DE102018200608B4 - Cell module for a battery system - Google Patents

Abstract

Cell module (10) for a battery system, comprising:
- at least two individual cells (20) which are electrically interconnected to provide a module voltage of the cell module (10),
- at least one electric heating mat (30) for heating the individual cells (20), wherein the heating mat (30) is integrated in the cell module (10) and is electrically connected to at least one of the individual cells (20) in order to provide a power supply to the heating mat (30) via the module voltage,
wherein at least one conductor element (60) is provided, which comprises an electronics (61) of the cell module (10) and the at least one heating mat (30),
wherein the conductor element (60) is arranged between the individual cells (20) and has a bend so that the shape of the conductor element (60) is adapted to the arrangement of the individual cells (20) in the cell module (10).

Description

The present invention relates to a cell module for a battery system. Furthermore, the invention relates to a battery system with at least two cell modules.

It is known from the prior art that in cell modules for a battery system, the individual cells can be heated by an external heat supply.

In the DE 10 2013 015 757 A1 discloses a cell block for a battery having a plurality of individual cells electrically connected in series and/or parallel with one another and at least one temperature control device arranged on the cell block.

In the DE 10 2005 022 204 B4 discloses a method for heating a battery in a vehicle with a battery heater.

The DE 10 2015 010 983 A1 discloses a battery with a plurality of individual cells or cell blocks electrically connected in parallel and a basic temperature control device for the basic temperature control of all individual cells.

Further batteries with temperature control devices are available in the DE 10 2015 010 925 A1 , US 2016 / 0 028 128 A1 and DE 0 857 348 T1 revealed.

A disadvantage of the known solutions is that complex wiring and increased space requirements are often required to provide the heating, for example, via heating devices. Therefore, it is an object of the present invention to at least partially remedy the disadvantages described above. In particular, it is an object of the present invention to reduce the complexity of the cell module required to provide the heating.

The above object is achieved by a cell module having the features of claim 1 and by a battery system having the features of claim 8. Further features and details of the invention emerge from the respective subclaims, the description, and the drawings. Features and details described in connection with the cell module according to the invention naturally also apply in connection with the battery system according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reciprocal reference is or can always be made.

• - wenigstens zwei Einzelzellen, vorzugsweise Pouch-Zellen, welche elektrisch miteinander verschaltet sind, um eine (elektrische) Modulspannung des Zellmoduls bereitzustellen,
• - wenigstens eine elektrische Heizmatte zum Erwärmen der Einzelzellen.

The object is achieved in particular by a cell module for a battery system, in particular for a vehicle, comprising:

• - at least two individual cells, preferably pouch cells, which are electrically interconnected to provide an (electrical) module voltage of the cell module,
• - at least one electric heating mat to heat the individual cells.

Here, it is provided that the at least one heating mat is integrated in the cell module and is electrically connected to at least one of the individual cells in order to provide energy to the at least one heating mat via the module voltage (i.e., possibly also at least a portion of the module voltage, e.g., only via the voltage of the at least one connected individual cell). This has the advantage that the heating mat can be operated independently of external voltage sources, i.e., it can preferably be provided entirely by the cell module. In this way, the wiring effort and complexity of the cell module are significantly reduced.

Another particular advantage is that heating by means of at least one heating mat enables improved operation of the cell module. This is primarily due to the fact that the electrolyte's influence on the internal resistance deteriorates at low temperatures. This effect influences the performance of the cells and thus also the performance of a vehicle in which the cell module may be used.

A heating mat can advantageously comprise at least one heating element, e.g., at least one heating wire or the like, which is electrically operated for heating. The heating mat is characterized in particular by a flat shape and thus preferably has a much greater extension (e.g., at least 10 times or at least 100 times) in the longitudinal and width directions than in the depth. A heating mat may also be understood to mean a heating foil that is flexibly deformable and/or bendable. Due to the electrical current flow through the heating element, which is enabled by the energy supply to the heating mat, heat radiation can occur. This can be suitable for heating the individual cells of the cell module and thus optimizing the operation of the individual cells. It can be crucial here that the heating mat is operated primarily and specifically to heat the individual cells, i.e., it is not merely parasitic heating.

