Battery cell components, single cells and internal series batteries

Abstract

The utility model discloses a battery cell assembly, a single battery cell and an internal series battery, wherein the battery cell assembly includes a bare battery cell and a partition; the bare battery cell includes a bare battery cell body and a pole ear unit connected to the side of the bare battery cell body, the bare battery cell body and the partition are stacked, and a side of the partition close to the bare battery cell body is provided with an avoidance groove staggered with the bare battery cell body; wherein the pole ear unit includes a fake pole ear and a pole ear, one end of the fake pole ear is connected to the side of the bare battery cell body, the fake pole ear is bent and extends to the inside of the avoidance groove, and the pole ear is engaged with the part of the fake pole ear extending into the avoidance groove and extends to the outside of the avoidance groove. In the battery cell assembly of the utility model, the fake pole ear extending into the avoidance groove is used to connect with the pole ear, and compared with the straight-out fake pole ear, the space occupied by the pole ear unit in the longitudinal direction of the battery cell can be reduced, which is beneficial to improving the utilization rate of the longitudinal space of the battery cell and improving the energy density.

Description

Technical Field

[0001] The utility model relates to the technical field of power storage devices, in particular to a battery core assembly, a single battery core and an internal series battery. Background Art

[0002] At present, most chemical power sources are difficult to exceed 5V due to chemical system limitations, but many electrical devices require voltages exceeding 5V. Therefore, multiple chemical power sources need to be connected in series to increase the voltage.

[0003] Among them, the external series connection method is prone to poor welding problems due to the need to weld multiple battery cells in series, and multiple battery cells in series are also prone to electrical performance mismatch problems; the internal series connection method can greatly reduce the number of welding times and improve battery consistency, but the internal series battery needs to be half the original thickness. Thinner batteries reduce the space for folding the pole ears and increase the difficulty of folding the pole ears. If the straight-out method is used, the utilization rate of the longitudinal space of the battery cell will be reduced, affecting the energy density of the battery. Utility Model Content

[0004] 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 assembly that can improve the energy density of the battery.

[0005] The utility model also provides a single cell and an internally connected battery having the cell assembly.

[0006] According to the battery cell assembly of the first aspect embodiment of the utility model, the battery cell assembly includes a bare battery cell and a partition; the bare battery cell includes a bare battery cell body, and a pole ear unit connected to the side of the bare battery cell body, the bare battery cell body and the partition are stacked, and the side of the partition close to the bare battery cell body is provided with an avoidance groove staggered with the bare battery cell body; wherein the pole ear unit includes a dummy pole ear and a pole ear, one end of the dummy pole ear is connected to the side of the bare battery cell body, the dummy pole ear is bent and extends to the inside of the avoidance groove, and the pole ear is joined to the part of the dummy pole ear extending into the avoidance groove and extends to the outside of the avoidance groove.

[0007] The battery cell assembly according to the embodiment of the utility model has at least the following beneficial effects:

[0008] In the battery cell assembly of the utility model, by arranging an avoidance groove on one side of the partition close to the bare battery cell body, the dummy pole ear can be bent and extended into the avoidance groove, thereby changing the extension direction of the dummy pole ear, and the dummy pole ear extended into the avoidance groove is connected with the pole ear. Compared with the straight-out dummy pole ear, the space occupied by the pole ear unit in the longitudinal direction of the battery cell can be reduced, which is beneficial to improving the utilization rate of the longitudinal space of the battery cell and improving the energy density.

[0009] According to some embodiments of the present invention, a side of the bare cell body close to the partition is defined as a reference plane, the dummy pole ear extends from the bare cell body toward the avoidance groove and exceeds the reference plane, the length of the portion of the dummy pole ear exceeding the reference plane in a preset direction is less than or equal to the depth of the avoidance groove, and the depth of the avoidance groove is less than or equal to the thickness of the bare cell;

[0010] Wherein, the preset direction is perpendicular to the reference plane.

