Battery cell, battery device, and electric device

Abstract

The application discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises an electrode assembly and a closed structure. The electrode assembly comprises a plurality of pole pieces. The plurality of pole pieces are stacked along a first direction. In a second direction, the closed structure is arranged on at least one side of the electrode assembly to block a gap between two adjacent pole pieces. The first direction and the second direction are perpendicular to each other. According to the battery monomer, the second direction side of the electrode assembly is blocked by the closed structure, the direction of the thermal runaway heat flow during thermal runaway can be better adjusted, the discharge direction of the thermal runaway jet flow can be better controlled, the thermal runaway jet flow can be discharged from the shell more quickly, the risk of fire and explosion of the battery monomer during thermal runaway can be reduced, and the safety of the battery monomer can be improved.

Description

Technical Field

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

[0002] In recent years, new energy vehicles have experienced rapid development. In the field of electric vehicles, battery devices, as the power source, play an irreplaceable and crucial role. Among these, battery devices, as core components of new energy vehicles, have high requirements in terms of safety.

[0003] For the same capacity, the thermal runaway intensity of laminated cells is generally greater than that of wound cells. This difference is due to the fact that the sides of wound cells are basically closed, while the sides of laminated cells are open. Visual ignition experiments with fully charged bare cells have revealed that during thermal runaway, the thermal runaway jet of wound cells is generally vertical, while the thermal runaway jet of laminated cells is both vertical and horizontal. This makes laminated cells more difficult to control during thermal runaway, resulting in a higher safety hazard and affecting the safety of the battery device. Utility Model Content

[0004] This application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of this application is to provide a battery cell, and a battery device and an electrical device comprising the battery cell, wherein the battery cell can have good safety.

[0005] In a first aspect, embodiments of this application provide a battery cell, comprising: an electrode assembly including a plurality of electrodes stacked along a first direction; and a sealing structure disposed on at least one side of the electrode assembly in a second direction for sealing the gap between two adjacent electrodes, wherein the first direction and the second direction are perpendicular to each other.

[0006] According to the embodiments of this application, the battery cell can effectively adjust the direction of thermal runaway heat flow during thermal runaway by sealing the side of the electrode assembly in the second direction through a closed structure. This allows the discharge direction of the thermal runaway jet to be better controlled, and the thermal runaway jet to be discharged from the casing more quickly. This can effectively reduce the risk of fire and explosion of the battery cell during thermal runaway, thereby improving the safety of the battery cell.

[0007] In some embodiments of this application, the electrode includes a first electrode and a second electrode, wherein the first electrode is a positive electrode and the second electrode is a negative electrode. A plurality of first electrodes and a plurality of second electrodes are arranged alternately along a first direction. In the second direction, the size of the second electrode is larger than the size of the first electrode, so that a gap space is formed between two adjacent second electrodes. At least part of the closed structure fills the gap space to seal the gap space.

[0008] In the above example, by sealing the gap space with a closed structure, when the thermal runaway jet is discharged toward the gap space, the closed structure can effectively restrict the discharge direction of the thermal runaway jet, thereby allowing the thermal runaway jet to be discharged toward a third direction. This adjusts the discharge direction of the thermal runaway jet, making the discharge direction of the thermal runaway jet better controlled, and thus improving the safety of the battery cell.

[0009] In some embodiments of this application, the sealing structure abuts against the first electrode to seal between the first electrode and the second electrode.

[0010] In the above example, when the closed structure is arranged in the gap space, it can effectively seal the space between the first and second electrodes, making it difficult for the thermal runaway jet to enter the gap space and thus preventing leakage through the gap space.

[0011] In some embodiments of this application, the battery cell further includes a separator, wherein in the second direction, the separator includes a first portion and a second portion connected together, the first portion being located between two adjacent electrodes, the second portion being located on both sides of the electrodes in the second direction, and the second portion being enclosed within the closed structure.

[0012] In the above example, by enclosing the second part within a closed structure, the entire side of the electrode assembly is sealed off, thereby effectively limiting the outflow direction of the thermal runaway jet, thus reducing the risk of the battery cell catching fire and exploding under thermal runaway, and improving the safety of the battery cell.

