Battery cell, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device, the battery monomer comprises a winding type battery cell, the winding type battery cell comprises a pole piece and a diaphragm, the pole piece and the diaphragm are wound for multiple layers along the winding direction to form the winding type battery cell, a coating is arranged between the pole piece and the diaphragm, and the coating is arranged between the pole piece and the diaphragm in the direction from the inner layer to the outer layer. The coating comprises an inner-layer coating, a middle-layer coating and an outer-layer coating, and the particle size R1 of at least part of the middle-layer coating is more than or equal to 5 microns and less than or equal to 50 microns. The battery monomer provided by the utility model can prevent the middle part of the pole piece from being broken in the circulation process, can also be beneficial to electrolyte infiltration, and can reduce the risk that the service life is quickly reduced due to insufficient electrolyte infiltration.

Description

Technical Field

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

[0002] Electric vehicles have become an important part of the sustainable development of the automotive industry due to their energy-saving and environmentally friendly advantages. For electric vehicles, battery technology is a crucial factor in their development. Batteries typically consist of a casing and wound cells housed within the casing. Wound cells are manufactured by winding stacked positive electrode sheets, separators, and negative electrode sheets together and then hot-pressing them.

[0003] However, the innermost and outermost coils of a wound cell have a certain expansion space and are subjected to relatively less force during cycling. The middle part between the innermost and outermost coils is prone to forming a closed area during cycling or after compression, preventing electrolyte from entering and thus easily leading to a rapid decline in cell life. 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 that can prevent the middle electrode from breaking during cycling and can also facilitate electrolyte wetting, thereby reducing the risk of rapid life decay due to insufficient electrolyte wetting.

[0005] This application also proposes a battery device.

[0006] This application also proposes an electrical device.

[0007] According to a first aspect embodiment of the present application, the battery cell includes a wound cell comprising an electrode and a separator, wherein the electrode and the separator are wound in multiple layers along a winding direction to form the wound cell, and a coating is disposed between the electrode and the separator. In the direction from the inner layer to the outer layer, the coating includes an inner coating, a middle coating and an outer coating, wherein at least a portion of the particle size R1 of the middle coating satisfies: 5μm≤R1≤50μm.

[0008] In the above example, by ensuring that the particle size of the intermediate coating meets the aforementioned conditions, after the winding and hot-pressing of the wound cell is completed, the intermediate coating can provide a larger gap in the middle part of the wound cell. This firstly provides a larger expansion space for the middle part of the wound cell, preventing the middle electrode from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the wound cell's cycling.

[0009] In one embodiment of this application, the particle size R2 of the inner coating and the particle size R3 of the outer coating satisfy: R2 < R1, and / or, R3 < R1.

[0010] In the above example, by making the particle size of the inner or outer coating smaller, the inner and outer coatings can provide a denser layer, which helps to improve the insulation effect of the wound cell. In addition, it also allows the electrolyte to be better wetted in the inner and outer coatings of the wound cell.

[0011] In one embodiment of this application, the particle size R2 of the inner coating and the particle size R3 of the outer coating satisfy: 0.1μm≤R2<5μm, and / or, 0.1μm≤R3<5μm.

[0012] In the above example, by making the particle size of the inner coating or the outer coating meet the above conditions, the inner coating and the outer coating can be made more dense, which helps to improve the insulation effect of the wound cell. In addition, it also allows the electrolyte to be better wetted in the inner coating and the outer coating of the wound cell.

[0013] In one embodiment of this application, the particle size of the inner coating is R2, and the particle size of the outer coating is R3, satisfying: 5μm≤R2<50μm, and / or, 5μm≤R3<50μm.

[0014] In the above example, by ensuring that the inner or outer coating meets the aforementioned conditions, the inner and outer coatings can provide a larger gap for the wound cell after the winding and hot-pressing of the wound cell. This firstly provides a larger expansion space for the wound cell, preventing the electrode from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the wound cell's cycling.

[0015] In one embodiment of this application, the wound cell includes a flat region and bent regions located at opposite ends of the flat region, wherein at least a portion of the particle size R1 of the middle coating located in the flat region satisfies: 5μm≤R1≤50μm.

[0016] In the above example, by ensuring that the particle size of the intermediate coating wound in the flat area meets the above conditions, after the winding and hot pressing of the wound cell is completed, the intermediate coating can provide a larger gap in the middle part of the wound cell. This firstly provides a larger expansion space for the middle part of the wound cell, preventing the middle electrode from breaking during cycling. Secondly, the larger gap can also facilitate electrolyte wetting, thus reducing the risk of rapid life decay due to insufficient electrolyte wetting in the later stages of the wound cell's cycling.

[0017] In one embodiment of this application, the particle size R2 of the inner coating layer and the particle size R3 of the outer coating layer located in the flat region satisfy: R2 < R1, and / or, R3 < R1.

[0018] In the above example, by ensuring that the inner or outer coating meets the aforementioned conditions, the inner and outer coatings can provide a larger gap for the wound cell after the winding and hot-pressing of the wound cell. This firstly provides a larger expansion space for the wound cell, preventing the electrode from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the wound cell's cycling.

[0019] In one embodiment of this application, the particle size R2 of the inner coating layer and the particle size R3 of the outer coating layer located in the flat region satisfy: 0.1μm≤R2<5μm, and / or, 0.1μm≤R3<5μm.

[0020] In the above example, by making the particle size of the inner coating or the outer coating meet the above conditions, the inner coating and the outer coating can be made more dense, which helps to improve the insulation effect of the wound cell. In addition, it also allows the electrolyte to be better wetted in the inner coating and the outer coating of the wound cell.

[0021] In one embodiment of this application, the particle size of the inner coating located in the flat region is R2, and the particle size of the outer coating is R3, satisfying: 5μm≤R2<50μm, and / or, 5μm≤R3<50μm.

[0022] In the above example, by ensuring that the inner or outer coating meets the aforementioned conditions, the inner and outer coatings can provide a larger gap for the wound cell after the winding and hot-pressing of the wound cell. This firstly provides a larger expansion space for the wound cell, preventing the electrode from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the wound cell's cycling.

[0023] In one embodiment of this application, at least a portion of the particle size R1 of the intermediate coating located in the bending region satisfies: 5μm≤R1≤50μm.

[0024] In the above example, by ensuring that the particle size of the intermediate coating wound in the bending area meets the above conditions, after the winding and hot pressing of the wound cell is completed, the intermediate coating can provide a larger gap in the middle part of the wound cell. This firstly provides a larger expansion space for the middle part of the wound cell, preventing the middle electrode from breaking during cycling. Secondly, the larger gap can also facilitate electrolyte wetting, thus reducing the risk of rapid life decay due to insufficient electrolyte wetting in the later stages of the wound cell's cycling.

