Battery cell and battery

Abstract

The utility model discloses a battery cell and discloses a battery with the battery cell, the battery cell comprises a first battery cell single body, the first battery cell single body comprises a first pole piece, a first diaphragm, a second pole piece and a second diaphragm which are stacked in sequence, the first pole piece comprises a first composite current collector and a first active material layer, and the second pole piece comprises a second composite current collector and a second active material layer. The first composite current collector comprises a first conductive layer, a first insulating layer and a first conductive layer which are sequentially stacked, the first active material layer is arranged on the corresponding first conductive layer, and the second pole piece comprises a second composite current collector and a second active material layer; the second composite current collector comprises a second conducting layer, a second insulating layer and a second conducting layer which are stacked in sequence, the second active material layer is arranged on the corresponding second conducting layer, and the two opposite sides of the first diaphragm are connected with the two opposite sides of the first insulating layer respectively; and two opposite sides of the second diaphragm are respectively connected with two opposite sides of the second insulating layer, so that the structural stability of the battery cell can be improved.

Description

Technical Field

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

[0002] For the existing wound or laminated battery cells, the tightness of the battery cell will directly affect the performance of the battery cell. An over-tight battery cell may cause the pole piece to break, thereby increasing the safety risk of the battery; if the tightness is too small, it is easy for the positive pole piece, the separator and the negative pole piece to loosen, resulting in poor structural stability of the battery cell. Summary of the Utility Model

[0003] The utility model aims to at least solve one of the technical problems existing in the prior art. For this purpose, the utility model provides a battery cell, which can improve the structural stability of the battery cell.

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

[0005] The battery cell according to the first aspect embodiment of the utility model includes:

[0006] A first battery cell monomer, including a first pole piece, a first separator, a second pole piece and a second separator which are sequentially stacked, and the first battery cell monomer is wound to form the battery cell;

[0007] The first pole piece includes a first composite current collector and a first active material layer, the first composite current collector includes a first conductive layer, a first insulating layer and a first conductive layer which are sequentially stacked, and the first active material layer is arranged on the corresponding first conductive layer;

[0008] The second pole piece includes a second composite current collector and a second active material layer, the second composite current collector includes a second conductive layer, a second insulating layer and a second conductive layer which are sequentially stacked, and the second active material layer is arranged on the corresponding second conductive layer;

[0009] The opposite sides of the first separator are respectively connected to the opposite sides of the first insulating layer, the opposite sides of the second separator are respectively connected to the opposite sides of the second insulating layer, and both the first separator and the second separator are configured to isolate the corresponding first conductive layer and the second conductive layer.

[0010] The battery cell according to the first aspect embodiment of the utility model has at least the following beneficial effects:

[0011] The first separator and the second separator of this embodiment are respectively connected to the first insulating layer and the second insulating layer, which can reduce the relative movement between the first separator and the first electrode tab, and reduce the relative movement between the second separator and the second electrode tab, improving the structural stability of the battery cell, thereby enhancing the electrochemical performance and the usage safety of the battery cell. On the other hand, the first separator and the second separator of this embodiment are respectively connected to the first insulating layer and the second insulating layer, which can also avoid the risk of short circuit between the first conductive layer and the second conductive layer caused by the shrinkage and deformation of the first separator and the second separator, improving the usage safety of the battery.

[0012] According to some embodiments of the present invention, along the width direction of the first battery cell unit, the opposite sides of the first separator are respectively connected to the opposite sides of the first insulating layer, and the opposite sides of the second separator are respectively connected to the opposite sides of the second insulating layer.

[0013] According to some embodiments of the present invention, the opposite sides of the first separator are respectively connected to the opposite sides of the first insulating layer by melting;

[0014] The opposite sides of the second separator are respectively connected to the opposite sides of the second insulating layer by melting.

[0015] According to some embodiments of the present invention, the first separator includes a first connecting portion, a first main body portion, and a second connecting portion. The first connecting portion and the second connecting portion are disposed opposite to each other. The first connecting portion is connected to the second connecting portion through the first main body portion. The first main body portion is located between the first conductive layer and the corresponding second conductive layer. The first connecting portion is connected to one side of the first insulating layer, and the second connecting portion is connected to the opposite side of the first insulating layer.

