Electrode foil arrangement and battery

Abstract

Electrode foil arrangement, comprising: a cathode foil (100); an anode foil (200) arranged opposite the cathode foil (100), wherein the longitudinal direction of the anode foil (200) coincides with the longitudinal direction of the cathode foil (100) and the width of the anode foil (200) is not less than the width of the cathode foil (100); the anode foil (200) is provided with a rectangular exposed foil area (300) and a first long edge of the exposed foil area (300) located on the anode foil (200) overlaps a long edge of the anode foil (200), and / or the cathode foil (100) is provided with a rectangular exposed foil area (300) and a first long edge of the exposed foil area (300) located on the cathode foil (100) overlaps a long edge of the cathode foil (100); and a protective film (400) arranged between the cathode film (100) and the anode film (200) opposite the exposed film area (300), wherein the protective film (400) is rectangular, a first long edge of the protective film (400) overlaps the long edge of the cathode film (100), and two wide edges of the protective film (400) and a second long edge of the protective film (400) are outside a projection of the exposed film area (300) onto the cathode film (100).

Description

TECHNICAL AREA

[0001] The present disclosure relates to the field of batteries, in particular an electrode foil arrangement and a battery. BACKGROUND

[0002] In battery manufacturing, tabs must be joined to electrode foils. Using the example of joining an anode foil to a tab, a rectangular exposed foil area is created on the anode foil by laser cleaning or other methods. One of the wide edges of the exposed foil area overlaps a long edge of the anode foil. Then, a portion of the straight, strip-shaped tab is welded to the exposed foil area, and a rectangular protective film is positioned in an area on the cathode foil opposite the exposed foil area. The size of the protective film is larger than the projection of the exposed foil area onto the cathode foil. One of the wide edges of the protective film overlaps a long edge of the cathode foil, and the remaining edges of the protective film lie outside the exposed foil area.However, after the protective film has been placed on the cathode film, the cathode active material layer cannot function in the area covered by the protective film; that is, the above arrangement of the exposed film area and the protective film significantly impairs the energy density of the battery. SUMMARY

[0003] The present disclosure aims to solve at least one of the technical problems of the prior art. Therefore, the present disclosure provides an electrode foil arrangement which can reduce the area of ​​the cathode foil covered by the protective film, thereby improving the energy density of the battery.

[0004] The present disclosure further provides a battery which has the electrode foil arrangement described above.

[0005] According to a first aspect of the present disclosure, an embodiment provides an electrode foil arrangement comprising a cathode foil, an anode foil, and a protective foil. The anode foil is arranged opposite the cathode foil. The longitudinal direction of the anode foil corresponds to the longitudinal direction of the cathode foil. The width of the anode foil is not less than the width of the cathode foil. The anode foil is provided with a rectangular exposed foil area, and a first long edge of the exposed foil area located on the anode foil overlaps a long edge of the anode foil, and / or the cathode foil is provided with a rectangular exposed foil area, and a first long edge of the exposed foil area located on the cathode foil overlaps a long edge of the cathode foil.The protective film is located between the cathode foil and the anode foil and faces the exposed foil area. The protective film is rectangular. One long edge of the protective film overlaps the long edge of the cathode foil. Two wide edges of the protective film and a second long edge of the protective film lie outside the projection of the exposed foil area onto the cathode foil.

[0006] The electrode foil arrangement according to the embodiment of the first aspect of this disclosure has at least the following advantages. The first long edge of the exposed foil area overlaps with the long edge of the anode foil or the cathode foil, the first long edge of the protective foil overlaps with the long edge of the cathode foil, and the two broad edges and the second long edge of the protective foil are located outside the area of ​​projection of the exposed foil area. Compared to methods known from the prior art, the section of the protective foil that overlaps the long edge of the cathode foil changes from one of the broad edges of the protective foil to the first long side of the protective foil, so that the area of ​​the cathode active material layer of the cathode foil covered by the protective foil can be reduced, and the cathode foil can comprise a larger functional cathode active material layer.In this way, the energy density of the battery can be improved when the electrode foil arrangement is used in a battery.

