BATTERY MODULE WITH FLEXIBLE INTERCONNECTOR

Abstract

A battery module includes: a plurality of aligned battery cells having differently-oriented surfaces; a cell supervision circuit (CSC) configured to receive signals corresponding to the voltage and/or temperature of at least one of the battery cells; and a flexible interconnector comprising a strip-shaped flexible printed circuit (FPC). The FPC includes a first insulating main surface, a second insulating main surface opposite the first insulating main surface, and a plurality of thermally and/or electrically conducting lines between the first insulating main surface and the second insulating main surface. Each of the conducting lines has a contact portion exposed by a contact aperture in the first insulating main surface and/or in the second insulating main surface and a connecting portion for connection to the CSC, and the flexible interconnector wraps around the battery cells such that the contact portions contact the differently-oriented surfaces of the battery cells.

Claims

1. A battery module comprising: a plurality of aligned battery cells having differently-oriented surfaces; a cell supervision circuit (CSC) configured to receive signals corresponding to the voltage and/or temperature of at least one of the battery cells; and a flexible interconnector comprising a strip-shaped flexible printed circuit (FPC), the FPC comprising a first insulating main surface, a second insulating main surface opposite the first insulating main surface, and a plurality of thermally and/or electrically conducting lines between the first insulating main surface and the second insulating main surface, wherein each of the conducting lines has a contact portion exposed by a contact aperture in the first insulating main surface and/or in the second insulating main surface and a connecting portion for connection to the CSC, and wherein the flexible interconnector wraps around the battery cells such that the contact portions contact the differently-oriented surfaces of the battery cells.

2. The battery module according to claim 1, wherein the battery cells are cylindrical battery cells, and wherein the flexible interconnector wraps around the battery cells such that the contact portions contact base surfaces and lateral surfaces of the battery cells.

3. The battery module according to claim 1, wherein the battery cells are prismatic battery cells, each of the prismatic battery cells comprising a cell case and a cap assembly on the cell case, and wherein the flexible interconnector wraps around the prismatic battery cells such that contact portions contact the cell cases and the cap assemblies of the prismatic battery cells.

4. The battery module according to claim 1, further comprising a heat exchanger in thermal contact with the plurality of battery cells, wherein the flexible interconnector wraps around the battery cells and the heat exchanger such that the contact portions contact the battery cells and the heat exchanger.

5. The battery module according to claim 1, further comprising a plurality of busbars, each of the busbars interconnecting cell terminals of at least two of the battery cells, wherein the flexible interconnector wraps around battery cells and the busbars such that the contact portions contact the battery cells and the busbars.

6. The battery module according to claim 1, wherein the connecting portions of at least some of the conducting lines are arranged at a terminal end of the strip-shaped FPC.

7. The battery module according to claim 6, wherein each of the conducting lines extends across the entire length of the FPC and has a first connecting portion at a first terminal end and a second connecting portion at a second terminal end.

8. The battery module according to claim 6, wherein the flexible interconnector further comprises a connector plug attached to a terminal end of the FPC, the connector plug being connected to at least one of the conducting lines and being configured to be electrically connected to the CSC.

9. The battery module according to claim 1, wherein the connecting portions of at least some of the conducting lines are arranged at a center part of the FPC.

10. The battery module according to claim 1, wherein each of the contact apertures exposes one or more of the conducting lines.

11. The battery module according to claim 1, wherein a first subset of the conducting lines is configured to measure electric voltages at respective first contact portions, and wherein a second subset of the conducting lines is configured to measure temperatures at respective second contact portions.

12. The battery module according to claim 11, further comprising thermistors at the second contact portions of the second subset of the conducting lines.

13. A method for manufacturing a battery module, the method comprising: providing a pre-module comprising a plurality of aligned battery cells having differently-oriented surfaces; attaching a terminal end of a flexible interconnector to the pre-module, the flexible interconnector comprising a strip-shaped flexible printed circuit (FPC), the FPC comprising a first insulating main surface, a second insulating main surface opposite the first insulating main surface, and a plurality of thermally and/or electrically conducting lines between the first insulating main surface and the second insulating main surface, each of the conducting lines having a contact portion exposed by a contact aperture in the first insulating main surface and/or the second insulating main surface; and wrapping the flexible interconnector around the pre-module such that the contact portions contact the differently-oriented surfaces of the battery cells.

