WO2013053653A2

WO2013053653A2 - Battery system, method for reducing the moisture in the drying agent of the drying device of a battery system, motor vehicle, and method for operating a motor vehicle

Info

Publication number: WO2013053653A2
Application number: PCT/EP2012/069773
Authority: WO
Inventors: Markus Kohlberger; Johannes BIEDERT
Original assignee: Robert Bosch Gmbh; Samsung Sdi Co., Ltd.
Priority date: 2011-10-12
Filing date: 2012-10-05
Publication date: 2013-04-18
Also published as: DE102011084351A1; WO2013053653A3

Abstract

The present invention relates to a battery system which comprises at least one battery cell, in particular a lithium-ion battery cell, and also a drying device for reducing the moisture in gas, in particular in air, wherein the drying device comprises drying agent (31) with which water can be absorbed from gas. The invention makes provision for the dying device to have a heating device (60) with which the moisture in the drying agent (31) can be reduced. The present invention also relates to a method for reducing the moisture in the drying agent (31) of the drying device of a battery system, and also to a motor vehicle and to a method for operating a motor vehicle.

Description

description

title

Batteriesvstem, method for reducing the moisture of the desiccant of the drying device of a battery system, motor vehicle and method for operating a motor vehicle

The present invention relates to a battery system and a method for

Reduction of the moisture of the desiccant of the drying device of a battery system.

Furthermore, the present invention relates to a motor vehicle and a method for operating a motor vehicle.

In this case, the present invention is particularly related to a lithium-ion battery system or lithium-ion batteries or corresponding battery cell modules.

State of the art

There is a considerable demand for batteries for a wide range of applications, such as vehicles, stationary equipment such as wind turbines, and mobile electronic equipment such as laptops and communication equipment. These batteries are very high demands in terms of reliability, durability and performance.

Predestined for a wide range of applications is the

Lithium-ion technology. It is characterized among other things by high energy density and extremely low self-discharge. Such lithium-ion cells usually comprise an electrode which

Lithium-ion can store reversibly in the course of the so-called intercalation or can outsource again in the course of so-called deintercalation. The intercalation takes place during the charging process of the battery cell, and deintercalation takes place during the discharge of the battery cell for the power supply of electrical units.

It is becoming apparent that in the future both in stationary applications such as wind turbines, in vehicles such as in hybrid and

Electric vehicles as well as in the consumer area, here for example in laptops and mobile telephones, new battery systems will be used, at the very high

Requirements with regard to reliability, performance and service life.

To ensure the safety of lithium-ion battery modules as well as to optimize battery performance and lifetime, the battery cells

optimally operate within a defined temperature range.

Especially at high power consumption or power output must

Heating the battery cells are avoided over a certain operating temperature and operationally occurring heat dissipated. To this

Purpose usually cooling systems are used.

For cooling the battery modules usually air or water is used as the medium, wherein the respective medium absorbs the heat and dissipates from the cells. Aqueous cooling media are often passed through a bottom plate, which is thermally connected, for example via sheets with the battery cells. When using air as a cooling medium, this is between the cells

passed. In particular, in the case of air cooling, a relatively high outlay for preparation with regard to dehumidification and filtering of the cooling air as well as the flow guidance through the housing to the battery cells is necessary. In a water-cooled battery system in particular the problem of

Condensation within the housing.

Battery cells are usually housed in a battery cell housing, which protects the battery cells from mechanical stress and should continue to serve isolation from the environment. The problem with this is that a hermetically sealed housing in particular by pressure differences, which weather conditions as well as due to different geodetic heights can occur during use of the battery cells, is heavily loaded. With a longer service life, the penetration of moisture into the housing can not be prevented. For sealing the housing used sealing membranes, as used for example in control units or headlamps are often permeable to water vapor, which can condense when cooling the battery cells, so that in the housing there is a risk of short circuit or at least insulation faults and corrosion.

In order to reduce moisture or condensation occurring in the housing, the air in the housing can alternatively or additionally be dried by means of desiccant. Thus, e.g. not

DE 102010028861 discloses a drying device for reducing the humidity of a gas in a battery housing interior, wherein the

Drying device comprises a desiccant body.

Disclosure of the invention

According to the invention, a battery system is provided, which

at least one battery cell, in particular a lithium-ion battery cell, comprises, as well as a drying device for reducing the moisture of gas, in particular of air, wherein the drying device comprises desiccant, with which water from gas can be accommodated. It is provided according to the invention that the drying device has a heating device with which the moisture of the drying agent can be reduced.

As a result, the desiccant can be regenerated so that it can be used to further absorb water from the gas, such. B. from the ambient air of a battery is ready. A complex replacement of the desiccant is thereby avoidable. A constant pressure equalization remains guaranteed.

With the moisture in this case the water content in the desiccant is called. The desiccant is preferably in a so-called desiccant cartridge

housed and may be a silica gel or a molecular sieve. The heater is advantageously arranged directly on or in the desiccant or separated only by the wall of the desiccant cartridge from the desiccant.