[0007] According to some embodiments of the present disclosure, the two broad edges of the protective film and the second long edge of the protective film are equidistant from the projection of the exposed film area onto the cathode film.

[0008] According to some embodiments of the present disclosure, the protective film is connected to the cathode film.

[0009] According to some embodiments of the present disclosure, the width of the anode foil is greater than the width of the cathode foil.

[0010] According to some embodiments of the present disclosure, the electrode foil arrangement further comprises a tab, wherein the tab is provided with a rectangular crossbar section, the crossbar section is connected to the exposed foil area and a longitudinal direction of the crossbar section coincides with a longitudinal direction of the exposed foil area.

[0011] According to some embodiments of the present disclosure, the length of the exposed film area is greater than the length of the crossbar section, and the width of the exposed film area is greater than the width of the crossbar section.

[0012] According to some embodiments of the present disclosure, the tab is provided with a rectangular vertical web section, wherein the longitudinal direction of the vertical web section coincides with the width direction of the transverse web section and one end of the vertical web section is connected to the transverse web section.

[0013] According to some embodiments of the present disclosure, the vertical web section is provided with a flap adhesive or bonding agent, and the flap adhesive is located outside the exposed film area.

[0014] According to some embodiments of the present disclosure, the exposed foil area is arranged on the cathode foil and a cathode active material layer is arranged in a region of the cathode foil outside the exposed foil area; and the exposed foil area is arranged on the anode foil, and an anode active material layer is arranged in a region of the anode foil outside the exposed foil area.

[0015] According to some embodiments of the present disclosure, a width dimension of the exposed foil area is defined as A, a length dimension of the exposed foil area is defined as B, and 1.1A ≤ B ≤ 5.5A.

[0016] According to some embodiments of the present disclosure, the thickness of the vertical web section is defined as E, the thickness of the transverse web section is defined as F, and 0.4E ≤ F ≤ E.

[0017] According to some embodiments of the present disclosure, the tab is further provided with a projecting section, wherein the projecting section and the vertical web section are arranged on two opposite sides of the transverse web section, one end of the projecting section is connected to the transverse web section, a distance between the other end of the projecting section and the transverse web section is defined as G and G ≤ 4 mm.

[0018] According to a second aspect of the present disclosure, one embodiment provides a battery comprising the electrode foil arrangement described above.

[0019] The battery according to the embodiment of the second aspect of the present disclosure has at least the following advantages. By using the electrode foil arrangement described above, the cathode foil comprises a larger layer of cathode active material that can function, thus improving the energy density of the battery.

[0020] Further aspects and benefits of the present revelation are set forth in the following description, some of which will be evident from the following description or can be learned from the practice of the present revelation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above-mentioned and / or further aspects and advantages of the present disclosure will become apparent and understandable from the description of the embodiments in conjunction with the accompanying drawings, in which: Fig. 1 a schematic diagram of an electrode foil arrangement in which an anode foil is provided with an exposed foil area in the technology known from the prior art; Fig. 2 is a schematic diagram of an electrode foil arrangement in which an anode foil is provided with an exposed foil area according to an embodiment of the present disclosure; Fig. 3 a schematic diagram of an electrode foil arrangement in which a cathode foil is provided with an exposed foil area in the technology known from the prior art; Fig. 4 is a schematic diagram of an electrode foil arrangement in which a cathode foil is provided with an exposed foil area according to an embodiment of the present disclosure; Fig. 5 a schematic diagram of a first embodiment of a tab in an electrode foil arrangement according to an embodiment of the present disclosure; Fig. Figure 6 is a schematic diagram of a second embodiment of a tab in an electrode foil arrangement according to an embodiment of the present disclosure; Fig. Figure 7 is a schematic diagram of a third embodiment of a tab in an electrode foil arrangement according to an embodiment of the present disclosure; and Fig. Figure 8 is a schematic diagram of a tab with a projecting section in an electrode foil arrangement according to an embodiment of the present disclosure.

