Technical field

[0001] The present disclosure relates generally to a fuel cell power module and an electric vehicle comprising one or more such fuel cell power modules.

Background

[0002] The increased awareness of the environmental impact of vehicles powered by fossil fuels is paving the way for new zero emission propulsion systems. Some such new propulsion systems are based on pure battery electric solutions while other rely on hydrogen to shift the result of vehicle energy usage from CO2 emissions, to harmless H2O emissions, i.e. water exhausts.

[0003] Pure battery electric vehicles tend to suffer from reduced performance as the ambient temperature drops and is usually severely degrade when ambient temperatures fall below 5 degrees Celsius (approximately 41 degrees Fahrenheit), whereas fuel cells can continue to operate even in reduced temperatures, as fuel cells will provide sufficient heat to heat themselves during operation.

[0004] Hydrogen powered vehicles are usually equipped with a tank that feeds a fuel cell system, which fuel cell system converts the hydrogen into electricity. This electricity in turn drives an electric motor that propels the vehicle.

[0005] For large vehicles, such as passenger cars, this technology is well advanced. However, current propulsion systems of the kind used therefore normally rely on a combination of fuel cell systems having costly and bulky units comprising large stacks of bipolar plates and separated therefrom a large reinforced pressurized tank.

[0006] Thus, hydrogen propulsion based on such technology is not currently an option for small vehicles such as electric bicycles, scooters, and motorcycles, due to the incompatibility thereof with cost, weight, and space requirements of such vehicles. [0007] There is therefore a need in the art for new and improved ways of providing fuel cell power arrangements, directed at addressing at least some of the current drawbacks of prior art fuel cell power arrangements.

Summary

[0008] An object of the present invention is to provide an improved fuel cell power module.

[0009] According to a first aspect this is provided through a fuel cell power module comprising: a fuel supply module having an outer delimiting surface; a plurality of thin plate shaped micro fuel cell modules; a manifold module; and a control module, wherein the plurality of thin plate shaped micro fuel cell modules are arranged at least partially covering the outer delimiting surface of the fuel supply module and parallel to that surface and at or slightly separated therefrom to form an air flow channel along that surface, and the manifold module is arranged for distribution of fuel from the fuel supply module to the thin plate shaped micro fuel cell modules under control of the control module.

[0010] The above fuel cell power module allows for compact modules, only slightly larger than associated fuel supply modules, reduced their power/weight cost ratio as compared to pure battery electric solutions, and the above fuel cell power module also has excellent low ambient temperature operability.

[0011] In some embodiment herein the fuel supply module is a pressurized gas tank.

[0012] In other embodiments the fuel supply module is a hydrogen generator arranged to produce hydrogen gas through contact between a solid chemical hydride and a liquid reagent.

[0013] In some of these embodiments the outer delimiting surface of the fuel supply module is elongated-cylindrical or spherical. [0014] In yet some of those embodiments each thin plate shaped micro fuel cell module comprises one or more series of six micro fuel cells and an associated sensor cell for monitoring operational parameters thereof.

[0015] In yet some further embodiments the fuel cells in each thin plate shaped micro fuel cell module are open cathode fuel cells.

[0016] In still further embodiments the fuel distribution manifold module comprises valves, regulators and channeling for controlled distribution of fuel from the fuel supply module to the thin plate shaped micro fuel cell modules.

[0017] In yet some embodiments the fuel distribution manifold module is arranged as an extension of the fuel supply module outer delimiting surface.

[0018] In some yet further embodiments, the fuel cell power module further comprises a rechargeable electricity storage module arranged to cooperate with the fuel cell modules under supervision by the control module.

[0019] In some further embodiments thermal management to maintain the temperature of the fuel cell modules within a desired operating range thereof is enabled by the fuel cell modules being arranged such that natural convection of ambient air is allowed over at least one side surface of the fuel cell modules facing either away from or towards the fuel supply module outer delimiting surface.

