Battery cell and battery

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell and a battery, the battery cell comprises a battery cell main body, a positive tab, a negative tab and an insulating plate; the positive electrode lug and the negative electrode lug are respectively connected with the battery cell main body and are arranged on the same side of the battery cell main body, the positive electrode lug and the negative electrode lug extend along the length direction of the battery cell main body, and the insulating plate is connected between the positive electrode lug and the negative electrode lug; the insulating plate is used for insulating and separating the positive tab and the negative tab in the thickness direction of the battery cell main body; according to the scheme, the volume of the battery cell can be reduced, so that the energy density of the battery is improved; meanwhile, according to the scheme, the width of the positive tab and the width of the negative tab are relatively large, so that the resistance values of the two tabs are reduced, the effective power of the battery is favorably increased, the use requirement of the battery on large current is met, the heat dissipation performance of the battery is favorably improved, the expansion rate of the battery is slowed down, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery cell and a battery. Background Art

[0002] Currently, one or more battery cells are installed inside the battery. The current battery cell mainly includes a battery cell body and an outer membrane. The outer membrane is used to wrap the battery cell body to seal the battery cell body and prevent the battery cell body from contacting the battery shell and short-circuiting. The battery cell body can be a laminated structure or a wound core structure. The battery cell body is mainly composed of structural parts such as positive electrode sheets, negative electrode sheets, and diaphragms. The diaphragm is arranged between the positive electrode sheets and the negative electrode sheets to insulate and separate the positive and negative electrode sheets. In addition, the battery cell also includes a positive electrode ear connected to the positive electrode sheet and a negative electrode ear connected to the negative electrode sheet. Both the positive electrode ear and the negative electrode ear are exposed outward relative to the outer membrane. There are mainly two types of battery cells at present:

[0003] The positive and negative tabs on the first type of battery cell are arranged on opposite sides. Since there is no need to consider the easy contact and short circuit between the positive and negative tabs, the width of both tabs can be designed to be larger to meet the requirements of high current use. However, since the positive and negative tabs are arranged on different sides, the battery volume will be larger, resulting in a lower energy density of the battery.

[0004] The positive and negative tabs on the second type of battery cell are arranged on the same side to reduce the volume of the battery cell. However, since the positive and negative tabs arranged on the same side need to consider the problem of easy contact and short circuit between the two tabs, there is a large distance between the positive and negative tabs in the width direction to avoid short circuit between the two tabs. This design will force the width of the positive and negative tabs to be designed to be narrower. The greater the resistance of the narrower tab, the smaller the corresponding effective power will be, and the heat generation at the tab will also increase, affecting the performance of the battery and failing to meet the requirements of high current use.

[0005] Therefore, there is a need to improve the existing technology.

[0006] The above information is presented as background information only to assist with an understanding of the present disclosure and is not a determination or admission that any of the above may be applicable as prior art with respect to the present disclosure. Utility Model Content

[0007] The utility model provides a battery cell and a battery, which mainly solve the technical problem of how to reduce the volume of the battery cell to improve the energy density and reduce the resistance of the tab at the same time.

[0008] To achieve the above objectives, the present invention provides the following technical solutions:

[0009] A battery cell, comprising a battery cell body, a positive electrode tab, a negative electrode tab and an insulating plate;

[0010] The positive electrode tab and the negative electrode tab are respectively connected to the battery cell body and are arranged on the same side of the battery cell body, and the positive electrode tab and the negative electrode tab both extend along the length direction of the battery cell body. The insulating plate is connected between the positive electrode tab and the negative electrode tab, and the insulating plate is used to insulate and separate the positive electrode tab and the negative electrode tab in the thickness direction of the battery cell body.

[0011] In one of the technical solutions, the battery cell body is a wound structure with a central hole in the middle, the insulating plate is thermally conductive, and the insulating plate extends into the central hole and contacts the hole wall of the central hole.

[0012] In one of the technical solutions, the battery cell body wraps around the outer wall of the insulating plate when being wound.

[0013] In one of the technical solutions, the outer edges of the insulating plate that contact the hole wall of the central hole are all provided with rounded corner structures.

[0014] In one of the technical solutions, the thickness of the insulating plate is 0.5-2 mm.

[0015] In one technical solution, after the battery cell body is wound, a first arcuate surface and a second arcuate surface are formed on the outer wall thereof, and the positive electrode tab and the negative electrode tab both extend from the first arcuate surface to the second arcuate surface.

