DE102015221739A1 - Battery module with clamping mechanism - Google Patents

Abstract

The present invention relates to a battery module having at least one battery cell and at least one module wall, wherein the battery cell is at least partially surrounded by the module wall and the module wall is in operative connection with at least one clamping mechanism, so that upon deformation of the battery cell due to a change in volume of the clamping mechanism of the deformation mechanically counteracts the battery cell.

Description

The present invention relates to a battery module according to the first independent claim, comprising at least one battery cell and at least one module wall, wherein the battery cell is at least partially surrounded by the module wall and the module wall is in operative connection with a clamping mechanism. Moreover, the invention relates to a battery with at least one battery module according to the invention according to the further independent claim.

State of the art

The battery cells, in particular of lithium-ion batteries, are usually installed in a module, wherein usually between 5 and 20 cells are arranged to form a battery module. Several battery modules are then combined to form a battery, this being done by a parallel or series connection of the battery cells. Over time, there are aging-related changes in the battery cells and the Batteriemodulwandung. In this case, the battery cells and thus the Batteriemodulwandungen expand due to aging and associated gas formation or by temperature increases, so that the volume of the battery cells and the battery module compared to the original state is increased. Even with different states of charge (state of charge) it comes to changes in volume of the battery cells, so that forces act on the modulus wall, which can cause a deformation of the module wall. This undesired change in volume of the battery cells has hitherto been attempted to counteract, at least to a certain extent, by compensating elements within the battery cells, which consist in particular of a deformable material.

From the DE 10 2009 052 508 A1 a generic compensating element is known which consists of a porous and deformable material and is arranged between the battery cells.

Disclosure of the invention

The battery module according to the first independent claim has at least one battery cell and at least one module wall, wherein the battery cell is at least partially surrounded by the module wall and the module wall is in operative connection with a clamping mechanism. In a deformation of the battery cell due to a change in volume, the clamping mechanism of the deformation of the battery cell mechanically counteracts. In this way, on the one hand, the service life of the individual battery cell can be increased and, on the other hand, less expensive materials can be used since the forces acting on them can be significantly reduced (by a factor of 2 to 5). A battery cell according to the invention is an electrical energy storage, in particular an electrochemical energy storage and / or electrostatic energy storage.

Further features and details of the invention will become apparent from the dependent claims, the description and the drawings. In this case, features and details that have been described in connection with the battery module according to the invention, of course, also in connection with the battery according to the invention and in each case vice versa, so with respect to the disclosure of the individual aspects of the invention always reciprocal reference is or may be.

The clamping mechanism according to the invention allows expansion of the battery cell and thus the battery module up to a definable volume, wherein at the same time force is exerted by the clamping mechanism on the module wall. Thus, the expansion can be at least tlw. Set or allowed to be controlled. This ensures the integrity of the system and provides propagation protection for the battery module. Consequently, the tensioning mechanism of the present invention acts as a limit to the expansion of the battery module while permitting breathing of the battery module to a definable extent. The tensioning mechanism according to the invention thus causes typically high expansion forces arising from the breathing and the aging of the cell to be absorbed and / or counteracted, at least in parts, so that expensive valuable substances for the module walls can be at least partially saved. If the battery module expands as a result of an increase in temperature, gas formation or due to the state of charge, the clamping mechanism assumes a defined deformation movement, so that the temperature of the battery module and / or the battery module, the wall of the battery module at least with changes in temperature, state of charge or after degassing tlw. Can be brought back to its original form. In this case, the clamping mechanism is preferably designed such that in the initial state of the battery cells and the battery module, in which there is no increase in volume, a counterforce on the battery cell is at least tlw. Avoided so that the battery cell is not compressed or pressed in the initial state, causing damage to the Modulwandung or capacity losses are effectively prevented. In addition, the clamping mechanism allows the saving of screws or bolts, which hold the battery cells together to form a module, which makes the installation and / or production of a battery module more costly and especially when replacing individual battery cells leads to a security risk. Accordingly, it can be dispensed with a screwing or holding together by a metallic cell tape, so that a severing of the cell tape when changing individual battery cells is no longer necessary.

