Battery cell, battery and electric equipment

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a battery cell, a battery and electric equipment, the battery cell comprises a first pole piece, a second pole piece and a diaphragm arranged between the first pole piece and the second pole piece, along the winding direction of the battery cell, the first pole piece comprises a plurality of first straight parts and first bent parts which are alternately arranged, and the second pole piece comprises a plurality of second straight parts and a plurality of second bent parts which are alternately arranged; the first pole piece comprises a plurality of first straight parts and a plurality of second bent parts which are alternately arranged, the second pole piece comprises a plurality of second straight parts and a plurality of second bent parts which are alternately arranged, insulating parts are arranged on the first bent parts and / or the second bent parts, the orientations of the first straight parts and the second straight parts are opposite in the innermost ring of the battery cell, and the orientations of the first straight parts and the second straight parts are opposite in the thickness direction of the battery cell. The first straight parts and the second straight parts are alternately arranged; after the battery cell is wound, the first straight parts and the second straight parts can be arranged in a one-to-one correspondence manner, and the first bent parts and the second bent parts can be arranged in a one-to-one correspondence manner, so that the thickness of the battery cell is reduced, and the waste of raw materials is reduced.

Description

Technical Field

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

[0002] As a new type of secondary battery, lithium-ion battery has the advantages of high energy density and power density, high operating voltage, light weight, small size, long cycle life, good safety, and green environmental protection. It has broad application prospects in portable appliances, power tools, large-scale energy storage, electric transportation power supply, etc.

[0003] At present, in the production process of wound cells, the separator, negative electrode sheet, separator and positive electrode sheet are generally stacked and wound in sequence to form a cell. In this way, the bent sections of the negative electrode sheet will face each other in the innermost circle of the wound cell, which not only wastes raw materials but also increases the thickness of the cell. Utility Model Content

[0004] The purpose of the utility model is to provide a battery cell, a battery and an electrical device to address the deficiencies in the prior art, thereby solving the technical problem that in the prior art, the bent sections of the negative electrode sheet are opposite to each other in the innermost circle of the wound battery cell, which not only wastes raw materials but also increases the thickness of the battery cell.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] In a first aspect, the utility model provides a battery cell, comprising a first pole piece, a second pole piece, and a diaphragm arranged between the first pole piece and the second pole piece, along the winding direction of the battery cell, the first pole piece comprises a plurality of first straight portions and first bent portions arranged alternately, the second pole piece comprises a plurality of second straight portions and second bent portions arranged alternately, an insulating member is arranged on the first bent portion and / or the second bent portion, in the innermost circle of the battery cell, the first straight portion and the second straight portion are oriented in opposite directions, and along the thickness direction of the battery cell, the first straight portion and the second straight portion are alternately arranged.

[0007] Preferably, the insulating member is located on the first bending portion and / or the second bending portion of the innermost circle of the battery core.

[0008] Preferably, in the innermost circle of the battery core, the insulating member and the orthographic projection of the first straight portion in the thickness direction of the battery core are adjacent to or partially overlapped;

[0009] And / or the insulating member is adjacent to or partially overlaps with the orthographic projection of the second straight portion in the thickness direction of the battery core.

[0010] Preferably, the upper surface of the insulating member is flush with the upper surface of the first pole piece or the upper surface of the second pole piece on which it is located.

[0011] Preferably, in the innermost circle of the battery cell, the orthographic projections of the first straight portion and the second straight portion in the thickness direction of the battery cell overlap.

[0012] Preferably, it further comprises a first pole lug and a second pole lug, wherein the first pole lug is arranged on the first pole piece, and the second pole lug is arranged on the second pole piece;

[0013] Wherein, the first pole lug is located on the first pole piece of the innermost circle of the battery cell, and the second pole lug is located on the second pole piece of the innermost circle of the battery cell;

[0014] Or, the first pole lug is located in the middle of the first pole piece, and the second pole lug is located in the middle of the second pole piece;

[0015] Or, the first pole lug and the second pole lug are both provided in plurality, and the plurality of the first pole lugs are arranged on the first pole sheet at intervals, and the plurality of the second pole lugs are arranged on the second pole sheet at intervals, and along the thickness direction of the battery cell, the plurality of the first pole lugs are stacked to form a first pole lug group, and the plurality of the second pole lugs are stacked to form a second pole lug group.

