Battery monomer, battery and electric device

Abstract

The utility model relates to a battery monomer, a battery and a power utilization device. The single battery comprises a shell with an accommodating cavity, and a constant-pressure buffer layer is arranged on the wall surface of one side, close to the accommodating cavity, of the shell; and the battery cell is accommodated in the accommodating cavity of the shell, and at least part of the constant-voltage buffer layer and the side wall of the battery cell are correspondingly arranged at intervals. According to the battery monomer provided by the invention, the constant-voltage buffer layer and the side wall of the battery cell are correspondingly arranged, and the constant-voltage buffer layer can apply uniform and continuous counter-acting force to the battery cell along with expansion of the battery cell in a pre-charging formation stage of the battery cell, so that gas generated during formation of the battery cell is eliminated; the constant-voltage buffer layer and the side wall of the battery cell are arranged at intervals, so that an expansion space of the battery cell is reserved, meanwhile, the constant-voltage buffer layer buffers deformation caused by expansion of the battery cell, and the structural stability and the electrochemical performance of the single battery are considered; in addition, in the cycle stage of the battery cell, the constant pressure buffer layer simulates the constant pressure process applied to the battery cell, and the cycle performance of the battery is improved.

Description

Technical Field

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

[0002] During the charge and discharge process of the battery, the battery cell will expand and squeeze the battery casing. When the expansion of the battery cell is large, it will cause problems such as deformation of the battery casing and failure of the battery cell.

[0003] In conventional technology, the volume of the battery casing is usually set to be larger than the volume of the battery cell to reserve space for the cell to expand.

[0004] However, the battery cell does not fit fully into the battery casing during formation, and the battery casing cannot exert sufficient pressure on the battery cell during the formation process, resulting in black spots on the negative electrode and ineffective removal of gases generated during the formation of the battery cell, which affects the electrochemical performance of the battery. In addition, the applicant has discovered that applying a certain amount of pressure to the battery cell during the cycling process is beneficial to improving cycling performance. Utility Model Content

[0005] Based on this, it is necessary to provide a battery cell, a battery and an electrical device to solve the above technical problems.

[0006] The first aspect of the present application provides a battery cell, which includes: a shell having a accommodating cavity, a constant-voltage buffer layer being provided on the wall surface of the shell close to the accommodating cavity; and a battery cell accommodated in the accommodating cavity of the shell, at least part of the constant-voltage buffer layer being arranged correspondingly to the side wall of the battery cell.

[0007] In some embodiments, the shell includes a bottom plate and a side plate connected to the periphery of the bottom plate, the constant voltage buffer layer includes a first constant voltage buffer portion arranged on the side plate, and at least a portion of the first constant voltage buffer portion is arranged to correspond to the side wall of the battery cell.

[0008] In some embodiments, the constant voltage buffer layer further includes: a second constant voltage buffer portion, disposed on the bottom plate, the second constant voltage buffer portion is connected to the first constant voltage buffer portion, and the battery cell is disposed in the second constant voltage buffer portion.

[0009] In some embodiments, the battery cell further includes: a cover plate assembly, the cover plate assembly includes a cover plate, the cover plate covers the accommodating cavity, and the cover plate assembly is used to seal the shell.

[0010] In some embodiments, a positive electrode tab and a negative electrode tab are provided on the battery cell, a positive electrode post and a negative electrode post are provided on the cover plate, the positive electrode tab is connected to the positive electrode post, and the negative electrode tab is connected to the negative electrode post.

[0011] In some embodiments, a liquid injection hole is provided on the cover plate, and the liquid injection hole is used to inject electrolyte into the shell.

[0012] In some embodiments, an explosion-proof valve is provided on the cover plate, and an explosion pressure threshold of the explosion-proof valve is lower than the explosion pressure threshold of the housing.

[0013] In some embodiments, the constant pressure buffer layer is a silicone rubber layer or a fluororubber layer.

[0014] In some embodiments, the housing is a square housing.

[0015] In some embodiments, the battery cell includes a negative electrode plate, the negative electrode plate includes a negative electrode active material capable of reversibly extracting and inserting metal ions, and the negative electrode active material includes a silicon-based material.

[0016] A second aspect of the present application provides a battery, which includes the battery cell provided by the first aspect.

[0017] A third aspect of the present application provides an electrical device, which includes the battery provided in the second aspect.