[0013] In some embodiments of this application, in the second direction, the distance between the edge of the diaphragm and the edge of the closed structure is e, which satisfies: 0mm < e ≤ 5mm.

[0014] In the above example, by setting the above dimensions, the sealing effect of the closed structure on the electrode assembly can be improved while not easily affecting the assembly of the electrode assembly.

[0015] In some embodiments of this application, the sealing structure includes a sealant disposed on both sides of the electrode in the second direction; or, the sealing structure includes a plate, a felt, or a woven fabric, which is fixed to both sides of the electrode in the second direction.

[0016] In the above examples, by making the sealing structure include sealant, sheet, felt or woven fabric, the lateral propagation of the electrode assembly during thermal runaway can be effectively suppressed, thereby effectively limiting the outflow direction of the thermal runaway jet, thus effectively reducing the risk of battery cells catching fire and exploding under thermal runaway, and thus improving the safety of battery cells.

[0017] In some embodiments of this application, the sealant is silicone rubber.

[0018] In the above example, by sealing the side of the electrode assembly with silicone rubber, the outflow direction of the thermal runaway jet can be effectively restricted, thereby reducing the risk of fire and explosion of the battery cell under thermal runaway and improving the safety of the battery cell.

[0019] In some embodiments of this application, in the first direction, the electrode assembly has a first surface and a second surface that are opposite to each other, and a portion of the enclosed structure covers the first surface and / or the second surface.

[0020] In the above example, by enabling the enclosed structure to cover the first and second surfaces, it can effectively isolate the electrode assembly from the erosion of impurities such as moisture, oxygen and dust in the external environment. It can also enhance the structural strength of the electrode assembly and reduce the risk of deformation or damage caused by external impact and vibration during assembly and use.

[0021] In some embodiments of this application, the electrode includes a positive electrode and a negative electrode. The positive electrode includes a positive current collector and a positive active material layer disposed on at least one side of the positive current collector. The positive active material layer includes a lithium-containing transition metal oxide. The negative electrode includes a negative current collector and a negative active material layer disposed on at least one side of the negative current collector. The negative active material layer includes a silicon-carbon material.

[0022] In the above example, by including lithium-containing transition metal oxides in the positive electrode active material layer and silicon-carbon materials in the negative electrode active material layer, the energy density of the battery cell can be improved. The sealing component in this embodiment can effectively seal the side of the electrode assembly, thereby adjusting the outflow direction of the thermal runaway jet, which is beneficial to the control of the thermal runaway jet, and can reduce the risk of battery cell fire and explosion due to thermal runaway, thus improving the safety of the battery cell.

[0023] Secondly, embodiments of this application provide a battery device, which includes the battery cells described in the above embodiments.

[0024] In the above example, by incorporating the battery cells described in the above embodiment, the safety of the battery device can be significantly improved.

[0025] Secondly, embodiments of this application provide an electrical device, which includes the battery device described in the above embodiments.

[0026] In the above technical solution, by setting the battery device of the example above, the power device of this application can have better safety.

[0027] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0028] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0029] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0030] Figure 2 This is a schematic diagram of the electrode assembly and enclosed structure of a battery cell according to an embodiment.

[0031] Figure 3 This is a schematic diagram of the electrode assembly of a battery cell according to an embodiment.

[0032] Figure label:

[0033] 1000, Vehicle; 100, Battery unit; 200, Controller; 300, Motor;

[0034] 1. Electrode assembly; 11. First electrode; 12. Second electrode; 13. Diaphragm; 14. Gap space;

[0035] 2. Closed structure;

[0036] 31. Third electrode; 311. First surface; 32. Fourth electrode; 321. Second surface;

[0037] X, the first direction; Y, the second direction. Detailed Implementation

[0038] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0040] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0041] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0042] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0043] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two).

[0044] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0045] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0046] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include one or more battery cells; when there are multiple battery cells, they are connected in series, parallel, or mixed connections via a busbar.

[0047] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0048] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0049] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0050] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0051] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0052] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0053] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0054] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0055] The battery cells mentioned in the embodiments of this application may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited to these. Battery cells may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited to these shapes either. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and the embodiments of this application are not limited to these types either.