[0020] In other embodiments the control module further comprises a thermal management system arranged to control the temperature of at least one of the fuel cell modules, the rechargeable electricity storage module, and the fuel supply module to within their respective desired operating ranges in response to ambient temperature conditions.

[0021] In some additional embodiments the thermal management system further is arranged to control the temperature through selectively applying an electric fan induced airflow for causing forced convection of ambient air over at least one side surface of the fuel cell modules facing either away from or towards the fuel supply module outer delimiting surface. [0022] In still some of the embodiments that comprises a thermal management system the thermal management system is further arranged to distribute heat from the fuel cell modules to effect heating of the fuel supply module under lower ambient temperature conditions and to effect cooling of the fuel supply module under higher ambient temperature conditions through applying an electric fan induced airflow through the air flow channel along the fuel supply module outer delimiting surface for causing forced convection of ambient air over that surface.

[0023] In some further embodiments the fuel cell power module further comprises a cover at least partially enclosing the modules thereof, the cover having one or more ventilation openings for enabling flow of ambient air into and out of the cover.

[0024] It is a further object of the present invention to provide an electric vehicle comprising one or more fuel cell power modules of the herein disclosed type.

[0025] Some of the above embodiments have the beneficial effect of allowing for passive thermal management by natural convection of ambient air.

[0026] Besides allowing for passive thermal management, other embodiments allow for active thermal management of the fuel cells, the rechargeable electricity storage module, as well as of the fuel supply module.

[0027] Furthermore, at least some of the above embodiments facilitates start-up of the power module, as a rechargeable electricity storage module can be used to ensure power for the control module during start-up of operation of the fuel cells thereof.

Brief description of drawings

[0028] In the following, embodiments herein will be described in greater detail by way of example only with reference to attached drawings, in which:

[0029] Fig. 1 a illustrates schematically a section through a first embodiment fuel cell power module having fuel cell modules arranged at the outer delimiting surface of the fuel supply module. [0030] Fig. 1 b illustrates schematically a section through a second embodiment fuel cell power module having fuel cell modules arranged slightly separated from the outer delimiting surface of the fuel supply module.

[0031] Fig. 2 illustrates schematically a thin plate shaped micro fuel cell module that comprises two series of six micro fuel cells each series with a respective associated sensor cell for monitoring operational parameters thereof.

[0032] Fig. 3a illustrates schematically a setup for active thermal management of the first embodiment fuel cell power module utilising a fan.

[0033] Fig. 3b illustrates schematically a setup for active thermal management of the second embodiment fuel cell power module utilising a fan.

[0034] Fig. 4a illustrates schematically a hybrid fuel cell power module based on the first embodiment fuel cell power module comprising a rechargeable electricity storage module and setup for passive thermal management.

[0035] Fig. 4b illustrates schematically a hybrid fuel cell power module based on the second embodiment fuel cell power module comprising a rechargeable electricity storage module and setup for passive thermal management.

[0036] Fig. 4c illustrates schematically a hybrid fuel cell power module based on the first embodiment fuel cell power module comprising a rechargeable electricity storage module and setup for active thermal management.

[0037] Fig. 4d illustrates schematically a hybrid fuel cell power module based on the second embodiment fuel cell power module comprising a rechargeable electricity storage module and setup for active thermal management.

[0038] Fig. 5a illustrates schematically a bicycle having an electric assist motor and a fuel cell module according to embodiments herein arranged at a down tube thereof and a cover therefor removed.

[0039] Fig. 5b illustrates schematically the bicycle according to figure 5a with a cover for the fuel cell module applied. Description of embodiments

[0040] In the following will be described some example embodiments of an improved fuel cell power module 1.

[0041] The herein described fuel cell power module 1 is based on the realization that where some prior-art fuel cell systems can be very bulky the use of small, flat and shapeable fuel cells, i.e. micro fuel cells, such as single Proton Exchange Membrane (PEM) fuel cells with an open-end design, such as applicants myFC LAMINA™ fuel cells, gives an improved freedom of geometrical design and distributed placement for the components of the fuel cell power module 1 described herein.

