Wound cell and battery

Abstract

The utility model provides a winding battery cell and a battery, the winding battery cell comprises a plurality of pole pieces and a plurality of diaphragms, the pole pieces and the diaphragms are of winding structures, the pole pieces and the diaphragms are sequentially arranged in a staggered and stacked mode, and the polarities of the pole pieces on the two sides of each diaphragm are opposite; the insulating film is arranged on the surface of the outermost pole piece or the innermost pole piece so as to separate the outermost pole piece from the innermost pole piece in the winding structure; wherein a series access is formed between the adjacent pole pieces except the outermost pole piece and the innermost pole piece, so that the output voltage of the winding battery cell can be improved, and the charging and discharging stability and the capacity of the winding battery cell are ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and specifically relates to a wound battery core and a battery. Background Art

[0002] In order to increase the output voltage of the battery, it can be achieved by connecting multiple cells in series.

[0003] However, due to the impedance differences of multiple battery cells, the charging and discharging efficiency and life of multiple battery cells are inconsistent during charging and discharging, affecting the stability of the battery; and multiple battery cells need to be connected in series through an external circuit, which reduces the utilization rate of the internal space of the battery and affects the energy density of the battery. Utility Model Content

[0004] One object of the utility model is to provide a new technical solution for winding electric cores and batteries.

[0005] According to a first aspect of the present utility model, there is provided a wound battery core, comprising:

[0006] A plurality of pole pieces and a plurality of diaphragms in a winding structure, wherein the plurality of pole pieces and the plurality of diaphragms are alternately stacked in sequence, and the pole pieces on both sides of each diaphragm have opposite polarities;

[0007] An insulating film, the insulating film being disposed on a surface of the outermost pole piece or the innermost pole piece to separate the outermost pole piece from the innermost pole piece in the winding structure;

[0008] Wherein, a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece.

[0009] Optionally, the plurality of pole pieces include a first negative pole piece, a second negative pole piece, a first positive pole piece, and a second positive pole piece, and the plurality of separators include a first separator, a second separator, and a third separator;

[0010] The first negative electrode sheet, the first positive electrode sheet, the second negative electrode sheet and the second positive electrode sheet are alternately stacked in sequence, the first separator is arranged between the first negative electrode sheet and the first positive electrode sheet, the second separator is arranged between the first positive electrode sheet and the second negative electrode sheet, and the third separator is arranged between the second negative electrode sheet and the second positive electrode sheet;

[0011] The insulating film is arranged on a side of the first negative electrode sheet away from the first separator, or is arranged on a side of the second positive electrode sheet away from the third separator, so as to separate the first negative electrode sheet and the second positive electrode sheet in the wound structure of the wound battery cell;

[0012] The first positive electrode plate and the second negative electrode plate form a series path.

[0013] Optionally, it further comprises a first negative electrode and a first positive electrode, the first negative electrode sheet has a first negative electrode tab, the first positive electrode sheet has a first positive electrode tab, the second negative electrode sheet has a second negative electrode tab, and the second positive electrode sheet has a second positive electrode tab;

[0014] The first positive electrode tab and the second negative electrode tab form a series path, and the first negative electrode tab is electrically connected to the first negative electrode, and the second positive electrode tab is electrically connected to the first positive electrode.

[0015] Optionally, a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece, comprising:

[0016] Each of the pole pieces includes a pole lug, and in the other pole pieces except the outermost pole piece and the innermost pole piece, the pole lugs of adjacent pole pieces are electrically connected.

[0017] Optionally, the wound battery cell comprises: a first electrode and a second electrode with opposite polarities;

[0018] The outermost pole piece is connected to the first electrode;

[0019] The innermost pole piece is connected to the second electrode.

[0020] Optionally, a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece, comprising:

[0021] The wound battery cell also includes a plurality of electrodes;

[0022] The plurality of pole pieces and the plurality of electrodes are connected in one-to-one correspondence;

[0023] In the other pole pieces except the outermost pole piece and the innermost pole piece, electrodes of adjacent pole pieces are electrically connected.

[0024] Optionally, one of the outermost pole piece and the innermost pole piece comprises a first current collector and a first dressing, and the first dressing is disposed on both side surfaces of the first current collector to provide active ions to the outermost pole piece or the innermost pole piece;

[0025] The first current collector is provided with through holes.

[0026] Optionally, one of the outermost pole piece and the innermost pole piece includes a second current collector and a second dressing, and the second dressing is arranged on a surface of the second current collector on a side away from the insulating film to provide active ions to the outermost pole piece or the innermost pole piece.

[0027] Optionally, the pole piece has a pole ear, and in the winding direction of the pole piece, one of the pole ears is located at the end or middle position of the pole piece.

[0028] Optionally, the pole piece has a plurality of pole ears, which are spaced apart in the extension direction of the pole piece, and starting from the winding center, the spacing between the pole ears increases successively in the winding direction, so that the plurality of pole ears on the pole piece after winding are located at the same winding radius.

[0029] According to a second aspect of the utility model, a battery is provided, which includes the wound battery cell described in the first aspect.

