Producing electrodes for lead-acid batteries

Abstract

A method for manufacturing electrodes for lead-acid batteries includes producing a profiled strip blank in a casting process, wherein the casting process alone is sufficient to cause the strip blank to be formed of greater thickness on one side in a region corresponding to the upper frame element or the lower frame element than in another region corresponding to the meshed region; and producing the meshed region with the openings in a subsequent expanded metal process. In addition, an electrode produced by the method has an upper frame element, or a lower frame element, or both, and a meshed region extending away from the upper frame element, or the lower frame element, or both and having a plurality of openings. The upper frame element, the lower frame element, or both, is of greater thickness than the meshed region.

Claims

1. A method for manufacturing electrodes for lead-acid batteries, wherein a produced electrode has an upper frame element, a lower frame element, and a meshed region extending away from the upper frame element and the lower frame element and comprising a plurality of openings, wherein the upper frame element and the lower frame element are of greater thickness than the meshed region, the method comprising the steps of: a) producing a profiled strip blank in a casting process, wherein the strip blank corresponds to a first electrode and a second electrode that are positioned transverse to one another along a longitudinal length of the strip blank, wherein the casting process alone is sufficient to: cause the strip blank to be formed of greater thickness along the entire longitudinal length on a profiled side of the strip blank in a region corresponding to the upper frame element or the lower frame element than in another region corresponding to the meshed region; and form a non-profiled flat side of the strip blank opposite the profiled side of the strip blank; and b) producing the meshed region with the openings in a subsequent expanded metal process in a first portion of the strip blank that corresponds to the first electrode and in a second portion of the strip blank that corresponds to the second electrode by first providing longitudinal slots in the strip blank to form a slotted strip blank and by drawing the slotted strip blank in a direction transverse to a longitudinal extension of the lower frame element of the first and second electrode such that the meshed regions of the first electrode and the second electrode are produced simultaneously; and wherein the casting process is a continuous casting process in which lead is supplied to an input side of a casting system, the lead is melted using the casting system, and the profiled strip blank is dispensed as a continuous profiled mold by the casting system.

2. The method according to claim 1, wherein the strip blank is produced with a first region, a second region, and a third region, the first region, the second region, and the third region each extending in the longitudinal direction of the strip blank, and wherein the strip blank is also produced with closed material areas without openings, the closed material areas being of lesser thickness compared to the first region, the second region, and the third region, and the closed material areas are respectively produced between the first region and the second region as well as between the second region and the third region.

3. The method according to claim 2, wherein contact tabs of the electrodes are produced out of the second region.

4. The method according to claim 1, wherein an electrode assembly having the first and second electrodes, which is wound into a coil, is produced from the strip blank in a continuous expanded metal process.

5. The method according to claim 4, wherein the non-profiled flat side of the electrode assembly faces inwardly during coiling.

6. The method according to claim 1, wherein the first electrode and second electrode are pasted with active material subsequent to the expanded metal process.

7. The method according to claim 6, wherein the first electrode and second electrode are initially stored prior to being pasted with the active material, and the pasting process is conducted after a storage period.

8. The method according to claim 7, wherein the first electrode and second electrode are stored in coil form.

9. The method according to claim 3, wherein the contact tabs are produced out of the second region by die cutting.

10. The method according to claim 4, wherein the first electrode and the second electrode are pasted with active material subsequent to the expanded metal process and before detaching from the strip shaped electrode assembly.

11. The method according to claim 1, wherein the casting process is performed by a casting machine that does not include an extrusion unit.

12. The method of claim 2, wherein the second region corresponds to the upper frame element of the first and second electrodes.

13. A method, comprising: producing a profiled strip blank in a casting process, wherein the strip blank corresponds to at least a first electrode and a second electrode that are positioned transverse to one another along a longitudinal length of the strip blank, wherein the casting process is a continuous casting process in which lead is supplied to an input side of a casting system, the lead is melted using the casting system, and the profiled blank is dispensed as a continuous profiled mold by the casting system, and wherein the casting process alone causes the strip blank to comprise: a profiled side of the strip blank comprising a first region, a second region, a third region, a fourth region, and a fifth region, wherein the first region, third region, and fifth region are each thicker along the entire longitudinal length on the profiled side of the strip blank than the second region and the fourth region; and a non-profiled flat side of the strip blank opposite the profiled side of the strip blank; producing a first meshed region and a second meshed region in an expanded metal process, wherein the first meshed region and the second meshed region each comprise a plurality of openings, wherein the first meshed region corresponds to the second region and a first electrode, wherein the second meshed region corresponds to the fourth region and a second electrode; forming a plurality of contact tabs in the third region of the profiled strip blank; and detaching individual contact tabs of the plurality of contact tabs from portions of the third region of the profiled strip blank to form the first electrode and the second electrode.

14. The method of claim 13, wherein the second region is positioned between the first region and the third region, wherein the fourth region is positioned between the third region and the fifth region.

15. The method of claim 13, wherein the first electrode comprises a first upper frame element and a first lower frame element, wherein the second electrode comprises a second upper frame element and a second lower frame element, wherein the first lower frame element corresponds to the first region, wherein the second lower frame element corresponds to the fifth region, wherein the first and second upper frame elements correspond to the third region.

16. The method of claim 15, wherein the third region corresponds to the first upper frame element, the second upper frame element, and the plurality of contact tabs.

17. The method of claim 13, wherein the first region, second region, third region, fourth region, and fifth region each extend in the same direction along the profiled strip blank.

