Winding battery

Abstract

The utility model provides a winding battery which comprises a winding core, the winding core is formed by winding a pole piece and a diaphragm in a winding direction after being compounded, the pole piece comprises a coating area and at least one empty foil area, the pole piece has a winding state and an unfolding state, the empty foil area is located on the edge of the pole piece, and a pole lug is welded to the empty foil area; the tabs form at least one tab group when the pole piece is in a winding state, and the tabs in each tab group are pushed and pressed from the outermost layer of the winding core to the winding core shaft on the innermost layer or from the winding core shaft to the outermost layer of the winding core. According to the winding battery disclosed by the invention, the empty foil areas are arranged at the edges of the pole pieces, so that the use of foils is reduced, the production cost can be reduced and the utilization rate of the foils is improved; when the pole piece is wound, the tabs form at least one tab group, and the tab group structure can increase the number of effectively welded tabs, so that the overcurrent capacity is improved, the heat production is reduced, and the cycle performance is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of battery technology, and in particular to a wound battery. Background Art

[0002] Full-tab wound batteries are becoming more and more widely used due to their super high-rate discharge capability, stable high output voltage and ultra-long working life. They are usually used in instrumentation, medical equipment, power transmission equipment and automobiles.

[0003] Existing full-pole-ear wound batteries are generally divided into two types, one is a high-rate system cylindrical battery, and the other is a high-energy density system cylindrical battery. Among them, the positive and negative pole ears of the high-rate system cylindrical battery are respectively located at the two ends of the battery roll core, and the positive and negative pole ears of the high-energy density system cylindrical battery are located at the same end of the battery roll core. During manufacturing, the full pole ears of the foil are flattened or turned inward after the pole piece is wound, and then laser welded with the busbar. However, the inner ring pole ears of this structure have few stacked layers and are relatively thin, and are often impossible to weld; the number of effective welded pole ears is less than one-fifth of the entire pole piece length, and the welding effect is poor, resulting in insufficient actual current capacity and high temperature rise during large current charging and discharging; for high-energy density system cylindrical batteries, the full pole ears occupy a large space and cannot effectively utilize the cylindrical height space. Utility Model Content

[0004] The present disclosure provides a wound battery to at least solve the above technical problems existing in the prior art.

[0005] According to the wound battery disclosed in the present invention, it includes a winding core, which is formed by winding a pole piece and a diaphragm in a winding direction, the pole piece includes a coating area and at least one empty foil area, and the pole piece has a winding state and an unfolded state, the empty foil area is located at the edge of the pole piece, and the empty foil area is welded with a pole ear; the pole ear forms at least one pole ear group when the pole piece is in the winding state, and the pole ear in each pole ear group is set from the outermost layer of the winding core to the innermost layer of the winding core axis, or from the winding core axis to the outermost layer of the winding core.

[0006] In one possible implementation manner, the electrode sheets include a positive electrode sheet and a negative electrode sheet, the electrode tabs include a positive electrode tab and a negative electrode tab, the positive electrode tab is welded to the empty foil area of ​​the positive electrode sheet, the negative electrode tab is welded to the empty foil area of ​​the negative electrode sheet, and the winding core is wound by sequentially combining the diaphragm, the positive electrode sheet, the diaphragm and the negative electrode sheet.

[0007] In one embodiment, the positive electrode tab and the negative electrode tab are placed in the same direction so that the positive electrode tab and the negative electrode tab are located at the same end of the winding core, the electrode tab group includes a positive electrode tab group and a negative electrode tab group, the positive electrode tab group includes at least one positive electrode tab, and the negative electrode tab group includes at least one negative electrode tab.

[0008] In one possible implementation manner, the number of the negative electrode tab groups is the same as the number of the positive electrode tab groups, and the plurality of positive electrode tab groups and the plurality of negative electrode tab groups are symmetrically arranged with respect to the winding core axis.

[0009] In one possible implementation, there are a plurality of empty foil areas, and there is a gap between two adjacent empty foil areas on the positive electrode sheet, and there is a gap between two adjacent empty foil areas on the negative electrode sheet.

[0010] In one embodiment, the positive electrode tab and the negative electrode tab are placed in opposite directions so that the positive electrode tab and the negative electrode tab are respectively arranged at two ends of the winding core, and the tab group includes a positive electrode tab group and a negative electrode tab group, the positive electrode tab group includes at least one positive electrode tab, and the negative electrode tab group includes at least one negative electrode tab.

