WO2012076808A1

WO2012076808A1 - Sealed, high-voltage battery pack

Info

Publication number: WO2012076808A1
Application number: PCT/FR2011/052883
Authority: WO
Inventors: Ludovic Lefebvre
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2010-12-10
Filing date: 2011-12-06
Publication date: 2012-06-14
Also published as: FR2968839B1; FR2968839A1

Abstract

The invention relates to a sealed, high-voltage battery pack (20) for a hybrid or electric vehicle, comprising a casing (50) containing cells (23) for the production, storage and release of electric energy, and a removable tank (25) containing a moisture absorbing material (34). The invention is characterised in that it comprises means (22, 37, 36) for maintaining the interior of the casing sealed when the removable tank (25) is removed.

Description

WATERPROOF HIGH VOLTAGE BATTERY PACK

The invention relates to a sealed high-voltage battery pack for a hybrid or electric vehicle, comprising cells for producing, storing and releasing electrical energy.

Economic pressure, linked in particular to the price of fuel, and environmental, particularly related to the regulation of pollutant emissions and greenhouse gases, encourages the development of electric or hybrid traction chain vehicles. Hybrid powertrain means a traction chain using two types of motorization, in series, in parallel or in power bypass, comprising an internal combustion engine and an electric motor.

Hybrid and electric vehicles include a high-voltage traction battery needed to drive the vehicle. In the case of an electric vehicle, the battery is generally the only source of energy on board to power the electric motor (s). In the case of a hybrid vehicle, the battery provides energy to an electric motor that provides a surplus of torque or mechanical power to boost the performance of the engine and reduce emissions.

Such a battery heats up not only by Joule and thermochemical effects in operation and recharge, but also by the current calls that result from certain conditions of use. The maximum permissible temperature levels by the battery, generate needs for thermal control. Generally, a temperature of the battery above 40 ° C to 50 ° C is pre-udiciable to its life and its dependability.

In order to cool the battery optimally even in extreme life situations, the trend current is to equip it with a thermoregulation which uses refrigerant taken through a bypass of the air conditioning circuit of the vehicle. This mode of cooling is justified by the increased solicitation of the battery on electric vehicles and fully hybrid vehicles (hybrids in English) which are hybrid vehicles with rechargeable battery from an external source.

These vehicles are required, in particular a long range of Zero Emission Vehicle (ZEV) sometimes ranging up to 30km for a hybrid vehicle and up to more than 200km for an electric vehicle, which is out of order. hybrid and first generation electric vehicles.

These vehicles are also required to provide longitudinal dynamic performances that make it possible to cope in an electric fashion with all urban, even peripheral and extra-urban situations, among which may be mentioned in a purely illustrative and nonlimiting way, the insertion into the traffic, the acceleration, overtaking, avoiding the use of the engine in the case of a hybrid vehicle, so as to maximize the gain in consumption.

These vehicles are still required to provide thermal comfort in terms of heating and cooling of the passenger compartment, equivalent to that of a conventional vehicle, especially in all-electric mode. This requirement imposes on the HV battery (high voltage) traction, to supply in addition to the movement organs, electrical consumers type electric air heater outside entering the cabin or electric compressor air conditioning system.

The traction battery HT must have a life of up to equal that of the vehicle (10 to 15 years and 200 to 300,000km). This requires thermo regulating the battery at the lowest possible temperature, especially in its optimal operating range, whatever the conditions of use.

The known solutions of the prior art do not meet all the constraints.

Document DE102008034698A1 describes a battery pack comprising an extractable reservoir which contains a moisture-absorbing material. The problem is that, during the extraction of the tank to renew the moisture absorbing material, a call for air in the battery pack may introduce humid air.

Other designs implement a perfectly sealed battery pack. The volume left free between the housing and the internal components of the battery pack such as its cells, its management electronics, is filled with vacuum or an inert gas or resin. Any after-sales intervention inside the battery pack is impossible. In addition, this type of design provides no solution to moisture management condensing inside the battery pack.