[0016] According to some embodiments of the present invention, the widths of the first connecting portion and the second connecting portion are equal.

[0017] According to some embodiments of the present invention, the width of the first connecting portion is a, the thickness of the first conductive layer is b, the thickness of the first insulating layer is c, and the thickness of the first active material layer is d. a, b, c, and d satisfy: b + d < a ≤ b + c + d.

[0018] According to some embodiments of the present invention, one side of the first connecting portion facing the second connecting portion is attached to one side of the corresponding first conductive layer, and one side of the second connecting portion facing the first connecting portion is attached to the opposite side of the corresponding first conductive layer.

[0019] According to some embodiments of the present utility model, the first composite current collector further includes a first connection layer, the first connection layer is disposed on the first insulating layer, and the two first conductive layers are electrically connected through the first connection layer;

[0020] And / or, the second composite current collector further includes a second connection layer, the second connection layer is disposed on the second insulating layer, and the two second conductive layers are electrically connected through the second connection layer.

[0021] The battery cell according to the second aspect embodiment of the present utility model includes:

[0022] A plurality of second battery cell monomers, the second battery cell monomers include a third electrode sheet, a third separator, a fourth electrode sheet, and a fourth separator which are sequentially stacked, and the plurality of second battery cell monomers are sequentially stacked to form the battery cell;

[0023] The third electrode sheet includes a third composite current collector and a third active material layer, the third composite current collector includes a third conductive layer, a third insulating layer, and a third conductive layer which are sequentially stacked, and the third active material layer is disposed on the corresponding third conductive layer;

[0024] The fourth electrode sheet includes a fourth composite current collector and a fourth active material layer, the fourth composite current collector includes a fourth conductive layer, a fourth insulating layer, and a fourth conductive layer which are sequentially stacked, and the fourth active material layer is disposed on the corresponding fourth conductive layer;

[0025] Opposite sides of the third separator are respectively connected to opposite sides of the third insulating layer, opposite sides of the fourth separator are respectively connected to opposite sides of the fourth insulating layer, and both the third separator and the fourth separator are configured to isolate the corresponding third conductive layer and the fourth conductive layer.

[0026] According to some embodiments of the present utility model, along the width direction of the second battery cell monomer, opposite sides of the third separator are respectively connected to opposite sides of the third insulating layer, and opposite sides of the fourth separator are respectively connected to opposite sides of the fourth insulating layer.

[0027] According to some embodiments of the present utility model, opposite sides of the third separator are respectively melt-connected to opposite sides of the third insulating layer, and opposite sides of the fourth separator are respectively melt-connected to opposite sides of the fourth insulating layer.

[0028] The battery according to the third aspect embodiment of the present utility model includes: a housing and the battery cell, and the battery cell is accommodated in the housing.

[0029] Additional aspects and advantages of the present utility model will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present utility model. Description of the Drawings

[0030] The above and / or additional aspects and advantages of the present utility model will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0031] Figure 1 is a schematic structural diagram of a battery cell according to an embodiment of the first aspect of the present utility model;

[0032] Figure 2 is a schematic structural diagram of another embodiment of a battery cell according to an embodiment of the first aspect of the present utility model;

[0033] Figure 3 is a schematic structural diagram of a battery cell according to an embodiment of the second aspect of the present utility model.

[0034] Reference numerals:

[0035] First electrode plate 100, first composite current collector 110, first insulating layer 111, first conductive layer 112, first connection layer 113, first active material layer 120;

[0036] First separator 200, first connection portion 210, first main body portion 220, second connection portion 230;

[0037] Second electrode plate 300, second composite current collector 310, second insulating layer 311, second conductive layer 312, second connection layer 313, second active material layer 320;

[0038] Second separator 400, third connection portion 410, second main body portion 420, fourth connection portion 430;

[0039] Third electrode plate 500, third composite current collector 510, third insulating layer 511, third conductive layer 512, third active material layer 520;

[0040] Third separator 600;

[0041] Fourth electrode plate 700, fourth composite current collector 710, fourth insulating layer 711, fourth conductive layer 712, fourth active material layer 720;

[0042] Fourth separator 800. Detailed Embodiments

[0043] Embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation to the present utility model.

