Battery module holder and related battery energy storage system

Abstract

The invention provides Battery module holder 100, 150 for use in a battery energy storage system, said battery module holder 100, 150 comprising at least one battery module 101, 151 each battery module comprising a plurality of battery cells, wherein said battery module holder 100, 150 comprises an isolating base plate 200, 250 for mounting said at least one battery module 101, 151, said isolating base plate 200, 250 being further configured for mounting said battery module holder 100, 150 in said battery energy storage system.

Description

[0001] BATTERY MODULE HOLDER AND RELATED BATTERY ENERGY STORAGE SYSTEM

[0002] Technical field

[0003] The present invention relates to a Battery module holder for use in a battery energy storage system, and a related battery energy storage system.

[0004] Background art

[0005] Often, when batteries from electric vehicles are not usable anymore in an electric vehicle because they do not meet the high requirement for use in the electric vehicle, they can still be given a useful second life to serve energy storage, which has less demanding requirements.

[0006] A battery pack of an electric vehicle typically consists of multiple individual battery modules. Even when one battery module is not usable anymore, the other battery modules can be reused without problems for stationary energy storage.

[0007] However, these battery modules are built to serve in an electric vehicle and not in an energy storage application. There is also a big variety of battery modules in electric vehicles, with different mechanical layouts and dimensions and different electrical characteristics.

[0008] Creating a different mechanical design for every different type of electric vehicle battery module is costly and not economical. Hence, there is a need for a mechanical design to make different types of battery modules from electrical vehicles ready for use in a stationary energy storage system.

[0009] Currently, plenty of battery modules designs exist as an assembly of battery cells. However, no assemblies exist which are designed for re-using existing battery modules, built for another purpose such as usage in an electric vehicle, in a racking for stationary energy storage.

[0010] Disclosure of the invention

[0011] It is an object of the present invention to provide a battery module holder for enabling the re-use of battery modules, designed for use in other applications, in a battery energy storage system. The battery module holder can accommodate battery modules having various different mechanical and electrical characteristics in an efficient manner.

[0012] It is an additional object of the present invention to provide a mechanical design which enables the re-use of a battery module from an electric vehicle in a battery module holder and related battery energy storage system in a safe manner.

[0013] Indeed this object is achieved by applying a Battery module holder according to embodiments of the present invention for use in a battery energy storage system where said battery module holder comprises at least one battery module from an electric vehicle, wherein each battery module comprises a plurality of battery cells, and wherein the storage module comprises an isolating base plate for mounting said at least one battery module on said isolating base plate wherein said isolating base plate enables the at least one battery module to be fully floating and electrically isolated from a housing of a battery energy storage system and wherein said isolating base plate being further configured for mounting said battery module holder in said battery energy storage system in an electrically isolated manner.

[0014] The isolating base plate, at first enables such a battery module to be fully floating and isolated from the housing causing that there is no connection to ground between the casing of the battery module and the ground. This is preferred because this avoids the risk of isolation breakthrough of the battery module in case of a ground fault in such a battery energy storage system. By eliminating the risk of isolation breakthrough, due to the electrical isolation of the modules, a higher DC voltage can be built up in a safe way in the energy storage system than is usual in the electric car. The higher DC voltage ensures smaller currents and a more efficient energy storage system, and allows to use single-stage DC / AC battery inverters instead of two-stage inverters have higher losses.

[0015] The battery module holder comprises at least one battery module, constructed for another application than stationary energy storage, such as a battery module designed for an electric vehicle. Such a battery module is built up of a plurality of battery cells.

[0016] In other words, the battery module that for instance powers electrified vehicles, consists of individual battery cells and modules organized in series and parallel. A cell is the smallest unit of a battery system, comprising 4 key components including cathode, anode, electrolyte and a separator. The battery module holder allows at least one battery module for instance dedicated to electric vehicles, to be mounted in such battery module holder and being housed in a battery energy storage system such as in racks for energy storage in a modular and efficient and safe manner.

