Battery cell and battery
By setting a cavity between the electrode and the separator in the battery cell, the problem of insufficient electrolyte is solved, which promotes the migration of active ions, inhibits lithium plating, and improves the battery's long cycle life and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUIZHOU LIWINON ELECTRONIC TECH CO LTD
- Filing Date
- 2024-12-24
- Publication Date
- 2026-05-19
AI Technical Summary
During charge-discharge cycles, especially in fast and ultra-fast charging systems, existing batteries often experience insufficient electrolyte on the outer side of the cell, which hinders the transport of active ions and leads to lithium plating, affecting the battery's long cycle life and safety.
A cavity is provided between the first and second electrodes of the battery cell to hold the electrolyte, thereby increasing the electrolyte retention capacity, promoting the migration of active ions, and suppressing lithium plating on the negative electrode.
By increasing the electrolyte retention, lithium plating on the negative electrode of the battery cell is suppressed, the thickness expansion rate of the battery is reduced, and the battery's long cycle life and safety are improved.
Smart Images
Figure CN224264255U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to a battery cell and a battery. Background Technology
[0002] Existing batteries have a low electrolyte retention capacity on the outer part of the cell. During charge-discharge cycles, especially in fast and ultra-fast charging systems, insufficient electrolyte on the outer part of the cell can easily lead to obstruction of the transport of active ions between the positive and negative electrodes. This makes it difficult for active ions to return from the negative electrode to the positive electrode, causing lithium plating on the outer second electrode of the cell. This results in phenomena such as dotted black spots, local pitting, and cell thickening, which in turn increases the battery's thickness expansion rate and affects the battery's long cycle life and safety performance.
[0003] Therefore, there is an urgent need for a type of battery cell and battery to solve the above problems. Utility Model Content
[0004] The purpose of this invention is to provide a battery cell and battery that improves the electrolyte retention of the first and second ends of the battery cell.
[0005] To achieve the above objectives, this utility model provides a battery cell, including a first electrode, a separator, and a second electrode. Multiple first electrodes, separators, and second electrodes are provided. The first electrodes and second electrodes are alternately arranged along a first direction. One of the first electrodes and the second electrodes is a positive electrode, and the other is a negative electrode. The separator is sandwiched between the first electrodes and the second electrodes.
[0006] The first electrode includes a first current collector and a first coating applied to the side of the first current collector, with the first coating sandwiched between the first current collector and an adjacent diaphragm. The second electrode includes a second current collector and a second coating applied to the side of the second current collector, with the second coating sandwiched between the second current collector and an adjacent diaphragm.
[0007] The separator closest to the first end of the battery cell is the first separator, and the separator closest to the second end of the battery cell is the second separator. Both the first separator and the second separator are sandwiched between the first electrode and the second electrode.
[0008] A receiving cavity is provided on a first coating adjacent to the first diaphragm and / or on a second coating adjacent to the first diaphragm, and the receiving cavity is provided on a first coating adjacent to the second diaphragm and / or on a second coating adjacent to the second diaphragm, the receiving cavity being used to contain electrolyte.
[0009] As an improvement to the above technical solution, the receiving cavity is provided on both the first coating adjacent to the first diaphragm and the second coating adjacent to the first diaphragm, and the receiving cavity is provided on both the first coating adjacent to the second diaphragm and the second coating adjacent to the second diaphragm.
[0010] As an improvement to the above technical solution, the receiving cavity located on the first coating penetrates the first coating along the second direction, and the receiving cavity located on the second coating penetrates the second coating along the second direction, wherein the second direction is perpendicular to the first direction.
[0011] As an improvement to the above technical solution, the height of the receiving cavity along the first direction is H1, and the heights of the first coating and the second coating along the first direction are H, where H1 < H.
[0012] As an improvement to the above technical solution, a plurality of receiving cavities are provided on the first coating adjacent to the first diaphragm and on the second coating adjacent to the first diaphragm, and a plurality of receiving cavities are provided on the first coating adjacent to the second diaphragm and on the second coating adjacent to the second diaphragm, and the third direction is perpendicular to the first direction and is set at an angle to the second direction.