[0016] In one technical solution, the width of the central hole is equal to the width of the insulating plate, and the width of the positive electrode tab and the width of the negative electrode tab are both less than or equal to the width of the insulating plate.

[0017] In one of the technical solutions, the insulating plate includes a first end and a second end that are arranged opposite to each other, the first end is used to separate the positive electrode ear and the negative electrode ear, and the second end extends into the middle hole and does not exceed the outer end surface of the battery body facing away from the positive electrode ear or the negative electrode ear.

[0018] In one of the technical solutions, a plurality of holes for accommodating electrolyte are provided on the insulating plate.

[0019] In one technical solution, a plurality of first current collectors and a plurality of second current collectors are extended from the battery cell body, wherein the polarity of the first current collectors is opposite to that of the second current collectors, the plurality of first current collectors are connected to the positive electrode tab and are all located on the side of the positive electrode tab facing away from the insulating plate, and the plurality of second current collectors are connected to the negative electrode tab and are all located on the side of the negative electrode tab facing away from the insulating plate;

[0020] The battery cell also includes an outer film, which wraps the entire battery cell body, multiple first current collectors and multiple second current collectors, and the outer film wraps part of the insulating plate, part of the positive electrode ear and part of the negative electrode ear, so that the insulating plate, the negative electrode ear and the positive electrode ear are all exposed outward relative to the outer film; the gap between the outer film and the insulating plate, the gap between the outer film and the positive electrode ear, and the gap between the outer film and the negative electrode ear are all filled with hot melt adhesive.

[0021] The present application also includes a battery, comprising the battery cell described in any of the above technical solutions.

[0022] Compared with the prior art, the battery cell provided by the present invention has at least the following beneficial effects:

[0023] This solution reduces the volume of the battery cell by designing the positive and negative tabs on the same side of the battery cell body, which is beneficial to improving the energy density of the battery. At the same time, this solution also designs both the positive and negative tabs to extend along the length of the battery cell body, making the width of the positive and negative tabs larger, thereby reducing the resistance of the two tabs, thereby increasing the effective power of the battery to meet the battery's requirements for high current use. It is also beneficial to improve the battery's heat dissipation performance, slowing the rate of battery expansion and extending the battery's service life. In addition, to prevent the wider positive and negative tabs from short-circuiting due to contact with each other, this solution provides an insulating plate between the positive and negative tabs to insulate and separate the positive and negative tabs in the thickness direction of the battery cell body, thereby reducing the risk of short-circuiting the battery cell and improving the safety and reliability of the battery over long periods of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of a battery cell provided in an embodiment of the present application at a first angle;

[0026] Figure 2 for Figure 1 A partial enlarged view of point A in the middle;

[0027] Figure 3 A schematic diagram of a battery cell provided in an embodiment of the present application at a second angle;

[0028] Figure 4 for Figure 3 A partial enlarged view of point B in the middle;

[0029] Figure 5 A schematic diagram of a battery cell provided in an embodiment of the present application at a third angle;

[0030] Figure 6 A schematic diagram of an insulating plate provided in an embodiment of the present application when holes are provided;

[0031] Figure 7 for Figure 1 Schematic diagram of the structure of the battery cell after the outer membrane is set;

[0032] Figure 8 for Figure 7 The internal structure diagram of the battery cell shown;

[0033] Figure 9 for Figure 8 A partial enlarged view of point C in the middle.

[0034] Reference numerals:

[0035] 21. Battery cell body; 211. Middle hole; 212. Outer end face; 213. First curved surface; 214. Second curved surface; 22. Positive electrode ear; 23. Negative electrode ear; 24. Insulating plate; 241. Rounded corner structure; 242. First end; 243. Second end; 244. Hole position; 25. Outer film; 26. First current collector; 27. Second current collector. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0037] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0038] It should be understood that the terms, "upper", "lower", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0039] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0041] Please also refer to Figure 1 and Figure 3 The embodiment of the present invention provides a battery cell, which mainly includes a battery cell body 21, a positive electrode ear 22, a negative electrode ear 23 and an insulating plate 24, wherein the battery cell body 21 is the existing technology, and the battery cell body 21 includes a positive electrode sheet, a negative electrode sheet and a separator for insulating and separating the positive electrode sheet and the negative electrode sheet. The battery cell body 21 can be a winding type structure, and the battery cell body 21 can also be a stacked structure; wherein the positive electrode ear 22 is connected to the positive electrode sheet in the battery cell body 21, and the negative electrode ear 23 is connected to the negative electrode sheet in the battery cell body 21, and the positive electrode ear 22 and the negative electrode ear 2 3 is connected to the same side of the battery cell body 21 to reduce the overall volume of the battery cell, thereby facilitating an increase in the battery's energy density. Furthermore, both the positive tab 22 and the negative tab 23 extend along the length of the battery cell body 21, increasing the width of the positive tab 22 and the width of the negative tab 23, thereby reducing the resistance of the positive tab 22 and the negative tab 23. This in turn helps increase the effective power of the battery to meet the battery's high current requirements. It also helps improve the battery's heat dissipation performance, slowing the rate of battery expansion and extending the battery's service life. Furthermore, to prevent the wider positive tab 22 and negative tab 23 from short-circuiting due to contact, this solution provides an insulating plate 24 between the positive tab 22 and the negative tab 23. The insulating plate 24 insulates and separates the positive tab 22 and the negative tab 23 along the thickness of the battery cell body 21, thereby reducing the risk of short-circuiting and improving the safety and reliability of the battery over long periods of use.

[0042] Please also refer to Figure 2 、 Figure 4 、 Figure 5 and Figure 8The battery cell body 21 preferably has a wound structure with a central hole 211. The insulating plate 24 is thermally conductive and extends into the central hole 211, contacting the wall of the central hole 211. This design allows the insulating plate 24 to not only dissipate heat from the positive and negative tabs 22 and 23 but also dissipate heat accumulated within the battery cell body 21, thereby significantly improving the heat dissipation performance of the battery cell and enabling the battery cell to accommodate higher current requirements. The insulating plate 24 can be made of silicon nitride or silicon carbide, both of which have excellent thermal conductivity.

[0043] Please also refer to Figure 1 and Figure 3 After the battery cell body 21 is wound, a first arc-shaped surface 213 and a second arc-shaped surface 214 are formed on the outer wall. The length direction of the above-mentioned battery cell body 21 can be understood as the direction in which the first arc-shaped surface 213 points to the second arc-shaped surface 214, that is, the positive electrode ear 22 and the negative electrode ear 23 can be understood as extending from the first arc-shaped surface 213 to the second arc-shaped surface 214.

[0044] In this embodiment, please refer to Figure 5 When the battery cell body 21 is wound, it wraps around the outer wall of the insulating plate 24. At this time, the width W4 of the middle hole 211 is equivalent to the width W1 of the insulating plate 24. At this time, the outer wall of the insulating plate 24 can be in close contact with the hole wall of the middle hole 211, so as to improve the thermal conductivity of the insulating plate 24 to the battery cell body 21, thereby improving the heat dissipation efficiency of the battery cell.

[0045] In this embodiment, the thickness of the insulating plate 24 is preferably 0.5-2 mm. This thickness of the insulating plate 24 not only ensures excellent thermal conductivity, but also, when the battery cell body 21 is subsequently hot-pressed, it can also prevent the electrode tabs at the corners of the inner circle of the battery cell body 21 from being excessively compressed, broken, or even bent and broken. In conventional wound-type battery cell bodies 21, the inner circle of the inner circle is wound with several layers of separator to prevent the inner circle electrode tabs from bending and breaking. With a certain thickness of the insulating plate 24, the design of multiple layers of separator can be eliminated, thereby freeing up more space for the positive and negative electrode tabs, thereby increasing the battery cell's power and energy density.

[0046] Please also refer to Figure 2 and Figure 4 The outer edges of the insulating plate 24 that contact the wall of the middle hole 211 are all provided with a rounded structure 241. This rounded structure 241 can further improve the phenomenon that the pole pieces at the corners of the inner circle of the battery body 21 are excessively pressed and broken, thereby further improving the reliability of the battery body 21 after being wound on the insulating plate 24.

[0047] Please also refer to Figure 5 and Figure 8 The insulating plate 24 includes a first end 242 and a second end 243 that are arranged opposite to each other, wherein the first end 242 is used to separate the positive electrode ear 22 and the negative electrode ear 23, and the second end 243 extends into the middle hole 211 and does not exceed the outer end surface 212 of the battery body 21 facing away from the positive electrode ear 22 or the negative electrode ear 23, thereby ensuring that the volume of the battery cell is small and that the battery cell has a high energy density. Preferably, the second end 243 of the insulating plate 24 is flush with the battery body 21 at the outer end surface 212, so as to ensure that the volume of the battery cell is small while still being able to reliably provide for the entire battery body 21 to be wound, thereby reducing the risk of the insulating plate 24 being separated from the middle hole 211 inside the battery body 21, and also ensuring that the entire battery body 21 can be supported by the internal insulating plate 24, reducing the risk of the battery body 21 being deformed by force, and improving the reliability of the battery cell structure.