[0017] The battery module(s) for mounting on an isolated base plate of the battery module holder may be a reused electrical vehicle battery module or equivalent.

[0018] Embodiments of the present invention allow efficient maintenance of the battery energy storage system. In case battery modules that are too degraded or broken such battery modules can be replaced very efficiently, easily and safely.

[0019] A further relevant embodiment of the present invention relates to a battery module holder according to claim 1 wherein said isolating base plate comprises a front plate, which is electrically isolated from the battery module and mounted on said isolated base plate, said front plate comprising touch-safe connectors for connecting to a respective positive and negative pole of said battery module(s) and for instance for coupling to the battery management system of the battery module(s) or other functional elements of such battery energy storage system.

[0020] Advantageously, said front plate which is mounted on said isolated base plate, comprises connectors for connecting to the poles of said battery module which hides the exposure of live parts to the user in this manner preventing such a user to be able to touch high voltage carrying elements.

[0021] This construction prevents live contacts from being directly exposed to the user and makes everything touch-safe.

[0022] Another relevant embodiment of the present invention is that a battery module holder according to claim 2, wherein in case of a plurality of battery modules, said battery modules of said plurality of battery modules are coupled in series using wiring or busbars.

[0023] A still further relevant embodiment of the present invention is that the battery module holder according to claim 2 or claim 3, wherein said front plate additionally comprises a communication connector for coupling to a battery protection unit said battery energy storage system.

[0024] In this manner such a battery module can be directly coupled to a battery protection unit for protecting each battery module included in such battery management system. Still another embodiment of the present invention relates to a battery module holder according to any of claims 1 to 4, wherein in case of a plurality of battery modules the battery modules are interconnected with bolts and a metal plate for attaching said battery modules of said plurality of battery modules to the isolating base plate.

[0025] Another relevant embodiment of the present invention relates to a Battery module holder according to any of claims 1 to 5, wherein each battery module of said at least one battery module is mounted on said isolating base plate by means of at least one bolt, said at least one bolt being countersunk in said isolating base plate.

[0026] By countersinking said at least one bolt, the battery module is mounted in a manner preventing the bolts used to mount the battery module on the isolated plate, to break the isolation by making direct contact between the bolts and the housing or the ground of the energy storage system.

[0027] A further advantageous embodiment of the present invention relates to a battery module holder according to any of claims 1 to 6, wherein said isolated base comprises an integrated handle at the front portion of said isolated base plate which handle extends on the outer side of front plate of said battery holding module.

[0028] By modelling at design of the isolating base plate, the isolating base plate in such a manner that this base plate additionally comprises this handle and at production of such isolated base plate this handle in one single action can be shaped forming part of the same isolated based plate material without an additional effort which would be needed when mounting a separate and distinct handle at such battery module holder. This integrated handle, hence forming part of said the isolating base plate furthermore is providing with a safe, isolated grip of said battery module.

[0029] Another relevant embodiment of the present invention relates to a Battery module holder according to any of claims 1 to 7, wherein said isolating base plate comprises at least one hole for fixing the cables connecting one or multiple battery poles with the connectors in the front plate in place.

[0030] Still another relevant embodiment of the present invention relates to a Battery energy storage system for storing at least one Battery module holder for energy storage. Another relevant embodiment of the present invention relates to a Battery energy storage system wherein said Battery energy storage system comprises at least on battery module holder according to any of the claims 1 to 8, being assembled in a rack.

[0031] By applying standard storage systems such as rack systems, like 19-inch rack systems, design costs are reduced, the meant battery storage systems allow series production, and the cost of adapting to different types of battery modules for use in such battery energy storage system is minimal. The design therefore facilitates to apply battery modules with various different mechanical and electrical characteristics in an efficient manner and additionally enables to re-use battery modules designed for use in an electric vehicle, for use in an energy storage system in a safe manner.

[0032] A further relevant embodiment of the present invention relates to a battery energy storage system according to claim 9 wherein said rack system comprises a pair of L-profiles configured to support each of said at least one battery module holder.