[0011] According to some embodiments of the utility model, a side of the partition away from the bare battery cell is provided with a protrusion opposite to the notch of the avoidance groove, and the avoidance groove extends into the protrusion.

[0012] According to some embodiments of the present invention, the partition includes an aluminum layer and protective layers respectively arranged on both sides of the aluminum layer, and the thickness of the aluminum layer is less than or equal to 30 μm and greater than or equal to 50 μm.

[0013] According to some embodiments of the utility model, the pole tab is welded to the dummy pole tab;

[0014] Wherein, the width of the avoidance groove is T, the thickness of the weld mark formed by welding the pole tab and the fake pole tab is B, and the thickness of the pole tab is C;

[0015] in,

[0016] According to some embodiments of the present invention, the pole lug is also engaged with a dummy pole lug that does not extend into the avoidance groove.

[0017] According to some embodiments of the present invention, the position of the junction between the dummy pole tab and the bare cell body is opposite to the position of the avoidance groove.

[0018] According to some embodiments of the utility model, the bare cells are arranged on both sides of the partition, and the avoidance grooves are arranged on both sides of the partition;

[0019] One of the bare cells is a first bare cell, and the other bare cell is a second bare cell; the avoidance groove provided on the side of the partition close to the first bare cell is a first avoidance groove, and the avoidance groove provided on the side of the partition close to the second bare cell is a second avoidance groove;

[0020] The dummy pole ear on the first bare battery cell is bent and extends into the first avoidance groove, and the pole ear on the first bare battery cell is joined with the part of the dummy pole ear on the first bare battery cell extending into the first avoidance groove, and extends to the outside of the first avoidance groove; the dummy pole ear on the second bare battery cell is bent and extends into the second avoidance groove, and the pole ear on the second bare battery cell is joined with the part of the dummy pole ear on the second bare battery cell extending into the second avoidance groove, and extends to the outside of the second avoidance groove.

[0021] According to the second aspect of the present invention, a single cell comprises: a cell assembly as described above; an outer film, wherein the outer film forms an inner cavity; wherein the cell assembly is arranged inside the inner cavity, the bare cell body is located inside the inner cavity and is spaced apart from one of the side walls of the inner cavity to form a gap, and the avoidance groove is located in the gap.

[0022] The single cell according to the embodiment of the utility model has at least the following beneficial effects:

[0023] In the single-cell battery of the utility model, the battery cell assembly is provided with an avoidance groove on one side of the partition close to the bare battery cell body, so that the dummy pole ear can be bent and extended into the avoidance groove, thereby changing the extension direction of the dummy pole ear, and the dummy pole ear extending into the avoidance groove is connected with the pole ear. Compared with the straight-out dummy pole ear, the space occupied by the pole ear unit in the longitudinal direction of the battery cell can be reduced, which is beneficial to improving the utilization rate of the longitudinal space of the battery cell and improving the energy density.

[0024] The internal series battery according to the embodiment of the third aspect of the utility model includes the battery cell assembly as described above; or includes the single battery cell as described above.

[0025] The internal series battery according to the embodiment of the utility model has at least the following beneficial effects:

[0026] In the internal series battery of the utility model, the battery cell assembly is provided with an avoidance groove on one side of the partition close to the bare battery cell body, so that the dummy pole ear can be bent and extended into the avoidance groove, thereby changing the extension direction of the dummy pole ear, and the dummy pole ear extending into the avoidance groove is connected with the pole ear. Compared with the straight-out type dummy pole ear, the space occupied by the pole ear unit in the longitudinal direction of the battery cell can be reduced, which is beneficial to improving the utilization rate of the longitudinal space of the battery cell and improving the energy density.

