Battery module capable of managing internal overpressure
Patent Information
- Application Number
- EP2023817749
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-20
- Filing Date
- 2023-12-04
- Publication Date
- 2025-10-29
AI Technical Summary
Electric accumulator modules face risks of thermal runaway and explosion due to abnormal pressure increases, which existing safety mechanisms inadequately address, and accessing components for recycling is complicated without causing deterioration.
An accumulator module with a housing box featuring a line of weakness in its face, allowing controlled rupture and evacuation of gases and heat in case of overpressure, facilitated by a conduit system and attachment interface for safe opening and component access.
The solution effectively manages overpressure by ensuring controlled release of gases and heat, reducing fire risks and enabling safe access for recycling without damaging the components.
Smart Images
Figure 1.1
Abstract
Description
Description Title of the invention: Accumulator module capable of managing internal overpressure
[0001] [The present invention relates to the field of electric accumulators for vehicles and more particularly to the field of electric accumulators capable of managing an abnormal increase in internal pressure.
[0002] When they are built, electric accumulators are made in the form of a set of individual electrochemical cells gathered inside a module forming an electric accumulator. These different cells are thus connected to each other via respective terminals to allow the storage and restitution of electrical energy by the electric accumulator.
[0003] Given the chemistries used in the operation of the electrochemical cells that make up an electric accumulator, degradation or malfunction of one of the cells is likely to cause a thermal runaway phenomenon with the release of flammable gases inside the accumulator. When such a situation occurs, the incendiary phenomenon that occurs is likely to spread extremely quickly by thermal radiation to the rest of the electric battery, in particular to adjacent cells that are also sensitive to high temperatures, or even to the rest of the vehicle from the cell concerned. Similarly, the generation of flammable gases inside the accumulator is likely to cause overpressure, potentially leading to an explosion of the battery.In order to limit such fire risks, various devices are put in place such as monitoring of cell temperature and / or their voltages associated with computers, fuse mechanisms and / or battery charge management. However, these mechanisms are not always sufficient to eliminate any risk of explosion and spread of fire by thermal radiation.
[0004] Furthermore, given the protective elements that surround these cells to limit the risks of thermal runaway, it is particularly complex, if not impossible, to access each of the different components of the battery module, and in particular to the cells housed inside this module, without these undergoing deterioration during its opening. Also, as part of a battery module recycling process, these are crushed, initially, before various purification stages are implemented to recover some of the elements which compose these modules.
[0005] The present invention aims to overcome these drawbacks by proposing a device for housing the cells of an accumulator which allows management of the risks of thermal runaway and explosion of a battery while providing a solution facilitating access to the components of the accumulator module likely to be necessary as part of an improved recycling process.
[0006] The invention thus relates to an accumulator module comprising a housing box inside which a plurality of electrochemical cells are juxtaposed so that the connection terminals of the cells are connected with an electrical connection interface carried by the housing box, the housing box comprising a box and an associated cover of dimensions complementary to those of the box and fixed to the box by a sealed connection on the periphery of the cover, characterized in that the accumulator module comprises means for managing an overpressure in its interior volume comprising a line of weakness in the thickness of one of the faces of the housing box, this line of weakness running along at least part of the edge of one face of the housing box,so that at least a portion of the line of weakness is weakened to break in a localized and circumscribed manner in the event of overpressure inside the housing box beyond a threshold value.,
[0007] The invention also relates to a battery box for housing a plurality of accumulator modules according to the invention, the accumulator modules being juxtaposed to be positioned at respective dedicated individual locations, characterized in that the box comprises, in its interior volume, at least one conduit comprising, on the one hand, a first orifice open at an external surface of the box and, on the other hand, at least one second orifice which surrounds at least the most weakened line of weakness of the face of an accumulator module, so that, in the event of overpressure in the accumulator module box, the rupture of the line of weakness causes guided evacuation towards the outside of the box of the heat and fumes of any pressurized gases.
[0008] The invention also relates to a method for opening the cover of a battery module which can be implemented as part of an operation for recycling the components of this battery module.
