Battery pole piece, laminated battery core package, laminated battery structure and power utilization device

Abstract

The utility model relates to the technical field of batteries, and discloses a battery pole piece, a laminated battery core package, a laminated battery structure and an electric device. The battery pole piece comprises a foil and coatings, the width of the foil extends in the X direction, the length of the foil extends in the Y direction, the X direction is perpendicular to the Y direction, the foil is provided with a notch, an empty foil area and a dressing area, the notch and the empty foil area are located at the edge of the foil, and the coatings are attached to the two side faces of the dressing area in the thickness direction respectively. The side, in the X direction, of the empty foil area and the side, in the Y direction, of the empty foil area are connected with the dressing area. According to the utility model, one side of the empty foil area along the X direction and one side of the empty foil area along the Y direction are respectively connected with the dressing area of the foil, and when the empty foil area is connected with the tab, the welding strength of the tab and the empty foil area can be improved, and meanwhile, the dressing area of the battery pole piece can be increased, and the battery capacity can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery pole piece, a laminated battery core pack, a laminated battery structure and an electrical device. Background Art

[0002] The conventional manufacturing process of existing laminated batteries is to cut the coated positive and negative electrodes into specific sizes, then stack the positive electrode, separator, negative electrode, and separator in sequence to form a "sandwich" structure, and then weld the tabs. Figure 7 and Figure 8 As shown, the area for welding the tabs consists of a small portion of third hollow foil 12' reserved for the head of the positive electrode tab 1', and a small portion of fourth hollow foil 22' reserved for the head of the negative electrode tab 2'. Due to the inherently small size of ultra-small batteries, the welding area is limited by the size of the hollow foil area, making welding strength difficult to guarantee. Furthermore, the tensile strength of the foil itself is also affected. This is particularly true for curved and special-shaped batteries that require reshaping, which are susceptible to internal stress and breakage. Furthermore, the weld area of ​​this laminated structure protrudes outside the membrane area, preventing the effective use of the space between welds to increase capacity. Utility Model Content

[0003] The purpose of the embodiments of the present utility model is to provide a battery pole piece, a laminated battery core pack, a laminated battery structure and an electrical device, which can improve the connection strength between the empty foil area and the dressing area and the dressing area of ​​the dressing area, thereby increasing the battery capacity.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] In a first aspect, a battery electrode sheet is provided, comprising a foil and a coating, wherein the width of the foil extends along the X direction, the length of the foil extends along the Y direction, the X direction being perpendicular to the Y direction, the foil having a notch, an empty foil area, and a dressing area, the notch and the empty foil area being located at the edge of the foil, the coating being attached to both side surfaces of the dressing area along its thickness direction, one side of the dressing area along the X direction overlapping with one side of the empty foil area along the X direction, and one side of the dressing area along the Y direction overlapping with one side of the empty foil area along the Y direction.

[0006] As a further solution of the battery electrode, the notch and the empty foil area are respectively located at two adjacent corners of the foil material, and the coating extends between the notch and the empty foil area.

[0007] As a further solution of the battery electrode sheet, the notch is consistent in size with the empty foil area, and the notch and the empty foil area are symmetrical relative to the center line of the foil along the X direction.

[0008] In a second aspect, a laminated battery core pack is provided, comprising a plurality of battery electrodes and a plurality of diaphragms, wherein some of the battery electrodes are positive electrodes and some of the battery electrodes are negative electrodes, and the positive electrodes and the negative electrodes are stacked alternately in the thickness direction, and the diaphragm is located between the adjacent positive electrodes and the negative electrodes, and the positive electrode sheets comprise a first foil and a first coating, wherein the first foil has a first notch, a first empty foil area and a first dressing area for applying the first coating, and the negative electrode sheets comprise a second foil and a second coating, wherein the second foil has a second notch, a second empty foil area and a second dressing area for applying the second coating, and the first notch is opposite to the second empty foil area, and the second notch is opposite to the first empty foil area.