[0025] In one embodiment of this application, the particle size R2 of the inner coating layer and the particle size R3 of the outer coating layer located in the bending region satisfy: R2 < R1, and / or, R3 < R1.

[0026] In the above example, by ensuring that the inner or outer coating meets the aforementioned conditions, the inner and outer coatings can provide a larger gap for the wound cell after the winding and hot-pressing of the wound cell. This firstly provides a larger expansion space for the wound cell, preventing the electrode from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the wound cell's cycling.

[0027] In one embodiment of this application, the particle size R2 of the inner coating layer and the particle size R3 of the outer coating layer located in the bending region satisfy: 0.1μm≤R2<5μm, and / or, 0.1μm≤R3<5μm.

[0028] In the above example, by making the particle size of the inner coating or the outer coating meet the above conditions, the inner coating and the outer coating can be made more dense, which helps to improve the insulation effect of the wound cell. In addition, it also allows the electrolyte to be better wetted in the inner coating and the outer coating of the wound cell.

[0029] In one embodiment of this application, the particle size of the inner coating located in the bending region is R2, and the particle size of the outer coating is R3, satisfying: 5μm≤R2<50μm, and / or, 5μm≤R3<50μm.

[0030] In the above example, by ensuring that the inner or outer coating meets the aforementioned conditions, the inner and outer coatings can provide a larger gap for the wound cell after the winding and hot-pressing of the wound cell. This firstly provides a larger expansion space for the wound cell, preventing the electrode from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the wound cell's cycling.

[0031] In one embodiment of this application, in the direction from the inner layer to the outer layer of the wound cell, there is at least one middle layer coating between the inner layer coating and the outer layer coating.

[0032] In the above example, by arranging the number of intermediate coating layers, a larger gap is provided in the middle part of the wound cell (i.e., the electrode, separator, and the intermediate coating layer itself at the intermediate coating layer position). This firstly provides a larger expansion space for the intermediate coating layer of the wound cell, and the more intermediate coating layers there are, the larger the expansion space, which can prevent the electrode from breaking at the intermediate coating layer during cycling. Secondly, the larger gap can also facilitate the wetting of the electrolyte at the intermediate coating layer. In this way, in the later stages of the winding cell cycling, the electrolyte can better wet the intermediate coating layer, which can reduce the risk of rapid life decay of the intermediate coating layer due to insufficient electrolyte wetting.

[0033] In one embodiment of this application, the coating is disposed on at least one of the diaphragm and the electrode.

[0034] In the above example, the coating application positions can be flexibly arranged according to the actual production and performance requirements of the wound battery cell, thereby improving the flexibility and practicality of the wound battery cell.

[0035] In one embodiment of this application, in the winding direction, the coating includes a first coating segment and a second coating segment, the particle size of the first coating segment is smaller than the particle size of the second coating segment, the middle coating is located in the second coating segment, and the inner coating or the outer coating is located in the first coating segment.

[0036] In the above example, by making the coating have both a first coating segment with a relatively small particle size and a second coating segment with a relatively large particle size, the first coating segment enables the wound battery cell to have good insulation after winding and hot pressing, and the second coating segment enables the wound battery cell to have good electrolyte wetting effect and large expansion space, thereby improving the performance of the wound battery cell.

[0037] In one embodiment of this application, the coating further includes a third coating segment connected to one end of the second coating segment away from the first coating segment, the third coating segment being wound around the inner layer of the second coating segment, the particle size of the third coating segment being smaller than the particle size of the second coating segment, and one of the inner coating and the outer coating being located in the first coating segment and the other being located in the third coating segment.

[0038] In the example above, the third coating segment is wound inside the second coating segment. That is, after the wound cell is wound, the coatings on the inner and outer sides have smaller particle sizes than the coatings in the middle layer, which can provide better insulation for the wound cell. The second coating segment in the middle layer has larger particle sizes, which can provide more expansion space and better electrolyte wetting effect for the wound cell. This allows the wound cell to have good insulation effect, is less prone to electrode breakage during cycling, and extends the service life of the wound cell.

[0039] In one embodiment of this application, the weight of the second coating segment is greater than or equal to the weight of the first coating segment.

[0040] In the above example, by making the weight of the second coating segment greater than or equal to the weight of the first coating segment, and with the particle size of the second coating segment being larger than that of the first coating segment, the second coating segment is designed to be thicker or longer. In this way, after the wound cell is wound, the second coating segment will have a larger expansion space. On the one hand, this can provide stronger support for the wound cell and reduce the risk that the insulation performance of the wound cell will be affected by the larger particle size at the second coating segment. On the other hand, after the wound cell is wound and hot-pressed, the second coating segment can still have a large gap, which is conducive to electrolyte wetting and can reduce the risk of rapid life decay due to insufficient electrolyte wetting.

[0041] In one embodiment of this application, the weight of the second coating segment is greater than or equal to the sum of the weights of the first coating segment and the third coating segment.

[0042] In the above example, by making the weight of the second coating segment greater than or equal to the sum of the weights of the first and third coating segments, and with the particle size of the second coating segment being larger than that of the first coating segment, the second coating segment is designed to be thicker or longer. In this way, after the wound cell is wound, the second coating segment will have a larger expansion space. On the one hand, this can provide stronger support for the wound cell and reduce the risk that the insulation performance of the wound cell will be affected by the larger particle size at the second coating segment. On the other hand, after the wound cell is wound and hot-pressed, the second coating segment can still have a large gap, which is conducive to the wetting of the electrolyte and can reduce the risk of rapid life decay due to insufficient electrolyte wetting.

[0043] In one embodiment of this application, in the winding direction, the length of the coating is L, and the length of the second coating segment is L1, satisfying: 5% ≤ L1 / L ≤ 50%.

[0044] In the above example, by satisfying the above conditions, the second coating segment can form a larger gap inside the wound cell, which is beneficial for the wound cell to expand during cycling and also beneficial for electrolyte wetting.

[0045] In one embodiment of this application, the coating is applied to the diaphragm, and in the winding direction, the length of the coating is less than the length of the diaphragm, and the length of the coating toward the first electrode is greater than or equal to the length of the first electrode; the length of the coating toward the second electrode is greater than or equal to the length of the second electrode.