Due to the defined and, to a certain extent, limited dimensions of the battery module, costs for material selection for the module wall can be saved. Accordingly, cheaper steels or plastic can be used as the material for the module wall, since the forces acting on the modulus wall can be reduced.

According to the invention, it is conceivable that the clamping mechanism at least partially surrounds the battery module on at least three sides, preferably on four sides, so that a uniform expansion of the battery module can be allowed and counteracted up to a defined point. It is also conceivable that a plurality of clamping mechanisms are arranged on the battery module, so that in particular at the neuralgic points of the module extension, a deformation can be mechanically counteracted. Preferably, the clamping mechanism is arranged on the sides of the battery module or the battery cells, which have the largest cross-sectional area, since an extension, this direction is greatest.

In the context of the invention, it is conceivable that the clamping mechanism is variable in length and / or has a length limitation. Preferably, the change in length of the clamping mechanism is limited to a defined extent, so that it is foreseeable how large the change in length of the battery module due to deformation can be maximum. A change in length of the clamping mechanism can according to the invention z. B. be achieved by the use of different materials or a movable clamping mechanism. Different materials with different moduli of elasticity allow a change in the length of the tensioning mechanism to a limited extent, whereby materials with a lower modulus of elasticity can be combined with materials with a high modulus of elasticity. In this case, movable means that the tensioning mechanism is designed to be movable and / or supported in such a way that at least the deformation movements (expansion / compression) are made possible. Parts of the clamping mechanism and / or the Modulwandung z. B. movably mounted by means of roller, needle or ball bearings.

A length limitation in the sense of the invention may, for example, be a mechanical stop which, after reaching a defined volume extension, limits it at the previously defined point at which the mechanical stop is arranged. This may be a further component on the clamping mechanism, wherein the length limitation is designed such that the forces due to the volume expansion is absorbed by the length limitation and counteracted, so that a further expansion is prevented. For the purposes of the invention, this may also be a component with such a high modulus of elasticity that further deformation is prevented by the length limitation, so that the clamping mechanism does not permit any further change in volume when the length limit is reached, but instead counteracts the deformation in such a way that the Battery module is maintained in the achieved state of expansion or at least tlw. Compressed back to the original shape. The length limitation can also be arranged on at least one side of the battery module, wherein preferably length limits are arranged on at least two sides of the battery module, so that a uniform expansion of the battery module is achieved.

It is inventively conceivable that the module wall and / or the clamping mechanism is spring loaded. Spring-loaded in the sense of the invention means that the module wall and / or the clamping mechanism has at least one spring element, which allows a deformation of the battery module as a result of a change in volume of the battery cell. The spring element preferably has a spring constant and / or length which allows limited deformation due to a volume change. Accordingly, it can be controlled via the spring constant or the spring length, how large the force is exerted on the battery module in particular on the module wall by the clamping mechanism. In addition, a plurality of spring elements can be used, wherein the spring elements may have different spring constants and / or lengths from each other, so that, for example, small volume changes are absorbed by springs with a small spring constant and / or length, so that the mechanical loads on the module wall the battery module are kept low and only when a critical change in length, the mechanical forces are increased to the modulus by springs with a larger spring constant. Accordingly, a length limitation can be realized by the use of different spring elements with mutually different spring constants and / or lengths. In addition, it is conceivable that individual Spring elements such spring constants and / or lengths have that the deformation of the battery module is limited by the length and / or the spring constant of the spring element of the at least one spring element. A spring-loaded clamping mechanism and / or a spring-loaded module wall is preferably arranged on at least one side of the battery module, wherein particularly preferably at least two opposite sides of the battery module may be spring-loaded. As a result, a uniform volume change is achieved and limited by the clamping mechanism, so that a controlled expansion of the battery module can be achieved. In the context of the invention, the spring elements may be coil springs, torsion or torsion bar springs, spiral springs or elastomer springs. These can be dimensioned depending on the available space and expected volume change and the associated force and arranged on the module wall and / or the clamping mechanism. The spring elements serve as storage for potential energy and can produce a frictional connection between the module wall and the clamping mechanism or the module wall and the battery cells. Demensprechend a restoring force of the spring elements is exerted on the Modulwandung and / or the clamping mechanism, so that the springs record a change in shape of the module and / or the clamping mechanism and a decrease in the volume change, a mechanical force acts on the battery cells so that they compressed in their original form become.