14. The method according to claim 13, wherein the pre-module further comprises: a cell supervision circuit (CSC) configured to receive signals corresponding to the voltage and/or temperature of the battery cells; a heat exchanger in thermal contact with the plurality of battery cells; and a busbar interconnecting cell terminals of at least two of the battery cells, wherein the wrapping the flexible interconnector around the pre-module comprises wrapping the flexible interconnector around the pre-module such that the contact portions contact the heat exchanger and/or the busbar, and wherein the attaching the terminal end of the flexible interconnector to the pre-module comprises attaching the terminal end of the flexible interconnector to the CSC.

15. The method according to claim 14, wherein electric connections between the contact portions of the wrapped flexible interconnector and the differently-oriented surfaces of the battery cells, the heat exchanger, and/or the busbar are formed by welding, stamping, brazing, and/or soldering.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Aspects and features of the present invention will become more apparent to those of ordinary skill in the art by describing, in detail, exemplary embodiments thereof with reference to the attached drawings, in which:

[0038] FIG. 1 is a perspective view of a battery module according to an embodiment;

[0039] FIG. 2 is a schematic cross sectional view of a flexible printed circuit (FPC) of a flexible interconnector in the battery module shown in FIG. 1;

[0040] FIG. 3 is a schematic perspective view of part of a side surface of the battery module shown in FIG. 1;

[0041] FIG. 4 is a schematic perspective view of a bottom surface of the battery module shown in FIG. 1;

[0042] FIG. 5 is a schematic exploded view of the battery module shown in FIG. 1; and

[0043] FIGS. 6(A) to 6(D) schematically illustrate steps of a method for manufacturing a battery module according to an embodiment.

DETAILED DESCRIPTION

[0044] Reference will now be made, in detail, to embodiments, examples of which are illustrated in the accompanying drawings. Aspects and features of the exemplary embodiments, and implementation methods thereof, will be described with reference to the accompanying drawings. The present invention, however, may be embodied in various different forms and should not be construed as being limited to the embodiments illustrated herein. Rather, these embodiments are provided as examples so that this disclosure will be thorough and complete and will fully convey the aspects and features of the present invention to those skilled in the art. Processes, elements, and techniques not considered necessary for those having ordinary skill in the art to have a complete understanding of the aspects and features of the present invention may not be described.

[0045] It will be understood that when an element or layer is referred to as being “on,” “connected to,” or “coupled to” another element or layer, it may be directly on, connected, or coupled to the other element or layer or one or more intervening elements or layers may also be present. When an element or layer is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. For example, when a first element is described as being “coupled” or “connected” to a second element, the first element may be directly coupled or connected to the second element or the first element may be indirectly coupled or connected to the second element via one or more intervening elements.

[0046] In the figures, dimensions of the various elements, layers, etc. may be exaggerated for clarity of illustration. The same reference numerals designate the same elements. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Further, the use of “may” when describing embodiments of the present invention refers to “one or more embodiments of the present invention.” In the following description of embodiments of the present invention, the terms of a singular form may include plural forms unless the context clearly indicates otherwise. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. Also, the term “exemplary” is intended to refer to an example or illustration. As used herein, the terms “use,” “using,” and “used” may be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively. As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art.

[0047] It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of example embodiments.

[0048] As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. Further, if the term “substantially” is used in combination with a feature that could be expressed using a numeric value, the term “substantially” denotes a range of +/−5% of the value centered on the value.

[0049] Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the FIGS. is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” or “over” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0050] FIG. 1 is a schematic perspective view of a battery module 50 according to an embodiment. The battery module 50 includes a plurality of cylindrical battery cells 10, each having a pair of opposing circular base surfaces 14, which are connected to each other by a lateral surface 15. Each of the battery cells 10 is disposed within a respective cell case 13. The cell case 13 includes (e.g., is divided into) an upper cell case and a lower cell case, and a central part of the lateral surface 15 of each of the battery cells 10 is not covered by the cell case 13 (e.g., the central part of the lateral surface 15 of the battery cells 10 is exposed between the upper cell case and the lower cell case of the cell case 13).