To remedy the problem posed by the prior art, the subject of the invention is a sealed high-voltage battery pack for a hybrid or electric vehicle, comprising a casing in which cells are arranged for production, storage and release. electrical energy, and an extractable reservoir which contains a moisture-absorbing material, characterized in that it comprises means for maintaining the seal inside the housing when extracting the extractable reservoir.

Advantageously, the means for maintaining the seal comprise on at least one casing face of the battery pack, one or more soft areas which deform so as to balance pressures inside and outside the battery pack. In particular, said face is in the upper part of the battery pack.

Advantageously also, the battery pack comprises a housing for the extractable reservoir disposed at the bottom of the housing, said housing having a settler wall in which is formed at least one orifice which allows a condensed liquid to flow to the absorber material contained in the extractable tank.

In particular, the extractable reservoir is in the form of a drawer and the means for maintaining the seal comprise at least one sealing device disposed on the bottom of the drawer so as to obstruct the housing when the drawer is brought into its extracted position.

More particularly, said device is arranged to obstruct the orifice when the reservoir is in the extracted position of the battery pack.

More particularly, the means for maintaining the seal comprise at least one plate on one side of the tank in contact with said settler wall, said plate being arranged to conceal the orifice during extraction of the tank.

Preferably, said housing comprises an opening which makes it possible to balance pressures inside and outside the housing during extraction of the tank.

Advantageously, the battery pack comprises a compartment separate from the cells and dedicated to the maintenance of the battery pack.

Optionally, the battery pack comprises an extractable reservoir clog valve driven by a return spring which is released by a withdrawal of the absorbent material so as to press the valve sealingly against a lower portion of the extractable reservoir.

Other features and advantages of the invention will emerge clearly from the description which is given below, as an indication and in no way with reference to the accompanying drawings, in which:

FIG. 1 is a known architecture diagram of refrigerant circuit with two parallel refrigeration loops;

FIG. 2A is a perspective view of an example of a coil-type evaporator integrated in an HV traction battery pack;

FIG. 2B is a perspective view of an example of a cold plate-type evaporator integrated in an HV traction battery pack;

FIG. 3 is a perspective view of a battery pack comprising an absorbent material according to the invention;

FIG. 4 is a sectional side view of the bottom of the battery pack of FIG. 3;

FIGS. 5A to 5G reproduce FIG. 4 for various steps leading to removal of absorbent material from the battery pack;

FIG. 6 reproduces FIG. 4 after removing the absorbing material from the battery pack;

Figures 7A to 7H reproduce Figure 6 for different steps leading to a replacement of absorbent material in the battery pack.

Figure 1 shows a thermal management system that allows to cool a battery pack 1 optimally, including in extreme life situations.

The thermal management system uses a refrigerant fluid taken from the air conditioning circuit of the vehicle via a bypass.

The air conditioning circuit of the vehicle is based in a known manner on a closed loop comprising a reservoir 8 equipped with a desiccant filter and which contains coolant in the liquid state, an evaporator 5 in which the refrigerant passes from the state liquid in the gaseous state, a compressor 6 which compresses and represses to a condenser 7, the gas produced by the evaporator 5. In the condenser 7, the refrigerant returns from the gaseous state to the liquid state before being returned to the reservoir 8.

In the cooling mode of the passenger compartment, the evaporator 5 is generally located in contact with an air supply duct in the passenger compartment (not shown) for the purpose of cooling it. In order to evaporate the refrigerant flowing through it, the evaporator 5 absorbs the heat of the air passing through the supply duct and thus causes its cooling. The condenser 7 is then generally located in contact with the outside of the passenger compartment. The heat released by the condensation of the fluid in the condenser is then discharged to the outside.

A pressure and thermostatic valve 9 makes it possible to control the flow of refrigerant fluid at the inlet of the evaporator 5 as a function of the pressure and the temperature of the outlet fluid so as to regulate the amount of heat absorbed in the evaporator 5.

The bypass for withdrawing the cooling fluid from the air conditioning circuit comprises a pipe 24 for bringing the refrigerant removed to the battery pack 1 and a pipe 29 to bring the refrigerant fluid of the battery pack into the air conditioning circuit. The upstream line 24 is connected between the tank 8 and the evaporator 5 upstream of the valve 9. The downstream line 24 is connected to the inlet of an evaporator inside the battery pack 1. L Upstream of the pipe 29 is connected at the outlet of the evaporator inside the battery pack 1. The downstream of the pipe 29 is connected between the evaporator 5 and the compressor 6 downstream of the evaporator 5.