[0030] Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0032] Figure 1 A schematic diagram of a wound battery cell provided in one embodiment of the utility model Figure 1 ;

[0033] Figure 2 A schematic diagram of a wound battery cell provided in one embodiment of the utility model Figure 2 ;

[0034] Figure 3 A schematic diagram of a pole piece of a wound battery cell provided by an embodiment of the utility model;

[0035] Figure 4 A schematic diagram of another electrode sheet of a wound battery cell provided by an embodiment of the utility model;

[0036] Figure 5 A schematic diagram of another electrode sheet of a wound battery cell provided in one embodiment of the utility model;

[0037] Figure 6 A schematic diagram of the internal connection of a wound battery cell provided by one embodiment of the utility model;

[0038] Figure 7 A side view of a wound battery cell provided by one embodiment of the utility model;

[0039] Figure 8 A side view of another wound battery cell provided by one embodiment of the utility model;

[0040] Fig. 9 A side view of another wound battery cell provided by an embodiment of the utility model;

[0041] Fig.10 A schematic diagram of a second positive electrode sheet of a wound battery cell provided by an embodiment of the utility model;

[0042] Fig.11 A schematic diagram of a negative electrode sheet of a wound battery cell provided by an embodiment of the utility model;

[0043] Fig.12 A schematic diagram of a positive electrode sheet of a wound battery cell provided by an embodiment of the utility model;

[0044] Fig.13 A schematic diagram of a wound battery cell provided in one embodiment of the utility model Figure 3 ;

[0045] Fig.14 A schematic diagram of a wound battery cell provided in one embodiment of the utility model Figure 4 ;

[0046] Fig.15 A schematic diagram of a pole piece of another wound battery cell provided by an embodiment of the utility model;

[0047] Fig.16 A schematic diagram of a wound battery cell provided in one embodiment of the utility model Figure 5 ;

[0048] Fig.17 A schematic diagram of a wound battery cell provided in one embodiment of the utility model Figure 6 .

[0049] Wherein: 100, pole piece; 1, negative pole piece; 11, first negative pole piece; 111, first negative pole piece; 12, second negative pole piece; 121, second negative pole piece; 101, negative current collector; 102, negative electrode dressing; 13, third negative pole piece; 2, positive pole piece; 21, first positive pole piece; 211, first positive pole piece; 22, second positive pole piece; 221, second positive pole piece; 222, through hole; 201, positive current collector; 202, positive electrode dressing; 23, third positive pole piece; 3, diaphragm; 31, first diaphragm; 32, second diaphragm; 33, third diaphragm; 34, fourth diaphragm; 35, fifth diaphragm; 4, insulating film; 51, first negative electrode; 52, first positive electrode; 61, second negative electrode; 62, second positive electrode;

[0050] 200, first pole core; 300, second pole core; 400, third pole core; 500, connecting plate. DETAILED DESCRIPTION

[0051] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0052] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0053] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this application, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0054] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0055] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 this application can be understood according to specific circumstances.

[0056] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0057] An embodiment of the present application provides a wound battery cell, in which a plurality of pole pieces are arranged, and a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece, so as to increase the output voltage of the wound battery cell, facilitate high-rate charging of the wound battery cell, reduce the heat generated during charging and discharging, and ensure the stability of the wound battery cell.

[0058] Reference Figure 1 , Figure 2 and Fig.13 , the wound battery cell provided in the embodiment of the present application comprises:

[0059] A plurality of pole pieces 100 and a plurality of diaphragms 3 in a winding structure, wherein the plurality of pole pieces 100 and the plurality of diaphragms 3 are alternately stacked in sequence, and the pole pieces on both sides of each diaphragm 3 have opposite polarities;

[0060] An insulating film 4, wherein the insulating film 4 is disposed on a surface of the outermost pole piece or the innermost pole piece to separate the outermost pole piece from the innermost pole piece in the winding structure;

[0061] Wherein, a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece.

[0062] In this embodiment, the plurality of pole sheets 100 include a plurality of negative pole sheets 1 and a plurality of positive pole sheets 2 , which are alternately stacked in sequence, and each separator 3 is disposed between adjacent negative pole sheets 1 and positive pole sheets 2 .

[0063] Multiple pole pieces 100 and multiple diaphragms 3 are in a winding structure. In the stacked structure of multiple pole pieces 100 and multiple diaphragms 3, one side of the stacked structure forms a center end, and the side of the stacked structure away from the center end forms a winding end. The stacked structure is wound around the center end. Specifically, the winding end is wound around the center end, so that the center end is located at a central position in the winding structure, and the winding end is located at a peripheral position in the winding structure. When observed in a direction perpendicular to the direction in which the winding end is wound around the center end, the central position of the winding structure forms a winding center.

[0064] In this embodiment, multiple negative electrode sheets 1 and multiple positive electrode sheets 2 are alternately stacked in sequence, and may be alternately stacked in the order of one negative electrode sheet 1, one positive electrode sheet 2, one negative electrode sheet 1 and one positive electrode sheet 2 along the stacking direction, and multiple negative electrode sheets 1 and multiple positive electrode sheets 2 overlap together to increase the energy density of the wound battery cell by increasing the number of sheets in the wound battery cell.

[0065] A plurality of negative electrode sheets 1 and a plurality of positive electrode sheets 2 are alternately stacked and wound together in sequence, so as to avoid connecting a plurality of battery cells through external connectors while ensuring the energy density of the wound battery cell. Compared with the structure in which the external connectors increase the impedance between the battery cells, the wound battery cell provided in the embodiment of the present application can reduce the internal resistance of the wound battery cell and improve the charge and discharge efficiency of the wound battery cell.