[0044] In the description of the present utility model, it should be understood that with respect to the orientation description, such as the upper, lower, front, rear, left, right, etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings. It is 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 should not be construed as a limitation to the present utility model.

[0045] In the description of the present utility model, the meaning of "several" is one or more, the meaning of "multiple" is two or more, "greater than", "less than", "exceeding", etc. are understood not to include the present number, and "above", "below", "within", etc. are understood to include the present number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0046] In the description of the present utility model, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present utility model in combination with the specific content of the technical solution.

[0047] As described above, in the related art, for the existing wound or laminated battery cells, the tightness of the battery cells will directly affect the performance of the battery cells. An overly tight battery cell may cause the pole piece to break, thereby increasing the safety risk of the battery; if the tightness is too small, the positive pole piece, the separator and the negative pole piece are likely to become loose, and the structural stability is poor. Based on this, the present utility model provides a battery cell, in which the separator is connected to the insulating layer of the composite current collector, which can reduce the looseness between the positive pole piece, the separator and the negative pole piece, so as to improve the structural stability of the battery cell, thereby improving the electrochemical performance and safety of the battery cell.

[0048] The current collector is the carrier of the positive and negative active materials in the lithium / sodium ion battery. The current collector is used for the collection and conduction of positive and negative electrons to collect the current generated by the active material and output a larger current. The composite current collector has a sandwich structure, with a functional insulating polymer polymer layer on the inner layer and conductive layers deposited on the upper and lower surfaces by methods such as deposition / sputtering. The composite current collector has the characteristics of high safety and improved energy density.

[0049] Embodiment 1

[0050] Refer toFigure 1 When the battery cell is configured as a wound battery cell, the first electrode sheet 100, the first separator 200, the second electrode sheet 300, and the second separator 400 are sequentially stacked by a lamination device to form a first battery cell monomer. Then, the first battery cell monomer is wound by a winding device to form the battery cell of this embodiment.

[0051] Among them, the first electrode sheet 100 includes a first composite current collector 110 and a first active material layer 120. The first composite current collector 110 includes a first conductive layer 112, a first insulating layer 111, and a first conductive layer 112 that are sequentially stacked. The first insulating layer 111 is sandwiched between the adjacent first conductive layers 112 on both sides. The second electrode sheet 300 includes a second composite current collector 310 and a second active material layer 320. The second composite current collector 310 includes a second conductive layer 312, a second insulating layer 311, and a second conductive layer 312 that are sequentially stacked. The second active material layer 320 is disposed on the corresponding second conductive layer 312. The second insulating layer 311 is sandwiched between the adjacent second conductive layers 312 on both sides. Both the first separator 200 and the second separator 400 are configured to isolate the corresponding first conductive layer 112 and second conductive layer 312. Since the opposite sides of the first separator 200 are respectively connected to the opposite sides of the first insulating layer 111, the relative movement between the first separator 200 and the first electrode sheet 100 can be reduced. Similarly, the opposite sides of the second separator 400 are respectively connected to the opposite sides of the second insulating layer 311, and the relative movement between the second separator 400 and the second electrode sheet 300 can be reduced. In this way, the structural stability of the battery cell can be improved, thereby improving the electrochemical performance and use safety of the battery cell.

[0052] It should be noted that the first separator 200 and the second separator 400 are respectively connected to the first insulating layer 111 and the second insulating layer 311, which can also avoid the risk of short circuit between the first conductive layer 112 and the second conductive layer 312 caused by the shrinkage and deformation of the first separator 200 and the second separator 400, and can improve the use safety of the battery.

[0053] It should be pointed out that one of the first electrode sheet 100 and the second electrode sheet 300 is configured as a positive electrode sheet, and the other is configured as a negative electrode sheet. The first separator 200 and the second separator 400 allow the ions transmitted between the first active material layer 120 and the second active material layer 320 to pass through, which will not be elaborated here.

[0054] It can be understood that there are two layers of the first active material layer 120 corresponding to the configuration. The first active material layer 120 is disposed on the surface of the first conductive layer 112 facing away from the first insulating layer 111. Similarly, the second active material layer 320 is disposed on the surface of the second conductive layer 312 facing away from the second insulating layer 311, which can increase the first active material layer 120 and the second active material layer 320, thereby improving the energy density of the battery.