For example, it can be provided that the energy supply of the at least one heating mat is provided exclusively via the module voltage, i.e., an autonomous energy supply of the heating mat is used in the sense of a self-sufficient system, wherein preferably at least part of the module voltage is supplied to the heating mat for this purpose, wherein the module voltage is preferably provided by the individual cells and/or via an electrical connection of the cell module. The connection, preferably a high-voltage connection, is used, for example, to tap the cell voltage of the individual cells, i.e., the module voltage, and/or to charge the individual cells. For this purpose, the connection is formed in particular on the outside of the cell module, i.e., is designed to be contactable from outside the cell module. For example, the connection serves for the electrical connection to other cell modules in a battery system and/or for the connection to vehicle electronics and/or an on-board electrical system. To provide the connection, at least one or two terminals can be attached to a housing of the cell module, for example. The connection can be connected internally to the individual cells and/or the heating mat via electrical conductors in the housing. This has the advantage that no additional external connections are required to provide the energy supply to the heating mat.

To supply power to the at least one heating mat, the mat can, for example, have an electrical supply connection which is electrically connected to at least one voltage tap of at least one of the individual cells via an electrical conductor, such as at least one conductor track, a cable, or the like. Since the voltages of the individual cells can jointly form the module voltage, at least part of the module voltage can be tapped for the power supply of the heating mat. This has the advantage that the power supply can be provided internally, thus eliminating the need for a dedicated external power supply for the heating mat. In other words, it is not necessary to use a separate heating mat connection to supply power for commissioning the at least one heating mat. This makes it possible for the heating mat to be operated "autonomously" by the cell module. In this way, the cell module can be provided as a closed system. In addition, it can be provided that the module voltage is also supplied externally, in particular via high-voltage connections of the cell module. However, this is not a dedicated power supply for the heating mat, but rather an external supply of the module voltage. This externally supplied module voltage is primarily used to supply the individual cells with power, e.g., for charging. In this case, this module voltage only serves secondarily to supply power to at least one heating mat. When the individual cells are fully charged, the module voltage and thus also the power supply to at least one heating mat can also be provided exclusively internally by the individual cells.

Furthermore, the cell module according to the invention provides at least one conductor element, which comprises electronics of the cell module and the at least one heating mat. A conductor element is understood to be, for example, a (particularly flexible) circuit board or circuit, or a composite thereof, or the like. The conductor element comprises the at least one heating mat, for example, in such a way that at least some of the components of the heating mat are formed by electrical conductors of the conductor element. For example, the conductor element can comprise heating wires of the at least one heating mat. This has the advantage that a space-saving and cost-effective integration of the heating mat in the cell module is possible.

Advantageously, the individual cells are interconnected in parallel or series, thus providing the module voltage (e.g., depending on the circuit, as the sum of the voltages across the individual cells or corresponding to the voltage of an individual cell). For this purpose, at least one module voltage tap can be provided for this interconnection of the individual cells, e.g., via at least one electrically conductive connection between the respective terminals of the individual cells. In order to supply the at least one heating mat with energy, i.e., to enable heating operation of the heating mat, at least one of the individual cells can provide a voltage supply for the heating mat. In other words, the energy supply can be provided via the module voltage, i.e., the voltages of the individual cells. It is advantageous if the portion of the module voltage used for energy supply is adapted to a specification of the heating mat (i.e., in particular, to the energy requirement). For this purpose, a corresponding circuit of the cell module can be used, which can be provided at least partially by an electronic and/or conductor element, e.g., a voltage divider or the like.

