Cells and Batteries

Abstract

The utility model discloses a battery cell and a battery. The battery cell includes a first pole piece and a second pole piece, the first pole piece includes a first current collector, an active material layer and a plurality of first pole ears, the first current collector includes an intermediate layer and a metal layer, the two sides of the intermediate layer in the thickness direction are respectively connected with metal layers, the active material layer is connected to at least one side of the first current collector in the thickness direction, the two ends of the first current collector in the length direction are respectively protruding from the active material layer along the length of the first current collector, the two ends of the first current collector in the length direction are respectively provided with at least one first pole ear, and the first pole ear is connected to the metal layer. The second pole piece includes a second current collector and a second pole ear, the second current collector has a middle region between the two ends in the length direction, and the second pole ear is connected to the middle region. The battery cell of the present application combines the advantages of the pole ear center structure and the composite current collector, effectively improving the electrical performance and safety performance of the battery cell.

Description

Technical Field

[0001] The utility model relates to the technical field of battery preparation, in particular to an electric core and a battery. Background Art

[0002] The related technology designs a structure with a central lug, which is achieved by laser cleaning and processing the slots in the middle area of ​​the active material layer of the pole piece, and welding the lugs to the positions corresponding to the slots, so as to obtain a battery cell with a central lug after the pole piece is wound. Because the lug is located in the middle of the pole piece, the transmission distance of electrons on the pole piece is reduced, the battery cell is fully charged in a shorter time, the charging temperature rise is reduced, and the internal resistance of the battery cell is reduced, which effectively improves the electrical performance. Compared with traditional current collectors, composite current collectors can improve the safety performance of battery cells, but the middle layer of the composite current collector is a polymer layer. During laser cleaning, heat shrinkage will occur at the slots, which will affect the welding of the lugs, making it difficult to apply the central lug structure. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a battery core that can improve the electrical performance and safety performance of the battery core.

[0004] The utility model also provides a battery having the battery core.

[0005] According to the battery cell of the embodiment of the utility model, it includes a first pole piece and a second pole piece, the first pole piece includes a first current collector, an active material layer and a plurality of first pole tabs, the first current collector includes an intermediate layer and a metal layer, the metal layer is connected to both sides of the intermediate layer in the thickness direction, the active material layer is connected to at least one side of the first current collector in the thickness direction, the first current collector protrudes from the active material layer along the length direction of the first current collector at both ends in the length direction, the first current collector is provided with at least one first pole tab at both ends in the length direction, and the first pole tab is connected to the metal layer. The second pole piece includes a second current collector and a second pole tab, the second current collector has a middle region between the two ends in the length direction, and the second pole tab is connected to the middle region.

[0006] The battery cell according to the embodiment of the utility model has at least the following beneficial effects: the first current collector of the first pole piece is set as a composite current collector, which can effectively reduce the overall weight of the battery cell and improve the safety performance of the battery cell, improve the overall energy density of the battery cell, and by connecting at least one first pole ear at both ends of the length direction of the first current collector, the current can flow from both ends of the head and tail of the first pole piece at the same time, shortening the electron transfer time and further improving the electrical performance of the battery cell. The second pole piece adopts a conventional current collector and a pole ear center structure to improve the electrical performance of the battery cell. The battery cell of the present application combines the advantages of the pole ear center structure and the composite current collector, effectively improving the electrical performance and safety performance of the battery cell.

[0007] According to some embodiments of the utility model, the first pole piece further includes a connector, which connects the first pole ear and the metal layer, the thickness of the connector is a, the thickness of the metal layer is b, and the thickness of the first pole ear is c, satisfying: a>b, a<c.

[0008] According to some embodiments of the present invention, the connecting member includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the metal layer, the second connecting portion protrudes from the first current collector in the width direction of the first current collector, and the second connecting portion is connected to the first pole ear.

[0009] According to some embodiments of the present invention, the first electrode tab is connected to a side of the second connecting portion that is relatively close to the first current collector in the thickness direction of the first current collector.

[0010] According to some embodiments of the present invention, the thickness of the second pole tab is D1, satisfying: a≤D1.

[0011] According to some embodiments of the present invention, the first pole ear is connected to a side of the connector relatively away from the first current collector in the thickness direction of the first current collector, the sum of the thickness of the first pole ear and the thickness of the connector is D2, and the thickness of the second pole ear is D1, satisfying: D2≤D1.

[0012] According to some embodiments of the present invention, the metal layers on both sides of the intermediate layer are respectively connected to at least one of the first pole tabs.

[0013] According to some embodiments of the present invention, the first pole sheet and the second pole sheet are wound to form the battery core, and the first pole tab and the second pole tab are staggered in the thickness direction of the first current collector, and / or the first pole tabs are staggered in the thickness direction of the first current collector.