[0009] The invention will be better understood from the following description, which relates to different embodiments given as non-limiting examples, and explained with reference to the appended schematic drawings, in which:
[0010] [Fig. 1] represents a schematic illustration of an example of assembly of elements participating in the production of a part of an accumulator module according to the invention,
[0011] [Fig. 2] represents a schematic illustration of an example of a cover for producing an accumulator module according to the invention,
[0012] [Fig. 3] represents a schematic illustration of an example of a completed cover for producing an accumulator module according to the invention,
[0013] [Fig. 4] represents a schematic illustration of an example of a conduit intended to be associated with several accumulator modules for the production of a battery box according to the invention,
[0014] [Fig. 5] represents a schematic illustration of an example of assembly of conduits to different accumulator modules for the production of a battery box according to the invention,
[0015] [Fig. 6] represents a schematic illustration in section of an example of a conduit assembled to an accumulator module inside a battery box according to the invention before tearing of one face at the level of a line of weakness,
[0016] [Fig. 7] represents a schematic illustration in section of an example of a conduit assembled to an accumulator module inside a battery box according to the invention after tearing of one face at the level of a line of weakness,
[0017] [Fig. 8] represents a schematic illustration of an example of cooperation of a tool with a hooking interface for opening a face of an accumulator module according to the invention.
[0018] [Fig. 9] represents a schematic illustration of an example of opening a face of an accumulator module according to the invention by a tool.
[0019] The invention relates to an accumulator module 1 comprising a housing box 11 inside which a plurality of electrochemical cells 12 are juxtaposed so that the connection terminals of the cells are connected with an electrical connection interface 13 carried by the housing box 11, the housing box 11 comprising a box 111 and an associated cover 112 of dimensions complementary to those of the box 111 and fixed to the box 111 by a sealed connection on the periphery of the cover 112, characterized in that the accumulator module 1 comprises means for managing an overpressure in its interior volume comprising a line of weakness 21 in the thickness of one of the faces 2 of the housing box 11, this line of weakness 21 running along at least part of the edge of a face 2 of the housing box 11,so that at least a portion 22 of the line of weakness 21 is weakened to break in a localized and circumscribed manner in the event of overpressure inside the housing box 11 beyond a threshold value.,
[0020] The accumulator module 1 of the invention is thus arranged to allow a controlled opening of the housing box 11 in the event of overpressure, that is to say an opening of the housing box 11 strictly circumscribed to a very specific zone of one of its faces 2, so as to allow a release, on the one hand, of the gases under pressure inside the housing box 11 and, on the other hand, of the heat released by the chemical reaction of the components of the cells. The opening made at the level of one of the faces 2 of the housing box 11 is made by a controlled tearing of the face 2 under the effect of the pressure exerted by the gas release inside the housing box 11. The force exerted by the gas under pressure against the inner face of the housing box 11 causes a deformation of this face 2 and its tearing.The tear control of the face 2 of the housing box 11 is carried out by the creation of a zone of weakness 21 strategically positioned on one of the faces 2 of the. housing box 11. The weak zone 21 corresponds to an area of the face 2 at the level of which the resistance to pressure is less important so as to circumscribe the deformation and the tearing of the face 2 at the level of this single and unique zone 21. By way of example, this weak zone 21 is likely to be formed by a portion of the face 2 of the housing box 11 made of a material which has a hardness or a resistance lower than the rest of the face 2 of the housing box 11. By way of preferred example, likely to be combined with the previous example, this weak zone 21 is produced in the form of a portion of the face 2 whose thickness is reduced or thinned compared to the rest of the face 2 of the housing box 11.Also, a pressure exerted at the level of this zone of weakness 21 makes it possible to obtain a tear in the face 2 of the housing box 11 while avoiding, thanks to the difference in resistance, that this tear does not extend to the level of other portions of the face 2 of the housing box 11. This zone of weakness 21 has the shape of at least one line so as to make it possible to obtain a tear in the face 2 which forms a substantially clean and strictly delimited break, or even similar to a cutting line of the face 2. This line of weakness 21 is capable of adopting a rectilinear and / or curved arrangement. Similarly, this line of weakness 21 is capable of having a distribution in the form of a network of branches in which different portions of lines are attached by one or more of their ends.
