Battery cell, lithium ion battery manufacturing method, and lithium ion battery

Abstract

The present application discloses a battery cell, a lithium ion battery manufacturing method, and a lithium ion battery. The battery cell comprises a body and tab assemblies; each tab assembly comprises a dummy tab group, an outer tab, and a tab adhesive; the dummy tab group comprises at least one dummy tab connected to the body; the outer tab is conductively connected to the dummy tab group; in a projection in the thickness direction of the body, the outer tab and the dummy tab group partially overlap to form an overlapping portion, and the tab adhesive is wrapped around at least part of the overlapping portion; two tab assemblies are provided, and the two tab assemblies are staggered in the width direction of the body. The distance between the tab adhesives and the body is closer, the dummy tabs do not need to be folded, and a top sealing process step is directly performed at the positions of the tab adhesives after the battery cell is placed into a packaging housing, so that the space occupied by the tab assemblies between the body and the top sealing positions can be reduced, improving the energy density of the lithium ion battery, and the production steps of the lithium ion battery can be simplified, improving the production efficiency of the lithium ion battery.

Description

Battery cell, lithium ion battery manufacturing method and lithium ion battery Technical Field

[0001] The present application relates to the technical field of lithium-ion batteries, and in particular to a battery cell, a method for manufacturing a lithium-ion battery, and a lithium-ion battery. Background Art

[0002] Lithium-ion batteries are widely used in 3C digital products such as mobile phones, mobile power supplies, smart wearables, as well as in fields such as solar street light energy storage and new energy vehicle power batteries due to their advantages such as high specific energy, low self-discharge, light weight and environmental friendliness. Battery cells have been widely used due to their high charge rate. Multiple false tabs are connected to the main body of the battery cell. During the manufacturing process, the false tabs need to be pre-welded first, and then the outer tabs are welded to the false tabs. Finally, the battery cell is placed in the packaging shell so that the main body and the false tabs are located inside the packaging shell, and the outer tabs partially extend outside the packaging shell. In the lithium-ion battery formed by the above method, the false tabs occupy a large space and have a low energy density. In order to reduce the space occupied by the false tabs, the false tabs can be folded before the battery cell is placed in the shell, but this will increase the production steps of the lithium-ion battery, resulting in lower production efficiency. In addition, the folded false tabs still occupy a certain amount of space in the lithium-ion battery, resulting in a low energy density.

[0003] Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a battery cell that can reduce the space occupied by the tab assembly between the body and the top seal, thereby increasing the energy density of the lithium-ion battery, and can also simplify the production steps of the lithium-ion battery and improve the production efficiency of the lithium-ion battery.

[0005] The present application also proposes a lithium-ion battery manufacturing method for manufacturing a lithium-ion battery including the above-mentioned battery cell.

[0006] The present application also proposes a lithium-ion battery comprising the above-mentioned battery cell.

[0007] A battery cell provided in an embodiment of the first aspect of the present application includes:

[0008] ontology;

[0009] A tab assembly includes a fake tab group, an outer tab and tab glue. The fake tab group includes at least one fake tab connected to the body. The outer tab is conductively connected to the fake tab group. In the projection along the thickness direction of the body, the outer tab and the fake tab group partially overlap to form an overlapping portion. The tab glue is wrapped around at least part of the overlapping portion. Two tab assemblies are provided, and the two tab assemblies are staggered in the width direction of the body.

[0010] The battery cell provided by the first embodiment of the present application has at least the following beneficial effects:

[0011] In a battery cell provided in the first embodiment of the present application, the tab glue is wrapped around the overlapping portion formed by the outer tab and the dummy tab group. Compared with the related art in which the tab glue is arranged on the outer tab, the distance between the tab glue and the body of the battery cell provided in the first embodiment of the present application is closer. When the battery cell provided in the first embodiment of the present application is applied to a lithium-ion battery, there is no need to fold the dummy tab. After the battery cell is placed in the packaging shell, the top sealing process can be performed directly at the position where the tab glue is located. This can not only reduce the space occupied by the tab assembly between the body and the top sealing position, thereby improving the energy density of the lithium-ion battery, but also simplify the production steps of the lithium-ion battery, thereby improving the production efficiency of the lithium-ion battery.

[0012] In some embodiments of the present application, the tab glue includes a first film and a second film, the first film and the second film are respectively arranged on both sides of the overlapping portion in the thickness direction, and the first film and the second film are bonded to each other on both sides of the overlapping portion in the width direction.

[0013] In some embodiments of the present application, one end of the first film in the length direction of the overlapping portion is bonded to one side of the external tab in the thickness direction of the overlapping portion, and one end of the second film in the length direction of the overlapping portion is bonded to the other side of the external tab in the thickness direction of the overlapping portion.

[0014] In some embodiments of the present application, the tab glue is an integrated structure.

[0015] In some embodiments of the present application, the tab glue is wrapped around an end of the dummy tab group away from the body.

[0016] In some embodiments of the present application, the dummy tab group includes a plurality of dummy tabs, and the plurality of dummy tabs are arranged in sequence along the thickness direction of the body.

