Battery pack and matching vehicle

Abstract

Battery Assembly and Corresponding Vehicle The present invention relates to a battery assembly (10), comprising a battery housing (12) and a safety vent (16). The safety vent includes a connection fitting (30) and a safety means (34). The safety means has a blocked state, in which the safety means fluidly separates an internal space of the battery housing from the connection fitting, and a connected state. The safety means transitions from the blocked state to the connected state when a predetermined pressure difference is exceeded between the internal space of the battery housing (12) and the connection fitting (30). The safety vent includes pressure-balancing means (40) that fluidly connect the internal space of the battery housing and the connection fitting when the safety means is in the blocked state. Figure for the abstract: Figure 1

Description

Title of the invention: Battery assembly and corresponding vehicle

[0001] The present invention relates to a battery assembly, of the type comprising a battery casing adapted to contain at least one battery cell, and a safety vent adapted to vent gas out of the battery casing, the safety vent comprising a connection tip, a safety vent body connected to the connection tip, and a safety means, the safety means having a blocking state in which the safety means fluidly separates an internal space of the battery casing from the connection tip, and a linking state in which the safety means fluidly links the internal space of the battery casing and the connection tip, and the safety means being adapted to selectively switch from the blocking state to the linking state when a determined pressure difference is exceeded between the internal space of the battery casing and the connection tip.

[0002] Battery assemblies are known comprising a battery casing containing a battery cell and a rupture membrane assembly adapted to vent gas out of the battery casing. Such an assembly is known from WO2022029380A1 (corresponding to EP4014277).

[0003] The rupture membrane assembly comprises a membrane retainer, a rupture membrane, and a mounting flange. The rupture membrane is designed to rupture when a pressure difference between the two sides of the membrane exceeds a threshold pressure difference.

[0004] A battery assembly is also known as WO2014131063A2 (corresponding to EP2959522). In this document, the membrane retainer and a mounting flange include pressure equalization openings that connect the battery housing to the environment surrounding the battery housing.

[0005] Other battery sets are known to be WO2013072468A2 (corresponding to EP2780962) and WO2014131875A1 (corresponding to EP2962340).

[0006] The invention aims to provide a battery assembly that has high reliability while being economical.

[0007] For this purpose, the invention relates to a battery assembly as indicated above characterized in that the safety vent includes pressure balancing means fluidly connecting the internal space of the battery casing and the connection tip when the safety means is in the blocked state.

[0008] According to particular embodiments of the battery assembly, it may include one or more of the following characteristics:

[0009] - the safety means includes a shutter element and in which the means pressure balancing systems include a pressure balancing opening;

[0010] - the obturator element comprises a rupture disc or a rupture membrane, adapted to break under the effect of a determined pressure difference between the internal space of the battery casing and the connection tip;

[0011] - the safety means includes a valve, in particular a non-return valve, in in which the valve is provided with a valve body and a valve obturator element, and in which the obturator element is the valve obturator element;

[0012] - the pressure equalization opening is provided in the obturator element;

[0013] - the safety means is disposed in the safety vent body, and the opening pressure balancing includes a bypass channel provided in the safety vent body;

[0014] - the pressure balancing opening comprises one or more openings between the shutter element and the safety vent body; and

[0015] - the battery assembly includes a gas vent hose connected to the nozzle of connection and the gas vent pipe is connected to a gas vent port.

[0016] The invention also relates to a vehicle, comprising an outer wall delimiting an interior of the vehicle and an exterior of the vehicle, the vehicle further comprising a battery assembly disposed inside the vehicle, characterized in that the battery assembly is a battery assembly as defined above and in that the connection tip is connected to the outer wall of the vehicle for the purpose of venting the gas to the outside of the vehicle.

[0017] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings, in which:

[0018] [Fig-1] Fig. 1 schematically shows a vehicle comprising a set of battery according to a first embodiment of the invention;

[0019] [Fig.2] Fig.2 schematically shows an enlarged part of the battery assembly according to the first embodiment of the invention, the safety means being in its blocked state;

[0020] [Fig.3] The [Fig.3] corresponds to the [Fig.2], the safety means being in its connected state;

[0021] [Fig.4] The [Fig.4] schematically shows part of a battery assembly according to a second embodiment of the invention;

[0022] [Fig. 5] Figure 5 schematically shows part of a battery assembly according to a third embodiment of the invention; and

[0023] [Fig.6] Fig.6 schematically shows part of a battery assembly according to a fourth embodiment of the invention.