[0027] 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

[0028] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0029] Figure 1 This is a schematic diagram of the three-dimensional structure of a battery cell assembly according to an embodiment of the utility model;

[0030] Figure 2 This is a schematic diagram of the top view of the battery cell assembly of one embodiment of the utility model;

[0031] Figure 3 for Figure 2 The figure shown is a schematic diagram of the cross-sectional structure along the AA section;

[0032] Figure 4 This is a schematic structural diagram of a bare battery cell according to an embodiment of the utility model;

[0033] Figure 5 This is a schematic structural diagram of a bare battery cell in another embodiment of the utility model;

[0034] Figure 6 It is a schematic diagram of the structure in which the false pole ear in the bare battery cell is a direct-out type;

[0035] Figure 7 for Figure 2 The figure shown is a schematic diagram of the cross-sectional structure along the BB section;

[0036] Figure 8 This is a schematic diagram of the explosion structure of a single battery cell according to an embodiment of the utility model;

[0037] Fig. 9 The figure is a schematic cross-sectional view of a single cell according to an embodiment of the present invention.

[0038] Figure Number:

[0039] 100, bare cell; 100a, first bare cell; 100b, second bare cell; 110, bare cell body; 111, cathode sheet; 112, anode sheet; 113, separator; 120, tab unit; 121, fake tab; 122, tab;

[0040] 200, partition; 210, avoidance groove; 220, protrusion;

[0041] 300, outer film; 300a, first aluminum-plastic film; 300b, second aluminum-plastic film; 310, inner cavity. DETAILED DESCRIPTION

[0042] 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.

[0043] In the description of the present utility model, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying 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 utility model. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] like Figure 1 As shown, a battery cell assembly provided in the present application is applied to an internal series battery, and the battery cell assembly includes a bare battery cell 100 and a separator 200 .

[0046] Combination Figure 2 and Figure 3 The bare cell 100 includes a bare cell body 110 and a tab unit 120 connected to a side of the bare cell body 110 .

[0047] Combination Figure 3 and Figure 4 Specifically, the bare cell body 110 includes an anode sheet 112, a cathode sheet 111 arranged parallel to the anode sheet 112, and a separator 113 arranged between the anode sheet 112 and the cathode sheet 111; the tab unit 120 includes an anode tab unit and a cathode tab unit, the anode tab unit is connected to the anode sheet 112, and the cathode tab unit is connected to the cathode sheet 111.

[0048] It should be noted that when the pole lug unit 120 is used for description below, the pole lug unit 120 may represent an anode lug unit or a cathode lug unit.

[0049] like Figure 4As shown, the pole lug unit 120 includes a dummy pole lug 121 and a pole lug 122 , wherein the dummy pole lug 121 is integrated with the pole piece, the dummy pole lug 121 is a part extending from the pole piece, and the pole lug 122 needs to be connected to the dummy pole lug 121 by welding or other methods.

[0050] Combination Figure 3 and Figure 4 The partition 200 is stacked with the bare cell body 110, and a side of the partition 200 close to the bare cell body 110 is provided with an avoidance groove 210 staggered from the bare cell body 110, that is, the avoidance groove 210 is opened on the side of the partition 200 close to the bare cell body 110, and the avoidance groove 210 is located next to the bare cell body 110 but not covered by the bare cell body 110; one end of the fake pole ear 121 is connected to the side of the bare cell body 110, the fake pole ear 121 is bent and extends to the inside of the avoidance groove 210, and the pole ear 122 is joined to the part of the fake pole ear 121 extending into the avoidance groove 210 and extends to the outside of the avoidance groove 210.

[0051] The position where the fake pole tab 121 is joined to the bare cell body 110 is opposite to the position of the avoidance groove 210 , so that the fake pole tab 121 can be extended into the avoidance groove 210 nearby after being bent.

[0052] It can be understood that, for the anode ear unit, all the anode sheets 112 extend the fake pole ears 121 (polarity is positive) toward the side of the bare battery body 110, and all the fake pole ears 121 (polarity is positive) are gathered together and then bent and extended into the avoidance groove 210, the pole ear 122 (polarity is positive) extends into the avoidance groove 210 and is engaged with the part of the fake pole ear 121 (polarity is positive) extending into the avoidance groove 210, and the pole ear 122 (polarity is positive) extends out of the avoidance groove 210 at one end away from the fake pole ear 121 (polarity is positive).

