Battery cell and battery
By designing a structure in which the electrode ear and the tail fixture do not overlap in the thickness direction in the battery cell, the problem of low energy density of the battery cell in the prior art is solved, and the energy density of the battery cell is improved.
Patent Information
- Application Number
- CN202422076779.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-08-26
AI Technical Summary
In the prior art, since the pole ear and the tail fixing member overlap in the thickness direction of the battery cell, the energy density of the battery cell is low.
The structure in which the electrode ear and the ending fixture do not overlap in the thickness direction of the battery cell is designed. Through the special design of the electrode ear and the position optimization of the ending fixture, the electrode sheet is fixed without increasing the cell thickness.
The energy density of the battery cell is improved without changing the size of the battery cell or the position of the pole ear. The design of the pole ear and the tail fixture effectively avoids the reduction of the energy density of the battery cell and increases the energy density of the battery cell.
Smart Images
Figure CN223245852U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a battery core and a battery. Background Art
[0002] In the related art, the positive and negative electrodes can be formed into a battery cell through a winding process or a lamination process. After the positive and negative electrodes are wound to form a battery cell, the tails of the positive and negative electrodes need to be fixed with a finishing glue. The thickness of the finishing glue is generally greater than 20u, and the area of the winding core plane accounts for not less than 50%. Among them, since the position of the tabs welded on the electrode overlaps with the hot melt finishing glue in the thickness direction, this will increase the thickness of the winding core, resulting in a lower energy density of the battery cell. Utility Model Content
[0003] The present invention aims to solve at least one of the technical problems in the prior art. To this end, the present invention provides a battery cell having a high energy density.
[0004] The utility model also provides a battery.
[0005] The battery cell according to the first embodiment of the present invention includes:
[0006] A main body is formed by winding the pole piece, and the main body includes a first surface;
[0007] A tail fixing piece is attached to the first surface, and the tail fixing piece is used to fix the pole piece;
[0008] The pole tab is connected to the pole piece, and along the thickness direction of the main body, the projection of the pole tab and the projection of the tail fixing piece do not overlap with each other.
[0009] The battery cell according to the embodiment of the present invention has at least the following beneficial effects: the tail fixture can be attached to the first surface, thereby being able to fix the electrode. In the prior art, along the thickness direction of the main body, the position of the tail fixture and the position of the electrode tab will overlap, which will result in a low energy density of the battery cell. However, in the present application, along the thickness direction of the main body, the projection of the electrode tab and the projection of the tail fixture do not overlap with each other, which will not increase the thickness of the main body, resulting in a low energy density of the battery cell. In addition, the battery cell of the present application can have a higher energy density without changing its own size or the position of the electrode tab. Specifically, the battery cell can have a higher energy density.
[0010] According to some embodiments of the battery cell of the present invention, the tab includes a first portion, a second portion, and a third portion, the first portion and the third portion are respectively connected to two sides of the second portion, and the first portion and the third portion are staggered along the length direction of the first portion.
[0011] According to some embodiments of the battery cell of the present invention, a distance between a center line of the first portion in the length direction and a center line of the third portion in the length direction is A, and A is ≥ 1 mm.
[0012] According to the battery cell of some embodiments of the present invention, the width of the first portion is smaller than the width of the third portion, and the third portion is connected to the pole piece.
[0013] According to some embodiments of the battery cell of the present invention, the third portion is connected to the pole piece via a welding point, the width of the welding point is B, the width of the third portion is C, and B / C ≥ 0.65.
[0014] According to some embodiments of the present invention, the battery cell further includes tab glue, and the tab glue is attached to the second part.
[0015] According to the battery cell of some embodiments of the present invention, the two ends of the tab glue protrude relative to the second portion along the length direction of the second portion by a dimension D, and 1mm≤D≤3mm.