[0046] In the above example, this difference makes the compact structure of the wound cell possible. On the one hand, the coating length facing the first electrode is greater than or equal to the length of the first electrode, which ensures that the first electrode is effectively insulated and protected, preventing unnecessary electrical contact between the electrode and other components, and ensuring the safety and stability of the battery. Similarly, the coating length facing the second electrode is greater than or equal to the length of the second electrode, which serves the same purpose. Overall, this coating design can optimize the electric field distribution inside the wound cell, reduce the risk of leakage, and at the same time, accurately insulate and protect the electrodes without affecting the basic function of the separator, improving battery performance and reducing the probability of short circuits and other faults, which is of great significance in improving battery reliability.

[0047] This application also proposes a battery device having the battery cells described in the above embodiments.

[0048] In one embodiment of this application, the battery device includes a housing and a battery cell. There is at least one battery cell, which is installed inside the housing. The battery cell includes a casing and a wound cell, with the wound cell located inside the casing.

[0049] In the above example, the battery cell includes a wound cell. From a structural stability perspective, the wound cell has a larger gap in the middle section due to the second coating, which helps maintain the structural integrity of the entire battery device during operation. The electrode in the middle section of the cell is less prone to breakage during cycling, allowing the cell inside the battery device to maintain a stable physical structure and avoiding localized failures caused by electrode breakage, thereby reducing the risk of short circuits or open circuits inside the battery device.

[0050] This application also proposes an electrical device having the battery device described in the above embodiments.

[0051] According to embodiments of this application, the electrical device may include a battery device for storing or providing electrical energy.

[0052] In the above examples, by providing the battery device described above, the power supply device of this application can have higher performance and a longer service life.

[0053] 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

[0054] 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:

[0055] Figure 1 This is a structural schematic diagram of a vehicle according to one embodiment.

[0056] Figure 2 This is an exploded structural diagram of a battery according to one embodiment.

[0057] Figure 3 This is an exploded structural diagram of a battery cell according to one embodiment.

[0058] Figure 4 This is a cross-sectional view of the first electrode, separator, and second electrode of a wound battery cell according to an embodiment after being wound and hot-pressed.

[0059] Figure 5 for Figure 4 The diagram shows region B, where the coating is applied to both sides of the diaphragm.

[0060] Figure 6 for Figure 4 The diagram shows region B, where the coating is applied to both sides of the electrode.

[0061] Figure 7 This is a schematic diagram showing the particle size of the first coating segment, the second coating segment, and the third coating segment coated on both sides of the electrode in an unfolded state according to an embodiment.

[0062] A schematic diagram of the first flat region of a wound battery cell according to an embodiment.

[0063] Figure label:

[0064] 1000, Vehicle; 100, Battery unit; 200, Controller; 300, Motor;

[0065] 10. Box; 11. First box; 12. Second box;

[0066] 20. Battery cell; 21. Top cover; 22. Casing;

[0067] 3. Winded cell; 30. Electrode; 31. First electrode; 32. Second electrode; 33. Separator; 34. Flat region; 341. First flat region; 342. Second flat region; 35. Bending region; 351. First bending region; 352. Second bending region; 36. Coating; 361. Inner coating; 362. Middle coating; 363. Outer coating;

[0068] 41. First coating section; 42. Second coating section; 43. Third coating section. Detailed Implementation

[0069] 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 are only used to explain this application, and should not be construed as limiting this application.

[0070] In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "left," and "right," 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. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" 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.

[0071] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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.

[0072] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0073] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0074] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0075] In related technologies, a battery cell includes a casing and a wound cell. The wound cell is made by stacking positive electrode, separator and negative electrode and then winding and hot pressing them together. The electrode in the middle of the wound cell is straight, and the electrode at the end of the wound cell is arc-shaped. This end is also called the corner of the wound cell. The arc-shaped area on the electrode sheet is called the corner of the electrode sheet; the outermost electrode sheet of a wound cell refers to the outermost ring of negative electrode sheet wound around the wound cell. This ring of negative electrode sheet includes a straight section and a corner section. The straight section is located in the middle of the wound cell, and the corner section is located at the end of the wound cell; the connection between the corner section and the straight section is called the corner connection. During battery cycling, the temperature inside the battery changes. On the one hand, temperature changes cause the electrode sheets inside the wound cell to expand and contract. On the other hand, lithium delithiation and lithium intercalation occur during charging and discharging, which also causes the electrode sheets to expand and contract. The expansion and contraction of the electrode sheets will lead to… The wound battery cell expands and contracts in both width and thickness directions. As the number of cycles increases, the negative electrode rebounds more, and by-reaction products accumulate, leading to a thickening of the negative electrode and irreversible expansion. This causes the wound battery cell to expand irreversibly in both width and thickness directions. However, the innermost and outermost coils of the wound battery cell have a certain expansion space and are subjected to relatively less force during cycling. The middle part between the innermost and outermost coils, especially the straight section, is prone to forming a closed area during cycling or after compression due to thermal pressure. Electrolyte cannot enter, which can easily lead to a rapid decline in the battery cell's lifespan.

[0076] To alleviate the above problems, by ensuring that the particle size of the intermediate coating 362 meets the aforementioned conditions, after the winding and hot-pressing of the wound cell 3 is completed, the intermediate coating 362 can provide a larger gap in the middle part of the wound cell 3. This firstly provides a larger expansion space for the middle part of the wound cell 3, preventing the middle electrode from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the cycle of the wound cell 3.

[0077] In this embodiment of the application, the battery cell 20 can be a secondary battery, which refers to a battery cell 20 that can be used again after being discharged by recharging to activate the active materials.

[0078] The battery cell 20 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, etc., and the embodiments of this application are not limited to this.

[0079] This application provides an electrical device that uses a single battery cell 20 as a power source. The electrical device can be, but is not limited to, a mobile phone, tablet, laptop, electric toy, power tool, electric vehicle, electric car, ship, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells 20, which are connected in series, parallel, or mixed connections via busbars.

[0084] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells 20.

[0085] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells 20 together. As an example, a battery module can also be formed by bundling multiple battery cells 20 together with cable ties.

[0086] In some embodiments, the battery device 100 may be a battery pack, which includes a housing 10 and one or more individual battery cells housed within the housing 10.

[0087] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing 10 by fixing the battery module in the housing 10.

[0088] As an example, the battery cell assembly can also be housed in the housing 10 by directly fixing multiple battery cells 20 to the housing 10.

[0089] As an example, the housing 10 may include a first housing 11 and a second housing 12. The first housing 11 and the second housing 12 are fastened together to form a closed space inside the housing 10 to house the battery cell assembly. Here, "closed" refers to covering or closing, which can be sealed or unsealed. The first housing 11 may be a top cover 21 or a bottom plate.

[0090] As an example, the housing 10 may include a top cover 21, a frame, and a bottom plate. The top cover 21 and the bottom plate are respectively connected to the frame, so that the interior of the housing 10 forms an enclosed space to accommodate the battery cell assembly.

