An electric cell and a battery thereof
By designing normal and thinned sections on the positive electrode and covering the cut end face with adhesive tape to form an electrode receiving cavity, the problem of burrs piercing the separator during the cutting of thick electrodes is solved, achieving high energy density and safety of the battery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG LISUN ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-06-16
- Publication Date
- 2026-07-14
Smart Images
Figure CN224501973U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of batteries, and in particular to a battery cell and its battery. Background Technology
[0002] Currently, lithium-ion batteries are pursuing increasingly higher energy densities, resulting in thicker electrode sheets and thinner separators. When cutting thicker electrode sheets, the burrs at the head and tail become larger. When the separator is relatively thin, the burrs on the electrode sheet can easily puncture the separator, causing micro-short circuits inside the cell. Utility Model Content
[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. It provides a battery cell and its battery, reducing the difficulty of cutting thick positive electrode sheets and avoiding the formation of burrs during cutting, which could puncture the separator and cause a short circuit within the battery cell.
[0004] To achieve the above objectives, this utility model provides a battery cell having a first orientation, characterized in that it comprises:
[0005] The first diaphragm includes a diaphragm body, a first adhesive tape, and a second adhesive tape. The first adhesive tape is connected to one end of the diaphragm body in the first direction, and the second adhesive tape is connected to the other end of the diaphragm body in the first direction. An electrode receiving cavity is formed between the first adhesive tape and the second adhesive tape in the first direction.
[0006] A positive electrode sheet, comprising a normal section and a thinned section, wherein the thickness of the thinned section is less than the thickness of the normal section, the normal section is connected to the thinned section at both ends in the first direction, and the thinned section has a cut end face at one end in the first direction away from the normal section. The positive electrode sheet is connected to the electrode sheet receiving cavity and is attached to the separator body, wherein the first adhesive tape and the second adhesive tape respectively cover the cut end face at the corresponding position.
[0007] As a preferred embodiment, the thickness of the normal segment is Y μm, where 100 μm ≤ Y ≤ 160 μm.
[0008] As a preferred embodiment, any position of the thinning segment in the first direction is a set point, the thickness of the set point corresponding to the thinning segment is H μm, the distance from the set point to the cutting end face is L μm, and the thickness of the normal segment is Y μm, wherein H = K * L * Y, L > 0, K is the thinning coefficient, and 1% ≤ K ≤ 5%.
[0009] As a preferred embodiment, the positive electrode includes a foil and an active material layer. The active material layer is coated on opposite sides of the foil. The active material layer has a thinning slope at the end in the first direction on the side away from the foil. The thinning slope is located in the thinning section. The end of the thinning slope away from the normal section is inclined toward the foil. The thinning slope intersects with the cutting end face.
[0010] As a preferred embodiment, a portion of the first adhesive tape and a portion of the second adhesive tape are respectively connected to the first diaphragm, and the other portions of the first adhesive tape and the second adhesive tape are respectively covered and bonded to the thinning slope.
[0011] As a preferred embodiment, the length of the thinning segment in the first direction is set to 1mm-20mm.
[0012] As a preferred embodiment, the thickness of the first diaphragm is set between 3µm and 30µm.
[0013] As a preferred embodiment, the dimensions of the first adhesive tape and the second adhesive tape in the first direction are set to be between 5mm and 50mm.
[0014] As a preferred embodiment, the thickness of the first and second adhesive tapes is set between 15μm and 50μm.
[0015] A battery includes a negative electrode, a second separator, and a battery cell, wherein the first separator, the positive electrode, the second separator, and the negative electrode are stacked in sequence and wound along a first direction.
[0016] Compared with the prior art, the beneficial effects of this utility model embodiment of a battery cell and battery are as follows: The positive electrode sheet includes a normal section and a thinned section, the thickness of which is less than that of the normal section. The thinned section is connected to both ends of the normal section in the first direction, thereby avoiding the difficulty in cutting thicker positive electrode sheets and the formation of burrs. At the same time, it avoids the thicker positive electrode sheet directly squeezing the first separator, which could lead to the separator breaking in the later stages of cycling. The first separator is connected to a first adhesive tape and a second adhesive tape at both ends in the first direction. The first adhesive tape and the second adhesive tape are positioned corresponding to the cut end face of the positive electrode sheet. A pocket-shaped electrode sheet receiving cavity is formed between the first adhesive tape and the second adhesive tape. The positive electrode sheet is embedded in the electrode sheet receiving cavity. The two cut end faces of the positive electrode sheet in the first direction are respectively wrapped in the first adhesive tape and the second adhesive tape, preventing burrs after cutting from piercing the separator and causing a short circuit. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model.