[0018] Compared with traditional technologies, this application has at least the following beneficial effects:

[0019] The battery cell provided in the present application has a constant-pressure buffer layer arranged corresponding to the side wall of the battery cell. During the pre-charging and formation stage of the battery cell, as the battery cell expands, pressure is applied to the constant-pressure buffer layer. The constant-pressure buffer layer can automatically adapt to the pressure change and apply a uniform and continuous reaction force to the battery cell, thereby reducing negative electrode black spots and eliminating the gas generated during the formation of the battery cell. The constant-pressure buffer layer is spaced apart from the side wall of the battery cell, reserving expansion space for the battery cell. At the same time, the constant-pressure buffer layer can buffer the deformation caused by the expansion of the battery cell, reduce the deformation of the shell, and take into account the structural stability and electrochemical performance of the battery cell. In addition, during the battery cell cycling stage, the constant-pressure buffer layer simulates the constant pressure process applied to the battery cell, which is beneficial to improving the battery cycling performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the explosion structure of a battery cell in one embodiment of the present application.

[0021] Figure 2 This is a schematic diagram of the three-dimensional structure of the shell and the constant pressure buffer layer when used together in one embodiment of the present application.

[0022] Figure 3 This is a schematic top view of the structure when the shell and the constant pressure buffer layer are used together in one embodiment of the present application.

[0023] Figure 4 for Figure 3 A schematic cross-sectional view of the embodiment along AA is shown.

[0024] Description of Reference Numerals

[0025] 1. Battery cells;

[0026] 10. Shell; 11. Accommodation chamber; 12. Bottom plate; 13. Side plate;

[0027] 20. Constant pressure buffer layer; 21. First constant pressure buffer portion; 22. Second constant pressure buffer portion;

[0028] 30. Battery cell; 31. Positive terminal lug; 32. Negative terminal lug;

[0029] 40. Cover plate assembly; 41. Cover plate; 411. Positive pole; 412. Negative pole; 413. Liquid injection hole; 414. Explosion-proof valve; 42. Tab pin. DETAILED DESCRIPTION

[0030] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0031] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0032] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0033] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0034] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0035] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0036] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0037] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied if any of the following conditions are met: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0038] During the charge and discharge process of the battery, the battery cell will expand and squeeze the battery casing. When the expansion of the battery cell is large, it will cause problems such as deformation of the battery casing and failure of the battery cell.

[0039] In conventional technology, the volume of the battery casing is usually set to be larger than the volume of the battery cell to reserve space for the cell to expand.

[0040] However, the battery cell does not fit fully into the battery casing during formation, and the battery casing cannot exert sufficient pressure on the battery cell during the formation process, resulting in black spots on the negative electrode and ineffective removal of gases generated during the formation of the battery cell, which affects the electrochemical performance of the battery. In addition, the applicant has discovered that applying a certain amount of pressure to the battery cell during the cycling process is beneficial to improving cycling performance.

[0041] In order to solve the above technical problems, see Figures 1 to 4 As shown, the first aspect of the present application provides a battery cell 1, which includes a housing 10 and a battery cell 30. The housing 10 has a receiving cavity 11, and a constant voltage buffer layer 20 is provided on the wall surface of the housing 10 adjacent to the receiving cavity 11. The battery cell 30 is accommodated in the receiving cavity 11 of the housing 10, and at least a portion of the constant voltage buffer layer 20 is spaced apart and arranged correspondingly to the side wall of the battery cell 30.

[0042] The battery cell 1 provided in the present application has a constant-voltage buffer layer 20 arranged corresponding to the side wall of the battery cell 30. During the pre-charging and formation stage of the battery cell 30, as the battery cell 30 expands, pressure is applied to the constant-voltage buffer layer 20. The constant-voltage buffer layer 20 can automatically adapt to the pressure change and apply a uniform and continuous reaction force to the battery cell 30, thereby reducing negative electrode black spots and eliminating the gas generated when the battery cell 30 is formed. The constant-voltage buffer layer 20 is spaced apart from the side wall of the battery cell 30, reserving expansion space for the battery cell 30. At the same time, the constant-voltage buffer layer 20 can buffer the deformation caused by the expansion of the battery cell 30, reduce the deformation of the shell 10, and take into account the structural stability and electrochemical performance of the battery cell 1. In addition, during the cycle stage of the battery cell 30, the constant-voltage buffer layer 20 simulates the constant pressure process applied to the battery cell 30, which is beneficial to improving the cycle performance of the battery.