[0013] As an improvement to the above technical solution, the third direction is perpendicular to the second direction.
[0014] As an improvement to the above technical solution, the total volume of the accommodating cavity on the first coating adjacent to the first diaphragm is V1, and the total volume of the first coating on the first electrode adjacent to the first diaphragm is V; the total volume of the accommodating cavity on the second coating adjacent to the first diaphragm is V1, and the total volume of the second coating on the second electrode adjacent to the first diaphragm is V; the total volume of the accommodating cavity on the first coating adjacent to the second diaphragm is V1, and the total volume of the first coating on the first electrode adjacent to the first diaphragm is V; the total volume of the accommodating cavity on the second coating adjacent to the second diaphragm is V1, and the total volume of the second coating on the second electrode adjacent to the first diaphragm is V; 0 < V1 / V < 15%.
[0015] As an improvement to the above technical solution, V1 / V is 7.5%.
[0016] As an improvement to the above technical solution, a plurality of first grooves are provided on the first coating and the second coating adjacent to the first diaphragm, and the first grooves and the adjacent first diaphragm surround to form the receiving cavity;
[0017] Multiple second grooves are provided on the first coating and the second coating adjacent to the second diaphragm, and the second grooves and the adjacent second diaphragm surround the receiving cavity.
[0018] A battery comprising a cell as described in any of the preceding claims, further comprising a housing and an electrolyte, wherein the cell is disposed within the housing and the housing is filled with the electrolyte.
[0019] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0020] The battery cell of this invention has a cavity at the first and second ends that can provide a certain electrolyte storage space to increase the electrolyte retention at the first and second ends of the cell, promote the migration of active ions at the first and second ends of the cell during charge and discharge cycles, and suppress the formation of lithium plating, spot-like black spots, local pitting, and cell thickening on the negative electrode plates at the first and second ends of the cell. This reduces the thickness expansion rate of the battery and improves the battery's long cycle life and other performance characteristics. Attached Figure Description
[0021] Figure 1 This is a partial structural schematic diagram of the battery cell provided in an embodiment of the present utility model;
[0022] Figure 2 This is a side view of the second coating of the battery cell provided in this embodiment of the present invention;
[0023] Figure 3 This is a top view of the second coating of the battery cell provided in this embodiment of the present invention.
[0024] In the picture:
[0025] Z, first direction; X, second direction; Y, third direction;
[0026] 1. First electrode; 11. First current collector; 12. First coating;
[0027] 2. Second electrode; 21. Second current collector; 22. Second coating;
[0028] 3. First diaphragm;
[0029] 4. Second diaphragm;
[0030] 5. Third diaphragm;
[0031] 10. Receiving cavity. Detailed Implementation
[0032] 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.
[0033] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0035] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.
[0036] like Figures 1-3As shown, this embodiment provides a battery cell, including a first electrode 1, a separator, and a second electrode 2. Multiple first electrode 1s, separators, and second electrode 2s are provided. The first electrode 1s and second electrode 2s are alternately arranged along a first direction Z. One of the first electrode 1s and the second electrode 2 is a positive electrode, and the other is a negative electrode. A separator is sandwiched between each of the first electrode 1s and the second electrode 2s. The first electrode 1 includes a first current collector 11 and a first coating 12 coated on the side of the first current collector 11. The first coating 12 is sandwiched between the first current collector 11 and adjacent separators. The second electrode 2 includes a second current collector 21 and a second coating 22 coated on the side of the second current collector 21. The second coating 22 is sandwiched between the second current collector 21 and adjacent separators. The battery cell has a first end and a second end disposed opposite to each other along a first direction Z. The separator closest to the first end of the battery cell is the first separator 3, and the separator closest to the second end of the battery cell is the second separator 4. Both the first separator 3 and the second separator 4 are sandwiched between the first electrode 1 and the second electrode 2. A receiving cavity 10 is provided on the first coating 12 adjacent to the first separator 3 and / or on the second coating 22 adjacent to the first separator 3. A receiving cavity 10 is provided on the first coating 12 adjacent to the second separator 4 and / or on the second coating 22 adjacent to the second separator 4. The receiving cavity 10 is used to contain electrolyte.