[0056] For example, a single battery cell typically includes a housing, a cell assembly, and an electrolyte. The housing is used to house the cell assembly and the electrolyte, and the housing has at least one positive electrode post and at least one negative electrode post. The cell assembly includes one or more electrode assemblies, which are formed by stacking or winding positive electrode sheets, negative electrode sheets, and separators.

[0057] The positive electrode generally includes a positive current collector and a positive active material layer. The positive active material layer is directly or indirectly coated on the positive current collector. The positive current collector without the positive active material layer protrudes from the positive current collector with the positive active material layer. The positive current collector without the positive active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and form an electrical connection with the positive electrode post. For example, the multiple stacked positive electrode tabs can be directly soldered to the positive electrode post to form an electrical connection; or, the battery cell assembly can also include a positive electrode adapter piece. The multiple stacked positive electrode tabs are soldered to one end of the positive electrode adapter piece, and the other end of the positive electrode adapter piece is soldered to the positive electrode post, so that the positive electrode tabs and the positive electrode post form an electrical connection.

[0058] The negative electrode generally includes a negative current collector and a negative active material layer. The negative active material layer is directly or indirectly coated on the negative current collector. The negative current collector without the negative active material layer protrudes from the negative current collector with the negative active material layer. The negative current collector without the negative active material layer serves as a negative electrode tab. Multiple negative electrode tabs are stacked together and form an electrical connection with the negative electrode post. For example, the stacked negative electrode tabs can be directly welded to the negative electrode post to form an electrical connection; alternatively, the battery cell assembly may also include a negative electrode adapter piece. The stacked negative electrode tabs are welded to one end of the negative electrode adapter piece, and the other end of the negative electrode adapter piece is welded to the negative electrode post, so that the negative electrode tabs and the negative electrode post form an electrical connection. The material of the separator is not limited; for example, it can be polypropylene or polyethylene.

[0059] Meanwhile, individual battery cells primarily function by the movement of metal ions between the positive and negative electrode plates. Taking lithium-ion batteries as an example, the positive electrode current collector can be made of aluminum, and the positive electrode active material layer can be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode current collector can be made of copper, and the negative electrode active material layer can be made of carbon or silicon, etc. During charging and discharging, Li+ ions repeatedly insert and extract between the two electrodes: during charging, Li+ ions extract from the positive electrode, pass through the electrolyte, and insert into the negative electrode, leaving the negative electrode in a lithium-rich state; the reverse occurs during discharging.

[0060] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0061] In recent years, new energy vehicles have experienced rapid development. In the field of electric vehicles, battery devices, as the power source, play an irreplaceable and crucial role. Among these, battery devices, as core components of new energy vehicles, have high requirements in terms of safety.

[0062] For the same capacity, the thermal runaway intensity of laminated cells is generally greater than that of wound cells. This difference is due to the fact that the sides of wound cells are basically closed, while the sides of laminated cells are open. Visual ignition experiments with fully charged bare cells have revealed that during thermal runaway, the thermal runaway jet of wound cells is generally vertical, while the thermal runaway jet of laminated cells is both vertical and horizontal. This makes laminated cells more difficult to control during thermal runaway, resulting in a higher safety hazard and affecting the safety of the battery device.

[0063] Based on the above considerations, in order to improve the safety of the battery cell, the applicant has conducted in-depth research and designed a battery cell that can effectively limit the discharge direction of the thermal runaway jet when the electrode assembly is thermally runaway by sealing the side of the electrode assembly. This allows the electrode assembly to be better controlled during thermal runaway, thereby improving the safety of the battery cell.

[0064] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0065] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery cell 20 is disposed inside the vehicle 1000, and the battery cell 20 can be located at the bottom, front, or rear of the vehicle 1000. The battery cell 20 can be used to power the vehicle 1000; for example, the battery cell 20 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery cell 20 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0066] In some embodiments of this application, the battery cell 20 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0067] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the electrode assembly 1 and the enclosure structure 2 of a battery cell according to an embodiment.

[0068] In some embodiments of this application, such as Figure 2 As shown, the battery cell includes an electrode assembly 1 and a sealing structure 2. The electrode assembly 1 includes multiple electrodes stacked along a first direction X and along a second direction Y. The sealing structure 2 is disposed on at least one side of the electrodes to seal the gap between two adjacent electrodes. The first direction X and the second direction Y are perpendicular to each other.