[0066] After winding, multiple negative electrode sheets 1 and multiple positive electrode sheets 2 have an outermost electrode sheet and an innermost electrode sheet, wherein the innermost electrode sheet refers to the electrode sheet closest to the winding center among the stacked electrode sheets, and the outermost electrode sheet refers to the electrode sheet farthest from the winding center among the stacked electrode sheets. The polarities of the innermost electrode sheet and the outermost electrode sheet are opposite. For example, the innermost electrode sheet may be the innermost negative electrode sheet formed by the innermost negative electrode sheet 1, and the outermost electrode sheet may be the outermost positive electrode sheet formed by the outermost positive electrode sheet 2. In the winding structure, the innermost electrode sheet and the outermost electrode sheet are adjacent, and the polarities of the two are opposite. In order to prevent the wound battery cell from short-circuiting, the wound battery cell provided in the present application also includes an insulating film 4. The insulating film 4 is arranged on the surface of the innermost negative electrode sheet or the outermost positive electrode sheet to separate the innermost negative electrode sheet and the outermost positive electrode sheet in the structure of multiple wound batteries. For example, the innermost electrode sheet is a negative electrode sheet, and the outermost electrode sheet is a positive electrode sheet. An insulating film 4 can be provided on the surface of the innermost negative electrode sheet, or an insulating film 4 can be provided on the surface of the outermost positive electrode sheet. The insulating film 4 can prevent the passage of lithium ions. In the winding structure, the insulating film 4 is located between the innermost negative electrode sheet and the outermost positive electrode sheet, so the innermost negative electrode sheet and the outermost positive electrode sheet can be completely separated.

[0067] In this embodiment, a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece, which can increase the output voltage of the wound battery cell; and inside a wound battery cell, the charge and discharge currents of multiple pole pieces are equal, so that the charge and discharge efficiency and life of the multiple pole pieces can be kept consistent, thereby ensuring the charge and discharge stability of the wound battery cell.

[0068] In one embodiment, when the wound battery cell is charged at high power, a series path is formed between adjacent pole pieces to increase the end voltage of the wound battery cell. Under the same power condition, the current in each pole piece is reduced, which can effectively reduce the heat generated during the charging and discharging process of the wound battery cell.

[0069] In one embodiment, the insulating film 4 may be a diaphragm material with zero porosity to block the ion channel between the innermost negative electrode sheet and the outermost positive electrode sheet. The material of the insulating film 4 may be PP (polypropylene) or PE (polyethylene) with zero porosity.

[0070] In one embodiment, see Fig.11The negative electrode sheet 1 includes a negative electrode current collector 101 and a negative electrode dressing 102. The negative electrode dressing is coated on one side or both sides of the negative electrode current collector. The negative electrode dressing includes graphite or silicon. Fig.12 The positive electrode plate 2 includes a positive electrode current collector 201 and a positive electrode dressing 202. The positive electrode dressing is coated on one side or both sides of the positive electrode current collector. The positive electrode dressing includes one or more combinations of lithium cobalt oxide, lithium carbonate, lithium manganese oxide or ternary lithium.

[0071] In one embodiment, see Figure 1 and Figure 2 , the plurality of pole pieces include a first negative pole piece 11, a second negative pole piece 12, a first positive pole piece 21 and a second positive pole piece 22, and the plurality of separators 3 include a first separator 31, a second separator 32 and a third separator 33;

[0072] The first negative electrode sheet 11, the first positive electrode sheet 21, the second negative electrode sheet 12 and the second positive electrode sheet 22 are alternately stacked in sequence, the first separator 31 is arranged between the first negative electrode sheet 11 and the first positive electrode sheet 21, the second separator 32 is arranged between the first positive electrode sheet 21 and the second negative electrode sheet 12, and the third separator 33 is arranged between the second negative electrode sheet 12 and the second positive electrode sheet 22;

[0073] The insulating film 4 is disposed on a side of the first negative electrode sheet 11 away from the first separator 31, or on a side of the second positive electrode sheet away from the third separator 33, so as to separate the first negative electrode sheet 11 from the second positive electrode sheet 22 in the wound structure of the wound battery cell;

[0074] The first positive electrode sheet 21 and the second negative electrode sheet 12 form a series path.

[0075] In this embodiment, see Figure 6 The first diaphragm 31 and the first negative electrode sheet 11 and the first positive electrode sheet 21 on both sides thereof form a first electrode core 200, the third diaphragm 33 and the second negative electrode sheet 12 and the second positive electrode sheet 22 on both sides thereof form a second electrode core 300, and the second diaphragm 32 is arranged between the first positive electrode sheet 21 and the second negative electrode sheet 12 and separates the first electrode core 200 and the second electrode core 300.

[0076] In this embodiment, the first negative electrode sheet 11 forms the innermost negative electrode sheet, the second positive electrode sheet 22 forms the outermost positive electrode sheet, and the insulating film 4 is arranged on the side of the first negative electrode sheet 11 away from the first diaphragm 31, or the insulating film 4 is arranged on the side of the second positive electrode sheet 22 away from the third diaphragm 33, so as to separate the first negative electrode sheet 11 and the second positive electrode sheet 22 in the electrode core winding structure.

[0077] When the wound battery cell is charged and discharged, lithium ion insertion and deinsertion can be completed between the first negative electrode sheet 11 and the first positive electrode sheet 21, between the first positive electrode sheet 21 and the second negative electrode sheet 12, and between the second negative electrode sheet 12 and the second positive electrode sheet 22. In addition, the series passage formed by the first positive electrode sheet 21 and the second negative electrode sheet 12 can realize the series arrangement of the first electrode core 200 formed by the first diaphragm 31 and the first negative electrode sheet 11 and the first positive electrode sheet 21 on both sides thereof and the second electrode core 300 formed by the third diaphragm 33 and the second negative electrode sheet 12 and the second positive electrode sheet 22 on both sides thereof, so that the external output voltage of the wound battery cell is the sum of the voltages at both ends of the two electrode cores, thereby improving the output voltage and charge and discharge stability of the wound battery cell.