[0037] The battery cell provided in this embodiment has a certain electrolyte storage space in the receiving cavity 10 located at the first and second ends of the battery cell, so as to increase the electrolyte retention at the first and second ends of the battery cell, promote the migration of active ions at the first and second ends of the battery cell during charge and discharge cycles, and suppress the formation of lithium plating, spot-like black spots, local pitting, and battery cell thickening on the negative electrode sheets at the first and second ends of the battery cell, thereby reducing the thickness expansion rate of the battery and improving the battery's long cycle life and other performance characteristics.
[0038] Furthermore, such as Figure 1 As shown, a receiving cavity 10 is provided on the first coating 12 adjacent to the first diaphragm 3 and on the second coating 22 adjacent to the first diaphragm 3, so that a certain amount of electrolyte can be retained on both sides of the first diaphragm 3, further promoting the migration of active ions on both sides of the first diaphragm 3. A receiving cavity 10 is provided on the first coating 12 adjacent to the second diaphragm 4 and on the second coating 22 adjacent to the second diaphragm 4, so that a certain amount of electrolyte can be retained on both sides of the second diaphragm 4, further promoting the migration of active ions on both sides of the second diaphragm 4.
[0039] Furthermore, such as Figures 1-3As shown, the receiving cavity 10 located on the first coating 12 penetrates the first coating 12 along the second direction X, and the receiving cavity 10 located on the second coating 22 penetrates the second coating 22 along the second direction X. The second direction X is perpendicular to the first direction Z, so that the two ends of the receiving cavity 10 are connected to the two sides of the battery cell along the first direction Z, which facilitates the entry and exit of electrolyte from the outside of the battery cell into and out of the receiving cavity 10.
[0040] Furthermore, such as Figure 2 As shown, the height of the receiving cavity 10 along the first direction Z is H1, and the heights of the first coating 12 and the second coating 22 along the first direction Z are H, where H1 < H. This results in the presence of the first coating 12 between the first current collector 11 of the first electrode 1 with the receiving cavity 10 and the receiving cavity 10; and the presence of the second coating 22 between the second current collector 21 of the second electrode 2 with the receiving cavity 10 and the receiving cavity 10.
[0041] Furthermore, such as Figures 1-3 As shown, multiple receiving cavities 10 are provided on both the first coating 12 adjacent to the first diaphragm 3 and the second coating 22 adjacent to the first diaphragm 3, spaced apart along a third direction Y. Similarly, multiple receiving cavities 10 are provided on both the first coating 12 adjacent to the second diaphragm 4 and the second coating 22 adjacent to the second diaphragm 4, spaced apart along a third direction Y. The third direction Y is perpendicular to the first direction Z and forms an angle with the second direction X, thereby ensuring a more uniform distribution of electrolyte on both sides of the first diaphragm 3 and the second diaphragm 4. Preferably, in this embodiment, the third direction Y is perpendicular to the second direction X. The width of the receiving cavity 10 along the third direction Y is L1, and the width of both the first coating 12 and the second coating layer along the third direction Y is L. <L。
[0042] Furthermore, the total volume of the receiving cavity 10 on the first coating 12 adjacent to the first diaphragm 3 is V1, and the total volume of the first coating 12 on the first electrode 1 adjacent to the first diaphragm 3 is V, where 0 < V1 / V < 15%, to avoid the first coating 12 being too small and affecting its normal function. Similarly, the total volume of the receiving cavity 10 on the second coating 22 adjacent to the first diaphragm 3 is V1, and the total volume of the second coating 22 on the second electrode 2 adjacent to the first diaphragm 3 is V, where 0 < V1 / V < 15%, to avoid the second coating 22 being too small and affecting its normal function. Likewise, the total volume of the receiving cavity 10 on the first coating 12 adjacent to the second diaphragm 4 is V1, and the total volume of the first coating 12 on the first electrode 1 adjacent to the first diaphragm 3 is V, where 0 < V1 / V < 15%, to avoid the first coating 12 being too small and affecting its normal function. The total volume of the receiving cavity 10 on the second coating 22 adjacent to the second diaphragm 4 is V1, and the total volume of the second coating 22 on the second electrode 2 adjacent to the first diaphragm 3 is V, where 0 < V1 / V < 15%, to avoid the second coating 22 being too small and affecting its normal function. Preferably, in this embodiment, V1 / V is 7.5%.