[0024] Figure 1 schematically represents a vehicle according to the invention, designated by the general reference numeral 2. Vehicle 2 may be selected from a list consisting of an aircraft, a railway vehicle, a road vehicle, or a maritime or river vehicle. Vehicle 2 comprises an outer wall 4 delimiting an interior of vehicle IV and an exterior of vehicle EV. The interior of vehicle IV forms, for example, a battery compartment.

[0025] The vehicle 2 includes a battery assembly 10 generally located inside the vehicle IV, and preferably inside the battery compartment.

[0026] When installed in a vehicle, the battery pack 10 is configured to provide electrical power. This electrical power is, for example, sufficient to propel the vehicle via an electric or hybrid motor (not shown). Alternatively or in addition, the electrical power is used to power navigation instruments and / or to power the vehicle's onboard comfort features.

[0027] According to the embodiments shown, the battery assembly 10 is arranged in the vehicle 2. Alternatively, according to unrepresented embodiments, the battery assembly is arranged in an electrical storage bay, for example formed by a stationary container.

[0028] The battery assembly 10 is advantageously arranged in a dedicated space.

[0029] The battery assembly 10 includes a battery housing 12 adapted to contain the minus one battery cell 14.

[0030] In this case, the battery assembly 10 comprises two battery cells 14. The battery assembly 10 may comprise more than two of these battery cells 14.

[0031] Each battery cell 14 or electrochemical element is, for example, a Lithium-Ion type battery cell.

[0032] In the present embodiment, two battery cells 14 are housed in the battery case 12. Alternatively, the battery case 12 houses more than two battery cells 14, for example four battery cells 14. Alternatively still, the battery case 12 houses a single battery cell 14.

[0033] The battery casing 12 is adapted to contain the flames and gases generated in the event of thermal runaway of a battery cell 14. The battery casing 12 is for example made of aluminium.

[0034] The battery assembly 10 is equipped with a safety vent 16 adapted to vent gas out of the battery housing 12. In the event of thermal runaway of one or more battery cells 14, the safety vent 16 vents the generated gases out of the battery housing 12.

[0035] The battery housing 12 includes a housing wall 18, which is an outer wall of this battery housing, and which is provided with a through opening 20 in which the safety vent 16 is disposed (see [Fig.2]).

[0036] Referring again to [Fig.1], the battery assembly 10 includes a gas vent pipe 22 connected to the safety vent 16, in order to vent out of the battery casing 12 the gases generated during a failure of battery cell(s) 14.

[0037] The vehicle 2 also includes a gas vent port 24 disposed in the outer wall 4. The gas vent pipe 22 is connected to this gas vent port 24 in order to convey the gases generated during a failure of the battery cells 14, through the gas vent pipe 22, out of the vehicle.

[0038] The gas pipe 22 is advantageously gas-tight along its entire length and therefore only has the safety vent 16 and the gas vent port 24 as inlet and outlet points. This prevents contamination of the interior of the vehicle IV or the battery compartment with gases from the battery. Furthermore, contamination of the interior of the battery casing with moisture or other pollutants from inside the vehicle IV or the battery compartment surrounding the battery casing is prevented.

[0039] Figure 2 shows a portion of the battery assembly 10 of Figure 1 at a larger scale and in cross-section. More specifically, Figure 2 shows a portion of the casing wall 18 and the safety vent 16. The outer wall 4, the gas vent pipe 22, and the gas vent port 24 are shown only schematically in dashed lines.

[0040] The safety vent 16 includes a connecting end 30, in this case tubular, a safety vent body 32, fixed to the connecting end 30, and a safety means 34. The safety vent 16 also includes a fixing member 36, for example a nut.

[0041] The connection fitting 30 and / or the safety vent body 32 is / are, for example, made of metal. In this case, the connection fitting 30 and the safety vent body 32 are a single unit, preferably a single piece.

[0042] The safety vent body 32 extends through the through opening 20. The safety vent body 32 is fixed by the fixing member 36 on the housing wall 18. The safety vent body 32 is connected to the housing wall 18 in a gas-tight manner, for example by a sealing gasket, not shown.

[0043] The safety vent body 32 is also provided with a fixing flange 38 which extends on the side of the housing wall 18 opposite the fixing member 36.