[0011] In one possible implementation, the number of the negative electrode tab groups is the same as the number of the positive electrode tab groups, and the number of the negative electrode tabs in each of the negative electrode tab groups is the same as the number of the positive electrode tabs in the corresponding positive electrode tab group.

[0012] In one possible implementation, there are multiple empty foil areas, and there is a gap between two adjacent empty foil areas on the positive electrode sheet, and there is a gap between two adjacent empty foil areas on the negative electrode sheet; or, multiple empty foil areas on the positive electrode sheet are continuously arranged, and multiple empty foil areas on the negative electrode sheet are continuously arranged.

[0013] In one possible implementation manner, the thickness of the positive electrode tab is 0.003 mm to 0.600 mm, and the thickness of the negative electrode tab is 0.003 mm to 0.600 mm.

[0014] In one embodiment, a busbar is further included, and the busbar is welded to the tab.

[0015] In the present disclosure, since there is an empty foil area at the edge of the pole piece, the use of foil is reduced, the production cost can be reduced, and the utilization rate of the foil is improved; when the pole piece is wound, the pole ears form at least one pole ear group, and the pole ear group structure can increase the number of effective welded pole ears, thereby improving the current capacity, reducing heat generation, and improving the cycle performance.

[0016] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, in which:

[0018] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0019] Figure 1 The overall structure schematic diagram of a wound battery according to an exemplary embodiment of the present disclosure is shown;

[0020] Figure 2 The figure shows a schematic diagram of the overall structure of a wound battery according to an exemplary embodiment of the present disclosure (the positive electrode tab and the negative electrode tab are both located at the same end of the winding core);

[0021] Figure 3 The figure shows a schematic diagram of the overall structure of a wound battery according to an exemplary embodiment of the present disclosure (the positive electrode tab and the negative electrode tab are respectively located at the two ends of the winding core);

[0022] Figure 4 A schematic diagram showing the unfolded state of a pole piece of a wound battery according to an exemplary embodiment of the present disclosure Figure 1 ;

[0023] Figure 5 A schematic diagram showing the unfolded state of a pole piece of a wound battery according to an exemplary embodiment of the present disclosure Figure 2 ;

[0024] Figure 6 A schematic diagram showing the unfolded state of a pole piece of a wound battery according to an exemplary embodiment of the present disclosure Figure 3 .

[0025] Explanation of the numbers in the figure: 1, pole piece; 2, pole ear group; 3, winding core; 11, coating area; 12, empty foil area; 13, pole ear; 21, positive pole ear group; 22, negative pole ear group. DETAILED DESCRIPTION

[0026] In order to make the purpose, features, and advantages of the present disclosure more obvious and easy to understand, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0027] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0028] Reference Figure 1 , Figure 4 and Figure 5 As shown, a wound battery of an embodiment of the present disclosure includes a winding core 3, which is formed by winding a pole piece 1 and a separator in a winding direction, and the pole piece 1 includes a coating area 11 and at least one empty foil area 12, and the pole piece 1 has a winding state and an unfolded state. The empty foil area 12 is located at the edge of the pole piece 1, and the empty foil area 12 is welded with a pole lug 13, and the pole lug 13 forms at least one pole lug group 2 when the pole piece 1 is in the winding state, and the pole lug 13 in each pole lug group 2 is set from the outermost layer of the winding core 3 to the innermost winding core axis, or from the winding core axis to the outermost layer of the winding core 3.