[0022] Reference symbol: Cathode foil 100; Anode foil 200; exposed foil area 300; Protective film 400; Tab 500, transverse web section 510, vertical web section 520, projecting section 530; Tab adhesive 600. DETAILED DESCRIPTION

[0023] Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings, in which identical or similar reference numerals refer to identical or similar elements or elements with identical or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and serve only for illustration and are not to be understood as limiting the present disclosure.

[0024] In describing the present disclosure, it should be noted that, for the purposes of describing orientations, the orientations or positional relationships indicated by terms such as "on" and "under" are based on the orientations or positional relationships shown in the accompanying drawings and are used solely to facilitate the description of the present application and to simplify the description, rather than indicating or implying that the device or element in question must have a particular orientation or be designed and operated in a particular orientation. Therefore, such terms should not be interpreted as limiting the present disclosure.

[0025] In the description of this disclosure, “more” means two or more. When described herein, terms such as “first” and “second” are used solely to distinguish technical features and are not intended to indicate or imply any relative significance, nor to imply the number of technical features disclosed, nor to imply any ranking of the technical features disclosed.

[0026] In the description of the present disclosure, terms such as “provide / arrange”, “install / assemble” and “connect”, unless expressly defined otherwise, are to be understood in a broader sense, and a person skilled in the art can appropriately determine the specific meanings of the above-mentioned terms in the present disclosure on the basis of the specific content of the technical scheme.

[0027] Improving the energy density of lithium batteries has always been a key focus of lithium battery research. Modifying the material system typically leads to changes or even a deterioration in the system's performance. However, improving energy density by modifying the battery structure while leaving the chemical system unchanged reduces the likelihood of performance alterations or deterioration.

[0028] In the battery production process, it is necessary to connect tabs to electrode foils. Using the example of connecting an anode foil to a tab, a rectangular area of ​​exposed foil is created on the anode foil by laser cleaning or other means. One of the wide edges of the exposed foil area overlaps a long edge of the anode foil. Then, a portion of the straight, strip-shaped tab is welded to the exposed foil area, and a rectangular protective film is positioned in an area on the cathode foil opposite the exposed foil area. The size of the protective film is larger than the projection of the exposed foil area onto the cathode foil. One of the wide edges of the protective film overlaps a long edge of the cathode foil, and the remaining edges of the protective film lie outside the exposed foil area.However, once the protective film is applied to the cathode foil, the cathode active material layer can no longer function in the area covered by the protective film. The arrangement of the exposed foil area and the protective film described above has a significant impact on the battery's energy density.

[0029] With reference to Fig. 1 to Fig. Figure 7 describes an embodiment of the present disclosure comprising an electrode foil arrangement comprising a cathode foil 100, an anode foil 200, and a protective foil 400. The anode foil 200 is arranged opposite the cathode foil 100. The longitudinal direction of the anode foil 200 corresponds to the longitudinal direction of the cathode foil 100. The width of the anode foil 200 is not less than the width of the cathode foil 100. The anode foil 200 is provided with a rectangular exposed foil area 300, and a first long edge of the exposed foil area 300 located on the anode foil 200 overlaps with a long edge of the anode foil 200, or the cathode foil 100 is provided with a rectangular exposed foil area 300, and a first long edge of the exposed foil area 300 located on the cathode foil 100 overlaps with a long edge of the cathode foil 100.The protective film 400 is located between the cathode film 100 and the anode film 200 and is situated opposite the exposed film area 300. The protective film 400 is rectangular. A first long edge of the protective film 400 overlaps the long edge of the cathode film 100. Two wide edges of the protective film 400 and a second long edge of the protective film 400 are located outside a projection of the exposed film area 300 onto the cathode film 100.

[0030] The first long edge of the exposed foil area 300 overlaps with the long edge of the anode foil 200 or the cathode foil 100, the first long edge of the protective foil 400 overlaps with the long edge of the cathode foil 100, and the two broad edges and the second long edge of the protective foil 400 are located outside the area of ​​projection of the exposed foil area 300. Compared to prior art methods, the section of the protective foil 400 that overlaps with the long edge of the cathode foil 100 changes from one of the broad edges of the protective foil 400 to its first long side, so that the area of ​​the cathode active material layer of the cathode foil 100 covered by the protective foil 400 can be reduced and the cathode foil 100 can comprise more of the cathode active material layer that is functional.When the electrode foil arrangement is applied to a battery, the energy density of the battery can be improved.