A pressostatic and thermostatic valve 2 serves to control the flow of refrigerant circulating in the battery pack 1 according to the pressure and the temperature of the output fluid so as to regulate the amount of heat absorbed in the battery pack 1. Valves 2 and 9 each constitute a regulator respectively for the battery evaporator loop and for the passenger compartment evaporator loop.

An on-off valve 3 upstream of the expander 2, passes in an open state the refrigerant in line 24 to 1 evaporator of the battery 1 and blocks the passage of the fluid in a closed state.

An on-off valve 4 upstream of the expander 9 passes the cooling fluid to the evaporator 5 in an open state and blocks the passage of the fluid in a closed state.

The valves 3 and 4 make it possible to ensure or not the refrigeration of one loop without interfering with that of the other.

The thermal management system shown in FIG. 1 makes it possible to cool the battery pack 1 to respond to the increased demand of the battery on electric vehicles and fully hybrid vehicles (full hybrid in English) with rechargeable battery by an external source.

The refrigeration provided by the system of Figure 1, allows high cooling performance of the traction battery HT, with a favorable energy balance through a coefficient of performance generally taking values from 1.8 to 3.5 for refrigeration usual when the outside temperature varies in a range of 25 to 40 ° C. It is recalled that the coefficient of performance of a thermal system is the ratio equal to the amount of heat recovered, divided by the amount of work provided to recover this amount of heat. The coefficient of performance can be as high as 5 to 8 under warm ambient conditions of 5 to 20 ° C. Such temperature conditions favor the cooling of the high-voltage traction battery during usual life situations. The favorable energy balance is a first advantage that makes the thermal management mode that has just been described preferable when compared to other thermal management modes based for example on an outdoor air or air cooling from the cockpit, or on a cooling by simple circulation of water. Other advantages are that the thermal management mode based on a closed refrigeration loop is preferred.

The thermal management system based on a closed loop of refrigeration has the advantage of being independent of the ambient state in the passenger compartment which is subjected to the pollution of the air by the smoke of cigarette or the dust, to the panes open, the settings of the air conditioning group by the user of the vehicle that are not always favorable to the thermal management of the battery.

The closed loop refrigeration thermal management system has advantages in terms of operational safety and security that result from its isolation from the passenger compartment.

The absence of acoustic nuisance offers a particularly sought-after silence service in an electric or full hybrid vehicle in electric taxi.

The possible installation of the thermal management system under the bonnet, under the body and / or in the cabin of the vehicle, has the advantage of a small intrusion resulting from a lack of large section air ducts, additional heat exchanger and air blower to implement.

The extra cost generated is controlled compared to other thermal management modes.

The above-mentioned advantages push to equip any high-performance hybrid or electric vehicle dynamically or autonomously, with the thermal management system of FIG. ensure the refrigeration of the HV live traction battery by refrigerant in contact with the active cells of the battery.

The battery pack 1, as shown in FIG. 2A, consists of an assembly of cylindrical cells 10. Each cell 10 constitutes the place where the production, the storage and the release of electrical energy take place. Calories are released in each cell by Joule effect and by the exothermic thermochemical reactions that take place there. The casing or the wall of each cell 10 acts as a thermal conductor for evacuating the calories outside the cell to a coil-type exchanger 9. The exchanger 9 here plays the same role as the evaporator 5 of the air-conditioning unit of the passenger compartment shown in FIG. 1. An upstream expansion is followed by an evaporation of a refrigerant fluid of the R134a, CO2, HFO- 1234yf, or other within the exchanger 9. The expansion and 1 'evapora- tion are controlled by a pressure reducer, made for example by the valve 2 of calibrated orifice type pressostatic and / or thermostatic dedicated.