[0014] According to some embodiments of the present invention, the area between the two ends of the second current collector along the length direction has a length L, and the area between 35%L and 65%L starting from one end along the length direction on the second current collector is the middle area.

[0015] A battery according to an embodiment of the utility model includes a battery cell in any of the above embodiments.

[0016] The battery according to the embodiment of the utility model has at least the following beneficial effects: by applying the battery cell of the embodiment of the application, the electrical performance and safety performance of the battery can be improved.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0019] Figure 1 A schematic diagram of a first pole piece of a battery cell according to an embodiment of the utility model;

[0020] Figure 2 for Figure 1 A top view of

[0021] Figure 3 It is a partial schematic diagram of a first pole piece of a battery cell according to another embodiment of the utility model;

[0022] Figure 4 for Figure 1 Schematic diagram of the first current collector in;

[0023] Figure 5 A schematic diagram of a second pole piece of a battery cell according to an embodiment of the utility model;

[0024] Figure 6 for Figure 5 Side view of

[0025] Figure 7 Schematic diagram of a battery cell according to an embodiment of the utility model.

[0026] Reference numerals:

[0027] Battery cell 10;

[0028] A first pole piece 100, a first current collector 110, an intermediate layer 111, a metal layer 112, a first pole tab 120, an active material layer 130, a connector 140, a first connecting portion 141, and a second connecting portion 142;

[0029] A second pole piece 200 , a second current collector 210 , a second pole tab 220 , and a middle region 230 . DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below, and 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 only used to explain the present invention, and cannot be understood as limiting the present invention.

[0031] In the description of the present invention, it should be understood that descriptions involving orientation, 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, and 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, and therefore cannot be understood as a limitation on the present invention.

[0032] In the description of the present utility model, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0033] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. 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.

[0034] In the description of the utility model, the description with reference to the terms "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 utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0035] In response to the problem that it is difficult to apply the center-pole ear structure to the composite current collector in the related technology, making it difficult to combine the advantages, the present application sets the two pole pieces of the battery cell as a composite current collector and a common current collector respectively. The common current collector applies the center-pole ear structure to improve the electrical performance. The composite current collector is provided with pole ears at both ends in the length direction to ensure the electrical performance on the basis of improving the safety performance. The advantages of the composite current collector and the center-pole ear structure are combined to improve the overall electrical performance and safety performance of the battery cell.

[0036] The following describes the battery cells and batteries of the embodiments of the present application with reference to the drawings in the specification. It should be noted that in the drawings, the thickness direction is shown in the up-down direction, the length direction is shown in the left-right direction, and the width direction is shown in the front-back direction.

[0037] Reference Figures 1 to 7According to the battery cell 10 of the embodiment of the utility model, it includes a first pole piece 100 and a second pole piece 200. The first pole piece 100 includes a first current collector 110, an active material layer 130 and a plurality of first pole tabs 120. The first current collector 110 includes an intermediate layer 111 and a metal layer 112. The metal layer 112 is connected to both sides of the intermediate layer 111 in the thickness direction. The active material layer 130 is connected to at least one side of the first current collector 110 in the thickness direction. The two ends of the first current collector 110 in the length direction protrude from the active material layer 130 along the length direction of the first current collector 110, respectively, to provide a connection space for the first pole tab 120, and there is no need to remove the active material layer 130. At least one first pole tab 120 is provided at both ends of the first current collector 110 in the length direction, and the first pole tab 120 is connected to the metal layer 112. The first current collector 110 of the first pole piece 100 is configured as a composite current collector, which can effectively reduce the overall weight of the battery cell 10 and improve the safety performance of the battery cell 10, thereby increasing the overall energy density of the battery cell 10. In addition, by connecting at least one first pole ear 120 at both ends of the length direction of the first current collector 110, current can flow from both ends of the first pole piece 100 at the same time, thereby shortening the electron transfer time and further improving the electrical performance of the battery cell 10.

[0038] The second pole piece 200 includes a second current collector 210 and a second pole tab 220. The second current collector 210 has a middle region 230 between the two ends along the length direction, and the second pole tab 220 is connected to the middle region 230. The second pole piece 200 adopts a conventional current collector and a pole tab middle structure to improve the electrical performance of the battery cell 10. The battery cell 10 of the present application combines the advantages of the pole tab middle structure and the composite current collector, effectively improving the electrical performance and safety performance of the battery cell 10.