[0048] See also Figure 5 , the width W2 of the negative electrode ear 23 is less than or equal to the width W1 of the insulating plate 24, please refer to Figure 7 The width W3 of the positive electrode ear 22 is less than or equal to the width W1 of the insulating plate 24. The ends of the positive electrode ear 22 and the negative electrode ear 23 in the width direction are preferably 2 mm away from the edge of the insulating plate 24 in the width direction. The width of the positive electrode ear 22 and the negative electrode ear 23 can be designed to be narrower while meeting the preset current overcurrent requirements. In addition, the positive electrode ear 22 and the negative electrode ear 23 can be designed as a hollow structure to reduce the weight of the battery cell, thereby improving the energy density of the battery.

[0049] See also Figure 6 A plurality of holes 244 may be provided on the insulating plate 24 . The holes 244 may pass through the insulating plate 24 or may not pass through the insulating plate 24 . The holes 244 may be used to accommodate electrolyte, thereby increasing the liquid retention of the battery cell and thus helping to increase the service life of the battery.

[0050] Please also refer to Figure 1 、 Figure 3 and Figures 7 to 9The battery cell of this embodiment further includes an outer film 25, preferably an existing aluminum-plastic film. The outer film 25 encloses the entire battery cell body 21, sealing the battery cell body 21 and preventing contact between the battery cell body 21 and the battery casing, which could cause a short circuit. Specifically, the outer film 25 encloses a portion of the insulating plate 24, a portion of the positive tab 22, and a portion of the negative tab 23, such that the insulating plate 24, the positive tab 22, and the negative tab 23 are all exposed relative to the outer film 25. At this point, the battery cell body 21 can be charged or discharged by conducting current between the positive tab 22 and the negative tab 23. Specifically, a plurality of positive electrode sheets and a plurality of negative electrode sheets are usually provided in the battery cell body 21. Correspondingly, a plurality of first current collectors 26 and a plurality of second current collectors 27 are led out from the battery cell body 21. The polarity of the first current collector 26 is opposite to that of the second current collector 27. The plurality of first current collectors 26 are all connected to the positive electrode ear 22 and are all located on the side of the positive electrode ear 22 facing away from the insulating plate 24. The plurality of second current collectors 27 are all connected to the negative electrode ear 23 and are all located on the side of the negative electrode ear 23 facing away from the insulating plate 24. The solutions of the prior art generally lead out the plurality of first current collectors 26 and the plurality of second current collectors 27 directly, and use the plurality of first current collectors 26 as at least a part of the positive electrode ear 22, and use the plurality of second current collectors 27 as the positive electrode ear. As at least a part of the negative electrode ear 23, since the thickness of the multiple first current collectors 26, multiple second current collectors 27 and insulating plate 24 in this solution is relatively thick, if the multiple first current collectors 26 and multiple second current collectors 27 are led outward, it is difficult for the outer film 25 to completely seal the internal battery cell body 21. In this regard, the outer film 25 of this solution is designed to wrap all the first current collectors 26 and all the second current collectors 27 inside. At this time, the thickness of the sealed outer film 25 is only the thickness of the positive electrode ear 22, the negative electrode ear 23 and the insulating plate 24 added together. On the premise that both the positive and negative electrodes of the battery cell body 21 can be led outward, it is easier to ensure the reliability of sealing the internal battery cell body 21. More specifically, when sealing the battery cell body 21, hot melt adhesive can be pre-applied on the inner layer of the outer film 25 and at the positions corresponding to the positive electrode ear 22 and the negative electrode ear 23, or hot melt adhesive can be pre-applied on the front and back sides of the positive electrode ear 22 and the front and back sides of the negative electrode ear 23, and then the outer film 25 completely wraps the entire battery cell body 21, all the first current collectors 26 and all the second current collectors 27, and the outer film 25 wraps part of the insulating plate 24, part of the positive electrode ear 22 and part of the negative electrode ear 23, and then the outer film 25 is hot pressed to melt the innermost layer of the outer film 25 PP and seal each outer edge. At the same time, the applied hot melt adhesive will be filled into the gap between the outer film 25 and the insulating plate 24, the gap between the outer film 25 and the positive electrode ear 22, and the gap between the outer film 25 and the negative electrode ear 23 under the compression of the outer film 25, thereby achieving the purpose of sealing the internal battery cell body 21.