[0016] According to the battery cell of some embodiments of the present invention, the two ends of the tab glue protrude relative to the second portion along the width direction of the second portion by a dimension E, and 0.4 mm ≤ E ≤ 2 mm.
[0017] According to the battery cell of some embodiments of the present invention, the area of the tail fixture is F, the area of the first surface is G, and F / G≥1 / 2.
[0018] The battery according to the second embodiment of the present invention includes the battery cell described in any one of the first embodiment.
[0019] The battery according to the embodiment of the present invention has at least the following beneficial effects: the tail fixture can be attached to the first surface, thereby being able to fix the pole piece. In the prior art, along the thickness direction of the main body, the position of the tail fixture and the position of the pole ear will overlap, which will result in a low energy density of the battery cell. In the present application, along the thickness direction of the main body, the projection of the pole ear and the projection of the tail fixture do not overlap with each other, which will not increase the thickness of the main body, resulting in a low energy density of the battery cell. In addition, the battery cell of the present application can have a higher energy density without changing its own size or the position of the pole ear. Specifically, the battery cell can have a higher energy density. Furthermore, the energy density of the battery having this battery cell is also higher.
[0020] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:
[0022] Figure 1 Schematic diagram of battery cells according to some embodiments of the present invention;
[0023] Figure 2 Schematic diagram of a battery cell in the prior art;
[0024] Figure 3 Schematic diagram of tabs in a battery cell in some embodiments of the present utility model;
[0025] Figure 4 Schematic diagram of tabs and tab glue in battery cells of some embodiments of the present invention;
[0026] Figure 5 Schematic diagram of the tabs and pole pieces in the battery cell of some embodiments of the present invention.
[0027] Reference numerals:
[0028] Battery cell 100 , main body 200 , first surface 210 , pole piece 300 , tail fixing member 400 , pole tab 500 , first portion 510 , second portion 520 , third portion 530 , welding point 600 , pole tab glue 700 . DETAILED DESCRIPTION
[0029] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.
[0030] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.
[0031] In the description of this utility model, "several" means more than one, "plurality" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of the terms "first" and "second" is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.
[0032] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.
[0033] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
[0034] In the related art, the positive electrode sheet and the negative electrode sheet can be formed into a battery cell 100 through a winding process or a lamination process. After the positive electrode sheet and the negative electrode sheet are wound to form the battery cell 100, the tails of the positive electrode sheet and the negative electrode sheet need to be fixed by a finishing glue. The thickness of the finishing glue is generally greater than 20u, and the area of the core plane accounts for not less than 50%. Among them, since the position of the tab 500 welded on the electrode sheet 300 overlaps with the hot melt finishing glue in the thickness direction, this will increase the thickness of the core, resulting in a lower energy density of the battery cell 100. To this end, the present application proposes a battery cell 100.
[0035] Please refer to Figure 1In some embodiments, the battery cell 100 includes: a main body 200, a terminal fixture 400, and a tab 500. The main body 200 is formed by winding the electrode sheet 300. Specifically, the main body 200 can be formed by stacking the positive electrode sheet, the separator, and the negative electrode sheet and then winding them together to form the main body 200. The shape of the main body 200 can be approximately a rectangular parallelepiped or a cube. The main body 200 includes a first surface 210 and a second surface arranged opposite to each other, and a third surface and a fourth surface arranged opposite to each other. The first surface 210 and the second surface can be flat, and the third surface and the fourth surface can be curved. The two ends of the first surface 210 are connected to the third surface and the fourth surface, respectively, and the two ends of the second surface are connected to the third surface and the fourth surface, respectively. It is conceivable that the main body 200 is formed by stacking and winding the positive electrode sheet and the negative electrode sheet. Therefore, the same end of the positive electrode sheet or the negative electrode sheet can serve as the starting point of the winding, and the other end of the positive electrode sheet or the negative electrode sheet can serve as the end point of the winding. After the positive and negative electrode sheets are wound, their ends at the winding end may warp. To