An electrode assembly, an electric cell, and a battery

Abstract

The application relates to the field of batteries, in particular to an electrode assembly, a battery cell and a battery. The electrode assembly comprises a plurality of separators arranged in a stack, at least two first pole pieces and at least two second pole pieces, adjacent first pole pieces and second pole pieces being separated by a separator; wherein the first pole pieces comprise a first pole piece and a second pole piece; the current collector of the first pole piece is a metal foil, the current collector of the second pole piece is different from the current collector of the first pole piece; and the end of the metal foil is directly connected to the end of the current collector of the second pole piece. In the embodiment of the application, the current collectors of the first pole piece and the second pole piece are different, the current collector of the first pole piece is a metal foil, the end of the metal foil is directly connected to the end of the current collector of the second pole piece; the metal foil and other current collectors do not need to be connected to the pole lug through a process of adapter welding, thereby simplifying the welding process, and the metal foil and other current collectors do not need to be connected to the metal foil through the process of adapter welding.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular, an electrode assembly, a battery cell and a battery. BACKGROUND

[0002] During the preparation of the battery cell, if the positive electrode sheet uses a substrate including an organic support layer and a metal conductive layer arranged on at least one surface of the organic support layer as a current collector, the tab at the end of the positive electrode sheet needs to be welded to the aluminum foil by adapter welding, then die cutting, winding, and then welding to the adapter tab, and finally welding to the positive electrode post. If the negative electrode sheet uses a substrate including an organic support layer and a metal conductive layer arranged on at least one surface of the organic support layer as a current collector, the tab at the end of the negative electrode sheet needs to be welded to the copper foil by adapter welding, then die cutting, winding, and then welding to the adapter tab, and finally welding to the negative electrode post. During the welding process, the tabs are usually welded together by adapter welding, and then welded to the adapter tab. Adapter welding requires the development of new equipment, increases the production process of the battery cell, and causes a decrease in production efficiency and an increase in production cost. SUMMARY

[0003] The purpose of the embodiments of the present application is to provide an electrode assembly, a battery cell and a battery, which aims to simplify the process of connecting the tab to the electrode terminal.

[0004] The present application provides an electrode assembly, which comprises a plurality of separators arranged in a stack, at least two first electrode sheets and at least two second electrode sheets, adjacent first electrode sheets and second electrode sheets are separated by one separator.

[0005] The first electrode sheet includes a first electrode sheet and a second electrode sheet; the current collector of the first electrode sheet is a metal foil, and the current collector of the second electrode sheet includes an organic support layer and a metal conductive layer arranged on at least one surface of the organic support layer; the end of the metal foil is directly connected to the end of the current collector of the second electrode sheet.

[0006] The current collector of the first electrode sheet is a metal foil, and the current collector of the second electrode sheet includes an organic support layer and a metal conductive layer arranged on at least one surface of the organic support layer; the end of the metal foil is directly connected to the end of the current collector of the second electrode sheet, such as direct welding or riveting, etc.; the process of connecting the tab to the adapter tab does not require adapter welding process, and the direct connection method greatly simplifies the welding process.

[0007] In some embodiments of the present application, the first electrode sheet is a positive electrode sheet, and the metal foil is an aluminum foil.

[0008] Alternatively, the first electrode sheet is a negative electrode sheet, and the metal foil is a copper foil.

[0009] In some embodiments of the present application, the second tab includes a third tab and a fourth tab, and the current collector of the fourth tab includes an organic support layer and a metal conductive layer disposed on at least one surface of the organic support layer.

[0010] In some embodiments of the present application, the end of the current collector of the third tab and the end of the current collector of the fourth tab are directly connected.

[0011] In some embodiments of the present application, the electrode assembly includes two first tabs and one second tab, the second tab is located between the two first tabs, and the electrode assembly includes two third tabs and one fourth tab arranged in sequence.

[0012] In some embodiments of the present application, the current collector of the third tab is a metal foil, and the current collector of the third tab is directly connected to the current collector of the fourth tab.

[0013] In some embodiments of the present application, there is at least one first tab between two adjacent second tabs.

[0014] In some embodiments of the present application, one second tab is disposed between two first tabs in the thickness direction of the electrode assembly.

[0015] The present application also provides a battery, which includes a shell and the above-mentioned battery cell, and the battery cell is installed in the shell.

[0016] The present application also provides a battery, which includes a shell and the above-mentioned battery cell, and the battery cell is installed in the shell. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0018] Figure 1 The structural schematic diagram of the electrode assembly provided by the embodiments of the present application is shown.

[0019] Figure 2 The structural schematic diagram of another electrode assembly provided by the embodiments of the present application is shown.

