Pole piece structure for solving rolling belt breakage

Abstract

The utility model relates to the technical field of battery manufacturing, in particular to a pole piece structure for solving the problem of belt breakage during rolling, which comprises a current collector, an active material layer and a prefabricated transfer piece, compared with the prior art, the width of an empty foil area in the current collector is shortened, the belt breakage rate of a pole piece during rolling is reduced, the production efficiency is improved, and meanwhile, the production cost is reduced. And waste materials generated during cutting of the empty foil area during die cutting are reduced, and material waste is avoided. In addition, the prefabricated adapter plate is made of a metal foil material, so that the thickness of an empty foil area is prevented from being too large after the pole pieces are stacked, and the overall energy density of the battery is not influenced. And the prefabricated adapter plate can be arranged on one surface or two surfaces of the tab region, so that the connection stability with the pole is further ensured. The improvements significantly improve the production efficiency, the material utilization rate and the connection reliability of the pole piece.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of battery manufacturing, especially relates to a kind of pole piece structure of solving roll break. BACKGROUND

[0002] As the important component of battery, pole piece mainly includes current collector and active material layer arranged on current collector. In the existing pole piece preparation technology, active material in pole piece is compounded in the coverage area of current collector, then the pole piece is rolled to make active material layer compact and dense. Subsequently, the pole piece is die-cut, and the tab is cut out in the empty foil area of current collector without compounded active material layer, to realize the external connection of pole piece.

[0003] However, due to the inconsistent thickness of the empty foil area and the coverage area of the tab, the pole piece is prone to break during rolling, which often occurs when using thinner foil, the active material layer is compacted thicker or the empty foil area is reserved wider. In addition, in order to reserve the tab area, the foil needs to be significantly wider than the coverage area during coating the pole piece. After die-cutting, a large amount of foil in the empty foil area without covered active material layer is treated as waste, causing waste of foil, especially when the length of the tab is longer, the waste is more serious. SUMMARY

[0004] To solve the above technical problems, the utility model provides a kind of pole piece structure of solving roll break, reduce the breakage rate of pole piece, also reduce the waste of material. The technical scheme of the utility model is as follows:

[0005] The utility model provides a kind of pole piece structure of solving roll break, including current collector, active material layer, prefabricated adapter piece.

[0006] Specifically, the current collector includes empty foil area and coverage area, the active material layer is arranged above the coverage area, and the prefabricated adapter piece is connected with the empty foil area.

[0007] Specifically, the empty foil area includes die-cutting area and tab area, the prefabricated adapter piece includes tab welding area and tab extension area, one end of the tab welding area is welded with the tab area, and the other end of the tab welding area is connected with the tab extension area.

[0008] Specifically, the width of the prefabricated adapter piece is the same as the width of the tab area, and the prefabricated adapter piece is arranged on one side or both sides of the tab area.

[0009] Specifically, the prefabricated adapter piece is metal foil.

[0010] Specifically, the length of the empty foil area is 3mm-10mm.

[0011] Specifically, the tab welding area is arranged on the tab area, and the tab extension area extends from the tab area.

[0012] Specifically, the length of the tab welding area is 1mm-10mm.

[0013] Specifically, the thickness of the tab welding area is 8um-20um.

[0014] Specifically, the thickness of the tab extension area is 8um-20um.

[0015] Specifically, the length of the prefabricated adapter piece is 5mm-40mm.

[0016] Specifically, the length of the tab extension area is 5mm-40mm.

[0017] The advantages of the utility model are as follows:

[0018] 1. By reducing the width of the empty foil area, the strip breaking rate of the pole piece during rolling is significantly reduced, and the production efficiency and product quality are improved.

[0019] 2. Because the width of the empty foil area is shortened, the waste material cut during die cutting is less, the material waste is significantly reduced, and the material utilization rate is improved.

[0020] 3. In the welding process, because the prefabricated adapter piece has the same width as the tab area, the prefabricated adapter piece does not need to be cut again, further reducing material waste and simplifying the production process.