[0069] For example, a battery cell includes a housing, with an electrode assembly 1 and a sealing structure 2 both located inside the housing. The housing includes a cover, which can be located at one end of a third direction. This third direction is perpendicular to the first direction X and the second direction Y, respectively. Thus, for an electrode assembly 1 constructed by stacking multiple electrodes along the first direction X, the electrode assembly 1 is in an open state in both the second direction Y and the third direction. The sealing structure 2 is disposed on the side of the electrode in the second direction Y, thereby effectively sealing the side of the electrode assembly 1 in the second direction Y. When the electrode assembly 1 experiences thermal runaway... The thermal runaway jet is not easily ejected from the side of the blocked second direction Y. That is, the closed structure 2 can restrict the discharge direction of the thermal runaway jet, so that the thermal runaway jet can be discharged in the third direction. The shell cover can be located at one end of the electrode assembly 1 in the third direction. An explosion-proof valve or an exhaust valve can be arranged on the shell cover, so that the discharge direction of the thermal runaway jet can be better controlled. The thermal runaway jet can be discharged from the shell relatively quickly, which can better reduce the risk of fire and explosion of the battery cell during thermal runaway, and thus better improve the safety of the battery cell.

[0070] For example, the closed structure 2 can be arranged on one side of the second direction Y of the electrode, or on both sides of the second direction Y of the electrode, and this application does not limit it.

[0071] For example, in the second direction Y, the sealing structure 2 can completely seal the side of the electrode assembly 1, or the side of the electrode assembly 1 can be in a semi-closed state. That is, the semi-closed state is intended to reduce the thermal runaway jet from the second direction Y, thereby allowing a larger amount of thermal runaway jet to be discharged from the third direction. Furthermore, it should be noted that the sealing area of ​​the side of the electrode assembly 1 by the sealing structure 2 can occupy between 50% and 100% of the area of ​​the side of the electrode assembly 1. Specific percentage examples can be: 60%, 70%, 80%, 85%, 90%, 95%, etc. This application does not limit this.

[0072] In the above example, by sealing the side of the electrode assembly 1 in the second direction Y by the closed structure 2, the direction of thermal runaway heat flow during thermal runaway can be better adjusted, so that the discharge direction of the thermal runaway jet can be better controlled, and the thermal runaway jet can be discharged from the shell more quickly. This can better reduce the risk of fire and explosion of the battery cell during thermal runaway, and thus better improve the safety of the battery cell.

[0073] Please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of the electrode assembly 1 of a battery cell according to an embodiment.

[0074] In some embodiments of this application, such as Figure 2 and Figure 3As shown, the electrode includes a first electrode 11 and a second electrode 12. The first electrode 11 can be a positive electrode, and the second electrode 12 can be a negative electrode. Multiple first electrodes 11 and multiple second electrodes 12 are arranged alternately along a first direction X. In the second direction Y, the size of the second electrode 12 is larger than the size of the first electrode 11, so that a gap space 14 is formed between two adjacent second electrodes 12. At least a portion of the closed structure 2 fills the gap space 14 to seal the gap space 14.

[0075] In other words, the second electrode 12 is larger than the first electrode 11. After the first electrode 11 and the second electrode 12 are stacked along the first direction X, multiple gap spaces 14 can be constructed on the outer periphery of the electrode assembly 1. The multiple gap spaces 14 are spaced apart along the first direction X. At this time, the closed structure 2 can be filled in the gap space 14. Thus, in the first direction X, the two sides of the closed structure 2 can respectively fit with two adjacent second electrodes 12. Therefore, when the thermal runaway jet is discharged toward the gap space 14, the closed structure 2 can better restrict the discharge direction of the thermal runaway jet, so that the thermal runaway jet can be discharged toward a third direction, thereby adjusting the discharge direction of the thermal runaway jet.

[0076] For example, in the second direction Y, the closed structure 2 may not be in contact with the first electrode 11. In this way, a discharge channel can be constructed between the first electrode 11 and the closed structure 2. After entering the discharge channel, the thermal runaway jet can be discharged in a better direction along the discharge channel, thereby improving the discharge efficiency of the thermal runaway jet.

