DE102013214998A1 - Device and method for temperature control of battery cells and battery system - Google Patents

Abstract

Apparatus for controlling the temperature of a battery system (10) by means of a temperature control means (130) comprising a temperature sensor means (220) for detecting measurements of the temperature outside the battery system (10), a humidity sensor means (2301, 2302) or condensation sensitive insulation resistance measuring means (240) for detecting Measuring values of the humidity, a processing device (210) for evaluating the detected measured values and determining the temperature of the temperature control means (130), and an adjusting device (250) for adjusting the temperature of the temperature control means (130), a battery system, a vehicle, a method Computer program and a computer program product.

Description

The invention relates to a device and a method for controlling the temperature of battery cells, a battery system with a battery cell, in particular a lithium-ion cell, and a computer program and a computer program product. The invention further relates to a vehicle, in particular a motor vehicle such as electric motor vehicle or hybrid vehicle, with the battery system.

State of the art

It is foreseeable that both in stationary applications, for example in wind turbines, and in mobile applications, for example in electric vehicles (EV) or hybrid vehicles (hybrid electric vehicles, HEV), as rechargeable energy storage increasingly new battery systems, for example with lithium-ion batteries or nickel-metal hybrid batteries will be used.

The battery systems must meet very high requirements in terms of usable energy content, charge / discharge efficiency, reliability, life and unwanted capacity loss due to frequent partial discharge.

A battery system includes a plurality of battery cells. When used to drive vehicles, the battery system may include, for example, about 100 battery cells. Due to their internal cell resistance, the battery cells heat up during charging and discharging.

The permissible for the operation of the battery cells temperature range is typically between -30 ° C and + 70 ° C. In the lower range of the operating temperature, the performance of the battery cells can be significantly reduced. In this case, an irreversible damage to the battery cells can occur. Even if the operating temperature is exceeded, the performance of the battery cells may decrease significantly. In this case, an irreversible damage to the battery cells can also occur. The damage can lead to an accelerated aging of the battery cells or a thermal runaway of the battery cells, which represents a danger to humans and the environment.

In order to ensure the safety and function of the battery system, it is therefore necessary to operate the battery cells within the predetermined temperature range. On the one hand, heat is generated during operation of the battery cells, which must be dissipated in order to prevent the battery cells from heating up above the critical maximum temperature. On the other hand, it may be necessary to heat the battery cells at low temperatures to a minimum temperature. To maintain the predetermined temperature range, the battery system is heated, d. H. cooled or heated as needed.

For this purpose, the battery system may comprise a fluid, for example a liquid such as alcohol, for example propane-1,2,3-triol (glycerol, glycerol), oil or water or a liquid mixture, as a temperature control agent in a temperature control medium circuit.

If a housing of the battery system is not hermetically sealed (gas-tight), moisture, for example in the form of water vapor, can constantly penetrate into the battery system, for example through seals. Since the tempering agent temperature is significantly lower than the temperature in the housing during cooling of the battery system, condensate (condensed water, condensation water) may form. Thus, in the battery system, water can form and / or accumulate in liquid form, either pure or as a liquid mixture. Liquid water, for example raindrops, mist droplets and solid water, for example ice and snow crystals, are not included in the humidity.

The battery systems, however, like all electrical, electronic or information technology devices in general, are very sensitive to the presence of fluids in liquid form, for example liquids such as water, as these, for example, short circuits, corrosion, electrochemical migration, damage can cause, or at least favor, insulation such as electrical insulation.

Out DE 10 2011 082 991 A1 A battery is already known, comprising a battery housing, tempering and a lithium-ion cell, which is in direct contact with one of the tempering.

Disclosure of the invention

Advantages of the invention

The devices and methods according to the invention with the features of the independent claims have the advantage that the humidity (relative humidity, relative humidity, RH) can be monitored and taken into account during the temperature control of a battery housing or battery system. As a result, damage to the battery system can be prevented by condensation and accelerated aging of the battery cells can be reduced by high temperatures. Furthermore, the requirements for the battery system with respect to the tightness can be reduced. This can reduce the weight of the battery system. Thus, for example, the costs Reduced manufacturing costs and operating costs and resources are saved.

The measures listed in the dependent claims advantageous developments and improvements of the independent claims specified devices and methods are possible.

Conveniently, the moisture sensor device can be arranged within the battery system. As a result, the moisture can be determined more accurately.