[0029] In this embodiment, taking the number of the pole lug groups 2 as eight as an example, after the pole piece 1 and the diaphragm are compositely wound to form the winding core 3, if the pole lugs 13 are all located at the same end of the winding core 3, the pole lugs 13 located at the same end of the winding core 3 form eight pole lug groups 2, and an external thrust is applied to the pole lugs 13 in these pole lug groups 2, so that the outer pole lugs 13 are pressed against the inner pole lugs 13 or the inner pole lugs 13 are pressed against the outer pole lugs 13, and it is ensured that the pole lugs 13 are pressed in the same direction; if the pole lugs 13 are located at At both ends of the winding core 3, eight pole ear groups 2 are formed at each end of the winding core 3, and external thrust is applied to the pole ears 13 at both ends of the winding core 3, so that the outer pole ears 13 are pressed against the inner pole ears 13 or the inner pole ears 13 are pressed against the outer pole ears 13, and the pole ears 13 are pressed in the same direction; after the pole ears 13 in the above-mentioned pole ear groups 2 are pushed and set, ultrasonic welding can be performed to weld the pole ears 13 in each pole ear group 2 together, so as to be subsequently welded with the busbar, thereby reducing the risk of short circuit. It can be understood that the number of pole ear groups 2 can be one or more, and the number of pole ears 13 in each pole ear group 2 can be one or more. Accordingly, one pole ear 13 corresponds to one empty foil area 12, and the length and width of each empty foil area 12 are adaptively designed according to the specifications of the required pole ears 13. When the number of empty foil areas 12 is multiple, two adjacent empty foil areas 12 are set at a certain distance, or multiple empty foil areas 12 are set continuously, that is, the entire edge of the pole ear 13 is an empty foil area 12. The coating area 11 may be an aluminum foil layer or a copper foil layer, that is, the coating area 11 may be coated with aluminum foil or copper foil, and the material of the tab 13 is a metal material such as aluminum, nickel or copper.

[0030] In the present disclosure, since the edge of the pole piece 1 has an empty foil area 12, the use of foil is reduced, the production cost can be reduced, and the utilization rate of the foil can be improved; when the pole ears 13 are all located at the same end of the winding core 3, the width of the coating area 11 of the pole piece 1 can be effectively increased, thereby increasing the capacity of the wound battery and the energy density; when the pole ears 13 are located at both ends of the winding core 3, the DC internal resistance of the wound battery can be effectively reduced, and the service life of the wound battery can be increased. Since the number of effective welded pole ears 13 of the wound battery is increased, the current passing capacity is improved, the heat generation is reduced, the cycle performance is improved, the production efficiency is improved, and the production cost is reduced.

[0031] In one embodiment, the electrode sheet 1 includes a positive electrode sheet and a negative electrode sheet, the electrode ear 13 includes a positive electrode ear and a negative electrode ear, the positive electrode ear is welded to the empty foil area 12 of the positive electrode sheet, and the negative electrode ear is welded to the empty foil area 12 of the negative electrode sheet, and the core 3 is wound by sequentially combining the diaphragm, the positive electrode sheet, the diaphragm and the negative electrode sheet.

[0032] In this embodiment, the winding core 3 is wound after being compounded with a separator, a positive electrode sheet, a separator and a negative electrode sheet in sequence. After winding, the negative electrode sheet is located at the outermost layer of the winding core 3, and the separator is located at the innermost layer of the winding core 3.

[0033] Reference Figure 2 As shown, in one embodiment, the positive electrode lug and the negative electrode lug are placed in the same direction so that the positive electrode lug and the negative electrode lug are located at the same end of the winding core 3, and the electrode lug group 2 includes a positive electrode lug group 21 and a negative electrode lug group 22, the positive electrode lug group 21 includes at least one positive electrode lug, and the negative electrode lug group 22 includes at least one negative electrode lug.

[0034] Furthermore, in one possible implementation, the number of the negative electrode tab groups 22 is the same as the number of the positive electrode tab groups 21 , and the plurality of positive electrode tab groups 21 and the plurality of negative electrode tab groups 22 are symmetrically arranged with respect to the winding core axis.

[0035] In this embodiment, multiple positive ear groups 21 and multiple negative ear groups 22 are arranged in a central symmetric manner. When the positive ear and the negative ear are concentrated at the same end of the winding core 3, there is no ear 13 on the other side of the winding core 3. At this time, the wound battery is a high energy density system battery. If the number of positive ear groups 21 and negative ear groups 22 is one, then on the end face of the winding core 3, one positive ear group 21 and one negative ear group 22 are arranged in a straight line; if the number of positive ear groups 21 and negative ear groups 22 is four, then four positive ear groups 21 and four negative ear groups 22 are arranged on both sides of the same end face of the winding core 3. Among them, the number of positive ears in each positive ear group 21 can be one or more, and the number of negative ears in each negative ear group 22 can be one or more. As a result, the width of the coating area 11 of the pole piece 1 can be effectively increased, thereby increasing the capacity of the wound battery and increasing the energy density.