[0017] In some embodiments of the present application, the body includes a first pole piece and a second pole piece, the first pole piece and the second pole piece are stacked and wound, the fake pole piece in one of the fake pole piece groups is connected to the first pole piece, and the fake pole piece in the other fake pole piece group is connected to the second pole piece.

[0018] In some embodiments of the present application, the main body includes multiple first pole pieces and multiple second pole pieces, and the multiple first pole pieces and the multiple second pole pieces are alternately stacked, wherein the multiple fake pole pieces in one of the fake pole piece groups are connected to the multiple first pole pieces one by one, and the multiple fake pole pieces in another fake pole piece group are connected to the multiple second pole pieces one by one.

[0019] In some embodiments of the present application, the dimension of the tab glue along the length direction of the body is 0.5 mm to 10 mm;

[0020] and / or,

[0021] The dimension of the tab glue along the width direction of the body is 1 mm to 25 mm;

[0022] and / or,

[0023] The dimension of the tab glue along the thickness direction of the body is 0.002 mm to 0.5 mm.

[0024] A second aspect of the present application provides a method for manufacturing a lithium-ion battery, which is used to manufacture a lithium-ion battery including the multi-electrode battery provided by any embodiment of the first aspect of the present application. The method comprises the following steps:

[0025] Taking or preparing a combination of the main body and the dummy tab group;

[0026] The outer tab and the dummy tab group are partially overlapped in the thickness direction of the body to form the overlapping portion;

[0027] Welding the outer tab to the plurality of dummy tabs in the dummy tab group;

[0028] Making the tab glue on the overlapping portion to form a battery core;

[0029] Take or prepare a packaging shell, place the battery cell into the packaging shell, and clamp the tab glue between the two shells of the packaging shell.

[0030] A lithium-ion battery manufacturing method provided in an embodiment of the second aspect of the present application has at least the following beneficial effects:

[0031] In the lithium-ion battery manufacturing method provided by the second embodiment of the present application, the battery cell provided by the first embodiment of the present application is first prepared, and the tab glue is wrapped on the overlapping portion formed by the overlap of the outer tab and the dummy tab group. Compared with the related art in which the tab glue is set on the outer tab, the distance between the tab glue and the body of the battery cell provided by the first embodiment of the present application is closer. After the battery cell is prepared, there is no need to fold the dummy tab. After the battery cell is placed in the packaging shell, the top sealing process is directly performed at the position where the tab glue is located to complete the manufacture of the lithium-ion battery. On the one hand, the space occupied by the tab assembly between the body and the top sealing position is small, which can improve the energy density of the lithium-ion battery. On the other hand, the production steps of the lithium-ion battery are relatively simple, which can improve the production efficiency of the lithium-ion battery.

[0032] In some embodiments of the present application, the step of making the tab glue on the overlapping portion includes the following steps:

[0033] After the outer tabs are welded to the plurality of dummy tabs in the dummy tab group, the overlapping portion is placed in an injection mold, and plastic material is injected into the injection mold and solidified to form the tab glue wrapped around the overlapping portion.

[0034] In some embodiments of the present application, the step of making the tab glue on the overlapping portion includes the following steps:

[0035] obtaining or preparing a first film and a second film;

[0036] After the outer tab is welded to the plurality of dummy tabs in the dummy tab group, the first film is pasted on one side of the overlapping portion in the thickness direction, and the second film is pasted on the other side of the overlapping portion in the thickness direction, and the first film and the second film are pasted to each other on both sides of the overlapping portion in the width direction.

[0037] In some embodiments of the present application, the step of making the tab glue on the overlapping portion includes the following steps:

[0038] obtaining or preparing a first film and a second film;

[0039] The outer tab includes an exposed area, a pre-bonding area, and a welding area sequentially connected along its length direction; one end of the first film is bonded to one side of the pre-bonding area in the thickness direction, so that the remaining portion of the first film is located on a side of the pre-bonding area close to the welding area and separated from the welding area; one end of the second film is bonded to the other side of the pre-bonding area in the thickness direction, so that the remaining portion of the second film is located on a side of the pre-bonding area close to the welding area and separated from the welding area;

[0040] The step of partially overlapping the outer tab and the dummy tab group in the thickness direction of the body to form the overlapping portion comprises the steps of: overlapping the welding area and the dummy tab group in the thickness direction of the body to form the overlapping portion;

[0041] The step of welding the outer tab to the plurality of dummy tabs in the dummy tab group comprises the steps of: welding the welding area to the plurality of dummy tabs in the dummy tab group;

[0042] After welding the welding area to the multiple fake tabs in the fake tab group, the remaining part of the first film is pasted on one side of the overlapping part, and the remaining part of the second film is pasted on the other side of the overlapping part, and the first film and the second film are pasted to each other on both sides of the width direction of the overlapping part.