[0039] Specifically, the metal layers 112 on both sides can be the same metal or different metals. The polymer layer of the middle layer 111 plays a supporting role, and the metal layers 112 on both sides play a conductive role. The thickness of the conductive metal layers 112 on both sides is less than that of the conventional current collector. When the battery cell 10 is subjected to a mechanical abuse safety test, the contact area between the composite current collector and the other electrode is small, which can reduce short-circuit contact points and improve safety performance. The first pole piece 100 can be directly connected to the metal layer 112.

[0040] Reference Figure 3In some embodiments, the first pole piece 100 further includes a connector 140, which connects the first pole tab 120 and the metal layer 112. The thickness of the connector 140 is a, the thickness of the metal layer 112 is b, and the thickness of the first pole tab 120 is c, satisfying: a>b, a<c. The metal layer 112 of the first current collector 110 is relatively thin, and the pole tab is usually set thicker to ensure the flow capacity. It is difficult to directly weld the metal layer 112 with the thicker pole tab and the defect rate is high. By introducing a connector 140 with a thickness greater than the metal layer 112 and a thickness less than the first pole tab 120, the thickness difference between the two welded components during welding can be minimized while ensuring that the connector 140 has a certain thickness to facilitate welding, so as to reduce the difficulty of welding. Moreover, since the connector 140 itself has a certain thickness and has conductivity, the first pole tab 120 can be selected as a pole tab with a smaller thickness. Specifically, the connecting member 140 can be made of the same metal foil as a conventional current collector, or can be made of the same metal as the first electrode tab 120 .

[0041] Reference Figure 3 Furthermore, the connector 140 includes a first connector 141 and a second connector 142, wherein the first connector 141 is connected to the metal layer 112, the second connector 142 protrudes from the first current collector 110 in the width direction of the first current collector 110, and the second connector 142 is connected to the first pole tab 120. By connecting the first pole tab 120 to the second connector 142 protruding from the first current collector 110, the thickness of the first current collector 110 and the second current collector 210 corresponding to the first pole sheet 100 and the second pole sheet 200 can be reduced, thereby reducing the overall thickness of the battery cell 10 and improving the overall energy density of the battery cell 10.

[0042] Reference Figure 3 and Figure 6 In the embodiment where the first pole tab 120 is connected to the second connection portion 142, the thickness of the second pole tab 220 is D1, satisfying: a≤D1. After the first pole piece 100 and the second pole piece 200 are wound, the thickness of the first connection portion 141 and the thickness of the second pole tab 220 will affect the overall thickness and flatness of the battery cell 10. Controlling a≤D1 can reduce the influence of the connector 140 on the maximum thickness and flatness of the battery cell 10 on the basis of ensuring that the connector 140 is easy to weld with the metal layer 112, reduce the probability of uneven protrusions on the outer surface of the battery cell 10, and ensure the overall energy density of the battery cell 10.

[0043] Reference Figure 3In the embodiment where the first pole ear 120 is connected to the second connecting portion 142, the first pole ear 120 is connected to the second connecting portion 142 on a side of the first current collector 110 that is relatively close to the first current collector 110 in the thickness direction of the first current collector 110, so that the first pole ear 120 and the first current collector 110 overlap in thickness space, thereby improving space utilization, reducing structural interference, and making the battery cell 10 structure more compact.

[0044] Reference Figure 3 and Figure 6 In some embodiments, the first pole tab 120 is connected to the side of the connector 140 relatively far away from the first current collector 110 in the thickness direction of the first current collector 110, that is, the first pole tab 120 is directly connected to the side of the first connecting portion 141 away from the first current collector 110. On this basis, the sum of the thickness of the first pole tab 120 and the thickness of the connector 140 is D2, and the thickness of the second pole tab 220 is D1, satisfying: D2≤D1. After the first pole sheet 100 and the second pole sheet 200 are wound, the sum of the thickness of the connector 140 and the first pole tab 120 and the thickness of the second pole tab 220 will affect the overall thickness and flatness of the battery cell 10. Controlling D2≤D1 can reduce the influence of the connector 140 and the first pole tab 120 on the maximum thickness and flatness of the battery cell 10, reduce the probability of uneven protrusions on the outer surface of the battery cell 10, and ensure the overall energy density of the battery cell 10.

[0045] In some embodiments, the first tabs 120 located at both ends of the first current collector 110 in the length direction are respectively connected to the same metal layer 112, and the two metal layers 112 of the first current collector 110 are subsequently electrically connected to achieve conduction. Figure 1 and Figure 2 The metal layers 112 on both sides of the middle layer 111 are respectively connected with at least one first pole tab 120. The first pole tabs 120 connecting the two metal layers 112 can be electrically connected to achieve the conduction of the two metal layers 112, which is convenient for the subsequent process. The first pole tabs 120 connecting the two metal layers 112 can be located on the same side of the length direction of the first current collector 110, or can be located on both sides of the length direction of the first current collector 110.