[0020] Figure legend: 100-electrode assembly; 101-separator; 111-first tab; 112-second tab; 121-third tab; 122-fourth tab. DETAILED DESCRIPTION

[0021] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0023] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0024] In the description of the embodiments of the present application, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0025] In addition, the terms "first", "second", "third" and the like are only used to distinguish description, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the embodiments of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set", "mount", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] Embodiments

[0028] Figure 1 The structural schematic diagram of the electrode assembly 100 provided by the embodiments of the present application is shown, please refer toFigure 1 The embodiment provides an electrode assembly 100, which comprises two kinds of pole pieces and a separator 101, the two kinds of pole pieces are opposite in polarity and are respectively a first kind of pole piece and a second kind of pole piece. The first kind of pole piece is a positive pole piece, and the second kind of pole piece is a negative pole piece; or, conversely, the first kind of pole piece is a negative pole piece, and the second kind of pole piece is a positive pole piece. The number of the second kind of pole pieces is two or more than two; the number of the first kind of pole pieces is two or more than two; in other words, the electrode assembly 100 comprises two or more than two positive pole pieces and two or more than two negative pole pieces; two adjacent pole pieces are separated by the separator 101.

[0029] The first kind of pole piece comprises a first pole piece 111 and a second pole piece 112; and the second kind of pole piece comprises a third pole piece 121 and a fourth pole piece 122.

[0030] The first pole piece 111, the third pole piece 121, the second pole piece 112 and the fourth pole piece 122 are arranged in a stack, and two adjacent pole pieces are separated by the separator 101.

[0031] The current collector of the first pole piece 111 is a metal foil, the current collector of the second pole piece 112 comprises an organic support layer and a metal conductive layer arranged on at least one surface of the organic support layer, and the end of the current collector of the first pole piece 111 is directly connected with the end of the current collector of the second pole piece 112. In the present application, the end of the current collector of the first pole piece 111 is directly connected with the end of the current collector of the second pole piece 112 refers to the connection mode except the adapter mode, for example, direct welding and then connecting with an adapter piece, such as laser welding, riveting, such as screwing and the like.

[0032] In the embodiment in which the first pole piece 111 is a positive pole piece, the metal foil is an aluminum foil; and the current collector of the second pole piece 112 can be a positive composite current collector. Further, the positive composite current collector comprises an organic support layer and a metal conductive layer arranged on at least one surface of the organic support layer; wherein the material of the metal conductive layer can be aluminum, aluminum alloy and the like. The material of the organic support layer can be one or more of polyester, polyolefin, polyamide, polyimide, polyether, epoxy resin, phenolic resin, crosslinked products thereof and copolymers thereof, for example.

[0033] In the embodiment in which the first pole piece 111 is a negative pole piece, the metal foil is a copper foil. The current collector of the second pole piece 112 is different from the current collector of the first pole piece 111, and the end of the current collector of the first pole piece 111 is directly connected with the end of the current collector of the second pole piece 112.

[0034] In the embodiment where the first tab 111 is a negative electrode tab, the metal foil is a copper foil; and the current collector of the second tab 112 can be a negative electrode composite current collector. Further, the negative electrode composite current collector comprises an organic support layer and a metal conductive layer disposed on at least one surface of the organic support layer; and the material of the metal conductive layer can be copper, copper alloy, or the like.

[0035] Correspondingly, the material of the organic support layer can be one or more of polyester, polyolefin, polyamide, polyimide, polyether, epoxy resin, phenolic resin, crosslinked products thereof, and copolymers thereof.

[0036] The current collector of the first tab 111 is a metal foil, and the end of the metal foil is directly connected to the end of the current collector of the second tab 112; the metal foil and the composite current collector can be directly connected, and then connected to the adapter tab, thereby simplifying the welding process and reducing the manufacturing cost.

[0037] In the embodiments of the present application, the current collectors of the plurality of second tabs can be the same or different; as described above, the second tabs include the third tab 121 and the fourth tab 122, and the current collectors of the third tab 121 and the fourth tab 122 can be the same.

[0038] Alternatively, the current collectors of the third tab 121 and the fourth tab 122 can be different.

[0039] For example, in the embodiment where the first tab 111 is a negative electrode tab, the current collector of the third tab 121 and the current collector of the fourth tab 122 can both be aluminum foils, or the current collector of the third tab 121 and the current collector of the fourth tab 122 can both be positive electrode composite current collectors; or one of the current collector of the third tab 121 and the current collector of the fourth tab 122 is an aluminum foil, and the other is a positive electrode composite current collector; wherein the positive electrode composite current collector comprises an organic support layer and a metal layer disposed on at least one surface of the organic support layer, the metal layer can be one layer or multiple layers, and the material of the metal layer can be aluminum or aluminum alloy, or the like.

[0040] Correspondingly, in the embodiment where the first tab 111 is a positive electrode tab, the current collector of the third tab 121 and the current collector of the fourth tab 122 can both be copper foils, or the current collector of the third tab 121 and the current collector of the fourth tab 122 can both be negative electrode composite current collectors; or one of the current collector of the third tab 121 and the current collector of the fourth tab 122 is a copper foil, and the other is a negative electrode composite current collector.