[0021] According to an example corresponding to a construction variant capable of being combined with the construction method detailed above, the line of weakness 21 is carried by the cover 112 and positioned along at least part of the junction of the cover 112 with the box 111. According to this construction example, the integration of the line of weakness 21 into the cover 112 of the housing box 11 makes it possible to open the housing box. II at the level of the face of the box 111 which carries an opening for the insertion of the internal elements constituting the accumulator module 1 in the box III and which is closed by the cover 112. The positioning of a line of weakness 21 near the junction between the cover 112 and the box 111 makes it possible to take advantage of the solidity or rigidity or resistance of this watertight junction. This proximity thus makes it possible to obtain a difference in resistance and rigidity of the line of weakness 21 with the cover 112 / box 111 junction which is greater than with the central part of the cover 112, more apt to deform under the effect of pressure. This difference in strength and rigidity is thus more likely to facilitate the tearing of the line of weakness 21.
[0022] Furthermore, it should be noted that positioning a line of weakness 21 and therefore the associated possible opening, at the level of the upper face 2 of the housing box 11, allows the opening of the face 2 of the housing box 11 to release the pressurized gas and / or heat while preventing a liquid or solid element from flowing or accidentally exiting the interior of the housing box 11.
[0023] According to an example corresponding to another construction variant also capable of being combined with each of the previously detailed variants, the face 2 carrying the line of weakness 21 comprises a hooking interface 3 accessible at its outer surface, this hooking interface 3 being positioned close to the line of weakness 21, between the line of weakness 21 and the central part of the face 2 which carries this line of weakness 21. This hooking interface 3 has an arrangement for cooperation, direct or indirect, with a tool so as to allow traction on the hooking interface and the opening of the face 2 along the line of weakness 21. The hooking interface 3 forms a gripping element on the face 2 which carries the line of weakness 21 to carry out a controlled opening of the housing box 11 from the outside.When the line of weakness 21 is arranged over the entire, if not the essential, perimeter of the face 2 which carries it, this attachment interface 3 also makes it possible, in addition to opening the housing box 11, to remove a part of the face 2 surrounded by the line of weakness 21 and which carries the attachment interface 3. Also, in the context of an operation for recycling all or part of the accumulator module 1, the opening and / or removal of at least a part of the face 2 which carries the line of weakness 21 and the attachment interface 3 makes it possible to effectively access the contents of the housing box 11 without this opening / removal damaging the elements housed in the housing box 11.
[0024] According to an example corresponding to a specific construction variant of the previously detailed variant, the accumulator module 1 having a orthogonal shape, the hooking interface 3 is positioned near an angle of the face 2 which carries the line of weakness 21. This particular positioning makes it possible to have an off-centered hooking interface 3 on the face 2 to be removed, that is to say near the line of weakness 21. Also, the tensile force exerted by means of this hooking interface 3 near the line of weakness 21 makes it possible to operate an opening and a tearing from one to the next which is facilitated. In addition, the positioning of the hooking interface 3 at an angle of the line of weakness 21 makes it possible to operate a simultaneous tear along the two portions of the line of weakness 21 which form this angle.Likewise, the positioning of the attachment interface 3 near an angle allows a direction of traction which facilitates the tearing of the face 2 which carries the line of weakness 21 with a rupture along the line of weakness 21, in particular a direction substantially oriented along a bisector of the angle near which the attachment interface 3 is positioned.
[0025] According to another example corresponding to another specific construction variant capable of being combined with the previously detailed variant, the attachment interface 3 comprises an orifice passing 31 through the thickness of the face 2 coaxial with the threading of a blind nut 32 fixed tightly against the interior surface of the housing box 11, the threading of the nut 32 being able to cooperate with a threaded connecting interface 331 of a traction device 33 to operate a tear of the face 2 of the housing box 11 which carries the line of weakness 21 along this line of weakness 21, or even a separation of a part of the face 2 relative to the rest of the housing box 11 of the accumulator module 1.The positioning of the nut 32 against the inner surface of the housing box 11 makes it possible to obtain a hooking interface 3 which does not project on the outer face 2 which carries the line of weakness 21 and therefore avoids additional bulk of the accumulator module 1 which would complicate its installation. On the contrary, this positioning of the nut 32 against the inner surface of the housing box 11 makes it possible to take advantage of a limited volume available inside the housing box 11. It should be noted that the threaded connecting interface 331 of the traction device 33 corresponds to an arrangement capable of being carried directly by a tool 332 making it possible to exert traction on the connecting interface 331 or,. alternatively, by an intermediate part, such as a screw, a part of which such as a hooking means 333 carried by one end is capable of cooperating with a dedicated interface of a tool 332, such as an element similar to a crowbar carrying a “V” arrangement capable of receiving and cooperating with the hooking means 333 produced by the head of a screw inserted into the thread of the nut 32.