[0091] In some embodiments, the housing 10 may be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 may be at least a portion of the floor of the vehicle 1000, or a portion of the housing 10 may be at least a portion of the crossbeams and longitudinal beams of the vehicle 1000.

[0092] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells 20, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles 1000, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0093] Please refer to Figure 3 , Figure 3This is an exploded structural diagram of a battery cell 20 provided in some embodiments of this application. The battery cell 20 refers to the smallest unit constituting the battery device 100. The battery cell 20 includes a housing 22 and a wound cell 3.

[0094] For example, such as Figure 3 The battery cell 20 includes a top cover 21, a casing 22, a wound cell 3, and other functional components.

[0095] The housing 22 is an assembly used to cooperate with the top cover 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the wound cell 3, electrolyte and other components.

[0096] The wound cell 3 is the component in the battery cell 20 where the electrochemical reaction takes place. The casing 22 may contain one or more wound cells 3. The wound cell 3 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator 33 is usually provided between the positive and negative electrode sheets.

[0097] Combination Figure 4 As shown, Figure 4 This is a cross-sectional view of the positive electrode, separator 33, and negative electrode of a wound battery cell 3 according to an embodiment, after being wound and hot-pressed. Because the coating 36 is very thin, therefore... Figure 4 Coating 36 is not shown in the image.

[0098] Combination Figure 5 As shown, Figure 5 for Figure 4 A schematic diagram of region B, where coating 36 is applied to both sides of diaphragm 33.

[0099] Combination Figure 6 As shown, Figure 6 for Figure 4 A schematic diagram of region B, where coating 36 is applied to both sides of electrode 30.

[0100] In one embodiment of this application, a wound battery cell 3 is provided. The wound battery cell 3 includes an electrode 30 and a separator 33. The electrode 30 and the separator 33 are wound in multiple layers along the winding direction to form the wound battery cell 3. A coating 36 is disposed between the electrode 30 and the separator 33. In the direction from the inner layer to the outer layer, the coating 36 includes an inner coating 361, a middle coating 362 and an outer coating 363. The particle size R1 of at least a portion of the middle coating 362 satisfies: 5μm≤R1≤50μm.

[0101] For example, the wound battery cell 3 includes a first electrode 31, a second electrode 32, and a separator 33 located between the first electrode 31 and the second electrode 32. The first electrode 31, the second electrode 32, and the separator 33 are wound together in a winding direction to form the wound battery cell 3. A coating 36 is provided between the first electrode 31 and the second electrode 32 and the separator 33.

[0102] During the winding process of the wound cell 3, the middle part (i.e., the electrode 30, separator 33, and the middle coating 362 itself at the position of the middle coating 362) may undergo more compression and deformation. By ensuring that the particle size of the middle coating 362 meets the above conditions, the middle coating 362 can have better mechanical strength, which helps to reduce the risk of damage to the middle coating 362 during manufacturing. In addition, the battery will generate heat during use, especially under conditions of rapid charging and discharging or high ambient temperature. Since the middle part is closer to the center of the wound cell 3, it may experience higher temperatures. By ensuring that the particle size of the middle coating 362 meets the above conditions, the middle coating 362 can have better stability and can withstand high temperatures better.

[0103] Finally, the particle size R1 of the intermediate coating 362 satisfies: 5μm≤R1≤50μm. After the winding and hot pressing of the wound cell 3 is completed, the intermediate coating 362 can provide a larger gap in the middle part of the wound cell 3. In this way, firstly, it can provide a larger expansion space in the middle part of the wound cell 3, preventing the middle electrode 30 from breaking during cycling. Secondly, the larger gap can also facilitate the wetting of the electrolyte. In this way, in the later stage of the cycle of the wound cell 3, the risk of rapid life decay due to insufficient electrolyte wetting can be reduced.

[0104] For example, the particle size R1 of the intermediate coating 362 can be 20 μm, 21 μm, 22 μm, 25 μm, 28 μm, 30 μm, 35 μm, 39 μm, 40 μm, 42 μm, 45 μm, 48 μm, or 50 μm. This example is merely illustrative and does not limit the particle size of the intermediate coating 362 of this application.

[0105] In the above example, by ensuring that the particle size of the intermediate coating 362 meets the above conditions, after the winding and hot pressing of the wound cell 3 is completed, the intermediate coating 362 can provide a larger gap in the middle part of the wound cell 3. This firstly provides a larger expansion space for the middle part of the wound cell 3, preventing the middle electrode 30 from breaking during cycling. Secondly, the larger gap can also facilitate the wetting of the electrolyte. Thus, in the later stages of cycling of the wound cell 3, the risk of rapid life decay due to insufficient electrolyte wetting can be reduced.

[0106] In one embodiment of this application, the particle size R2 of the inner coating 361 and the particle size R3 of the outer coating 363 satisfy: R2 < R1, and / or, R3 < R1.

[0107] For example, the particle size of the inner coating 361 is smaller than that of the middle coating 362;

[0108] For example, the particle size of the outer coating 363 is smaller than that of the middle coating 362.

[0109] For example, the particle size of the inner coating 361 and the outer coating 363 are both smaller than the particle size of the middle coating 362.

[0110] In the above example, by making the particle size of the inner coating 361 or the outer coating 363 smaller, the inner coating 361 and the outer coating 363 can provide a denser layer, which helps to improve the insulation effect of the wound cell 3. In addition, it also allows the electrolyte to be better wetted in the inner coating 361 and the outer coating 363 of the wound cell 3.

[0111] In one embodiment of this application, the particle size R2 of the inner coating 361 and the particle size R3 of the outer coating 363 satisfy: 0.1μm≤R2<5μm, and / or, 0.1μm≤R3<5μm.

[0112] For example, the particle size R2 of the inner coating 361 satisfies: 0.1 μm ≤ R2 < 5 μm. For instance, the particle size R2 of the inner coating 361 can be 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 1 μm, 1.1 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2 μm.

[0113] For example, the particle size R3 of the outer coating 363 satisfies: 0.1 μm ≤ R3 < 5 μm. For instance, the particle size R3 of the outer coating 363 can be 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 1 μm, 1.1 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2 μm.

[0114] For example, the particle size R2 of the inner coating 361 satisfies: 0.1μm≤R2<5μm, and the particle size R3 of the outer coating 363 satisfies: 0.1μm≤R3<5μm.

[0115] In the above example, by making the particle size of the inner coating 361 or the outer coating 363 meet the above conditions, the inner coating 361 and the outer coating 363 can be made more dense, which helps to improve the insulation effect of the wound cell 3. In addition, the electrolyte can be better wetted in the inner coating 361 and the outer coating 363 of the wound cell 3.