[0077] For example, in the second direction Y, the closed structure 2 can also contact the first electrode 11, thereby increasing the contact area between the closed structure 2 and the electrode assembly 1, which can better improve the connection strength between the closed structure 2 and the electrode assembly 1, making it less likely for the thermal runaway jet to blow the closed structure 2 off the electrode assembly 1, so that the closed structure 2 can be reliably sealed on the side of the electrode assembly 1 in the second direction Y.

[0078] For example, the closed structure 2 may not be exposed from the gap space 14. Thus, multiple closed structures 2 are provided, and multiple closed structures 2 correspond one-to-one with multiple gap spaces 14. When one closed structure 2 fails, it is not easy to affect the adjacent closed structures 2.

[0079] Exemplarily, the closed structure 2 can also be exposed from within the gap space 14. Here, it can be understood that after the electrode assembly 1 is assembled in the housing, the space between the electrode assembly 1 and the wall of the housing is limited. Therefore, when the electrode assembly 1 experiences thermal runaway, the wall of the housing can better support the closed structure 2, making it less likely for the closed structure 2 to be washed away by the thermal runaway jet. In addition, if the closed structure 2 is exposed from within the gap space 14, two adjacent closed structures 2 can be connected into a whole, or even multiple closed structures 2 can form a whole. In other words, the closed structure 2 is a single structure with multiple filling portions extending into the gap space 14. This application does not limit this. Taking the closed structure 2 as a single structure with multiple filling portions extending into the gap space 14 as an example, when configured in this way, the consistency of the closed structure 2 is better, and compared to individual closed structures 2 filling different gap spaces 14, the connection strength between a single closed structure 2 and the electrode assembly 1 is higher, thereby improving the reliability of the closed structure 2.

[0080] In the above example, by sealing the gap space 14 with the closed structure 2, when the thermal runaway jet is discharged toward the gap space 14, the closed structure 2 can effectively restrict the discharge direction of the thermal runaway jet, thereby allowing the thermal runaway jet to be discharged toward a third direction. This adjusts the discharge direction of the thermal runaway jet, making the discharge direction of the thermal runaway jet better controlled, and thus improving the safety of the battery cell.

[0081] In some embodiments of this application, such as Figure 2 As shown, the closed structure 2 abuts against the first electrode 11 to seal between the first electrode 11 and the second electrode 12.

[0082] In other words, when the closed structure 2 is arranged in the gap space 14, it can effectively seal between the first electrode 11 and the second electrode 12, making it difficult for the thermal runaway jet to enter the gap space 14 and thus preventing leakage through the gap space 14. In addition, the contact between the closed structure 2 and the first electrode 11 can increase the contact area between the closed structure 2 and the electrode assembly 1. For example, the closed structure 2 can be fixedly connected to the first electrode 11 after contact, which can effectively increase the fixed connection area and improve the connection strength between the closed structure 2 and the electrode assembly 1, making it difficult for the thermal runaway jet to blow the closed structure 2 off the electrode assembly 1. Thus, the closed structure 2 can be reliably sealed on the side of the electrode assembly 1 in the second direction Y.

[0083] In the above example, when the closed structure 2 is arranged in the gap space 14, it can effectively seal the space between the first electrode 11 and the second electrode 12, making it difficult for the thermal runaway jet to enter the gap space 14 and thus making it difficult for leakage to occur through the gap space 14.

[0084] In some embodiments of this application, such as Figure 2 As shown, the battery cell also includes a separator 13. In the second direction Y, the separator 13 includes a first part and a second part connected together. The first part is located between two adjacent electrodes, and the second part is located on both sides of the electrodes in the second direction Y. The second part is enclosed in the closed structure 2.