[0055] In some embodiments of the present utility model, along the width direction of the first battery cell unit, the opposite sides of the first separator 200 are respectively connected to the opposite sides of the first insulating layer 111, which can increase the contact area between the first separator 200 and the first insulating layer 111, so as to improve the connection stability between the first separator 200 and the first insulating layer 111, thereby improving the connection stability between the first separator 200 and the first insulating layer 111.

[0056] Specifically, along the width direction of the first battery cell unit, one side of the first separator 200 is connected to one side of the first insulating layer 111, and the opposite side of the first separator 200 is connected to the opposite side of the first insulating layer 111, which can increase the contact area between the first separator 200 and the first insulating layer 111, so as to improve the connection stability between the first separator 200 and the first insulating layer 111, thereby improving the connection stability between the first separator 200 and the first insulating layer 111.

[0057] Similarly, along the width direction of the first battery cell unit, the opposite sides of the second separator 400 are respectively connected to the opposite sides of the second insulating layer 311, that is, one side of the second separator 400 is connected to one side of the second insulating layer 311, and the opposite side of the second separator 400 is connected to the opposite side of the second insulating layer 311, which can increase the contact area between the second separator 400 and the second insulating layer 311, so as to improve the connection stability between the second separator 400 and the second insulating layer 311, thereby improving the connection stability between the second separator 400 and the second insulating layer 311.

[0058] Of course, in some specific embodiments, it may also be that along the length direction of the first battery cell unit, the opposite sides of the first separator 200 are respectively connected to the opposite sides of the first insulating layer 111, and the opposite sides of the second separator 400 are respectively connected to the opposite sides of the second insulating layer 311, which can also effectively fix the first separator 200 and the second separator 400, thereby reducing the looseness between the first electrode sheet 100, the first separator 200, the second electrode sheet 300 and the second separator 400, and improving the structural stability of the battery cell, which will not be elaborated here.

[0059] It should be noted that the first electrode sheet 100, the first separator 200, the second electrode sheet 300 and the second separator 400 are all in a strip-shaped structure, and the first battery cell unit is in a strip-shaped structure before being wound. For example Figure 1 as shown, the width direction of the first battery cell unit is Figure 1 the left-right direction in Figure 1 the up-down direction in Figure 1 the direction perpendicular to the paper surface in

[0060] In some embodiments of the present utility model, after the first battery cell unit is wound by a winding device, the two opposite sides of the first separator 200 are respectively melt-connected to the two opposite sides of the first insulating layer 111, and the two opposite sides of the second separator 400 are respectively melt-connected to the two opposite sides of the second insulating layer 311 through a heat melting device, which can facilitate the connection and fixation of the first separator 200 and the second separator 400.

[0061] Specifically, during heat melting, the heat melting device can simultaneously heat-melt the same side of the first separator 200 and the second separator 400. After that, the heat melting device simultaneously heat-melts the other side of the first separator 200 and the second separator 400. The operation is simple, convenient and fast, which can facilitate the connection and fixation of the first separator 200 and the second separator 400.

[0062] Of course, in some specific embodiments, the heat melting device can also simultaneously heat-melt the two opposite sides of the first separator 200 and the second separator 400, so that the two opposite sides of the first separator 200 are respectively melt-connected to the two opposite sides of the first insulating layer 111, and the two opposite sides of the second separator 400 are respectively melt-connected to the two opposite sides of the second insulating layer 311, which will not be elaborated here.

[0063] In some embodiments of the present utility model, the first separator 200 includes a first connecting portion 210, a first main body portion 220 and a second connecting portion 230. The first connecting portion 210 and the second connecting portion 230 are oppositely arranged. The first connecting portion 210 is connected to the second connecting portion 230 through the first main body portion 220. The first main body portion 220 is located between the first conductive layer 112 and the corresponding second conductive layer 312. The first connecting portion 210 is connected to one side of the first insulating layer 111, and the second connecting portion 230 is connected to the opposite other side of the first insulating layer 111, which can facilitate the connection of the first separator 200.