[0043] In some embodiments of the present application, the step of affixing the remaining portion of the first film to one side of the overlapping portion, affixing the remaining portion of the second film to the other side of the overlapping portion, and affixing the first film and the second film to each other on both sides of the overlapping portion in the width direction includes the following steps:

[0044] The pushing member is brought into contact with a side of the first film away from the outer tab;

[0045] The pushing member contacts the side of the second film away from the outer tab;

[0046] The pushing member is moved in the direction from the pre-gluing area to the welding area to push the remaining part of the first film to be glued to one side of the overlapping part, push the remaining part of the second film to be glued to the other side of the overlapping part, and make the first film and the second film glued to each other on both sides of the width direction of the overlapping part.

[0047] In some embodiments of the present application, the step of welding the outer tab to the plurality of dummy tabs in the dummy tab group comprises the following steps:

[0048] The outer tab is welded to the plurality of dummy tabs in the dummy tab group by laser welding or ultrasonic welding.

[0049] A lithium-ion battery provided in an embodiment of a third aspect of the present application includes:

[0050] The packaging shell comprises two mutually buckled shells, with a receiving cavity defined between the two shells;

[0051] In the battery cell provided by any embodiment of the first aspect of the present application, the body is accommodated in the accommodating cavity, the tab glue is clamped between the two shells, and part of the outer tab extends to the outside of the packaging shell.

[0052] A lithium-ion battery provided in an embodiment of the third aspect of the present application has at least the following beneficial effects:

[0053] A lithium-ion battery provided in an embodiment of the third aspect of the present application includes a battery cell provided in an embodiment of the first aspect of the present application. In the battery cell, the tab glue is wrapped around the overlapping portion formed by the overlap of the outer tab and the dummy tab group. Compared with the related art in which the tab glue is arranged on the outer tab, the distance between the tab glue and the body of the battery cell provided in the embodiment of the first aspect of the present application is closer. During the manufacturing process of the lithium-ion battery provided in the embodiment of the third aspect of the present application, there is no need to fold the dummy tab. After the battery cell is placed in the packaging shell, the top sealing process can be performed directly at the position where the tab glue is located. This can not only reduce the space occupied by the tab assembly between the body and the top sealing position, thereby improving the energy density of the lithium-ion battery, but also simplify the production steps of the lithium-ion battery, thereby improving the production efficiency of the lithium-ion battery.

[0054] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The present application is further described below with reference to the accompanying drawings and embodiments, wherein:

[0056] FIG1 is a schematic diagram of a lithium-ion battery in the related art;

[0057] FIG2 is a front view of a lithium-ion battery provided by some embodiments of the third aspect of the present application, including the battery cells provided by some embodiments of the first aspect of the present application;

[0058] FIG3 is a schematic diagram of the main body, dummy tab assembly, and outer tab of the battery cell shown in FIG2 ;

[0059] FIG4 is a schematic diagram of the battery body, dummy tab assembly, outer tabs, and tab glue of the battery cell shown in FIG2 ;

[0060] FIG5 is a schematic diagram of the battery body, the dummy tab assembly, the outer tabs, the tab glue, and the packaging shell of the battery cell shown in FIG4 ;

[0061] FIG6 is a schematic diagram of a battery cell body, a dummy tab assembly, an outer tab, and tab glue provided by other embodiments of the first aspect of the present application;

[0062] FIG7 is a cross-sectional view of the battery body, the dummy tab assembly, the outer tabs, the tab glue, and the packaging shell of the battery cell shown in FIG6 , taken along the AA section;

[0063] FIG8 is a schematic diagram of a battery cell body, a dummy tab assembly, an outer tab, and tab glue provided by some other embodiments of the first aspect of the present application;

[0064] FIG9 is a cross-sectional view of the battery body, the dummy tab assembly, the outer tabs, the tab glue, and the packaging shell of the battery cell shown in FIG8 at the BB section;

[0065] FIG10 is a schematic flow chart of a lithium-ion battery manufacturing method provided by some embodiments of the second aspect of the present application;

[0066] FIG11 is a schematic diagram of a battery cell after step S450 in the lithium-ion battery manufacturing method provided by some embodiments of the second aspect of the present application is completed;

[0067] FIG12 is a side view of the battery cell shown in FIG11 .

[0068] Figure markings: battery cells 100, 100', main body 110, 110', first pole piece 111, second pole piece 112, tab assembly 120, 120', dummy tab group 121, 121', dummy tab 1211, outer tab 122, 122', exposed area 1221, pre-pasting area 1222, welding area 1223, tab glue 123, 123', first film 1231, second film 1232, overlapping part 124, packaging shell 200, 200', shell 210, 210', pushing member 300. DETAILED DESCRIPTION

[0069] The following describes in detail embodiments of the present application. 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 application and are not to be construed as limiting the present application.

[0070] In the description of this application, it should be understood that descriptions involving orientation, such as up, down, 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 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. Therefore, they cannot be understood as limitations on this application.

[0071] In the description of this application, 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 this application based on the specific content of the technical solution.

[0072] Throughout the description of this application, reference to terms such as "one embodiment" or "some embodiments" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of this application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0073] Lithium-ion batteries, due to their high specific energy, low self-discharge, lightweight, and environmentally friendly advantages, are widely used in 3C digital products such as mobile phones, mobile power supplies, and smart wearables, as well as in energy storage for solar street lights and power batteries for new energy vehicles. Battery cell 100 is widely used due to its high charge rate. The main body 110 of battery cell 100 is connected to multiple dummy tabs. During the manufacturing process, the dummy tabs must first be pre-welded, and then the outer tabs are welded to the dummy tabs. Finally, the battery cell 100 is placed in a packaging shell, with the main body 110 and the dummy tabs located inside the shell and the outer tabs extending outside.