[0009] As a further solution of the laminated battery core pack, the first notch and the first empty foil area are respectively located at two adjacent corners of the positive electrode sheet, and the first coating extends between the first notch and the first empty foil area; the second notch and the second empty foil area are respectively located at two adjacent corners of the negative electrode sheet, and the second coating extends between the second notch and the second empty foil area.

[0010] As a further solution of the laminated battery core pack, the width of the first foil and the second foil extends along the X direction, the length of the first foil and the second foil extends along the Y direction, the first notch and the first empty foil area are symmetrical with respect to the center line of the first foil along the X direction, the second notch and the second empty foil area are symmetrical with respect to the center line of the second foil along the X direction, and the X direction is perpendicular to the Y direction.

[0011] As a further solution of the laminated battery core pack, the first notch and the second notch are respectively rectangular structures.

[0012] According to a third aspect, a laminated battery structure is provided, comprising the laminated battery core pack, and further comprising a first metal strip, a first tab glue, a second metal strip and a second tab glue, wherein the first metal strip has a first section and a second section along its length, the first section is connected to all the first empty foil areas, and the first tab glue is arranged in the second section of the first metal strip; the second metal strip has a third section and a fourth section along its length, the third section is connected to all the second empty foil areas, and the second tab glue is arranged in the second section of the second metal strip.

[0013] As a further solution of the laminated battery structure, it also includes an aluminum-plastic film shell, the laminated battery core pack is accommodated in the aluminum-plastic film shell, the first section extends into the aluminum-plastic film shell and is spot-welded to the first empty foil area, the third section extends into the aluminum-plastic film shell and is spot-welded to the second empty foil area, the second section and the fourth section are located outside the aluminum-plastic film shell, the first pole ear glue is hot-melt-connected to the second section and the aluminum-plastic film shell, respectively, and the second pole ear glue is hot-melt-connected to the fourth section and the aluminum-plastic film shell, respectively.

[0014] As a further solution of the laminated battery structure, the laminated battery structure is an arc-shaped structure.

[0015] In a fourth aspect, an electrical device is provided, which is equipped with the laminated battery structure described above.

[0016] Beneficial effects: In the present invention, one side of the empty foil area along the X direction and one side along the Y direction are respectively connected to the dressing area of ​​the foil, which can improve the connection strength between the empty foil area and the dressing area. When the battery is shaped, the empty foil area is not easy to break; when the empty foil area is connected to the tab, the welding strength between the tab and the empty foil area can be improved, and at the same time, the dressing area of ​​the battery electrode can be increased, thereby increasing the battery capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the area division of the first foil material of the positive electrode sheet described in Example 1 of the present invention.

[0019] Figure 2 This is a schematic diagram of the positive electrode sheet described in Example 1 of the present utility model.

[0020] Figure 3 This is a schematic diagram of the area division of the second foil material of the negative electrode plate described in Example 1 of the present invention.

[0021] Figure 4 This is a schematic diagram of the negative electrode sheet described in Example 1 of the present invention.

[0022] Figure 5 This is a schematic diagram of the exploded view of the laminated battery core pack described in Example 2 of the present utility model.

[0023] Figure 6 This is a schematic diagram of the laminated battery structure described in Example 3 of the present utility model.

[0024] Figure 7 This is a schematic diagram of the positive electrode sheet described in the comparative example of the present invention.

[0025] Figure 8This is a schematic diagram of the negative electrode sheet described in the comparative example of the present invention.

[0026] Figures 1 to 6 middle:

[0027] 100, positive electrode sheet; 101, first area; 102, second area; 110, first foil; 111, first notch; 112, first empty foil area; 113, first dressing area; 120, first coating;

[0028] 200, negative electrode sheet; 201, third region; 202, fourth region; 210, second foil; 211, second notch; 212, second empty foil region; 213, second dressing region; 220, second coating;

[0029] 300, diaphragm;

[0030] 410, first metal strip; 420, first tab glue;

[0031] 510, second metal strip; 520, second tab glue;

[0032] Figures 7 and 8 middle;

[0033] 1', positive electrode; 11', third coating; 12', third empty foil area; 13', third notch;

[0034] 2', negative electrode sheet; 21', fourth coating layer; 22', fourth empty foil area; 23', fourth notch. DETAILED DESCRIPTION

[0035] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0036] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0037] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0038] In the description of this embodiment, the terms "upper," "lower," "left," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and the like are used solely for descriptive purposes and do not have any special meaning.