[0064] Specifically, the first separator 200 has an overall U-shaped structure. Along the width direction of the first battery cell unit, the first connecting portion 210 and the second connecting portion 230 are oppositely arranged. One side of the first main body portion 220 is connected to the first connecting portion 210, and the opposite other side of the first main body portion 220 is connected to the second connecting portion 230. The first separator 200 is a flat structure before being heat-melted, and the first connecting portion 210 and the second connecting portion 230 are generated after the first separator 200 is heat-melted, which can facilitate the connection of the first separator 200.

[0065] It should be noted that along the width direction of the first battery cell unit, the first connecting portion 210 is attached to one side of the first conductive layer 112, so that there is no gap between the first connecting portion 210 and one side of the first electrode tab 100. The second connecting portion 230 is attached to the opposite side of the first conductive layer 112, so that there is no gap between the second connecting portion 230 and the opposite side of the second electrode tab 300. That is, the width of the first main body portion 220 matches the width of the first insulating layer 111, so that the first separator 200 is in a tensioned state, which can reduce the looseness of the first separator 200 relative to the first electrode tab 100, thereby improving the structural stability of the battery cell.

[0066] In some embodiments of the present invention, the second separator 400 includes a third connecting portion 410, a second main body portion 420, and a fourth connecting portion 430. The third connecting portion 410 and the fourth connecting portion 430 are oppositely arranged. The third connecting portion 410 is connected to the fourth connecting portion 430 through the second main body portion 420. The second main body portion 420 is located between the first conductive layer 112 and the corresponding second conductive layer 312. The third connecting portion 410 is connected to one side of the first insulating layer 111, and the fourth connecting portion 430 is connected to the opposite side of the first insulating layer 111, which can facilitate the connection of the second separator 400.

[0067] In some embodiments of the present invention, the widths of the first connecting portion 210 and the second connecting portion 230 are equal, so that the tension between the first connecting portion 210 and the first main body portion 220 is equal to the tension between the second connecting portion 230 and the first main body portion 220, and the forces on both sides of the first main body portion 220 in the width direction are equal.

[0068] It should be noted that the width direction of the first connecting portion 210 and the width direction of the second connecting portion 230 refer to Figure 1 the up-and-down direction in

[0069] In some embodiments of the present invention, the width of the first connecting portion 210 is a, the thickness of the first conductive layer 112 is b, the thickness of the first insulating layer 111 is c, and the thickness of the first active material layer 120 is d. a, b, c, and d satisfy: b + d < a ≤ b + c + d, which ensures that the first connecting portion 210 can be connected to the first insulating layer 111 and can improve the use safety of the battery cell.

[0070] It should be pointed out that when a=b+c / 2+d, the side of the first connecting part 210 away from the first main body part 220 is located in the middle of the first insulating layer 111; when a=b+c+d, the side of the first connecting part 210 away from the first main body part 220 is flush with the surface of the first insulating layer 111 away from the first main body part 220, which can ensure the contact area between the first connecting part 210 and the first insulating layer 111, so that the first connecting part 210 can be stably connected to the first insulating layer 111.

[0071] In some embodiments of the present invention, the first composite current collector 110 also includes a first connecting layer 113, which is disposed on the first insulating layer 111, and the two first conductive layers 112 are electrically connected through the first connecting layer 113. The second composite current collector 310 also includes a second connecting layer 313, which is disposed on the second insulating layer 311, and the two second conductive layers 312 are electrically connected through the second connecting layer 313, which can improve the energy density and electrochemical capacity of the battery cell.

[0072] Specifically, the first connection layer 113 may be configured with at least one layer, and the first connection layer 113 is in a columnar structure. When the first connection layer 113 is configured with one layer, the first connection layer 113 may be extended in the up-down direction, or may be extended in a direction inclined relative to the up-down direction. The upper end of the first connection layer 113 is connected to the first conductive layer 112 located above, and the lower end of the first connection layer 113 is connected to the first conductive layer 112 located below.

[0073] When the first connection layer 113 is configured with multiple layers, the multiple first connection layers 113 can be arranged side by side with intervals, or can be connected end to end. Specifically, for example Figure 2 As shown, when the first connection layer 113 is configured with three layers, the three first connection layers 113 may be in an N-shaped structure.