The battery pack 1, as shown in FIG. 2B, consists of an assembly of flat cells 11. Each cell 11 constitutes the place where the production, the storage and the release of electrical energy take place. The calories which are released in each cell 11 by the Joule effect and by the exothermic thermochemical reactions which take place therein, are evacuated through the housing or the wall of each cell 11 which acts as a thermal conductor, outside the cell up to a plate type exchanger 12 or flat tube. The plate heat exchanger 12 again plays the same role as the evaporator 5 of the air conditioning unit of the passenger compartment shown in FIG.

In one case as in the other, thermal conduction plates arranged in contact and / or between the cells can be provided to bring the calories to the evaporator type exchangers.

As shown in FIG. 3, the cells 23, 1 'evaporator 26, any conduction plates as well as battery management electronics, are enclosed in a housing 50, the whole constituting a battery pack 20 comparable to the battery pack 1 of Figure 1.

The casing 50 serves as a need for mechanical protection against small shocks like chippings, branches, small animals, sidewalk, protection against aggression of water, snow, salts, mud or other. The casing 50 can also serve as a screen or thermal insulation under the hood or under the vehicle body vis-à-vis the environment heated by the exhaust gas, the flow of hot air from the compartment engine. The housing can still be used to integrate the battery pack attachments to the vehicle. The regulator 2 is preferably outside the battery pack 20 in order to diversify the settings of a vehicle application to another without impacting the internal components of the battery pack.

The battery pack shown in FIG. 3 is refrigerated by a refrigerant supplied by line 24 and recovered via line 29. Refrigeration cooling poses many challenges. Some of these challenges are also common to all types of battery, whatever the mode of thermal management.

Good electrical insulation is essential on the one hand between the cells 23 and on the other hand vis-à-vis the refrigerant. The thermal contacts must be carefully studied in order to maintain a good heat exchange performance from the active heart of the cell where calories are produced to the coolant where the calories are absorbed. Particular attention should be paid in particular to the choice of materials between places of production and absorption of calories as well as on the surface conditions between each cell and the evaporator, whatever its technology. For example, it is possible to mount, in the casing closing the battery pack, the cells under stress against the evaporator or vice versa in order to exert a pressure between them which tends to remove any air space that can act as an insulating layer and thus promote heat exchange by thermal contact.

The thermal management by cooling loop leads by nature, when the coolant is sufficiently cold at the input of the battery, to a formation of condensation inside the battery pack. The condensation of the water vapor contained in the air present in the battery pack in contact with the cold evaporator, causes a runoff of water which leads to the presence of water condensates, or other liquids that it should be managed to reduce the risk of short circuits, electrochemical corrosion, and others.

Preferably, the housing of the battery pack is waterproof, especially when the battery pack is installed under the vehicle body or in the engine compartment. The waterproofness of the battery pack is intended to prevent any intrusion from the outside: water (rain, snow, puddle, fording, moisture contained in the outside air), salt removal, dust, etc.

It is also necessary to manage the expansion of the air contained in the battery pack. The expansion of the air results in particular from the heating of the battery pack. The expansion of trapped air creates a pressure differential between the inside of the battery pack and the outside environment.

A high level of tightness of the battery pack not only makes it possible to overcome any intrusion of water coming from outside, but also to limit the contribution of the moisture present in the outside air, thus reducing to the source the production of condensates. This moisture supply is, however, avoided only in as the battery pack has a high level of airtightness.

In order to avoid a humid air introduction into the battery pack, in particular in the case of opening of the casing to ensure a maintenance operation in after-sales service, for example for a fuse exchange, the maintenance areas for the after-sales services (fuses,...) are preferably located in a compartment 27 separated from the cells and the evaporator, accessible in APV by a cover equipped with seals. However, such tightness of the battery pack does not allow to evacuate to the outside condensates formed during operation of the battery refrigeration.

An additional circuit dedicated to degassing

(venting in English) eliminates from the battery pack any product gas (H2, CO, CO2, CH4, HF, ...) or liquid (electrolyte, dissolved gas) in case of runaway, failure or aging of the battery pack. This degassing circuit is dissociated from the thermal management system of the battery and is designed so that the degradation products of the battery are never in contact with the cells or with the internal thermal management system comprising one evaporator 26, the possible battery heater, and other fluid conduits 24, 29.