[0051] The plurality of battery cells 10 is disposed on a base plate 42, and the base plate 42 is configured as a lower heat exchanger 40.1 for transporting heat emitted by the battery cells 10 via their lower base surfaces 14a away. A top cover 41 is disposed on top of the plurality of battery cells 10 and is configured as an upper heat exchanger 40.2 for transporting heat emitted by the battery cells 10 via their upper base surfaces 14b away. On top of the top cover 41, a cell supervision circuit (CSC) 20 is provided, and the CSC 20 is configured to receive signals corresponding to the voltage and temperature of the battery cells 10 of the battery module 50. The CSC 20 is further configured to communicate with a battery management system and to control voltages of the battery cells 10 of the battery module 50 via active or passive balancing.

[0052] The battery module 50 further includes a flexible interconnector 30 with (or including) a strip-shaped flexible printed circuit (FPC) 35, a cross section of which is shown schematically in FIG. 2. The FPC 35 comprises a first insulating main surface 31 and a second insulating main surface 32 opposite to the first insulating main surface 31 (see, e.g., FIG. 2). A plurality of conducting lines 33 is disposed between the insulating main surfaces 31, 32 such that they are electrically and/or thermally insulated from the surroundings. As shown in FIG. 1, a first connection portion (e.g., a first terminal end) 371 of the FPC 35 (e.g., a first connecting portion 371 of both connecting portions 37 of the FPC 35) is connected to the CSC 20 via a first connector plug 38a (e.g., a first connector plug 38a of both connector plugs 38), and a second connection portion (e.g., a second terminal end) 372 of the FPC 35 (e.g., a second connecting portion 372 of both connecting portion 37 of the FPC 35) is connected to the CSC 20 via a second connector plug 38b (e.g., a second connector plug 38b of both connector plugs 38). The flexible interconnector 30 thus forms an electric loop starting and terminating at the CSC 20.

[0053] As further shown in FIG. 2, the conducting lines 33 of the FPC 35 include a plurality of contact portions 34a, 34b, 34c, in which (or at where) the conducting lines 33 are exposed by contact apertures 36a, 36b, 36c in the first insulating main surface 31 (in the case of the contact aperture 36b) or in the second insulating main surface 32 (in the case of the contact apertures 36a, 36c). For example, an electric and/or thermal connection can be established between the conducting line(s) 33 and an adjacent object at the contact portion 34a, 34b, 34c via the respective contact aperture 36a, 36b, 36c. By wrapping the FPC 35 around the battery module 50, voltages and/or temperatures at its constituents (e.g., of all or substantially all of the battery cells 10 therein) may be measured.

[0054] As illustrated in FIG. 1, the FPC 35 of the flexible interconnector 30 wraps around the battery module 50 and extends over various constituent elements thereof. Starting from the first terminal end 371, the FPC 35 is guided underneath the top cover 41 and between the battery cells 10, such as by going up and down between the battery cells 10 between the top cover 41 and the base plate 42. The FPC 35 then extends along a lower side of the base plate 42 and extends upwardly along one of the battery cells 10 towards the second terminal end 372 at the CSC 20. The FPC 35 includes a plurality of contact portions 34 along its extension length in electric and/or thermal contact with a plurality of measurement points of the battery module 50.