prevent this warping and causing the main body 200 to loosen, a finishing fixture 400 is required. Specifically, the finishing fixture 400 is attached to the first surface 210 and is used to secure the electrode sheet 300. The finishing fixture 400 can be hot melt adhesive or other adhesive tape. The finishing fixture 400 can be a square piece of adhesive tape. After being attached to the first surface 210, the square piece of adhesive tape can secure the end of the outermost electrode sheet 300 to the surface of the next outermost electrode sheet 300. The tabs 500 are connected to the electrode sheet 300. The tabs 500 include a positive tab 500 and a negative tab 500. The electrode sheet 300 includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet is connected to the positive tab 500, and the negative electrode sheet is connected to the negative electrode sheet. Along the thickness direction of the main body 200, the projection of the tab 500 and the projection of the finishing fixture 400 do not overlap. Specifically, the tail fixing member 400 can be attached to the first surface 210, so as to fix the pole piece 300. In the prior art, please refer to Figure 2 , along the thickness direction of the main body 200, the position of the end fixing member 400 and the position of the tab 500 will overlap, which will result in a lower energy density of the battery cell 100. In this application, please refer to Figure 1 Since the projections of the tabs 500 and the projections of the final fixture 400 do not overlap along the thickness direction of the main body 200, the thickness of the main body 200 will not be increased, which would result in a lower energy density of the battery cell 100. Furthermore, the battery cell 100 of the present application can have a higher energy density without changing its own size or the position of the tabs 500. Specifically, the battery cell 100 can have a higher energy density.
[0036] Further, the specific structure of the tab 500 is described below, please refer to Figure 1 and Figure 3In some embodiments, the tab 500 includes a first portion 510, a second portion 520, and a third portion 530. The first portion 510, the second portion 520, and the third portion 530 can be an integral structure, cut from the same metal material and the same thickness, such as copper or aluminum. The first portion 510 and the third portion 530 are respectively connected to both sides of the second portion 520, and the first portion 510 and the third portion 530 are staggered along the length direction of the first portion 510. Specifically, the length direction of the second portion 520 is perpendicular to the length direction of the first portion 510 and perpendicular to the length direction of the third portion 530. The length direction of the first portion 510 is parallel to the length direction of the third portion 530. The staggered arrangement of the first portion 510 and the third portion 530 along the length direction of the first portion 510 specifically means that the first portion 510 is parallel to the length direction of the third portion 530 in its own length direction but not in the same line. Among them, the tab 500 has two, the first part 510, the second part 520 and the third part 530. On the one hand, the specific structure can prevent the distance between the two tabs 500 from being too large, so that the battery cell 100 can be adapted to more electronic devices; on the other hand, this design can make the tab 500 staggered with the tail fixing part 400 in the thickness direction of the main body 200, thereby effectively avoiding the low capacity density of the battery cell 100.
[0037] For further information, please refer to Figure 3 In some embodiments, the distance between the centerline of the first portion 510 in the longitudinal direction and the centerline of the third portion 530 in the longitudinal direction is A, where A ≥ 1 mm. The centerline of the first portion 510 in the longitudinal direction specifically refers to the centerline of the first portion 510 in the longitudinal direction dividing the first portion 510 into two halves of equal area in the width direction. The centerline of the third portion 530 in the longitudinal direction specifically refers to the centerline of the third portion 530 in the longitudinal direction dividing the third portion 530 into two halves of equal area in the width direction. The distance between the centerline of the first portion 510 in the longitudinal direction and the centerline of the third portion 530 in the longitudinal direction can be 1 mm, 2 mm, 3 mm, or 4 mm. In some cases, the distance between the two first parts 510 is a fixed value. When the distance between the center line of the first part 510 in the length direction and the center line of the third part 530 in the length direction is less than 1 mm, since the distance between the center line of the first part 510 in the length direction and the center line of the third part 530 in the length direction is too close, this will cause the distance between the two third parts 530 to be relatively close, thereby reducing the area of the tail fixing 400 and making the effect of the tail fixing 400 in fixing the pole piece 300 worse.