Given the cost price, the selling price, the warranty cost for the car manufacturer, and the purchase price and the cost of the associated after-sales labor for the customer, a battery pack complete, it is desirable to be able to intervene on it to open it and to replace it if necessary and in complete safety for the operators, the defective constituents, without having to exchange all the complete pack.

According to a first aspect, the battery pack 20 comprises, on at least one face 28 of its housing, one or more soft zones 22 occupying all or part of the surface of the face 28. Each soft zone 22 is positioned in a location with little or no load mechanically or thermally so as not to alter the resistance to mechanical and thermal stresses of the entire battery pack. The soft zone 22 consists of a material, for example rubber, which makes the zone 22 and its connection to the casing, on the one hand inert electrically and electrostatically, and on the other hand airtight, gas, to liquids, both from the outside to the inside and from the inside to the outside of the battery pack. The soft zone 22, of balloon or bellows type, has the function of absorbing expansions or volume shrinkage inside the battery pack, when the battery pack is respectively overpressure or depression relative to the external environment. Overpressure or depression may result from temperature and pressure conditions internal to the battery pack or from external conditions related to changes in the external environment in terms of temperature, atmospheric pressure, or altitude. It is recalled the need for the battery pack to be strictly watertight and as much as possible airtight so as to oppose any external air intake, in particular loaded with moisture, in the battery pack . The surface of the soft zone or zones 22 is dimensioned so as to absorb any expansion or volume shrinkage, taking into account in particular the volume of the battery 20, the pressures and the temperatures that may reign on both sides of the battery pack walls. , inside and outside the battery pack.

In a second aspect, a moisture absorbing material 34 is disposed in the lower portion of the battery pack housing 20. The moisture absorbing material 34 is in the form of a layer of moisture absorbing material and / or hygroscopic salts contained in sachets of hydrophilic material or in the form of a coating.

One option is to implement a supply of salts or absorbent materials in sufficient quantity to cover the life of the battery pack taking into account the extreme conditions of use. As an illustration, the most thermally demanding uses for the battery can be cited. To cool the battery pack, these uses make considerable use of refrigeration, which causes the formation of condensates. We can also mention extreme outdoor conditions related to changes in altitude and outside temperature, in terms of high outdoor temperature, humidity, and others.

This option can be expensive and cumbersome, which is why an alternative is preferred which, as described below, significantly reduces the amount of salts or other absorbent materials used.

An alternative option is to implement a lower quantity provision and a method of determining a convenient time to replace the provision that has been placed in the battery pack during factory assembly.

Data are already present in the vehicle computers for the management of the thermal comfort of the passenger compartment and for the thermal management of the battery in relation to the mode of operation of the power train among ZEV modes, full hybrid, and others . These data relate to the temperature of the battery pack, the outside temperature, the altitude, the temperature of the passenger compartment, the atmospheric pressure, the hygrometry, the frequency and the duration of use of the battery. refrigeration loop of the battery pack, the temperature and the pressure of the refrigerant inlet of the evaporator 1 inside the battery pack, and other parameters. The alternative option process exploits this pre-existing data to determine the appropriate timing based on the volume of salts or absorbent materials initially present in the battery pack and the volume of air in the battery pack. The method also determines the appropriate time according to the maintenance steps of the vehicle and the date of the last maintenance so as not to force the customer to visit the after-sales network only for this reason, even anticipating the replacement of the salts or absorbent materials.

For this purpose and in order to facilitate its replacement, a drawer-shaped reservoir 25 is placed in the lower part of the battery housing to contain the absorber material 34 in the form of absorbent salts or the like. Thus, in running order, the absorber material 34 is advantageously positioned under gravity settling, channeling and concentration of condensates to facilitate absorption. The reservoir, constituted in a preferred embodiment, by the slide 25 and in particular its guiding in the casing of the battery pack, are designed to expel the air that has entered the battery pack during its extraction for the exchange of the batteries. salts or hygroscopic materials.