[0031] In particular, the exposed foil area 300 can be arranged on both the cathode foil 100 and the anode foil 200 to further improve the energy density of a battery when the electrode foil arrangement described above is applied to the battery.

[0032] In particular, the exposed foil area 300 is located near the long edge of the cathode foil 100 or the anode foil 200. A first edge of the exposed foil area 300 is closer to the edge of the cathode foil 100 or the anode foil 200 than a second edge of the exposed foil area 300, and the first and second edges of the exposed foil area 300 have the same length. In particular, the first edge of the protective foil 400 is closer to the projection of the exposed foil area 300 than the second edge of the protective foil 400, and the first and second edges of the protective foil 400 have the same length. The projection of the protective foil 400 onto the cathode foil 100 does not extend beyond the area of ​​the cathode foil 100.

[0033] In one embodiment, the two wide edges and the second long edge of the protective film 400 are equidistant from the projection of the exposed film area 300 onto the cathode film 100. To completely block the influence of the exposed film area 300 on the adjacent cathode film 100 or anode film 200, the protective film 400 is typically configured to extend beyond the exposed film area 300 by a certain distance. The above structure allows the protective film 400 to be processed according to the size of the exposed film area 300 by calculation. Processing is relatively simple, and the exposed film area 300 is well protected, thus improving safety performance.The first edge of the protective film 400 overlaps the edge of the cathode film 100 and the edge of the projection of the exposed film area 300 onto the cathode film 100, and the second edge of the protective film 400 is outside the area of ​​the projection of the exposed film area 300.

[0034] In one embodiment, the protective film 400 is connected to the cathode film 100, which simplifies processing and saves material for the protective film 400. It is conceivable that in some cases the protective film 400 could be connected to the anode film 200, as long as the protective film 400 can cover the cathode film 100.

[0035] In particular, the protective film 400 is an insulating adhesive tape that is glued onto and covers the cathode foil 100. It is conceivable that in some cases the protective film 400 could also be other insulating films that are bonded to and cover the cathode foil 100 by adhesive or other means.

[0036] After the cathode foil 100 has been covered with the protective foil 400, the cathode active material layer in the covered area can no longer function, which affects the energy density of the battery.

[0037] In one embodiment, the width of the anode foil 200 is greater than the width of the cathode foil 100, which improves the safety performance. It is also conceivable that the width of the anode foil 200 could be equal to the width of the cathode foil 100.

[0038] In one embodiment, the electrode foil arrangement further comprises a tab 500, wherein the tab 500 is provided with a rectangular transverse web section 510. The transverse web section 510 is connected to the exposed foil area 300, and one longitudinal direction of the transverse web section 510 is the same as one longitudinal direction of the exposed foil area 300. Compared to a conventional tab, the provision of the transverse web section 510 allows the tab 500 to be connected to the exposed foil area 300 with the same contact area as the conventional tab, while maintaining the same connection strength. In particular, the tab 500 is welded to the exposed foil area 300 by welding. The conventional tab is straight and strip-shaped and is partially welded to the exposed foil area 300.After the crossbar section 510 is provided, the corresponding tab 500 should also be provided with a crossbar section 510 which corresponds to the shape of the exposed foil area 300 in order to maintain the bond strength between the tab and the electrode foil, since the exposed foil areas 300 of the tab 500 and the conventional tab are the same size.

[0039] In one embodiment, the length of the exposed film area 300 is greater than the length of the crossbar section 510, and the width of the exposed film area 300 is greater than the width of the crossbar section 510. The size of the crossbar section 510 is smaller than the size of the exposed film area 300, so that the crossbar section 510 of the tab 500 fits completely onto the exposed film area 300.