[0036] Reference Figure 5 As shown, in one possible implementation, there are multiple empty foil areas 12, and there is a gap between two adjacent empty foil areas 12 on the positive electrode sheet, and there is a gap between two adjacent empty foil areas 12 on the negative electrode sheet.

[0037] In this embodiment, since the positive electrode ear is welded to the empty foil area 12 on the positive electrode sheet, and the negative electrode ear is welded to the empty foil area 12 on the negative electrode sheet, a gap is formed between two adjacent empty foil areas 12 on the positive electrode sheet or the negative electrode sheet, so that a gap is formed between two adjacent positive electrode ears or two adjacent negative electrode ears. Therefore, the gap between the electrode ears 13 can reduce the situation where the gap between the electrode ears 13 is small and affects the absorption of the electrolyte, and can effectively reduce the occurrence of insufficient battery infiltration. In addition, since there is also a gap between the electrode ear groups 2, the welding stress can be released, the strength and stability of the welding structure are increased, and the occurrence of fracture is reduced.

[0038] Reference Figure 3 As shown, in one embodiment, the positive electrode lug and the negative electrode lug are placed in opposite directions so that the positive electrode lug and the negative electrode lug are respectively arranged at both ends of the winding core 3, and the electrode lug group 2 includes a positive electrode lug group 21 and a negative electrode lug group 22, the positive electrode lug group 21 includes at least one positive electrode lug, and the negative electrode lug group 22 includes at least one negative electrode lug.

[0039] Further, in one possible implementation, the number of the negative electrode tab groups 22 is the same as the number of the positive electrode tab groups 21 , and the number of negative electrode tabs in each negative electrode tab group 22 is the same as the number of positive electrode tabs in the corresponding positive electrode tab group 21 .

[0040] In this embodiment, when the positive ear and the negative ear are respectively located at the two ends of the winding core 3, the wound battery is a high-rate system battery. The number of positive ear groups 21 and negative ear groups 22 is one or more. Taking the number of positive ear groups 21 and negative ear groups 22 as eight as an example, eight positive ear groups 21 and eight negative ear groups 22 are respectively arranged on the two end surfaces of the winding core 3, wherein the number of positive ears in each positive ear group 21 can be one or more, and the number of negative ears in each negative ear group 22 can be one or more. As a result, the DC internal resistance of the high-rate system battery can be effectively reduced, and the service life of the battery can be improved. Due to the increase in the number of effective welded pole ears 13 of the battery, the flow capacity is improved, the heat generation is reduced, the cycle performance is improved, the production rate is improved, and the production cost is reduced. It can be understood that the flow capacity of the pole ear 13 can also be increased by increasing the thickness of a single positive ear or negative ear.

[0041] Reference Figure 5 and Figure 6 As shown, in one embodiment, there are multiple empty foil areas 12, and there is a gap between two adjacent empty foil areas 12 on the positive electrode sheet, and there is a gap between two adjacent empty foil areas 12 on the negative electrode sheet. Alternatively, multiple empty foil areas 12 are continuously arranged on the positive electrode sheet, and multiple empty foil areas 12 are continuously arranged on the negative electrode sheet.

[0042] In this embodiment, the number of empty foil areas 12 can be adaptively designed according to the required battery power. When the required battery power is increased, the number of empty foil areas 12 increases; when the required battery power is reduced, the number of empty foil areas 12 decreases.

[0043] In one possible implementation, the thickness of the positive electrode tab is 0.003 mm to 0.600 mm, and the thickness of the negative electrode tab is 0.003 mm to 0.600 mm.

[0044] In this embodiment, the thickness of the positive electrode tab and the negative electrode tab can be adjusted according to the actual overcurrent requirement. The 0.003 mm and 0.600 mm here are not absolute 0.003 mm and 0.600 mm, and there can be slight deviations within the tolerance range.

[0045] In one possible implementation manner, the wound battery further includes a busbar, and the busbar is welded to the tab 13 .

[0046] In this embodiment, after the tabs 13 in the tab group 2 are pushed and set, ultrasonic welding can be performed to weld the tabs 13 in each tab group 2 together and then weld them to the busbar, thereby reducing the risk of short circuit.