[0078] In one embodiment, see Fig.14 , the plurality of negative electrode sheets 1 further include a third negative electrode sheet 13, the plurality of positive electrode sheets 2 further include a third positive electrode sheet 23, and the separator 3 includes a fourth separator 34 and a fifth separator 35;

[0079] The first negative electrode sheet 11, the first positive electrode sheet 21, the second negative electrode sheet 12, the second positive electrode sheet 22, the third negative electrode sheet 13 and the third positive electrode sheet 23 are alternately stacked in sequence, the first diaphragm 31 is arranged between the first negative electrode sheet 11 and the first positive electrode sheet 21, the second diaphragm 32 is arranged between the first positive electrode sheet 21 and the second negative electrode sheet 12, and the third diaphragm 33 is arranged between the second negative electrode sheet 12 and the second positive electrode sheet 22; the fourth diaphragm 34 is arranged between the second positive electrode sheet 22 and the third negative electrode sheet, the fifth diaphragm 35 is arranged between the third negative electrode sheet and the third positive electrode sheet, and the fifth diaphragm 35 and the third negative electrode sheet 13 and the third positive electrode sheet 23 form a third pole core 400, see Fig.14 shown.

[0080] The insulating film 4 is disposed on the side of the first negative electrode sheet 11 away from the first separator 31, or the insulating film 4 is disposed on the side of the third positive electrode sheet away from the fifth separator, so as to separate the first negative electrode sheet 11 and the third positive electrode sheet in the structure of the electrode core winding. Moreover, the first positive electrode sheet 21, the second negative electrode sheet 12, the second positive electrode sheet 22 and the third negative electrode sheet 13 sequentially form a series path, so as to realize that the first electrode core 200, the second electrode core 300 and the third electrode core 400 are sequentially arranged in series, so as to further increase the end voltage of the wound battery cell.

[0081] In one embodiment, see Figure 1 , Figure 7 and Figure 8The wound cell further comprises a first negative electrode 51 and a first positive electrode 52, the first negative electrode sheet 11 has a first negative electrode tab 111, the first positive electrode sheet 21 has a first positive electrode tab 211, the second negative electrode sheet 12 has a second negative electrode tab 121, and the second positive electrode sheet 22 has a second positive electrode tab 221;

[0082] The first positive electrode tab 211 is connected to the second negative electrode tab 121 , and the first negative electrode tab 111 is electrically connected to the first negative electrode 51 , and the second positive electrode tab 221 is electrically connected to the first positive electrode 52 .

[0083] In this embodiment, a first electrode core 200 formed by a first diaphragm 31 and a first negative electrode sheet 11 and a first positive electrode sheet 21 on both sides thereof, and a second electrode core 300 formed by a third diaphragm 33 and a second negative electrode sheet 12 and a second positive electrode sheet 22 on both sides thereof are arranged inside the wound battery cell. The first electrode core 200 has a first negative electrode tab 111 and a first positive electrode tab 211 located inside the wound battery cell, and the second electrode core 300 has a second negative electrode tab 121 and a second positive electrode tab 221 located inside the wound battery cell. The connection between the first positive electrode tab 211 and the second negative electrode tab 121 can realize the series connection of the first electrode core 200 and the second electrode core 300, thereby improving the end voltage of the wound battery cell.

[0084] In this embodiment, the first negative electrode tab 111 is electrically connected to the first negative electrode 51 to form a negative terminal for connecting the wound battery cell to the outside; the second positive electrode tab 221 is electrically connected to the first positive electrode 52 to form a positive terminal for connecting the wound battery cell to the outside, and the wound battery cell can be charged through the negative terminal and the positive terminal, and the electric energy of the wound battery cell can also be output to the outside through the negative terminal and the positive terminal, so as to facilitate the external connection of the wound battery cell.

[0085] In one embodiment, a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece, including:

[0086] Each of the pole pieces includes a pole ear, and in the pole pieces other than the outermost pole piece and the innermost pole piece, the pole ears of the adjacent pole pieces are electrically connected. This implementation method simplifies the charge and discharge path of the wound battery cell and reduces the internal resistance of the wound battery cell during the charge and discharge process.

[0087] In one embodiment, see Figure 6 and Fig.16In the adjacent positive electrode sheet 2 and negative electrode sheet 1 except the outermost electrode sheet and the innermost electrode sheet, the positive electrode sheet 2 has a first positive electrode tab 211, and the negative electrode sheet 1 has a second negative electrode tab 121, and the first positive electrode tab 211 and the second negative electrode tab 121 are electrically connected, for example, the first positive electrode tab 211 and the second negative electrode tab 121 are electrically connected via a connecting plate 500.

[0088] In this embodiment, see Fig.16 and Fig.17 A plurality of negative electrode sheets 1, a plurality of positive electrode sheets 2 and a plurality of separators 3 are wound in the main body of the wound battery cell and can form a plurality of electrode cores adjacent to each other in sequence; of two adjacent electrode cores, one electrode core has a first positive electrode tab 211, and the other electrode core has a second negative electrode tab 121, and the first positive electrode tab 211 and the second negative electrode tab 121 are welded together in the main body of the wound battery cell, thereby avoiding the need to set an electrode outside the main body of the wound battery cell to connect the first positive electrode tab 211 and the second negative electrode tab 121, thereby reducing the internal resistance in the charge and discharge path of the wound battery cell.