Preferably, the battery system further comprises a housing in which the

Battery cell is arranged, and one between the desiccant and the

Moisture barrier arranged battery cell, with which it is preventable that the desiccant dispensed or released by the desiccant during heating for

Battery cell arrives.

The moisture barrier can z. B. a valve or even a membrane that is permeable to air with a maximum humidity of 40%.

The position of the moisture barrier between the desiccant and the battery cell refers to a position in a possible gas volume flow between the desiccant and the battery cell.

In a favorable embodiment, the moisture barrier can be activated.

The activation can z. B. in certain time intervals automatically or regulated as a function of moisture saturation degree.

For this purpose, the drying device may comprise a measuring device or a sensor with which the moisture of the TM can be determined. By means of a control or regulating device, which may be part of a battery management system, can be on detection of an inadmissible saturation of the desiccant with moisture start the heater and simultaneously or at least promptly activate the moisture barrier, so that the desiccant heated moisture not Battery cell can get. An advantageous position of the moisture barrier is in a nozzle in or on the housing, which forms the pressure equalization opening.

Advantageously, the battery system comprises a pressure equalization opening, wherein the drying device is arranged in the pressure equalization opening. The pressure compensation opening may be part of the housing. The

Drying device and the pressure compensation opening should be designed such that the drying device closes the pressure equalization opening. Preferably, the battery system further comprises a

Gas flow generating device for generating a gas volume flow.

As a result, a safe and effective dissipation of the moist gas produced during desiccant heating is ensured by the drying device. Such gas flow generating device may, for. B. a fan or a

Absauginrichtung be.

Alternatively or additionally, the battery system may comprise an air conditioning system with which the gas heated by the desiccant can be cooled, so that the water content present in this gas is at least partially condensed. The thus dried gas can be dissipated to the ambient air.

This device has the advantage that, due to the pressure gradient from the desiccant to the air conditioning system, it is possible to generate a gas volume flow which removes the desiccant and thus also the battery cell and thus keep the relatively humid air blown out by the desiccant away from the battery cell. The air conditioner may be the air conditioning system provided in a motor vehicle for air conditioning of the passenger compartment.

Another aspect of the invention is a method for reducing the

Moisture of the desiccant of the drying device of a battery system according to the invention, in which desiccant is supplied by the heating means heat, so that the moisture of the desiccant is reduced. Preferably, the heater is electrically operated.

In an energetically favorable embodiment of the method for reducing the moisture of the desiccant, the energy for operating the heating device is not provided directly by the battery cell. That is, it is preferably provided that the energy of other aggregates or supply systems is used to dry the desiccant, such as. B. the waste heat of an external heating, the waste heat from power electronics such. As shooters and / or Vorladewiderständen, and electrical energy from charging stations or recuperation. In the last-mentioned embodiment, the electrical energy obtained by means of recuperation is preferred in the

Heater used that can not be fed into the battery cell.

However, it should not be ruled out that the heating device can be operated with electrical energy that is provided directly by the battery cell or a plurality of battery cells.

In the preferred application of the battery system according to the invention or the inventive method for reducing the moisture of the drying agent of the drying device of the battery system in a motor vehicle, in particular in an electric or so-called plug-in hybrid vehicle, the

Drying of the drying agent according to the invention can be realized, if the

Battery system is connected to an external charging station for charging, so that the supplied electrical energy is used to heat the desiccant.

Furthermore, the method can be carried out such that the gas heated by the desiccant is cooled by means of an air conditioner, so that the water content present in this gas is at least partially condensed.

This means that the air conditioning system is used as a cold trap. The thus dried gas can be dissipated to the ambient air. The resulting condensate can be discharged to the environment.

This drying operation can also be realized during the connection of the battery system to an external charging station.

In addition, according to the invention, a motor vehicle is provided, which in particular can be a motor vehicle which can be driven by an electric motor and which has at least one battery system according to the invention. According to the invention, this motor vehicle is operable such that kinetic energy of the motor vehicle is converted into electrical energy and used to heat the desiccant.

In particular, after reaching a preliminary highest geodetic altitude, z. B. after crossing a mountain pass and subsequent descent, it is assumed that the gas pressure in the housing increases. The kinetic energy released when the geodetic height is reduced, that is to say when driving downhill, can be converted into electrical energy in a recuperation device of the motor vehicle and this can be used for heating the desiccant, in particular for periodic heating.

Alternatively or additionally, the drying can be realized when an air conditioner of the vehicle is active and thus serves as a cold trap for the gas heated by the desiccant.

drawings

Embodiments of the invention will be with reference to the drawing and the

explained in more detail below description.

It shows:

1 shows a battery system according to the invention in a schematic view.

This battery system comprises a housing 10, in which at least one battery cell, not shown, is arranged. The housing 10 is by means of a

gas-permeable line connected to a desiccant cartridge 30, is arranged in the desiccant 31. Between the housing 10 and the

Desiccant cartridge 30, a moisture barrier 20 is arranged, which may be a membrane or a valve. This membrane or valve is designed to be permeable only to gases having a humidity of less than 40%.