According to the invention, it is conceivable that the clamping mechanism has at least one cylinder and / or shock absorber and / or a telescopic rail. A cylinder according to the invention may comprise an inner body and a cylinder sleeve, wherein the inner body is movably disposed in the sleeve and preferably has a length limitation, which constitutes a mechanical stop for the clamping mechanism. Accordingly, a defined change in length of the clamping mechanism can be achieved via the cylinder, so that due to the change in volume of the battery cells of the cylinder receives the movement and on reaching the length limitation, so mechanically acts on the Modulwandung that no further expansion of the battery module is made possible. In a development, the tensioning mechanism may comprise a shock absorber, wherein the shock absorber can absorb the forces due to the volume change and limit them to a defined extent. It may be a friction damper, a hydraulic damper, a gas spring or a hydropneumatic. Preferably, the shock absorber may have an adjustable tension and compression stage, about which the force required for compression or compression of the shock absorber is adjustable. If the tension and / or the pressure level is increased, more energy is needed for compressing the shock absorber or pulling the shock absorber apart. If the tension and / or the pressure level is set smaller, less force is required for the tensile and / or the pressure movement. Accordingly, the tension and / or pressure stage, in particular in combination with a mechanical stop of the shock absorber, provides a further possibility for achieving a limited change in length of the module wall and / or the tensioning mechanism. Furthermore, it is conceivable that the clamping mechanism has a telescopic rail, wherein the telescopic rail preferably has at least two parts which are slidable into one another. In addition, the telescopic rail may preferably have a length limitation, so that a tensile and / or a pressure movement of the at least two components of the telescopic rail, which allow a change in length, are limited in their movement. In this case, the length limitation can be achieved by a slot and a corresponding complementary trained stop element, so that a change in length can be defined by the geometry of the slot on the telescopic rail. If the stop element reaches one end of the oblong hole, then either the tensile and / or the pressure movement is limited and a compression or expansion of the battery module is thereby stopped.

In the context of the invention, the clamping mechanism may be self-locking. Accordingly, the tensioning mechanism is limited by friction resistance against further slippage of the tensioning mechanism. The static friction, which is present on the clamping mechanism, z. B. be influenced by the surface roughness of two support surfaces of the clamping mechanism, the material pairing or heat. If the battery heats up during operation, for example, materials may be used which expand in such a way that, for example, in the case of a telescope mechanism, the two elements which are movable into one another jam at least in sections such that self-locking can be achieved by high static friction. A self-locking clamping mechanism allows a cost-effective design for a length limitation, which in particular is temperature-dependent feasible.

Advantageously, the clamping mechanism and / or the module wall may comprise a plastic or a metallic material. The use of plastic in the module wall allows cost-effective production, which is particularly feasible that the Clamping mechanism absorbs a large part of the mechanical forces due to the module change. Thus, the module wall can be inexpensively made of a plastic, preferably thermosets or thermoplastics are used. Thermoplastics are inexpensive and easy to manufacture, while allowing limited deformability of the module wall. Thermosets are characterized by mechanical and chemical resistance even at elevated temperatures and are therefore suitable for use in battery modules. Material combinations can also be used in the module wall, so that plastics and / or metals with a higher mechanical resistance are used at the critical points where the volume change is greatest. The clamping mechanism can be made of thermosets and / or thermoplastics and / or a combination of these, so that different material properties can be combined. A clamping mechanism made of a plastic is particularly suitable in battery modules, as they are performed both mechanically and chemically resistant and electrically non-conductive. A clamping mechanism of a metallic material allows the absorption of larger mechanical forces due to a change in volume, so that the deformation of the battery cells can be reliably counteracted. Metallic materials are particularly resistant to mechanical and chemical influences, so that a corresponding propagation protection of the clamping mechanism and / or the module wall can be ensured over the entire life of the battery module. Both in the clamping mechanism and / or the Modulwandung metallic materials such. As steel (unalloyed, low alloyed or high alloyed) or aluminum are used. The use of steel is particularly inexpensive and easy to produce, with aluminum being particularly light.