[0089] In one embodiment, the wound battery cell comprises: a first electrode and a second electrode having opposite polarities;

[0090] The outermost pole piece is connected to the first electrode;

[0091] The innermost electrode is connected to the second electrode. The first electrode and the second electrode can respectively form a negative terminal and a positive terminal for external connection of the wound battery cell, through which the wound battery cell can be charged, and the electric energy of the wound battery cell can also be output to the outside through the negative terminal and the positive terminal.

[0092] In one embodiment, a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece, including:

[0093] The wound battery cell also includes a plurality of electrodes;

[0094] The plurality of pole pieces and the plurality of electrodes are connected in one-to-one correspondence;

[0095] In other pole pieces except the outermost pole piece and the innermost pole piece, the electrodes of adjacent pole pieces are electrically connected to form a series path between adjacent pole pieces except the outermost pole piece and the innermost pole piece, which can improve the output voltage and charge and discharge stability of the wound battery cell.

[0096] In one embodiment, a separator 3 is arranged between adjacent negative electrode sheets 1 and positive electrode sheets 2, so that one separator 3 and the adjacent negative electrode sheets 1 and positive electrode sheets 2 together form a pole core; multiple negative electrode sheets 1 and multiple positive electrode sheets 2 are alternately stacked in sequence and the adjacent negative electrode sheets 1 and positive electrode sheets 2 are separated by the separator 3 to form multiple pole cores in the wound battery cell.

[0097] In one embodiment, see Figure 8 , the first electrode may be a first negative electrode 51, the second electrode may be a second positive electrode 62, and in other electrode pieces except the outermost electrode piece and the innermost electrode piece, the plurality of electrodes corresponding to adjacent electrode pieces include a first positive electrode 52 and a second negative electrode 61;

[0098] The first negative electrode tab 111 is electrically connected to the first negative electrode 51 , and the second positive electrode tab 221 is electrically connected to the second positive electrode 62 , so as to form a negative terminal and a positive terminal of the wound cell for external connection.

[0099] The first positive electrode tab 211 is electrically connected to the first positive electrode 52 , and the second negative electrode tab 121 is electrically connected to the second negative electrode 61 , so as to form a series path between the first positive electrode tab 211 and the second negative electrode tab 121 inside the wound battery cell.

[0100] In this embodiment, in the first electrode core 200 formed by the first separator 31 inside the wound battery cell and the first negative electrode sheet 11 and the first positive electrode sheet 21 on both sides thereof, and the second electrode core 300 formed by the third separator 33 and the second negative electrode sheet 12 and the second positive electrode sheet 22 on both sides thereof, the first electrode core 200 has the above-mentioned first negative electrode tab 111 and the first positive electrode tab 211, and the first negative electrode tab 111 and the first positive electrode tab 211 serve as the negative electrode connection end and the positive electrode connection end of the first electrode core 200 respectively; the second electrode core 300 has the above-mentioned second negative electrode tab 121 and the second positive electrode tab 221, and the second negative electrode tab 121 and the second positive electrode tab 221 serve as the negative electrode connection end and the positive electrode connection end of the second electrode core 300 respectively.

[0101] The negative connection terminal of the first pole core 200 is electrically connected to the first negative electrode 51, the positive connection terminal of the first pole core 200 is electrically connected to the first positive electrode 52, the positive connection terminal of the second pole core 300 is electrically connected to the second positive electrode 62, the negative connection terminal of the second pole core 300 is electrically connected to the second negative electrode 61, and the first positive electrode 52 is electrically connected to the second negative electrode 61, so as to connect the first pole core 200 and the second pole core 300 in series; and the first negative electrode 51 and the second positive electrode 62 can directly output the electric energy of the wound battery cell, eliminating the need for electrode ear welding inside the body of the wound battery cell.

[0102] In another embodiment, see Fig. 9In the first electrode core 200 formed by the first negative electrode sheet 11 and the first positive electrode sheet 21 on both sides of the first diaphragm 31, the first negative electrode tab 111 on the first negative electrode sheet 11 serves as the negative electrode connection end of the first electrode core 200, and the first positive electrode tab 211 on the first positive electrode sheet 21 serves as the positive electrode connection end of the first electrode core 200. The negative electrode connection end of the first electrode core 200 is electrically connected to the second negative electrode 61, and the positive electrode connection end of the first electrode core 200 is electrically connected to the first positive electrode 52; the third diaphragm 33 and the second negative electrode sheets 12 and the second positive electrode sheets 22 on both sides thereof form In the second electrode core 300, the second negative electrode tab 121 on the second negative electrode sheet 12 serves as the negative electrode connection terminal of the second electrode core 300, and the second positive electrode tab 221 on the second positive electrode sheet 22 serves as the positive electrode connection terminal of the second electrode core 300. The positive electrode connection terminal of the second electrode core 300 is electrically connected to the second positive electrode 62, the negative electrode connection terminal of the second electrode core 300 is electrically connected to the first negative electrode 51, and the first positive electrode 52 is electrically connected to the first negative electrode 51, so as to connect the first electrode core 200 and the second electrode core 300 in series, thereby ensuring the stability of the series connection path formed by multiple electrode cores in the wound battery cell.