[0039] Example 1

[0040] This embodiment provides a battery electrode sheet, including a foil and a coating. The width of the foil extends along the X direction, and the length of the foil extends along the Y direction, where the X direction is perpendicular to the Y direction. The foil has a notch, a hollow foil area, and a dressing area. The notch and the hollow foil area are located at the edge of the foil. The coating is attached to both sides of the dressing area along its thickness direction. The hollow foil area is connected to the dressing area on one side along the X direction and on one side along the Y direction.

[0041] The battery electrode is a positive electrode 100 or a negative electrode 200 .

[0042] Taking the positive electrode sheet 100 as an example, Figure 1 and Figure 2 As shown, the positive electrode sheet 100 includes a first foil 110 and a first coating 120. The length of the first foil 110 extends along the Y direction, and the X direction is perpendicular to the Y direction. The first foil 110 has a first notch 111, a first empty foil area 112 and a first dressing area 113. The first notch 111 and the first empty foil area 112 are located at the edge of the first foil 110. The first coating 120 is attached to both sides of the first dressing area 113 along the thickness direction thereof. One side of the first empty foil area 112 along the X direction and one side along the Y direction are respectively connected to the first dressing area 113.

[0043] Taking the negative electrode sheet 200 as an example, Figure 3 and Figure 4As shown, the negative electrode sheet 200 includes a second foil 210 and a second coating 220. The length of the second foil 210 extends along the Y direction, and the X direction is perpendicular to the Y direction. The second foil 210 has a second notch 211, a second empty foil area 212, and a second dressing area 213. The second notch 211 and the second empty foil area 212 are located at the edge of the second foil 210. The second coating 220 is attached to both sides of the second dressing area 213 along the thickness direction thereof. The second empty foil area 212 is connected to the second dressing area 213 on one side along the X direction and on one side along the Y direction.

[0044] Furthermore, one side of the dressing area along the X direction overlaps with one side of the empty foil area along the X direction, and one side of the dressing area along the Y direction overlaps with one side of the empty foil area along the Y direction, and the foil material is an integrally formed structure, indicating that one side of the empty foil area along the X direction and one side along the Y direction are respectively integrally connected to the dressing area. When the empty foil area is connected to the tab, the welding strength between the tab and the empty foil area can be improved.

[0045] Taking the positive electrode sheet 100 as an example, one side of the first dressing area 113 along the X direction coincides with one side of the first empty foil area 112 along the X direction, and one side of the first dressing area 113 along the Y direction coincides with one side of the first empty foil area 112 along the Y direction. The first foil material 110 is an integrally formed structure, indicating that one side of the first empty foil area 112 along the X direction and one side along the Y direction are respectively integrally connected to the first dressing area 113. When the first empty foil area 112 is connected to the corresponding tab, the welding strength between the tab and the first empty foil area 112 can be improved. Taking the negative electrode sheet 200 as an example, one side of the second dressing area 213 along the X direction coincides with one side of the second empty foil area 212 along the X direction, and one side of the second dressing area 213 along the Y direction coincides with one side of the second empty foil area 212 along the Y direction. The second foil material 210 is an integrally formed structure, indicating that one side of the second empty foil area 212 along the X direction and one side along the Y direction are respectively integrally connected to the second dressing area 213. When the second empty foil area 212 is connected to the tab, the welding strength between the tab and the second empty foil area 212 can be improved.