[0047] In the description of the present disclosure, it is necessary to understand that the orientation or positional relationship indicated by the directional words is usually based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present disclosure and simplifying the description. Unless otherwise stated, these directional words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present disclosure; the directional words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself.

[0048] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between one or more components or features shown in the figure and other components or features. It should be understood that spatially relative terms include not only the orientation of the components as described in the figure, but also different orientations in use or operation. For example, if the components in the accompanying drawings are inverted as a whole, the components "above other components or features" or "above other components or features" will include the situation where the components are "below other components or structures" or "below other components or structures". Therefore, the exemplary term "above" may include both "above" and "below". In addition, these components or features may also be positioned at other different angles (e.g., rotated 90 degrees or other angles), and this article is intended to include all of these situations.

[0049] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, parts, components and / or combinations thereof.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein.

[0051] The present disclosure has been described through the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of example and description, and are not intended to limit the present disclosure to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present disclosure is not limited to the above-mentioned embodiments, and more variations and modifications can be made according to the teachings of the present disclosure, and these variations and modifications all fall within the scope of protection claimed by the present disclosure. The scope of protection of the present disclosure is defined by the attached claims and their equivalents.

Claims

1. A wound battery, comprising a winding core (3), wherein the winding core (3) is formed by combining a pole piece (1) and a separator and then winding the pole piece (1) along a winding direction, wherein the pole piece (1) comprises a coating area (11) and a hollow foil area (12), and the pole piece (1) has a wound state and an unfolded state, and is characterized in that: The empty foil area (12) is located at the edge of the pole piece (1), and the empty foil area (12) is welded with a pole lug (13); the pole lug (13) forms at least one pole lug group (2) when the pole piece (1) is in a wound state, and the pole lug (13) in each pole lug group (2) is pushed from the outermost layer of the winding core (3) to the innermost winding core axis, or from the winding core axis to the outermost layer of the winding core (3); The electrode sheet (1) comprises a positive electrode sheet and a negative electrode sheet, the electrode tab (13) comprises a positive electrode tab and a negative electrode tab, the positive electrode tab is welded to the empty foil area (12) of the positive electrode sheet, and the negative electrode tab is welded to the empty foil area (12) of the negative electrode sheet, the winding core (3) is wound by sequentially combining the separator, the positive electrode sheet, the separator and the negative electrode sheet, the number of the empty foil areas (12) is multiple, there is a gap between two adjacent empty foil areas (12) on the positive electrode sheet, and there is a gap between two adjacent empty foil areas (12) on the negative electrode sheet.

2. The wound battery according to claim 1, characterized in that: The positive electrode lug and the negative electrode lug are placed in the same direction so that the positive electrode lug and the negative electrode lug are located at the same end of the winding core (3); the electrode lug group (2) includes a positive electrode lug group (21) and a negative electrode lug group (22); the positive electrode lug group (21) includes at least one of the positive electrode lugs, and the negative electrode lug group (22) includes at least one of the negative electrode lugs.

3. The wound battery according to claim 2, characterized in that: The number of the negative electrode tab groups (22) is the same as the number of the positive electrode tab groups (21), and the plurality of positive electrode tab groups (21) and the plurality of negative electrode tab groups (22) are symmetrically arranged relative to the winding core axis.

4. The wound battery according to claim 1, characterized in that: The positive electrode lug and the negative electrode lug are placed in opposite directions so that the positive electrode lug and the negative electrode lug are respectively arranged at two ends of the winding core (3); the electrode lug group (2) includes a positive electrode lug group (21) and a negative electrode lug group (22); the positive electrode lug group (21) includes at least one positive electrode lug, and the negative electrode lug group (22) includes at least one negative electrode lug.

5. The wound battery according to claim 4, characterized in that: The number of the negative electrode lug groups (22) is the same as the number of the positive electrode lug groups (21), and the number of the negative electrode lugs in each negative electrode lug group (22) is the same as the number of the positive electrode lugs in the corresponding positive electrode lug group (21).

6. The wound battery according to claim 4, characterized in that: The thickness of the positive electrode ear is 0.003 mm to 0.600 mm, and the thickness of the negative electrode ear is 0.003 mm to 0.600 mm.

7. The wound battery according to claim 1, characterized in that: It also includes a busbar, which is welded to the pole lug (13).

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