[0103] In one embodiment, multiple negative electrode sheets 1 include a third negative electrode sheet having a third negative electrode tab, multiple positive electrode sheets 2 include a third positive electrode sheet having a third positive electrode tab, a fourth diaphragm is disposed between the second positive electrode sheet 22 and the third negative electrode sheet, and a fifth diaphragm is disposed between the third negative electrode sheet and the third positive electrode sheet, so as to form a third electrode core 400 by the fifth diaphragm, the third negative electrode sheet and the third positive electrode sheet.

[0104] The first positive electrode tab 211 and the second negative electrode tab 121 are welded together within the body of the wound battery cell, and the second positive electrode tab and the third negative electrode tab are connected through electrodes outside the body of the wound battery cell to form a combination of direct electrical connection and connection through electrodes between adjacent pole pieces except the outermost pole piece and the innermost pole piece, which can also ensure the stability of the first pole core 200, the second pole core 300 and the third pole core 400 connected in series in sequence.

[0105] In one embodiment, one of the outermost pole piece and the innermost pole piece includes a first current collector and a first dressing, and the first dressing is disposed on both side surfaces of the first current collector to provide active ions to the outermost pole piece or the innermost pole piece;

[0106] The first current collector is provided with through holes.

[0107] In one embodiment, see Fig.10, the outermost electrode sheet may be a second positive electrode sheet 22, the second positive electrode sheet 22 includes a first positive electrode collector and a first positive electrode dressing, the first positive electrode dressing is arranged on both side surfaces of the first positive electrode collector, so as to provide active ions to the second positive electrode sheet 22;

[0108] The first positive electrode current collector is provided with a through hole 222 .

[0109] In this embodiment, since the side of the second positive electrode plate 22 close to the insulating film 4 is blocked by the insulating film 4, the ions in the first positive electrode dressing on the side of the second positive electrode plate 22 close to the insulating film 4 cannot be exchanged; and the through hole 222 can connect the two side surfaces of the first positive electrode collector to connect the first positive electrode dressing on the two side surfaces of the first positive electrode collector into one, so as to facilitate the first positive electrode dressing on the two side surfaces of the first positive electrode collector and the second negative electrode dressing on the second negative electrode plate to perform ion exchange through the third separator 33.

[0110] In one embodiment, one of the outermost pole piece and the innermost pole piece includes a second current collector and a second dressing, and the second dressing is arranged on a surface of the second current collector away from the insulating film to provide active ions to the outermost pole piece or the innermost pole piece.

[0111] In one embodiment, the outermost electrode sheet can be a second positive electrode sheet 22, which includes a second positive electrode collector and a second positive electrode dressing. The second positive electrode dressing is arranged on a side surface of the second positive electrode collector away from the insulating film to provide active ions to the second positive electrode sheet 22.

[0112] In this embodiment, since the side of the second positive electrode sheet 22 close to the insulating film is blocked by the insulating film 4, the second positive electrode dressing may not be provided on the side of the second positive electrode sheet 22 close to the insulating film 4, and the second positive electrode dressing may be provided only on the surface of the side of the second positive current collector away from the insulating film, so as to ensure the effective utilization of the positive electrode dressing in the wound battery cell.

[0113] In one embodiment, the pole piece has a pole ear, and in the winding direction of the pole piece, the pole ear is located at the end or the middle of the pole piece.

[0114] In one embodiment, see Figure 3 and Figure 4 The electrode sheet includes a negative electrode sheet 1 and a positive electrode sheet 2, the negative electrode sheet 1 includes a first negative electrode sheet 11 and a second negative electrode sheet 12, the positive electrode sheet 2 includes a first positive electrode sheet 21 and a second positive electrode sheet 22, the first negative electrode sheet 11 has a first negative electrode ear 111, one end of the first negative electrode sheet 11 forms a fixed end, and a side of the first negative electrode sheet 11 away from the fixed end forms a winding end, such as Figure 3The right end of the first negative electrode sheet 11 is the fixed end of the first negative electrode sheet 11. Figure 3 The left end of the first negative electrode sheet 11 is the winding end of the first negative electrode sheet 11, and the winding end of the first negative electrode sheet 11 is wound around the fixed end of the first negative electrode sheet 11; in the winding direction from the fixed end of the first negative electrode sheet 11 to the winding end of the first negative electrode sheet 11, a first negative electrode tab 111 is located at the end or middle position of the first negative electrode sheet 11. The first negative electrode tab 111 can form a port for external connection of the first negative electrode sheet 11, which is convenient for external connection of the wound battery cell.

[0115] See also Figure 3 and Figure 4 The first positive electrode sheet 21 has a first positive electrode ear 211, the second negative electrode sheet 12 has a second negative electrode ear 121, and the second positive electrode sheet 22 has a second positive electrode ear 221. In the winding direction of the electrode sheets in the wound battery cell, the first positive electrode ear 211 is located at the end or middle position of the first positive electrode sheet 21, the second negative electrode ear 121 is located at the end or middle position of the second negative electrode sheet 12, and the second positive electrode ear 221 is located at the end or middle position of the second positive electrode sheet 22.

[0116] In one embodiment, see Figure 3 The first negative electrode tab 111 is located at the fixed end of the first negative electrode sheet 11, the first positive electrode tab 211 is located at the fixed end of the first positive electrode sheet 21, the second negative electrode tab 121 is located at the fixed end of the second negative electrode sheet 12, and the second positive electrode tab 221 is located at the fixed end of the second positive electrode sheet 22. In the structure in which the first negative electrode sheet 11, the first positive electrode sheet 21, the second negative electrode sheet 12 and the second positive electrode sheet 22 are alternately stacked in sequence, the first positive electrode tab 211 and the second negative electrode tab 121 are relatively stacked together to facilitate electrical connection between the first positive electrode sheet 21 and the second negative electrode sheet 12.