[0053] It can also be understood that, for the cathode ear unit, all the cathode sheets 111 extend the fake pole ears 121 (negative polarity) toward the side of the bare battery body 110, and all the fake pole ears 121 (negative polarity) are gathered together and then bent and extended into the avoidance groove 210, the pole ear 122 (negative polarity) extends into the avoidance groove 210 and is engaged with the part of the fake pole ear 121 (negative polarity) extending into the avoidance groove 210, and the pole ear 122 (negative polarity) extends out of the avoidance groove 210 at one end away from the fake pole ear 121 (negative polarity).

[0054] It should be noted that the connection between the tab 122 and the portion of the dummy tab 121 extending into the avoidance groove 210 does not mean that the tab 122 is only connected to the portion of the dummy tab 121 extending into the avoidance groove 210. In some cases, such as Figure 5As shown, the pole lug 122 is engaged with the portion of the dummy pole lug 121 extending into the avoidance groove 210 , and the pole lug 122 is also engaged with the portion of the dummy pole lug 121 not extending into the avoidance groove 210 .

[0055] Specifically, a portion of the pole tab 122 is arranged parallel to the bent dummy pole tab 121 , and the pole tab 122 is bent after extending from the avoidance groove 210 to remain parallel to the bare cell body 110 .

[0056] Combination Figure 2 , Figure 3 and Figure 7 In some embodiments, the dummy pole lugs 121 of the anode lug unit and the cathode lug unit extend into the same avoidance groove 210. In this way, one avoidance groove 210 can realize the requirement of bending the dummy pole lugs 121 of the anode lug unit and the cathode lug unit at the same time, and the processing is simple.

[0057] In some other embodiments, the dummy pole lugs 121 of the anode lug unit and the cathode lug unit extend into different avoidance grooves 210 respectively.

[0058] Combination Figure 2 , Figure 3 and Figure 7 It should be noted that bare cells 100 are arranged on both sides of the partition 200, and avoidance grooves 210 are arranged on both sides of the partition 200; one of the bare cells 100 is the first bare cell 100a, and the other bare cell 100 is the second bare cell 100b; the avoidance groove 210 arranged on the side of the partition 200 close to the first bare cell 100a is the first avoidance groove, and the avoidance groove 210 arranged on the side of the partition 200 close to the second bare cell 100b is the second avoidance groove.

[0059] The dummy pole lug 121 of the pole lug unit 120 on the first bare battery cell 100a is bent and extends into the first avoidance groove, and the pole lug 122 on the first bare battery cell 100a is joined with the part of the dummy pole lug 121 on the first bare battery cell 100a extending into the first avoidance groove, and extends out of the first avoidance groove; the dummy pole lug 121 of the pole lug unit 120 on the second bare battery cell 100b is bent and extends into the second avoidance groove, and the pole lug 122 on the second bare battery cell 100b is joined with the part of the dummy pole lug 121 on the second bare battery cell 100b extending into the second avoidance groove, and extends out of the second avoidance groove.

[0060] Combination Figure 3 and Figure 4In the battery cell assembly of the present invention, by setting an avoidance groove 210 on the side of the partition 200 close to the bare battery cell body 110, the fake pole ear 121 can be bent and extended into the avoidance groove 210, so as to change the extension direction of the fake pole ear 121, and the fake pole ear 121 extending into the avoidance groove 210 is connected with the pole ear 122. Compared with the straight-out fake pole ear 121, the space occupied by the pole ear unit 120 in the longitudinal direction of the battery cell can be reduced, which is beneficial to improve the utilization rate of the longitudinal space of the battery cell and improve the energy density.