[0055] As shown in FIG. 2, the FPC 35 extends along a battery cell 10, a heat exchanger (e.g., the lower or upper heat exchanger 40.1, 40.2), and a busbar 45. At each of these components, one of the first and second main insulating surfaces 31, 32 has a contact aperture 36 exposing a contact portion 34 of a conducting line 33. In the FPC 35, different contact apertures 36 expose different conducting lines 33. For example, a first contact aperture 36a in the second insulating main surface 32 adjacent to a busbar 45 exposes a conducting line 33 that contacts the busbar 45 in the region of a first contact portion 34a. The conducting line 33 is electrically connected to the busbar 45 by, for example, soldering. A third contact aperture 36c in the second main insulating surface 32 is disposed near the upper heat exchanger 40.2 and exposes a third contact portion 34c. However, the upper heat exchanger 40.2 is adjacent to the first main insulating surface 31 such that no electric connection is established between the upper heat exchanger 40.2 and the conducting line 33. A thermistor 39a is disposed in the third contact aperture 36c; thus, the thermistor 39a is in the vicinity of the upper heat exchanger 40.2. The ohmic resistance of the thermistor (e.g., a negative temperature coefficient (NTC) thermistor) depends on the temperature of the thermistor 39a, and a voltage drop in the respective conducting line 33 is indicative of a temperature of the thermistor 39a. Another thermistor 39b is disposed in a second contact aperture 36b that exposes a second contact portion 34b and that is adjacent to and faces away from the battery cell 10. The voltage drop over the thermistor 39b is indicative of a temperature of the battery cell 10 (e.g., of the corresponding battery cell 10).

[0056] As shown in FIG. 3, the FPC 35 is attached to a surface of the battery cells 10 to measure the temperatures thereof. For example, the FPC 35 is attached to a part of the lateral surface 15 of the battery cells 10 that is not covered by the cell case 13. The thermistor 39 (schematically represented by a dark dot) is disposed in the attachment portion of the FPC 35 and is thus influenced by the temperature of the nearby (e.g., corresponding) battery cell 10. As shown in FIG. 4, the FPC 35 extends over a plurality of busbars 45 at the upper base surface 14b of the battery cells 10 to measure voltage. The FPC 35 includes the plurality of contact portions 34 respectively exposing other ones of the conducting lines 33. Some of the plurality of contact portions 34 are adjacent to and face towards one of the busbars 45. Hence, an electric connection is established between the respective conducting line 33 and the respective busbar 45, and hence, a voltage potential at the busbar 45 is provided via the corresponding conducting line 33 to a respective voltage measurement input at the CSC 20, for example, via a pin of a connector plug 38.

[0057] FIG. 5 is a schematic exploded view of the battery module shown in FIG. 1 with the base plate 42 omitted for ease of description. The cell cases 13 have openings that are aligned with the base surfaces 14 of the battery cells 10 to enable the battery cells 10 to contact other elements.

[0058] In FIG. 5, the second terminal end 372 of the FCP 35 and a portion of the FCP 35 between the second terminal end 372 and a middle portion of the FCP 35 connected to lateral surfaces 15 of the battery cells 10 are omitted for ease of description. The FCP 35 as illustrated in FIG. 5 extends underneath the top cover 41, along the outer lateral surfaces 15 of the battery cells 10, along the lower base surfaces 14a of the battery cells 10, and along the inner lateral surfaces 15 of the battery cells 10.

[0059] FIGS. 6(A) to 6(D) schematically illustrate steps of a method for manufacturing a battery module 50 according to an embodiment. As shown in FIG. 6(A), a pre-module 55 is provided that includes a plurality of cylindrical battery cells 10 disposed in two-part cell cases 13 as described above. At the lower and upper base surfaces 14a, 14b of the battery cells 10, the terminals of the battery cells 10 are interconnected in parallel and/or in series via a plurality of busbars 45. The plurality of aligned battery cells 10 have surfaces in different orientations, for example, the lateral surfaces 15 of the aligned battery cells 10 face in different orientations. The pre-module 55 is disposed on a table (e.g., a rotatable table) 60 that is configured to be rotated during the manufacturing method.

[0060] As further shown in FIG. 6(A), a terminal end of a flexible interconnector 30 is attached to the pre-module 55 via a self-adhesive portion thereof that is adhered to the pre-module 55 via, for example, a robot arm of a feeding machine. Therein, the flexible interconnector 30 includes the strip-shaped FPC 35 as described above with a first insulating main surface 31, a second insulating main surface 32 opposite the first insulating main surface 31, and a plurality of thermally and/or electrically conducting lines 33 disposed between the first insulating main surface 31 and the second insulating main surface 32. Further, each conducting line 33 includes at least one contact portion 34 that is exposed by (or exposed through) a contact aperture 36 in the first insulating main surface 31 or the second insulating main surface 32.

