Producing electrodes for lead acid batteries

Abstract

A system for producing electrodes for lead-acid batteries is disclosed. An electrode that has been produced comprises at least one upper and/or one lower frame element as well as a lattice-shaped region that extends away from said upper or lower frame element and has a plurality of openings, the upper and/or lower frame element being of a greater thickness than the lattice-shaped region. Said system comprises the steps of: a) producing a profiled strip-shaped blank using a casting method in which the strip-shaped blank is formed, solely by means of said casting method, to have a greater thickness on one side in at least one of the regions which should eventually form the upper or lower frame element, than the thickness in regions which should eventually form the lattice-shaped region, and b) producing said lattice-shaped region with the openings in a subsequent expanded metal process.

Claims

1. A system for manufacturing electrodes for lead-acid batteries, wherein the electrodes produced with the system includes an upper frame element, a lower frame element, or the upper frame element and the lower frame element, a meshed region extending away from the upper frame element and/or the lower frame element, the meshed region having a plurality of openings, wherein the upper frame element and/or the lower frame element is of greater thickness than the meshed region, the system consisting essentially of: a continuous casting system which alone is to produce a continuous profiled strip blank having a non-profiled side and a profiled side, the non-profiled side being flat, the profiled side having a greater thickness along a longitudinal length in a first region than in a second region, the first region is to form the upper frame element or the lower frame element and the second region is to form the meshed region, wherein lead is supplied to an input side of the continuous casting system, the lead is to be melted with the continuous casting system, and the continuous profiled strip blank is dispensed by the continuous casting system from an output side; an expanded metal, press to receive the continuous profiled strip blank and designed to produce the meshed region having the openings by way of an expanded metal process to yield an electrode strip; and a cutter to receive the electrode strip from the expanded metal press and to cut out therefrom individual electrodes.

2. The system of claim 1, wherein the expanded metal press comprises: a cutting device to cut longitudinal slots in the second region; and a drawing device to pull the cut blank in opposite directions to expand the longitudinal slots.

3. The system of claim 2, wherein the expanded metal press further comprises a punching device to punch the first region to create contact tabs.

4. The system of claim 1, wherein the electrodes produced with the system includes the upper frame element and the lower frame element, wherein the profiled side has a greater thickness along the longitudinal length in a third region than in the second region, and wherein the first region is to form the upper frame element and the third region is to form the lower frame element.

5. The system of claim 1, wherein a first portion of the continuous profiled strip blank corresponds to a first electrode and a second portion of the continuous profiled strip blank corresponds to a second electrode.

6. The system of claim 1, wherein the continuous profiled strip blank is produced with the first region, the second region, a third region, a fourth region, and a fifth region extending in a longitudinal direction of the continuous profiled strip blank, wherein the continuous profiled strip blank is also produced with closed material areas, and wherein the profiled side has a greater thickness along a longitudinal length in the first, third, and fifth regions than in the second and fourth regions.

7. The system of claim 6, wherein the first region is to form the lower frame element of a first electrode, the second region is to form the meshed region of the first electrode, the fourth region is to form the meshed region of a second electrode, the fifth region is to form the lower frame element of the second electrode, and the third region is to form the upper frame element of the first electrode and the upper frame element of the second electrode.

Description

BRIEF DESCRIPTION OF THE 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.