[0016] Preferably, along the winding direction of the battery cell, the first pole sheet is sequentially provided with a first double-sided coating area, a single-sided coating area and a double-sided empty foil area, and the second pole sheet is a second double-sided coating area.

[0017] Preferably, one of the first pole piece and the second pole piece is a positive pole piece, the other of the first pole piece and the second pole piece is a negative pole piece, and the insulating member is disposed on the positive pole piece.

[0018] In a second aspect, the utility model provides a battery, comprising the battery cell in the above embodiment.

[0019] In a third aspect, the utility model provides an electrical device, comprising the battery in the above embodiment.

[0020] Compared with the prior art, the beneficial effects achieved by the utility model are:

[0021] The battery cell of the embodiment of the utility model is used in combination with the first pole piece, the second pole piece and the diaphragm. The diaphragm is arranged between the first pole piece and the second pole piece to isolate the first pole piece and the second pole piece, so as to avoid the first pole piece and the second pole piece from contacting each other and causing a short circuit in the battery. By arranging the first straight portion, the first bent portion, the second straight portion and the second bent portion, in the innermost circle of the battery cell, the first straight portion and the second straight portion are oriented in opposite directions, and along the thickness direction of the battery cell, the first straight portion and the second straight portion are arranged alternately, so that after the battery cell is wound, the first straight portion and the second straight portion can be arranged one by one, and the first bent portion and the second bent portion can be arranged one by one, thereby reducing the thickness of the battery cell, saving the waste of raw materials, and simplifying the winding structure of the battery cell. By arranging an insulating member on the first bent portion and / or the second bent portion, the lithium plating caused by the error of the pole piece insertion accuracy and the insufficient overhang of the battery cell can be effectively prevented.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 It is a structural schematic diagram of the battery cell of the utility model.

[0025] Figure 2 This is a schematic structural diagram of the innermost circle of the battery cell of the utility model.

[0026] Figure 3 This is another structural schematic diagram of the battery cell of the utility model.

[0027] Figure 4 This is another structural schematic diagram of the battery cell of the utility model.

[0028] The reference numerals are described as follows:

[0029] 100. Battery cell;

[0030] 10. first pole piece; 11. first straight portion; 12. first bent portion;

[0031] 20. second pole piece; 21. second straight portion; 22. second bent portion;

[0032] 30. Diaphragm;

[0033] 40. Insulation parts;

[0034] 50. First pole lug;

[0035] 60. Second pole lug;

[0036] a. Winding direction of the battery cell; b. Thickness direction of the battery cell. DETAILED DESCRIPTION

[0037] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0038] Furthermore, the terms “first”, “second”, etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0039] In the utility model, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like 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 an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.

[0040] The following will be combined with the attached Figures 1 to 4 The technical solutions in the embodiments of the utility model are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0041] The electrical equipment of the embodiment of the utility model includes a battery. The electrical equipment may be a car, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The car may be a fuel car, a gas car, or a new energy car, and the new energy car may be a pure electric car, a hybrid car, or an extended-range car, and the like; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, and the like. The embodiment of the present application does not impose any special restrictions on the above-mentioned electrical equipment.

[0042] The battery of the embodiment of the utility model comprises a shell, a top cover and a battery cell 100. The top cover is arranged at the opening of the shell and forms an accommodation space with the shell. The battery cell 100 is arranged in the accommodation space.

[0043] See also Figures 1 to 4 The battery cell 100 of the utility model embodiment includes a first pole piece 10, a second pole piece 20 and a diaphragm 30 arranged between the first pole piece 10 and the second pole piece 20. Along the winding direction a of the battery cell 100, the first pole piece 10 includes a plurality of first straight portions 11 and first bent portions 12 arranged alternately, the second pole piece 20 includes a plurality of second straight portions 21 and second bent portions 22 arranged alternately, and an insulating member 40 is arranged on the first bent portion 12 and / or the second bent portion 22. In the innermost circle of the battery cell 100, the first straight portion 11 and the second straight portion 21 are oriented in opposite directions, and along the thickness direction b of the battery cell 100, the first straight portion 11 and the second straight portion 21 are alternately arranged.