[0074] Referring to Figure 1, in order to more clearly illustrate the structure of the battery cell 100' in the related art, the shell 210' is processed in perspective. In the tab assembly 120' of the battery cell 100', the tab glue 123' is set on the outer tab 122', and the outer tab 122' is welded to the dummy tab group 121'. Along the length direction of the outer tab 122', the tab glue 123' and the dummy tab 121' are spaced apart. After the battery cell 100' is placed in the packaging shell 200', the tab glue 123' is clamped between the two shells 210' of the packaging shell 200', and then the edge where the tab glue 123' is located is top-sealed to form a sealed connection between the two shells 210' and the tab glue 123'. Due to the distance between the tab glue 123' and the fake tab group 121', the fake tab group 121' occupies a larger space between the main body 110' and the tab glue 123', resulting in a lower energy density of the lithium-ion battery; in order to reduce the space occupied by the fake tab group 121', the fake tab group 121' can be folded before the battery cell 100' is put into the shell, but this will increase the production steps of the lithium-ion battery and lead to lower production efficiency. In addition, the folded fake tab group 121' still occupies a certain space in the lithium-ion battery, resulting in a lower energy density.

[0075] Based on this, referring to FIG2 , in order to more clearly illustrate the structure of the battery cell 100 provided by the embodiment of the first aspect of the present application, the housing 210 is perspectively processed. The embodiment of the first aspect of the present application provides a battery cell 100, including a body 110 and a tab assembly 120. Two tab assemblies 120 are provided, and the two tab assemblies 120 are staggered in the width direction of the body 110. Referring to FIG4 to FIG9 , the tab assembly 120 includes a dummy tab group 121, an outer tab 122, and a tab glue 123. The dummy tab group 121 includes at least one dummy tab 1211 connected to the body 110. The outer tab 122 is electrically connected to the dummy tab group 121. Referring to FIG3 , in a projection along the thickness direction of the body 110, the outer tab 122 and the dummy tab group 121 partially overlap to form an overlapping portion 124, and the tab glue 123 wraps around at least a portion of the overlapping portion 124.

[0076] In a battery cell 100 provided in an embodiment of the first aspect of the present application, the tab glue 123 is wrapped around an overlapping portion 124 formed by the overlap of the outer tab 122 and the dummy tab group 121. Compared with the related art in which the tab glue 123 is arranged on the outer tab 122, the distance between the tab glue 123 and the main body 110 of the battery cell 100 provided in the embodiment of the first aspect of the present application is closer. When the battery cell 100 is applied to a lithium-ion battery, there is no need to fold the dummy tab 1211 during the manufacturing process. After the battery cell 100 is placed in the packaging shell 200, the top sealing process can be performed directly at the position where the tab glue 123 is located. This can not only reduce the space occupied by the tab assembly 120 between the main body 110 and the top sealing position, thereby improving the energy density of the lithium-ion battery, but also simplify the production steps of the lithium-ion battery, thereby improving the production efficiency of the lithium-ion battery.

[0077] The tab glue 123 can have various structural forms. For example, in some embodiments, referring to Figures 4 and 5, the tab glue 123 is an integrated structure, which can be formed by injection molding. After the battery cell 100 is placed in the packaging shell 200, the integrated tab glue 123 can more reliably wrap the overlapping portion 124, thereby reducing the possibility of the outer tab 122 and the dummy tab assembly 121 directly contacting the packaging shell 200, thereby reducing the possibility of a short circuit in the battery cell 100, thereby improving the safety performance of the lithium-ion battery.

[0078] In other embodiments, referring to Figures 6, 7, 8, and 9, the tab adhesive 123 includes a first adhesive sheet 1231 and a second adhesive sheet 1232. The first adhesive sheet 1231 and the second adhesive sheet 1232 are disposed on opposite sides of the overlapping portion 124 in the thickness direction, and the first adhesive sheet 1231 and the second adhesive sheet 1232 are bonded to each other on opposite sides of the overlapping portion 124 in the width direction. The tab adhesive 123 includes the first adhesive sheet 1231 and the second adhesive sheet 1232 in separate pieces. During the production process of the battery cell 100, after the outer tab 122 is connected to the dummy tab assembly 121, the first adhesive sheet 1231 and the second adhesive sheet 1232 are respectively bonded to opposite sides of the overlapping portion 124, and the first adhesive sheet 1231 and the second adhesive sheet 1232 are bonded to each other on opposite sides of the overlapping portion 124 in the width direction. This simplifies the assembly process and improves the production efficiency of the battery cell 100.