[0046] When the battery needs to be shaped into an arc-shaped structure or other special-shaped structure, the first and second empty foil areas 112, 212 are less likely to break during the shaping process due to the high connection strength between the first empty foil area 112 and the first dressing area 113, and the high connection strength between the second empty foil area 212 and the second dressing area 213. The first coating 120 of the corresponding first dressing area 113 extends from one side of the first empty foil area 112 along the Y direction to one side of the first empty foil area 112 along the X direction, and the second coating 220 of the second dressing area 213 extends from one side of the second empty foil area 212 along the Y direction to one side of the second empty foil area 212 along the X direction. Compared with the prior art, this increases the dressing area on the first foil 110 and the second foil 210, further improving the battery capacity.

[0047] Furthermore, the notch and the empty foil area are located at two adjacent corners of the foil, and the coating extends between the notch and the empty foil area. For structures where the positive and negative electrode tabs are located on the same side of the battery, arranging the notch and the empty foil area at two adjacent corners of the foil can maximize the area of ​​the dressing area between the notch and the empty foil area, thereby greatly improving the weld strength between the empty foil area and the tab and reducing the phenomenon of the empty foil area breaking during battery shaping.

[0048] Taking the positive electrode sheet 100 as an example, the first notch 111 and the first empty foil area 112 are respectively located at two adjacent corners of the first foil 110, and the first coating 120 extends between the first notch 111 and the first empty foil area 112. For the negative electrode sheet 200, the second notch 211 and the second empty foil area 212 are respectively located at two adjacent corners of the second foil 210, and the second coating 220 extends between the second notch 211 and the second empty foil area 212.

[0049] Furthermore, the size of the notch is consistent with that of the empty foil area, and the notch and the empty foil area are symmetrical with respect to the center line of the foil along the X direction.

[0050] Specifically, the first notch 111 and the first empty foil area 112 are of the same size, and are symmetrical with respect to the centerline of the first foil material 110 along the X direction. The second notch 211 and the second empty foil area 212 are of the same size, and are symmetrical with respect to the centerline of the second foil material 210 along the X direction. In this embodiment, by designing the notch and the empty foil area of ​​the battery electrode sheets to be of the same size and symmetrical with respect to the centerline of the foil materials along the X direction, the first empty foil area 112 of the positive electrode sheet 100 can be directly opposite the second notch 211 of the negative electrode sheet 200, and the first notch 111 of the positive electrode sheet 100 can be directly opposite the second empty foil area 212 of the negative electrode sheet 200 during subsequent stacking.

[0051] Exemplarily, the first notch 111 , the first empty foil area 112 , the second notch 211 , and the second empty foil area 212 are all rectangular structures.

[0052] Example 2

[0053] like Figure 5As shown, this embodiment also provides a laminated battery core pack, comprising a plurality of battery electrodes as in any of the above embodiments and a plurality of separators 300, wherein some of the battery electrodes are positive electrode sheets 100, and some of the battery electrodes are negative electrode sheets 200, and along the thickness direction, the positive electrode sheets 100 and the negative electrode sheets 200 are alternately stacked, and the separator 300 is located between the adjacent positive electrode sheets 100 and the negative electrode sheets 200, and the positive electrode sheet 100 includes a first foil 110 and a first coating 120. 0, the first foil 110 has a first notch 111, a first empty foil area 112 and a first dressing area 113 for applying a first coating 120, the negative electrode plate 200 includes a second foil 210 and a second coating 220, the second foil 210 has a second notch 211, a second empty foil area 212 and a second dressing area 213 for applying the second coating 220, the first notch 111 is opposite to the second empty foil area 212, and the second notch 211 is opposite to the first empty foil area 112.

[0054] The number of positive electrode sheets 100 is the same as that of negative electrode sheets 200. The specific number is not limited and can be determined according to actual needs. Figure 5 For example, there is one positive electrode sheet 100 and one negative electrode sheet 200, and one separator 300. The separator 300 is located between the positive electrode sheet 100 and the negative electrode sheet 200. The shape of the separator 300 is consistent with the shape of the first dressing area 113 and the second dressing area 213, and it serves as an insulator. Specifically, the first hollow foil area 112 of the positive electrode sheet 100 is directly opposite to the second notch 211 of the negative electrode sheet 200, and the second hollow foil area 212 of the negative electrode sheet 200 is directly opposite to the first notch 111 of the positive electrode sheet 100.