It is also advantageous if the conductor element is designed as a flexible printed circuit board, and preferably at least a part of the heating mat, in particular at least one component of the heating mat, is printed on a carrier element (of the conductor element). For this purpose, it is possible, for example, for heating ink, in particular PTC heating ink, to be printed on the printed circuit board or on the carrier element in order to provide a heating element (PTC stands for (which stands for "positive temperature coefficient"). This has the advantage that the heating mat can be accommodated in the cell module in a space-saving manner.

The conductor element can, for example, be designed as at least one printed circuit board, in particular a flexible printed circuit board. A flexible printed circuit board is understood in particular to be an FPC (Flexible Printed Circuit), i.e. an arrangement with printed electrical conductor tracks and/or circuits, which are preferably formed on a flexible base material. This has the advantage that the circuit board can be designed to be flexible and can therefore, if necessary, also be formed into different shapes and geometries (e.g., wound or bent). The conductor tracks and circuits can, for example, be printed onto the base material using an electrically conductive ink. The base material is designed, for example, as a carrier element, in particular a carrier film, and is preferably made of polyimide and/or polyester. The conductor element can have a maximum thickness of 10 micrometers and/or a maximum bending radius of 1 mm.

Furthermore, within the scope of the invention, it is provided that the conductor element is arranged between the individual cells, i.e. between at least two individual cells of the cell module, and in particular between all adjacent individual cells of the cell module. In this case, the conductor element has a bend so that the shape of the conductor element is adapted to the arrangement of the individual cells in the cell module. The conductor element can, for example, be guided at least partially around the individual cells and/or wound and/or wound and/or run in a serpentine manner within the cell module in order to advantageously save space. Furthermore, energy efficiency can be improved by arranging it directly on the individual cells, since the heat does not first have to be transported to the cells via several layers of material.

Furthermore, it is optionally possible for the conductor element and/or the heating mat to be formed as a single piece, and/or for only a single conductor element and/or only a single heating mat to be provided in a cell module. It is advantageous in this case if exactly one conductor element and/or exactly one heating mat is provided in a cell module, since due to its bendability or flexibility it can be arranged between many or all of the individual cells, meaning that no further conductor elements or heating mats are necessary for extensive and large-area heating. Alternatively or additionally, several conductor elements and/or heating mats can be provided, each of which is arranged - in particular in a sandwich-like manner - between individual cells.

Preferably, the conductor element can be designed as a flat conductor with a flexible carrier foil as the carrier element, and preferably as a flexible printed circuit. This enables flexible and adaptable integration into the cell module.

A further advantage within the scope of the invention can be achieved if the electronics of the cell module have at least one electronic switch element, which electrically connects the at least one heating mat to the at least one individual cell in order to switch the power supply of the heating mat, wherein the switch element is preferably designed to be activated externally via a connection (e.g., a pin). Alternatively or additionally, the electronics of the cell module can have a temperature sensor to detect the temperature in the cell module and/or the individual cells. In this way, the heating of the individual cells via the at least one heating mat can be particularly advantageously regulated, e.g., automatically via an electronic control and/or regulating unit. For example, the control and/or regulating unit evaluates the detected temperature in order to actuate the switch element accordingly. The switching element, such as a transistor, relay, or the like, controls, for example, a current flow to the at least one heating mat in order to regulate the heating and thus influence the temperature of the individual cells.

In a further embodiment, the at least one heating mat can be arranged between each pair of adjacent individual cells, preferably directly contacting the respective individual cells, with preferably at least four, at least eight, or at least 10 individual cells being integrated into the cell module. This enables particularly efficient heating, in particular through a sandwich-like arrangement of the heating mat.

Optionally, embodiments of the cell module according to the invention provide for an electrical connection, in particular a high-voltage connection, for electrical connection to an external electrical system to be arranged on a housing of the cell module, whereby the module voltage can be provided and/or influenced externally. The external electrical system is, for example, vehicle electronics or a component of an on-board electrical system, in particular a high-voltage on-board electrical system, of the vehicle and/or a voltage source or a battery management system or the like.

