Producing a rechargeable battery

Abstract

A rechargeable battery is produced by welding a metal foil to a contact element to make electrical contact with an electrode of the rechargeable battery. An edge region of the metal foil is brought into contact with a first surface of the contact element and welded to the contact element by applying a laser beam to a second surface of the contact element. The second surface being averted from (opposite to) the first surface of the contact element. The metal foil and further planar constituents of the rechargeable battery are wound to provide the rechargeable battery with an at least essentially cylindrical design. The contact element-is oriented at right angles to the metal foil.

Claims

1. A method for producing a rechargeable battery, comprising: coupling an edge region of a metal foil with a first surface of contact element of a contact-connection of an electrode of the rechargeable battery; and welding the contact element to the metal foil by applying a laser beam to a second, opposing, surface of the contact element using a feed motion of the laser beam that is superimposed by an oscillating motion.

2. The method as claimed in claim 1, wherein the metal foil and further planar constituents of the rechargeable battery are wound to provide the rechargeable battery with an at least essentially cylindrical design, wherein the metal foil is brought into contact with, and welded to the first surface of the contact element, which is oriented at right angles to the metal foil.

3. The method as claimed in claim 1, wherein a region of the metal foil is bent prior to winding.

4. The method as claimed in claim 3, wherein the metal foil is bent through 180° in a region of the bend.

5. The method as claimed in claim 1, wherein a region of the metal foil which is to be bonded to the contact element protrudes, in relation to other laminar constituents of the rechargeable battery in a direction of the contact element by at least 1 mm and by no more than 8 mm.

6. The method as claimed in claim 1, wherein the metal foil is welded to a projecting region of the first surface of the contact element.

7. The method as claimed in claim 1, wherein a pole element is welded to the contact element.

8. The method as claimed in claim 7, wherein the pole element includes a sealing surface and wherein welded joints for connection of the metal foil to the contact element are at least partially overlapped by the sealing surface of the pole element.

9. The method as claimed in claim 7, wherein the pole element is welded to the contact element using the same laser.

10. The method as claimed in claim 7, wherein the metal foil is one of: copper or a copper alloy.

11. The method as claimed in claim 1, wherein a single-mode fiber optic laser having a wavelength of 1,070 nm, is employed.

12. The method as claimed in claim 11, wherein the laser is operated as a continuous-wave laser having a power of at least 100 W.

13. The method as claimed in claim 11, wherein the laser is focused using a focusing lens having a focal length of at least 10 mm.

14. The method as claimed in claim 11, wherein the laser has a beam with a focal diameter of at least 1 μm.

15. The method as claimed in claim 14, wherein a rate of feed of the laser beam along a welded joint produced is at least 10 mm/s.

16. The method as claimed in claim 15, wherein the oscillating motion has a frequency of at least 100 Hz and an amplitude of at least 0.02 mm.

17. The method as claimed in claim 1, wherein the oscillating motion has an amplitude of at least 0.1 mm.

18. The method as claimed in claim 1, wherein the oscillating motion has an amplitude of at least 0.5 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The system described herein is set forth in greater detail hereinafter with reference to the several figures of the drawings, noted as follows:

(2) FIG. 1 shows a schematic perspective representation of part of a rechargeable battery, produced according to the system described herein.

(3) FIG. 2 shows a schematic representation of a contact element, in an overhead view, according to the system described herein.

(4) FIG. 3 shows a detailed representation of a weld of the metal foil to the contact element, according to the system described herein.

(5) FIG. 4 shows a schematic representation of a trajectory of the laser during welding according to the system described herein.

(6) FIG. 5 shows a side view of a pole element according to the system described herein.

(7) FIG. 6 shows a sectional representation of the pole element according to the system described herein.

(8) FIG. 7 shows an overhead view of the pole element according to the system described herein.

(9) FIG. 8 shows a perspective representation of the pole element according to the system described herein.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

(10) A rechargeable battery 1 according to the system described herein includes a contact element 2, which is welded to a metal foil 3. For the production of the rechargeable battery 1 represented in FIG. 1, FIG. 3 shows that an edge region of the metal foil 3 is brought into contact with a first surface 4 of the contact element 2. By the application of a laser beam 6 to a second surface 5 of the contact element 2, which is averted from the first surface 4 of the contact element 2, the contact element 2 is welded to the metal foil 3.

(11) In an embodiment described herein, the metal foil 3 is wound with further planar constituents of the rechargeable battery, specifically the electrodes, to constitute a spiral winding. This produces a rechargeable battery of cylindrical design. In the example represented, the metal foil 3 is arranged at right angles to the first surface 4 of the contact element 2.