[0044] The safety means 34 has a blocked state in which the safety means 34 fluidly separates the internal space of the battery housing 12 from the nozzle connection 30, and a connection state in which the safety means 34 fluidly connects the internal space of the battery housing 12 and the connection tip 30.

[0045] The tubular connection fitting 30 is connected to the outer wall 4 of the vehicle for the purpose of venting the gas to the outside of the vehicle, in this case via the vent pipe 22.

[0046] In [Fig. 2], the safety means 34 is shown in its blocked state. In this blocked state, gases from the battery cells 14 are prevented by the safety means 34 from flowing into the connection nozzle 30 and thus towards the gas vent pipe 22.

[0047] The safety means 34 is adapted to selectively switch from the blocking state to the linking state when a determined pressure difference AP=Pcarrier-Ppipe is exceeded between the internal space of the battery housing 12 and the connection tip 30, more precisely the inside of this connection tip 30. The safety means 34 is thus adapted to release when a pressure difference equal to or greater than the determined pressure difference AP.

[0048] The determined difference in AP pressure is for example between 1.5 bar and 3 bar.

[0049] The safety vent 16 further includes pressure balancing means 40 fluidly connecting the internal space of the battery housing 12 and the connection tip 30 when the safety means 34 is in the blocked state, and particularly permanently.

[0050] The pressure balancing means 40 have, for a given pressure difference between the internal space of the battery housing 12 and the connection fitting 30, a gas flow rate lower than the gas flow rate of the safety means 34 in the connected state. The pressure balancing means 40 fluidically connect the internal space of the battery housing 12 and the connection fitting 30 such that a pressure difference between the internal space of the battery housing 12 and the inside of the connection fitting 30 is equalized in a few seconds, for example in less than 2 seconds.

[0051] The pressure balancing means 40 are adapted to allow the establishment of the determined pressure difference during a failure of a battery cell 14. Thus, the pressure balancing means 40 fluidly connect the internal space of the battery housing 12 and the connection tip 30 in such a way that, when the determined pressure difference AP is established or exceeded, this pressure difference is equalized in a time greater than the time required to trigger the transition of the safety means 34 from the blocking state to the connecting state.

[0052] By way of example, for a given pressure difference, the gas flow rate of the pressure balancing means 40 is less than 1 / 10 of the gas flow rate of the safety means 34 in the bonded state.

[0053] The pressure balancing means 40 include, for example, a pressure balancing opening 42. The pressure balancing opening 42 includes in this case a bypass channel 44 provided in the safety vent body 32. The bypass channel 44 is in this case bent, but it can also be straight along its entire length.

[0054] In this case, the safety means 34 includes a sealing element 46. This sealing element 46 comprises or consists of a rupture disc or a rupture membrane 48 that is adapted to rupture under the effect of a predetermined pressure difference between the internal space of the battery housing and the connection tip. The rupture disc or rupture membrane 48 is, for example, made of a metal or a metal alloy. The sealing element 46 is attached to the safety vent body 32, for example by bonding or welding or by complementary shapes. By way of example, the rupture disc 48 may include the characteristics of the disc 400 disclosed in US9412985B2, column 7, lines 34 and following, and having one or more thinned areas.

[0055] In this case, the safety means 34 is disposed in the safety vent body 32.

[0056] Figure 3 corresponds to Figure 2 and shows the safety means 34 in its connected state. In its connected state, the safety means 34 allows gases from the battery cells 14 to flow freely through the connection nozzle 30 and towards the gas vent pipe 22.

[0057] As can be seen, the rupture disc 48 is in the ruptured state and therefore establishes a fluidic connection allowing gases from the battery cells 14 to flow freely in the connection nozzle 30 and therefore towards and into the inside of the gas exhaust pipe 22.

[0058] Referring again to [Fig. 1], the battery housing 12 is in this case equipped with a breather port 60, which connects the inside of the battery housing 12 to the inside of the vehicle IV. The function of the breather port 60 is to equalize the pressures between the inside of the battery housing and the environment around the battery housing, i.e., the inside of the vehicle IV. This reduces the mechanical stresses acting on the battery housing 12 and on the safety device 34, in particular on the rupture disc or the rupture membrane 48. This breather port 60 is, however, optional.

[0059] The battery assembly operates in the following manner.

[0060] All battery cells 14 are in normal operating condition. The safety means 34 is in the blocked state.

