Patent Application
20120301776
The present invention relates to a battery cell, which, in particular, is designed as a flat battery cell. Such battery cells comprise a packaging in which at least one electrical cell was inserted. An electrical cell can be a primary battery cell, i.e. a non-rechargeable battery cell. The battery cell may also be a secondary battery cell, i.e. a rechargeable battery cell. A conductor (electrical conductor) is electrically conductive connected to electrodes of the electric cell. Such battery cells are used, particularly, in electrically powered vehicles.
The state of the art is described based on
The objective of the present invention is to provide an improved battery cell.
The underlying objective of the invention is solved by a battery cell, in particular, by a flat battery cell, comprising at least one packaging for receiving at least one electric cell, at least one conductor, which has at least one base section and at least one contacting section, wherein the contacting section is bent relative to the base section.
The contacting section is preferably used to bring the conductor in electrical connection with an external component, in particular with a connecting element or with a connecting sleeve. In addition, a contacting section can also be brought in indirect or direct contact with a contacting section of an adjacent battery cell to establish an electrical connection between two battery cells. Therein, the base section of the conductor represents the area of the conductor by means of which the conductor protrudes through the packaging. By means of a bending between the base section and the contacting section, the contacting section can be brought into a favorable geometrical position for improved connectivity.
Preferably, the contacting section is bent relative to the base section in expect to a bending axis, wherein the bending axis is arranged parallel to a direction of the module of the battery cell. The direction of the module of a prismatic battery cell can be defined via the alignment directions of the longest outer edge of the battery cell. The direction of the module of a prismatic cell can also be defined by an axis that is vertical to one side surface area, wherein, as a reference surface area, preferably, the side surface area is used, through which the base section protrudes through the packaging. The direction of the module for a round battery cell may be defined by the longitudinal axis, relative to which the cylindrical outer surface area of the round battery cell extends in parallel. The direction of the module can also be defined by a vertical line through the section of the surface area of the packaging of the battery cell, which is protruded by the base section.
Since the contacting section is bent relative to the base section in respect to a bending axis, which extends in the direction of the module of the battery cell, a contacting surface area, which is arranged on the contacting section, is aligned in parallel to the direction of the module. A tool, which may be used to connect two contacting sections, may then be moved to the contacting section, in particular by a movement in the direction of the module, and thereby, has to travel only a short distance. A tool arm, which may carry the tool, may be designed having a short arm. Such a tool may be a welding gun. A tool arm may be the arm of a welding gun.
By means of such bending, the contacting section, which comprises the contacting surface area, may extend in the direction of an adjacent battery cell, which is arranged at a largest side surface area of the battery cell. In particular, when contacting sections of adjacent battery cells are directed towards each other, a contacting of the contacting section is simplified and may result, in particular, in material and weight reduction.
Preferably, the contacting section is bent relative to the base section in an approximately perpendiculary manner. The term “perpendicular” or “rectangular” is generally to be interpreted in a broad sense and comprises also, in particular, deviations from exactly 90° all the way to 15°. Preferably, the sum of the degree of bending for two adjoining contacting sections of adjacently arranged battery cells equals 180°. Thereby, it may be achieved that the contacting sections are aligned parallel to each other.
Preferably, a conductor has at least two contacting sections. The contacting sections may be designed to be identical.
Preferably, a conductor has, essentially, an L-shape, wherein, in particular, one arm is formed by the base section and one arm is formed by the contacting section. The arms are, in particular, formed in an elongated shape and are, preferably, arranged in a perpendicular manner to each other. The arms are, preferably, formed flat-shaped.
In another embodiment, the conductor may be designed in a U-shape, which is, preferably formed by the base section and contacting sections, which are arranged laterally thereon, on each side. The contacting sections are arranged, preferably, on opposite areas of the base section. Both contacting sections are bent relative to the base section, preferably, each in respect to a bending axis, wherein both bending axes are, preferably, arranged in parallel to each other.
Preferably, the contacting section extends away from the base section in a direction, which runs perpendicular to a largest surface side area of the battery cell. For prismatic battery cells or round cells, the largest surface side area may be the one, which has, the largest surface area in terms of modules.
In round cells, the direction of the module may be perpendicular to a base circle, which spans, preferably, a cylindrical boundary surface area of the battery cell. The direction of the module thereby extends, in parallel, in particular coaxial to the cylindrical surface area.