Conveniently, the moisture sensor device can be arranged outside the battery system. Thereby, the operating environment of the battery system can be more accurately considered.

Conveniently, at a low temperature outside the battery system, the temperature of the temperature control can be determined so that the temperature of the temperature control is above the temperature outside the battery system. As a result, the temperature-induced aging of the battery cells can be reduced.

Conveniently, at a high temperature outside the battery system and at a low humidity, the temperature of the temperature control be determined so that the temperature of the temperature control below the temperature outside the battery system and above a detected dew point temperature, wherein the determined dew point temperature of the determined humidity is dependent. As a result, the temperature-induced aging of the battery cells can be further reduced.

Appropriately, at a high temperature outside the battery system and at high humidity, the temperature of the temperature control can be determined so that the temperature of the temperature control is above the temperature outside the battery system and the dew point temperature.

Thereby, the condensation can be prevented by accepting a minimized temperature-induced aging of the battery cells.

Conveniently, the temperature of the temperature control can be changed gradually, increased or decreased. As a result, the reaction behavior of the device can be improved.

The invention provides a battery system comprising the device described above.

The invention further provides a vehicle, in particular motor vehicle such as electric motor vehicle, hybrid vehicle or electric motorcycle (electric bike, e-bike), electric bicycle (pedelec), a maritime vehicle such as electric boat, an aircraft or a spacecraft, ready, the previously described and with the Vehicle connected device or the previously described and connected to the vehicle battery system.

The invention further provides a computer program that performs all the steps of the previously described method when running on a computing device.

The invention further provides a computer program product with program code stored on a machine-readable medium for carrying out the method described above when the program code is executed on a computer or control unit.

It is within the scope of the invention not necessarily to carry out the method steps in the order described. In a further embodiment, the method steps can also be interleaved into one another.

Furthermore, it is possible that individual sections of the described method can be designed as individual salable units and remaining sections of the method as other salable units. Thus, the method according to the invention can be executed as a distributed system on different computer-based instances, for example client-server instances.

For example, it is possible for a module to include different sub-modules.

Brief description of the drawings

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.

Show it:

1 a schematic view of a battery system 10 according to an embodiment of the invention, and

2 a schematic representation of the outside temperature and temperature inside as a function of relative humidity in the battery system 10 according to the embodiment of the invention.

Embodiments of the invention

1 shows a schematic view of a battery system 10 according to an embodiment of the invention.

The battery system 10 includes a battery 100 and a device 200 for temperature control of the battery 100 ,

The battery 100 includes a battery case 105 and one, two, three or more battery cells 110 ₁ , 110 ₂ , in an interior of the battery case 105 are arranged. The battery cells 110 ₁ , 110 ₂ may be formed as primary cells or primary elements that are not rechargeable or as secondary cells that are rechargeable. The secondary cells may be formed, for example, as a lithium-ion battery (lithium battery, lithium-ion battery, Li-ion battery, Li-ion secondary battery) or lithium polymer battery (LiPoly battery, LiPo battery) , The battery 100 can also be a battery module for electrically connecting the battery cells 110 ₁ , 110 ₂ include (in 1 Not shown).

The battery 100 furthermore comprises a temperature control system, for example a temperature control system with a temperature control agent such as liquid temperature control 130 , The temperature control system can have one channel 120 for receiving the temperature control 130 , a first connection (flow) 125 ₁ , with a first end of the channel 120 is connected, for supplying the temperature control 130 and a second connection (return) 125 ₂ , with a second end of the channel 120 is connected to the removal of the temperature control 130 include. The tempering system can, as in 1 exemplified within the battery case 105 be arranged.

Alternatively, the tempering system wholly or partially, for example in the form of a cooling plate, which may be arranged below and / or between the battery cells, in the interior of the battery case 105 be arranged.The temperature control 130 may include a refrigerant, coolant or heating means. The temperature control agent 130 For example, a fluid such as a gas such as carbon dioxide or a gas mixture such as air or a liquid such as alcohol, for example, propane-1,2,3-triol (glycerol, glycerol), oil or water, or a liquid mixture.

In the interior of the battery case 105 can, for example, due to the battery cells 110 ₁ , 110 ₂ as heat sources and / or the temperature control 130 as heat sink give an inhomogeneous temperature distribution, so that different places in the interior of the battery case 105 may have different temperature values. Since the condensation will begin at the coolest point inside the battery case, the inside temperature may be the minimum temperature in the interior of the battery system 10 and / or the minimum temperature of the temperature control 130 (minimum internal temperature).