[0116] In one embodiment of this application, the particle size of the inner coating 361 is R2, and the particle size of the outer coating 363 is R3.

[0117] For example, the particle size of the inner coating 361 is R2, which satisfies: 5μm≤R2≤50μm.

[0118] For example, the particle size of the outer coating 363 is R3, which satisfies: 5μm≤R3≤50μm.

[0119] For example, the particle size of the inner coating 361 and the particle size of the outer coating 363 satisfy: 5μm≤R2≤50μm. 5μm≤R3≤50μm.

[0120] In the above example, by ensuring that the inner coating 361 or the outer coating 363 meets the above conditions, the inner coating 361 and the outer coating 363 can provide a larger gap for the wound cell 3 after the wound cell 3 is wound and hot-pressed. This provides a larger expansion space for the wound cell 3, preventing the electrode 30 from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the cycle of the wound cell 3.

[0121] In one embodiment of this application, the wound cell 3 includes a flat region 34 and bent regions 35 located at opposite ends of the flat region 34, wherein at least a portion of the particle size R1 of the middle layer coating located in the flat region satisfies: 5μm≤R1≤50μm.

[0122] For example, the wound cell 3 includes two flat regions 34 and two bent regions 35 connected between the two flat regions 34, more specifically, combined with Figure 4 The two straight areas 34 are the first straight area 341 and the second straight area 342, respectively. The two bending areas 35 are the first bending area 351 and the second bending area 352, respectively. One end of the first straight area 341 is connected to one end of the first bending area 351. The other end of the first bending area 351 is connected to one end of the second straight area 342. The other end of the second straight area 342 is connected to one end of the second bending area 352. The other end of the second bending area 352 is connected to the other end of the first straight area 341.

[0123] Taking the first flat area 341 as an example, in the direction from the inner layer to the outer layer of the wound cell 3, the inner coating 361 can be located in the innermost layer of the wound cell 3, the outer coating 363 can be located in the outermost layer of the wound cell 3, and the middle coating 362 can be one layer, or two or more layers.

[0124] The particle size R1 of the intermediate coating 362 satisfies: 5μm≤R1≤50μm. During the winding process of the wound cell 3, the middle part located in the flat region 34 (i.e., the electrode 30, separator 33, and the intermediate coating 362 itself at the position of the intermediate coating 362) may experience more compression and deformation. By ensuring that the particle size of the intermediate coating 362 located in the flat region 34 meets the above conditions, the intermediate coating 362 located in the flat region 34 can have better mechanical strength, which helps to reduce the risk of damage to the intermediate coating 362 located in the flat region 34 during manufacturing. In addition, the battery will generate heat during use, especially under conditions of rapid charging and discharging or high ambient temperature. The middle part, being closer to the center of the wound cell 3, may experience higher temperatures. By ensuring that the particle size of the intermediate coating 362 meets the above conditions, the intermediate coating 362 can have better stability and withstand high temperatures better.

[0125] Finally, the particle size R1 of the intermediate coating 362 located in the flat region 34 satisfies: 5μm≤R1≤50μm. After the wound cell 3 is wound and hot-pressed, the intermediate coating 362 located in the flat region 34 can provide a larger gap for the middle part of the wound cell 3. In this way, firstly, it can provide a larger expansion space for the middle part of the wound cell 3, preventing the middle electrode 30 from breaking during cycling. Secondly, the larger gap can also facilitate the wetting of the electrolyte. In this way, in the later stage of the cycle of the wound cell 3, the risk of rapid life decay due to insufficient electrolyte wetting can be reduced.

[0126] For example, the particle size R1 of the intermediate coating 362 located in the flat region 34 can be 20 μm, 21 μm, 22 μm, 25 μm, 28 μm, 30 μm, 35 μm, 39 μm, 40 μm, 42 μm, 45 μm, 48 μm, or 50 μm. This example is merely illustrative and does not limit the particle size of the intermediate coating 362 in this application.

[0127] In the above example, by ensuring that the particle size of the intermediate coating 362 wound in the flat region 34 meets the above conditions, after the wound cell 3 is wound and hot-pressed, the intermediate coating 362 can provide a larger gap in the middle part of the wound cell 3. This firstly provides a larger expansion space for the middle part of the wound cell 3, preventing the middle electrode 30 from breaking during cycling. Secondly, the larger gap can also facilitate the wetting of the electrolyte. Thus, in the later stages of cycling of the wound cell 3, the risk of rapid life decay due to insufficient electrolyte wetting can be reduced.

[0128] In one embodiment of this application, the particle size R2 of the inner coating 361 and the particle size R3 of the outer coating 363 located in the flat region 34 satisfy: R2 < R1, and / or, R3 < R1.

[0129] In the above example, by ensuring that the inner coating 361 or the outer coating 363 meets the above conditions, the inner coating 361 and the outer coating 363 can provide a larger gap for the wound cell 3 after the wound cell 3 is wound and hot-pressed. This provides a larger expansion space for the wound cell 3, preventing the electrode 30 from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the cycle of the wound cell 3.

[0130] In one embodiment of this application, the particle size R2 of the inner coating 361 and the particle size R3 of the outer coating 363 located in the flat region 34 satisfy: 0.1μm≤R2<5μm, and / or, 0.1μm≤R3<5μm.

[0131] In the above example, by making the particle size of the inner coating 361 or the outer coating 363 meet the above conditions, the inner coating 361 and the outer coating 363 can be made more dense, which helps to improve the insulation effect of the wound cell 3. In addition, the electrolyte can be better wetted in the inner coating 361 and the outer coating 363 of the wound cell 3.

[0132] In one embodiment of this application, the particle size of the inner coating 361 located in the flat region 34 is R2, and the particle size of the outer coating 363 is R3, satisfying: 5μm≤R2<50μm, and / or, 5μm≤R3<50μm.

[0133] In the above example, by ensuring that the inner coating 361 or the outer coating 363 meets the above conditions, the inner coating 361 and the outer coating 363 can provide a larger gap for the wound cell 3 after the wound cell 3 is wound and hot-pressed. This provides a larger expansion space for the wound cell 3, preventing the electrode 30 from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the cycle of the wound cell 3.

[0134] In one embodiment of this application, at least a portion of the particle size R1 of the intermediate coating 362 located in the bending region 35 satisfies: 5μm≤R1≤50μm.