[0040] In one embodiment, the tab 500 is provided with a rectangular vertical web section 520, wherein the longitudinal direction of the vertical web section 520 coincides with the lateral direction of the transverse web section 510, and one end of the vertical web section 520 is connected to the transverse web section 510. The provision of the vertical web section 520 facilitates the current flow through the vertical web section 520 of the tab 500.

[0041] In one embodiment, the vertical beam section 520 is provided with a flap adhesive 600, and the flap adhesive 600 is located outside the exposed film area 300. The provision of the flap adhesive or adhesive 600 can reduce the risk of liquid leakage during the use of a bag cell.

[0042] In one embodiment, an exposed foil region 300 is arranged on the cathode foil 100, and a cathode active material layer is arranged in a region of the cathode foil 100 outside the exposed foil region 300; and an exposed foil region 300 is arranged on the anode foil 200, and an anode active material layer is arranged in a region of the anode foil 200 outside the exposed foil region 300. The arrangement of the exposed foil region 300 on both the cathode foil 100 and the anode foil 200 further improves the energy density of a battery when the electrode foil arrangement described above is used in the battery.In particular, the exposed foil area 300 on the cathode foil 100 can be formed by removing the cathode active material layer on the cathode foil 100 by laser cleaning or directly during the application of the cathode active material layer to a cathode current collector. Similarly, the exposed foil area 300 on the anode foil 200 can be formed by removing the anode active material layer on the anode foil 200 by laser cleaning or directly during the application of the anode active material layer to an anode current collector.

[0043] The following examples illustrate how the approaches described above reduce the impact on energy density. Maintaining the existing weld strength and current-carrying capacity, the size of the exposed foil area 300 remains the same as before. A width dimension of the rectangular exposed foil area 300 is defined as A, a length dimension of the rectangular exposed foil area 300 is defined as B, and B > A. An edge of the protective foil 400 overlaps an edge of the cathode foil 100. The dimension by which the remaining edges of the protective foil 400 extend beyond the exposed foil area 300 is defined as C. If the width of the anode foil 200 is not less than the width of the cathode foil 100, the dimension by which the long edge of the anode foil 200 extends beyond the long edge of the cathode foil 100 is defined as D.

[0044] In a case where the exposed foil area 300 is arranged on the anode foil 200: In the prior art technology, a broad edge of the exposed foil area 300 overlaps the long edge of the anode foil 200, and in this case, the exposed foil area 300 has a projection onto the cathode foil 100. Therefore, the area of ​​the protective foil 400, which is connected to the cathode foil 100 and opposite the exposed foil area 300, is: S1 = (B - D + C) × (A + 2C).

[0045] One edge of the improved exposed foil area 300 overlaps the edge of the anode foil 200, and in this case the exposed foil area 300 has a projection onto the cathode foil 100. Therefore, the area of ​​the protective foil 400 that is connected to the cathode foil 100 and opposite the exposed foil area 300 is: S2 = (B + 2C) × (A - D + C).

[0046] S1 - S2 = (B - D + C) × (A + 2C) - (B + 2C) × (A - D + C) = (B - A) × (C + D). Because B > A, B - A > 0. Since C + D must be greater than 0, S1 - S2 > 0, i.e., S1 > S2. Therefore, implementing the technical scheme of the present disclosure can reduce the area of ​​the cathode foil 100 blocked by the protective foil 400, thus reducing the influence of the protective foil 400 on the energy density of the electrode foil assembly and improving the energy density of the electrode foil assembly and the battery.

[0047] For a case in which the exposed foil area 300 is arranged on the cathode foil 100: In the prior art technology, a broad edge of the exposed foil area 300 overlaps the long edge of the cathode foil 100, and in this case, the projection of the exposed foil area 300 onto the cathode foil 100 is the exposed foil area 300 itself. Therefore, the area of ​​the protective foil 400, which is connected to the cathode foil 100 and opposite the exposed foil area 300, is: S3 = (B + C) × (A + 2C).

[0048] One edge of the improved exposed foil area 300 overlaps with the edge of the cathode foil 100, and in this case, the projection of the exposed foil area 300 onto the cathode foil 100 is the exposed foil area 300 itself. Therefore, the area of ​​the protective foil 400, which is connected to the cathode foil 100 and opposite the exposed foil area 300, is: S4 = (B + 2C) × (A + C).