[0079] There are also various situations in which the tab glue 123 is provided. At least part of the tab glue 123 can be wrapped around at least part of the overlapping portion 124. Optionally, referring to Figures 5, 7, and 9, the tab glue 123 is wrapped around the end of the dummy tab group 121 away from the body 110. After the battery cell 100 is placed in the packaging shell 200, the dummy tab group 121 will not be exposed outside the packaging shell 200, which is conducive to improving the neatness of the appearance of the lithium-ion battery and can avoid the presence of gaps between adjacent dummy tabs 1211, which causes the inside of the packaging shell 200 to communicate with the outside, thereby improving the sealing of the packaging shell 200.

[0080] For example, in some embodiments, referring to Figures 4 and 5, an integrated structure of the tab glue 123 can be provided to wrap around one end of the fake tab group 121 away from the main body 110; in other embodiments, referring to Figures 8 and 9, the tab glue 123 includes a first film 1231 and a second film 1232, and the first film 1231 and the second film 1232 are respectively arranged on both sides of the overlapping portion 124 in the thickness direction, and the first film 1231 and the second film 1232 are bonded to each other on both sides in the width direction of the overlapping portion 124, and one end of the first film 1231 in the length direction of the overlapping portion 124 is bonded to one side of the outer tab 122 in the thickness direction of the overlapping portion 124, and one end of the second film 1232 in the length direction of the overlapping portion 124 is bonded to the other side of the outer tab 122 in the thickness direction of the overlapping portion 124.

[0081] The dimensions of the tab glue 123 along the length, width, and thickness of the body 110 can be set according to actual needs. For example, in some embodiments, referring to Figures 4 to 9, the dimension L of the tab glue 123 along the length of the body 110 can be set to 0.5 mm to 10 mm; the dimension W of the tab glue 123 along the width of the body 110 can be set to 1 mm to 25 mm; and the dimension D of the tab glue 123 along the thickness of the body 110 can be set to 0.002 mm to 0.5 mm.

[0082] Further, referring to Figures 5, 7, and 9, the dummy tab group 121 includes a plurality of dummy tabs 1211, which are arranged in sequence along the thickness direction of the body 110. Providing a plurality of dummy tabs 1211 is beneficial for reducing the internal resistance of the battery cell 100 and increasing the output current of the battery cell 100. The plurality of dummy tabs 1211 in the same dummy tab group 121 are arranged in sequence along the thickness direction of the body 110. Furthermore, the projections of the plurality of dummy tabs 1211 in the thickness direction of the body 110 overlap. During installation, the plurality of dummy tabs 1211 and the outer tab 122 can be clamped in the thickness direction of the body 110 by a fixture, so that the outer tab 122 and the plurality of dummy tabs 1211 are tightly fitted in the thickness direction of the body 110, and then the outer tab 122 and the plurality of dummy tabs 1211 are welded together. The projections of the multiple inner tabs 321 in the same inner tab group 320 in the thickness direction of the body 110 are arranged to overlap. By only welding the overlapping portion 124 once, the multiple dummy tabs 1211 in the same dummy tab group 121 can be welded to the outer tab 122, which is conducive to simplifying the production steps and improving production efficiency.

[0083] In some embodiments, the body 110 includes a first electrode piece 111 and a second electrode piece 112, wherein the dummy electrode piece 1211 in one dummy electrode piece group 121 is connected to the first electrode piece 111, and the dummy electrode piece 1211 in another dummy electrode piece group 121 is connected to the second electrode piece 112. In the scheme where the dummy electrode piece group 121 includes multiple dummy electrode pieces 1211, the multiple dummy electrode pieces 1211 in one dummy electrode piece group 121 are all connected to the first electrode piece 111, and the multiple dummy electrode pieces 1211 in the other dummy electrode piece group 121 are all connected to the second electrode piece 112. The first electrode piece 111 and the second electrode piece 112 are stacked and wound to form a wound structure battery cell 100, which has a relatively simple structure, is easy to manufacture, and has high production efficiency.

[0084] In other embodiments, the body 110 includes a plurality of first pole pieces 111 and a plurality of second pole pieces 112, wherein the plurality of dummy pole pieces 1211 in one dummy pole piece group 121 are connected to the plurality of first pole pieces 111 in a one-to-one correspondence, and the plurality of dummy pole pieces 1211 in another dummy pole piece group 121 are connected to the plurality of second pole pieces 112 in a one-to-one correspondence. The plurality of first pole pieces 111 and the plurality of second pole pieces 112 are alternately stacked to form a laminated structure battery cell 100, which has a low internal resistance and is conducive to high current charging and discharging.

[0085] 10 , a method for manufacturing a lithium-ion battery provided in an embodiment of the second aspect of the present application is used to manufacture a lithium-ion battery including the multi-electrode battery provided in any embodiment of the first aspect of the present application. The method for manufacturing a lithium-ion battery includes the following steps:

[0086] S100, obtaining or preparing a combination of the main body 110 and the dummy tab group 121;

[0087] S200 , partially overlapping the outer tab 122 and the dummy tab assembly 121 in the thickness direction of the body 110 to form an overlapping portion 124 ;

[0088] S300, welding the outer tab 122 to the plurality of dummy tabs 1211 in the dummy tab group 121;

[0089] S400 , forming the tab glue 123 on the overlapping portion 124 to form the battery cell 100 ;

[0090] S500 , taking or preparing a packaging shell 200 , placing the battery cell 100 into the packaging shell 200 , and sandwiching the tab glue 123 between the two shells 210 of the packaging shell 200 .