• - wenigstens zwei Einzelzellen, welche elektrisch miteinander verschaltet sind, um eine Modulspannung des Zellmoduls bereitzustellen,
• - wenigstens eine elektrische Heizmatte zum Erwärmen der Einzelzellen.

The invention also relates to a battery system for a vehicle with at least two cell modules, preferably cell modules according to the invention, each comprising:

• - at least two individual cells which are electrically interconnected to provide a module voltage of the cell module,
• - at least one electric heating mat to heat the individual cells.

Here, the heating mat is integrated into the cell module and electrically connected to at least one of the individual cells in order to provide the energy supply to the heating mat via the voltage of this at least one individual cell, i.e., via the module voltage. Thus, the battery system according to the invention offers the same advantages as those described in detail with reference to a cell module according to the invention. The battery system and the individual cells can be designed to be rechargeable and thus form, for example, a rechargeable energy storage device (accumulator) for a vehicle.

The vehicle is designed, for example, as a trackless land vehicle, preferably with a high-voltage electrical system and/or an electric motor. In particular, the vehicle is designed as a passenger car and/or electric vehicle and/or hybrid vehicle. In embodiments of electric vehicles, the vehicle is preferably not provided with an internal combustion engine; it is then powered exclusively by electrical energy.

• 1 eine perspektivische Ansicht eines erfindungsgemäßen Zellmoduls,
• 2 eine weitere perspektivische Ansicht eines erfindungsgemäßen Zellmoduls,
• 3 eine Explosionsdarstellung eines erfindungsgemäßen Zellmoduls,
• 4 eine weitere Explosionsdarstellung eines erfindungsgemäßen Zellmoduls,
• 5 eine Elektronik des Zellmoduls.

Further advantages, features, and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. They show schematically:

• 1 a perspective view of a cell module according to the invention,
• 2 a further perspective view of a cell module according to the invention,
• 3 an exploded view of a cell module according to the invention,
• 4 a further exploded view of a cell module according to the invention,
• 5 an electronics of the cell module.

In the following figures, identical reference numerals are used for the same technical features, even in different embodiments.

In 1 A cell module 10 according to the invention is shown schematically, in which a housing 40 of the cell module 10 can be seen in the assembled state. At least one heating mat 30, which serves to heat individual cells 20 of the cell module 10, is not visible from the outside. Thus, the at least one heating mat 30 is completely integrated into the cell module 10. The housing 40 has at least one front end plate 41, a base 42, and at least one side wall 43. A heating mat 30 can optionally be provided on each of these housing elements 41, 42, 43. This enables heating adapted to the arrangement of the individual cells 20 with high heating efficiency.

It can also be seen that a connection 50, i.e., a terminal of the cell module 10, is arranged on the housing 40. This makes it possible to establish an electrically conductive connection to the individual cells 20 and thereby tap the module voltage.

A particular advantage is that this module voltage is also used to supply power to at least one heating mat 30. Thus, no additional external connection is necessary for the power supply of the heating mat 30.

In 2 It can be seen that the heating mat 30 can be arranged over a large area on one side of the housing (e.g. a housing element 41, 42, 43), in particular extending completely or predominantly or at least 90% on this side of the housing or on this housing element 41, 42, 43. In this case, the heating mat 30 can be arranged according to 2 at the top or (alternatively or additionally) according to 3 at the bottom 42 of the housing 40 in order to provide the most efficient heating of the individual cells 20.

According to 3 It can be seen from the schematic representation shown therein that the heating mat 30 can be integrated into a conductor element 60, e.g., a flexible printed circuit board. This can include, in addition to the components of the heating mat 30, conductor tracks and/or electronics 61 of the cell module 10. The electronics 61 is in 5 shown by way of example with a switch element 63 and a temperature sensor 64. Furthermore, it can be seen that the printed circuit board can have a carrier element 62 as the base material, which is particularly flexible and bendable.