[0135] In the above example, by ensuring that the particle size of the intermediate coating 362 wound in the bending area 35 meets the above conditions, after the wound cell 3 is wound and hot-pressed, the intermediate coating 362 can provide a larger gap in the middle part of the wound cell 3. This firstly provides a larger expansion space for the middle part of the wound cell 3, preventing the middle electrode 30 from breaking during cycling. Secondly, the larger gap can also facilitate the wetting of the electrolyte. Thus, in the later stages of cycling of the wound cell 3, the risk of rapid life decay due to insufficient electrolyte wetting can be reduced.

[0136] In one embodiment of this application, the particle size R2 of the inner coating 361 and the particle size R3 of the outer coating 363 located in the bending region 35 satisfy: R2 < R1, and / or, R3 < R1.

[0137] In the above example, by ensuring that the inner coating 361 or the outer coating 363 meets the above conditions, the inner coating 361 and the outer coating 363 can provide a larger gap for the wound cell 3 after the wound cell 3 is wound and hot-pressed. This provides a larger expansion space for the wound cell 3, preventing the electrode 30 from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the cycle of the wound cell 3.

[0138] In one embodiment of this application, the particle size R2 of the inner coating 361 and the particle size R3 of the outer coating 363 located in the bending region 35 satisfy: 0.1μm≤R2<5μm, and / or, 0.1μm≤R3<5μm.

[0139] In the above example, by making the particle size of the inner coating 361 or the outer coating 363 meet the above conditions, the inner coating 361 and the outer coating 363 can be made more dense, which helps to improve the insulation effect of the wound cell 3. In addition, the electrolyte can be better wetted in the inner coating 361 and the outer coating 363 of the wound cell 3.

[0140] In one embodiment of this application, the particle size of the inner coating 361 located in the bending region 35 is R2, and the particle size of the outer coating 363 is R3, satisfying: 5μm≤R2<50μm, and / or, 5μm≤R3<50μm.

[0141] In the above example, by ensuring that the inner coating 361 or the outer coating 363 meets the above conditions, the inner coating 361 and the outer coating 363 can provide a larger gap for the wound cell 3 after the wound cell 3 is wound and hot-pressed. This provides a larger expansion space for the wound cell 3, preventing the electrode 30 from breaking during cycling. Secondly, the larger gap also facilitates electrolyte wetting, thus reducing the risk of rapid lifespan degradation due to insufficient electrolyte wetting in the later stages of the cycle of the wound cell 3.

[0142] In one embodiment of this application, in the direction from the inner layer to the outer layer of the wound cell 3, there is at least one intermediate coating 362 between the inner coating 361 and the outer coating 363.

[0143] For example, the intermediate coating 362 is provided with one layer. For instance, the wound cell 3 may have three coatings 36 in the flat region 34. The three coatings 36 are an inner coating 361, a middle coating 362, and an outer coating 363, respectively. The inner coating 361 is the outermost coating 36, the middle coating 362 is the middle coating 36, and the outer coating 363 is the innermost coating 36. It is understood that the wound cell 3 may also have four or five coatings in the flat region 34, etc., and this application does not impose any limitations.

[0144] For example, the intermediate coating 362 may also have two or more layers. For instance, the wound cell 3 may have N layers in the flat region 34, where N is greater than or equal to 4. The number of intermediate coatings 362 may be between 2 and N-2, and this application does not impose any restrictions.

[0145] In the above example, by arranging the number of intermediate coatings 362, a larger gap is provided in the middle part of the wound cell 3 (i.e., the electrode 30, the separator 33, and the intermediate coating 362 itself at the position of the intermediate coating 362). This firstly provides a larger expansion space at the intermediate coating 362 of the wound cell 3, and the more intermediate coatings 362 there are, the larger the expansion space, which can prevent the electrode 30 from breaking at the intermediate coating 362 during cycling. Secondly, the larger gap can also facilitate the wetting of the electrolyte at the intermediate coating 362. Thus, in the later stage of cycling of the wound cell 3, the electrolyte can better wet the intermediate coating 362, which can reduce the risk of rapid life decay of the intermediate coating 362 due to insufficient electrolyte wetting.

[0146] In one embodiment of this application, coating 36 is applied to at least one of diaphragm 33, first electrode 31, and second electrode 32.

[0147] For example, coating 36 can be applied to diaphragm 33, such as Figure 4 and Figure 5 As shown in one example, the wound cell 3 includes a first electrode 31 and a second electrode 32. The first electrode 31 is wound inside the second electrode 32. A separator 33 is provided between the first electrode 31 and the second electrode 32 as a first separator. A separator 33 is provided on the side of the second electrode 32 away from the first electrode 31 as a second separator. Both the inner and outer sides of the first separator are coated with a coating 36, and both the inner and outer sides of the second separator are coated with a coating 36.

[0148] For example, combined Figure 6 The coating 36 can be applied to both sides of the first electrode 31 and both sides of the second electrode 32.

[0149] For example, a portion of the coating 36 may be applied to the first electrode 31 or the second electrode 32, while another portion may be applied to the separator 33. This coating method only requires ensuring that there is one layer of coating 36 between the separator 33 and the first electrode 31, and between the separator 33 and the second electrode 32. It should be noted that the "one layer of coating 36" mentioned above is to reduce the amount of material used for coating 36 and to reduce excess coating 36, in order to facilitate the miniaturization of the wound cell 3. If the above factors are not considered, the coating 36 between the separator 33 and the first electrode 31, and between the separator 33 and the second electrode 32, may also be two layers, that is, coating 36 may be applied to the separator 33, the first electrode 31, and the second electrode 32.

[0150] In the above example, the arrangement of the coating position of the coating 36 can be flexibly arranged according to the actual production needs and performance requirements of the wound cell 3, thereby improving the flexibility and practicality of the wound cell 3.

[0151] In one embodiment of this application, in the winding direction, the coating 36 includes a first coating segment 41 and a second coating segment 42 connected together. The particle size of the first coating segment 41 is smaller than that of the second coating segment 42. The middle coating 362 is located in the second coating segment 42, and the inner coating 361 or the outer coating 363 is located in the first coating segment 41.

[0152] For example, combined Figure 7 , Figure 7This is a schematic diagram showing the particle size of the first, second, and third coating segments coated on both sides of the electrode in an unfolded state according to an embodiment. Coating 36 is applied to the diaphragm 33. When applying coating 36 to the diaphragm 33, the coating 36 can be applied in segments, resulting in two coating segments 36 on the electrode 30 in the winding direction, namely, the first coating segment 41 and the second coating segment 42. It should be noted that the insulating materials of the first coating segment 41 and the second coating segment 42 can be the same or different. For example, the insulating material can be a polymer composite (PCS), specifically polyethylene (PE), polypropylene (PP), etc. The insulating material can also be a ceramic coating, specifically alumina (Al2O3), barium titanate (BaTiO3), etc. This application does not limit the application in this regard.