[0055] Furthermore, the first notch 111 and the first empty foil area 112 are respectively located at two adjacent corners of the positive electrode sheet 100, and the first coating 120 extends between the first notch 111 and the first empty foil area 112; the second notch 211 and the second empty foil area 212 are respectively located at two adjacent corners of the negative electrode sheet 200, and the second coating 220 extends between the second notch 211 and the second empty foil area 212.

[0056] In this embodiment, since the first notch 111 and the first empty foil area 112 are respectively located at two adjacent corners of the positive electrode sheet 100, and the second notch 211 and the second empty foil area 212 are respectively located at two adjacent corners of the negative electrode sheet 200, the area of ​​the first dressing area 113 located between the first notch 111 and the first empty foil area 112 and the area of ​​the second dressing area 213 located between the second notch 211 and the second empty foil area 212 can be maximized, which can improve the tensile strength of the electrode tab welded in the empty foil area.

[0057] Exemplarily, the first foil 110 is a rectangular structure having a first notch 111, and the second foil 210 is a rectangular structure having a second notch 211. The widths of the first foil 110 and the second foil 120 extend along the X direction, and the lengths of the first foil 110 and the second foil 210 extend along the Y direction. The first notch 111 and the first empty foil area 112 are symmetrical relative to the center line of the first foil 110 along the X direction, and the second notch 211 and the second empty foil area 212 are symmetrical relative to the center line of the second foil 210 along the X direction, and the X direction is perpendicular to the Y direction.

[0058] In this embodiment, the size and position of the first notch 111 and the first empty foil area 112 are designed to be symmetrical relative to the center line of the first foil material 110 along the X direction, and the size and position of the second notch 211 and the second empty foil area 212 are designed to be symmetrical relative to the center line of the second foil material 210 along the X direction. This facilitates die-cutting and cleaning. Moreover, during stacking, the first empty foil area 112 can be completely aligned with the second notch 211, and the second empty foil area 212 can be completely aligned with the first notch 111, thereby improving foil utilization.

[0059] Since the electrode tab welded to the empty foil area is a long strip structure, adaptively, in this embodiment, the first notch 111 and the second notch 211 are respectively designed as rectangular structures, and correspondingly, the first empty foil area 112 and the second empty foil area 212 are also rectangular structures, which facilitates the welding and fixation of the electrode tab and the corresponding empty foil area.

[0060] Example 3

[0061] This embodiment also provides a laminated battery structure, such as Figure 6 As shown, it includes a laminated battery core pack, and also includes a first metal strip 410, a first tab glue 420, a second metal strip 510 and a second tab glue 520. The first metal strip 410 has a first section and a second section along its length direction, the first section is connected to all the first empty foil areas 112, and the first tab glue 420 is arranged in the second section of the first metal strip 410; the second metal strip 510 has a third section and a fourth section along its length direction, the third section is connected to all the second empty foil areas 212, and the second tab glue 520 is arranged in the second section of the second metal strip 510.

[0062] The first section is located on one side of all first hollow foil areas 112 along the thickness direction and is connected to all first hollow foil areas 112. The second section is connected to the first tab glue 420 and is adjacent to the first section. The third section is located on one side of all second hollow foil areas 212 along the thickness direction and is connected to all second hollow foil areas 212. The fourth section is connected to the second tab glue 520 and is adjacent to the third section. The first metal strip 410 is connected to the first hollow foil area 112, and the second metal strip 510 is connected to the second hollow foil area 212. Because the first and second hollow foil areas 112 and 212 are connected to the corresponding dressing areas along one side of the X and Y directions, respectively, the first and second metal strips 410 and 510 have excellent tensile strength, thereby improving the structural stability of the laminated battery structure.