[0091] In the lithium-ion battery manufacturing method provided by the second embodiment of the present application, the battery cell 100 provided by the first embodiment of the present application is first prepared, and the tab glue 123 is wrapped on the overlapping portion 124 formed by the overlap of the outer tab 122 and the dummy tab group 121. Compared with the related art in which the tab glue 123 is set on the outer tab 122, the distance between the tab glue 123 and the main body 110 of the battery cell 100 provided by the first embodiment of the present application is closer. After the battery cell 100 is prepared, there is no need to fold the dummy tab 1211. After the battery cell 100 is placed in the packaging shell 200, the top sealing process is directly performed at the position where the tab glue 123 is located to complete the manufacture of the lithium-ion battery. On the one hand, the space occupied by the tab assembly 120 between the main body 110 and the top sealing position is small, which can improve the energy density of the lithium-ion battery. On the other hand, the production steps of the lithium-ion battery are relatively simple, which can improve the production efficiency of the lithium-ion battery.

[0092] The specific steps of S400 can be designed according to the structure of the tab glue 123. For example, in some embodiments, S400 includes the following steps:

[0093] S410, after the outer tabs 122 are welded to the multiple dummy tabs 1211 in the dummy tab group 121, the overlapping portion 124 is placed in an injection mold, plastic material is injected into the injection mold and solidified to form tab glue 123 wrapped around the overlapping portion 124, forming the battery cell 100 as shown in Figures 4 and 5.

[0094] Through step S410, an integrated structure of the tab glue 123 wrapped around the overlapping portion 124 can be formed. After the battery cell 100 is placed in the packaging shell 200, the integrated structure of the tab glue 123 can more reliably wrap the overlapping portion 124, thereby reducing the possibility of the outer tab 122 and the fake tab group 121 directly contacting the packaging shell 200 and causing a short circuit in the battery cell 100, which is beneficial to improving the safety performance of the lithium-ion battery.

[0095] In some other embodiments, S400 includes the steps of:

[0096] S420, taking or preparing a first film 1231 and a second film 1232;

[0097] S430, after welding the outer tab 122 to the multiple dummy tabs 1211 in the dummy tab group 121, stick the first film 1231 on one side of the overlapping portion 124 in the thickness direction, stick the second film 1232 on the other side of the overlapping portion 124 in the thickness direction, and stick the first film 1231 and the second film 1232 to each other on both sides of the overlapping portion 124 in the width direction to form the battery cell 100 as shown in Figures 6 and 7.

[0098] After the outer tab 122 is connected to the fake tab group 121, the first film 1231 and the second film 1232 in separate forms are respectively pasted on both sides of the overlapping portion 124 through steps S420 and S430, and the first film 1231 and the second film 1232 are bonded to each other on both sides of the overlapping portion 124 in the width direction, so that the tab glue 123 wrapped in the overlapping portion 124 can be formed. The assembly process is relatively simple, which is conducive to improving the production efficiency of the battery cell 100.

[0099] In some further embodiments, S400 includes the steps of:

[0100] S440, taking or preparing the first film 1231 and the second film 1232;

[0101] S450, referring to Figures 11 and 12, the outer tab 122 includes an exposed area 1221, a pre-bonding area 1222, and a welding area 1223 sequentially connected along its length. One end of the first film 1231 is bonded to one side of the pre-bonding area 1222 in the thickness direction, so that the remaining portion of the first film 1231 is located on a side of the pre-bonding area 1222 close to the welding area 1223 and separated from the welding area 1223. One end of the second film 1232 is bonded to the other side of the pre-bonding area 1222 in the thickness direction, so that the remaining portion of the second film 1232 is located on a side of the pre-bonding area 1222 close to the welding area 1223 and separated from the welding area 1223.

[0102] S200 includes the steps of: overlapping the welding area 1223 and the dummy tab assembly 121 in the thickness direction of the body 110 to form an overlapping portion 124;

[0103] S300 includes the steps of: welding the welding area 1223 to the plurality of dummy tabs 1211 in the dummy tab group 121;

[0104] S460, after welding the welding area 1223 to the multiple fake tabs 1211 in the fake tab group 121, paste the remaining first film 1231 on one side of the overlapping portion 124, and paste the remaining second film 1232 on the other side of the overlapping portion 124, and paste the first film 1231 and the second film 1232 on both sides of the overlapping portion 124 in the width direction to form the battery cell 100 as shown in Figures 8 and 9.

[0105] Through steps S440, S450 and S460, the tab glue 123 can be wrapped around the end of the fake tab group 121 away from the main body 110. After the battery cell 100 is placed in the packaging shell 200, the fake tab group 121 will not be exposed outside the packaging shell 200, which is beneficial to improving the neatness of the appearance of the lithium-ion battery, and can avoid the presence of gaps between adjacent fake tabs 1211, which causes the inside and outside of the packaging shell 200 to be connected, which is beneficial to improving the sealing of the packaging shell 200.