Furthermore, it is possible to implement a heating (not shown) of the cells 23 of the battery pack 20 by means of different types such as thermistors with positive temperature coefficient (PTC), electrical resistors, use of the circuit refrigerant in heat pump mode, or others. The heating of the cells 23 of the battery pack 20 is particularly useful under cold external conditions to obtain faster high performance. The current that the battery pack can provide begins to drop as soon as the temperature drops below 20 ° C until to cancel below 0 ° C in Li-polymer technology or below a temperature ranging from -20 ° C to -40 ° C in Li-ion technology. Below low temperature limits that depend on the technology used, the battery pack is unavailable because it can not supply power.

Optionally, the heater is used to handle the condensates by vaporizing the moisture present to help regenerate the salts or absorbent materials of the battery pack by drying them. This opportunity if applied will however be managed by the strategy mentioned above in compromise between the cooling of the battery and the management of condensate, these two needs can intervene at the same time.

Thus, a battery adopting the process implementing these two aspects and, in a variant, the strategy described above, makes it possible to fully satisfy the constraints mentioned above, at a negligible additional cost, a low cost in maintenance and without impacting on the operation, the durability, safety, bulk, mass and conditioning of the battery and its integration into the vehicle.

Figure 3 details the principle of a battery pack 20 according to the invention. The battery pack 20 comprises cells 23. The cells 23 may be in various forms, for example prismatic as shown in dashed lines in FIG. 3. The battery pack 20 may also comprise cells 10 of cylindrical shape as represented in FIG. 2a. or any other form such as for example in a flexible bag. The cells 10 or 23 are generally connected in series in order to obtain a high voltage at the output of the battery pack 20.

A compartment 27 houses electronic components that provide electrical and electronic management of the battery pack 20. The components housed in the compartment 27, contain in memory control strategies, especially thermal management, and dialogue with vehicle computers. The compartment 27 is separated from the rest of the battery pack 20 by a watertight wall and firewall (not shown), so that any incident occurring in the part of the battery pack containing the cells can not affect the control and management of the pack. Battery 20. In order to maintain certain elements related to electronic components, for example fuses, a inspection hatch 21 is made in the housing. The inspection hatch 21 makes it possible to intervene in maintenance without dismantling the entire casing since this disassembly could put the entire pack, and in particular the battery cells 23, in contact with the outside air potentially loaded with moisture. . The inspection hatch 21 is equipped with a hinge to ensure its rotation relative to the housing of the battery pack 20. A seal 30, for example of the toric type, disposed on the periphery of the opening of the hatch 21, guarantees under normal conditions, the sealing of the access means to the electronic components, constituted by the hatch 21. The seal can be placed on the compartment 27 of the electronics or on the underside of the inspection hatch cover 21 for recovery with the housing. Closing the inspection hatch 21, for example by two screws or by clipping, causes compression of the seal 30.

The evaporator 26 which constitutes the refrigerant heat exchanger of the cells of the battery pack 20, is shown in dashed lines in FIG. 3. A refrigerant fluid flowing in the evaporator 26 from the pipe 24 to the pipe 29, has the effect of creating a cold surface in the battery pack 20. This cold surface is conducive to the formation of condensates.

A removable drawer 25 sliding in the lower case of the battery pack 20, is provided to contain a absorbent material, for example in the form of a layer or bags of desiccant salts. The mounting of the removable drawer 20 under the settling places by gravity, is arranged to channel and concentrate condensates. As for the inspection hatch 21, the sealing of the slide 25 with its interface on the lower casing of the battery pack 20, is achieved by a seal 40, for example of toric type, arranged all around the outside of the box. opening of the lower housing of the battery pack 20 or the end of the drawer 25 overlapping with the housing. The compression of the seal 40 is ensured by the closure of the slide 25, for example by two screws, by clipping or by any other locking means.

At least one soft zone 22 is formed, preferably in the upper part of the battery pack housing above the cells 23 in order, as explained above, to absorb the pressure differentials between the inside of the battery pack and the battery pack. ambient environment.

Figure 4 shows a decanter 32 which includes at least one inclined wall allowing the condensates to flow from the evaporator 26 along the wall of the decanter. At least one orifice 31 formed in the wall of the decanter 32, of the evacuation light type, allows the condensed liquid to flow to the drawer 25. An associated light made in an upper wall of the drawer 25 opposite the light discharge of the settler, allows the condensed liquid to reach the absorbent material 34 in the drawer.