Preferably, a contacting section is arranged in parallel to the base section. This can be implemented, in particular, by multiple bendings in respect to, in particular, two bending axes of the conductor. The bending axes may be arranged in parallel to each other. The bending axes may be aligned perpendicular to the direction of the module. Preferably, the contacting section is arranged at a distance in respect to the base section. Between the base section and the contacting section, a connecting bridge may be provided. The base section and the contacting section may extend in the same direction, in respect to the connecting bridge. The bending between the connecting bridge and the base section may be implemented to be of the same direction as the bending between contacting section and connecting bridge. The conductor may, preferably, have a U-shape, wherein the outer arms of the U-shape may be formed by the base section and the contacting section. The base of the U-shape may be formed by the connecting bridge. The connecting bridge may be arranged perpendicular in respect to the base section and/or to the contacting section. Preferably, a contacting section is spaced away from the base section by at least a length, which at least corresponds to a distance of the base section to a side surface area of the battery cell, which runs in parallel to the base section. Thereby, the contacting section is shifted from the base section by at least such a distance, that the contacting section aligns with a side surface area of the battery cell, or, in particular extends beyond the side surface area. Thereby, the contacting section can easily be brought into contact, in particular, with contacting sections, of battery cells that are similarly designed and adjacently arranged, all this without the need of additional components, in particular, of space bridging connecting bridges. This allows, in total, to reduce the number of components and thus, the weight, as well as the total assembly effort.
A contacting section may, preferably, have a sawtooth structure. A sawtooth structure may provide the advantage, that several different connecting points are present, which are, in particular produced by welding joints. Furthermore, in particular, tension stresses on the battery cells, which may be noticeable, in particular, as shear stresses on the contacting section, are thereby at least partially directed into normal force components. Thereby, the durability of the connection of the contacting section will be increased. Moreover, the modules of a contacting area of a contacting section may be enlarged by using a sawtooth structure. In this respect, an enlarged contacting surface area can be provided for connecting adjacent battery cells.
Preferably, the base section has at least one through-hole. Means of traction may be guided through the through-holes, which allow a tensioning/fixing of the base sections and/or the battery cell with other components. Preferably, the base section has a first aligning means, in particular at least one, further particular two aligning-holes. The aligning means may serve to align other components, in particular insulating elements, relative to the conductor and/or the battery cell. The aligning means may also be used for an alignment of an assembly tool.
Preferably, at least one spacing element is arranged between the base section and the contacting section. The spacing element serves for maintaining a predetermined distance and/or for a predetermined alignment, in particular an angular alignment, between a base section and a contacting section.
A spacing element may therein transfer a force, which acts either on the base section or on the contacting section, to the respectively other of the two elements. The spacer may be made of an electrically insulating material. The spacer may be made of an electrically conductive material.
Preferably, a width of a spacing element corresponds to a length of a section of the bridge of the conductor. A section of the bridge of the conductor may be a connecting bridge between the base section and the contacting section. The spacing element may be arranged between the contacting section and the base section.
The underlying objective of the invention is further achieved by a battery assembly, comprising at least two of the aforementioned battery cells, wherein contacting sections of adjacent battery cells are electrically connected with each other, in particular directly connected with each other.
Side surface areas of adjacent battery cells may be directly adjacent to each other. A heat conductive plate may be arranged between the side surface areas of adjacent battery cells.
Preferably, contacting sections of adjacent battery cells are directly electrically connected with each other, in particular by means of welding, further particulary by ultrasonic welding. Ultrasonic welding allows simply and reliably to connect two contacting section.
Preferably, U-shaped conductors of adjacent battery cells together form a closed surface area, in particular a circularly closed circumferential surface area. Thereby, in particular, two contacting sections, respectively of a battery cell are always connected with a contacting section of an adjacent battery cell, hence in total with two contacting sections. By means of the closed surface area, in particular, a high area moment of inertia of the two conductors, which are connected with each other, is established. Said conductors therefore display high rigidity vis-à-vis externally applied forces.
Preferably, an insulating body is arranged between the base sections of adjacent battery cells, in particular between the base sections of conductors, and, in particular within a closed surface area. The insulation body may serve as a spacing element between the base sections of two adjacently arranged battery cells. Therein, the spacing element is, preferably, arranged such that it may absorb pressure forces, which are caused by attaching conductors to each other, so that the conductor sections are held in their respective position in the battery cell. This is, in particular, advantageous, when the conductors are pressed together by means of traction. By fixing the conductor in its position relative to the battery cell, mechanical stresses on the conductor are avoided, in particular, on the connection to the battery cell or in the area, in which the conductor protrudes through the packaging of the battery cell. The insulating body can further be used for insulating the conductors of adjacent battery cells. This is advantageous, in particular, when the insulating body is arranged between two conductors, which are meant to not interfere with each other, by means of an electrically conductive connection. In case the insulation body is arranged between two electrically connectable conductors, the insulation material may also be made of electrically conductive material. In this case, the insulation body serves, in particular, as a mechanical spacing element, without acting as an electrical insulator.