[0021] 4. The prefabricated adapter piece is made of metal foil material, which not only enhances flexibility and bendability, but also avoids excessive thickness of the empty foil area after stacking the pole piece, ensuring that the overall energy density of the battery is not affected. At the same time, it is convenient for the welding of the prefabricated adapter piece and the empty foil area, and ensures the reliability of the connection.

[0022] 5. The prefabricated adapter piece can be arranged on one side or both sides of the tab area, enhancing the stability of the connection with the pole, and adapting to different design requirements. DRAWINGS

[0023] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are only one embodiment of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor on the premise of the drawings.

[0024] Wherein the same parts are denoted by the same reference signs. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the words "bottom" and "top", "inner" and "outer" refer to the directions towards or away from the geometric center of the specific part, respectively.

[0025] Figure 1 The exploded view of the current collector and the prefabricated adapter piece in the embodiment of the present application;

[0026] Figure 2 The schematic diagram of the pole piece finished product in the embodiment of the present application;

[0027] Figure 3 The schematic diagram of the pole piece from another perspective in the embodiment of the present application.

[0028] In the above drawings, the meanings of the reference signs are as follows:

[0029] 1, current collector

[0030] 11, coverage area;

[0031] 12, empty foil area;

[0032] 121, die-cutting area;

[0033] 122, pole lug area;

[0034] 2, prefabricated adapter piece;

[0035] 21, pole lug welding area;

[0036] 22, pole lug extension area;

[0037] 3, active material layer. DETAILED DESCRIPTION

[0038] The technical solutions of the present application will be described clearly and completely below in combination with the embodiments of the present application and the drawings thereof. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as those commonly understood by those skilled in the art to which the present application belongs; the terms used in the specific embodiments are only for the purpose of describing the specific embodiments, and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above drawing description are intended to cover the non-exclusive inclusion.

[0040] In the description of the specific embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is more than two, unless otherwise explicitly specified.

[0041] In the present application, "embodiment" means that the specific features, structures or characteristics described in combination with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0042] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents a "or" relationship between the front and rear associated objects.

[0043] Throughout the present application, numerical values represent an approximate measure or limit of a range to encompass minor deviations from the given value and embodiments with approximately the mentioned values and embodiments with the mentioned exact values. In addition to the working examples provided at the end of the specific embodiments, all numerical values of the parameters such as quantities or conditions in the appended claims are understood to be modified by the term "about" in all cases, regardless of whether "about" is actually present before the numerical value. "About" indicates that the stated numerical value allows some slight inaccuracy from the exact value of the stated value; approximately or reasonably close to the stated value; almost. If the inaccuracy provided by "about" is not otherwise understood in the art in this ordinary meaning, "about" as used in the present application at least indicates the variation that can be produced by ordinary methods of measuring and using such parameters. For example, "about" can include a variation of less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in some aspects, optionally less than or equal to 0.1%.

[0044] In addition, the disclosure of a range includes all values within the range and the disclosure of a further divided range, including the endpoints and subranges given for these ranges.

[0045] The embodiments of the present application will be described in more detail by the following examples. It should be noted that the embodiments of the present application are not limited to these examples.

[0046] Embodiments

[0047] In a specific embodiment, as shown in Figure 1 and Figure 2 A pole piece structure solving the problem of broken belt during rolling, comprising a current collector 1, an active material layer 3, and a prefabricated adapter piece 2, the current collector 1 comprises a blank foil area 12 and a covered area 11, the active material layer 3 is arranged above the covered area 11, and the prefabricated adapter piece 2 is connected with the blank foil area 12; the blank foil area 12 comprises a die-cut area 121 and a tab area 122, the prefabricated adapter piece 2 comprises a tab welding area 21 and a tab extension area 22, one end of the tab welding area 21 is welded with the tab area 122, and the other end of the tab welding area 21 is connected with the tab extension area 22; the width of the prefabricated adapter piece 2 is the same as the width of the tab area 122.

