Method for producing a battery with a metallic housing and an electrical insulation layer covering the outside of the housing, and battery produced by the method

Abstract

A method is disclosed for producing a battery with a metallic housing and an electrical insulation layer covering the outside of the housing. The method includes: providing a metallic housing or housing part for a battery; corona treating the outside of the housing or of the housing part, with simultaneous extraction of the gases and particles which arise; and applying the electrical insulation layer onto the treated outside of the housing or housing part.

Claims

1. A method for producing a battery with a metallic housing and an electrical insulation layer covering the outside of the housing, the method comprising: (i) providing a metallic housing or housing part for a battery; (ii) corona treating an outside of the housing or housing part with simultaneous extraction of gases arising and particles, the particles including one or more of metal particles, metal swarf, and process substances related to working of the metallic housing or housing part; and (iii) applying an electrical insulation layer to the treated outside of the housing or housing part, the electrical insulation layer consisting of a varnish.

2. The method as claimed in claim 1, wherein the housing or housing part is aluminum or an aluminum alloy.

3. A battery, comprising: a metallic housing or housing part for the battery; and an electrical insulation layer configured to cover an outside of the housing or housing part, the electrical insulation layer consisting of a varnish, wherein the outside of the housing or housing part is corona treated with simultaneous extraction of gases arising and particles, the particles including one or more of metal particles, metal swarf, and process substances related to working of the metallic housing or housing part.

4. The battery as claimed in claim 3, wherein the battery is a lithium-ion battery.

5. The method as claimed in claim 1, wherein corona treating the outside of the housing or housing part increases a surface tension of the outside.

6. The method as claimed in claim 1, wherein corona treating the outside of the housing or housing part brings a surface tension of the outside to a uniform level.

7. The method as claimed in claim 1, wherein corona treating the outside of the housing or housing part increases a surface tension of the outside by 21%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the disclosure are explained in more detail on the basis of the description that follows and the drawings, in which:

(2) FIG. 1 shows a schematic representation of a corona treatment of a battery housing;

(3) FIG. 2 shows a schematic representation of the application of an electrically insulating varnish to a treated battery housing; and

(4) FIG. 3 shows a schematic representation of the corona treatment with simultaneous extraction of ozone and particles.

DETAILED DESCRIPTION

(5) FIG. 1 shows in a highly schematized way the method step of the corona treatment of the outside of a housing 10 of a lithium-ion battery. The corona discharge 12 is produced here by means of the corona device 14.

(6) In a test, the housing 10 was produced from a commercially available rolled aluminum sheet. The corona treatment then allowed the surface tension to be increased from 34 mN/m to 41 mN/m. The corona device 14 was in this case a commercially available handheld device, and the surface tensions were measured with what are known as test inks.

(7) After successful corona treatment, an electrical insulation layer was applied to the metallic housing 10. As represented in FIG. 2, this may take place for example by spraying on a varnish 16.

(8) Simultaneously with the corona treatment, an extraction of ozone and other gases arising during the treatment and any small metal particles 20 from the surface of the housing 10 may take place with the aid of an extraction device 18 (see FIG. 3).

(9) The quality of the adhesion of the insulation layer was assessed by peeling tests. The tested variant with an aluminum surface and an electrical insulating varnish showed greatly improved results with respect to adhesion and surface quality and had no coating defects. Since the tolerances of the electrical insulation coatings after corona treatment fluctuate within smaller tolerances than untreated surfaces, this makes it possible to dispense with insulating varnish.

(10) Especially inhomogeneity of the coating, such as coating defects or instances of thinning, can lead to considerable problems in high-voltage applications if the voltage punctures regions where the layer thickness of the insulation is too thin and irreparably damages parts of the battery pack.