Rechargeable Battery Assembly for a Vehicle

Abstract

A rechargeable battery assembly for a vehicle has a metal-air rechargeable battery and a filter device to condition inlet air supplied to the metal-air rechargeable battery such that the inlet air exhibits predetermined inlet air values. The filter device has one or more filter elements, one or more sensor devices that determine at least one inlet air parameter, and one or more valve devices. A control system is coupled to the sensor devices so as to receive sensor signals for the at least one inlet air parameter and is coupled to the valve devices. The control system adjusts, depending on the received sensor signals, the valve devices in order to control the predetermined inlet air value in that the inlet air is guided through the filter elements; is guided past the filter elements; or is guided to an air outlet for regenerating the filter elements.

Claims

1. A rechargeable battery assembly for a vehicle, the rechargeable battery assembly comprising: a metal-air rechargeable battery; a filter device configured to condition inlet air supplied to the metal-air rechargeable battery such that the inlet air has predetermined inlet air values, the filter device comprising one or more filter elements, one or more sensor devices configured to determine at least one inlet air parameter, and one or more valve devices; a control system coupled to the one or more sensor devices so as to receive sensor signals corresponding to the at least one inlet air parameter and coupled to the one or more valve devices, wherein the control system is configured to adjust, depending on the received sensor signals, the one or more valve devices for controlling the predetermined inlet air values in that the inlet air: is guided through the one or more filter elements; is guided past the one or more filter elements; or is guided to an air outlet for regenerating the one or more filter elements.

2. The rechargeable battery assembly according to claim 1, wherein the predetermined inlet air values include the air humidity of the inlet air.

3. The rechargeable battery assembly according to claim 1, wherein the filter device comprises a pre-separator and/or a particle filter for separating particles from the inlet air.

4. The rechargeable battery assembly according to claim 3, wherein the one or more sensor devices include a first sensor device arranged downstream of the pre-separator and/or of the particle filter, wherein the first sensor device is configured to determine a load of the inlet air with harmful gases and/or with humidity as the at least one inlet air parameter.

5. The rechargeable battery assembly according to claim 4, wherein the one or more filter elements include a first filter element configured to remove harmful gases from the inlet air and wherein the first filter element configured to remove harmful gases from the inlet air is arranged downstream of the first sensor device.

6. The rechargeable battery assembly according to claim 5, wherein the one or more valve devices include a first valve device arranged downstream of the first sensor device, wherein the first valve device is configured to guide, depending on the at least one inlet air parameter determined by the first sensor device, the inlet air through or past the first filter element configured to remove harmful gases from the inlet air.

7. The rechargeable battery assembly according to claim 6, wherein the one or more sensor devices include a second sensor device arranged downstream of the first filter element configured to remove harmful gases from the inlet air, wherein the second sensor device is configured to determine a load of the inlet air with harmful gases and/or with humidity as the at least one inlet air parameter.

8. The rechargeable battery assembly according to claim 7, wherein the one or more filter elements include a second filter element configured to remove humidity from the inlet air and wherein the second filter element configured to remove humidity from the inlet air is arranged downstream of the second sensor device.

9. The rechargeable battery assembly according to claim 8, wherein the one or more valve devices include a second valve device arranged downstream of the second sensor device, wherein the second valve device is configured to guide, depending on the at least one inlet air parameter determined by the second sensor device, the inlet air through or past the second filter element configured to remove humidity from the inlet air.

10. The rechargeable battery assembly according to claim 9, wherein the one or more sensor devices include a third sensor device arranged downstream of the second filter element configured to remove humidity from the inlet air, wherein the third sensor device is configured to determine humidity of the inlet air as the at least one inlet air parameter.

11. The rechargeable battery assembly according to claim 10, wherein the one or more valve devices include a third valve device arranged downstream of the third sensor device, wherein the third valve device is configured to guide, depending on the humidity of the inlet air determined by the third sensor device, the inlet air to the metal-air rechargeable battery or an air outlet for regenerating the second filter element configured to remove humidity from the inlet air.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a schematic section illustration of an embodiment of a metal-air rechargeable battery in a charging state.