[0061] Compare Figure 4 and Figure 6 It should be noted that, for the straight-out type fake pole lug 121, since it does not bend and extends directly in the longitudinal direction, after the pole lug 122 is connected to the fake pole lug 121, the entire pole lug unit 120 will occupy a larger space in the longitudinal direction of the battery cell; and in the present application, the fake pole lug 121 is bent and extended into the avoidance groove 210, so that the extension direction of the fake pole lug 121 can be at a certain angle to the longitudinal direction, thereby reducing the space occupied by the fake pole lug 121 in the longitudinal direction of the battery cell. In this way, the pole lug unit 120 formed after the pole lug 122 and the fake pole lug 121 are joined will occupy a smaller space in the longitudinal direction of the battery cell.

[0062] Combination Figure 3 and Figure 4 It should be further explained that, in the present application, the purpose of setting the avoidance groove 210 on the side of the partition 200 close to the bare battery body 110 is to ensure that the length of the bent part of the fake pole ear 121 can meet the welding requirements of the pole ear 122 and the fake pole ear 121.

[0063] It is understandable that when the pole ear 122 and the fake pole ear 121 are connected by welding, since the welding width has a lower limit (if the welding width is lower than the lower limit, the pole ear 122 and the fake pole ear 121 cannot be welded, or the pole ear 122 and the fake pole ear 121 cannot be stably welded), and since the bare battery cell 100 of the inner series battery is usually set to be relatively thin, after the fake pole ear 121 is bent, in order to ensure that the length of the fake pole ear 121 after bending meets the welding requirements, the bent portion of the fake pole ear 121 will exceed the bare battery body 110. Therefore, the present application sets an avoidance groove 210 on the partition 200, and the space in the avoidance groove 210 can be used to meet the length requirement of the fake pole ear 121 after bending.

[0064] Combination Figure 3 and Figure 4Further, a side of the bare cell body 110 close to the partition 200 is defined as a reference plane, the fake pole ear 121 extends from the bare cell body 110 toward the avoidance groove 210 and exceeds the reference plane, and the length H of the part of the fake pole ear 121 exceeding the reference plane in a preset direction is less than the thickness D of the bare cell body 110; wherein the preset direction is perpendicular to the reference plane.

[0065] It should be noted that bare battery cells 100 must be arranged on both sides of the partition 200, and the performance of each bare battery cell 100 must be consistent, and the thickness of each bare battery cell 100 must be basically the same. Therefore, the length H of the portion of the fake pole ear 121 that exceeds the reference plane in a preset direction is ensured to be less than the thickness D of the bare battery cell 100, which can prevent the fake pole ear 121 from exceeding another bare battery cell 100.

[0066] Furthermore, the length H of the portion of the dummy pole tab 121 that exceeds the reference plane in the preset direction is less than or equal to the thickness D of the avoidance groove 210 , so that the avoidance groove 210 can accommodate the bent dummy pole tab 121 and the pole tab 122 .

[0067] Furthermore, a protrusion 220 opposite to the notch of the avoidance groove 210 is provided on the side of the partition 200 away from the bare battery cell 100, and the avoidance groove 210 extends into the protrusion 220. The setting of the protrusion 220 can increase the depth of the avoidance groove 210, thereby ensuring that the depth of the avoidance groove 210 meets the requirements, thereby ensuring that the length of the false pole ear 121 after bending meets the requirements.

[0068] It can be understood that by providing a protrusion 220 on the side of the partition 200 away from the bare battery cell 100, the depth of the avoidance groove 210 can be deepened to exceed the thickness of the partition 200, so that the bent fake pole ear 121 has a larger storage space to meet the storage requirements of the fake pole ear 121.

[0069] The depth of the avoidance groove 210 is less than or equal to the thickness of the bare cell body 110 .

[0070] It can be understood that when ensuring that the length H of the portion of the fake pole ear 121 that exceeds the reference plane in the preset direction is less than the thickness D of the bare battery cell body 110, it is only necessary to ensure that the depth of the avoidance groove 210 is less than or equal to the thickness of the bare battery cell body 110, and there is no need to set an overly deep avoidance groove 210.