[0038] For further information, please refer to Figure 5In some embodiments, the width of the first portion 510 is smaller than the width of the third portion 530, and the third portion 530 is connected to the electrode 300. The third portion 530 may be connected to the electrode 300 by welding the third portion 530 to the electrode 300. The third portion 530 is connected to the electrode 300, and the first portion 510 can be connected to an electronic device, thereby enabling charging and discharging of the battery cell 100 with the outside world. The width of the third portion 530 is greater than the width of the first portion 510, which can increase the area for current collection, facilitating current diversion and reducing the temperature of the battery cell 100.
[0039] For further information, please refer to Figure 5 In some embodiments, the third portion 530 is connected to the pole piece 300 via a weld 600. The width of the weld 600 is B, the width of the third portion 530 is C, and B / C ≥ 0.65. Specifically, after the third portion 530 is welded to the pole piece 300, a weld 600 is formed at the connection between the third portion 530 and the pole piece 300. The width of the weld is not less than 65% of the width of the third portion 530, which can increase the stability of the connection between the third portion 530 and the pole piece 300 and make the connection between the third portion 530 and the pole piece 300 more reliable.
[0040] For further information, please refer to Figure 4 In some embodiments, the battery cell 100 further includes a tab glue 700, which is attached to the second part 520. Specifically, after the tab glue 700 is attached to the second part 520, the tab glue 700 has the following functions: reinforcing the tab 500, the tab glue 700 tightly fits the tab 500 to the battery shell, increases its rigidity and strength, and prevents vibration and excessive stress from affecting the tab 500. Insulation protection prevents a short circuit between the metal strip on the tab 500 and the aluminum-plastic film, ensures the normal operation of the battery, and avoids the risk of a short circuit caused by contact between the second part 520 and the pole piece 300. Resistance to electrolyte corrosion, the tab glue 700 has the characteristics of high temperature resistance and electrolyte corrosion resistance, protecting the tab 500 from electrolyte erosion.
[0041] For further information, please refer to Figure 4In some embodiments, the two ends of the tab glue 700 protrude relative to the second portion 520 along the length direction of the second portion 520 by a dimension D, where 1mm≤D≤3mm. Specifically, the two ends of the tab glue 700 protrude relative to the second portion 520 along the length direction of the second portion 520, which means that the length of the tab glue 700 is greater than the length of the second portion 520, and one end of the tab glue 700 protrudes beyond one end of the second portion 520, while the other end of the tab glue 700 also protrudes beyond the other end of the second portion 520. In other words, the tab glue 700 covers the second portion 520 along the length direction of the second portion 520. The protrusions of the two ends of the tab glue 700 relative to the second portion 520 along the length direction of the second portion 520 can be 1mm, 2mm, or 3mm. This effectively ensures that the tab glue 700 completely covers the second portion 520 along the length direction of the second portion 520, preventing the second portion 520 from leaking out and causing the risk of a short circuit.
[0042] For further information, please refer to Figure 4 In some embodiments, the two ends of the tab glue 700 protrude relative to the second portion 520 along the width direction of the second portion 520 by a dimension E, where 0.4 mm ≤ E ≤ 2 mm. Specifically, the two ends of the tab glue 700 protrude relative to the second portion 520 along the width direction of the second portion 520, specifically referring to the fact that the width of the tab glue 700 is greater than the width of the second portion 520, one end of the tab glue 700 protrudes beyond one end of the second portion 520, and the other end of the tab glue 700 also protrudes beyond the other end of the second portion 520. In other words, the tab glue 700 covers the second portion 520 along the width direction of the second portion 520. The protrusion of the two ends of the tab glue 700 relative to the second portion 520 along the width direction of the second portion 520 can be 0.4 mm, 1 mm, or 2 mm. This effectively ensures that the tab glue 700 completely covers the second portion 520 along the width direction of the second portion 520, preventing the second portion 520 from leaking out and causing the risk of a short circuit.