[0026] According to an example corresponding to another construction variant also capable of being combined with each of the previously detailed variants, the line of weakness 21 is produced by a groove in the thickness of one of the faces 2 of the housing box 11, the weakening being proportional to the reduction in the thickness of the face 2 provided by the groove of the line of weakness 21. The weakening along a line of weakness thus makes it possible to guide the tearing of the face 2 of the housing box 11 by restricting the rupture of the face 2 to this single line of weakness 21. According to an example relating to a specificity of this construction variant, the line of weakness 21 has a groove which has different levels of depth.These different depth levels bring about differences in weakening of the structure of the face 2 at the level of juxtaposed portions of the groove, so that along the same groove of the line of weakness 21, the variation in the depth of the groove brings about a variation in the weakening. Under these conditions, the most weakened portion 211 of the line of weakness 21 is likely to be strategically positioned on the face 2 of the housing box 11. Thus, during an increase in the pressure inside the housing box 11, this most weakened portion 211 of the line of weakness 21 is led to tear as a priority.According to a specific, or even preferred, example of implementation of this construction variant, the most weakened portion 211 of the line of weakness 21 is positioned near an angle or a curvature of the line of weakness 21, that is to say at a junction between two portions of the line of weakness 21 arranged in different orientations. Such positioning of the most weakened portion 211 of the line of weakness 21 makes it possible to obtain, for an equivalent length of torn line of weakness 21, an opening for the evacuation of the suppressed gases which is larger than at a strictly rectilinear portion of the. line of weakness 21. Also, the evacuation of the excess gas pressure and heat will be able to be carried out more efficiently, as soon as a pressure threshold value causing the rupture of the face 2 which carries the line of weakness 21 is reached. In addition to at least one more weakened portion 211, the line of weakness 21 also comprises at least one portion 212 whose weakening is less significant, that is to say a portion 212 corresponding to a groove whose depth in the thickness of the face 2 which carries the line of weakness 21 is less significant than that of the most weakened portion 211. This weakening is thus intended to facilitate the tearing of the face 2 of the housing box 11 without corresponding to a priority rupture zone or portion of the line of weakness 21.Also, in the context of an operation of opening the housing box 11, for example by using a hooking interface 3, the tearing of the face 2 is able to be carried out effectively along the entire line of weakness 21, independently of the level of weakening specific to each of the portions of the line of weakness 21.
[0027] The invention also relates to a battery box 4 for housing a plurality of accumulator modules 1 according to the invention, the accumulator modules 1 being juxtaposed to be positioned at respective dedicated individual locations, characterized in that the box 4 comprises, in its interior volume 41, at least one conduit 5 comprising, on the one hand, a first orifice 51 open at an external surface of the box 4 and, on the other hand, at least one second orifice 52 which surrounds at least the most weakened portion of the line of weakness 21 of the face 2 of an accumulator module 1, so that, in the event of overpressure in the housing box 11 of the accumulator module 1, the rupture of the line of weakness 21 causes a guided evacuation towards the outside of the box 4 of the heat and fumes of any pressurized gases.