[0043] Optionally, a plurality of first grooves are provided on both the first coating 12 and the second coating 22 adjacent to the first diaphragm 3, and the first grooves and the adjacent first diaphragm 3 form a receiving cavity 10. A plurality of second grooves are provided on both the first coating 12 and the second coating 22 adjacent to the second diaphragm 4, and the second grooves and the adjacent second diaphragm 4 form a receiving cavity 10.
[0044] Optionally, the outermost electrode at the first end of the battery cell is a first electrode 1. This first electrode 1 has a first coating 12 only on the side facing the first separator 3, and no first coating 12 on the side facing away from the first separator 3. Similarly, the outermost electrode at the second end of the battery cell is also a first electrode 1. This first electrode 1 has a first coating 12 only on the side facing the second separator 4, and no first coating 12 on the side facing away from the second separator 4. Each first electrode 1 between the outermost first electrode 1 at the first end of the battery cell and the outermost first electrode 1 at the second end of the battery cell has a first coating 12 on both sides. Each second electrode 2 between the outermost first electrode 1 at the first end of the battery cell and the outermost first electrode 1 at the second end of the battery cell has a second coating 22 on both sides.
[0045] Optionally, the battery cell may also include a third separator 5 among its multiple separators, with multiple third separators 5 spaced apart between the first separator 3 and the second separator 4.
[0046] Specifically, in this embodiment, the length L of the first coating 12 and the second coating 22 is 110 mm; the width W of the first coating 12 and the second coating 22 (which is also the length of the receiving cavity 10) is 60 mm; the height H of the first coating 12 and the second coating 22 is 40 μm; the width L1 of the receiving cavity 10 is 1 mm; the height H1 of the receiving cavity 10 is 20 μm; the number of receiving cavities 10 on the first coating 12 adjacent to the first diaphragm 3, the number of receiving cavities 10 on the second coating 22 adjacent to the first diaphragm 3, the number of receiving cavities 10 on the first coating 12 adjacent to the second diaphragm 4, and the number of receiving cavities 10 on the second coating 22 adjacent to the second diaphragm 4 are all N, where N is 11. In this embodiment, the first electrode 1 is a negative electrode, the second electrode 2 is a positive electrode, the number of positive electrodes is 24, the number of diaphragms is 50, and the number of negative electrodes is 25; thus, it can be calculated that: V = L·W·H = 264 mm 3 V1 = W·L1·H1·N = 19.8 mm 3 .
[0047] This embodiment also provides a battery, including the aforementioned battery cell, a casing, and an electrolyte. The battery cell is disposed within the casing, which is filled with the electrolyte. The battery in this embodiment is a pouch battery, and the casing is an aluminum-plastic film.
[0048] The above description is only a preferred embodiment of the present 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 the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.