[0074] Similarly, the second connection layer 313 may be configured with at least one layer, and the second connection layer 313 is a columnar structure. When the second connection layer 313 is configured with one layer, the second connection layer 313 may be extended in the up-down direction, or may be extended in a direction inclined relative to the up-down direction. The upper end of the second connection layer 313 is connected to the second conductive layer 312 located above, and the lower end of the second connection layer 313 is connected to the second conductive layer 312 located below.

[0075] When the second connection layer 313 is configured with multiple layers, the multiple layers of the second connection layer 313 can be arranged side by side or connected end to end. Specifically, for example Figure 2 As shown, when the second connection layer 313 is configured with three layers, the three second connection layers 313 may be in an N-shaped structure.

[0076] Example 2

[0077] Reference Figure 3 When the battery cell is configured as a stacked battery cell, the first electrode sheet 100, the first separator 200, the second electrode sheet 300, and the second separator 400 are sequentially stacked by a stacking device to form a second battery cell unit, and then a plurality of second battery cell units are sequentially stacked to form the battery cell of this embodiment.

[0078] Among them, the third electrode sheet 500 includes a third composite current collector 510 and a third active material layer 520. The third composite current collector 510 includes a third conductive layer 512, a third insulating layer 511, and a third conductive layer 512 that are sequentially stacked. The third insulating layer 511 is sandwiched between the adjacent third conductive layers 512 on both sides. The fourth electrode sheet 700 includes a fourth composite current collector 710 and a fourth active material layer 720. The fourth composite current collector 710 includes a fourth conductive layer 712, a fourth insulating layer 711, and a fourth conductive layer 712 that are sequentially stacked. The fourth active material layer 720 is disposed on the corresponding fourth conductive layer 712. The fourth insulating layer 711 is sandwiched between the adjacent fourth conductive layers 712 on both sides. Both the third separator 600 and the fourth separator 800 are configured to isolate the corresponding third conductive layer 512 and fourth conductive layer 712. Since the opposite sides of the third separator 600 are respectively connected to the opposite sides of the third insulating layer 511, the relative movement between the third separator 600 and the third electrode sheet 500 can be reduced. Similarly, the opposite sides of the fourth separator 800 are respectively connected to the opposite sides of the fourth insulating layer 711, and the relative movement between the fourth separator 800 and the fourth electrode sheet 700 can be reduced. In this way, the structural stability of the battery cell can be improved, thereby improving the electrochemical performance and use safety of the battery cell.

[0079] It should be noted that one of the third electrode sheet 500 and the fourth electrode sheet 700 is configured as a positive electrode sheet, and the other is configured as a negative electrode sheet. The third separator 600 and the fourth separator 800 allow ions transmitted between the third active material layer 520 and the fourth active material layer 720 to pass through, which will not be elaborated here.

[0080] It can be understood that two layers of the third active material layer 520 are correspondingly configured. The third active material layer 520 is disposed on the surface of the third conductive layer 512 facing away from the third insulating layer 511. Similarly, the fourth active material layer 720 is disposed on the surface of the fourth conductive layer 712 facing away from the fourth insulating layer 711, which can increase the third active material layer 520 and the fourth active material layer 720, thereby improving the energy density of the battery.

[0081] In some embodiments of the present utility model, along the width direction of the second battery cell unit, the opposite sides of the third separator 600 are respectively connected to the opposite sides of the third insulating layer 511, and the opposite sides of the fourth separator 800 are respectively connected to the opposite sides of the fourth insulating layer 711, which can increase the contact area between the third separator 600 and the third insulating layer 511, so as to improve the connection stability between the third separator 600 and the third insulating layer 511, thereby improving the connection stability between the third separator 600 and the third insulating layer 511.

[0082] Specifically, along the width direction of the third battery cell unit, one side of the third separator 600 is connected to one side of the third insulating layer 511, and the opposite side of the third separator 600 is connected to the opposite side of the third insulating layer 511, which can increase the contact area between the third separator 600 and the third insulating layer 511, so as to improve the connection stability between the third separator 600 and the third insulating layer 511, thereby improving the connection stability between the third separator 600 and the third insulating layer 511.