[0153] In the above example, by making the coating 36 have both a first coating segment 41 with a relatively small particle size and a second coating segment 42 with a relatively large particle size, after the wound battery cell 3 is wound and hot-pressed, the first coating segment 41 enables the wound battery cell 3 to have good insulation, the second coating segment 42 enables the wound battery cell 3 to have good electrolyte wetting effect, and has a large expansion space, thereby improving the performance of the wound battery cell 3.

[0154] In some embodiments of this application, the inner coating 361 is located on the first coating segment 41. That is, the first coating segment 41 is wound around the inside of the second coating segment 42.

[0155] In the above example, by winding the first coating segment 41 inside the second coating segment 42, the first coating segment 41 enables the inner layer of the wound cell 3 to have better insulation, which in turn helps to improve the overall insulation effect of the wound cell 3.

[0156] In some embodiments of this application, coating 36 further includes a third coating segment 43 connected to one end of the second coating segment 42 away from the first coating segment 41, the third coating segment 43 being wound around the inner layer of the second coating segment 42, the third coating segment 43 including an outer coating 363, and the particle size of the third coating segment 43 being smaller than the particle size of the second coating segment 42.

[0157] In the above example, the third coating segment 43 is wound inside the second coating segment 42. That is, after the wound cell 3 is wound, the coating 36 located on the inner and outer sides has a smaller particle size than the coating 36 in the middle layer, which can provide better insulation for the wound cell 3. The second coating segment 42 located in the middle layer has a larger particle size, which can provide a larger expansion space and a better electrolyte wetting effect for the wound cell 3. This allows the wound cell 3 to have a good insulation effect, is less prone to damage from electrode breakage during cycling, and extends the service life of the wound cell 3.

[0158] In one embodiment of this application, the weight of the second coating segment 42 is greater than or equal to the weight of the first coating segment 41.

[0159] For example, the weight of the second coating segment 42 is greater than the weight of the first coating segment 41.

[0160] For example, the weight of the second coating segment 42 is equal to the weight of the first coating segment 41.

[0161] In the above example, by making the weight of the second coating segment 42 greater than or equal to the weight of the first coating segment 41, and with the particle size of the second coating segment 42 being larger than that of the first coating segment 41, the second coating segment 42 will be designed to be thicker or longer. In this way, after the wound cell 3 is wound, the second coating segment 42 will have a larger expansion space. On the one hand, this can provide stronger support for the wound cell 3 and reduce the risk that the insulation performance of the wound cell 3 will be affected by the larger particle size at the second coating segment 42. On the other hand, after the wound cell 3 is wound and hot-pressed, the second coating segment 42 can still have a larger gap, which is conducive to the wetting of the electrolyte and can reduce the risk of rapid life decay due to insufficient electrolyte wetting.

[0162] In one embodiment of this application, the weight of the second coating segment 42 is greater than or equal to the sum of the weights of the first coating segment 41 and the third coating segment 43.

[0163] For example, the weight of the second coating segment 42 is greater than the sum of the weights of the first coating segment 41 and the third coating segment 43.

[0164] For example, the weight of the second coating segment 42 is equal to the sum of the weights of the first coating segment 41 and the third coating segment 43.

[0165] In the above example, by making the weight of the second coating segment 42 greater than or equal to the sum of the weights of the first coating segment 41 and the third coating segment 43, and with the particle size of the second coating segment 42 being larger than that of the first coating segment 41, the second coating segment 42 will be designed to be thicker or longer. In this way, after the wound cell 3 is wound, the second coating segment 42 will have a larger expansion space. On the one hand, this can provide stronger support for the wound cell 3 and reduce the risk that the insulation performance of the wound cell 3 will be affected by the larger particle size at the second coating segment 42. On the other hand, after the wound cell 3 is wound and hot-pressed, the second coating segment 42 can still have a large gap, which is conducive to the wetting of the electrolyte and can reduce the risk of rapid life decay due to insufficient electrolyte wetting.

[0166] In one embodiment of this application, in the winding direction, the length of the coating 36 is L, and the length of the second coating segment 42 is L1, satisfying: 5% ≤ L1 / L ≤ 50%.

[0167] In the above example, by satisfying the above conditions, the second coating segment 42 can form a larger gap in the wound cell 3, which is beneficial for the wound cell 3 to expand during cycling and also beneficial for the wetting of the electrolyte.

[0168] In one embodiment of this application, coating 36 is applied to diaphragm 33. In the winding direction, the length of coating 36 is less than the length of diaphragm 33, and the length of coating 36 toward first electrode 31 is greater than or equal to the length of first electrode 31; the length of coating 36 toward second electrode 32 is greater than or equal to the length of second electrode 32.

[0169] In the above example, this difference makes the structure of the wound cell 3 compact. On the one hand, the length of the coating 36 facing the first electrode 31 is greater than or equal to the length of the first electrode 31. This ensures that the first electrode 31 is effectively insulated, preventing unnecessary electrical contact between the electrode 30 and other components, and ensuring the safety and stability of the battery. Similarly, the length of the coating 36 facing the second electrode 32 is greater than or equal to the length of the second electrode 32, which also serves the same purpose. Overall, this coating 36 design can optimize the electric field distribution inside the wound cell 3, reduce the risk of leakage, and at the same time, accurately insulate the electrode 30 without affecting the basic function of the separator 33, improving battery performance and reducing the probability of short circuits and other faults. This is of great significance in improving battery reliability.

[0170] This application also proposes a battery device 100 having the battery cell 20 described in the above embodiments.

[0171] In one embodiment of this application, a battery device 100 is provided. The battery device 100 includes a housing 10 and a battery cell 20. There is at least one battery cell 20. The battery cell 20 is installed inside the housing 10. The battery cell 20 includes a housing 22 and a wound cell 3. The wound cell 3 is located inside the housing 22.

[0172] In the above example, the battery cell 20 includes a wound cell 3. From the perspective of structural stability, the middle part of the wound cell 3 has a larger gap due to the middle coating 362, which helps maintain the structural integrity of the entire battery device 100 during its overall operation. The electrode 30 in the middle part of the cell is not easily broken during cycling, allowing the cells inside the battery device 100 to maintain a stable physical structure, avoiding local failures caused by the breakage of the electrode 30, thereby reducing the risk of short circuits or open circuits inside the battery device 100.