[0117] In one embodiment, see Figure 4, the first negative electrode tab 111 is located in the middle of the first negative electrode sheet 11, and a first distance is formed between the first negative electrode tab 111 and the fixed end of the first negative electrode sheet 11, the first positive electrode tab 211 is located in the middle of the first positive electrode sheet 21, and a second distance is formed between the first positive electrode tab 211 and the fixed end of the first positive electrode sheet 21, the second negative electrode tab 121 is located in the middle of the second negative electrode sheet 12, and a third distance is formed between the second negative electrode tab 121 and the fixed end of the second negative electrode sheet 12, and the second positive electrode tab 221 is located in the middle of the second positive electrode sheet 22, And a fourth distance is formed between the second positive electrode ear 221 and the fixed end of the second positive electrode sheet 22, the fourth distance is greater than the third distance, the third distance is greater than the second distance, and the second distance is greater than the first distance. In the structure in which the first negative electrode sheet 11, the first positive electrode sheet 21, the second negative electrode sheet 12 and the second positive electrode sheet 22 are alternately stacked in sequence, the first positive electrode ear 211 and the second negative electrode ear 121 are relatively stacked together. Similarly, on the basis of facilitating the electrical connection between the first positive electrode sheet 21 and the second negative electrode sheet 12, electricity can be conducted to the two sides of the corresponding electrode sheet through the ear, thereby improving the conductivity efficiency of the electrode sheet.

[0118] In one embodiment, the pole piece has a plurality of pole ears, which are spaced apart in the extension direction of the pole piece, and starting from the winding center, the spacing between the pole ears increases successively in the winding direction, so that the plurality of pole ears on the pole piece after winding are located at the same winding radius.

[0119] In one embodiment, see Fig.15 The electrode sheet includes a negative electrode sheet 1 and a positive electrode sheet 2, the negative electrode sheet 1 includes a first negative electrode sheet 11 and a second negative electrode sheet 12, the positive electrode sheet 2 includes a first positive electrode sheet 21 and a second positive electrode sheet 22, the first negative electrode sheet 11 has a plurality of first negative electrode tabs 111, the plurality of first negative electrode tabs 111 are arranged at intervals in the extension direction of the first negative electrode sheet 11, and one end of the first negative electrode sheet 11 forms a fixed end, and an end of the first negative electrode sheet 11 away from the fixed end forms a winding end, and the first The winding end of a negative electrode sheet 11 is wound around the fixed end of the first negative electrode sheet 11, so that the fixed end of the first negative electrode sheet 11 forms the winding center of the first negative electrode sheet 11, and starting from the winding center of the first negative electrode sheet 11, in the winding direction from the fixed end of the first negative electrode sheet 11 to the winding end of the first negative electrode sheet 11, the spacing between adjacent first negative electrode ears 111 increases successively, so that the multiple first negative electrode ears 111 on the wound first negative electrode sheet 11 are located at the same winding radius.

[0120] In this embodiment, the first negative electrode sheet 11 after winding forms a multi-turn winding structure from the inside to the outside, in which the circumference of the outer coil is greater than the length of the inner coil, and a first negative electrode tab 111 is arranged on each coil; in the winding direction from the fixed end of the first negative electrode sheet 11 to the winding end of the first negative electrode sheet 11, the spacing between adjacent first negative electrode tabs 111 increases successively, so that the first negative electrode tabs 111 on each coil in the multi-turn winding structure can overlap, so as to facilitate welding of multiple first negative electrode tabs 111 together.

[0121] In one embodiment, the first positive electrode sheet 21 has a plurality of first positive electrode tabs 211, the second negative electrode sheet 12 has a plurality of second negative electrode tabs 121, and the second positive electrode sheet 22 has a plurality of second positive electrode tabs 221; and starting from the winding center formed by the fixed end of the first positive electrode sheet 21, in the winding direction from the fixed end of the first positive electrode sheet 21 to the winding end of the first positive electrode sheet 21, the spacing between adjacent first positive electrode tabs 211 increases successively; starting from the winding center formed by the fixed end of the second negative electrode tab 121, in the winding direction from the fixed end of the first positive electrode sheet 21 to the winding end of the first positive electrode sheet 21, the spacing between adjacent first positive electrode tabs 211 increases successively; starting from the winding center formed by the fixed end of the second negative electrode tab 121, in the winding direction from the fixed end of the first positive electrode sheet 21 to the winding end of the first positive electrode sheet 21, the spacing between adjacent first positive electrode tabs 211 increases successively; In the winding direction from the fixed end of the second positive electrode tab 221 to the winding end of the second negative electrode tab 121, the spacing between adjacent second negative electrode tabs 121 increases successively; starting from the winding center formed by the fixed end of the second positive electrode tab 221, in the winding direction from the fixed end of the second positive electrode tab 221 to the winding end of the second positive electrode tab 221, the spacing between adjacent second positive electrode tabs 221 increases successively, so as to facilitate the connection of multiple first positive electrode tabs 211 after overlapping, the connection of multiple second negative electrode tabs 121 after overlapping, and the connection of the second positive electrode tab 221 after overlapping.