[0021] FIG. 2 is a schematic section illustration of the metal-air rechargeable battery according to FIG. 1 in a discharging state.

[0022] FIG. 3 is a schematic section illustration of a further embodiment of a metal-air rechargeable battery in a discharging state.

[0023] FIG. 4 is a schematic section illustration of a further embodiment of a metal-air rechargeable battery in a discharging state.

[0024] FIG. 5 is a schematic view of an embodiment of a rechargeable battery assembly.

[0025] In the Figures, same reference characters identify same or functionally the same elements as far as nothing to the contrary is indicated.

DETAILED DESCRIPTION

[0026] FIG. 1 shows a schematic section view of a metal-air rechargeable battery 1 in a charging state. FIG. 2 shows a schematic section illustration of the metal-air rechargeable battery 1 in a discharging state. The metal-air rechargeable battery 1 comprises an anode or first electrode 2 manufactured of metal, in particular of lithium Li, and a cathode or second electrode 3. In the following, only lithium-air rechargeable batteries 1 are explicitly described.

[0027] The second electrode 3 is constructed of mesoporous carbon C and is not directly participating in the electrochemical process. According to the definition of the International Union of Pure and Applied Chemistry (IUPAC), mesoporous solid bodies are porous materials with a pore diameter between 2 nm and 50 nm. Carbon C serves as an electrical conductor and connector; the mesoporous structure serves for maximizing the surface area in order to facilitate reaction of oxygen O.sub.2 with lithium ions Li.sup.+ in the area of the second electrode 3.

[0028] The first electrode 2 is comprised of a block of metallic lithium Li. Alternatively, the first electrode 2 can be comprised of a different metal, for example, silicon. Between the two electrodes 2, 3, there is an electrolyte 4 which can be liquid or solid depending on the embodiment of the lithium-air rechargeable battery 1. In the case of a solid electrolyte, a solid state rechargeable battery is provided. Moreover, the electrolyte 4 can be an organic liquid that does not react with lithium Li.

[0029] FIG. 3 shows a schematic section illustration of an embodiment of a lithium-air rechargeable battery 1 with a water-based electrolyte 4. In order to prevent a reaction of the metallic lithium Li with the electrolyte 4, between the first electrode 2 and the aqueous electrolyte 4 a protective layer 5 is provided. The protective layer 5 can be a glass-ceramic layer applied to the metallic lithium Li. For example, the protective layer 5 is a so-called LISICON layer (LiM.sub.2(PO.sub.4).sub.3). The protective layer 5 enables that the lithium Li remains stable in the aqueous environment.

[0030] FIG. 4 shows a schematic section view of an embodiment of a hybrid lithium-air rechargeable battery 1. Here, between the first electrode 2 and the protective layer 5 an organic electrolyte 4 and between the protective layer 5 and the second electrode 3 an aqueous electrolyte 4 are arranged.

[0031] The basic function principle in all types of lithium-air rechargeable batteries 1 is substantially identical. During discharge (FIGS. 2, 3, 4), an electron e.sup.− is released at the first electrode 2 and a positive lithium ion Li.sup.+ is transferred through the electrolyte 4 to the second electrode 3 where the lithium ion Li.sup.+ reacts with oxygen O.sub.2 first to lithium oxide Li.sub.2O and subsequently to lithium peroxide Li.sub.2O.sub.2. The following reduction process takes place in this context: O.sub.2+4e.sup.−.fwdarw.2 O.sup.2−. In order for this reduction process to be able to take place, the second electrode 3 is coated with a catalyst, is highly porous, and comprises therefore a very large surface area. Therefore, the second electrode 3, on the one hand, is susceptible to contamination with particles such as, for example, dust or sand, that can clog or block the second electrode 3; on the other hand, harmful gases such as sulfur oxides SO.sub.x, ammonia NH.sub.3, nitrogen oxides NO.sub.x, hydrogen sulfide H.sub.2S, carbon monoxide CO, carbon dioxide CO.sub.2 and others act as catalyst poisons that can irreversibly damage the second electrode 3. Moreover, the second electrode 3 is also moisture sensitive.