[0106] Further, referring to FIG. 12 , S450 includes the steps of:

[0107] S451 , making the pushing member 300 contact the side of the first film 1231 away from the outer tab 122 ;

[0108] S452 , making the pushing member 300 contact the side of the second film 1232 away from the outer tab 122 ;

[0109] S453, moves the pushing member 300 along the direction from the pre-pasting area 1222 to the welding area 1223 to push the remaining part of the first film 1231 to be pasted on one side of the overlapping part 124, pushes the remaining part of the second film 1232 to be pasted on the other side of the overlapping part 124, and makes the first film 1231 and the second film 1232 stick to each other on both sides of the width direction of the overlapping part 124.

[0110] The pusher 300 is used to push the first film 1231 and the second film 1232 to adhere to both sides of the overlapping portion 124. The pusher 300 can straighten the first film 1231 and the second film 1232 during the pushing process, thereby reducing the possibility of wrinkles on the first film 1231 and the second film 1232, thereby improving the adhesion quality of the tab glue 123. Specifically, the pusher 300 is a push block or a brush, and can be driven by a robotic arm, a motor, a cylinder, etc. to move the pusher 300 relative to the outer tab 122.

[0111] Furthermore, S300 includes the steps of:

[0112] The outer tab 122 is welded to the plurality of dummy tabs 1211 in the dummy tab group 121 by laser welding or ultrasonic welding.

[0113] Laser welding is faster and produces less deformation, which is beneficial to improving production efficiency and welding quality; ultrasonic welding consumes less power, has higher weld strength, and has lower requirements for surface cleanliness at the weld, which is beneficial to reducing production costs and improving welding quality.

[0114] A lithium-ion battery provided in an embodiment of the third aspect of the present application includes a packaging shell 200 and a battery cell 100 provided in any embodiment of the first aspect of the present application. The packaging shell 200 includes two shells 210 that are interlocked with each other, and a accommodating cavity is defined between the two shells 210. Specifically, in some embodiments, both shells 210 can be provided with grooves. After the two shells 210 are interlocked, the two grooves together constitute the accommodating cavity. In other embodiments, only one of the shells 210 can be provided with a groove, and the other shell 210 is flat-plate-shaped. The flat-plate-shaped shell 210 is covered on the shell 210 with the groove, and the single groove constitutes the accommodating cavity; the body 110 is accommodated in the accommodating cavity, the tab glue 123 is clamped between the two shells 210, and part of the outer tab 122 extends to the outside of the packaging shell 200.

[0115] A lithium-ion battery provided in an embodiment of the third aspect of the present application includes a battery cell 100 provided in an embodiment of the first aspect of the present application. In the battery cell 100, the tab glue 123 is wrapped around the overlapping portion 124 formed by the overlap of the outer tab 122 and the dummy tab group 121. Compared with the related art in which the tab glue 123 is arranged on the outer tab 122, the distance between the tab glue 123 and the main body 110 of the battery cell 100 provided in the embodiment of the first aspect of the present application is closer. During the manufacturing process of the lithium-ion battery provided in the embodiment of the third aspect of the present application, there is no need to fold the dummy tab 1211. After the battery cell 100 is placed in the packaging shell 200, the top sealing process can be performed directly at the position where the tab glue 123 is located. This can not only reduce the space occupied by the tab assembly 120 between the main body 110 and the top sealing position, thereby improving the energy density of the lithium-ion battery, but also simplify the production steps of the lithium-ion battery, thereby improving the production efficiency of the lithium-ion battery.

[0116] The embodiments of the present application have been described in detail above with reference to the accompanying drawings. However, the present application is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the purpose of the present application. In addition, the embodiments of the present application 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, Comprising: A body; An ear assembly, including a dummy ear group, an external ear, and ear glue. The dummy ear group includes at least one dummy ear connected to the body. The external ear is electrically connected to the dummy ear group. In the projection along the thickness direction of the body, the external ear and the dummy ear group partially overlap to form an overlapping portion. The ear glue wraps around at least part of the overlapping portion. There are two ear assemblies, and the two ear assemblies are staggeredly arranged in the width direction of the body.

2. The cell according to claim 1, characterized in that, The ear glue includes a first film and a second film. The first film and the second film are respectively disposed on both sides of the overlapping portion in the thickness direction, and the first film and the second film are adhesively bonded to each other on both sides of the overlapping portion in the width direction.

3. The battery cell according to claim 2, wherein, One end of the first film in the length direction of the overlapping portion is adhesively bonded to one side of the external ear in the thickness direction of the overlapping portion, and one end of the second film in the length direction of the overlapping portion is adhesively bonded to the other side of the external ear in the thickness direction of the overlapping portion.

4. The battery cell according to claim 1, wherein, The ear glue is of an integral structure.

5. The battery cell according to claim 1, characterized in that, The ear glue wraps around the end of the dummy ear group away from the body.

6. The cell according to claim 1, wherein The dummy ear group includes a plurality of dummy ears, and the plurality of dummy ears are arranged in sequence along the thickness direction of the body.