[0042] The myFC LAMINA™ fuel cells referenced above use hydrogen gas and transform it into clean electrical power. Since the myFC LAMINA™ fuel cell design also can use passive air feed and comprise no conventional bi-polar plates, it provides cost advantages and requires a less complicated manufacturing process, as compared to fuel cells comprising conventional bi-polar plates. Thus, using thin, formable, high power density, and low-cost mass producible myFC LAMINA™ fuel cells with an open-ended hydrogen system for the fuel cell power module 1 described herein allows for scalable flexibility in configuring and tailoring fuel cell power modules to a multitude of differing applications, such as applications suitable for small vehicles, such as electric scooters and motorcycles and also for unmanned aerial vehicles (UAVs), commonly known as drones.

[0043] However, although suitable for small vehicle applications, the herein proposed fuel cell power module may also be used for other applications, such as larger vehicles or other equipment relying on electrical power.

[0044] Thus, according to a first aspect is proposed a fuel cell power module, sections of which are illustrated in figures 1 a or 1 b, suitable for such use. The fuel cell power module 1 comprises a fuel supply module 2 having an outer delimiting surface, which outer delimiting surface in different embodiments may e.g. be elongated-cylindrical or spherical. [0045] In some embodiments the fuel supply module 2 is a pressurized gas tank, and in other, alternative embodiments, the fuel supply module is a hydrogen generator, arranged to produce hydrogen gas through contact between a solid chemical hydride and a liquid reagent.

[0046] Thus, the outer delimiting surface may be the outer surface of the pressurized gas tank or that of the hydrogen generator, e.g. a metal hydride canister.

[0047] In case of the fuel supply module 2 being a pressurized gas tank, it is preferably a cylindrical or spherical pressure vessel. A cylindrical pressure vessel for use with hydrogen will usually have hemispherical heads at each end of its cylindrical body, although other head shapes are also feasible, such as ellipsoidal or torispherical.

[0048] The fuel cell power module 1 further comprises a plurality of thin plate shaped micro fuel cell modules 3.

[0049] The fuel cells 3a in each thin plate shaped micro fuel cell module 3 are suitably open cathode fuel cells.

[0050] In some embodiments each thin plate shaped micro fuel cell module 3 comprises one or more series of six micro fuel cells 3a and for each series an associated sensor cell 4 for monitoring operational parameters thereof. In one embodiment, as illustrated in figure 2, each thin plate shaped micro fuel cell module 3 comprises two series of six micro fuel cells 3a, each series with a respective associated sensor cell 4.

[0051] The serial connection of six fuel cells 3a is used to increase the voltage output in order to enable drawing the proper power out of the fuel cells 3a, which is suitably done via a DC-DC converter (not shown).

[0052] In any DC-DC converter design it is vital to, whilst reaching the control targets, still retain a high efficiency. A DC-DC converter generally has greater losses at high currents and at low voltage, exactly what a single fuel cell 3a produces.

[0053] A single fuel cell 3a has the theoretical working range of slightly above one volt down to zero volts, and a current proportional to the physical membrane area and the amount of hydrogen gas supplied. Thus, the low voltage of a single fuel cell 3a does not make it possible to achieve high efficiency, this since it is on par with a transistor terminal voltage. For this reason, the serial connection of six fuel cells 3a is used to increase the voltage input to the DC-DC converter and by that the efficiency thereof.

[0054] The fuel cell power module 1 further comprises a manifold module 5 and a control module 6, where the manifold module 5 is arranged for distribution of fuel from the fuel supply module 2 to the thin plate shaped micro fuel cell modules 3 under control of the control module 6.

[0055] The control module 6 may, in embodiments where the fuel supply module 2 has a bottle shaped outer delimiting surface with a neck connecting to the manifold module 5, as illustrated in figures 1 a and 1 b, have a toroidal shape arranged around the neck, in order to utilize the available space effectively for high density packaging of the fuel cell power module 1.

