EP3114725A1

EP3114725A1 - Passive temperature control of rechargeable batteries

Info

Publication number: EP3114725A1
Application number: EP15714159.9A
Authority: EP
Inventors: Cornelia Neidl-Stippler; Hans Kunstwadl; Gerhard Mitic
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-01-15
Filing date: 2015-01-09
Publication date: 2017-01-11
Also published as: DE102014100420A1; SG10201806044YA; SG11201605831WA; WO2015107106A1; WO2015106758A1; JP2017503330A; WO2015106758A4; KR20160120293A

Abstract

The invention relates to a battery or rechargeable battery (8) comprising at least one battery cell (1, 1A,1B,1C,1D,1E) and a temperature control for the battery cells (1, 1A, 1B, 1C, 1D, 1E). The temperature control has: at least one vapour chamber (2, 2A, 2B), a first battery contact surface (4) of which is in direct contact with the surface of the at least one battery cell (1,1A, 1B, 1C, 1D, 1E); and heat pipes (10) which lie partially on a second heat pipe contact surface (4) of the vapour chamber (2, 2A, 2B) and lead out of the battery (8) to a heat exchanger (20).

Description

Passive temperature control of accumulators

The invention relates to a battery with a temperature control.

It is common today to use batteries (accumulators) for the caching of electrical energy for needs. Typical applications are home batteries,

Emergency batteries, but especially hybrid vehicles and electric vehicles, including rail vehicles and aircraft.

Batteries have optimal operating temperature ranges and it is known that the

Battery power at low temperature decreases sharply and at elevated temperature possible decomposition of the battery, including fire / oxidation can occur.

In order to set an optimal working temperature range for such batteries, various solutions are proposed.

JP3050051 discloses an air conditioner for electric vehicles, wherein the cooling or

Heating of the battery can be done via air cooling.

JP3733682 teaches a battery temperature control device which is a

Vehicle drive battery in a battery case by introducing air for

Car interior air system used in the battery case, can cool or heat housed via an inlet duct ..

Japanese Patent Application (Kokai) No. 10-32021 discloses a battery having a heat-insulating material, and the use of an auxiliary heater such as an electric heater to maintain a suitable working temperature of the battery in the cold.

Japanese Laid-Open Patent Publication (Kokai) No. 2006-269426 discloses a battery having a plurality of battery units, in which partition walls are disposed side by side between the battery units, a housing in which the battery units and the partition wall are installed, and an inlet and an outlet through which Heat carrier flows, and a PTC heating element between the partition and the battery unit

DAIMLER proposes for this purpose in DE 102010013025 heat transfer plates, the Connected to heat pipes, which quickly remove the heat from the battery

out transport.

DE 102012220873 A1 also recommends the use of heat pipes for rapid heat removal from the battery. To this end, the Zahnradfabrik Friedrichshafen uses flat heat pipes or vapor chambers, which absorb the heat of the battery cells in a planar manner and deliver this heat to their end faces on collectors. It has also been tried to store the waste heat of batteries for later use in heat accumulators (JP2001236145A and DE102011105366 A1)

The previous heat control of batteries could be improved.

Technical problem

It is an object of the invention to improve the previous thermal control of batteries and in particular to avoid the loss of heat energy within a system that uses the battery.

The object is achieved by a battery assembly with the features of claim 1. Advantageous developments emerge from the

dependent claims.

A generic battery or accumulator, has at least one battery cell and a temperature control for the battery cells, wherein the temperature control:

at least one vapor chamber, which is in direct contact with the surface of the at least one battery cell with a first battery contact surface, and heat pipes, which are partially disposed on a second heat pipe contacting surface of the vapor chamber and lead out of the battery to a heat exchanger.

As a result of this passive heat control, heat can be led out of the battery very quickly if necessary, and overheating of the same during charging or due to leakage currents in the case of material defects can be avoided. This is particularly useful for Li cells, as they can easily ignite and lead to fires. Some spectacular accidents involving these battery types in electric cars, laptops, and other mobile devices have made these major security bps. To be subjected to air traffic. Since chemical reactions responsible for the battery fires are exothermic and require heat of reaction, rapid heat dissipation of these batteries can increase their safety. It is also known that batteries generally have a working temperature range in which they operate optimally. Therefore, it makes sense to do this within the desired

Temperature range.