[0048] Specifically, the width of the prefabricated adapter piece 2 and the width of the tab area 122 are Figure 1 the length in the X direction.

[0049] Through the above arrangement, the present application significantly reduces the broken belt rate of the pole piece during rolling by reducing the width of the blank foil area 12. Moreover, when the pole piece is die-cut, the waste material is less due to the short width of the blank foil area 12, thereby reducing material waste.

[0050] In addition, the present application adopts the prefabricated adapter piece 2 with the same width as the tab area 122 to weld with the tab area 122, and no further cutting of the adapter piece is required after welding, thereby avoiding material waste.

[0051] Moreover, the prefabricated adapter piece 2 can be directly cut from the material foil according to the shape and size requirements, thereby avoiding material waste.

[0052] In the present application, the pole piece can be a positive pole piece or a negative pole piece. When the pole piece is a positive pole piece, the active material in the active material layer 3 is a positive active material; when the pole piece is a negative pole piece, the active material in the active material layer 3 is a negative active material.

[0053] In some embodiments, the prefabricated adapter piece 2 is a metal foil. The prefabricated adapter piece 2 is a metal foil, which is thin in thickness and good in flexibility, and is easy to bend. On the one hand, the ultra-thin metal foil can avoid the overall thickness of the blank foil area 12 being greater than the overall thickness of the corresponding area of the active material layer 3 after the pole pieces are stacked, thereby affecting the energy density of the battery as a whole. On the other hand, it is convenient to weld with the blank foil 12 area, realize the connection of the pole piece and the pole, and ensure the connection reliability of the blank foil area 12.

[0054] In some embodiments, the pre-made adapter piece 2 is a metal foil, and the pre-made adapter piece has the same material as the empty foil area 12, which is conducive to improving the strength of the welding and ensuring good electrical conductivity. For example, the pre-made adapter piece 2 and the empty foil area 12 are both aluminum foils.

[0055] In some embodiments, the length L1 of the empty foil area 12 is 3mm-10mm. As shown in Figure 1 As shown in Figure 1 The length of the above-mentioned empty foil area 12 is the length in the y direction.

[0056] In practical applications, the length of the empty foil area 12 can be selected as 3mm, 5mm, 8mm, or 10mm, and the above values are only examples and are not limited.

[0057] In the utility model, by strictly controlling the width of the empty foil area 12, compared with the prior art, the width of the empty foil area 12 is reduced, so that the pole piece avoids appearing wrinkles when rolling, the production quality of the lug is improved, and the connection reliability of the lug is improved.

[0058] In the utility model, if the width of the empty foil area 12 is too small, it is not convenient to weld other objects capable of conducting electricity outward in the empty foil area 12, and the electrical connection with the pole cannot be realized; if the width of the empty foil area 12 is too large, the belt is prone to breakage when rolling.

[0059] In some embodiments, the lug welding area 21 of the pre-made adapter piece 2 is arranged on the lug area 122 of the empty foil area 12 of the current collector 1, and the lug welding area 21 is welded with the lug area 122. The lug extension area 22 of the pre-made adapter piece 2 extends from the current collector 1 and is used for connecting other adapter conductive parts or structures capable of conducting electricity outward of the battery to realize the external conduction of the battery.

[0060] Specifically, the structure capable of conducting electricity outward can be a pole on a square case battery top cover assembly, an adapter aluminum bar, or an adapter copper bar; the end of the lug extension area 22 away from the lug adapter area can be directly welded on the end of the pole facing the inside of the battery, or can be connected to the end of the pole facing the inside of the battery through the adapter aluminum bar or the adapter copper bar to realize the external conduction of the battery.

[0061] It can also be a pre-made lug packaged together with an aluminum plastic film in a soft package assembly, one end of the pre-made lug is located in the aluminum plastic film and is welded with the lug extension area 22, the other end of the pre-made lug extends from the aluminum plastic film, and the pre-made lug is plastic encapsulated with the aluminum plastic film through the lug glue to realize the external conduction of the battery.