[0122] In one embodiment, see Figure 5 The electrode sheet includes a negative electrode sheet 1 and a positive electrode sheet 2, the negative electrode sheet 1 includes a first negative electrode sheet 11 and a second negative electrode sheet 12, the positive electrode sheet 2 includes a first positive electrode sheet 21 and a second positive electrode sheet 22, the first negative electrode sheet 11 has a plurality of first negative electrode tabs 111, and the plurality of first negative electrode tabs 111 are arranged at equal intervals on the first negative electrode sheet 11; the first positive electrode sheet 21 has a plurality of first positive electrode tabs 211, and the plurality of first positive electrode tabs 211 are arranged on the first positive electrode sheet 2 1 is arranged at equal intervals; the second negative electrode sheet 12 has a plurality of second negative electrode tabs 121, and the plurality of second negative electrode tabs 121 are arranged at equal intervals on the second negative electrode sheet 12; the second positive electrode sheet 22 has a plurality of second positive electrode tabs 221, and the plurality of second positive electrode tabs 221 are arranged at equal intervals on the second positive electrode sheet 22, so as to facilitate the cutting or welding of the tabs on the first negative electrode sheet 11, the second negative electrode sheet 12, the first positive electrode sheet 21 and the second positive electrode sheet 22.

[0123] An embodiment of the present application also provides a battery, which includes one or more wound battery cells as mentioned above.

[0124] In this embodiment, when a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece in the wound battery cell of the battery, the output voltage of the wound battery cell can be improved, the charge and discharge efficiency and life of adjacent pole pieces can be kept consistent, and the pairing of parameters such as the end voltage and resistance between different battery cells when connected in series is avoided, thereby ensuring the charge and discharge stability of the battery.

[0125] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A wound battery cell, comprising: A plurality of pole pieces and a plurality of diaphragms in a winding structure, wherein the plurality of pole pieces and the plurality of diaphragms are alternately stacked in sequence, and the pole pieces on both sides of each diaphragm have opposite polarities; An insulating film, the insulating film being disposed on a surface of the outermost pole piece or the innermost pole piece to separate the outermost pole piece from the innermost pole piece in the winding structure; Wherein, a series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece.

2. The wound battery cell according to claim 1, characterized in that: The plurality of pole pieces include a first negative pole piece, a second negative pole piece, a first positive pole piece, and a second positive pole piece, and the plurality of separators include a first separator, a second separator, and a third separator; The first negative electrode sheet, the first positive electrode sheet, the second negative electrode sheet and the second positive electrode sheet are alternately stacked in sequence, the first separator is arranged between the first negative electrode sheet and the first positive electrode sheet, the second separator is arranged between the first positive electrode sheet and the second negative electrode sheet, and the third separator is arranged between the second negative electrode sheet and the second positive electrode sheet; The insulating film is arranged on a side of the first negative electrode sheet away from the first separator, or is arranged on a side of the second positive electrode sheet away from the third separator, so as to separate the first negative electrode sheet and the second positive electrode sheet in the wound structure of the wound battery cell; The first positive electrode plate and the second negative electrode plate form a series path.

3. The wound battery cell according to claim 2, characterized in that: It also includes a first negative electrode and a first positive electrode, the first negative electrode sheet has a first negative electrode tab, the first positive electrode sheet has a first positive electrode tab, the second negative electrode sheet has a second negative electrode tab, and the second positive electrode sheet has a second positive electrode tab; The first positive electrode tab and the second negative electrode tab form a series path, and the first negative electrode tab is electrically connected to the first negative electrode, and the second positive electrode tab is electrically connected to the first positive electrode.

4. The wound battery cell according to claim 1, characterized in that: A series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece, including: Each of the pole pieces includes a pole lug, and in the other pole pieces except the outermost pole piece and the innermost pole piece, the pole lugs of adjacent pole pieces are electrically connected.

5. The wound battery cell according to claim 4, characterized in that: The wound battery cell comprises: a first electrode and a second electrode with opposite polarities; The outermost pole piece is connected to the first electrode; The innermost pole piece is connected to the second electrode.

6. The wound battery cell according to claim 1, characterized in that: A series path is formed between adjacent pole pieces except the outermost pole piece and the innermost pole piece, including: The wound battery cell also includes a plurality of electrodes; The plurality of pole pieces and the plurality of electrodes are connected in one-to-one correspondence; In other pole pieces except the outermost pole piece and the innermost pole piece, electrodes of adjacent pole pieces are electrically connected.

7. The wound battery cell according to claim 1, characterized in that: One of the outermost pole piece and the innermost pole piece comprises a first current collector and a first dressing, wherein the first dressing is disposed on both side surfaces of the first current collector to provide active ions to the outermost pole piece or the innermost pole piece; The first current collector is provided with through holes.

8. The wound battery cell according to claim 1, characterized in that: One of the outermost pole piece and the innermost pole piece includes a second current collector and a second dressing, wherein the second dressing is disposed on a surface of the second current collector away from the insulating film to provide active ions to the outermost pole piece or the innermost pole piece.

9. The wound battery cell according to claim 1, characterized in that: The pole piece is provided with a pole ear, and in the winding direction of the pole piece, one of the pole ears is located at the end or the middle position of the pole piece.

10. The wound battery cell according to claim 1, characterized in that: The pole piece has a plurality of pole ears, which are spaced apart in the extension direction of the pole piece, and starting from the winding center, the spacing between the pole ears increases successively in the winding direction, so that the plurality of pole ears on the pole piece after winding are located at the same winding radius.

11. A battery, characterized in that: The invention comprises a wound battery cell as described in any one of claims 1 to 10.

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