200. In some electric vehicles, the battery housing of the battery device 200 can be part of the chassis structure of the electric vehicle. For example, a portion of the battery box can be at least part of the floor of the electric vehicle, or a portion of the battery box can be at least part of the crossbeams and longitudinal beams of the electric vehicle.

[0091] The above description is merely a preferred embodiment of this application and is not intended to limit this application. 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.

Claims

1. A battery cell, characterized by, The battery cell comprises: a housing having a receiving space; an electrode assembly accommodated in the receiving space; a pressure relief mechanism arranged on a side wall of the housing; a protective layer arranged on the inner side of the side wall of the housing provided with the pressure relief mechanism, in the direction from the electrode assembly to the pressure relief mechanism, the projection of the protective layer covers at least the circumferential edge area of the pressure relief mechanism, the protective layer is provided with an overflow channel, the overflow channel is arranged opposite at least part of the pressure relief area of the pressure relief mechanism, and the protective layer is arranged spaced apart from the electrode assembly.

2. The battery cell according to claim 1, wherein in the direction from the electrode assembly to the pressure relief mechanism, the projection of the protective layer coincides with the projection of the side wall of the housing provided with the pressure relief mechanism.

3. The battery cell according to claim 1, wherein the overflow channel is arranged opposite the pressure relief area of the pressure relief mechanism.

4. The battery cell according to claim 1, wherein the protective layer is a component made of mica material, carbon fiber material, graphite copper material, aerogel material or ceramic plate material.

5. The battery cell according to claim 4, wherein the thickness of the protective layer ranges from 0.5mm to 5.0mm.

6. The battery cell according to claim 1, wherein the protective layer is adhered to the side wall of the housing by structural adhesive.

7. The battery cell according to any one of claims 1-6, wherein the housing comprises a housing body and a housing cover, the housing cover covers the housing body to form the receiving space, the battery cell further comprises a pole structure, the pressure relief mechanism and the pole structure are arranged on the housing cover, and the protective layer is arranged on the inner side of the housing cover.

8. The battery cell according to claim 7, wherein the protective layer is further provided with a through hole, and the tab of the electrode assembly passes through the through hole to electrically connect with the pole structure.

9. The battery cell according to any one of claims 1-6, wherein the housing comprises a housing body and a housing cover, the housing cover covers the housing body to form the receiving space, the battery cell further comprises a pole structure, the pole structure is arranged on the housing cover, the pressure relief mechanism is arranged on the bottom wall of the housing body opposite to the housing cover, and the protective layer is arranged on the inner side of the bottom wall of the housing body.

10. The battery cell according to any one of claims 1-6, wherein the housing comprises a housing body, a first housing cover and a second housing cover, the first housing cover and the second housing cover cover the two ends of the housing body respectively to form the receiving space, the battery cell further comprises a positive pole and a negative pole, the positive pole and the negative pole are arranged on the first housing cover and the second housing cover respectively, the pressure relief mechanism is arranged on one of the side walls of the housing body, and the protective layer is arranged on the inner side of the side wall of the housing body provided with the pressure relief mechanism.

11. A battery device characterized by comprising: The battery cell as claimed in any one of claims 1-10 is used for storing or providing electric energy.

12. An energy storage device, comprising The energy storage device comprises the battery cell according to any one of claims 1-10, and the battery cell is used for storing or providing electric energy. Alternatively, the energy storage device comprises the battery device according to claim 11, and the battery device is used for storing or providing electric energy.

13. An electrical device, characterized by The electric load comprises a plurality of battery cells according to any one of claims 1-10, and the electric load is electrically connected with the plurality of battery cells. Alternatively, the electric load comprises the battery device according to claim 11, and the electric load is electrically connected with the battery device. Alternatively, the electric load comprises the energy storage device according to claim 12, and the electric load is electrically connected with the energy storage device. ​

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