[0063] The laminated battery structure of this embodiment also includes an aluminum-plastic film shell (not shown in the figure), and the laminated battery core pack is accommodated in the aluminum-plastic film shell. The first section extends into the aluminum-plastic film shell and is spot-welded to the first empty foil area 112, the third section extends into the aluminum-plastic film shell and is spot-welded to the second empty foil area 212, the second section and the fourth section are located outside the aluminum-plastic film shell, the first tab glue 420 is heat-melted to the second section and the aluminum-plastic film shell, and the second tab glue 520 is heat-melted to the fourth section and the aluminum-plastic film shell.

[0064] Specifically, the aluminum-plastic film shell wraps the laminated battery core pack to protect the laminated battery core pack. The first tab glue 420 is hot-melt connected to the first metal strip 410 and the aluminum-plastic film shell respectively, and the first metal strip 410 and the aluminum-plastic film shell are sealed. The second tab glue 520 is hot-melt connected to the second metal strip 510 and the aluminum-plastic film shell respectively, and the second metal strip 510 and the aluminum-plastic film shell are sealed.

[0065] For example, the laminated battery structure of this embodiment is an arc-shaped structure. After the laminated battery core pack is packaged in an aluminum-plastic film shell and the first and second tab adhesives 420 and 520 are heat-melted, the laminated battery structure can be shaped into an arc-shaped structure or other special-shaped structure. Because the first hollow foil area 112 welded to the first metal strip 410 is connected to the first dressing area 113 on one side along the X and Y directions, and the second hollow foil area 212 welded to the second metal strip 510 is connected to the second dressing area 213 on one side along the X and Y directions, the first and second hollow foil areas 112 and 212 are not easily broken when the laminated battery structure is shaped.

[0066] This embodiment also provides an electrical device equipped with the laminated battery structure of any of the above embodiments.

[0067] Example 4

[0068] The preparation method of the battery electrode of this embodiment is as follows:

[0069] Providing a foil material, coating active dressings on both sides of the foil material, and forming a coating after the active dressings are dried;

[0070] Dividing the foil material with the coating into a first area, a second area, and a dressing area, wherein the first area and the second area are respectively located at the edges of the foil material, and connecting one side of the first area along the X direction and one side along the Y direction to the dressing area respectively;

[0071] The first area is cleaned to remove the coating of the first area and form a hollow foil area, and the second area is cut to form a notch.

[0072] Among them, the cleaning process can be laser cleaning, and the cutting process can be die-cutting using laser. Laser cleaning and die-cutting are both conventional technical means in this field and will not be described in detail.

[0073] Take the preparation method of the positive electrode sheet 100 as an example, Figure 1 and Figure 2 As shown, a first foil material 110 is provided. The first foil material 110 is a rectangular aluminum foil with dimensions of length * width * thickness = 30mm * 12mm * 6μm. The rectangular area in the upper left corner is the first area 101, the rectangular area in the upper right corner is the second area 102, and the remaining area is the first dressing area 113. An active dressing such as lithium cobalt oxide is coated on both sides of the aluminum foil. After the active dressing dries, a first coating 120 is formed. The first coating 120 in the first area 101 on both sides of the aluminum foil is laser cleaned to form a first empty foil area 112 in the first area 101. The second area 102 is then die-cut using a laser to form a first notch 111 in the second area 102. Finally, the first coating 120 is attached only to both sides of the first dressing area 113, thereby producing the following. Figure 2 The positive electrode sheet 100 shown in FIG. The dimensions of the first empty foil area 112 and the first notch 111 of the positive electrode sheet 100 are both length*width=4mm*3mm.

[0074] Taking the preparation method of the negative electrode sheet 200 as an example, Figure 3 and Figure 4As shown, a second foil material 210 is provided. The second foil material 210 is a rectangular copper foil with dimensions of length * width * thickness = 30mm * 12mm * 10μm. The rectangular area in the upper left corner is the third area 201, the rectangular area in the upper right corner is the fourth area 202, and the remaining portion is the second dressing area 213. An active dressing such as graphite is coated on both sides of the copper foil. After the active dressing dries, a second coating 220 is formed. The second coating 220 in the third area 201 on both sides of the copper foil is laser cleaned to form a second empty foil area 212 in the third area 201. Then, the fourth area 202 is die-cut using a laser to form a second notch 211 in the fourth area 202. Finally, the first coating 120 is attached only to both sides of the second dressing area 213, thereby producing the following. Figure 4 The negative electrode plate 200 shown in FIG. The second empty foil area 212 and the second notch 211 of the negative electrode plate 200 both have a size of length*width=4mm*3mm.