In the context of the invention, the module wall may be at least partially rigid and / or inflexible. If the module wall is at least partially rigid and / or inflexible, then the forces from the clamping mechanism to the module wall can be transmitted in the best possible way. Consequently, the forces due to the volume expansion are transmitted almost directly to the tensioning mechanism or transferred from the tensioning mechanism to the module wall, so that the mechanical influence is limited to the Modulwandung in such a way that the individual battery cells are limited in their volume expansion. Particularly preferably, it can be achieved by a partially rigid and / or inflexible module wall that a controlled volume expansion of the battery cell and thus of the battery module can be achieved. It can be influenced at which point of the module wall a volume change can be achieved at least tlw. So it is z. B. conceivable that the module wall in places at least tlw. Is rigid and / or inflexible, where in particular the clamping mechanism is in contact with the module wall, so that the forces of the clamping mechanism can be transmitted directly to the module wall. Thus, it is achieved that the module wall is not disadvantageously deformed by the force of the clamping mechanism, so that capacity losses or destruction of the module walls can be prevented.

It is also conceivable that the module wall is designed in several parts, in particular that the module wall is at least partially interleaved. A multi-part design of the module wall can, for. B. be designed so that differently shaped geometries of the module wall and / or different materials of the module wall are connected to each other, so that less-stressed parts of the module wall smaller dimensioned components are used and at more stressed areas larger components are arranged. Particularly preferably, the components of the module wall are designed to be movable relative to one another, so that, on the one hand, a simple assembly or disassembly as well as a movement relative to one another can be achieved. Thus, the different components of the module wall, for example, be nested, so that at least two components of the module wall on at least two sides of the battery module, for example, the end faces of the battery module, are designed to be slidable. Accordingly, at least two parts of the module wall can be configured in such a way that each part surrounds at least two sides of the battery module and they are geometrically configured such that they can be nested so that a drawer-like configuration of the module wall results. In this case, the module wall, the battery cells in full or full surface or only partially surrounded. If the battery cells are completely surrounded by the module wall, then the battery cell can be thermally coupled so that little heat energy is lost. If the battery cells are only partially surrounded by the module wall, then a simple cooling of the battery cells can be achieved by the fluid surrounding the battery cells. Advantageously, a part of the module wall can have a bearing, in particular a roller and / or slide bearing, so that the at least one module wall is mounted so as to be movable on a surface with low friction.

In the context of the invention, the battery cell may be a prismatic cell or a cylindrical cell or a bag cell. The Modulwandung is to the respective geometric shape of the Battery cell adapted. Accordingly, the clamping mechanism is designed such that a volume change of a prismatic cell, a cylindrical cell or a bag cell, the best possible mechanical counteracts. Thus, it is conceivable that in a cylindrical cell, the clamping mechanism, the cylindrical battery cell tlw. Or fully surrounds, so that a volume expansion of the cylindrical battery cell, especially at the points with the largest volume expansion is limited. Similarly, a prismatic cell can be limited by a tensioning mechanism according to the invention, in particular in the longitudinal direction.

According to a further aspect of the invention, a battery is claimed with at least one battery module according to the invention. In this case, the battery according to the invention has at least one battery module according to the invention with at least one battery cell, wherein in the battery according to the invention all the advantages which have already been mentioned in connection with the battery module according to the invention result. In this case, the inventive clamping mechanism, in addition, also the plurality of modules arranged in the battery at least partially surrounded, so that the clamping mechanism mechanically counteracts the deformation of the battery modules within the battery.

The following figures are merely descriptive and are not intended to limit the invention in any way. They show schematically:

1 a battery module according to the invention with a first embodiment of the clamping mechanism according to the invention and

2 a battery module according to the invention with a second embodiment of the clamping mechanism according to the invention.

Further, measures improving the invention will become apparent from the following description of some embodiments of the invention, which are shown schematically in the figures. All of the claims, the description or the description resulting features and / or advantages, including design details and spatial arrangements may be essential to the invention both in itself and in various combinations. It should be noted that the figures have only descriptive character and are not intended to limit the invention in any way.