[0061] When a gas pressure difference is established between the gas vent pipe 22 and the inside of the battery casing 12, this pressure difference being less than the determined pressure difference, the pressure balancing means 40 lead to the equalization of the pressure between the inside of the battery casing 12 and the gas vent pipe 22. Thus the gas pressure upstream and downstream of the safety means 34 is equalized and the safety means 34 is subjected only to weak mechanical stresses.

[0062] In the event of a failure of one of the battery cells 14, for example during a thermal runaway, gas is generated, which causes the gas pressure inside the battery casing 12 to increase rapidly since the pressure balancing means 40 only allow a very low flow rate.

[0063] When the pressure difference between the inside of the battery casing 12 and the inside of the gas vent pipe 22 reaches or exceeds the predetermined pressure difference AP, the safety means 34 releases and transitions from the blocked state to the connected state. In this case, the transition from the blocked state to the connected state is the rupture of the rupture disc or rupture diaphragm 48.

[0064] Thus, the gases generated by the failure of the battery cells 14 are evacuated from the battery casing 12.

[0065] Once the gas pressure in the exhaust pipe 22 is sufficiently high, the gas exhaust port 24 opens and the gases are evacuated out of the vehicle 2.

[0066] Figure 4 shows a second embodiment of the invention. Figure 4 corresponds to [Fig. 2]. Only the differences compared to the first embodiment will be described. Analogous elements bear the same references.

[0067] The pressure equalization opening 42 is provided not in the safety vent body 32, but in the sealing element 46, in particular in the rupture disc or in the rupture membrane. The safety vent body 32 is therefore devoid of a pressure equalization opening 42.

[0068] In this case, the pressure balancing opening 42 is a through orifice 44, and not a bypass channel. The dimensions of the through orifice 44 are chosen such that the function of the through orifice 44 is identical to the function of the bypass channel of the first embodiment.

[0069] In this case, a through orifice 44 is provided in the center of the obturator element 46.

[0070] Figure 5 schematically represents part of a battery assembly according to a third embodiment of the invention. The view corresponds to the view of [Fig. 2], omitting the outer wall 4, the gas vent pipe 22, and the gas vent port 24. Only the differences compared to the first embodiment will be described. Similar elements bear the same reference numerals.

[0071] The pressure balancing opening 40 comprises one or more pressure balancing openings 42 which are in this case one or more openings through-hole(s) formed between the shutter element 46 and the safety vent body 32.

[0072] The shutter element 46 is fixed to the safety vent body 32 by a material connection, such as by welding, brazing or gluing.

[0073] In the present case, this / these through opening(s) is / are formed by one or more locations where there is a lack of sealing. In this instance, each through opening is formed by a gap between points of material connection fixing the shutter element 46 to the safety vent body 32.

[0074] Figure 6 schematically represents part of a battery assembly according to a fourth embodiment of the invention. Figure 6 corresponds to Figure 2, omitting the outer wall 4, the gas vent pipe 22, and the gas vent port 24. Only the differences compared to the first embodiment will be described. Similar elements bear the same reference numerals.

[0075] According to this fourth embodiment, the safety means 34 comprises a valve 70, in particular a non-return valve. The valve 70 is provided with a valve body 72, which forms the safety vent body 32, and a valve obturator element 74, which forms the obturator element 46. The valve obturator element 74 is shown in solid lines in its closed position and in dashed lines in its closed position.

[0076] In the case shown, each pressure balancing opening 42 is formed by a recess located between the valve body 72 and the valve obturator element 74 and remaining in the closed state of the valve 70. More specifically, each pressure balancing opening 42 is formed by a groove provided in the valve body 72.

[0077] Alternatively or in addition (not shown), the pressure balancing opening is provided in the valve obturator element 74 and is for example a conduit passing through the valve obturator element 74.

[0078] In an alternative not shown, the vehicle 2 comprises a first battery pack, which is the aforementioned battery pack 10, and an additional battery pack, which also includes the characteristics of the aforementioned battery pack 10. In this case, the gas vent pipe 22 of each of the battery packs 10 is connected to a gas vent manifold pipe which is in turn connected to the gas vent port 24.