The device 200 for temperature control of the battery system 10 and / or reducing the cell-specific temperature-dependent aging comprises a temperature sensor device (temperature sensor, thermal sensor) 220 for acquiring measured values of temperature, a humidity sensor device (humidity sensor, humidity sensor) 230 ₁ , 230 ₂ and / or condensation-sensitive insulation resistance measuring device 240 for detecting measured values of the humidity, an adjusting device 250 for adjusting the temperature (flow temperature) of the temperature control 130 and a processing device 210 for evaluating the detected measured values and determining and regulating the flow temperature of the temperature control.

The temperature sensor device 220 is outside the battery case 105 and near the battery case 105 arranged and detects the temperature outside the battery case 105 (External temperature). The temperature sensor device 220 can on, for example, on the battery case 105 be attached.

The moisture sensor device 230 ₁ , 230 ₂ can be inside the battery case 105 be arranged and the humidity inside the battery case 105 capture, or the moisture sensor device 230 ₁ , 230 ₂ can be outside the battery case 105 and near the battery case 105 be arranged and the moisture outside the battery case 105 to capture. The moisture sensor device 230 ₁ , 230 ₂ can be in or on, for example, the battery case 105 be attached. Alternatively, the device 200 the moisture sensor device 230 ₁ as the first humidity sensor device and the humidity sensor device 230 ₂ as a second moisture sensor device. The temperature sensor device 220 and the humidity sensor device 230 ₁ , 230 ₂ may be arranged adjacent to each other. The tempering device 220 and the humidity sensor device 230 ₂ may be arranged together in a sensor device. The moisture sensor device 230 ₁ , 230 ₂ can be used as insulation resistance measuring device 240 be educated. The measurement of the insulation resistance of the battery system 10 Reacts sensitively to condensed moisture: The insulation resistance drops very sharply with increasing formation of condensation (condensation) and increases again with evaporation of the condensed water. For example, if the value of the insulation resistance is less than 2.5 MΩ drops, condensation forms, or the relative humidity is increased. Alternatively or additionally, an insulation resistance measuring device 240 of the battery system 10 be used to determine the humidity.

The processing device 210 evaluates the recorded measured values and determines the temperature of the temperature control medium from the evaluated measured values (temperature of the temperature control medium) 130 so that the formation of condensation inside the battery case 105 prevents or reduces and the temperature-related aging of the battery cells 110 ₁ , 110 _{2 is} reduced, for example minimized. In this case, the processing device takes into account 210 that the humidity inside the battery case 105 can condense only if the temperature within the battery case (internal temperature) or the temperature Temperiermitteltemperatur below the outdoor temperature or below the respective humidity-dependent dew-point temperature (condensation point temperature) is.

At a low outdoor temperature, for example in the range of -30 ° C to + 15 ° C, the processing equipment determines 210 the tempering agent temperature so that the internal temperature or minimum internal temperature is above the outside temperature. A condensation does not take place, and the temperature-induced aging of the battery cells 110 ₁ , 110 ₂ can be minimized.

At a high outside temperature, for example in the range of + 15 ° C to + 70 ° C, determines the processing device 210 the tempering agent temperature taking into account the humidity: At a low humidity, for example in the range of 0% to 45%, determines the processing device 210 the tempering agent temperature so that the internal temperature or minimum internal temperature is below the outside temperature and above or near the dew point temperature. Strong condensation and temperature-related aging of the battery cells 110 ₁ , 110 ₂ are prevented. At high humidity, for example in the range of 45% to 100%, the processing equipment determines 210 the tempering agent temperature so that the internal temperature or minimum internal temperature is definitely above the dew point temperature. The condensation is prevented, and the temperature-induced aging of the battery cells 110 ₁ , 110 ₂ is accepted. In other words, at the high outside temperature, the inside temperature is always above or near the dew point temperature. In this case, the internal temperature may be below the outside temperature, wherein the internal temperature may be above the outside temperature to prevent condensation or to dry the interior.

The processing device 210 can change the temperature of the temperature control medium, for example increase or decrease it.

