Battery, battery pack and electric equipment
By adjusting the position of the negative electrode, the problem of electrolyte overflow was solved, achieving efficient electrolyte wetting and improving the production efficiency and safety of lithium-ion batteries.
Patent Information
- Application Number
- CN202422042550.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2026-01-06
- Estimated Expiration
- 2034-08-21
AI Technical Summary
During the electrolyte injection process, the electrolyte wetting speed is slow, which causes electrolyte to overflow, affecting the appearance of the battery and causing waste.
By adjusting the position of the negative electrode to ensure that it does not overlap with the central axis of the positive electrode in the first direction and is offset from the direction of the injection hole, the electrolyte capacity inside the casing is increased, ensuring that the electrolyte can enter the casing in a timely manner.
It improves the wetting speed of the electrolyte, prevents electrolyte overflow, enhances production efficiency and product quality, reduces waste, and strengthens safety.
Smart Images
Figure CN223771311U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of lithium ion battery, concretely is a battery, battery pack and electric equipment. BACKGROUND
[0002] When the current industry common scheme is used to inject liquid, due to the slow speed of electrolyte infiltrating into the winding core, electrolyte overflow will occasionally occur when the injection speed is slightly fast, which not only leads to waste, but also causes the battery surface to turn white if the overflowed electrolyte is not cleaned, affecting the appearance. INVENTION CONTENTS
[0003] The application provides a battery, a battery pack and an electric device, by adjusting the relative position of the negative plate, more in-shell space can be reserved for electrolyte, so that the electrolyte can enter the shell in time. At the same time, the electrolyte absorption time can be shortened, and the winding core can be infiltrated by electrolyte faster. The problem of electrolyte overflow is solved, efficient electrolyte infiltration is realized, and the production efficiency and product quality are improved.
[0004] The application provides a battery, the battery comprises an electrode assembly and a shell; the electrode assembly comprises a positive plate, a diaphragm and a negative plate, the diaphragm is arranged between the positive plate and the negative plate, and the central axis of the negative plate in a first direction is not overlapped with the central axis of the positive plate in the first direction.
[0005] The shell comprises a liquid injection hole, and the liquid injection hole is arranged on the top or bottom of the shell perpendicular to the first direction.
[0006] The central axis of the negative plate in the first direction is offset away from the liquid injection hole.
[0007] In some embodiments, the projection of the positive plate and the negative plate in the direction perpendicular to the plane of the diaphragm does not exceed the projection range of the diaphragm.
[0008] In some embodiments, when the liquid injection hole is arranged on the top of the shell perpendicular to the first direction, the central axis of the negative plate in the first direction is below the central axis of the positive plate in the first direction.
[0009] In some embodiments, when the liquid injection hole is arranged on the bottom of the shell perpendicular to the first direction, the central axis of the negative plate in the first direction is above the central axis of the positive plate in the first direction away from the bottom.
[0010] In some embodiments, the central axis of the positive plate in the first direction away from the bottom is overlapped with the central axis of the diaphragm in the first direction. In some embodiments, the central axis of the positive plate in the first direction away from the bottom is overlapped with the central axis of the diaphragm in the first direction.
[0011] In some embodiments, the battery includes a wound cell placed in the housing, the wound cell being formed by stacking and winding the positive electrode, the separator, and the negative electrode.
[0012] In some embodiments, the battery is characterized in that it comprises stacked cells disposed in the housing, the stacked cells being formed by stacking at least one positive electrode, at least one separator, and at least one negative electrode.
[0013] In some embodiments, the positive electrode includes a positive electrode tab disposed at one end of the positive electrode perpendicular to a first direction, and the negative electrode includes a negative electrode tab disposed at one end of the negative electrode perpendicular to the first direction away from the positive electrode tab.
[0014] This application also provides a battery pack, which includes the battery described in any of the above embodiments.
[0015] This application also provides an electrical device, which includes the battery described in any of the above embodiments, and / or the battery pack described in any of the above embodiments.
[0016] In the battery of this application, during electrolyte filling, the negative electrode sheet is offset relative to the positive electrode sheet along its central axis in the first direction. This offset is directed away from the filling hole. This displacement reduces the volume of the negative electrode sheet near the filling hole within the casing. This reduction in volume increases the space available for electrolyte near the filling hole, allowing for more internal space to accommodate the injected electrolyte and enabling it to enter the casing more quickly without obstruction by the electrode sheet. This results in faster electrolyte injection into the casing, shortening the electrolyte absorption time and improving filling efficiency.