[0083] Similarly, along the width direction of the third battery cell unit, the opposite sides of the fourth separator 800 are respectively connected to the opposite sides of the fourth insulating layer 711, that is, one side of the fourth separator 800 is connected to one side of the fourth insulating layer 711, and the opposite side of the fourth separator 800 is connected to the opposite side of the fourth insulating layer 711, which can increase the contact area between the fourth separator 800 and the fourth insulating layer 711, so as to improve the connection stability between the fourth separator 800 and the fourth insulating layer 711, thereby improving the connection stability between the fourth separator 800 and the fourth insulating layer 711.

[0084] Of course, in some specific embodiments, it may also be that along the length direction of the third battery cell unit, the opposite sides of the third separator 600 are respectively connected to the opposite sides of the third insulating layer 511, and the opposite sides of the fourth separator 800 are respectively connected to the opposite sides of the fourth insulating layer 711, which can also effectively fix the third separator 600 and the fourth separator 800, thereby reducing the looseness between the third electrode sheet 500, the third separator 600, the fourth electrode sheet 700 and the fourth separator 800, and improving the structural stability of the battery cell, which will not be elaborated here.

[0085] In some embodiments of the present utility model, after multiple second battery cell units are stacked by a stacking device, through a hot melting device, the opposite sides of the third separator 600 are respectively melt-connected to the opposite sides of the third insulating layer 511, and the opposite sides of the fourth separator 800 are respectively melt-connected to the opposite sides of the fourth insulating layer 711, which can facilitate the connection and fixation of the third separator 600 and the fourth separator 800.

[0086] Specifically, during hot melting, the hot melting device can simultaneously hot melt the same side of the third diaphragm 600 and the fourth diaphragm 800. After that, the hot melting device simultaneously hot melts the other side of the third diaphragm 600 and the fourth diaphragm 800. The operation is simple, convenient and fast, which can facilitate the connection and fixation of the third diaphragm 600 and the fourth diaphragm 800.

[0087] Of course, in some specific embodiments, the hot melting device can also simultaneously hot melt the opposite sides of the third diaphragm 600 and the fourth diaphragm 800, so that the opposite sides of the third diaphragm 600 are respectively melt-connected to the opposite sides of the third insulating layer 511, and the opposite sides of the fourth diaphragm 800 are respectively melt-connected to the opposite sides of the fourth insulating layer 711. Details are not described herein.

[0088] It should be noted that the first conductive layer 112, the second conductive layer 312, the third conductive layer 512, and the fourth conductive layer 712 can be metallic copper or aluminum, and are not limited herein.

[0089] Refer to Figure 1 、 Figure 2 According to the battery of the above embodiment of the present utility model, including a housing and the battery cell of the first aspect embodiment of the present utility model, the battery cell is accommodated in the housing, which can improve the structural stability of the battery cell, thereby improving the electrochemical performance and use safety of the battery cell.

[0090] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0091] The above has described this embodiment in detail with reference to the drawings, but the present utility model is not limited to the above embodiment. Within the scope of knowledge possessed by those of ordinary skill in the art in the technical field, various changes can be made without departing from the gist of the present utility model.

Claims

1. A battery cell, characterized in that, Comprising: A first cell unit, including a first electrode sheet (100), a first separator (200), a second electrode sheet (300), and a second separator (400) that are sequentially stacked. The first cell unit is wound to form the cell; The first electrode sheet (100) includes a first composite current collector (110) and a first active material layer (120). The first composite current collector (110) includes a first conductive layer (112), a first insulating layer (111), and a first conductive layer (112) that are sequentially stacked. The first active material layer (120) is disposed on the corresponding first conductive layer (112); The second electrode sheet (300) includes a second composite current collector (310) and a second active material layer (320). The second composite current collector (310) includes a second conductive layer (312), a second insulating layer (311), and a second conductive layer (312) that are sequentially stacked. The second active material layer (320) is disposed on the corresponding second conductive layer (312); The opposite sides of the first separator (200) are respectively connected to the opposite sides of the first insulating layer (111), and the opposite sides of the second separator (400) are respectively connected to the opposite sides of the second insulating layer (311). The first separator (200) and the second separator (400) are both configured to isolate the corresponding first conductive layer (112) and the second conductive layer (312).