[0046] Reference Figure 7 In some embodiments, the first pole sheet 100 and the second pole sheet 200 are wound to form the battery cell 10, and the first pole ear 120 and the second pole ear 220 are staggered in the thickness direction of the first current collector 110, that is, after the first pole sheet 100 and the second pole sheet 200 are stacked, the first pole ear 120 and the second pole ear 220 do not overlap at all in the thickness direction, so as to reasonably utilize the overall space, improve the flatness of the battery cell 10, reduce the maximum thickness of the battery cell 10, and improve the overall energy density of the battery cell 10.

[0047] Reference Figure 7 In some embodiments, the first pole sheet 100 and the second pole sheet 200 are wound to form the battery cell 10, and the first pole ears 120 are staggered in the thickness direction of the first current collector 110, that is, after the first pole sheet 100 and the second pole sheet 200 are stacked, the first pole ears 120 do not overlap at all in the thickness direction, so as to reasonably utilize the overall space, improve the flatness of the battery cell 10, reduce the maximum thickness of the battery cell 10, and improve the overall energy density of the battery cell 10.

[0048] Reference Figure 5 In some embodiments, the second current collector 210 has a length L, and the length region of 35%L to 65%L is the middle region 230. The second pole ear 220 is set in the range of 35%L to 65%L of the second current collector 210, which can ensure the realization of the pole ear center structure, reduce the transmission distance of electrons on the pole piece, reduce the full charging time of the battery cell 10, reduce the charging temperature rise, and reduce the internal resistance of the battery cell 10, effectively improving the electrical performance.

[0049] Reference Figure 7 The battery according to the embodiment of the utility model includes the battery cell 10 of any of the above embodiments. By applying the battery cell 10 of the embodiment of the present application, the electrical performance and safety performance of the battery can be improved.

[0050] It should be noted that in Figure 7 In the figure, the length direction of the first pole piece 100 and the second pole piece 200 is the winding direction, and the thickness direction of the first pole piece 100 and the second pole piece 200 is the normal direction of the tangent line taken at any point on the first pole piece 100 or the second pole piece 200.

[0051] The embodiments of the utility model are described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the utility model. In addition, the embodiments of the utility model and the features in the embodiments can be combined with each other without conflict.

Claims

1. A battery cell, characterized in that: include: A first pole sheet, comprising a first current collector, an active material layer and a first pole tab, wherein the first current collector comprises an intermediate layer and a metal layer, the metal layers are connected to both sides of the intermediate layer in a thickness direction, the active material layer is connected to at least one side of the first current collector in a thickness direction, both ends of the first current collector in a length direction protrude from the active material layer along the length direction of the first current collector, and at least one first pole tab is provided at both ends of the first current collector in a length direction, and the first pole tab is connected to the metal layer; The second pole piece includes a second current collector and a second pole tab. The second current collector has a middle region between two ends along the length direction, and the second pole tab is connected to the middle region.

2. The battery cell according to claim 1, characterized in that: The first pole piece further includes a connector, which connects the first pole lug and the metal layer. The thickness of the connector is a, the thickness of the metal layer is b, and the thickness of the first pole lug is c, satisfying: a>b, a<c.

3. The battery cell according to claim 2, characterized in that: The connecting member includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the metal layer, the second connecting portion protrudes from the first current collector in a width direction of the first current collector, and the second connecting portion is connected to the first electrode tab.

4. The battery cell according to claim 3, characterized in that: The first electrode tab is connected to a side of the second connection portion that is relatively close to the first current collector in a thickness direction of the first current collector.

5. The battery cell according to claim 3, characterized in that: The thickness of the second electrode tab is D1, satisfying: a≤D1.

6. The battery cell according to claim 2, characterized in that: The first pole tab is connected to a side of the connector relatively far away from the first current collector in the thickness direction of the first current collector, the sum of the thickness of the first pole tab and the thickness of the connector is D2, the thickness of the second pole tab is D1, and D2≤D1 is satisfied.

7. The battery cell according to claim 1, characterized in that: The metal layers on both sides of the middle layer are respectively connected with at least one of the first electrode tabs.

8. The battery cell according to claim 1, characterized in that: The first pole sheet and the second pole sheet are wound to form the battery core, and the first pole tab and the second pole tab are staggered in the thickness direction of the first current collector, and / or the first pole tabs are staggered in the thickness direction of the first current collector.

9. The battery cell according to claim 1, characterized in that: The region between the two ends of the second current collector along the length direction has a length L, and the region between 35%L and 65%L starting from one end along the length direction of the second current collector is the middle region.

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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