[0017] Additional aspects and advantages of embodiments 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 embodiments of this application. Attached Figure Description
[0018] 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, wherein:
[0019] Figure 1 This is a cross-sectional view of a battery according to certain embodiments of this application;
[0020] Figure 2 This is a cross-sectional view of an electrode assembly according to certain embodiments of this application;
[0021] Figure 3 This is a tiled view of the electrode assembly according to certain embodiments of this application;
[0022] Figure 4 This is a tiled view of a lithium-ion battery according to certain embodiments of this application;
[0023] Figure 5 This is a cross-sectional view of an electrode assembly according to certain embodiments of this application;
[0024] Figure 6 This is a plan view of the electrode assembly according to certain embodiments of this application.
[0025] Explanation of key component symbols:
[0026] Positive electrode: positive electrode plate; separator: separator; negative electrode: negative electrode plate; positive electrode & separator central axis: the central axis of the positive electrode and separator along the first direction; negative electrode central axis: the central axis of the negative electrode plate along the first direction. Detailed Implementation
[0027] 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 the embodiments of this application, and should not be construed as limiting the embodiments of this application.
[0028] In the description of this application, it should be understood that the terms "thickness," "upper," "top," "bottom," "inner," "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used 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. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.
[0029] Currently, the industry commonly uses a method where the negative electrode wraps around the positive electrode, with equal margins at both ends, meaning the central axes of the positive and negative electrode sheets are completely aligned, to wind or stack battery electrodes. This method is widely used. However, when using this common method to wind or stack the electrodes, the electrolyte wetting rate varies in real time during injection. Therefore, during the injection process, electrolyte may overflow from the injection hole because the electrode components cannot absorb it in time. This not only wastes electrolyte but also causes the battery surface to turn white, affecting its appearance. To solve these problems, this patent proposes the following solution: by adjusting the stacking method of the positive and negative electrode sheets, the electrolyte injection space within the casing is increased, thereby improving the electrolyte wetting rate.
[0030] This application provides a battery comprising a casing and an electrode assembly. The casing includes an injection hole disposed at the top or bottom of the casing perpendicular to a first direction. The electrode assembly includes a positive electrode, a separator, and a negative electrode, with the separator positioned between the positive and negative electrode. The central axis of the negative electrode in the first direction does not overlap with the central axis of the positive electrode in the first direction, and the central axis of the negative electrode is offset away from the injection hole. This provides more space within the casing near the injection hole to accommodate electrolyte, effectively preventing electrolyte overflow during the injection process. This not only solves the problem of electrolyte waste caused by overflow but also addresses the issue of whitening of the battery surface due to electrolyte overflow, which affects the battery's appearance.
[0031] Please see Figures 1-6 In some embodiments, during the electrode stacking process, the edges of both the positive and negative electrodes are within the edge range of the separator, meaning the separator can completely separate the positive and negative electrodes, preventing the electrode assembly from short-circuiting or causing other hazards due to contact between the positive and negative electrodes.
[0032] Please see Figures 1-6 In some embodiments, the positive electrode and the separator are aligned along the central axis of the first direction, that is, the positive electrode and the separator are stacked symmetrically in the center along the first direction.
[0033] Please see Figures 1-3In some embodiments, when the injection hole is at the upper end of the housing, i.e., near the positive electrode tab, the negative electrode sheet is offset away from the positive injection hole, meaning the central axis of the negative electrode sheet is offset downwards from the central axis of the positive electrode and the separator. After the central axis of the negative electrode sheet is offset away from the positive injection hole, there is more space in the housing near the positive injection hole to accommodate the electrolyte. Therefore, even if the injection speed is uneven, especially if the injection speed is slightly faster, or if the injection volume per unit time is higher, this increased space can hold more electrolyte, effectively preventing electrolyte from overflowing from the housing due to insufficient absorption by the electrode sheet after injection. Furthermore, because the area near the positive injection hole can hold more electrolyte, the gravity of this increased electrolyte will allow it to wet into the electrode assembly more quickly, accelerating the wetting process.
[0034] In some embodiments, coatings are applied to the current collector to form positive and negative electrodes. Typically, the coating for the positive electrode is a lithium-source active material such as lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, or lithium iron phosphate. The coating for the negative electrode is typically a layered structure material such as graphite, suitable for lithium atom insertion and extraction. During the coating and electrode fabrication process, the thickness of the coating at the edges of the current collector is greater than the thickness at the center of the coating area, resulting in a thicker coating at the edges. Current methods for fabricating positive and negative electrodes involve thinning the coating on the sides where the tabs are located, creating a thinned area. When the positive electrode is close to the thinned area of the negative electrode, the thinner coating in the thinned area prevents all lithium ions released from the positive electrode from embedding into the coating of the negative electrode, causing lithium ion adhesion to the surface of the negative electrode. This lithium ion adhesion easily forms dendrites, which may pierce the separator, causing a short circuit. (See also...) Figure 2 After the central axis of the negative electrode is shifted away from the positive electrode injection hole, the thinned area of the negative electrode is moved away from the positive electrode. Therefore, the implementation method of this application can reduce the risk of lithium plating and improve the safety of lithium-ion batteries.