The drawer 25 is sealed by fixing to the housing of the battery pack 20. The absorbent material 34 is in place and occupies the entire interior volume of the drawer 25.

A lower light 35 is located below the battery pack 20 at a position corresponding to the bottom of the drawer 25 when closed. In a first possible embodiment, the lower light 35 is sealingly obstructed by a device 36 provided with a seal and mounted on the bottom of the drawer 25. In a second possible embodiment, the lower light 35 is sealed by a valve (not shown) driven by a spring reminder sealingly by sealing a seal molded against the casing of the battery pack 20. Other embodiments are possible without departing from the scope of the present invention to the extent that they prevent any intrusion d water coming from outside.

Figures 5a to 5g illustrate a kinematic opening drawer to remove the absorbent material 34 to replace it.

Figure 5a shows a start of opening of the drawer 25. The attachment of the drawer 25 to the housing of the battery pack 20 is deactivated. The drawer 25 is translated into its housing by external action schematically an arrow 38. Grooves not shown on each longitudinal side of the drawer housing, guide the slide 25 in translation. The translation of the slide 25 can create a slight suction, which in this case releases a passage to the outside air by the lower light 35 as the arrow 39 schematically. However, the translation of the slide 25 into its housing is done by maintaining a seal which prevents the air thus sucked from penetrating inside the drawer 25 and to penetrate inside the rest of the battery pack 20. For example the device 36 obstructs the drawer housing by following the bottom of the drawer 25 during translation.

Referring to Figure 5b, the translation of the drawer in its housing continues. A plate 37 can be provided on the upper face of the slide 25 which makes it possible to conceal the orifice 31 during the extraction of the slide.

FIG. 5c shows an end of opening of the drawer 25. The drawer is open in abutment in its housing so that the bottom of the drawer tightly obstructs the orifice 31 which constitutes the light discharge of the clarifier, for example by means of the device 36. This sealed obstruction is intended to prevent the air coming from outside can not cross the orifice 31 and penetrate inside the battery pack 20 by this opening.

Figure 5d shows a beginning of removal of absorbent material when the drawer is in abutment stop. The absorbent material 34, in the form of a layer, a bag or the like, is progressively removed from the drawer 25 by translation and over the cover 45 of the drawer. By this translation, a slight depression can appear at the bottom of the drawer, can suck the outside air inside the drawer by the clearance between the drawer and its housing. The bottom of the drawer obstructing the evacuation outlet of the clarifier tightly, the air coming from the outside by this way, can not penetrate inside the battery pack 20 by crossing the orifice 31 constituting this light.

Referring to Figures 5e and 5f, as the absorbent material 34 is removed from the drawer 25, the air from the outside gradually takes its place by depression at the bottom of the drawer but without being able to cross the discharge light of the decanter 32 and therefore unable to penetrate inside the battery pack 20.

FIG. 5g shows a possible variant embodiment in which a translational shrinkage of the absorbent material 34 releases an obstruction valve 33 of the drawer driven by a return spring which plates the valve 33 in leaktight manner against the lower part of the drawer 25. This valve 33 allows to allow air coming from outside, the passage through the clearance between the drawer 25 and its housing.

FIG. 6 shows a state of the battery pack 20 in which the absorbent material 34 is completely removed from the drawer 25. In the case of implementation of the variant previously explained with reference to FIG. valve 33 is pressed by the return spring against the lower part of the slide 25 and closes tightly.

Figures 7a to 7h illustrate a kinematic installation of the absorbent material 34 replacement followed by a reclosing of the drawer.

Referring to Figure 7a, the used absorbent material is replaced by a new material, inserted by translation within the drawer up to a first top wall 41 of the drawer. In the case of implementation of the embodiment variant for which the passage is sealed by the valve 33 pressed by the return spring against the lower part of the drawer, the absorbent material 34 is introduced against the valve.

As illustrated in FIG. 7b, the further insertion of the absorbent material 34 by translation inside the drawer 25 opens the valve 33 against its return spring, releasing the passage to the absorbent material 34 towards the bottom of the drawer 25.