18. The method of claim 13, wherein the plurality of contact tabs is formed by die cutting.

Description

DRAWINGS

(1) The following will reference the drawings in describing embodiments of the invention in greater detail.

(2) Shown are

(3) FIG. 1 the production of a strip-shaped blank,

(4) FIG. 2 an electrode,

(5) FIG. 3 a lead-acid battery, and

(6) FIG. 4 a system for manufacturing electrodes for lead-acid batteries.

(7) The figures use the same reference numerals for elements which correspond to one another.

DETAILED DESCRIPTION

(8) FIG. 1 shows a casting system 1 which produces a strip-shaped blank 2 for electrodes of lead-acid batteries by means of a continuous casting process. The casting system 1 is supplied with lead on the input side (not shown). The casting system 1 melts the lead and dispenses the strip blank 2 as a continuous profiled mold in the extruded form shown in FIG. 1 on the output side. The strip blank 2 can then be further processed as described below.

(9) The distinctiveness of the casting system 1 according to FIG. 1 is that the strip blank 2 can be produced with a profile on one side such that the blank 2 exhibits different thicknesses D across its width B. It can be seen from FIG. 1 that the blank 2 exiting the casting system 1 has a substantially flat, smooth upper side 8 and a profiled underside. The blank 2 comprises regions 3, 5, 7 of greater thickness D than the regions 4, 6 situated therebetween. The regions 3, 5, 7 of greater thickness D project above regions 4, 6 on the underside. On the right, FIG. 1 shows a section of the strip blank 2 turned 180 about its longitudinal axis to show the profiled underside more visibly, illustrating the one-sided profile structure of the strip blank 2 extending in longitudinal direction L.

(10) Depending on embodiment, it is also conceivable for only the middle region 5 to exhibit increased thickness D.

(11) The casting machine 1 is thereby configured wholly without an extrusion unit; i.e. it effects purely a casting process without an extruding step.

(12) As will be described below, the regions 4, 6 of lesser thickness will be trans-formed into the meshed region by an expanded metal process, the upper and the lower frame element as well as part of the electrode contact tabs will be produced from the regions 3, 5, 7 of greater thickness.

(13) FIG. 2 shows a top plan view of an electrode 14 subsequent the expanded metal process in FIG. 2a. To illustrate the relationship to the strip blank 2, the electrode 14 is depicted with additional electrodes which are only partially reproduced at lower contrast or by dotted lines.

(14) As can be recognized, the electrode 14 comprises an upper frame element 10 with a contact tab 11 formed thereon, a lower frame element 9 and a meshed region 12 extending between the upper and the lower frame element 9, 10. To illustrate the relationship to the strip blank 2 according to FIG. 1, the corresponding reference numerals for the regions of the blank 2 from FIG. 1 are additionally reproduced.

(15) The arrows shown in FIG. 2a respectively pointing away from the upper frame element 10 and the lower frame element 9 indicate the direction of the drawing force to act on the electrodes 14 in the expanded metal process.

(16) Individual electrodes 14 are detached from the electrode strip exiting after the expanded metal process by individual electrodes being cut out, as represented by the triangles 13 in FIG. 2a. Correspondingly, the contact tabs 11 are also detached from the upper frame element 10 of the respective oppositely situated electrode. The interstices 15 between the contact tabs 11 are produced by die cutting.

(17) FIG. 2 shows a side view of the produced electrode 14 on the right in FIG. 2b, from which the profiled structure is recognizable.

(18) FIG. 3 shows a lead-acid battery 30 comprising a plurality of electrodes 14 of the type described above. The lead-acid battery 30 comprises a cover part 33 having external terminals 31, 32. The external terminals 31, 32 are respectively connected to positive/negative electrodes via the respective electrode connector 35, 36. For example, the connection of a negative electrode connector 35 to a contact tab 11 of an electrode 14 which in the present case is used as a negative electrode is recognizable. The negative electrode connector 35 is connected to the further negative electrodes and to terminal 31. Analogously, the positive electrode connector 36 is connected to the contact tabs of the positive electrodes 39 and to the other terminal 32.

(19) The lead-acid battery 30 comprises a lower housing part 34 in which the electrodes 14, 39 are disposed. The electrodes 14, 39 are provided with a pasty active material 37. The electrodes 14, 39 together with the pasty active material 37 are additionally respectively enveloped by a separator material 38.

(20) FIG. 4 shows an example of a system for manufacturing electrodes for lead-acid batteries of the type described above. The casting system 1 is again recognizable as the first system component. The above-described strip blank 2 exits from the casting system 1. The strip blank 2 is fed to an expanded metal press 40 which represents the second system component. The expanded metal press 40 first comprises a cutting unit which for example has cutting blades attached to a rotary roller. The cutting blades cut short longitudinal slots, e.g. just a few millimeters in length, into the strip-shaped blank in regions 4, 6. After the strip blank has passed through the cutting unit, it is fed to a drawing device of the expanded metal press 40. The drawing process is realized in the drawing device by the frame elements 9, 10 being pulled apart in opposite directions as shown in FIG. 1 by the arrows of FIG. 2a.

(21) Lastly, the blank is fed to a punching section in the expanded metal press 40 in which the clear regions 15 between the contact tabs 11 are punched out. The electrode strip 41 ultimately exiting the machine 40, as depicted in FIG. 4, corresponds to the electrode strip as described with reference to FIG. 2.