[0085] In other words, the diaphragm 13 is relatively large. For example, the diaphragm 13 can wrap around the first electrode 11 or the second electrode 12. Therefore, in the projection plane perpendicular to the first direction X, the diaphragm 13 can have a portion overlapping with the first electrode 11 and the second electrode 12. This portion can be the first part. Furthermore, if the first electrode 11 is a positive electrode and the second electrode 12 is a negative electrode, the projected area of ​​the second electrode 12 is larger than the projected area of ​​the first electrode 11. Therefore, the overlapping projection of the diaphragm 13 and the second electrode 12 is mainly considered as the first part of the diaphragm 13. The portion extending beyond the second electrode 12 in the second direction Y can be considered as the diaphragm. The second part of 13 can be understood as follows: if it is only sealed between two adjacent second electrodes 12, and the second electrodes 12 are provided with a diaphragm 13 on their sides, then the sealing structure 2 is actually sealed between the diaphragms 13. For the time between the second electrodes 12 and the diaphragm 13, or even between the diaphragm 13 and the sealing structure 2, the thermal runaway jet is more likely to flow out from these locations. Therefore, in this example, by making the second part of the diaphragm 13 covered in the sealing structure 2, the entire side of the electrode assembly 1 can be sealed, thereby better limiting the outflow direction of the thermal runaway jet, thereby better reducing the risk of the battery cell catching fire and exploding under thermal runaway.

[0086] In the above example, by enclosing the second part within the closed structure 2, the entire side of the electrode assembly 1 is sealed off, thereby effectively limiting the outflow direction of the thermal runaway jet, thus effectively reducing the risk of the battery cell catching fire and exploding under thermal runaway, and thus improving the safety of the battery cell.

[0087] In some embodiments of this application, in the second direction Y, the distance between the edge of the diaphragm 13 and the edge of the closed structure 2 is e, which satisfies: 0mm < e ≤ 5mm.

[0088] In other words, by setting the above dimensions, the sealing effect of the closed structure 2 on the electrode assembly 1 can be improved while not easily affecting the assembly of the electrode assembly 1.

[0089] For example, the distance e between the edge of the diaphragm 13 and the edge of the closed structure 2 can be 1mm, 1.5mm, 1.6mm, 1.8mm, 2mm, 3mm, 4mm, 5mm, etc., and this application does not limit it.

[0090] In some embodiments of this application, the sealing structure 2 includes a sealant disposed on both sides of the electrode sheet in the second direction Y; or, the sealing structure 2 includes a plate, felt, or woven fabric, which is fixed to both sides of the electrode sheet in the second direction Y.

[0091] For example, the sealing structure 2 includes a sealant that has a certain degree of high-temperature resistance. This prevents the thermal runaway jet from damaging the sides of the casing, reducing the risk of side rupture or even thermal runaway jet ejection from the battery cells. Consequently, structural components located on the sides of the battery cells are well protected. Furthermore, the sealant only needs to be applied by brushing. Its adhesiveness and fluidity allow it to effectively seal the sides of the electrode assembly 1, resulting in high reliability.

[0092] For example, the sealant can be a material that is resistant to electrolyte, insulating, and has good tensile strength. In addition, when the sealant encapsulates the second part of the diaphragm 13, it can also make the first electrode 11, the second electrode 12, and the diaphragm 13 better connected.

[0093] For example, the closed structure 2 includes a plate, felt or woven fabric. The plate, felt or woven fabric can be closely attached to the side of the electrode assembly 1, so that the side of the electrode assembly 1 is in a semi-closed state, which can have a good effect on suppressing the lateral spread of the electrode assembly 1 during thermal runaway.

[0094] In the above example, by making the closed structure 2 include sealant, sheet, felt or woven fabric, the lateral propagation of electrode assembly 1 during thermal runaway can be effectively suppressed, thereby effectively limiting the outflow direction of the thermal runaway jet, thus effectively reducing the risk of battery cell fire and explosion under thermal runaway, and thus improving the safety of battery cell.

[0095] In some embodiments of this application, the sealant is silicone rubber, a high-molecular elastic material with silicon-oxygen bonds as the main chain. It has excellent high and low temperature resistance (it can maintain elasticity in a range of -60°C to 200°C or even wider), and also has excellent aging resistance, ozone resistance and chemical stability. It is not easily corroded by ultraviolet rays, oxygen and various chemicals. It has excellent electrical insulation properties and good flexibility, air permeability and biocompatibility. Therefore, silicone rubber can effectively seal the side of the electrode assembly 1, thereby effectively limiting the discharge direction of the thermal runaway jet.