[0056] The fuel distribution manifold module 5 comprises valves, regulators, and channelling (not shown) for controlled distribution of fuel (hydrogen) from the fuel supply module 2 to the thin plate shaped micro fuel cell modules 3.

[0057] In order to obtain a compact and coherent fuel cell power module 1 , the fuel distribution manifold module 5 may be arranged as an extension of the fuel supply module 2 outer delimiting surface. Thus, as illustrated in figures 1 a and 1 b, in the case of an elongated-cylindrical fuel supply module 2, creating a natural cylindrical extension of the outer delimiting surface thereof.

[0058] Also, to obtain a compact and coherent fuel cell power module 1 the plurality of thin plate shaped micro fuel cell modules 3 are arranged at least partially covering the outer delimiting surface of the fuel supply module 2 and parallel to that surface and at, as illustrated in figure 1a, or slightly separated therefrom, as illustrated in figure 1b, to form an air flow channel 7 along that surface.

[0059] The plurality of thin plate shaped micro fuel cell modules 3 may in some embodiments be arranged to cover an area of 180 degrees around the cylindrical outer delimiting surface of the fuel supply module 2, and in other embodiments 360 degrees, i.e. all the way around the cylindrical outer delimiting surface of the fuel supply module 2 may be covered by the plurality of thin plate shaped micro fuel cell modules 3. Further embodiments may employ a coverage of anywhere between 1 - 360 degrees around the cylindrical outer delimiting surface of the fuel supply module 2, although for most applications it will be desirable to cover at least 180 degrees, in order to provide sufficient power from the fuel cell modules 3.

[0060] An advantage of a compact and coherent fuel cell power module 1 for generating electric motive power, e.g. for vehicles, is that vehicles of this kind may use such compact and coherent fuel cell power modules 1 , that quickly and easily may be exchanged to fresh ones.

[0061] Even if the fuel cell power module 1 is fixedly arranged, the quick refuelling capabilities thereof provides an advantage, as compared to the usually rather prolonged charging times of current pure battery electric vehicles using fixed on-board battery packs.

[0062] The fuel cell power modules 1 described herein also enables increased capacity and thus operating time/range at similar weights, sizes, and cost, as compared to their current pure battery electric counterparts, even those using replaceable battery packs.

[0063] Through arranging the plurality of thin plate shaped micro fuel cell modules 3 at least partially covering the outer delimiting surface of the fuel supply module 2 and parallel to and at that surface, as illustrated in figure 1a, a fuel cell power module 1 only slightly larger than the outer delimiting surface of the fuel supply module 2 is obtainable. [0064] Thermal management may, for the above-described fuel cell power module 1 , be effected through allowing a cooling airflow over the side of the thin plate shaped micro fuel cell modules 3 facing away from the outer delimiting surface of the fuel supply module 2.

[0065] Alternatively, the plurality of thin plate shaped micro fuel cell modules 3 may, as illustrated in figure 1 b, be arranged at least partially covering the outer delimiting surface of the fuel supply module 2 and parallel to that surface and slightly separated therefrom, suitably by 4 to 10 millimeters, to form the air flow channel 7 along that surface. In this way a fuel cell power module 1 , only slightly larger than the above fuel supply module, as illustrated in figure 1a, where the thin plate shaped micro fuel cell modules 3 are arranged at the surface, is obtainable.

In this case thermal management is achievable through allowing a cooling airflow over either side of the thin plate shaped micro fuel cell modules 3 or over both sides thereof.

[0066] In some embodiments thermal management to maintain the temperature of the thin plate shaped micro fuel cell modules 3 within a desired operating range thereof is enabled by the thin plate shaped micro fuel cell modules 3 being arranged such that natural convection of ambient air is allowed over at least one side surface of the thin plate shaped micro fuel cell modules 3 facing either away from or towards the fuel supply module 2 outer delimiting surface.

[0067] In other embodiments the control module 6 further comprises a thermal management system arranged to control the temperature of at least one of the thin plate shaped micro fuel cell modules 3, the rechargeable electricity storage module 11 , and the fuel supply module 2 to within their respective desired operating ranges in response to ambient temperature conditions.