2. The battery cell according to claim 1, wherein, Along the width direction of the first cell unit, the opposite sides of the first separator (200) are respectively connected to the opposite sides of the first insulating layer (111), and the opposite sides of the second separator (400) are respectively connected to the opposite sides of the second insulating layer (311).

3. The battery cell according to claim 1, characterized in that, The opposite sides of the first separator (200) are respectively melt-connected to the opposite sides of the first insulating layer (111); The opposite sides of the second separator (400) are respectively melt-connected to the opposite sides of the second insulating layer (311).

4. The battery cell according to claim 1, characterized in that The first separator (200) includes a first connecting portion (210), a first main body portion (220), and a second connecting portion (230). The first connecting portion (210) and the second connecting portion (230) are oppositely arranged. The first connecting portion (210) is connected to the second connecting portion (230) through the first main body portion (220). The first main body portion (220) is located between the first conductive layer (112) and the corresponding second conductive layer (312). The first connecting portion (210) is connected to one side of the first insulating layer (111), and the second connecting portion (230) is connected to the opposite other side of the first insulating layer (111).

5. The battery cell according to claim 4, wherein, The widths of the first connecting portion (210) and the second connecting portion (230) are equal.

6. The battery cell according to claim 4, wherein, The width of the first connection part (210) is a, the thickness of the first conductive layer (112) is b, the thickness of the first insulating layer (111) is c, and the thickness of the first active material layer (120) is d. a, b, c, and d satisfy: b + d < a ≤ b + c + d.

7. The battery cell according to claim 4, characterized in that, One side of the first connection part (210) facing the second connection part (230) is attached to one side of the corresponding first conductive layer (112), and one side of the second connection part (230) facing the first connection part (210) is attached to the opposite side of the corresponding first conductive layer (112).

8. The battery cell according to claim 1, characterized in that, The first composite current collector (110) further includes a first connection layer (113). The first connection layer (113) is disposed on the first insulating layer (111), and the two first conductive layers (112) are electrically connected through the first connection layer (113). And / or, the second composite current collector (310) further includes a second connection layer (313). The second connection layer (313) is disposed on the second insulating layer (311), and the two second conductive layers (312) are electrically connected through the second connection layer (313).

9. A battery cell, characterized in that, Comprising: A plurality of second battery cell monomers. The second battery cell monomers include a third electrode plate (500), a third separator (600), a fourth electrode plate (700), and a fourth separator (800) that are sequentially stacked. The plurality of second battery cell monomers are sequentially stacked to form the battery cell. The third electrode plate (500) includes a third composite current collector (510) and a third active material layer (520). The third composite current collector (510) includes a third conductive layer (512), a third insulating layer (511), and a third conductive layer (512) that are sequentially stacked. The third active material layer (520) is disposed on the corresponding third conductive layer (512). The fourth electrode plate (700) includes a fourth composite current collector (710) and a fourth active material layer (720). The fourth composite current collector (710) includes a fourth conductive layer (712), a fourth insulating layer (711), and a fourth conductive layer (712) that are sequentially stacked. The fourth active material layer (720) is disposed on the corresponding fourth conductive layer (712). Opposite sides of the third separator (600) are respectively connected to opposite sides of the third insulating layer (511), and opposite sides of the fourth separator (800) are respectively connected to opposite sides of the fourth insulating layer (711). The third separator (600) and the fourth separator (800) are both configured to isolate the corresponding third conductive layer (512) and the fourth conductive layer (712).

10. The battery cell according to claim 9, wherein, Along the width direction of the second battery cell monomer, opposite sides of the third separator (600) are respectively connected to opposite sides of the third insulating layer (511), and opposite sides of the fourth separator (800) are respectively connected to opposite sides of the fourth insulating layer (711).

11. The battery cell according to claim 9, characterized in that, The opposite sides of the third diaphragm (600) are respectively and melt-connected to the opposite sides of the third insulating layer (511), and the opposite sides of the fourth diaphragm (800) are respectively and melt-connected to the opposite sides of the fourth insulating layer (711).

12. A battery, characterized in that, Comprising a housing and an electric core as described in any one of claims 1 to 11, the electric core being accommodated in the housing.

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