Collector Foil and Method for Producing a Collector Foil

Abstract

A collector foil includes a base material which has at least one coating region on one side or on either side, and an uncoated region of the base material has at least one stretching region which is designed to mechanically decouple the at least one coating region from the uncoated region.

Claims

1.-15. (canceled)

16. A collector foil comprising: a base material comprising at least one coating region on at least one side of the base material, wherein an uncoated region of the base material comprises at least one expanding region that is configured to mechanically decouple the at least one coating region from the uncoated region.

17. The collector foil according to claim 16, wherein the expanding region comprises at least one material aperture or at least one material weakening.

18. The collector foil according to claim 16, wherein: the base material in the expanding region has at least one slit or cut, and the at least one slit or cut is in a form of a straight line, a zigzag, an arrow or an arc.

19. The collector foil according to claim 16, wherein the expanding region has an expanded-metal-like structure.

20. The collector foil according to claim 16, wherein the expanding region is formed only in the uncoated region.

21. The collector foil according to claim 16, wherein the expanding region is in a form of an edge or strip which runs at least partially around a periphery of the at least one coating region.

22. The collector foil according to claim 16, wherein the base material in the uncoated region is not completely formed as an expanding region.

23. The collector foil according to claim 16, wherein: the base material extends in a sheet direction, the at least one coating region comprising a strip-like coating region, and expanding regions are formed in a transition from the strip-like coating region to the uncoated region.

24. The collector foil according to claim 16, wherein: the base material extends in a sheet direction, the at least one coating region comprises a plurality of coating regions arranged in the sheet direction, and expanding regions are arranged around a periphery of at least some of the coating regions.

25. A method for producing a collector foil, the method comprising: introducing an expanding region into at least a part of a base material of a collector foil, wherein the expanding region is configured to mechanically decouple a coating region of the base material from an uncoated region of the base material.

26. The method according to claim 25, wherein the expanding region is introduced into the base material before, during or after a coating of the base material.

27. The method according to claim 25, wherein the expanding region is introduced when calendering of the collector foil is being performed.

28. The method according to claim 27, further comprising: pre-lengthening the expanding region before the calendering of the collector foil is performed.

29. The method according to claim 27, further comprising: using at least one of one or more offset rollers, an expander roller, or profiled guiding rolls during processing of the collector foil.

30. The method according to claim 29, wherein the processing comprises the calendaring.

31. A battery cell comprising a collector foil according to claim 16.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 shows a plan view of part of a collector foil in a schematic illustration.

[0034] FIG. 2 shows two further configurations of collector foils.

[0035] FIG. 3 shows several details or views of a detail of collector foils for the purpose of illustrating different configurations of expanding regions.

[0036] FIG. 4 shows a schematic view of a roller and of a length-equalizing unit.

[0037] FIG. 5 shows various views of a detail of guiding rolls, as outlined in FIG. 4.

DETAILED DESCRIPTION OF THE DRAWINGS

[0038] FIG. 1 shows a plan view of a detail of a collector foil, comprising a base material 10 which extends in a longitudinal or sheet direction B. The base material 10 comprises an uncoated region 22 and a strip-like coating region 20, which is coated with the corresponding active material. The composition of this active material depends on whether the collector foil is for the anode or the cathode.

[0039] FIG. 2 shows two further typical shapes of collector foils 10 with correspondingly formed coating regions 20. In the left half of FIG. 2, the coating regions 20 are applied intermittently. Outlined in the right half of FIG. 2 is a configuration which has two strip-like coating regions 20 next to one another. A base material 10 of this type is cut, for example in the center. The reference sign A outlines views of a detail which are illustrated in an enlarged manner in FIG. 3. The expanding regions formed there can be seen in particular in FIG. 3.

[0040] FIG. 3 shows, in an example a), an expanding region 30 comprising a multiplicity of cuts 32 which run obliquely in relation to a sheet direction, cf. also FIG. 2. It can also be seen that, in the embodiment shown there, the expanding region 30 is formed exclusively in a transition region between the coating region 20 and the uncoated region 22. By contrast, in the variant shown at b), the expanding region 30 extends over the entire uncoated region 22, that is to say here as far as the edge of the base material 10, cf. also FIG. 2. The cuts 32 here are in the form of cuts running transversely to the sheet direction B or to the first direction R. Any functional regions, for example regions in which welding operations are carried out on the collector foil, advantageously do not have an expanding region. The variants shown under c), d) and e) show further possible embodiments of expanding regions, different patterns of cuts being shown.

[0041] FIG. 4 shows a very schematic illustration of a roller 42 comprising a center roll and/or a center roller portion 46 having a second diameter, and also external guiding rolls 44 having first diameters, the first diameters being larger than the second diameters. In particular, the two diameters are adapted to a geometry of the collector foil. In this case, the guiding rolls 44 bear against the uncoated regions 22 of the base material 10, whereas the center roll 46 bears against the coating region 20. In the present case, the view is selected such that a sheet direction B or a first direction R runs perpendicularly into the plane of the drawing. The reference sign D outlines an axis of rotation of the roller 42. Schematically illustrated in the right half of the image is a length-equalizing unit 40 comprising a multiplicity of rollers 42 of this type, which may be a constituent part of a calendering installation and assists the expanding process. The passage of a base material 10 through the length-equalizing unit 40 is illustrated schematically. Reference sign A denotes a view of a detail, variants to this effect being pointed out in FIG. 5.

[0042] FIG. 5 shows several possible configurations of guiding rolls 44, reference being made to FIG. 4 in respect of their position and/or function. It can be seen that the guiding rolls 44 may have different outer circumferential surfaces or profiles. The outer circumferential surface may, for example, be formed straight, inclined or oblique or else convex or generally round. This makes it possible to achieve an introduction of force into the uncoated region(s) of the foil.

List Of Reference Signs

[0043] 10 Base material, carrier foil [0044] 20 Coating region [0045] 22 Uncoated region [0046] 30 Expanding region [0047] 32 Cut, slit [0048] 40 Length-equalizing unit [0049] 42 Roller [0050] 44 Guiding roll [0051] 46 Center roller portion [0052] B Sheet direction [0053] D Axis of rotation [0054] A Detail