[0043] Furthermore, in some embodiments, the area of the final fixture 400 is F, the area of the first surface 210 is G, and F / G ≥ 1 / 2. Specifically, the area of the final fixture 400 can be 1 / 2 or 2 / 3 of the area of the first surface 210. If the area of the final fixture 400 accounts for too little of the area of the first surface 210, the final fixture 400 may not provide a good fixation effect, and the battery may fail easily when dropped.
[0044] Furthermore, in some embodiments, the thickness of the end fixture 400 is greater than 20 μm. A thicker end fixture 400 can provide a larger bonding area and stronger cohesive force, thereby improving the overall bonding strength. A thicker end fixture 400 can often better resist the effects of external environmental factors (such as temperature changes, humidity, chemical corrosion, etc.) on the bonding interface, thereby extending the service life of the adhesive. Furthermore, a thicker end fixture 400 can better disperse stress when subjected to external forces, reducing the risk of damage to the bonding interface due to stress concentration.
[0045] In some embodiments, the battery includes the battery cell 100 of any one of the above embodiments. Specifically, the tail fixture 400 can be attached to the first surface 210, so as to fix the pole piece 300. In the prior art, along the thickness direction of the main body 200, the position of the tail fixture 400 and the position of the pole tab 500 will overlap, which will result in a lower energy density of the battery cell 100. However, in the present application, along the thickness direction of the main body 200, the projection of the pole tab 500 and the projection of the tail fixture 400 do not overlap with each other, which will not increase the thickness of the main body 200, resulting in a lower energy density of the battery cell 100. Specifically, the battery cell 100 can have a higher energy density. Furthermore, the energy density of the battery having the battery cell 100 is also higher.
[0046] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. In addition, the embodiments of the present invention and the features of the embodiments can be combined with each other unless there is a conflict.
Claims
1. A battery cell, characterized in that: include: A main body is formed by winding the pole piece, and the main body includes a first surface; A tail fixing piece is attached to the first surface, and the tail fixing piece is used to fix the pole piece; The pole tab is connected to the pole piece, and along the thickness direction of the main body, the projection of the pole tab and the projection of the tail fixing piece do not overlap with each other.
2. The battery cell according to claim 1, characterized in that The tab includes a first portion, a second portion, and a third portion. The first portion and the third portion are respectively connected to two sides of the second portion. Along the length direction of the first portion, the first portion and the third portion are staggered.
3. The battery cell according to claim 2, characterized in that A distance between a center line of the first portion in the length direction and a center line of the third portion in the length direction is A, and A is ≥ 1 mm.
4. The battery cell according to claim 2, characterized in that The width of the first portion is smaller than the width of the third portion, and the third portion is connected to the pole piece.
5. The battery cell according to claim 4, characterized in that: The third portion is connected to the pole piece via a welding point, the width of the welding point is B, the width of the third portion is C, and B / C is ≥ 0.
65.
6. The battery cell according to claim 2, characterized in that The battery cell further includes tab glue, and the tab glue is attached to the second part.
7. The battery cell according to claim 6, characterized in that The two ends of the tab glue protrude relative to the second portion along the length direction of the second portion by a dimension D, 1 mm ≤ D ≤ 3 mm.
8. The battery cell according to claim 6, characterized in that: The two ends of the tab glue protrude relative to the second portion along the width direction of the second portion by a dimension E, where 0.4 mm ≤ E ≤ 2 mm.
9. The battery cell according to claim 1, characterized in that The area of the finishing fixture is F, the area of the first surface is G, and F / G≥1 / 2.
10. A battery, characterized in that The invention comprises the battery cell according to any one of claims 1 to 9.