[0096] Furthermore, silicone rubber is a synthetic rubber that can be cured in situ. "In-situ curing" refers to the process where silicone rubber material does not need to be pre-formed in an external mold or specific container, but instead undergoes a curing reaction directly at its final application location or interface, transforming from a liquid state (or uncured state such as paste or slurry) into a solid elastomer. Simply put, silicone rubber can be applied, injected, or filled directly into the gaps, surfaces, or specific spaces of the target component, just like "on-site casting," completing the transformation from a flowable state to a fixed form in situ. Ultimately, it forms a tightly bonded whole with the contacting substrate or structure. Therefore, by sealing the side of electrode assembly 1 with silicone rubber, the outflow direction of the thermal runaway jet can be effectively restricted, thereby reducing the risk of fire and explosion of the battery cell under thermal runaway, and thus improving the safety of the battery cell.

[0097] In some embodiments of this application, such as Figure 2 and Figure 3 As shown, in the first direction X, the electrode assembly 1 has a first surface 311 and a second surface 321 that are opposite to each other, and a portion of the enclosed structure 2 covers the first surface 311 and / or the second surface 321.

[0098] In other words, by allowing the sealing structure 2 to cover the first surface 311 and the second surface 321, it can effectively isolate impurities such as moisture, oxygen, and dust from the external environment. This prevents these substances from entering from the sides of the electrode assembly 1 and coming into contact with the electrode, thus avoiding chemical reactions or physical contamination. It also reduces the performance degradation of the electrode due to corrosion and oxidation, and effectively protects vulnerable areas such as the edges of the electrode. In addition, the sealing structure 2 covering the first surface 311 and the second surface 321 also enhances the structural strength of the electrode assembly 1, reducing the risk of deformation or damage caused by external impacts and vibrations during assembly and use.

[0099] For example, among the multiple electrodes, the two electrodes located on both sides are the third electrode 31 and the fourth electrode 32, respectively. The surface of the third electrode 31 facing away from the fourth electrode 32 is the first surface 311, and the surface of the fourth electrode 32 facing away from the third electrode 31 is the second surface 321. Part of the closed structure 2 covers the first surface 311 and / or the second surface 321.

[0100] In the above example, by enabling the closed structure 2 to cover the first surface 311 and the second surface 321, it can effectively isolate the electrode assembly 1 from the erosion of impurities such as moisture, oxygen and dust in the external environment. It can also enhance the structural strength of the electrode assembly 1 and reduce the risk of deformation or damage to the electrode assembly 1 caused by external impact and vibration during assembly and use.

[0101] In some embodiments of this application, such as Figure 2 and Figure 3 As shown, the electrode includes a positive electrode and a negative electrode. The positive electrode includes a positive current collector and a positive active material layer disposed on at least one side of the positive current collector. The positive active material layer includes a lithium-containing transition metal oxide. The negative electrode includes a negative current collector and a negative active material layer disposed on at least one side of the negative current collector. The negative active material layer includes a silicon-carbon material.

[0102] For example, lithium-containing transition metal oxides may include LiNixCoyMnzO2 (NCM) and LiNixCoyAlzO2 (NCA), both of which have high energy densities, enabling batteries to store more energy. Simultaneously, they possess a high voltage platform, allowing the battery to operate at higher voltages, further improving energy and power densities. LiNixCoyMnzO2 (NCM) and LiNixCoyAlzO2 (NCA) also contain nickel; the high electrochemical activity of nickel can effectively improve the specific capacity of the positive electrode and enhance the electronic conductivity of the material, allowing the positive electrode to better achieve lithium-ion insertion and extraction during charging and discharging.

[0103] The negative electrode active material layer includes silicon-carbon materials. Silicon has a high theoretical lithium storage capacity (approximately 4200 mAh / g), while the introduction of carbon effectively alleviates the volume expansion problem of silicon during lithium intercalation, improving the structural stability and cycle performance of the negative electrode. This silicon-carbon composite system can effectively improve the specific capacity of the negative electrode, forming a capacity match with the high-nickel positive electrode, thereby improving the energy density of electrode assembly 1 and ultimately increasing the energy density of the battery cell.