[0068] The thermal management system may, as illustrated in figures 3a and 3b, be arranged to control the temperature through selectively applying an electric fan 8 induced airflow for causing forced convection of ambient air, as illustrated by the dashed arrows 9 either towards or away from the electric fan 8, over at least one side surface of the thin plate shaped micro fuel cell modules 3 facing either away from or towards the fuel supply module 2 outer delimiting surface.

[0069] Furthermore, in embodiments, such as those illustrated in figures 3a and 3b, that comprises a thermal management system, the thermal management system may be arranged to distribute heat from the thin plate shaped micro fuel cell modules 3 to effect heating of the fuel supply module 2 under lower ambient temperature conditions, i.e. when the ambient temperature is lower than the desired operating temperature range, and to effect cooling of the fuel supply module 2 under higher ambient temperature conditions, i.e. when the ambient temperature is higher than the desired operating temperature range. This is effected through applying an electric fan 8 induced airflow 9 through the air flow channel 7 along the fuel supply module 2 outer delimiting surface, for causing forced convection of ambient air over that surface.

[0070] Distribution of heat from the thin plate shaped micro fuel cell modules 3 to effect heating of the fuel supply module 2 may be done through reducing or cancelling the electric fan 8 induced airflow 9 for causing forced convection of ambient air over at least one side surface of the thin plate shaped micro fuel cell modules 3. Heat is then allowed to pass from the thin plate shaped micro fuel cell modules 3 either, when arranged at the outer delimiting surface, as illustrated in figure 3a, through direct contact therewith, or, when arranged slightly separated from the outer delimiting surface, as illustrated in figure 3b, through heat conducting distances 10 connecting the thin plate shaped micro fuel cell modules 3 to that surface and creating the slight, preferably 4-10 mm, separation therefrom

[0071] The fuel cell power module 1 may, as illustrated in figures 4a-4d, further comprise a rechargeable electricity storage module 11 arranged to cooperate with the thin plate shaped micro fuel cell modules 3 under supervision by the control module 6. Such a fuel cell and battery hybrid power module may e.g. use Lithium- ion batteries, such as a number of 18650 Lithium-ion batteries, or Supercapacitor batteries, such as Graphene Supercapacitor batteries, or batteries based on other technologies having similar performance. Advantages of using Supercapacitor batteries include that the weight is substantially lower and the service-life substantially longer than that of corresponding Lithium-ion batteries and the ability of Supercapacitor batteries to rapidly provide high power (currents), however at the cost of relatively low energy storage capacity in relation to their volume.

[0072] By combining fuel cells 3a with a rechargeable electricity storage module 11 , as described above, it is possible to leverage each technology’s advantages and balance out their disadvantages, offering the best possible electric performance. One advantage with such a hybrid power module 1 is that start-up of the power module 1 is facilitated, as the rechargeable electricity storage module 11 can be used to ensure power for the control module 6 during start-up,.

[0073] Furthermore, in embodiments, such as those illustrated in figures 4c and 4d, that comprises a thermal management system, the thermal management system may be arranged to distribute heat from the thin plate shaped micro fuel cell modules 3 to effect heating of at least one of the fuel supply module 2 and the rechargeable electricity storage module 11 under lower ambient temperature conditions, i.e. when the ambient temperature is lower than the desired operating temperature range, and to effect cooling of at least one the fuel supply module 2 and the rechargeable electricity storage module 11 under higher ambient temperature conditions, i.e. when the ambient temperature is higher than the desired operating temperature range.

[0074] Heating and cooling of the fuel supply module 2 is effected through applying an electric fan 8 induced airflow 9 along the fuel supply module 2 outer delimiting surface, for causing forced convection of ambient air over that surface.