[0033] The battery energy storage system such a rack comprises a pair of L- profiles configured to support each of said at least one battery module holder.

[0034] Such pair of L-profiles are configured to support each of said at least one battery module holder for mounting a battery module holder in a very efficient, easy and safe manner.

[0035] Brief description of the drawinas

[0036] The invention will be further elucidated by means of the following description and the appended figures.

[0037] Figure 1 represents a battery module holder according to an embodiment of the present invention wherein a single battery module is accommodated; and

[0038] Figure 2 represents a battery module holder according to an embodiment of the present invention wherein a plurality of battery modules is accommodated; and

[0039] Figure 3 represents a battery module holder according to an embodiment of the present invention: top view; and Figure 4 represents a battery module holder according to an embodiment of the present invention: front view; and

[0040] Figure 5 represents a top view of the isolating base plate; and

[0041] Figure 6 represents a battery module holder according to an embodiment of the present invention: side and cross section view; and

[0042] Figure 7 represents a battery module holder according to an embodiment of the present invention wherein a plurality of battery modules is accommodated: top view and

[0043] Figure 8 represents a battery module holder according to an embodiment of the present invention wherein a plurality of battery modules is accommodated: side and cross section view;

[0044] Figure 9 represents a battery string for use in a battery energy storage system, comprising a plurality of battery module holders assembled in a rack according to an embodiment of the present invention.

[0045] Modes for carrying out embodiments of the present invention

[0046] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.

[0047] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.

[0048] Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein. The term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0049] The above and other objects and features of the invention will become more apparent and the invention itself will be best understood by referring to the following description of an embodiment taken in conjunction with the accompanying drawings.

[0050] In the following paragraphs, referring to the drawing in FIG.1 an implementation of a battery module holder according to the present invention is described wherein the battery module holder houses a single battery module.

[0051] In the second paragraph, all connections between mentioned elements are defined.

[0052] Subsequently all relevant functional means of the mentioned system as presented in FIG.1 are described followed by a description of all interconnections. In the succeeding paragraph the actual execution of the system is described.

[0053] Currently, if battery modules from electric vehicles are not usable anymore in the electric vehicle because they do not meet the stringent requirements for use in the electric vehicle, they can still be given a useful second life to serve as energy storage which has less demanding requirements.

[0054] A battery pack of an electric vehicle typically consists of multiple individual battery modules. Even when one battery module is not usable anymore, the other battery modules can be reused without problems for stationary energy storage.

[0055] These battery modules are built to serve in an electric vehicle instead of a stationary energy storage application.

[0056] Moreover, there is also a big variety of battery modules in electric vehicles, with different mechanical layouts and dimensions and different electrical characteristics. Creating a different mechanical design for every different type of electric vehicle battery module is hence costly and not economical. There is thus a need for a mechanical design to host and use battery modules designed for use in electric vehicles in stationary energy storage applications.

[0057] Hence there is a need for a design enabling the re-use of battery modules, which are designed for other applications such as electric vehicles, in an energy storage system which can accommodate battery modules having various different mechanical and electrical characteristics in an efficient manner.

[0058] In order to achieve the object of the present invention, a battery module holder 100, 150 is provided for enabling the re-use of battery modules, 101 , 151 , designed for use in other applications such as electric vehicles, in a related energy storage system. The battery module holder can accommodate such battery modules having various different mechanical and electrical characteristics in an efficient manner. The invention provides a battery string for use in a Battery energy storage system comprising at least one battery module holder 100, 150 for energy storage. The Battery module holders may be assembled together in a rack system 301 like a 19-inch rack system or alternatively be any other type of rack system for use in such a Battery energy storage system.

[0059] Such battery energy storage system may be coupled to the power grid for storage of electrical power.

[0060] Each battery module holder 100, 150 comprised by such rack 301 in a Battery energy storage system is coupled in series so that the system of in-series coupled battery modules reaches a designated output voltage depending on the voltage requirements of the coupled appliance. Such an appliance may be a DC / AC inverter to couple the battery system to an AC grid, or a DC / DC converter to couple the battery system to a DC bus.