[0043] In some embodiments, such as Figure 4 As shown, the housing 10 includes a bottom plate 12 and side plates 13 connected to the periphery of the bottom plate 12. The constant-voltage buffer layer 20 includes a first constant-voltage buffer portion 21 provided on the side plate 13. At least a portion of the first constant-voltage buffer portion 21 is spaced and aligned with the sidewalls of the battery cell 30. By providing the first constant-voltage buffer portion 21 on the side plate 13 and spaced and aligned with the sidewalls of the battery cell 30, space is reserved for the battery cell 30 to expand, simulating a constant pressure process applied to the battery cell 30. This buffers the expansion pressure, reduces deformation of the housing 10 caused by the expansion of the battery cell 30, and improves both the structural stability and the cycling stability of the battery.

[0044] In some embodiments, such as Figures 2 to 4As shown, the constant voltage buffer layer 20 further includes a second constant voltage buffer portion 22, which is disposed on the bottom plate 12 and connected to the first constant voltage buffer portion 21. The battery cell 30 is disposed in the second constant voltage buffer portion 22. Providing the second constant voltage buffer portion 22 on the bottom plate 12 provides support for the bottom of the battery cell 30, thereby improving the overall buffering effect of the battery cell 1, reducing vertical deformation of the battery cell 30 and the housing 10 during formation and cycling, and enhancing the structural and electrochemical stability of the battery cell 1.

[0045] In some implementations, such as Figure 1 As shown, the battery cell 1 further includes a cover plate assembly 40, which includes a cover plate 41. The cover plate 41 covers the accommodating cavity 11, and the cover plate assembly 40 is used to seal the housing 10. The cover plate assembly 40 is used to seal the housing 10, ensuring the sealing of the battery interior, preventing electrolyte leakage or the ingress of external contaminants, and improving the safety of the battery.

[0046] In some embodiments, such as Figure 1 As shown, the battery cell 30 is provided with a positive electrode ear 31 and a negative electrode ear 32, and the cover plate 41 is provided with a positive electrode column 411 and a negative electrode column 412. The positive electrode ear 31 is connected to the positive electrode column 411, and the negative electrode ear 32 is connected to the negative electrode column 412. In the embodiment of the present application, the electrical connection between the battery cell 30 and the external circuit is achieved through the connection structure between the positive electrode ear 31 and the positive electrode column 411, and the negative electrode ear 32 and the negative electrode column 412. Specifically, the positive electrode ear 31 and the negative electrode ear 32 can be directly connected to the positive electrode column 411 and the negative electrode column 412 by welding or the like, or can be indirectly connected to the positive electrode column 411 and the negative electrode column 412 by other components. For example, as Figure 1 As shown, in one embodiment of the present application, the positive tab 31 is connected to the positive electrode post 411, and the negative tab 32 is connected to the negative electrode post 412 via tab pins 42. The tab pins 42 are L-shaped, which is suitable for the battery cell 30 to extend positive and negative tabs from both sides. In other embodiments, the tab pins 42 are straight, which is more suitable for winding cores with tabs extending from the same side. Of course, these two structures and tab extension methods are not fixed and can be selected according to actual needs.

[0047] In some implementations, such as Figure 1 As shown, the cover plate 41 is provided with an injection hole 413 for injecting electrolyte into the housing 10. It should be noted that after the electrolyte is injected, a sealing plug is inserted into the injection hole 413, and a metal sheet is placed above the injection hole 413 for welding to ensure the sealing performance of the battery cell 1.

[0048] In some implementations, such as Figure 1As shown, the cover plate 41 is provided with an explosion-proof valve 414, whose explosion pressure threshold is lower than that of the battery housing 10. As the internal pressure of the battery cell 1 continues to increase, the internal pressure of the battery cell 1 first reaches the explosion pressure threshold of the explosion-proof valve 414, causing the explosion-proof valve 414 to open first, thereby releasing the internal pressure of the battery cell 1 and preventing the housing 10 from exploding. Specifically, the explosion-proof valve 414 includes an explosion-proof membrane and a protective sheet. The protective sheet is provided above the explosion-proof membrane, and the explosion-proof membrane is provided with a weak portion. The explosion pressure threshold of the weak portion is lower than that of the battery housing 10. If the weak portion explodes, the protective sheet can collect the explosion fragments from the weak portion, preventing the explosion fragments from being splashed.