[0104] For the high-energy-density electrode assembly 1 and the battery cell, by providing the sealing element of the present application embodiment, the side of the electrode assembly 1 can be effectively sealed, thereby adjusting the outflow direction of the thermal runaway jet, which is beneficial to the control of the thermal runaway jet, thereby reducing the risk of the battery cell catching fire and exploding due to thermal runaway, and improving the safety of the battery cell.

[0105] In the above example, by including lithium-containing transition metal oxides in the positive electrode active material layer and silicon-carbon materials in the negative electrode active material layer, the energy density of the battery cell can be improved. The sealing component in this embodiment can effectively seal the side of the electrode assembly 1, thereby adjusting the outflow direction of the thermal runaway jet, which is beneficial to the control of the thermal runaway jet, and can reduce the risk of the battery cell catching fire and exploding due to thermal runaway, thus improving the safety of the battery cell.

[0106] This application also proposes a battery device.

[0107] According to the battery device of the present application, the battery device may include the battery cells of the above embodiments.

[0108] In the above example, by incorporating the battery cells described in the above embodiment, the safety of the battery device can be significantly improved.

[0109] This application also proposes an electrical device.

[0110] According to embodiments of this application, the electrical device may include a battery device for storing or providing electrical energy.

[0111] In the above technical solution, by setting the battery device of the example above, the power device of this application can have better safety.

[0112] Other configurations and operations of the battery cells, battery devices, and electrical devices according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0113] In the description of this specification, references to terms such as "some embodiments," "optionally," "furthermore," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0114] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that, include: An electrode assembly (1) includes a plurality of electrodes stacked along a first direction (X); A closed structure (2) is disposed on at least one side of the electrode assembly (1) in the second direction (Y) for sealing the gap between two adjacent electrodes, wherein the first direction (X) and the second direction (Y) are perpendicular to each other.

2. The battery cell according to claim 1, characterized in that, The electrode includes a first electrode (11) and a second electrode (12), wherein the first electrode (11) is a positive electrode and the second electrode (12) is a negative electrode. A plurality of first electrodes (11) and a plurality of second electrodes (12) are arranged alternately along the first direction (X). In the second direction (Y), the size of the second electrode (12) is larger than the size of the first electrode (11) so that a gap space (14) is formed between two adjacent second electrodes (12). At least a portion of the closed structure (2) fills the gap space (14) to seal the gap space (14).

3. The battery cell according to claim 2, characterized in that, The closed structure (2) abuts against the first electrode (11) to seal between the first electrode (11) and the second electrode (12).

4. The battery cell according to claim 1, characterized in that, Also includes: The diaphragm (13) in the second direction (Y) includes a first part and a second part connected together, the first part being located between the two adjacent electrodes, the second part being located on both sides of the electrodes in the second direction (Y), and the second part being enclosed within the closed structure (2).

5. The battery cell according to claim 4, characterized in that, In the second direction (Y), the distance between the edge of the diaphragm (13) and the edge of the closed structure (2) is e, which satisfies: 0mm < e ≤ 5mm.

6. The battery cell according to claim 1, characterized in that, The sealing structure (2) includes a sealant disposed on both sides of the electrode in the second direction (Y), or, The closed structure (2) includes a plate, a felt or a woven fabric, and the plate, the felt or the woven fabric is fixed on both sides of the electrode in the second direction (Y).

7. The battery cell according to claim 6, characterized in that, The sealant is silicone rubber.

8. The battery cell according to claim 1, characterized in that, In the first direction (X), the electrode assembly (1) has a first surface (311) and a second surface (321) that are opposite to each other, and a portion of the enclosed structure (2) covers the first surface (311) and / or the second surface (321).

9. The battery cell according to claim 1, characterized in that, The electrode includes a positive electrode and a negative electrode. The positive electrode includes a positive current collector and a positive active material layer disposed on at least one side of the positive current collector. The positive active material layer includes a lithium-containing transition metal oxide. The negative electrode includes a negative current collector and a negative active material layer disposed on at least one side of the negative current collector. The negative active material layer includes a silicon-carbon material.

10. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-9.

11. An electrical appliance, characterized in that, Includes the battery device as described in claim 10.

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