The processing device 210 can be designed as an analog processing device or digital processing device. The processing device 210 can be a processor 2100 , a store 2200 and an interface 2300 include. The processing device 210 can be configured as a microcontroller, computing device (computer) or control unit (control unit) such as battery control unit (BCU). The processor 2100 can be designed as a microprocessor. The memory 2200 can be designed as a volatile and / or non-volatile memory. The memory 2200 used to store instructions (commands) 2210 , for example, instructions from an operating system and / or application program, and / or data 2220 , for example, measured values, parameters, range values, comparison values, tables such as dew point tables. the interface 2300 serves, for example, to transmit signals from the sensor devices 220 . 230 ₁ , 230 ₂ , 240 to the processing device 210 and from the processing device 210 to the adjusting device 250 and / or a (higher-level) control device. the interface 2300 may continue to transmit signals between the processing device 210 and a heater serve. The processor 2100 processes the data based on the stored instructions, so that the procedure for tempering the battery system 10 is implemented. The processing device 210 can, as in 1 shown outside the battery 100 be arranged. Alternatively, the processing device 210 in the battery 100 be arranged.

The device 200 for temperature control of the battery system 100 Furthermore, a detection device for detecting measured values of the temperature control system, for example the temperature of the temperature control 130 (Temperature of the temperature control).

The process for temperature control of the battery system 10 and / or reducing the cell-specific temperature-dependent aging comprises detecting measured values of the temperature outside the battery system 10 by means of a temperature sensor device 220 , detection of measured values of the humidity by means of a moisture sensor device 230 ₁ , 230 ₂ and / or a condensation-sensitive insulation resistance measuring device 240 , evaluating the detected measured values and determining and regulating the temperature of the temperature control means by means of a processing device 210 , and adjusting the temperature of the temperature control 130 by means of an adjusting device 250 , The capture The measured values of the humidity can be inside or outside the battery system 10 respectively.

The method may further include, at a low outside temperature, for example in the range of -30 ° C to + 15 ° C, determining the temperature of the temperature control means by the processing means 210 so that the internal temperature or minimum internal temperature is above the outside temperature.

The method may further include, at a high outside temperature, for example in the range of + 15 ° C to + 70 ° C, determining the temperature of the temperature control means by the processing means 210 taking into account the humidity.

The method may further comprise determining the dew point temperature from the detected measured values of the temperature and the humidity by means of the processing device 210 include.

The method may further include, at a low humidity, for example in the range of 0% to 45%, determining the temperature of the conditioning means by the processing means 210 such that the internal temperature or minimum internal temperature is below the outside temperature and above or near the dew point temperature. Depending on the robustness of the battery system 10 In the case of (very) low humidity, an internal temperature below the dew point may also be possible in relation to moisture.

The method may further include, at a high humidity, for example in the range of 45% to 100%, determining the temperature of the temperature control means by the processing means 210 such that the internal temperature is above the dew point temperature.

The method may further include stepwise changing, for example, increasing or decreasing, the temperature of the temperature-controlling means.

2 shows a schematic representation of the outside temperature and inside temperature as a function of the relative humidity in the battery system 10 according to the embodiment of the invention.

In the illustration, the outside temperature T _A in the range of -10 ° C to + 50 ° C horizontal (horizontal) is plotted, and the temperature of the battery cells 110 ₁ , 110 ₂ internal temperature T _I in the range of 0 ° C to 50 ° C vertical (vertical) applied. As already described above, the temperature range permissible for operation of the battery cells is, for example, between -15 ° C and + 70 ° C, preferably between 0 ° C and + 40 ° C, such as between + 18 ° C and + 25 ° C. A diagonal through the origin indicates points where the inside temperature equals the outside temperature. Furthermore, a number of degrees characterize the dew point temperatures as a function of the outside temperature with the relative humidity RH as a parameter.

For an outside temperature of T _A1 = + 35 ° C (high outside temperature) with a relative humidity rH ₁ = 80% (high air humidity) determines the processing device 210 for example, as internal temperature or minimum internal temperature above the outside temperature and above the corresponding dew point temperature of about + 31 ° C, a range of + 35 ° C to + 40 ° C.