FIG. 7c shows how the absorbent material 34 is pushed in translation inside and towards the bottom of the drawer 25. The bottom of the drawer, for example by means of the device 36, still closes the orifice 31 constituting the light in a sealed manner. evacuation of the decanter. The air occupying the volume of the bottom of the drawer 25 can not escape inside the battery pack 20 through the orifice 31. In order not to oppose the penetration of the absorbent material in the drawer, the air is driven out of the drawer 25, as the arrow 43 schematically, by the associated light 42 and the clearance between the drawer and its housing by the slight compression thus exerted by the translation of the absorbent material within the bottom of the drawer.

FIG. 7d shows the continuation of the insertion of the absorbent material 34 inside and towards the bottom of the drawer 25. The accentuation of the compression continues the expulsion of the air occupying the volume of the bottom of the drawer, towards the outside of the drawer and the battery pack 20.

In FIG. 7e, practically all the absorbent material 34 is inserted inside and at the bottom of the drawer 25. Almost all the air initially found in the drawer and inserted therein during the removal of the previous absorbent material 34, was expelled.

In FIG. 7f, the absorbent material is completely and perfectly inserted inside and at the bottom of the drawer 25 from which all the air has been expelled.

Referring to Figure 7g, the reclosing of the slide 25 flushes by the lower light 35 the air which had been introduced to the rear of the drawer 25 by this passage during its previous opening.

As shown in FIG. 7h, the end of the reclosing of the spool 25 completes expelling the air through the lower lumen 35. The spool 25 and the battery pack 20 are then found in a state similar to that shown in FIG. with a regenerated absorbent material.

In terms of industrial applicability, the invention makes it possible to manage both the condensates and the pressure differential internally of a refrigerated battery by a refrigerant loop. Management is implemented by preserving the seal from the outside to the inside of the battery pack and vice versa, without compromising the safety, dependability and durability of the battery. Thermal exchange performance is ensured at a negligible cost, both in terms of battery price and cost in warranty and after sales.

Claims

A sealed high voltage battery pack (20) for a hybrid or electric vehicle, comprising a housing (50) in which cells (23) are arranged for the production, storage and release of electrical energy, and an extractable reservoir ( 25) which contains a material (34) absorbing moisture, characterized in that it comprises means (22, 37, 36) for maintaining the seal inside the housing when extracting the extractable reservoir ( 25), in that it comprises a housing for the extractable reservoir (25) disposed at the bottom of the housing (50), said housing comprising a decanter wall (32) in which at least one orifice (31) is formed which allows a condensed liquid to flow to the absorber material (34) contained in the extractable reservoir (25), in that the extractable reservoir is in the form of a slide (25) and in that the holding means sealing comprise at least one sealing device (36) disposed on the bottom of the tank (25) so as to obstruct the housing when the slide (25) is brought into its extracted position, and in that said device (36) is arranged to obstruct the orifice (31) when the reservoir (25) is in the extracted position of the battery pack.

2. Battery pack according to claim 1, characterized in that the means for maintaining the seal comprise on at least one face (28) of the housing of the battery pack (20), one or more soft zones (22) which deform in order to balance pressures inside and outside the battery pack.

3. Battery pack according to claim 2, characterized in that said face (28) is in the upper part of the battery pack.

4. Battery pack according to one of the preceding claims, characterized in that the means for maintaining one sealing comprises at least one plate (37) on one side of the tank (25) in contact with said settler wall (32). ), said plate (37) being arranged to obscure the orifice (31) during extraction of the reservoir (25).

5. Battery pack according to one of the preceding claims, characterized in that said housing comprises an opening (35) which allows to balance pressures inside and outside the housing during extraction of the reservoir ( 25).

6. Battery pack according to one of the preceding claims, characterized in that it comprises a compartment (27) separate cells (23) dedicated to the maintenance of the battery pack (20).

7. Battery pack according to one of the preceding claims, characterized in that it comprises an obstruction valve (33) of the extractable reservoir driven by a return spring which is released by a withdrawal of the absorbent material (34) of in order to press the valve (33) tightly against a lower part of the extractable tank (25).