[0041] In the embodiment of the present application, the current collector end of the third tab 121 and the current collector end of the fourth tab 122 are directly connected; no longer need to be welded through the adapter tab, and no longer need to be welded with the adapter tab in the connection process; the tab is directly connected and then connected with the adapter tab, and the tab of the third tab 121 and the tab of the fourth tab 122 are directly connected with the adapter tab after being connected, which can simplify the connection process, and at the same time, will not affect the current flow of the tab to the electrode terminal.

[0042] Please refer again to Figure 1 , in Figure 1 , the electrode assembly 100 includes four tabs, two positive tabs and two negative tabs; the electrode assembly 100 includes two separators 101.

[0043] In Figure 1 , along the thickness direction of the electrode assembly 100, the first tab 111, the separator 101, the third tab 121, the separator 101, the second tab 112, the separator 101, and the fourth tab 122 are sequentially arranged.

[0044] The current collector of the first tab 111 is a copper foil, the current collector of the second tab 112 is a negative composite current collector, the current collector of the third tab 121 is a positive composite current collector, and the current collector of the fourth tab 122 is an aluminum foil; with this arrangement, the two can be welded.

[0045] For other embodiments in which the current collector of the first tab 111 is an aluminum foil, the current collector of the second tab 112 is a positive composite current collector, the current collector of the third tab 121 is a negative composite current collector, and the current collector of the fourth tab 122 is a copper foil, the welding process is also simplified accordingly.

[0046] It should be noted that in other embodiments of the present application, the first tab 111, the second tab 112, the third tab 121, and the fourth tab 122 can be combined in other combinations.

[0047] Figure 2 Another structure of the electrode assembly 100 provided by the embodiment of the present application is shown in the structure diagram, please refer to Figure 1 and Figure 2 , in Figure 2 , the electrode assembly 100 includes three first tabs and three second tabs.

[0048] In Figure 2In the shown embodiment, the first pole piece includes three pole pieces, two first pole pieces 111 and one second pole piece 112; the second pole piece 112 is located between the two first pole pieces 111, the current collector of the first pole piece 111 is a metal foil, and the current collector of the second pole piece 112 is a composite current collector. After the electrode assembly 100 is wound or laminated, the second pole piece 112 is directly connected with the tabs of the first pole piece 111, and after the tabs of the two are connected, the current of the second pole piece 112 can be conducted out through the metal foils of the first pole pieces 111 on both sides, thereby having a better current conducting effect.

[0049] In the embodiment in which the electrode assembly 100 includes a plurality of pole pieces, the pole pieces of the same polarity are arranged in a manner that the metal foils are on both sides and the composite current collector is in the middle, which can increase the current conducting effect. In other words, for the pole pieces of the same polarity, the composite current collector has metal foils on both sides. It should be noted that "the composite current collector has metal foils on both sides" means that for the pole pieces of the same polarity, there are also pole pieces of opposite polarity and separators between the pole pieces of the same polarity.

[0050] By way of example, the electrode assembly 100 includes three first pole pieces and three second pole pieces as an example, the arrangement of the three first pole pieces can be: the first pole piece 111, the second pole piece 112, and the first pole piece 111 arranged in sequence; and the arrangement of the three second pole pieces is the third pole piece 121, the third pole piece 121, and the fourth pole piece 122. In other words, the arrangement of the pole pieces of the electrode assembly 100 is: the first pole piece 111, the third pole piece 121, the second pole piece 112, the third pole piece 121, the first pole piece 111, and the fourth pole piece 122. This arrangement can make the composite current collector have metal current collectors on both sides, thereby increasing the current conducting effect. In addition, after the electrode assembly 100 is wound, the tabs on both sides of the fourth pole piece 122 can be connected with the metal foils, thereby increasing the current conducting effect.

[0051] It should be noted that in the embodiments of the present application, the current collectors of the pole pieces located at both ends of the electrode assembly 100 in the thickness direction of the electrode assembly 100 are metal foils; the arrangement of the three pole pieces of the same polarity with the metal foil current collector located between the two composite current collectors does not conflict; and it can be implemented in the same embodiment, for example, in the embodiment in which the electrode assembly 100 includes more pole pieces.

[0052] It should be noted that in some embodiments of the present application, the current collector of the pole piece located at the end of the electrode assembly 100 can not be a metal foil, for example, it can be a composite current collector.

[0053] In addition, for the same polarity of the number of pole pieces greater than or equal to three, the arrangement of the three pole pieces of the same polarity is not limited to the arrangement of the metal foil current collector between the two composite current collectors, for example, it can be two composite current collectors, one metal foil current collector arranged in sequence.