[0044] Compared with the prior art, the battery cell 100 of the utility model embodiment uses the first pole piece 10, the second pole piece 20 and the diaphragm 30 in combination. The diaphragm 30 is arranged between the first pole piece 10 and the second pole piece 20 to isolate the first pole piece 10 and the second pole piece 20, so as to avoid the first pole piece 10 and the second pole piece 20 from contacting each other and causing a short circuit of the battery. Through the arrangement of the first straight portion 11, the first bent portion 12, the second straight portion 21 and the second bent portion 22, in the innermost circle of the battery cell 100, the first straight portion 11 and the second straight portion 21 are in opposite directions, and along the thickness direction b of the battery cell 100, the first straight portion 11 and the second straight portion 21 are arranged alternately, so that after the battery cell 100 is wound, the first straight portion 11 and the second straight portion 21 can be arranged one by one, and the first bent portion 12 and the second bent portion 22 can be arranged one by one, thereby reducing the thickness of the battery cell 100, saving the waste of raw materials, and simplifying the winding structure of the battery cell 100. By providing the insulating member 40 on the first bending portion 12 and / or the second bending portion 22 , lithium deposition caused by errors in the electrode insertion accuracy and insufficient overhang of the battery cell 100 can be effectively prevented.

[0045] It can be understood that the overhang of the battery cell 100 refers to the portion of the negative electrode sheet that is longer and wider than the positive and negative electrode sheets, which is also called excessive negative electrode design.

[0046] Furthermore, the provision of the insulating member 40 can also effectively prevent lithium deposition at the corners of the battery cell 100 during the charging cycle due to inconsistent thickness expansion between the first straight portion 11 and the first bent portion 12 and inconsistent thickness expansion between the second straight portion 21 and the second bent portion 22.

[0047] Specifically, the insulating member 40 may be disposed on the first bending portion 12 , or the insulating member 40 may be disposed on the second bending portion 22 , or both the first bending portion 12 and the second bending portion 22 may be provided with the insulating member 40 .

[0048] Specifically, the insulating member 40 is an insulating protective adhesive.

[0049] In some embodiments, the insulating member 40 is located on the first bend 12 and / or the second bend 22 of the innermost circle of the battery cell 100. By setting the insulating member 40 on the first bend 12 and / or the second bend 22 of the innermost circle of the battery cell 100, the lithium deposition caused by the error of the electrode insertion accuracy and the insufficient overhang of the battery cell 100 is effectively prevented. At the same time, since the insulating member 40 is set at the innermost circle of the battery cell 100, the burrs of the cutting port of the first electrode 10 or the second electrode 20 are effectively prevented from piercing the diaphragm 30, causing the battery cell 100 to short-circuit.

[0050] In some embodiments, in the innermost circle of the battery cell 100, the insulating member 40 is adjacent to or partially overlaps with the orthographic projection of the first straight portion 11 in the thickness direction b of the battery cell 100; and / or the insulating member 40 is adjacent to or partially overlaps with the orthographic projection of the second straight portion 21 in the thickness direction b of the battery cell 100. The safety of the battery cell 100 is effectively further enhanced. Since the insulating member 40 is adjacent to or partially overlaps with the orthographic projection of the first straight portion 11 and / or the second straight portion 21 in the thickness direction, an insulation barrier is effectively formed between the insulating member 40 and the first straight portion 11 and the second straight portion 21, thereby preventing a short circuit that may occur inside the battery cell 100.