[0051] This embodiment also provides a battery, which includes the battery cell described above. The battery can be in the form of a battery cell, a battery module or a battery pack. Since this battery adopts the above-mentioned battery cell, it also has the advantages of high space utilization, high battery energy density and low internal resistance to adapt to high current usage requirements.

[0052] The above is merely a preferred embodiment of the present invention and only specifically describes the technical principles of the present invention. These descriptions are intended only to explain the principles of the present invention and should not be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention, as well as other specific embodiments of the present invention that can be imagined by those skilled in the art without inventive effort, shall be included within the scope of protection of the present invention.

Claims

1. A battery cell, characterized in that: It includes a battery cell body (21), a positive electrode ear (22), a negative electrode ear (23) and an insulating plate (24); The positive electrode tab (22) and the negative electrode tab (23) are respectively connected to the battery cell body (21) and are arranged on the same side of the battery cell body (21), and the positive electrode tab (22) and the negative electrode tab (23) both extend along the length direction of the battery cell body (21), and the insulating plate (24) is connected between the positive electrode tab (22) and the negative electrode tab (23), and the insulating plate (24) is used to insulate and separate the positive electrode tab (22) and the negative electrode tab (23) in the thickness direction of the battery cell body (21).

2. The battery cell according to claim 1, wherein: The battery core body (21) is a winding structure having a central hole (211) in the middle, the insulating plate (24) is thermally conductive, and the insulating plate (24) extends into the central hole (211) and contacts the wall of the central hole (211).

3. The battery cell according to claim 2, wherein: The battery core body (21) wraps around the outer wall of the insulating plate (24) when being wound.

4. The battery cell according to claim 3, wherein: The outer edges of the insulating plate (24) in contact with the hole wall of the middle hole (211) are all provided with rounded corner structures (241).

5. The battery cell according to claim 1, wherein: After the battery cell body (21) is wound, a first arcuate surface (213) and a second arcuate surface (214) arranged opposite to each other are formed on the outer wall, and the positive electrode tab (22) and the negative electrode tab (23) both extend from the first arcuate surface (213) to the second arcuate surface (214).

6. The battery cell according to claim 3, wherein: The width of the central hole (211) is equal to the width of the insulating plate (24), and the width of the positive electrode tab (22) and the width of the negative electrode tab (23) are both less than or equal to the width of the insulating plate (24).

7. The battery cell according to claim 3, wherein: The insulating plate (24) includes a first end portion (242) and a second end portion (243) that are arranged opposite to each other, wherein the first end portion (242) is used to separate the positive electrode tab (22) and the negative electrode tab (23), and the second end portion (243) extends into the middle hole (211) and does not extend beyond the outer end surface (212) of the battery cell body (21) facing away from the positive electrode tab (22) or the negative electrode tab (23).

8. The battery cell according to claim 1, wherein: The insulating plate (24) is provided with a plurality of holes (244) for accommodating electrolyte.

9. The battery cell according to any one of claims 1 to 8, characterized in that: A plurality of first current collectors (26) and a plurality of second current collectors (27) are led out from the battery cell body (21), the polarity of the first current collectors (26) is opposite to the polarity of the second current collectors (27), the plurality of first current collectors (26) are connected to the positive electrode tab (22) and are all located on the side of the positive electrode tab (22) facing away from the insulating plate (24), and the plurality of second current collectors (27) are connected to the negative electrode tab (23) and are all located on the side of the negative electrode tab (23) facing away from the insulating plate (24); The battery cell further comprises an outer film (25), wherein the outer film (25) wraps the entire battery cell body (21), a plurality of the first current collectors (26) and a plurality of the second current collectors (27), and the outer film (25) wraps part of the insulating plate (24), part of the positive electrode ear (22) and part of the negative electrode ear (23), so that the insulating plate (24), the negative electrode ear (23) and the positive electrode ear (22) are all exposed outward relative to the outer film (25); the gap between the outer film (25) and the insulating plate (24), the gap between the outer film (25) and the positive electrode ear (22), and the gap between the outer film (25) and the negative electrode ear (23) are all filled with hot melt adhesive.

10. A battery, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 9.

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