[0028] Indeed, the evacuation of the pressurized gases and the heat extracted from the accumulator module 1 must also continue outside the battery box 4. This evacuation thus takes place via a dedicated conduit 5 specifically arranged to open, thanks to an orifice 51, at one of the external surfaces of the battery box 4. This conduit 5 is thus arranged inside the battery box 4 so as to surround in a substantially hermetic manner or seals at least the most weakened portion 211 of the line of weakness 21 carried by the face 2 of at least one accumulator module 1 housed in the battery box 4. The conduit 5 preferentially surrounds the portion of the face 2 of the accumulator module 1 at the level of which the opening is likely to occur, namely for example the portion 211 of the line of weakness 21 which presents the most significant weakening. The orifice 52 of the conduit 5 which surrounds this portion of the face 2 of the accumulator module 1 is thus structurally arranged to be adapted to the three-dimensional construction of the relevant portion of the accumulator module 1.The periphery of the orifice 52 of the conduit 5 is thus arranged to match the various surfaces and convolutions of the accumulator module 1 which surround the area of the face 2 and the line of weakness 21 at the level of which the opening is likely to occur under the effect of an increase in pressure in the housing box 11 of the accumulator module 1. Thus, when the face 2 which carries the line of weakness 21 is torn, the opening which forms through the housing box 11 of the accumulator module 1 provides communication between, on the one hand, the interior of the housing box 11 and, on the other hand, the interior of the conduit 5, thanks to the positioning of the orifice 52 of the conduit 5 around the priority area of tearing and opening formation of the face 2 of the housing box 11.According to an example of construction, the contact between, on the one hand, the periphery of the orifice 52 of the conduit 5 and, on the other hand, the housing box 11 of the accumulator module 1 is made by simple complementarity of shape and contact, possibly under stress, of the orifice 52 of the conduit 5 with the housing box 11, without perfect sealing being necessarily sought. However, this junction is also likely to be obtained with improved sealing by using a rubberized waterproof blade. The conduit 5 thus provides a means of evacuating and guiding the heat and fumes of the gases out of the battery box 4 so as to prevent these gases, fumes and heat from remaining in the interior volume 41 of the box 4 and causing an incendiary and uncontrolled chain reaction by thermal and / or chemical activation of the cells 12 housed in the various juxtaposed accumulator modules 1.Thus, the conduit 5 is made of a material selected to be sufficiently heat resistant without deformation. A. An example of a material among others that could be selected would be acrylonitrile butadiene styrene also known as ABS.
[0029] According to an example corresponding to a construction variant capable of being combined with the construction method detailed above, the conduit 5 comprises an additional orifice 53 which surrounds at least the most weakened portion 211 of the line of weakness 21 of the face 2 of a second juxtaposed accumulator module 1. Thus, the conduit 5 is arranged to carry out an evacuation of gas and heat coming from several juxtaposed accumulator modules 1.
[0030] According to an example corresponding to another construction variant capable of being combined with the construction methods previously detailed, the duct 5 comprises an additional orifice 54 also open at an external surface of the box 4. By way of example, the orifices 51, 54 of the duct 5 open towards the outside of the box 4 are arranged at opposite lateral surfaces of the box 4. This arrangement makes it possible, thanks to the presence of at least two openings 51, 54 towards the external atmosphere of the box 4, to allow the creation of a pressure differential inside the duct 5, between the two orifices 51, 54, and thus facilitate the formation of an air flow through this duct 5 for the evacuation of gases, fumes and heat.As an example of construction, the conduit 5 is produced in the form of a substantially rectilinear tubular arrangement mounted across the battery box 4, so that each of the two orifices 51, 54 is positioned at the level of opposite faces of the box 4. Between these two orifices 51, 54, the central portion of the tubular conduit 5 comprises one or more orifices arranged to cooperate with the respective most weakened portions of the lines of weakness 21 specific to each of several accumulator modules 1 juxtaposed inside the battery box 4.
[0031] The invention also relates to a method of opening a face 2 carrying a line of weakness 21 of an accumulator module 1 according to at least one of the specific variants of the invention detailed previously, characterized in that the method comprises: - a step of inserting a threaded end of the connecting interface 331 of a traction device 33 inside the threading of the nut 32, through the through-orifice 31 of the face 2 of the accumulator module 1 which carries the line of weakness 21, - a traction step relative to the accumulator module 1 of the traction device 33 by the connecting interface 331 inserted at the level of the through-orifice 31 associated with the nut 32 to tear off the face 2 of the accumulator module 1 from the rest of the housing box 11.
[0032] According to an example corresponding to a variant of implementation of the method capable of being combined with the previously detailed variant, the traction device 33 comprises at least, on the one hand, an intermediate part which carries the connection interface 331 at a first threaded end and a hooking means 333 at a second end and, on the other hand, a tool 332 comprising an interface for cooperation with the hooking means 333 of the intermediate part.