[0054] Alternatively, in some embodiments, for the same polarity of the pole piece, the number of pole pieces with the composite current collector and the number of pole pieces with the metal foil current collector can be arbitrarily distributed, not limited to two pole pieces with the composite current collector and one pole piece with the metal foil current collector. On this basis, the arrangement of the plurality of pole pieces of the same polarity can be arbitrarily combined.

[0055] Please refer again to Figure 2 In the embodiment, the first pole piece includes two first pole pieces 111 and one second pole piece 112, and the second pole piece 112 is arranged between the two first pole pieces 111. Correspondingly, the second pole piece includes two third pole pieces 121 and one fourth pole piece 122, and the fourth pole piece 122 is arranged between the two third pole pieces 121. It can be understood that in other embodiments of the present application, one third pole piece 121 and two fourth pole pieces 122 can be arranged in sequence. Correspondingly, the first pole piece 111 can be located at the end of the electrode assembly 100, and the second pole piece 112 can also be located at the end of the electrode assembly 100; or the third pole piece 121 can be located at the end of the electrode assembly 100, or the fourth pole piece 122 can also be located at the end of the electrode assembly 100.

[0056] Further, the number of pole pieces of the same polarity in the electrode assembly 100 is not limited to Figure 1 two, nor Figure 2 three, for example, it can be four, five or more. The current collector of at least one of the pole pieces of the same polarity is a metal foil, and the current collectors of the pole pieces of the same polarity are connected in a direct connection manner.

[0057] Further, in the embodiments of the present application, the welded ends of the current collectors of the two opposite polarities in the electrode assembly 100 can be located on the same side of the electrode assembly 100, that is, the welding positions of the two tabs are located on the same side of the electrode assembly 100; or the welded ends of the current collectors of the two opposite polarities can be located on both sides of the electrode assembly 100, that is, the welding positions of the two tabs are located on both sides of the electrode assembly 100.

[0058] The electrode assembly 100 provided by the embodiments of the present application has at least the following advantages:

[0059] The current collector of the pole piece of the same polarity in the electrode assembly is at least one metal foil, at least one current collector is a composite current collector, the pole lug of the current collector of the pole piece of the same polarity is directly connected without using relay welding, and the welding process can be simplified.

[0060] The application also provides an electric core, which comprises the electrode assembly 100 and an electrolyte.

[0061] The application also provides a battery, which comprises the electric core and a shell.

[0062] The electric core and the battery provided by the application have the advantages of the electrode assembly 100, the welding process can be simplified, and the cost is reduced because the current collector is directly connected without using relay welding.

[0063] The above only describes the preferred embodiments of the application and is not used to limit the application. Various modifications and changes can be made by those skilled in the art based on the principles and spirit of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. An electrode assembly, characterized in that, The electrode assembly includes multiple diaphragms stacked together, at least two first type electrodes and at least two second type electrodes, with adjacent first type electrodes and second type electrodes separated by one of the diaphragms; The first type of electrode includes two first electrode sheets and one second electrode sheet, with the second electrode sheet located between the two first electrode sheets along the thickness direction of the electrode assembly. The current collector of the first electrode is a metal foil, and the current collector of the second electrode includes an organic support layer and a metal conductive layer disposed on at least one surface of the organic support layer; the tabs at the ends of the metal foil are directly connected to the tabs at the ends of the current collector of the second electrode. The organic support layer is made of one or more of the following materials: polyester, polyolefin, polyamide, polyimide, polyether, epoxy resin, phenolic resin, their crosslinks, and their copolymers.

2. The electrode assembly according to claim 1, characterized in that, The first electrode is a positive electrode, and the metal foil is an aluminum foil; Alternatively, the first electrode may be a negative electrode, and the metal foil may be a copper foil.

3. The electrode assembly according to claim 1, characterized in that, The second type of electrode includes a third electrode and a fourth electrode. The current collector of the fourth electrode includes an organic support layer and a metal conductive layer disposed on at least one surface of the organic support layer.

4. The electrode assembly according to claim 3, characterized in that, The end of the current collector of the third electrode and the end of the current collector of the fourth electrode are directly connected.

5. The electrode assembly according to claim 3, characterized in that, The current collector of the third electrode is a metal foil, and the current collector of the third electrode is directly connected to the current collector of the fourth electrode.

6. The electrode assembly according to claim 3, characterized in that, The electrode assembly includes two third electrodes and one fourth electrode arranged in sequence.

7. The electrode assembly according to any one of claims 1-5, characterized in that, There is at least one first electrode between two adjacent second electrodes.

8. A battery cell, characterized in that, The battery cell includes an electrolyte and an electrode assembly according to any one of claims 1-7, which is immersed in the electrolyte.

9. A battery, characterized in that, The battery includes a housing and a cell as described in claim 8, wherein the cell is installed within the housing.

Images