[0173] In terms of battery performance, the larger gaps facilitate electrolyte wetting, which is significant for improving the performance of the battery device 100. In the later stages of cycling, the cells within the battery device 100 can effectively avoid rapid lifespan degradation caused by insufficient electrolyte wetting. This means that the overall lifespan of the battery device 100 is extended, enabling it to maintain stable power output for a longer period. Furthermore, good electrolyte wetting facilitates ion transport within the battery, improving the charge and discharge efficiency of the battery device 100, reducing energy loss, and increasing overall energy density. This allows the battery device 100 to store and release more electrical energy within the same volume or weight, which is particularly crucial for applications such as electric vehicles that require high battery energy density.

[0174] The aforementioned battery device 100 can be applied to, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among these, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., while spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0175] Since the battery device 100 of this application adopts all the technical solutions of all the above embodiments, it also has all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0176] This application also proposes an electrical device having the battery device 100 of the above embodiments.

[0177] According to the embodiments of this application, the power-consuming device may include a battery device 100, which is used to store or provide electrical energy.

[0178] In the above example, by providing the battery device 100 described above, the power supply device of this application can have higher performance and a longer service life.

[0179] The battery cell 20, battery device 100, other components and operations of the power supply device according to the embodiments of this application are known to those skilled in the art and will not be described in detail here.

[0180] 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 this application. 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.

[0181] Although embodiments of this application 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 this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell (20), characterized in that, include: A wound battery cell (3) includes an electrode (30) and a separator (33). The electrode (30) and the separator (33) are wound in multiple layers along the winding direction to form the wound battery cell (3). A coating (36) is provided between the electrode (30) and the separator (33). In the direction from the inner layer to the outer layer, the coating (36) includes an inner coating (361), a middle coating (362) and an outer coating (363). The particle size R1 of at least a portion of the middle coating (362) satisfies: 5μm≤R1≤50μm.

2. The battery cell (20) according to claim 1, characterized in that, The particle size R2 of the inner coating (361) and the particle size R3 of the outer coating (363) satisfy: R2 < R1, and / or, R3 < R1.

3. The battery cell (20) according to claim 1 or 2, characterized in that, The particle size R2 of the inner coating (361) and the particle size R3 of the outer coating (363) satisfy: 0.1μm≤R2<5μm, and / or, 0.1μm≤R3<5μm.

4. The battery cell (20) according to claim 1 or 2, characterized in that, The particle size of the inner coating (361) is R2, and the particle size of the outer coating (363) is R3, satisfying: 5μm≤R2<50μm, and / or, 5μm≤R3<50μm.

5. The battery cell (20) according to claim 1, characterized in that, The wound cell (3) includes a flat region (34) and bent regions (35) located at opposite ends of the flat region (34), wherein at least a portion of the particle size R1 of the intermediate coating (362) located in the flat region (34) satisfies: 5μm≤R1≤50μm.

6. The battery cell (20) according to claim 5, characterized in that, The particle size R2 of the inner coating (361) located in the flat region (34) and the particle size R3 of the outer coating (363) satisfy: R2 < R1, and / or, R3 < R1.

7. The battery cell (20) according to claim 5 or 6, characterized in that, The particle size R2 of the inner coating (361) located in the flat region (34) and the particle size R3 of the outer coating (363) satisfy: 0.1μm≤R2<5μm, and / or, 0.1μm≤R3<5μm.

8. The battery cell (20) according to claim 5 or 6, characterized in that, The inner coating (361) located in the flat region (34) has a particle size of R2, and the outer coating (363) has a particle size of R3, satisfying: 5μm≤R2<50μm, and / or, 5μm≤R3<50μm.

9. The battery cell (20) according to any one of claims 5-8, characterized in that, The particle size R1 of at least a portion of the intermediate coating (362) located in the bending region (35) satisfies: 5μm≤R1≤50μm.

10. The battery cell (20) according to claim 9, characterized in that, The particle size R2 of the inner coating (361) located in the bending region (35) and the particle size R3 of the outer coating (363) satisfy: R2 < R1, and / or, R3 < R1.

11. The battery cell (20) according to claim 9 or 10, characterized in that, The particle size R2 of the inner coating (361) located in the bending region (35) and the particle size R3 of the outer coating (363) satisfy: 0.1μm≤R2<5μm, and / or, 0.1μm≤R3<5μm.

12. The battery cell (20) according to claim 9 or 10, characterized in that, The inner coating (361) located in the bending region (35) has a particle size of R2 and the outer coating (363) has a particle size of R3, satisfying: 5μm≤R2<50μm, and / or, 5μm≤R3<50μm.

13. The battery cell (20) according to any one of claims 1-12, characterized in that, In the direction from the inner layer to the outer layer of the wound cell (3), there is at least one middle layer coating (362) between the inner layer coating (361) and the outer layer coating (363).

14. The battery cell (20) according to any one of claims 1-12, characterized in that, The coating (36) is disposed on at least one of the diaphragm (33) and the electrode (30).

15. The battery cell (20) according to claim 1, characterized in that, In the winding direction, the coating (36) includes a first coating segment (41) and a second coating segment (42), wherein the particle size of the first coating segment (41) is smaller than that of the second coating segment (42), the middle coating (362) is located in the second coating segment (42), and the inner coating (361) or the outer coating (363) is located in the first coating segment (41).

16. The battery cell (20) according to claim 15, characterized in that, The coating (36) further includes a third coating segment (43) connected to one end of the second coating segment (42) away from the first coating segment (41), the third coating segment (43) being wound around the inner layer of the second coating segment (42), the particle size of the third coating segment (43) being smaller than the particle size of the second coating segment (42), one of the inner coating (361) and the outer coating (363) being located in the first coating segment (41) and the other being located in the third coating segment (43).

17. The battery cell (20) according to claim 15, characterized in that, The weight of the second coating segment (42) is greater than or equal to the weight of the first coating segment (41).

18. The battery cell (20) according to claim 16, characterized in that, The weight of the second coating segment (42) is greater than or equal to the sum of the weights of the first coating segment (41) and the third coating segment (43).

19. The battery cell (20) according to claim 15, characterized in that, In the winding direction, the length of the coating (36) is L, and the length of the second coating segment (42) is L1, satisfying: 5% ≤ L1 / L ≤ 50%.

20. The battery cell (20) according to claim 1, characterized in that, The coating (36) is applied to the diaphragm (33), and in the winding direction, the length of the coating (36) is less than the length of the diaphragm (33), and... The length of the coating (36) facing the electrode (30) is greater than or equal to the length of the electrode (30).

21. A battery device (100), characterized in that, include: Box (10): A battery cell (20), at least one of which is installed inside the housing (10), and the battery cell (20) is the battery cell (20) according to any one of claims 1-20.

22. An electrical appliance, characterized in that, Includes the battery device (100) of claim 21, the battery device (100) being used to store or provide electrical energy.

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