[0032] When charging (FIG. 1) the lithium-air rechargeable battery 1, this process is reversed. Oxygen O.sub.2 is released at the second electrode 3; metallic lithium Li is deposited at the first electrode 2. The first electrode 2 is moisture sensitive because the metallic lithium Li can react violently with water.

[0033] FIG. 5 shows a schematic view of an embodiment of a rechargeable battery assembly 6 with a lithium-air rechargeable battery 1 as described above. The lithium-air rechargeable battery 1 comprises a rechargeable battery control device 7 that is coupled by electrical signal lines 8, 9 to a control system 10 of the rechargeable battery assembly 6. In FIG. 5, electrical signal lines are illustrated by solid lines and air paths by dashed lines. Air paths can be, for example, pipes or channels. The air paths can be integrated in a housing of the rechargeable battery assembly 6.

[0034] The rechargeable battery assembly 6 is supplied with inlet air L. The rechargeable battery assembly 6 comprises a filter device 11 which is configured to condition the inlet air L that is supplied to the lithium-air rechargeable battery 1 in such a way that the inlet air L has a predetermined relative air humidity. The filter device 11 comprises a pre-separator 12, for example, a cyclone separator, and a particle filter 13 which is arranged downstream of the pre-separator 12. The particle filter 13 is suitable for particle filtration. This means that the particle filter 13 is configured to mechanically retain particles such as dust, pollen, sand or the like contained in the inlet air L. In this way, clogging or blocking of the mesoporous second electrode 3 is prevented. For particle filtration, the particle filter 13 can comprise a filter medium manufactured of paper and/or plastic material. Moreover, the filter medium can be coated, impregnated, and/or provided with a nanofiber layer.

[0035] Downstream of the particle filter 13, a filter element 14 is arranged that is configured to remove harmful gases from the inlet air L. In particular, the filter element 14 is configured to chemically filter harmful gases such as sulfur oxides SO.sub.x, ammonia NH.sub.3, nitrogen oxides NO.sub.x, hydrogen sulfide H.sub.2S, carbon monoxide CO, carbon dioxide CO.sub.2 from the inlet air L. These harmful gases can act as catalyst poisons that can permanently damage the catalyst provided at the second electrode 3. The filter element 14 can comprise, for example, activated carbon for chemical filtration. Moreover, the filter element 14 can comprise potassium carbonate K.sub.2CO.sub.3 and/or calcium hydroxide Ca(OH).sub.2 that chemically reacts with acidic harmful gases such as, for example, sulfur oxides SO.sub.x or hydrogen sulfide H.sub.2S in order to neutralize these harmful gases. In this way, the catalyst action is permanently maintained.

[0036] Downstream of the filter element 14, a further filter element 15 is provided that is configured to remove humidity from the inlet air L. The filter element 15 can comprise a drying agent such as, for example, silica beads. The silica beads can be sprinkled onto a filter medium of the filter element 15 and can be glued thereto. Moreover, the filter medium can be of a layer structure, wherein, for example, a layer of silica beads can be arranged between two nonwoven layers. In addition or optionally, the filter medium can comprise an absorber material, in particular a so-called superabsorber, a functionalized membrane or the like.

[0037] Between the particle filter 13 and the filter element 14, a sensor device 16 and a valve device 17 are arranged, wherein the valve device 17 is positioned downstream of the sensor device 16. The sensor device 16 is configured to determine the air quality. This means that the sensor device 16 can be configured to determine loading of the inlet air L with harmful gases. Moreover, the sensor device 16 can be configured to determine the humidity of the inlet air L. Loading of the inlet air L with harmful gases and the humidity of the inlet air L are determined as inlet air parameters. The sensor device 16 is coupled by means of the signal line 18 to the control system 10. The valve device 17 is operatively connected by means of a signal line 19 to the control system 10. The valve device 17 is arranged in or on an air path 20 connecting the sensor device 16 and the filter element 14.