An advantage of the flexible design of the support element 62 and thus also of the heating mat 30 is shown by 4 This allows the heating mat 30 to be laid and/or wound flexibly and evenly between the individual cells 20 in order to transfer the heat to the individual cells 20 in the most space-saving manner. It is also possible to provide several heating mats 30, which may be arranged separately and/or spaced apart from one another. For example, at least two or at least three or at least five heating mats 30 or at least one heating mat 30 per individual cell 20 can be provided. Shown in 4 For example, a first heating mat 31 and a second heating mat 32, as well as an nth heating mat 34, where n can be any positive integer. Alternatively or additionally, a heating mat 30 can also be arranged in the region of a housing element 44.

The above explanation of the embodiments describes the present invention exclusively within the scope of examples. Of course, individual features of the embodiments can be freely combined with one another, provided they are technically feasible, without departing from the scope of the present invention.

List of reference symbols

10

Cell module

20

single cell

30

heating mat

31

first heating mat

32

second heating mat

34

nth heating mat

40

Housing

41

End plate

42

Floor

43

side wall

44

additional housing element

50

connection, terminal

60

Conductor element, flexible printed circuit board

61

electronics

62

Support element

63

Switch element

64

Temperature sensors

Claims (8)

A cell module (10) for a battery system, comprising: - at least two individual cells (20) electrically interconnected to provide a module voltage of the cell module (10), - at least one electrical heating mat (30) for heating the individual cells (20), wherein the heating mat (30) is integrated in the cell module (10) and is electrically connected to at least one of the individual cells (20) to provide power to the heating mat (30) via the module voltage, wherein at least one conductor element (60) is provided, which comprises electronics (61) of the cell module (10) and the at least one heating mat (30), wherein the conductor element (60) is arranged between the individual cells (20) and has a bend such that the shape of the conductor element (60) is adapted to the arrangement of the individual cells (20) in the cell module (10). Cell module (10) according to Claim 1 , characterized in that the energy supply of the at least one heating mat (30) is provided exclusively via the module voltage, wherein for this purpose at least part of the module voltage is supplied to the heating mat (30), wherein the module voltage is provided by the individual cells (20) and/or via an electrical connection (50) of the cell module (10). Cell module (10) according to Claim 1 or 2 , characterized in that the conductor element (60) is designed as a flexible printed circuit board, and at least one component of the heating mat (30) is printed on a carrier element (62) of the printed circuit board. Cell module (10) according to Claim 3 , characterized in that the conductor element (60) is designed as a flat conductor with a flexible carrier film as the carrier element (62), and is preferably designed as a flexible printed circuit. Cell module (10) according to one of the preceding claims, characterized in that an electronics unit (61) of the cell module (10) has at least one electronic switch element (63) which electrically connects the at least one heating mat (30) to the at least one individual cell (20) in order to switch the energy supply of the heating mat (30), wherein the switch element (63) is preferably designed to be externally activatable via a connection (50). Cell module (10) according to one of the preceding claims, characterized in that the at least one heating mat (30) is arranged between each pair of adjacent individual cells (20) and preferably directly contacts the respective individual cells (20), wherein preferably at least four or at least eight or at least 10 individual cells (20) are integrated in the cell module (10). Cell module (10) according to one of the preceding claims, characterized in that an electrical high-voltage connection for electrical connection to an external electrical system is provided on a housing (40) of the cell module (10), whereby the module voltage can be provided and/or influenced externally. A battery system for a vehicle with at least two cell modules (10), each comprising: - at least two individual cells (20) which are electrically interconnected to provide a module voltage of the cell module (10), - at least one electrical heating mat (30) for heating the individual cells (20), wherein the heating mat (30) is integrated in the cell module (10) and is electrically connected to at least one of the individual cells (20) to provide the energy supply to the heating mat (30) via the module voltage, wherein at least one conductor element (60) is provided, which comprises electronics (61) of the cell module (10) and the at least one heating mat (30), wherein the conductor element (60) is arranged between the individual cells (20) and has a bend such that the shape of the conductor element (60) is adapted to the arrangement of the individual cells (20) in the cell module (10).

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