[0049] S3 - S4 = (B + C) × (A + 2C) - (B + 2C) × (A + C) = (B - A) × C. Since B > A, B - A > 0. Since C > 0, S3 - S4 must be greater than 0, i.e., S3 > S4. Therefore, implementing the technical scheme can reduce the area of ​​the cathode foil 100 blocked by the protective foil 400, thus reducing the influence of the protective foil 400 on the energy density of the electrode foil assembly and improving the energy density of both the electrode foil assembly and the battery.

[0050] In one embodiment, the width dimension of the exposed foil area 300 is defined as A, the length dimension of the exposed foil area 300 is defined as B, and 1.1A ≤ B ≤ 5.5A. When the exposed foil area 300 described above is arranged on the cathode foil 100 or the anode foil 200, the size range described above is applied in both cases, resulting in improved energy density of the battery. It is understood that the length dimension B of the exposed foil area 300 can be, for example, 2A, 3A, 4A, or 5A, or other values ​​within the range, and can be determined by those skilled in the art according to the actual requirements.

[0051] In one embodiment, the thickness of the vertical bar section 520 is defined as E, the thickness of the crossbar section 510 is defined as F, and 0.4E ≤ F ≤ E. Since the crossbar section 510 is connected to the exposed foil area 300 of the electrode foil by stacking, the relatively small thickness of the crossbar section 510 prevents the stack of the crossbar section 510 and the electrode foil from having excessive thickness, thereby reducing the thickness-related occupancy of the electrode foil assembly and the battery, which is advantageous for improving the energy density of the electrode foil assembly and the battery. The vertical bar section 520 has a relatively large thickness, so that the vertical bar section 520 can maintain sufficient current-carrying capacity.

[0052] With reference to Fig.In some embodiments, the tab 500 is further provided with a projecting section 530. The projecting section 530 and the vertical web section 520 are arranged on two opposite sides of the transverse web section 510. One end of the projecting section 530 is connected to the transverse web section 510. The distance between the other end of the projecting section 530 and the transverse web section 510 is defined as G, where G ≤ 4 mm. Due to tolerances in the manufacturing process, the tab 500 includes the projecting section 530 described above. If the projection dimension G of the projecting section 530 is too large, too much of the exposed film area 300 is occupied. Therefore, in practical applications, it is necessary to limit the projection dimension G of the projecting section 530 to no more than 4 mm to ensure good performance of the tab 500.It is understood that the distance G between the other end of the preceding section 530 and the transverse web section 510 may be, for example, 1 mm, 2 mm, or 3 mm, or other values ​​within this range, and may be determined by those skilled in the art according to the actual requirements. It is understood that the preceding section 530 may not be present during the manufacture of the tab 500, in which case G = 0 mm.

[0053] In particular, one edge of the tab 500 can be right-angled or rounded, preferably rounded.

[0054] Furthermore, the vertical web section 520 and the transverse web section 510 are arranged such that the tab 500 can be T-shaped, L-shaped, or the like, or arranged in any desired configuration to facilitate current flow. Preferably, the tab 500 is T-shaped to achieve good current conductivity.

[0055] In contrast to a conventional scheme, in the technical scheme of the present disclosure the exposed foil area 300 is realigned by rotation, so that the weld strength and electrical conductivity of an existing tab 500 are maintained, while improving the energy density of the electrode foil arrangement and the battery without affecting the electrochemical performance of the battery.

[0056] The present disclosure further discloses a battery that uses the electrode foil arrangement described above. By using the electrode foil arrangement described above, the cathode foil comprises 100 more functional cathode active material layers, thus improving the energy density of the battery.

[0057] In the description of this disclosure, the terms “an embodiment”, “some embodiments”, “exemplary embodiments”, “an example”, “specific example”, or “some examples”, etc., mean that certain features, structures, materials, or properties described in connection with the embodiment or example are included in at least one embodiment or example of this disclosure. In this description, exemplary expressions of the foregoing terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials, or properties may be combined in one or more embodiments in any suitable manner.