In one battery assembly, similar insulating bodies may be used both as mechanical spacing elements, as well as electrical insulating elements. This leads to a reduction in the number of parts.
Preferably, the insulating body has a second through-hole. Preferably, a means of traction, which may press together the conductors and the insulation bodies, may be guided through the second through-hole. The second through-holes of the insulating bodies may have the same diameter as the first through-holes of the conductors.
Preferably, an insulating body has second aligning means, in particular in form of at least one aligning protrusion, in particular two aligning protrusions. Thereby, a first aligning means of battery cells, in particular of conductors of battery cells, may be brought in engagement with a second aligning means of the insulating bodies. In particular, one or several, in particular two, aligning protrusions of one or several insulation bodies may engage in one or several, in particular in two, aligning-holes of the battery cells, in particular, of the conductor.
Preferably, an anchor rod is guided through through-holes. The through-holes may be arranged in the insulating body and/or in the battery cell, in particular, in the conductors of the battery cell. This allows the pressing together of the aforementioned components.
The objective of the invention is further achieved by a method of producing an aforementioned battery assembly, comprising the following steps: contacting a side surface area of a battery cell with a side surface area of an adjacent battery cell, connecting a contacting section of a battery cell with a contacting section of an adjacent battery cell, in particular by material engagement. Preferably, the connection of the contacting section is established by joining by material engagement, in particular by welding, in particular by ultrasonic welding. The side surface areas of the battery cells do not necessarily have to touch each other. A heat conductive plate can be arranged between the side surface areas.
Preferably, at least one insulating body is arranged between the conductors of adjacent battery cells, in particular an insulating strip.
The insulating bodies and the base sections may be aligned along a joint aligning axis. The joint aligning axis may thereby, be defined by coaxially arranged through-holes on both the base section as well as on the insulating bodies. Means of traction, in particular an anchor rod, may be guided through the aligning-holes, with which the insulating bodies and the conductors may be pressed together.
Preferably, the insulating bodies are aligned relative to the conductors, in particular first aligning means of the conductor are brought in engagement with second aligning means of the insulating body. Thereby, preferably, aligning protrusions of the insulating body may be inserted into aligning-holes of the conductor.
Preferably, the battery cells are pressed against each other by means of traction, in particular by an anchor rod. Thereby, preferably, an anchor rod may be guided through a first through-hole of the conductor, in particular in a through-hole of a base section of the conductor, and a second through-hole of the insulating body.
Preferably, a tool component, in particular at least one arm of a welding gun, may be moved along a direction of a module towards the contacting section.
The invention is further illustrated by the following figures. These show:
Each battery cell 1 has two conductors 3, which protrude through the packaging 2 of the battery cell 1. The area of the conductor 3, along which the conductor 3 protrudes through the packaging 2 is the base section 4 of conductor 3. Base section 4 thereby protrudes, the packaging along a sealed area of the packaging. Thereby, an annular space, which is formed between the base section 4 and the packaging 2 is sealed by sealing means, which are not illustrated.
The battery cell 1 has several boundary edges 28. A longest boundary edge 28′ is designed to be straight and defines a direction of a module M. The base section 4 of the conductor 3 is essentially aligned in parallel to the direction of the module M. Each of the conductors 3 has two contacting sections 5, which are arranged on the base section 4 of the conductor 3. The contacting sections 5 are arranged on opposite areas of the base section 4. Contacting sections 5 are bent to be perpendicular, relative to the base section 4, namely in respect to a bending axis K, which is aligned in parallel to the direction of the module M. Contacting sections 5 extend in the direction of adjacent battery cells, and, in particular towards the contacting sections 5 of adjacent battery cells 1. Contacting section 5 is aligned in parallel to a vertical axis S and to a largest side surface area 18′. Contacting areas on the contacting sections 5 of adjacent battery cells 1 thus are in direct contact with each other, when the battery cells 1 are accommodated in a final alignment with each other. When assembled, the contacting sections of adjacent battery cells are therefore in contact with each other. Other connecting spacer elements for connecting the contacting sections 5 are not necessarily required.
As can be seen, in particular from the enlarged sectional view of
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2009 012 948.0 | Mar 2009 | DE | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13255483 | US | |
| Child | 13453941 | US |