[0049] In some embodiments, the constant-voltage buffer layer 20 is a silicone rubber layer or a fluororubber layer. In the embodiments of the present application, the silicone rubber layer or fluororubber layer has a certain toughness. As the battery cell 30 expands, it applies pressure to the silicone rubber layer or fluororubber layer. The silicone rubber layer or fluororubber layer reacts on the battery cell 30, causing the battery cell 30 to be subjected to pressure and expelling the gas generated by the battery cell 30 during formation. At the same time, because the silicone rubber layer or fluororubber layer has a certain elasticity, it can buffer the deformation caused by the expansion of the battery cell 30, reducing the deformation of the housing 10, thereby taking into account both the structural stability and electrochemical performance of the battery cell 1.

[0050] In some embodiments, the housing 10 may also be used to contain an electrolyte, such as an electrolyte solution.

[0051] In some embodiments, the housing 10 may be in various structural forms, such as square, cylindrical, hexagonal, etc. Specifically, the shape of the housing 10 may be determined according to the specific shape and size of the battery cell 30. Optionally, the housing 10 is a square housing 10.

[0052] In some embodiments, the housing 10 may be made of a conductive metal material or plastic. Optionally, the housing 10 is made of aluminum or an aluminum alloy.

[0053] In some embodiments, the battery cell 30 includes a negative electrode plate, the negative electrode plate includes a negative electrode active material capable of reversibly extracting and inserting metal ions, and the negative electrode active material includes a silicon-based material.

[0054] Silicon-based negative electrode systems have high energy density, however, silicon-based materials undergo significant expansion during charge and discharge. Therefore, the battery cell 1 provided in this application is particularly suitable for battery cells 30 having silicon-based negative electrode systems.

[0055] A second aspect of the present application provides a battery, which includes the battery cell 1 provided in the first aspect.

[0056] In a battery, there can be one or more battery cells 1. If there are multiple battery cells 1, they can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections within the battery cells 1. Multiple battery cells 1 can be directly connected in series, in parallel, or in a hybrid connection. Alternatively, multiple battery cells 1 can be connected in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a whole. Multiple battery cells 1 within a battery module can be electrically connected via a busbar to enable parallel, series, or hybrid connection of multiple battery cells 1 within the battery module.

[0057] The third aspect of the present application provides an electrical device, which includes the battery provided in the second aspect. The battery is used to provide electrical energy to the electrical device.

[0058] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0059] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the technical concept of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A battery cell, characterized in that: include: A housing having a housing cavity, wherein a constant pressure buffer layer is provided on a wall surface of the housing close to the housing cavity; and The battery core is accommodated in the accommodating cavity of the shell, and at least a portion of the constant voltage buffer layer is spaced apart and correspondingly arranged to the side wall of the battery core.

2. The battery cell according to claim 1, wherein: The shell includes a bottom plate and a side plate connected to the periphery of the bottom plate. The constant voltage buffer layer includes a first constant voltage buffer portion arranged on the side plate. At least part of the first constant voltage buffer portion is spaced correspondingly from the side wall of the battery cell.

3. The battery cell according to claim 2, characterized in that: The constant voltage buffer layer further includes: The second constant voltage buffer part is arranged on the bottom plate, the second constant voltage buffer part is connected to the first constant voltage buffer part, and the battery cell is arranged in the second constant voltage buffer part.

4. The battery cell according to claim 1, wherein: Also includes: A cover plate assembly includes a cover plate, the cover plate covers the accommodating cavity, and the cover plate assembly is used to seal the shell.

5. The battery cell according to claim 4, characterized in that The battery cell is provided with a positive electrode tab and a negative electrode tab, the cover plate is provided with a positive electrode column and a negative electrode column, the positive electrode tab is connected to the positive electrode column, and the negative electrode tab is connected to the negative electrode column.

6. The battery cell according to claim 4, characterized in that The cover plate is provided with a liquid injection hole, and the liquid injection hole is used to inject electrolyte into the shell; and / or, An explosion-proof valve is provided on the cover plate, and an explosion pressure threshold of the explosion-proof valve is lower than the explosion pressure threshold of the shell.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The constant pressure buffer layer is a silicone rubber layer or a fluororubber layer.

8. The battery cell according to any one of claims 1 to 6, characterized in that: The housing is a square housing; and / or, The battery cell includes a negative electrode plate, the negative electrode plate includes a negative electrode active material capable of reversibly extracting and inserting metal ions, and the negative electrode active material includes a silicon-based material.

9. A battery, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: Comprising the battery of claim 9.

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