[0061] For instance, a standard 19” rack 301 may be applied to host the battery module holders. One single 19” rack may be configured to hold an arbitrary number of battery module holders.

[0062] The respective battery module holders are identical and can be connected in series. The battery module holders 100, 150 are designed so that there are no live parts directly exposed to the user approaching the rack from the front side.

[0063] The Battery module holder 100, 150 for use in the battery energy storage system 300 comprises at least one battery module 101 ,151 , for instance a battery module designed for or originating from an electric vehicle such as a car, an electric truck or an electric boat. Each said battery module comprises a plurality of battery cells.

[0064] The battery module holder 100,150 comprises an isolating base plate 200, 250 that is configured for mounting said at least one battery module 101 , 151 on top of said isolating base plate 200, 250 wherein said isolating base plate enables the at least one battery module housing to be fully floating and electrically isolated from a housing or a rack 301 of the battery energy storage system and of the housing of the other battery module in the battery energy storage system.

[0065] This is preferred because this avoids the risk of isolation breakthrough of the battery module housing in case of a ground fault in such a battery energy storage system. This allows to build up a higher DC voltage in a safe way in the energy storage system than is usual in the battery pack hosting the battery modules in its first application, as the isolation resistance between the battery module poles and the battery module housing is typically designed only to hold the DC voltage of the battery pack in the original application.

[0066] The higher DC voltage in the energy storage system ensures smaller currents and a more efficient energy storage system, and allows to use single- stage DC / AC battery inverters instead of two-stage inverters, which are less efficient due to their use of two-stage inverters.

[0067] It is further to be noted that such a battery module 101 , 151 is built up of a plurality of battery cells. In other words, the battery module 101 , 151 that for instance powers electrified vehicles, consists of individual battery cells and modules organized in series and parallel. A cell is the smallest unit of a battery, comprised of 4 key components including cathode, anode, electrolyte and separator.

[0068] The battery module holder 100, 150 allows at least one battery module 101 , 151 for instance dedicated for electric vehicles, to be mounted in such battery module holder and being housed in a battery energy storage system 300 such as in racks for energy storage in a modular and efficient way.

[0069] The battery module(s) for mounting on such isolated base plate of the battery module holder may be a reused battery module from an electric vehicle, such as an electric car, bus or boat, or equivalent.

[0070] Finally, embodiments of the present invention enable the efficient maintenance of the battery energy storage system and easy replacement of defective battery modules. In case battery modules are too degraded or broken such battery modules can be replaced very efficiently, easily and safely, by disconnecting the cables 302 from the battery module holder DC connectors 107, which are touch-safe, preventing the risk on electrical shock or touching a live battery pole, and sliding out the entire battery module holder 100,150 with battery module(s) 101 ,151 , over on the L-profiles 303 in a racking 301 , while using the front handle 201. A new, similar battery module holder can then be slid into the racking 301 over the L-profiles 303, using the front handle 201 and then connecting the DC cables 302 back to the DC connectors 107.

[0071] Figure 1 displays a battery module holder 100 comprising a single battery module 101 while Figure. 2 shows a battery module holder 150 comprising a plurality of battery modules 151 , in particular three smaller battery modules 151 in this figure.

[0072] Figure 3 shows the top view of the embodiment of Figure 1 while Figure 4 shows the side view. In this embodiment wherein the battery module holder 100 comprises one battery module 150, one battery pole of the battery module is connected via a wiring 104 to the DC connector 107 on the front plate 102, while the other battery pole of the battery module is connected via a busbar 109 to the DC connector 107 on the front plate 102. The wiring 104 itself is connected using a cable shoe 109 to the battery module and fixed in place using cable holders 105, which are fixed in pre-drilled holes 203 of the isolating base plate 200. The battery module 101 is fixed on pre-drilled holes 202 in the isolating base place 200 using bolts 21 1 and nuts 106. To not break the electric isolation of the battery module housing to the rack 301 via the bolts 21 1 and nuts 106 and the L-profiles 303, the pre-drilled holes 202 have a countersunk opening 210.