[0035] Please see Figures 4-6In some embodiments, when the injection hole is at the lower end of the housing, i.e., near the negative electrode tab, the negative electrode sheet is offset away from the negative electrode injection hole, meaning the central axis of the negative electrode sheet is offset upwards towards the central axis of the positive electrode and the separator. After the central axis of the negative electrode sheet is offset away from the negative electrode injection hole, there is more space in the housing near the negative electrode injection hole to accommodate the electrolyte. Therefore, even if the injection speed is uneven, especially if the injection speed is slightly faster, or if the injection volume per unit time is higher, this increased space can hold more electrolyte, effectively preventing electrolyte from overflowing from the housing due to insufficient absorption by the electrode sheet after injection. Obviously, the casing may be flipped 180 degrees before the electrolyte is injected, so that the negative electrode injection hole is temporarily located at the top. At this time, since the part of the casing near the negative electrode injection hole can hold more electrolyte, the gravity of the more electrolyte will cause the electrolyte in the casing to wet the electrode more quickly, which can speed up the wetting speed of the electrolyte.
[0036] In some embodiments, the electrode assembly in the battery of this application is formed by stacking and winding a positive electrode sheet, a separator, and a negative electrode sheet. In this case, the casing shape of the lithium-ion battery can be cylindrical, elliptical, or other shapes.
[0037] In some embodiments, the electrode assembly in the battery provided in this application is formed by stacking a positive electrode, a separator, and a negative electrode. In this case, the shape of the lithium-ion battery casing can be rectangular, square, or other shapes. The shape of the casing can be the same as or different from the shape of the electrode or separator.
[0038] This application also provides a battery pack, which includes the battery provided in this application. Since the battery pack uses the battery provided in this application, it also possesses the aforementioned technical effects of the lithium-ion battery.
[0039] This application also provides an electrical device, which includes the battery pack and / or the battery provided in this application. Since the battery device uses the aforementioned battery pack, the electrical device provided in this application also possesses the technical effects of the aforementioned battery pack.
[0040] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with an embodiment or example that are 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.
[0041] 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 at least one of the stated features. In the description of this application, "multiple" means at least two, such as two or three, unless otherwise explicitly specified.
[0042] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. A battery, characterized by, The battery comprises an electrode assembly and a housing; the electrode assembly comprises a positive electrode sheet, a separator, and a negative electrode sheet, the separator is disposed between the positive electrode sheet and the negative electrode sheet, and the central axis of the negative electrode sheet in the first direction is not overlapped with the central axis of the positive electrode sheet in the first direction; The housing comprises a liquid injection hole, and the liquid injection hole is arranged on the top or bottom of the housing perpendicular to the first direction; The central axis of the negative electrode sheet in the first direction is offset away from the liquid injection hole.
2. The battery of claim 1, wherein, The projection of the positive electrode sheet and the negative electrode sheet in the direction perpendicular to the plane of the separator does not exceed the projection range of the separator.
3. The battery of claim 1, wherein, When the liquid injection hole is on the top of the housing perpendicular to the first direction, the central axis of the negative electrode sheet in the first direction is below the central axis of the positive electrode sheet in the first direction away from the top.
4. The battery of claim 1, wherein, When the liquid injection hole is on the bottom of the housing perpendicular to the first direction, the central axis of the negative electrode sheet in the first direction is above the central axis of the positive electrode sheet in the first direction away from the bottom.
5. The battery of claim 1, wherein, The central axis of the positive electrode sheet in the first direction is overlapped with the central axis of the separator in the first direction.
6. The battery according to any one of claims 1 to 5, wherein The battery comprises a wound cell, the wound cell is disposed in the housing, and the wound cell is formed by winding the positive electrode sheet, the separator, and the negative electrode sheet.
7. The battery according to any one of claims 1 to 5, wherein The battery comprises a stacked cell, the stacked cell is disposed in the housing, and the stacked cell is formed by stacking at least one positive electrode sheet, at least one separator, and at least one negative electrode sheet.
8. The battery of claim 1, wherein, The positive electrode sheet comprises a positive electrode tab arranged at one end of the positive electrode sheet perpendicular to the first direction, and the negative electrode sheet comprises a negative electrode tab arranged at one end of the negative electrode sheet away from the positive electrode tab perpendicular to the first direction.
9. A battery pack, characterized by, The battery comprises the battery of any one of claims 1-8.
10. An electric device, characterized by The battery comprises the battery of any one of claims 1-8, and / or the battery pack of claim 9.