For an outside temperature of T _A2 = + 40 ° C (high outside temperature) with a relative humidity rH ₂ = 30% (low air humidity) determines the processing device 210 for example, as internal temperature or minimum internal temperature below the outside temperature and above the corresponding dew point temperature of about + 19 ° C, a range of + 19 ° C to + 40 ° C.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011082991 A1 [0010]

Claims (12)

Device for tempering a battery system ( 10 ) by means of a temperature control agent ( 130 ), comprising: - a temperature sensor device ( 220 ) for acquiring measured values of the temperature outside the battery system ( 10 ), - a humidity sensor device ( 230 ₁ , 230 ₂ ) or condensation-sensitive insulation resistance measuring device ( 240 ) for acquiring measured values of the humidity, - a processing device ( 210 ) for evaluating the recorded measured values and determining the temperature of the temperature control means ( 130 ), and - an adjusting device ( 250 ) for adjusting the temperature of the temperature control ( 130 ). The device according to claim 1, wherein: - the humidity sensor device ( 230 ₁ , 230 ₂ ) within the battery system ( 10 ), or - the humidity sensor device ( 230 ₁ , 230 ₂ ) outside the battery system ( 10 ) is arranged. The device according to claim 1 or 2, wherein the processing device ( 210 ): - at a low temperature outside the battery system ( 10 ), the temperature of the temperature control ( 130 ) so that the temperature of the temperature control agent ( 130 ) above the temperature outside the battery system ( 10 ), - at a high temperature outside the battery system ( 10 ) and at a low humidity, the temperature of the temperature control ( 130 ) so that the temperature of the temperature control agent ( 130 ) below the temperature outside the battery system ( 10 ) and above a determined dew point temperature, wherein the determined dew point temperature is dependent on the determined moisture, or - at a high temperature outside the battery system ( 10 ) and at a high humidity, the temperature of the temperature control ( 130 ) so that the temperature of the temperature control agent ( 130 ) above the temperature outside the battery system ( 10 ) and the dew point temperature is. The device according to one of claims 1 to 3, wherein the processing device ( 210 ) is formed: - the temperature of the temperature control ( 130 ) to gradually change, increase or decrease. Battery system ( 10 ), comprising: - the device ( 200 ) according to one of claims 1 to 4. Vehicle, in particular motor vehicle such as electric motor vehicle or hybrid vehicle, comprising: - the device ( 200 ) according to one of claims 1 to 3 connected to the vehicle, or - the battery system ( 10 ) according to claim 5 connected to the vehicle. Method for controlling the temperature of a battery system ( 10 ) by means of a temperature control agent ( 130 ), comprising: - acquiring measured values of the temperature outside the battery system ( 10 ) by means of a temperature sensor device ( 220 ), - acquiring measured values of the humidity by means of a moisture sensor device ( 230 ₁ , 230 ₂ ) or condensation-sensitive insulation resistance measuring device ( 240 ), - evaluating the recorded measured values and determining the temperature of the temperature control medium ( 130 ) by means of a processing device ( 210 ), and - adjusting the temperature of the temperature control agent ( 130 ) by means of an adjusting device ( 250 ). The method of claim 7, wherein: - detecting the humidity readings within the battery system ( 10 ), or - the acquisition of the measured values of the moisture outside the battery system ( 10 ) he follows. The method of claim 7 or 8, wherein determining the temperature of the temperature control agent ( 130 ) comprises: - at a low temperature outside the battery system ( 10 ), Determining the temperature of the temperature control agent ( 130 ) so that the temperature of the temperature control ( 130 ) above the temperature outside the battery system ( 10 ), - at a high temperature outside the battery system ( 10 ) and at a low humidity, determining the temperature of the temperature control ( 130 ) so that the temperature of the temperature control ( 130 ) below the temperature outside the battery system ( 10 ) and above a determined dew point temperature, wherein the determined dew point temperature is dependent on the determined moisture, or - at a high temperature outside the battery system ( 10 ) and at a high humidity, determining the temperature of the temperature control ( 130 ) so that the temperature of the temperature control ( 130 ) above the temperature outside the battery system ( 10 ) and the dew point temperature is. The method according to any one of claims 7 to 9, further comprising: - stepwise changing, increasing or decreasing the temperature of the temperature control agent ( 130 ). Computer program stored on a data carrier or in a memory ( 2200 ) of a computer ( 210 ) and that of the computer ( 210 ) readable commands ( 2210 ), for carrying out the method according to one of the claims 7 to 10 are determined when the commands ( 2210 ) on the computer ( 210 ). Computer program product comprising the computer program according to claim 11.

Images