[0018] Figure 2 This is a top view of the first diaphragm in an embodiment of this utility model.
[0019] Figure 3 This is a schematic diagram of the structure of the positive electrode sheet in an embodiment of this utility model.
[0020] Figure 4 This is a top view of the positive electrode sheet of an embodiment of this utility model.
[0021] In the picture:
[0022] 10. First diaphragm; 11. Diaphragm body; 12. First adhesive tape; 13. Second adhesive tape; 14. Electrode receiving cavity;
[0023] 20. Positive electrode sheet; 21. Normal section; 22. Thinning section; 23. Cut end face; 24. Foil sheet; 25. Active material layer; 26. Thinning bevel;
[0024] 30. Second diaphragm; 31. Negative electrode plate;
[0025] X, first direction; Y, second direction; Z, third direction. Detailed Implementation
[0026] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0027] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" used to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.
[0028] In the description of this utility model, it should be understood that the terms "connected," "linked," and "fixed," etc., used in this utility model should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a welded 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, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0029] like Figures 1 to 4 As shown, a preferred embodiment of the present invention provides a battery cell having a first direction X, comprising:
[0030] The first diaphragm 10 includes a diaphragm body 11, a first adhesive tape 12 and a second adhesive tape 13. The first adhesive tape 12 is connected to one end of the diaphragm body 11 in the first direction X, and the second adhesive tape 13 is connected to the other end of the diaphragm body 11 in the first direction X. An electrode receiving cavity 14 is formed between the first adhesive tape 12 and the second adhesive tape 13 in the first direction X.
[0031] The positive electrode 20 includes a normal section 21 and a thinning section 22. The thickness of the thinning section 22 is less than the thickness of the normal section 21. The normal section 21 is connected to the thinning section 22 at both ends in the first direction X. The thinning section 22 has a cut end face 23 at the end in the first direction X away from the normal section 21. The positive electrode 20 is connected to the electrode receiving cavity 14 and is attached to the separator body 11. The first adhesive tape 12 and the second adhesive tape 13 respectively cover the cut end face 23 at the corresponding positions.
[0032] A battery includes a negative electrode 31, a second separator 30, and a battery cell. The first separator 10, the positive electrode 20, the second separator 30, and the negative electrode 31 are stacked sequentially and wound along a first direction X. The first separator 10 is bonded with a first adhesive tape 12 and a second adhesive tape 13, while the second separator 30 is not bonded with adhesive tape.
[0033] The battery cell and battery of this utility model include a positive electrode 20 comprising a normal section 21 and a thinned section 22. The thickness of the thinned section 22 is less than that of the normal section 21. The thinned section 22 is connected to both ends of the normal section 21 in the first direction X, thereby avoiding the difficulty in cutting a thicker positive electrode 20 and the formation of burrs. At the same time, it avoids the thicker positive electrode 20 directly compressing the first separator 10, which could lead to the separator breaking in the later stages of cycling. The first separator 10 is connected to a first adhesive tape 12 and a second adhesive tape 13 at both ends in the first direction X. The first adhesive tape 12 and the second adhesive tape 13 are positioned corresponding to the cut end face 23 of the positive electrode 20. A pocket-shaped electrode receiving cavity 14 is formed between the first adhesive tape 12 and the second adhesive tape 13. The positive electrode 20 is embedded in the electrode receiving cavity 14. The two cut end faces 23 of the positive electrode 20 in the first direction X are respectively wrapped in the first adhesive tape 12 and the second adhesive tape 13, preventing burrs after cutting from piercing the separator and causing a short circuit.
[0034] As one embodiment, such as Figure 1 As shown, the active material of the negative electrode 31 is one or more of graphite, hard carbon, silicon carbide, silicon oxide, etc.
[0035] As one embodiment, such as Figure 1 As shown, the first diaphragm 10 and the second diaphragm 30 are made of one of the following materials: PE, PP, PE and PP composite materials, aramid, ceramic-coated membrane, and PVDF-coated membrane.
[0036] As one embodiment, such as Figures 1 to 2As shown, the first adhesive tape 12 and the second adhesive tape 13 are made of one or more of the following materials: PI, PET, PVC, etc. The needle-punch strength of the first adhesive tape 12 and the second adhesive tape 13 is required to be greater than or equal to 3000 kgf / cm². 2 .
[0037] Furthermore, such as Figure 3 As shown, the thickness of the normal section 21 is Y μm, where 100 μm ≤ Y ≤ 160 μm. The relatively large thickness of the normal section 21 of the positive electrode 20 helps to improve the energy density of the battery and meet the high energy density power requirements.