The moisture barrier 20 may also be configured such that it controllably and / or controllably allows or prevents a gas volume flow. Possibly This control and / or regulation can take place automatically, preferably via a battery management system.

In normal operation, the desiccant 31 is thus in fluid communication with the gas volume in the housing 10, so that water contained in the gas in the housing 10 can be absorbed by the desiccant 31. If it is determined that the moisture of the desiccant 31 exceeds a certain value, such as 60%, the heater 60 is actuated, so that by means of the heat generated by the heater 60, the desiccant 31 is baked. In this case, the moisture barrier 20 either automatically prevents flow of the relatively humid, unheated gas from the desiccant 31 into the housing 10, or the moisture barrier 20 is controlled by a control and / or regulating circuit to deliver a gas volume flow from the desiccant 31 into the housing 10 Housing 10 prevents.

The activation of the heating device 60 can take place on the basis of the determination of exceeding the limit value of the moisture content of the desiccant 31 by means of a sensor, or at certain time intervals.

Preferably, the heater 60 is electrically powered, such as by the illustrated power source 61. It does not necessarily have its own

It may be provided that the battery cell in the housing 10 serves as an energy source for the heater 60 or that an external power source, such as an external power connector, for charging the battery of an electric vehicle as Energy source serves.

Alternatively or additionally, it can be provided that the energy source is not electric, but the waste heat of an aggregate arranged in the vicinity of the desiccant cartridge 30, such as, for example, waste heat from power electronics, is used to heat the desiccant.

In a further embodiment, the energy source 61 can also be a

Rekuperationseinrichtung be that converts kinetic energy of the vehicle into electrical energy when using the battery system in an electric vehicle, so that at least part of this electrical energy is used to heat the

Desiccant 31 can be used.

The desiccant cartridge 31 is preferably arranged in a pressure equalization opening of the housing 10 or at such an opening. This ensures that due to pressure differences in the housing 10th

incoming air is dried by the desiccant 31, and that a sufficient pressure equalization is realized, so that seals of the housing 10 are subject to a lower load.

The battery system may further be additionally configured with an air conditioning system 40 which, when the battery system is used in an electric vehicle, may in particular be the air conditioning system of this vehicle. By the air conditioner 40 can be cooled by the drying agent 31 relatively humid and warm gas, so that the water content of the gas is condensed. This leads to a decrease in pressure of the gas, so that due to the pressure gradient between the

Desiccant 31 and the air conditioner 40, a gas flow is generated, which is directed away from the desiccant cartridge 30 and thus causes the heated gas flows through the outlet 50 into the environment.

Alternatively or additionally, a gas flow generating device 51 may be provided, with which a gas volume flow can be generated, which is also of the

Desiccant cartridge 30 is directed toward the outlet 50. In this case, the location of the arrangement of the gas flow generating device 51 is not limited to the position shown in the figure, but such

Gas flow generating device 51 may, especially if it is designed as a fan, also much further upstream in the present invention

Battery system can be arranged.

Claims

claims

1 . Battery system, comprising at least one battery cell, in particular a

Lithium-ion battery cell, and a drying device for reducing the moisture of gas, in particular of air, wherein the drying device

Desiccant (31) comprises, with which water is absorbable from gas, characterized

in that the drying device has a heating device (60) with which the moisture of the desiccant (31) can be reduced.

2. Battery system according to claim 1, comprising a housing (10), in which the

Battery cell is arranged, as well as between the desiccant (31) and the battery cell arranged moisture barrier (20), with which is preventable that the desiccant (31) can be dispensed or released during heating

Moisture reaches the battery cell.

3. Battery system according to claim 2, wherein the moisture barrier (20) is activated.

4. Battery system according to one of the preceding claims, which a

Compression orifice comprises, wherein the drying device in the

Pressure compensation opening is arranged.

5. Battery system according to one of the preceding claims, further comprising a gas flow generating means (51) for generating a

Gas volume flow.

6. Method for reducing the moisture of the desiccant (31) of

A drying system of a battery system according to any one of claims 1 to 5, wherein heat is supplied to the desiccant (31) by means of the heater (60) so that the moisture of the desiccant (31) is reduced.

A method for reducing the moisture of the desiccant (31) of claim 6, wherein the energy for operating the heater (60) is not provided directly by the battery cell.

8. A method for reducing the moisture of the desiccant (31) according to any one of claims 6 and 7, wherein the heated by the desiccant (31) gas is cooled by means of an air conditioner, so that the present in this gas water content is at least partially condensed.

9. Motor vehicle, in particular an electric motor driven motor vehicle,

comprising at least one battery system according to one of claims 1 to 5.

10. A method of operating a motor vehicle according to claim 9, wherein

kinetic energy of the motor vehicle is converted into electrical energy and used to heat the desiccant (31).