(12) According to an advantageous form of an embodiment, the contact element 2, in the example represented, includes an opening 7, and possibly a plurality of openings 7.

(13) As represented in FIG. 3, the first surface 4 of the contact element 2, in the example represented, includes a plurality of projecting regions 8. The projecting regions 8 are advantageously configured as beadings 9. The metal foil 3 and the projecting regions 8, in an advantageous manner, are mutually oriented such that the metal foil 3 and the projecting regions 8 intersect.

(14) In the example represented, the contact element 2 has a thickness of 0.3 mm. The projecting regions 8 project by 0.4 mm in relation to the first surface 4.

(15) In the example represented, the metal foil 3 includes a bent region 10. The metal foil 3, in the region of the bend 11, engages with the projecting region 9 of the first surface 4 of the contact element 2. The thickness of the metal foil 3 is preferably 0.01 mm.

(16) In the interests of clarity, a section line 12 corresponding to FIG. 3 is shown in FIG. 2.

(17) In an embodiments of the method according to the system described herein, the metal foil 4 and the contact element 2 are welded in each case using a single-mode fiber laser with a wavelength of 1,070 nm. A trajectory 13 of the laser beam represented schematically in FIG. 4 is produced by the superimposition of a feed motion 14 and a circular oscillating motion 15.

(18) 1.sup.st Embodiment

(19) According to a first embodiment, the laser power of the continuously operated laser is 300 W. The speed of the feed motion 14 is 100 mm/s. The frequency of the oscillating motion 15 is 1,000 Hz. The amplitude 16 of the oscillating motion 15 is 0.2 mm. The material of the contact element 2 and the metal foil 3 is copper. The focusing lens employed has a focal length of 160 mm, and the focal diameter is 14 μm.

(20) 2.sup.nd Embodiment

(21) According to a second embodiment, the laser power of the continuously operated laser is 300 W. The speed of the feed motion 14 is 120 mm/s. The frequency of the oscillating motion 15 is 1,000 Hz. The amplitude 16 of the oscillating motion 15 is 0.3 mm. The material of the contact element 2 and the metal foil 3 is aluminum. The focusing lens employed has a focal length of 160 mm, and the focal diameter is 14 μm.

(22) 3.sup.rd Embodiment

(23) According to a third embodiment, the laser power of the continuously operated laser is 400 W. The speed of the feed motion 14 is 110 mm/s. The frequency of the oscillating motion 15 is 1,000 Hz. The amplitude 16 of the oscillating motion 15 is 0.3 mm. The material of the contact element 2 and the metal foil 3 is copper. The focusing lens employed has a focal length of 330 mm, and the focal diameter is 29 μm.

(24) 4.sup.th Embodiment

(25) According to a fourth exemplary embodiment, the laser power of the continuously operated laser is 300 W. The speed of the feed motion 14 is 110 mm/s. The frequency of the oscillating motion 15 is 1,000 Hz. The amplitude 16 of the oscillating motion 15 is 0.3 mm. The material of the contact element 2 and the metal foil 3 is aluminum. The focusing lens employed has a focal length of 330 mm, and the focal diameter is 29 μm.

(26) In an advantageous manner, the laser, in the context of the method according to the system described herein, can also be employed for the welding of a pole element 17 to the contact element 2. In the example represented, the pole element 17 includes a sealing surface 18. The function thereof is to provide a pole of the rechargeable battery 1 which, in the example represented, appropriately includes a thread 19. As can specifically be seen from a comparison of FIG. 1 and FIG. 2, the pole element 17, at its sealing surface 18, partially overlaps the beadings 9, along which the welded joints between the contact element 2 and the metal foil 3 are executed.

(27) The welding of the pole element 17 can be executed, for example, in the region of a connection region 20 of the pole element. In the example represented, the connection region 20 surrounds the sealing surface 18.

(28) Appropriately, for the welding of the pole element 17 to the contact element 2, the laser power is increased, for example, to 800 W. In the embodiment shown, the focusing lens employed has a focal length of 330 mm. The feed motion 14 of the laser beam, in the welding of the pole element, is also superimposed by an oscillating motion 15. The frequency of the circular oscillating motion is, for example, 800 Hz, and the amplitude is 0.2 mm. The rate of feed can be, for example, 100 mm/s. In the example represented, the pole element 17, in an advantageous manner, is constituted of the same material as the contact element 2, preferably of copper or aluminum.