[0051] In some embodiments, the upper surface of the insulating member 40 is flush with the upper surface of the first pole piece 10 or the upper surface of the second pole piece 20 where it is located. The flatness of the first pole piece 10 and the second pole piece 20 is effectively ensured, so that the first pole piece 10, the diaphragm 30 and the second pole piece 20 can be closely attached together, reducing the gap or misalignment caused by unevenness. At the same time, it can also improve the space utilization rate inside the battery cell 100. By making the upper surface of the insulating member 40 flush with the upper surface of the first pole piece 10 or the upper surface of the second pole piece 20 where it is located, the space inside the battery cell 100 can be maximized and unnecessary space waste can be reduced.

[0052] In some embodiments, in the innermost circle of the battery cell 100, the orthographic projections of the first straight portion 11 and the second straight portion 21 in the thickness direction b of the battery cell 100 overlap. This effectively simplifies the structure of the battery cell 100, making the battery cell 100 more compact in the thickness direction. Since the orthographic projections of the first straight portion 11 and the second straight portion 21 overlap, unnecessary space occupation can be reduced, thereby improving the energy density of the battery cell 100.

[0053] In some embodiments, the first pole piece 10 includes a first current collector and a first active material layer, and the first active material layer is disposed on at least one surface of the first current collector. The second pole piece 20 includes a second current collector and a second active material layer, and the second active material layer is disposed on at least one surface of the second current collector.

[0054] In some embodiments, the battery cell 100 further includes a first pole ear 50 and a second pole ear 60, wherein the first pole ear 50 is arranged on the first pole sheet 10, and the second pole ear 60 is arranged on the second pole sheet 20; wherein the first pole ear 50 is located on the first pole sheet 10 of the innermost circle of the battery cell 100, and the second pole ear 60 is located on the second pole sheet 20 of the innermost circle of the battery cell 100; or, the first pole ear 50 is located in the middle of the first pole sheet 10, and the second pole ear 60 is located in the middle of the second pole sheet 20; or, a plurality of the first pole ears 50 and the second pole ears 60 are each arranged, a plurality of the first pole ears 50 are arranged at intervals on the first pole sheet 10, a plurality of the second pole ears 60 are arranged at intervals on the second pole sheet 20, and along the thickness direction b of the battery cell 100, a plurality of the first pole ears 50 are stacked to form a first pole ear 50 group, and a plurality of the second pole ears 60 are stacked to form a second pole ear 60 group. The different configurations of the first pole tab 50 and the second pole tab 60 effectively increase the diversity of the position configurations of the first pole tab 50 and the second pole tab 60. In actual use, the positions of the first pole tab 50 and the second pole tab 60 can be selected according to actual needs.

[0055] In some embodiments, along the winding direction a of the battery cell 100, the first pole piece 10 is sequentially provided with a first double-sided coating area, a single-sided coating area and a double-sided empty foil area, and the second pole piece 20 is a second double-sided coating area. By providing the second active material layer on both sides of the second current collector of the second pole piece 20 from the head end to the tail end. In this way, the thickness of the first active material layer on the outer layer of the winding core can be reduced, the space of the winding core can be saved, and it is beneficial to improve the energy density of the winding core.

[0056] It can be understood that the first double-sided coating area refers to the two relative surfaces of the first current collector of the first pole piece 10 are covered with the first active material layer; the single-sided coating area refers to the two relative surfaces of the first current collector of the first pole piece 10, one of which is covered with the first active material layer, and the other surface is not covered with the first active material layer; the double-sided empty foil area refers to the two relative surfaces of the first current collector of the first pole piece 10 are not covered with the first active material layer; the second double-sided coating area refers to the two relative surfaces of the second current collector of the second pole piece 20 are covered with the second active material layer.

[0057] In some embodiments, one of the first pole sheet 10 and the second pole sheet 20 is a positive pole sheet, the other of the first pole sheet 10 and the second pole sheet 20 is a negative pole sheet, and the insulating member 40 is disposed on the positive pole sheet. If only the separator 30 is used to separate the positive pole sheet and the negative pole sheet, the lithium ions released by the positive pole can reach the negative pole through the separator 30, and the number of lithium ions released by the positive pole is greater than the receiving sites of the negative pole sheet. At this time, the lithium ions will be precipitated in the form of lithium metal, causing lithium deposition, which affects the safety and cycle performance of the battery cell 100. Therefore, the insulating member 40 is disposed at the corner of the positive pole sheet, which can effectively avoid lithium deposition at the corner of the battery cell 100.