[0071] In addition, by setting a deeper avoidance groove 210 on the side of the partition 200 close to the bare battery body 110, the overlapping area between the fake pole lug 121 and the pole lug 122 can be further made larger, so that the welding area between the fake pole lug 121 and the pole lug 122 is larger, thereby making the welding tension between the fake pole lug 121 and the pole lug 122 larger, which can reduce the risk of breakage of the pole lug unit 120.

[0072] In some embodiments, the partition 200 includes an aluminum layer and protective layers respectively disposed on both sides of the aluminum layer, wherein the material of the protective layers is PP (polypropylene).

[0073] Furthermore, the thickness of the aluminum layer is less than or equal to 30 μm and greater than or equal to 50 μm.

[0074] category means Example 1 Punch a 1.5mm deep avoidance groove on a 20μm thick aluminum partition Example 2 Punch a 1.5mm deep avoidance groove on a 30μm thick aluminum partition Example 3 Punch a 1.5mm deep avoidance groove on a 40μm thick aluminum partition Example 4 Punch a 1.5mm deep avoidance groove on a 50μm thick aluminum partition

[0075] category result Example 1 Broken partition Example 2 The partition is normal, and the depth of the avoidance groove is 1.5mm Example 3 The partition is normal, and the depth of the avoidance groove is 1.5mm Example 4 The partition is normal, and the depth of the avoidance groove is 1.0mm

[0076] According to the experimental results, when the thickness of the aluminum layer of the partition 200 is 20μm, it cannot withstand the punching; when the thickness of the aluminum layer of the partition 200 is 30μm-40μm, the avoidance groove 210 that meets the requirements can be punched out; when the thickness of the aluminum layer of the partition 200 is 50μm, the depth of the avoidance groove 210 cannot meet the requirements due to the rebound of the aluminum layer. Therefore, the thickness of the aluminum layer of the partition 200 needs to be less than or equal to 30μm and greater than or equal to 50μm.

[0077] In some embodiments, the tab 122 is welded to the fake tab 121; wherein the width of the avoidance groove 210 is T, the thickness of the weld mark formed by welding the tab 122 to the fake tab 121 is B, and the thickness of the tab 122 is C; wherein,

[0078]

[0079] like Figure 8 , Fig. 9 As shown, the present application also provides a single battery cell, including an outer film 300 and the battery cell assembly as described above.

[0080] The outer membrane 300 is formed with an inner cavity 310 .

[0081] Specifically, the outer film 300 includes a first aluminum-plastic film 300 a and a second aluminum-plastic film 300 b , and the first aluminum-plastic film 300 a and the second aluminum-plastic film 300 b are covered together to form an inner cavity 310 .

[0082] The cell assembly is arranged inside the inner cavity 310 , the bare cell body 110 is located inside the inner cavity 310 and is spaced apart from one of the side walls of the inner cavity 310 to form a gap (whose width is S), and the avoidance groove 210 is located in the gap.

[0083] In the single cell of the utility model, by setting an avoidance groove 210 on the side of the partition 200 close to the bare cell body 110, the dummy pole ear 121 can be bent and extended into the avoidance groove 210, so as to change the extension direction of the dummy pole ear 121, and the dummy pole ear 121 extended into the avoidance groove 210 is connected with the pole ear 122. Compared with the straight-out dummy pole ear 121, the space occupied by the pole ear unit 120 in the longitudinal direction of the cell can be reduced, thereby reducing the width S of the gap, which is beneficial to improving the utilization rate of the longitudinal space of the cell and improving the energy density.

[0084] The present application also provides an internal series battery, including the battery cell assembly as described above, or the single battery cell as described above.