[0073] Figure 2 shows an embodiment wherein the battery module holder comprises three battery modules 151. Figure 7 shows the top view of this embodiment, while Figure 8 shows the side view of this embodiment. The poles of the battery modules are connected in series using internal connections 152, which could be a busbar or a wiring. The positive and negative poles of the in-series connected battery modules are then connected to the DC connectors 107 on the front-plate 102 of the battery module holder with a wiring 154. The wiring is again fixed on the isolating base plate 250 using wiring fixings 105 fixed in pre-drilled holes 203. The battery modules 151 are fixed on pre-drilled holes 210 on the isolating base plate 150 using bolts 212 and nuts 156.

[0074] In a further advantageous embodiment, the pre-drilled holes 202 in the isolating base plate 150 have a countersunk opening to countersink the bolts 21 1 , 212. This, to not break the electric isolation of the battery module housing to the rack 301 via the bolts 21 1 , 212 and nuts 106, 156 to the L-profiles 303. The countersunk holes make that the bolts 211 , 212 will never touch the L-profiles 303 and keep a safe isolation distance to maintain electrical isolation.

[0075] Even more advantageous is that such pre-drilled holes 202 in the isolating base plate 150 comprise a bolt thread for immediately fixing the battery module at the isolated base plate with bolts and without the need of a nut.

[0076] In an advantageous embodiment of the battery module holder 150 for using multiple battery modules 151 , the bolts 156 can be interconnected with a metal connection plate 153 for additional stability between the battery modules 151 . This may be necessary in case the busbars or wiring 152 prevents to bolt the battery modules 151 directly on the isolating base plate 250.

[0077] The Battery Module Holder 100, 150, comprises a front plate 102 which is the same front plate independent of the type of battery module 101 or multiple battery modules 151 mounted in the Battery Module Holder. This is advantageous as this means no redesign is needed in case of different battery modules. This front plate 102 comprises DC connectors 107, typically one DC connector 107 for the positive pole of the assembly of battery modules 101 , 151 , and one DC connector 107 for the negative pole of the assembly of battery modules 101 , 151 comprised in the Battery Module Holder 100, 150. Together with the front plate 102, these DC connectors 107 are hiding the exposure of live parts to the user preventing such a user to be able to touch live voltage carrying elements. This is an advantage compared to using the battery module 101 , 151 itself as on the battery module the live parts, the battery module DC poles are exposed to any user. It prevents the user from a risk on electric shock, even when putting the modules in series to build up a higher DC voltage, for which the risk on dangerous electric shocks is even more prominent.

[0078] Advantageously, these DC connectors 107 allow to make easy, tool-less connections between Battery Module Holders. For instance, in the rack 301 , the DC connectors 107 on the front plates 102 of the Battery Module Holders 100, 150, are connected in series using wiring 302. This is in contrast with wiring directly on the battery modules 101 , 151 , where the wires need to be connected using bolts, hence tool-less connections are not possible.

[0079] Being able to make and break easy, tool-less connections between battery modules 101 , 151 , which are on top not exposing the user to live parts, makes for a safer and easier assembly of the battery modules in a racking 300 for use in Battery Energy Storage System, and for easier and safer on-site maintenance and replacement of battery modules in a racking 300.

[0080] A still further relevant embodiment of the present invention is that said front plate 102 of the battery module holder 100, 150 additionally comprises a communication connection 108 for coupling a local Battery Management Unit comprised in the battery module 101 , 151 or in the Battery Module Holder 100,

[0081] 150, to a master Battery Management System, part of the Battery Energy Storage System. This communication connection 108 makes for easy, tool-less communication connections 304 between the local-Battery Management Systems on battery modules 101 , 151 or in the Battery Module Holders 100, 150 and a master Batter Management System. This is advantageous compared to connecting the communication wiring 304 directly on the battery modules 101 ,

[0082] 151 , as this typically requires specific tooling. Being able to make tool-less communication connections allows for easier assembly and enables efficient onsite maintenance and replacement of battery modules in a racking 300.