[0075] Heating and cooling of the rechargeable electricity storage module 11 is effected through applying the electric fan 8 induced airflow 9 either in a direction to transport heat from the fuel cells 3a to the rechargeable electricity storage module 11 or to draw heat from the rechargeable electricity storage module 11 through applying the electric fan 8 induced airflow 9 in a direction to transport heat therefrom. [0076] This kind of hybrid power modules 1 will be suitable as range extenders for battery-powered electric vehicles, where a pure battery module may be exchanged for a hybrid power module 1 of this kind and provide for an increased vehicle range.

[0077] Similarly, it could also significantly extend the flight time of large drones, which would be able to fly for significantly longer periods of time than what is currently obtainable.

[0078] They will also be suitable for various warehousing logistics machinery, such as e.g. forklifts, pallet jacks, stackers, order pickers, and reach trucks, whether human operated or autonomous, and could be particularly advantageous for use in cold-storage facilities due to the ability of fuel cells to provide heat to support their own operation during that operation.

[0079] Furthermore, as power modules 1 of the kind described herein, pure fuel cell or hybrid, are possible to refuel in approximately 1-2 minutes, it would be possible to provide an uptime in warehousing applications exceeding 99%, as compared with an uptime of approximately 92-94% of their pure battery electric counterparts due to the charge-time requirements thereof.

[0080] In some further embodiments the fuel cell power module 1 further comprises a cover 12, one example of which is illustrated in figure 5b, at least partially enclosing the modules thereof, the cover 12 having one or more ventilation openings 12a, 12b for enabling flow of ambient air into and out of the cover 12.

[0081 ] The cover 12 may, in cases where it does not completely enclose the fuel cell power module 1 , e.g. as illustrated in figure 5b, be arranged to co-operate with a receiving structure at a vehicle 13 or other equipment to be powered thereby, such that complete enclosure is achieved when the fuel cell power module 1 is attached thereto.

[0082] The cover 12 may e.g. comprise one or more air-intake openings 12a, for introducing ambient air into the cover 12 and one or more air-outlet openings 12b, for expelling air from the cover 12. As described above, air flows may be driven by natural convection or using one or more electric fans 8.

[0083] Also envisaged herein is an electric vehicle 13 comprising one or more of the herein disclosed fuel cell power modules 1.

[0084] An example of such a vehiclel 3 is, as illustrated in figures 5a and 5b, a bicycle having an electric assist motor. As shown, the fuel cell power module 1 may be arranged to be received along the down frame 13a of the bicycle 13, which is particularly advantageous as only a natural convection flow of air may be sufficient for thermal management, i.e. cooling, of the fuel cell power module 1 , thus eliminating the need of means, such as a fan 8, for producing a forced air flow, thus reducing cost, weight, and space requirements in such applications.

[0085] Fort the application illustrated in figures 5a and 5b, the plurality of thin plate shaped micro fuel cells 3 are suitably arranged to cover approximately 180 degrees around the outer delimiting surface of an elongated-cylindrical fuel supply module 2. The fuel cell power module is then arranged at a receiving structure of the downtube 13a of the bicycle 13, such that its plurality of thin plate shaped micro fuel cells 3 faces outwards forward of the downtube.

[0086] With a cover 12 applied and the fuel cell power module 1 of the bicycle 13 arranged along the down tube 13a and the outer periphery thereof covered by the cover 12, the running wind will thus be taken into the cover 12 through the air- intake openings 12a during operation of the bicycle, causing a forced addition to the natural convection air flow.

[0087] When the vehicle 13 is stopped or traveling at a low speed, convection of air flowing from lower air-intake openings 12a to upper air-outlet openings 12b is generated in the cover 12 by the heat of the thin plate shaped micro fuel cell modules 3, and the heat is efficiently dissipated.

[0088] However, it is of course also possible to have one or more electric fans 8 for improved controllability of the thermal properties. [0089] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. In cases where advantages, benefits or solutions to problems are described herein, it should be appreciated that such advantages, benefits and/or solutions may be applicable to some example embodiments, but not necessarily all example embodiments. Thus, any advantages, benefits or solutions described herein should not be thought of as being critical, required or essential to all embodiments or to that which is claimed herein. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.