[0058] Specifically, the first electrode sheet 10 is a positive electrode sheet, and the second electrode sheet 20 is a negative electrode sheet. Compared with the prior art, the negative electrode sheet of the embodiment of the utility model is provided with a second active material layer on both sides from the head end to the tail end, thereby reducing the thickness of the battery cell 100, saving the waste of raw materials, and further simplifying the winding structure of the battery cell 100.

[0059] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

Claims

1. A battery cell, characterized in that: The invention comprises a first pole piece (10), a second pole piece (20) and a diaphragm (30) arranged between the first pole piece (10) and the second pole piece (20); along the winding direction (a) of the battery cell (100), the first pole piece (10) comprises a plurality of first straight portions (11) and first bent portions (12) arranged alternately; the second pole piece (20) comprises a plurality of second straight portions (21) and second bent portions (22) arranged alternately; an insulating member (40) is arranged on the first bent portion (12) and / or the second bent portion (22); in the innermost circle of the battery cell (100), the first straight portion (11) and the second straight portion (21) are oriented in opposite directions; and along the thickness direction (b) of the battery cell (100), the first straight portion (11) and the second straight portion (21) are arranged alternately.

2. The battery cell according to claim 1, characterized in that: The insulating member (40) is located on the first bending portion (12) and / or the second bending portion (22) of the innermost circle of the battery core (100).

3. The battery cell according to claim 2, characterized in that: In the innermost circle of the battery core (100), the insulating member (40) and the orthographic projection of the first straight portion (11) in the thickness direction (b) of the battery core (100) are adjacent to or partially overlapped; And / or the insulating member (40) is adjacent to or partially overlaps with the orthographic projection of the second straight portion (21) in the thickness direction (b) of the battery core (100).

4. The battery cell according to claim 1, characterized in that: The upper surface of the insulating member (40) is flush with the upper surface of the first pole piece (10) or the upper surface of the second pole piece (20) on which it is located.

5. The battery cell according to claim 1, characterized in that: In the innermost circle of the battery core (100), the orthographic projections of the first straight portion (11) and the second straight portion (21) in the thickness direction (b) of the battery core (100) overlap.

6. The battery cell according to claim 1, characterized in that: It also includes a first pole lug (50) and a second pole lug (60), wherein the first pole lug (50) is arranged on the first pole piece (10), and the second pole lug (60) is arranged on the second pole piece (20); The first pole lug (50) is located on the first pole piece (10) of the innermost circle of the battery cell (100), and the second pole lug (60) is located on the second pole piece (20) of the innermost circle of the battery cell (100); Or, the first pole lug (50) is located in the middle of the first pole piece (10), and the second pole lug (60) is located in the middle of the second pole piece (20); Alternatively, a plurality of the first pole lugs (50) and a plurality of the second pole lugs (60) are provided, a plurality of the first pole lugs (50) are arranged at intervals on the first pole sheet (10), a plurality of the second pole lugs (60) are arranged at intervals on the second pole sheet (20), and along the thickness direction (b) of the battery cell (100), a plurality of the first pole lugs (50) are stacked to form a first pole lug (50) group, and a plurality of the second pole lugs (60) are stacked to form a second pole lug (60) group.

7. The battery cell according to claim 1, characterized in that: Along the winding direction (a) of the battery cell (100), the first pole piece (10) is sequentially provided with a first double-sided coating area, a single-sided coating area and a double-sided empty foil area, and the second pole piece (20) is a second double-sided coating area.

8. The battery cell according to claim 1, characterized in that: One of the first pole piece (10) and the second pole piece (20) is a positive pole piece, the other of the first pole piece (10) and the second pole piece (20) is a negative pole piece, and the insulating member (40) is arranged on the positive pole piece.

9. A battery, characterized in that: A battery cell comprising any one of claims 1 to 8.

10. An electrical equipment, characterized in that: A battery comprising the battery of claim 9.

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