[0038] Furthermore, such as Figure 3 As shown, any position of the thinning segment 22 in the first direction X is a set point. The thickness of the thinning segment 22 corresponding to the set point is H μm, the distance from the set point to the cutting end face 23 in the first direction X is L μm, and the thickness of the normal segment 21 is Y μm. Here, H = K * L * Y, L > 0, K is the thinning coefficient, and 1% ≤ K ≤ 5%. According to this relationship, the closer the set point is to the cutting end face 23, the smaller the thickness of the thinning segment 22 corresponding to that set point. This avoids the thicker positive electrode sheet 20 compressing the first separator 10, and at the same time, the positive electrode sheet 20 is easier to cut, reducing the difficulty of the cutting operation.
[0039] Furthermore, such as Figure 3 As shown, the positive electrode 20 includes a foil 24 and an active material layer 25. The foil 24 is coated with the active material layer 25 on both opposite sides. Each end of the active material layer 25 facing away from the foil 24 in the first direction X has a thinning bevel 26 located in a thinning section 22. The end of the thinning bevel 26 away from the normal section 21 is inclined towards the foil 24, and intersects with the cut end face 23. The foil 24 provides a rigid substrate to support the positive active material layer 25 and prevent the coating from cracking or peeling during coating, rolling, or battery cycling. The foil 24 serves as an electron transport channel for the positive active material layer 25, collecting and conducting the current generated by the active material layer 25 to the external circuit. The active material layer 25 has a thinning slope 26 at its end in the first direction X. The thinning slope 26 is disposed in the thinning section 22, and the end of the thinning section 22 that is away from the normal section 21 in the first direction X is inclined toward the foil 24, thereby minimizing the thickness of the cutting end face 23, avoiding the compression of the first separator 10 by the thicker positive electrode 20, and making the positive electrode 20 easier to cut, reducing the difficulty of the cutting operation of the positive electrode 20.
[0040] As one embodiment, such as Figure 3 As shown, the active material layer 25 is made of one or more of lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and lithium nickel cobalt manganese oxide.
[0041] Furthermore, such as Figure 1 As shown, a portion of the first adhesive tape 12 and a portion of the second adhesive tape 13 are respectively connected to the first separator 10, and the remaining portions of the first adhesive tape 12 and the second adhesive tape 13 are respectively covered and bonded to the thinning slope 26. The portion of the first adhesive tape 12 and the portion of the second adhesive tape 13 connected to the first separator 10 secures the first adhesive tape 12 and the second adhesive tape 13. The remaining portions of the first adhesive tape 12 and the second adhesive tape 13 cover the thinning slope 26 to ensure complete coverage of the cut end face 23, preventing burrs formed after cutting from piercing the first separator 10 and causing an internal short circuit. Furthermore, the bonding of the first adhesive tape 12 and the second adhesive tape 13 to the thinning slope 26 secures the positive electrode 20, preventing displacement of the positive electrode 20 during winding and improving the reliability of the structure.
[0042] Furthermore, such as Figures 3 to 4 As shown, the length of the thinning section 22 in the first direction X is set between 1mm and 20mm so that the end of the positive electrode 20 is within a smaller thickness range, thus avoiding the problem of the thicker electrode directly squeezing the first separator 10 and breaking the first separator 10 in the later stage of cycling.
[0043] As one embodiment, such as Figures 3 to 4 As shown, the positive electrode 20 has a second direction Y and a third direction Z that are perpendicular to the first direction X. The dimension of the third direction Z of the positive electrode 20 is the thickness of the positive electrode 20, and the dimension of the second direction Y of the positive electrode 20 is the width of the positive electrode 20. The width of the positive electrode 20 is set between 1mm and 10000mm. The dimensions of the first adhesive tape 12 and the second adhesive tape 13 in the second direction Y are set to correspond to the dimensions of the positive electrode 20 in the second direction Y.
[0044] Furthermore, such as Figure 1 As shown, the thickness of the first separator 10 is set between 3µm and 30µm. The thickness of the first separator 10 can be adjusted according to the thickness of the positive electrode 20 to meet the space requirements and usage requirements inside the battery cell.
[0045] Furthermore, such as Figure 1 As shown, the dimensions of the first adhesive tape 12 and the second adhesive tape 13 in the first direction X are set between 5mm and 50mm, so that the first adhesive tape 12 and the second adhesive tape 13 can be partially bonded to the first separator 10 and completely cover the cut end face 23. A portion of the first adhesive tape 12 and the second adhesive tape 13 are bonded to the thinning slope 26, thereby fixing the positive electrode sheet 20 and improving the positional stability of the positive electrode sheet 20.