[0061] As show in FIGS. 6(B) to 6(D), after attachment of the terminal portion of the flexible interconnector 30, the rotatable table 60 starts to spin while the flexible interconnector 30 is kept under tension by the robot arm of the feeding machine. As the rotatable table 60 spins, the flexible interconnector 30 is wrapped around the pre-module 55 such that the contact portions 34 contact different surfaces at different orientations of the battery module 50. A plurality of busbars 45 disposed on lower base surfaces 14a of the battery cells 10 is contacted by the flexible interconnector 30, for example, by a plurality of the respective contact portions 34 that are exposed by respective contact apertures 36, as shown in FIG. 6(B). Further, the lateral surfaces 15 of the battery cells 10 contact respective contact portions 34 for temperature measurements as shown in, for example, FIG. 6(C). Further, respective contact portions 34 of the flexible interconnector 30 contact a plurality of busbars 45 disposed on the upper base surfaces 14b of the battery cells 10 for connecting them to respective conducting lines 33 as shown in FIG. 6(D). These conducting lines 33 can then be connected to respective voltage measurement pads of the cell supervision circuit 20.

[0062] After the flexible interconnector 30 is wrapped around the pre-module 55, the electric connections between the contact portions 34 of the wrapped flexible interconnector 30 and at least one of the differently oriented surfaces of the battery cells 10, at least one heat exchanger 40.1, 40.2, and at least one busbar 45 are provided by welding and/or soldering. Hence, the conducting lines 33 are connected to the adjacent component of the pre-module 55 in the region of the contact portion 34 and via the contact aperture 36. Then, the CSC 20 is attached to the pre-module 55 to form the battery module 50, and a connector plug 38 at a terminal end of the flexible interconnector 10 is connected to the CSC 20.

[0063] The electronic or electric devices and/or any other relevant devices or components according to embodiments of the present invention described herein may be implemented utilizing any suitable hardware, firmware (e.g., an application-specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, the various components of these devices may be formed on one integrated circuit (IC) chip or on separate IC chips.

[0064] Further, the various components of these devices may be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or formed on one substrate. Further, the various components of these devices may be a process or thread, running on one or more processors, in one or more computing devices, executing computer program instructions and interacting with other system components for performing the various functionalities described herein. The computer program instructions are stored in a memory which may be implemented in a computing device using a standard memory device, such as, for example, a random access memory (RAM). The computer program instructions may also be stored in other non-transitory computer readable media such as, for example, a ROM, flash drive, or the like. Also, a person of skill in the art should recognize that the functionality of various computing devices may be combined or integrated into a single computing device, or the functionality of a particular computing device may be distributed across one or more other computing devices without departing from the scope of the invention's embodiments.

[0065] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present specification and should not be interpreted in an idealized or overly formal sense, unless expressly defined so.

SOME REFERENCE NUMERALS

[0066] 10 battery cell [0067] 13 cell case [0068] 14 base surface [0069] 14a lower base surface [0070] 14b upper base surface [0071] 15 lateral surface [0072] 20 cell supervision circuit (CSC) [0073] 30 flexible interconnector [0074] 31 first insulating main surface [0075] 32 second insulating main surface [0076] 33 conducting lines [0077] 34 contact portion [0078] 34a first contact portion [0079] 34b second contact portion [0080] 34c third contact portion [0081] 35 strip-shaped flexible printed circuit (FPC) [0082] 36 contact aperture [0083] 36a first contact aperture [0084] 36b second contact aperture [0085] 36c third contact aperture [0086] 37 connecting portion [0087] 371 first connecting portion [0088] 372 second connecting portion [0089] 38 connector plug [0090] 39 thermistor [0091] 40.1 lower heat exchanger [0092] 40.2 upper heat exchanger [0093] 41 top cover [0094] 42 base plate [0095] 45 busbar [0096] 50 battery module [0097] 55 pre-module [0098] 60 rotating table