Claims
1. A battery cell, characterized in that, It includes a first electrode (1), a diaphragm and a second electrode (2). Multiple first electrode (1), diaphragm and second electrode (2) are provided. The first electrode (1) and the second electrode (2) are alternately arranged along a first direction (Z). One of the first electrode (1) and the second electrode (2) is a positive electrode and the other is a negative electrode. The diaphragm is sandwiched between the first electrode (1) and the second electrode (2). The first electrode (1) includes a first current collector (11) and a first coating (12) coated on the side of the first current collector (11). The first coating (12) is sandwiched between the first current collector (11) and the adjacent diaphragm. The second electrode (2) includes a second current collector (21) and a second coating (22) coated on the side of the second current collector (21). The second coating (22) is sandwiched between the second current collector (21) and the adjacent diaphragm. The diaphragm closest to the first end of the battery cell is the first diaphragm (3), and the diaphragm closest to the second end of the battery cell is the second diaphragm (4). The first diaphragm (3) and the second diaphragm (4) are both sandwiched between the first electrode (1) and the second electrode (2). A receiving cavity (10) is provided on a first coating (12) adjacent to the first diaphragm (3) and / or on a second coating (22) adjacent to the first diaphragm (3), and the receiving cavity (10) is provided on a first coating (12) adjacent to the second diaphragm (4) and / or on a second coating (22) adjacent to the second diaphragm (4), and the receiving cavity (10) is used to contain electrolyte.
2. The battery cell according to claim 1, characterized in that, The receiving cavity (10) is provided on the first coating (12) adjacent to the first diaphragm (3) and on the second coating (22) adjacent to the first diaphragm (3), and the receiving cavity (10) is provided on the first coating (12) adjacent to the second diaphragm (4) and on the second coating (22) adjacent to the second diaphragm (4).
3. The battery cell according to claim 2, characterized in that, The receiving cavity (10) located on the first coating (12) penetrates the first coating (12) along the second direction (X), and the receiving cavity (10) located on the second coating (22) penetrates the second coating (22) along the second direction (X), the second direction (X) being perpendicular to the first direction (Z).
4. The battery cell according to claim 3, characterized in that, The height of the receiving cavity (10) along the first direction (Z) is H1, and the height of the first coating (12) and the second coating (22) along the first direction (Z) is H, where H1 < H.
5. The battery cell according to claim 3 or 4, characterized in that, Multiple receiving cavities (10) are provided on the first coating (12) adjacent to the first diaphragm (3) and on the second coating (22) adjacent to the first diaphragm (3) at intervals along a third direction (Y). Multiple receiving cavities (10) are provided on the first coating (12) adjacent to the second diaphragm (4) and on the second coating (22) adjacent to the second diaphragm (4) at intervals along the third direction (Y). The third direction (Y) is perpendicular to the first direction (Z) and forms an angle with the second direction (X).
6. The battery cell according to claim 5, characterized in that, The third direction (Y) is perpendicular to the second direction (X).
7. The battery cell according to claim 2, characterized in that, The total volume of the receiving cavity (10) on the first coating (12) adjacent to the first diaphragm (3) is V1, and the total volume of the first coating (12) on the first electrode (1) adjacent to the first diaphragm (3) is V; the total volume of the receiving cavity (10) on the second coating (22) adjacent to the first diaphragm (3) is V1, and the total volume of the second coating (22) on the second electrode (2) adjacent to the first diaphragm (3) is V; the total volume of the receiving cavity (10) on the first coating (12) adjacent to the second diaphragm (4) is V1, and the total volume of the first coating (12) on the first electrode (1) adjacent to the first diaphragm (3) is V; the total volume of the receiving cavity (10) on the second coating (22) adjacent to the second diaphragm (4) is V1, and the total volume of the second coating (22) on the second electrode (2) adjacent to the first diaphragm (3) is V; 0 < V1 / V < 15%.
8. The battery cell according to claim 7, characterized in that, The V1 / V ratio is 7.5%.
9. The battery cell according to claim 2, characterized in that, The first coating (12) and the second coating (22) adjacent to the first diaphragm (3) are each provided with a plurality of first grooves, and the first grooves and the adjacent first diaphragm (3) surround to form the receiving cavity (10). The first coating (12) and the second coating (22) adjacent to the second diaphragm (4) are each provided with a plurality of second grooves, and the second grooves and the adjacent second diaphragm (4) surround to form the receiving cavity (10).
10. A battery, characterized in that, The battery cell according to any one of claims 1-9 further includes a housing and an electrolyte, wherein the battery cell is disposed within the housing and the housing is filled with the electrolyte.