[0038] Between the filter elements 14 and 15, a further valve device 21 and a further sensor device 22 are positioned. The valve device 21 is arranged downstream of the sensor device 22. In particular, the valve device 21 is provided in or on an air path 23 connecting the sensor device 22 and the filter element 15. The sensor device 22 serves also for determining the air quality. In particular, the sensor device 22 can be configured to determine the air humidity of the inlet air L and loading thereof with harmful gases. The sensor device 22 is connected by means of a signal line 24 to the control system 10. The valve device 21 is connected by means of a signal line 25 to the control system 10.

[0039] A further sensor device 26 and a further valve device 27 are positioned between the filter element 15 and the lithium-air rechargeable battery 1, wherein the valve device 27 is arranged downstream of the sensor device 26. The sensor device 26 is operatively connected by a signal line 28 to the control system 10. The valve device 27 that is provided on or in an air path 29 connecting the sensor device 26 and the lithium-air rechargeable battery 1 is connected by means of a signal line 30 to the control system 10. Downstream of the lithium-air rechargeable battery 1, a further valve device 31 is provided which is connected by means of a signal line 32 to the control system 10. A vehicle control unit 33 of a vehicle communicates by signal lines 34, 35 with the control system 10.

[0040] In operation of the rechargeable battery assembly 6, the inlet air L flows first through the pre-separator 12 and the particle filter 13, whereby coarse and fine particles are removed from it. The sensor device 16 detects loading of the inlet air L, from which particles have been removed, with harmful gases and/or humidity. When the filtered inlet air L contains no harmful gases or only a quantity of harmful gases that is below a predetermined limit value, the inlet air L is guided by means of the valve device 17 and an air path 36 past the filter element 14 and past the sensor device 22 into the air path 23. When the inlet air L contains harmful gases to be removed, the valve device 17 is switched such that the inlet air L is guided through the filter element 14 in order to remove the harmful gases from the inlet air L.

[0041] Downstream of the filter element 14, the air quality of the inlet air L can be determined again by means of the sensor device 22. When loading with harmful gases is too high, the control system 10 recognizes that the filter element 14 must be regenerated. For this purpose, the valve device 21 is switched such that the inlet air L is guided into an air outlet 37. When the control system 10 detects by means of the sensor device 22 that the relative air humidity of the inlet air L already corresponds to a desired value, the valve device 21 is switched such that the inlet air L is guided via an air path 38 past the filter element 15 and past the sensor device 26 into the air path 29. In case of a lithium-air rechargeable battery 1, preferably the entire humidity is removed from the inlet air L. When using other metals, for example, silicon, as the electrode 3, it may also be required to adjust the relative air humidity of the inlet air L to a defined value. Via the air path 38, the inlet air L is guided by the valve device 17 into the air path 29 when neither harmful gas filtration nor conditioning of the humidity of the inlet air L is required. When the humidity of the inlet air L is above a predetermined limit value, the valve device 21 is switched such that the inlet air L flows through the filter element 15 and the sensor device 26.

[0042] When the sensor device 26 determines too high a value of the humidity of the inlet air L even though the inlet air L has been passed through the filter element 15, the control system recognizes that the filter element 15 must be regenerated. Then the valve device 27 is switched such that the inlet air L flows to an air outlet 39. Here, the inlet air L can be heated and can be guided again through the filter element 15 in order to regenerate it. The filter element 15 with the humidity-conditioning properties, for example, silica gel, can be regenerated by heat. For this purpose, the filter element 15 is heated or the inlet air L that is flowing through the filter element 15 is heated. The valve device 31 can be switched such that the outlet air A of the lithium-air rechargeable battery 1 can flow into the environment.