[0075] In the above embodiments, when preparing the positive electrode sheet 100 or the negative electrode sheet 200, the corresponding active dressings are different. As for the composition and preparation method of the active dressing, they are conventional technical means in the field and will not be described in detail.

[0076] Comparative Example

[0077] The preparation method of the positive electrode sheet 1' of this comparative example is as follows:

[0078] like Figure 7 As shown, a third foil is provided. The third foil is a rectangular aluminum foil with dimensions of 30 mm x 12 mm x 6 μm. The rectangular area in the upper left corner is the first area, the rectangular area in the upper right corner is the second area, and the remaining area is the third dressing area. An active dressing such as lithium cobalt oxide is coated on both sides of the third foil. After drying, the active dressing forms a third coating 11'. The third coating 11' in the first area of ​​both sides of the aluminum foil is laser cleaned to form a third hollow foil area 12' in the first area. The second area is then die-cut using a laser to form a third notch 13' in the second area, thereby producing a positive electrode plate 1'. The third hollow foil area 12' of the positive electrode plate 1' has dimensions of 4 mm x 3 mm in length and width, and the third notch 13' has dimensions of 8 mm x 3 mm in length and width.

[0079] The preparation method of the negative electrode plate 2' of this comparative example is as follows:

[0080] like Figure 8As shown, a fourth foil is provided. The fourth foil is a rectangular copper foil with dimensions of length * width * thickness = 30mm * 12mm * 10μm. The rectangular area in the upper right corner is the first area, the rectangular area in the upper left corner is the second area, and the remaining area is the fourth dressing area. An active dressing such as graphite is coated on both sides of the copper foil. After the active dressing dries, a fourth coating 21' is formed. The fourth coating 21' in the first area of ​​both sides of the copper foil is laser cleaned to form a fourth hollow foil area 22' in the first area. The second area is then die-cut using a laser to form a fourth notch 23' in the second area, thereby producing a negative electrode sheet 2'. The fourth hollow foil area 22' of the negative electrode sheet 2' has dimensions of length * width = 4mm * 3mm, and the fourth notch 23' has dimensions of length * width = 8mm * 3mm.

[0081] Tensile strength test

[0082] Next, tensile tests were conducted after spot welding the tabs to copper and aluminum foils of varying widths. The width of the copper and aluminum foils was the sum of the width of the third region between the first and second regions and the width of the empty foil area in the first region.

[0083] Copper foil with a length of 30 mm, a thickness of 6 μm, and widths of 3 mm, 5 mm, 7 mm, and 9 mm was prepared, with three samples of each size. Aluminum foil with a length of 30 mm, a thickness of 10 μm, and widths of 3 mm, 5 mm, 7 mm, and 9 mm was prepared, with three samples of each size. Tabs measuring 25 mm long by 3 mm wide were spot welded to the upper left corner of the copper foil sample and the upper right corner of the aluminum foil sample, respectively. Tensile tests were performed using a tensile testing machine at a speed of 300 mm / min. The measured results were averaged. The test results are shown in Table 1.

[0084] Table 1. Tensile strength of tabs welded on foils of different widths

[0085]

[0086] It can be seen from Table 1 that the wider the foil welded to the tab, the greater the tensile strength between the tab and the foil.

[0087] Three positive electrode sheet samples and three negative electrode sheet samples were prepared according to the methods of Example 4 and Comparative Example 1, and a tab with a length * width = 25 mm * 3 mm was spot welded to the empty foil area of ​​each sample. A tensile test was performed using a tensile testing machine at a speed of 300 mm / min. The test results are shown in Table 2.