7. The battery cell according to claim 1 or 6, characterized in that, The body includes a first pole piece and a second pole piece. The first pole piece and the second pole piece are laminated and wound. The dummy ears in one of the dummy ear groups are connected to the first pole piece, and the dummy ears in the other dummy ear group are connected to the second pole piece.

8. The battery cell according to claim 6, characterized in that, The body includes a plurality of first pole pieces and a plurality of second pole pieces. The plurality of first pole pieces and the plurality of second pole pieces are alternately laminated. The plurality of dummy ears in one of the dummy ear groups are correspondingly connected to the plurality of first pole pieces one by one, and the plurality of dummy ears in the other dummy ear group are correspondingly connected to the plurality of second pole pieces one by one.

9. The cell according to claim 1, characterized in that, The dimension of the ear glue along the length direction of the body is 0.5 mm to 10 mm; And / or, The dimension of the ear glue along the width direction of the body is 1 mm to 25 mm; And / or, The dimension of the ear glue along the thickness direction of the body is 0.002 mm to 0.5 mm.

10. A method for manufacturing a lithium-ion battery, characterized in that, A lithium-ion battery for manufacturing a battery cell as described in any one of claims 1 to 9. The manufacturing method of the lithium-ion battery includes the steps of: Taking or preparing a combination of the body and the dummy ear group; Making the external ear and the dummy ear group partially overlap in the thickness direction of the body to form the overlapping portion; Welding the external ear to the plurality of dummy ears in the dummy ear group; Making the ear glue on the overlapping portion to form a battery cell; Taking or preparing a packaging case, placing the battery cell into the packaging case, and clamping the ear glue between two casings of the packaging case.

11. The method for manufacturing a lithium ion battery according to claim 10, wherein, The step of making the ear glue on the overlapping portion includes the steps of: After welding the external ear to the plurality of dummy ears in the dummy ear group, placing the overlapping portion into an injection mold, injecting a plastic material into the injection mold, and curing to form the ear glue that wraps around the overlapping portion.

12. The method for manufacturing a lithium-ion battery according to claim 10, wherein Manufacturing the tab glue on the overlapping portion includes the steps of: Taking or preparing a first film and a second film; After welding the external tab to a plurality of the dummy tabs in the dummy tab group, pasting the first film on one side of the overlapping portion in the thickness direction, pasting the second film on the other side of the overlapping portion in the thickness direction, and causing the first film and the second film to be pasted to each other on both sides in the width direction of the overlapping portion.

13. The method for manufacturing a lithium-ion battery according to claim 10, wherein, Manufacturing the tab glue on the overlapping portion includes the steps of: Taking or preparing a first film and a second film; The external tab includes an exposed area, a pre-pasting area, and a welding area that are sequentially connected along its length direction. One end of the first film is pasted on one side of the pre-pasting area in the thickness direction, so that the remaining part of the first film is located on the side of the pre-pasting area close to the welding area and is separated from the welding area. One end of the second film is pasted on the other side of the pre-pasting area in the thickness direction, so that the remaining part of the second film is located on the side of the pre-pasting area close to the welding area and is separated from the welding area; Causing the external tab and the dummy tab group to partially overlap in the thickness direction of the body to form the overlapping portion includes the steps of: causing the welding area and the dummy tab group to overlap in the thickness direction of the body to form the overlapping portion; Welding the external tab to a plurality of the dummy tabs in the dummy tab group includes the steps of: welding the welding area to a plurality of the dummy tabs in the dummy tab group; After welding the welding area to a plurality of the dummy tabs in the dummy tab group, pasting the remaining part of the first film on one side of the overlapping portion, pasting the remaining part of the second film on the other side of the overlapping portion, and causing the first film and the second film to be pasted to each other on both sides in the width direction of the overlapping portion.

14. The method for manufacturing a lithium ion battery according to claim 13, wherein Pasting the remaining part of the first film on one side of the overlapping portion, pasting the remaining part of the second film on the other side of the overlapping portion, and causing the first film and the second film to be pasted to each other on both sides in the width direction of the overlapping portion includes the steps of: Causing a pushing member to contact the side of the first film away from the external tab; Causing a pushing member to contact the side of the second film away from the external tab; Causing the pushing member to move along the direction from the pre-pasting area to the welding area to push the remaining part of the first film to be pasted on one side of the overlapping portion, push the remaining part of the second film to be pasted on the other side of the overlapping portion, and cause the first film and the second film to be pasted to each other on both sides in the width direction of the overlapping portion.

15. The manufacturing method of a lithium-ion battery according to claim 10, characterized in that, Welding the external tab to a plurality of the dummy tabs in the dummy tab group includes the steps of: Welding the external tab to a plurality of the dummy tabs in the dummy tab group by means of laser welding or ultrasonic welding.

16. A lithium-ion battery, characterized in that, Including: A packaging shell, including two mutually buckled shells, and an accommodation cavity is defined between the two shells; The battery cell according to any one of claims 1 to 9, wherein the body is received in the receiving cavity, the tab glue is clamped between the two housings, and a part of the external tab extends to the outside of the packaging case.

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