[0079] Alternatively, the invention does not relate to a vehicle, but to a stationary storage bay. In this case, the vehicle 2 is replaced by a stationary storage bay. This stationary storage bay comprises an outer wall, which corresponds to the outer wall 4. The outer wall delimits a storage bay interior, which corresponds to the interior of the vehicle IV, and a bay exterior. storage, which corresponds to the exterior of the EV vehicle. The storage bay includes a battery pack which is identical to the battery pack 10 described above in connection with vehicle 2.

[0080] Such a battery assembly is intended for use within an electrical power storage system, particularly when the storage system is installed in a vehicle such as an aircraft, a rail vehicle, a road vehicle, or a maritime or river transport vehicle. Alternatively, the battery assembly is intended for static electrical energy storage, for example, in the form of at least one electrical storage bay in which several battery modules are stacked.

[0081] The present invention therefore generally proposes to provide a static pressure balancing device on the safety vent or on the safety valve device, between the battery and the gas evacuation system, in order to balance the pressure of the gas evacuation pipe with the battery.

[0082] The static pressure balancing device must obviously not allow gas flows contrary to the hermetic function but is just sufficient to balance the pressure over the medium term.

[0083] The arrangement of the pressure balancing openings at the locations disclosed in this description provides, as applicable, among other advantages, the following: the absence of the need for an opening in the battery housing, the absence of the need to provide aligned orifices in different components, the absence of the need to provide openings in the gas exhaust pipe.

[0084] Furthermore, the assembly according to the invention makes it possible to limit the pressure difference between the upstream and downstream sides of the obturator element. The described arrangement also makes it possible to ensure the reliable triggering of the rupture disc or rupture membrane and to trigger it at a relatively low pressure difference. The invention makes it possible to eliminate or omit a pressure balancing device at the outlet of the discharge pipe. The assembly according to the invention makes it possible to equalize pressures without risk of contaminating the battery room in the event of an evacuation.

[0085] The assembly according to the invention is therefore economical to manufacture and leads to significant reliability.

[0086] The preceding description contains technical features of the invention. These technical features, although presented in a technical context and possibly in combination with other technical features, can each time be used individually, without the other technical features, insofar as this is technically possible.

Claims

Demands

1. Battery assembly (10), of the type comprising a battery housing (12) adapted to contain at least one battery cell (14), and a safety vent (16) adapted to vent gas out of the battery housing, the safety vent comprising a connection tip (30), a safety vent body (32) connected to the connection tip, and a safety means (34), the safety means having a blocking state in which the safety means fluidly separates an internal space of the battery housing from the connection tip, and a linking state in which the safety means fluidly links the internal space of the battery housing and the connection tip, and the safety means being adapted to selectively switch from the blocking state to the linking state upon exceeding a specified pressure difference (AP) between the internal space of the battery housing (12) and the connection tip (30),characterized in that the safety vent comprises pressure balancing means (40) fluidly connecting the internal space of the battery housing and the connection nozzle when the safety means is in the blocked state, in that the safety means (34) comprises a shutter element (46), in that the pressure balancing means comprise a pressure balancing opening (42), and in that - the pressure balancing opening is provided in the shutter element, and / or - the pressure balancing opening comprises one or more openings between the shutter element (46) and the safety vent body (32).

2. Battery assembly according to claim 1, wherein the sealing element (46) comprises a rupture disc or rupture membrane (48), adapted to rupture under the effect of a determined pressure difference between the internal space of the battery housing and the connection tip.

3. Battery assembly according to claim 1 or 2, wherein the safety means (34) comprises a valve (70), in particular a non-return valve, in which the valve is provided with a valve body (72) and a valve obturator element (74), and in which the obturator element (46) is the valve obturator element (74).

4. Battery assembly according to any one of claims 1 to 3, wherein the safety means (34) is disposed in the safety vent body (32), and wherein the pressure balancing opening includes a bypass channel (44) provided in the safety vent body (32).

5. Battery assembly according to any one of claims 1 to 4, wherein the battery assembly includes a gas vent hose (22) connected to the connection nozzle and wherein the gas vent hose (22) is connected to a gas vent port (24).

6. Vehicle (2), in particular aircraft, of the type comprising an outer wall (4) delimiting an interior of the vehicle and an exterior of the vehicle, the vehicle further comprising a battery assembly disposed inside the vehicle, characterized in that the battery assembly is a battery assembly (10) according to any one of claims 1 to 5 and in that the connection tip (30) is connected to the outer wall of the vehicle for the purpose of venting the gas to the exterior of the vehicle.