[0046] Furthermore, such as Figure 1As shown, the thickness of the first adhesive tape 12 and the second adhesive tape 13 is set between 15μm and 50μm. Setting the thickness of the first adhesive tape 12 and the second adhesive tape 13 within the set range ensures that the first adhesive tape 12 and the second adhesive tape 13 can meet the required bonding strength, while avoiding covering burrs and preventing punctures by burrs.
[0047] In summary, this utility model embodiment provides a battery cell and its battery. The positive electrode 20 includes a normal section 21 and a thinned section 22. The thickness of the thinned section 22 is less than the thickness of the normal section 21. The thinned section 22 is connected to both ends of the normal section 21 in the first direction X, thereby avoiding the difficulty in cutting the thicker positive electrode 20 and the easy formation of burrs. At the same time, it avoids the thicker positive electrode 20 directly squeezing the first separator 10, which would cause the separator to break in the later stage of cycling. The first diaphragm 10 is connected to a first adhesive tape 12 and a second adhesive tape 13 at its two ends in the first direction X. The first adhesive tape 12 and the second adhesive tape 13 are positioned corresponding to the cut end face 23 of the positive electrode 20. A pocket-shaped electrode receiving cavity 14 is formed between the first adhesive tape 12 and the second adhesive tape 13. The positive electrode 20 is embedded in the electrode receiving cavity 14. The two cut end faces 23 of the positive electrode 20 in the first direction X are respectively wrapped in the first adhesive tape 12 and the second adhesive tape 13, which avoids the burrs after cutting from piercing the diaphragm and causing a short circuit.
[0048] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this utility model, and these improvements and substitutions should also be considered within the protection scope of this utility model.
Claims
1. A battery cell having a first orientation, characterized in that, include: The first diaphragm includes a diaphragm body, a first adhesive tape, and a second adhesive tape. The first adhesive tape is connected to one end of the diaphragm body in the first direction, and the second adhesive tape is connected to the other end of the diaphragm body in the first direction. An electrode receiving cavity is formed between the first adhesive tape and the second adhesive tape in the first direction. A positive electrode sheet, comprising a normal section and a thinned section, wherein the thickness of the thinned section is less than the thickness of the normal section, the normal section is connected to the thinned section at both ends in the first direction, and the thinned section has a cut end face at one end in the first direction away from the normal section. The positive electrode sheet is connected to the electrode sheet receiving cavity and is attached to the separator body, wherein the first adhesive tape and the second adhesive tape respectively cover the cut end face at the corresponding position.
2. The battery cell according to claim 1, characterized in that: The thickness of the normal segment is Y μm, where 100 μm ≤ Y ≤ 160 μm.
3. The battery cell according to claim 2, characterized in that: The thinning segment is a set point at any position in the first direction. The thickness of the set point corresponding to the thinning segment is H μm. The distance from the set point to the cutting end face is L μm. The thickness of the normal segment is Y μm. Wherein, H = K * L * Y, L > 0, K is the thinning coefficient, and 1% ≤ K ≤ 5%.
4. The battery cell according to claim 1, characterized in that: The positive electrode includes a foil and an active material layer. The active material layer is coated on opposite sides of the foil. The active material layer has a thinning slope at the end in the first direction on the side away from the foil. The thinning slope is located in the thinning section. The end of the thinning slope away from the normal section is inclined toward the foil. The thinning slope intersects with the cutting end face.
5. The battery cell according to claim 4, characterized in that: A portion of the first adhesive tape and a portion of the second adhesive tape are respectively connected to the first diaphragm, and the other portions of the first adhesive tape and the second adhesive tape are respectively covered and bonded to the thinning slope.
6. The battery cell according to claim 1, characterized in that: The length of the thinning segment in the first direction is set between 1mm and 20mm.
7. The battery cell according to claim 1, characterized in that: The thickness of the first diaphragm is set between 3µm and 30µm.
8. The battery cell according to claim 1, characterized in that: The dimensions of the first adhesive tape and the second adhesive tape in the first direction are set between 5mm and 50mm.
9. The battery cell according to claim 1, characterized in that: The thickness of the first and second adhesive tapes is set between 15μm and 50μm.
10. A battery, characterized in that: The battery includes a negative electrode, a second separator, and a battery cell as described in any one of claims 1-9, wherein the first separator, the positive electrode, the second separator, and the negative electrode are stacked in sequence and wound along the first direction.