[0058] Although the embodiments of the present disclosure have been shown and described, a person skilled in the art will recognize that various changes, modifications, substitutions and variations can be made to the embodiments without deviating from the principles and objectives of the present disclosure, and that the scope of protection of the present disclosure is defined by the attached claims and their equivalents.

Claims

[1] Electrode foil arrangement comprising: a cathode foil (100); an anode foil (200) arranged opposite the cathode foil (100), wherein the longitudinal direction of the anode foil (200) coincides with the longitudinal direction of the cathode foil (100) and the width of the anode foil (200) is not less than the width of the cathode foil (100); the anode foil (200) is provided with a rectangular exposed foil area (300) and a first long edge of the exposed foil area (300) located on the anode foil (200) overlaps a long edge of the anode foil (200), and / or the cathode foil (100) is provided with a rectangular exposed foil area (300) and a first long edge of the exposed foil area (300) located on the cathode foil (100) overlaps a long edge of the cathode foil (100); and a protective film (400) arranged between the cathode film (100) and the anode film (200) opposite the exposed film area (300), wherein the protective film (400) is rectangular, a first long edge of the protective film (400) overlaps the long edge of the cathode film (100), and two wide edges of the protective film (400) and a second long edge of the protective film (400) are outside a projection of the exposed film area (300) onto the cathode film (100). [2] Electrode foil arrangement according to claim 1, wherein the two wide edges of the protective foil (400) and the second long edge of the protective foil (400) are equidistant from the projection of the exposed foil area (300) onto the cathode foil (100). [3] Electrode foil arrangement according to claim 1, wherein the protective foil (400) is connected to the cathode foil (100). [4] Electrode foil arrangement according to claim 1, wherein the width of the anode foil (200) is greater than the width of the cathode foil (100). [5] Electrode foil arrangement according to claim 1, which further comprises a tab (500), wherein the tab (500) is provided with a rectangular crossbar section (510), the crossbar section (510) is connected to the exposed foil area (300) and the longitudinal direction of the crossbar section (510) coincides with the longitudinal direction of the exposed foil area (300). [6] Electrode foil arrangement according to claim 5, wherein the length of the exposed foil area (300) is greater than the length of the crossbar section (510) and the width of the exposed foil area (300) is greater than the width of the crossbar section (510). [7] Electrode foil arrangement according to claim 5, wherein the tab (500) is provided with a rectangular vertical web section (520), wherein the longitudinal direction of the vertical web section (520) coincides with the width direction of the transverse web section (510) and wherein one end of the vertical web section (520) is connected to the transverse web section (510). [8] Electrode foil arrangement according to claim 7, wherein the vertical web section (520) is provided with a tab adhesive (600) and the tab adhesive (600) is located outside the exposed foil area (300). [9] Electrode foil arrangement according to claim 1, wherein the exposed foil area (300) is arranged on the cathode foil (100) and a cathode active material layer is arranged in a region of the cathode foil (100) outside the exposed foil area (300); and the exposed foil area (300) is arranged on the anode foil (200) and an anode active material layer is arranged in a region of the anode foil (200) outside the exposed foil area (300). [10] Electrode foil arrangement according to claim 1, wherein a width dimension of the exposed foil area (300) is defined as A, a length dimension of the exposed foil area (300) is defined as B and 1, 1A ≤ B ≤ 5,5A applies. [11] Electrode foil arrangement according to claim 7, wherein a thickness of the vertical web section (520) is defined as E, a thickness of the transverse web section (510) is defined as F and 0.4E ≤ F ≤ E applies. [12] Electrode foil arrangement according to claim 7, wherein the tab (500) is further provided with a projecting section (530), the projecting section (530) and the vertical rod section (520) are arranged on two opposite sides of the crossbar section (510), one end of the projecting section (530) is connected to the crossbar section (510), a distance between the other end of the projecting section (530) and the crossbar section (510) is defined as G and G ≤ 4 mm. [13] Battery comprising the electrode foil arrangement according to any one of claims 1 to 12.

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