This application is the U.S. National Stage of International Application No. PCT/EP2013/001728, filed Jun. 12, 2013, which designated the United States and has been published as International Publication No. WO 2014/040666 and which claims the priority of German Patent Application, Serial No. 102012018344.5, filed Sep. 15, 2012, pursuant to 35 U.S.C. 119(a)-(d).
The invention relates to a method for the production of a battery module having several single electrochemical cells.
In traction batteries for electric vehicles, batteries are increasingly used with single electrochemical cells which may involve e.g. lithium-ion cells. Such single cells may have a cylindrical cell can as casing, in which a cell coil is inserted.
DE 10 2009 001 592 A1 describes a battery module having single cells which are embedded in an open-pore porous solid body. The solid body may be a metal foam, with heat generated during operation of the single cell being dissipated via the metal foam.
DE 10 2009 025 579 discloses a battery module having single cells. A single cell has a current collector which contacts a connecting pin that is enclosed by a metal foam.
In addition, other methods are known to contact the positive poles and the negative poles of the single electrochemical cell, a copper plate, for example, can be used for that purpose. However, welds are produced hereby by a laser welding process, the process parameters of which need to be closely monitored. This method requires therefore a very precise process control for use in single electrochemical cells.
The invention is therefore based on the object to provide a method for the production of a battery module having several single electrochemical cells, which method has high process reliability and can be executed in a simple and inexpensive manner.
This object is attained in accordance with the invention provided by a method of the afore-described type with the following steps:
The invention is based on the recognition that it is possible to eliminate the need for a separate common negative pole or positive pole for the single cells by using the metal foam, which encloses the cell cans, as negative pole or positive pole.
Since in the method according to the invention, the empty cell cans are embedded in the metal foam, there is no risk of damage to the cell coils by the high temperatures encountered during the production of the metal foam. Single cells can only be thermally exposed to about 80° C.; however, much higher temperatures are encountered during the production of a metal foam, so that respective recesses had to be provided heretofore for insertion of the single cells. Instead, in the method according to the invention, empty cell cans are initially arranged and embedded in the metal foam, subsequently, once the metal foam has cooled, cell coils are inserted into the cell cans to thereby create the single cells.
In the method according to the invention, it is particularly preferred to use cell cans of an electrically conductive material which are directly enclosed by the metal foam. Examples for the electrically conductive material include steel, aluminum, copper, and alloys thereof. These materials exhibit good conductivity. A cell coil has two contacts (positive pole and negative pole), after insertion of the cell coil in a cell can, a contact, typically the negative pole, is automatically connected with the electrically conductive cell can and with the electrically conductive metal foam via the cell can. Accordingly, all cell coils and thus all single cells are electrically interconnected, when the cell coils are inserted in the cell cans, so that a common negative pole or a common positive pole is established for several or all single cells of a battery module.
According to a refinement of the invention, the cell cans are closed by a cover after the cell coils have been inserted. The respective other pole, normally the positive pole of the single cells, can be situated above the cover. The positive poles of the plurality of single cells can be interconnected by a plate of a conductive material or by a printed circuit board or the like having contacts.
In addition, the invention relates to a battery module having several single electrochemical cells embedded in a metal foam and having each a cell coil arranged in a cell can.
The battery module according to the invention is characterized in that the single cells have cell cans made of an electrically conductive material and being directly enclosed by the metal foam.
With respect to the metal foam of the battery module according to the invention, it is preferred that the metal foam is made of aluminum or an aluminum alloy. Such metal foams are characterized by a low density, while at the same time ensuring good heat conduction, so that heat generated during charging and discharging of single cells can be dissipated via the cell can and the metal foam.
According to a refinement of the invention, the metal foam can include at least one filler such as hollow glass beads, which may, optionally, be filled with a phase change material. The provision of a filler such as hollow glass beads results in a reduction in the density. When the hollow glass beads are filled with a phase change material, the heat storage capability of the metal foam is significantly increased. As an alternative, the phase change material can be incorporated directly into the voids of the metal foam.
Further embodiments of the invention are described in the subclaims.
An exemplary embodiment of the invention will now be explained with reference to the drawings. The drawings are schematic views and show:
As the metal foam 2 undergoes foaming, high temperatures are encountered which, however, do not lead to an impairment of the empty cell cans 1. After the foaming process, the cell cans 1 encased in foam are allowed to cool down, at least until a temperature for the cell coils drops below a critical temperature of 80° C. The further processing of the cell cans 1 encased in foam can also be realized after a cool down to room temperature.
Since both the cell cans 1 and the metal foam 2 are electrically conductive, electrical contacting is established automatically.
Number | Date | Country | Kind |
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10 2012 018 344 | Sep 2012 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2013/001728 | 6/12/2013 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2014/040666 | 3/20/2014 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4397919 | Ballard | Aug 1983 | A |
20090004556 | Al-Hallaj | Jan 2009 | A1 |
20130052506 | Gutsch | Feb 2013 | A1 |
Number | Date | Country |
---|---|---|
101859912 | Oct 2010 | CN |
102544622 | Jul 2012 | CN |
102790246 | Nov 2012 | CN |
600 28 409 | Jan 2007 | DE |
10 2009 001 592 | Sep 2010 | DE |
10 2009 025 579 | Dec 2010 | DE |
10-2009-025579 | Dec 2010 | DE |
1 104 050 | May 2001 | EP |
2011-150902 | Aug 2011 | JP |
Entry |
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Rohatgi et al, The Synthesis, Compressive Properties, and Applications of Metal Matrix Syntactic Foams, 36-42 JOM vol. 63, No. 2 (2011). |
International Search Report issued by the European Patent Office in International Application PCT/EP2013/001728. |
Chinese Search Report issued on Jun. 13, 2016 with respect to counterpart Chinese patent application 201380047707.1. |
Translation of Chinese Search Report issued on Jun. 13, 2016 with respect to counterpart Chinese patent application 201380047707.1. |
Number | Date | Country | |
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20150228956 A1 | Aug 2015 | US |