[0085] In the internal series battery of the present invention, the battery cell assembly is provided with an avoidance groove 210 on one side of the partition 200 close to the bare battery cell body 110, so that the dummy pole ear 121 can be bent and extended into the avoidance groove 210, thereby changing the extension direction of the dummy pole ear 121, and the dummy pole ear 121 extending into the avoidance groove 210 is connected with the pole ear 122. Compared with the straight-out dummy pole ear 121, the space occupied by the pole ear unit 120 in the longitudinal direction of the battery cell can be reduced, which is beneficial to improving the utilization rate of the longitudinal space of the battery cell and improving the energy density.

[0086] In the description of this specification, 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.

[0087] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery cell assembly, characterized in that: The battery cell assembly comprises a bare battery cell and a separator; The bare cell comprises a bare cell body and a tab unit connected to the side of the bare cell body, the bare cell body and the partition are stacked, and a side of the partition close to the bare cell body is provided with an avoidance groove staggered with the bare cell body; Among them, the pole ear unit includes a dummy pole ear and a pole ear, one end of the dummy pole ear is connected to the side of the bare battery cell body, the dummy pole ear is bent and extends into the inside of the avoidance groove, and the pole ear is joined to the part of the dummy pole ear extending into the avoidance groove and extends outside the avoidance groove.

2. The battery cell assembly according to claim 1, characterized in that: A side of the bare cell body close to the partition is defined as a reference plane, the dummy tab extends from the bare cell body toward the avoidance groove and exceeds the reference plane, the length of the portion of the dummy tab exceeding the reference plane in a preset direction is less than or equal to the depth of the avoidance groove, and the depth of the avoidance groove is less than or equal to the thickness of the bare cell; Wherein, the preset direction is perpendicular to the reference plane.

3. The battery core assembly according to claim 1, characterized in that: A protrusion opposite to the notch of the avoidance groove is provided on one side of the partition away from the bare battery cell, and the avoidance groove extends into the protrusion.

4. The battery core assembly according to claim 1, characterized in that: The partition includes an aluminum layer and protective layers respectively arranged on both sides of the aluminum layer, and the thickness of the aluminum layer is less than or equal to 30 μm and greater than or equal to 50 μm.

5. The battery core assembly according to claim 1, characterized in that: The pole tab is welded to the dummy pole tab; Wherein, the width of the avoidance groove is T, the thickness of the weld mark formed by welding the pole tab and the fake pole tab is B, and the thickness of the pole tab is C; in, 6. The battery core assembly according to claim 1, characterized in that: The pole lug is also engaged with a dummy pole lug that does not extend into the avoidance groove.

7. The battery cell assembly according to claim 1, characterized in that: The position of the junction between the false pole tab and the bare battery cell body is opposite to the position of the avoidance groove.

8. The battery core assembly according to claim 1, characterized in that: The bare cells are arranged on both sides of the partition, and the avoidance grooves are arranged on both sides of the partition; One of the bare cells is a first bare cell, and the other bare cell is a second bare cell; the avoidance groove provided on the side of the partition close to the first bare cell is a first avoidance groove, and the avoidance groove provided on the side of the partition close to the second bare cell is a second avoidance groove; The dummy tab on the first bare cell is bent and extends into the first avoidance groove, and the tab on the first bare cell is joined to the portion of the dummy tab on the first bare cell extending into the first avoidance groove and extends out of the first avoidance groove; The dummy pole tab on the second bare battery cell is bent and extends into the second avoidance groove, and the pole tab on the second bare battery cell is joined to the portion of the dummy pole tab on the second bare battery cell extending into the second avoidance groove and extends out of the second avoidance groove.

9. A single cell, characterized in that: include: The battery cell assembly according to any one of claims 1 to 8; an outer membrane, the outer membrane forming an inner cavity; Wherein, the battery cell assembly is arranged inside the inner cavity, the bare battery cell body is located inside the inner cavity and is spaced apart from one of the side walls of the inner cavity to form a gap, and the avoidance groove is located in the gap.

10. An internal series battery, characterized in that: A battery cell assembly comprising any one of claims 1 to 8; or a single battery cell as claimed in claim 9.

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