[0083] A further advantageous embodiment of the present invention relates to a Battery module holder 100, 150 wherein said isolated base 200, 250 comprises an integrated handle 201 at the front portion of said isolated base plate 200 which handle extends on the outer side of front plate of said battery holding module.

[0084] By modeling at production of the isolating base plate in such a manner that the based plate additionally comprises this handle 201 at production of such isolated base plate this handle in one same action can be shaped without an additional effort which would be required when mounting a separate and distinct handle at such battery module holder. This integrated handle 201 , hence forming part of said the isolating base plate 200, 250 furthermore is providing with a safe isolated grip of said battery module. It enables to slide a Battery Module Holder 100, 150 in and out a rack on 301 e.g. L-profiles 303 in a rack 301 , allowing for efficient assembly and replacement of battery modules in a rack 301 for use in a Battery energy storage system.

[0085] Another relevant embodiment of the present invention, as shown in Figure 9 relates to a rack 301 holding a battery string in a Battery energy storage system wherein said rack 301 comprises a pair of L-profiles 303 configured to support each of said at least one battery module holder 100, 150.

Claims

Claims1. Battery module holder (100, 150) for use in a rack (301) in a battery energy storage system, said battery module holder (100, 150) comprising at least one battery module (101, 151) , each battery module comprising a plurality of battery cells, CHARACTERISED IN THAT each said battery module being designed for use in an electric vehicle and each said battery module having predetermined mechanical and electrical characteristics, said battery module holder (100, 150) comprises an isolating base plate (200, 250) for mounting said at least one battery module (101, 151) directly onto said isolating base plate (200, 250), said isolating base plate (200, 250) being further configured for mounting said battery module holder (100, 150) in said rack (301) of a battery energy storage system.

2. Battery module holder (100, 150) according to claim 1, CHARACTERISED IN THAT said Battery module holder (100, 150) comprises a, touch-safe and pluggable, front plate (102) mounted on said isolated base plate (200, 250) said front plate comprising electrical power connectors for connecting to a respective positive and negative pole of said battery module (101).

3. Battery module holder (150) according to claim 2, CHARACTERISED IN THAT in case of a plurality of battery modules, said battery modules of said plurality of battery modules are coupled in series using wiring of busbars (152).

4. Battery module holder (100, 150) according to any of claims 2 to 3, CHARACTERISED IN THAT said front plate additionally comprises a communication connector for coupling local parts of the Battery Management System of the Battery modules (101, 151) to a master Battery Management System of said battery energy storage system.

5. Battery module holder (100, 150) according to any of claims 1 to 4, CHARACTERISED IN THAT in case of a plurality of battery modules (151) areinterconnected with bolts and metal plates (153) for attaching said plurality of battery modules (151) to said isolating base plate (250).

6. Battery module holder (100, 150) according to any of claims 1 to 5, CHARACTERISED IN THAT each battery module of said at least one battery module (101, 151) is mounted on said isolating base plate (200, 250) by means of at least one bolt, said at least one bolt being countersunk in said isolating base plate (200).

7. Battery module holder (100, 150) according to any claim 1 to 6, wherein said isolating base plate (200, 250) comprises an integrated handle (201) at the front portion of said isolated base plate (200) extending on the outer side of front plate of said battery holding module.

8. Battery module holder (100, 150) according to any claim of claims 1 to 7, wherein said isolating base plate (200) comprises at least one hole (203) for attaching the wiring (104) connecting one or multiple battery poles with the connectors in the front plate in place.

9. Battery energy storage system for using at least one Battery module holder (100, 150) for energy storage, comprising at least one Battery module holder (100) according to any of claim 1 - 8.

10. Battery energy storage system according to claim 9 wherein said Battery energy storage system comprises a rack.

11. Battery energy storage system according to claims 9 to 10 wherein said rack system comprises a pair of L-profiles (303) configured to support each of said at least one battery module holder (100, 150).

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