[0062] In some embodiments, the length of the lug welding area 21 is 1mm-10mm, and the lug welding area 21 is used for welding with the lug area 122 on the current collector.

[0063] In practical applications, the length of the tab welding area 21 can be selected as 1 mm, 4 mm, 5 mm, 8 mm, or 10 mm. The above values are only examples and are not limited.

[0064] In some embodiments, the thickness of the tab welding area 21 is 8 μm-20 μm.

[0065] In practical applications, the thickness of the tab welding area 21 can be selected as 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, or 20 μm. The above values are only examples and are not limited.

[0066] In some embodiments, the thickness of the tab extension area 22 is 8 μm-20 μm.

[0067] In practical applications, the thickness of the tab extension area 22 can be selected as 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, or 20 μm. The above values are only examples and are not limited.

[0068] In some embodiments, the length of the prefabricated adapter tab 2 is 5 mm-40 mm.

[0069] In practical applications, the length of the prefabricated adapter tab 2 can be selected as 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, or 40 mm. The above values are only examples and are not limited.

[0070] Through the above setting, the connection strength of the tab and the external conductive structure can be ensured. If the length is less than the range, it is not convenient to realize the welding of the prefabricated adapter tab and the tab area 122 on the current collector 1, which affects the connection strength of the prefabricated adapter tab 2 and the tab area 122. Moreover, if the length is less than the range, the tab area 122 on the current collector 1 cannot be extended, which is not convenient to realize the connection of the prefabricated adapter tab 2 and the external conductive structure, thereby affecting the connection strength of the tab and the external conductive structure. If the length is greater than the range, the connection structure between the tab and the external conductive structure is too long, which will occupy the internal space of the battery, causing space waste, and even the volume energy density of the battery.

[0071] Specifically, the external conductive structure can be a pole on a square cell battery, an adapter aluminum bar, an adapter copper bar, or a prefabricated tab on a soft package battery.

[0072] In practical applications, the length of the tab extension area 22 can be selected as 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, or 40 mm. The above values are only examples and are not limited.

[0073] In some embodiments, as shown in FIG. 1, the prefabricated adapter tab 2 is arranged on at least one side of the tab area 122. Figure 3 ​

[0074] In some embodiments, as shown in Figure 3 Both sides of the tab area 122 are provided with prefabricated adapter plates 2.

[0075] By providing prefabricated adapter plates 2 on both sides of the tab area, the stability of the connection between the tab and the external conductive structure can be ensured.

[0076] It should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An electrode structure solving the problem of strip breakage by roll pressing, characterized by, The current collector, the active material layer, and the prefabricated adapter tab are included, the current collector includes a blank foil area and a cover area, the active material layer is arranged above the cover area, and the prefabricated adapter tab is connected with the blank foil area; The blank foil area includes a die-cut area and a tab area; The prefabricated adapter tab includes a tab welding area and a tab extension area; One end of the tab welding area is welded with the tab area, and the other end of the tab welding area is connected with the tab extension area; The width of the prefabricated adapter tab is the same as the width of the tab area.

2. The pole piece structure according to claim 1, wherein The prefabricated adapter tab is a metal foil.

3. The pole piece structure according to claim 1, wherein The length of the blank foil area is 3mm-10mm.

4. The pole piece structure according to claim 1, wherein The tab welding area is arranged on the tab area, and the tab extension area extends from the tab area.

5. The pole piece structure according to claim 1, wherein The length of the tab welding area is 1mm-10mm.

6. The pole piece structure of claim 1, wherein, The thickness of the tab welding area is 8μm-20μm.

7. The pole piece structure according to claim 1, wherein The thickness of the tab extension area is 8μm-20μm.

8. The pole piece structure of claim 1, wherein, The length of the prefabricated adapter tab is 5mm-40mm.

9. The pole piece structure of claim 1, wherein, The length of the tab extension area is 5mm-40mm.

10. The pole piece structure of claim 1, wherein, The prefabricated adapter tab is arranged on one side or both sides of the tab area.

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