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

In 1 is a battery module according to the invention 100 shown with a plurality of battery cells 110 and a module wall disposed on two sides of the battery module 120 , At the module wall 120 is a clamping mechanism in the embodiment shown 130 arranged, the clamping mechanism 130 as a telescopic rail 130 with a length limit 140 is trained. In 1 is the clamping mechanism 130 at an upper portion of the battery module 100 and at a lower portion of the battery module 100 arranged so that each one clamping mechanism 130 in the form of telescopic rails 130 with a length limit 140 , on the areas of the battery cells shown 110 mechanically counteracts. In addition, on the one module wall 120 of the battery module 100 a camp 150 arranged so that a movement of the module wall 120 through the camp 150 is prevented. At the second module wall 120 , which compared with the with the camp 150 connected module wall 120 is arranged by a movable bearing 150 stored in such a way that the clamping mechanism 130 by the telescopic rail-like configuration, the deformation of the battery cell allows. It is on the telescopic rails 130 arranged a slot in which the Längenbegrenzung 140 is arranged such that only along the geometric configuration of the elongated hole of the clamping mechanism 130 a movement of the battery module 100 is possible. Accordingly, the part of the battery module moves 100 in the direction of the floating bearing 150 , where at the same time the part of the battery module 100 which at the camp 150 is held in its position. Accordingly, the battery module deforms 100 only in the direction of the floating bearing 150 and is by the length limit 140 the telescopic rail 130 Limited on reaching the final position.

The 2 shows a battery module according to the invention 100 with a clamping mechanism according to the invention 130 in a further embodiment, wherein the clamping mechanism 130 with a spring 131 spring loaded. The two module walls 120 of the battery module 100 are doing by the clamping mechanism 130 connected to each other, wherein on the clamping mechanism 130 the feather 131 is arranged, and a change in length is made possible by the spring. The battery module 100 is on the camp 150 movably mounted, so that a deformation of the battery cell 110 due to a volume change is made possible at least in parts. At the camp 150 is also a length limit 140 arranged, showing the movement of the battery module 100 limited to two sides. Accordingly, that is battery module 100 so with the camp 150 connected to that module wall 120 only between the two length limits 140 is movable. The Längenbegrenzung serves accordingly in addition to the spring 131 the clamping mechanism 130 in addition, a deformation of the battery cell 110 counteract mechanically. The warehouse 150 is in 2 as a ball bearing 150 designed so that the Modulwandung 120 ball-bearing and movable on the ground on which the battery module 110 is arranged, stored and by the length limitation 140 is limited in its extent.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009052508 A1 [0003]

Claims (10)

Battery module ( 100 ) comprising at least one battery cell ( 110 ) and at least one module wall ( 120 ), the battery cell ( 110 ) at least partly from the module wall ( 120 ) is surrounded and the Modulwandung ( 120 ) in operative connection with at least one clamping mechanism ( 130 ), so that upon deformation of the battery cell ( 110 ) as a result of a volume change, the tensioning mechanism ( 130 ) the deformation of the battery cell ( 110 ) counteracts mechanically. Battery module ( 100 ) according to claim 1, characterized in that the clamping mechanism ( 130 ) is variable in length and / or a length limitation ( 140 ) having. Battery module ( 100 ) according to claim 1 or 2, characterized in that the module wall ( 120 ) and / or the clamping mechanism ( 130 ) is spring loaded. Battery module ( 100 ) according to one of the preceding claims, characterized in that the clamping mechanism ( 130 ) has at least one cylinder and / or a shock absorber and / or a telescopic rail. Battery module ( 100 ) according to one of the preceding claims, characterized in that the clamping mechanism ( 130 ) is self-locking. Battery module ( 100 ) according to one of the preceding claims, characterized in that the clamping mechanism ( 130 ) and / or the module wall ( 120 ) comprises a plastic and / or a metallic material. Battery module ( 100 ) according to one of the preceding claims, characterized in that the module wall ( 120 ) is at least partly rigid and / or inflexible. Battery module ( 100 ) according to one of the preceding claims, characterized in that the module wall ( 120 ) is formed in several parts, in particular that the Modulwandung ( 120 ) is nestable at least in sections. Battery module ( 100 ) according to one of the preceding claims, characterized in that the battery cell ( 110 ) a prismatic cell ( 110 ) or a cylindrical cell ( 110 ) or a bag cell ( 110 ). Battery ( 200 ) with at least one battery module ( 100 ) according to any one of the preceding claims.

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