[0088] Table 2. Tensile strength test results of the tabs welded on the pole pieces of Example 4 and Comparative Example 1

[0089]

[0090] It can be seen from Table 2 that welding the tabs to the empty foil area of ​​the battery electrode sheet produced by the method of this embodiment can effectively improve the tensile strength between the tabs and the battery electrode sheet.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the various embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery pole piece, characterized in that: The invention comprises a foil and a coating, wherein the width of the foil extends along the X direction, the length of the foil extends along the Y direction, the X direction being perpendicular to the Y direction, the foil having a notch, an empty foil area, and a dressing area, the notch and the empty foil area being located at the edge of the foil, the coating being attached to both sides of the dressing area along the thickness direction, and the empty foil area being connected to the dressing area on one side along the X direction and on one side along the Y direction.

2. The battery electrode according to claim 1, characterized in that: The notch and the empty foil area are respectively located at two adjacent corners of the foil material, and the coating extends between the notch and the empty foil area.

3. The battery electrode according to claim 1, characterized in that: The size of the notch is consistent with that of the empty foil area, and the notch and the empty foil area are symmetrical with respect to the center line of the foil material along the X direction.

4. A laminated battery core pack, characterized in that: The battery cell comprises a plurality of battery electrodes as claimed in any one of claims 1 to 3 and a plurality of separators, wherein some of the battery electrodes are positive electrodes and some of the battery electrodes are negative electrodes, and the positive electrodes and the negative electrodes are stacked alternately in the thickness direction, and the separator is located between the adjacent positive electrodes and the negative electrodes, and the positive electrode electrode comprises a first foil and a first coating, the first foil having a first notch, a first empty foil area and a first dressing area for applying the first coating, and the negative electrode electrode comprises a second foil and a second coating, the second foil having a second notch, a second empty foil area and a second dressing area for applying the second coating, the first notch being opposite to the second empty foil area, and the second notch being opposite to the first empty foil area.

5. The laminated battery core pack according to claim 4, characterized in that: The first notch and the first empty foil area are respectively located at two adjacent corners of the positive electrode sheet, and the first coating extends between the first notch and the first empty foil area; the second notch and the second empty foil area are respectively located at two adjacent corners of the negative electrode sheet, and the second coating extends between the second notch and the second empty foil area.

6. The laminated battery core pack according to claim 4, characterized in that: The widths of the first foil and the second foil extend along the X direction, the lengths of the first foil and the second foil extend along the Y direction, the first notch and the first empty foil area are symmetrical relative to the center line of the first foil along the X direction, and the second notch and the second empty foil area are symmetrical relative to the center line of the second foil along the X direction, and the X direction is perpendicular to the Y direction.

7. The laminated battery core pack according to any one of claims 4 to 6, characterized in that: The first notch and the second notch are respectively rectangular structures.

8. A laminated battery structure, characterized in that: The laminated battery core pack comprises the laminated battery core pack according to any one of claims 4 to 7, further comprising a first metal strip, a first tab glue, a second metal strip and a second tab glue, wherein the first metal strip has a first section and a second section along its length direction, the first section is connected to all the first empty foil areas, and the first tab glue is arranged in the second section of the first metal strip; the second metal strip has a third section and a fourth section along its length direction, the third section is connected to all the second empty foil areas, and the second tab glue is arranged in the second section of the second metal strip.

9. The laminated battery structure according to claim 8, characterized in that: It also includes an aluminum-plastic film shell, the laminated battery core pack is accommodated in the aluminum-plastic film shell, the first section extends into the aluminum-plastic film shell and is spot-welded to the first empty foil area, the third section extends into the aluminum-plastic film shell and is spot-welded to the second empty foil area, the second section and the fourth section are located outside the aluminum-plastic film shell, the first tab glue is heat-melted to the second section and the aluminum-plastic film shell, and the second tab glue is heat-melted to the fourth section and the aluminum-plastic film shell.

10. The laminated battery structure according to claim 8 or 9, characterized in that: The laminated battery structure is an arc-shaped structure.

11. An electrical device, characterized in that: The laminated battery structure according to any one of claims 8 to 10 is installed.

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