[0033] Of course, the invention is not limited to the embodiments described and shown in the attached drawings. Modifications remain possible, particularly from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.
Claims
Claims
1. [Accumulator module (1) comprising a housing box (11) inside which a plurality of electrochemical cells (12) are juxtaposed so that the connection terminals of the cells are connected with an electrical connection interface (13) carried by the housing box (11), the housing box (11) comprising a box (111) and an associated cover (112) of dimensions complementary to those of the box (111) and fixed to the box (111) by a sealed connection on the periphery of the cover (112), characterized in that the accumulator module (1) comprises means for managing an overpressure in its interior volume comprising a line of weakness (21) in the thickness of one of the faces (2) of the housing box (11), this line of weakness (21) running along at least part of the edge of a face (2) of the housing box (11),so that at least a portion (22) of the line of weakness (21) is weakened to break in a localized and circumscribed manner in the event of overpressure inside the housing box (11) beyond a threshold value.,
2. Accumulator module (1) according to claim 1, characterized in that the line of weakness (21) is carried by the cover (112) and positioned along at least part of the junction of the cover (112) with the box (111).
3. Accumulator module (1) according to one of the preceding claims, characterized in that the face (2) carrying the line of weakness (21) comprises a hooking interface (3) accessible at its outer surface, this hooking interface (3) being positioned close to the line of weakness (21), between the line of weakness (21) and the central part of the face (2) which carries this line of weakness (21).
4. Accumulator module (1) according to claim 3, characterized in that, the accumulator module (1) having an orthogonal shape, the attachment interface (3) is positioned close to an angle of the face (2) which carries the line of weakness (21).
5. Accumulator module (1) according to one of claims 3 or 4, characterized in that the attachment interface (3) comprises a through orifice (31) the thickness of the face (2) coaxial with the thread of a nut (32) blind fixed tightly against the inner surface of the housing box (11), the threading of the nut (32) being able to cooperate with a threaded connecting interface (331) of a traction device (33) to operate a tear in the face (2) of the housing box (11) which carries the line of weakness (21) along this line of weakness (21), or even a separation of a part of the face (2) relative to the rest of the housing box (11) of the accumulator module (1).
6. Accumulator module (1) according to one of the preceding claims, characterized in that the line of weakness (21) is produced by a groove in the thickness of one of the faces (2) of the housing box (11), the weakening being proportional to the reduction in the thickness of the face (2) brought about by the groove of the line of weakness (21).
7. Battery box (4) for housing a plurality of accumulator modules (1) according to one of claims 1 to 6, the accumulator modules (1) being juxtaposed to be positioned at respectively dedicated individual locations, characterized in that the box (4) comprises, in its interior volume (41), at least one conduit (5) comprising, on the one hand, a first orifice (51) open at an external surface of the box (4) and, on the other hand, at least one second orifice (52) which surrounds at least the most weakened portion of the line of weakness (21) of the face (2) of an accumulator module (1), so that, in the event of overpressure in the housing box (11) of the accumulator module (1), the rupture of the line of weakness (21) causes a guided evacuation towards the outside of the box (4) of the heat and fumes from possible pressurized gases.
8. Battery box (4) according to claim 7, characterized in that the conduit (5) comprises an additional orifice (53) which surrounds at least the most weakened portion (211) of the line of weakness (21) of the face (2) of a second juxtaposed accumulator module (1).
9. Method for opening a face (2) carrying a line of weakness (21) of an accumulator module (1) according to claim 5, characterized in that the method comprises: - a step of inserting a threaded end of the connecting interface (331) of a traction device (33) inside the threading of the nut (32), through the through-hole (31) of the face (2) of the accumulator module (1) which carries the line of weakness (21), - a traction step relative to the accumulator module (1) of the traction device (33) by the connecting interface (331) inserted at the level of the through-orifice (31) associated with the nut (32) to tear off the face (2) of the accumulator module (1) from the rest of the housing box (11).
10. Method for opening a face (2) according to claim 9, characterized in that the traction device (33) comprises at least, on the one hand, an intermediate part which carries the connecting interface (331) at a first threaded end and a hooking means (333) at a second end and, on the other hand, a tool (332) comprising an interface for cooperation with the hooking means (333) of the intermediate part.