According to the invention, the heat absorption surface of the vapor chamber is arranged between two battery cells of a battery and to this purpose for optimal

Heat transfer adapted. For example. For example, the heat pipe contact surface of the Vapor Chamber can have recesses to accommodate the heat pipe inner sections to provide a larger heat transfer area between the heat pipe and the vapor chamber with better heat transfer.

The selection of the heat pipes is possible for those skilled in the field of heat pipes due to its expertise according to the requirements (explosion safety and / or high efficiency and / or legal requirements and spatial conditions) without inventive step and they can be selected from thermosyphon, heat pipes, variable Conductance heat pipes, loop heat pipes, also thermosyphon loops and capillary pumped loops (CPL), with the outer heatpipe section in the

Heat exchanger extends and the Wärmeleitrohrinnenabschnitt between the battery cells is performed on the Vapor Chambers.

In a simple embodiment of the invention, which cools only the battery cells, the Wärmeleitrohrinnenabschnitt is carried out as a condensation zone and the Wärmeleitrohraussen- section as the evaporation zone in the heat exchanger for heating the battery cells.

It is useful that the vapor chamber is at least partially made of electrically non-conductive material and is preferably designed as an electrical insulator between the Vaporchamber contact portion and the Vaporchamberwärme Ieitrohrkontaktfläche to avoid leakage currents.

In the temperature control system, an external heat exchanger for warming up or warming the battery cells is preferably used to control the battery temperature

Optimized performance of the same provided and the heat exchange medium is selected from: fluid materials, air, coolant from the coolant circuit, PCMs or a solid heat storage material comprising zeolite, salt hydrates or phase change material, comprising paraffins and fatty acids, are provided and the at least one heat tube, which is thermally connected to the battery at one end via the Vapor Chamber, which heats the battery via the Vapor Chamber as a heating device and / or can operate as a cooling device that heats the battery via the Vapor Chamber.

Depending on the use of the battery - whether mobile in vehicles of all kinds - weight and space requirements - or as a stationary battery in permanent or temporary structures, tent cities, as a backup battery, etc. - it is possible to select suitable heat conduction devices.

The at least one battery cell may be selected from rectangular columnar battery cells, laminated battery cells, and cylindrical battery cells.

In many applications, the Wärmeleitrohraussenabschnitte are connected to Wärmeleitblechen that allow rapid and large heat dissipation from the surface.

Depending on the requirements, it is also possible to use different heat pipes - both in terms of the working medium and the design.

According to the invention, planar heat pipes - also called vapor chambers or heat spreaders - are arranged between the battery cells, which locally dissipate locally occurring heat peaks over their area. Vapor Chambers are significantly faster and more efficient than classic heatsinks, whose thermal conductivity easily increases around them

Outperform hundreds of times and thus enable extremely fast heat distribution and, together with the heat pipes, also lead into and out of the battery.

On at least one surface of the vapor chambers heat pipes are arranged in intimate thermal contact. The surface structure of the Vapor Chamber can be designed so that it surrounds the heat pipes on three sides and thus allows a good heat transfer.

Outside the battery, the heat pipes pass through a heat accumulator, preferably a latent heat accumulator, which receives the latent heat of the working fluid of the heat pipes. It may be beneficial to use loop heat pipes, which have great heat transport capabilities.

A heat pipe type is selected so that it removes heat from a certain initial temperature of the battery cells from the battery and at least one heat conduction The tube type is selected to return heat from the heat storage to the battery via the heat spreader at a predetermined minimum temperature of the battery. By the two types of heatpipe, a battery temperature range can be adjusted and overheating and overcooling of the battery can be avoided. As a result, an increased life of the battery is achieved and their capacity is used optimally.

As latent heat storage solid storage, such as zeolites, can be used, the heat release is easily controlled. However, it is also fluid Latentwärmespeicherflüssigkeiten be used, which are performed in a battery independent circuit - eg. A heating circuit. The use of latent heat storage depends on its capacity and - in mobile use of the battery - and its weight. By way of example, but not by way of limitation, substances are to be named for

Salt water eutectics = 0 ° C - paraffins -30 ° C - 130 ° C - salt hydrates 5 ° C-130 ° C - sugar alcohols 90 ° C-180 ° C - salts and their eutectic mixtures logo CNRS logo INIST 180 ° C and mobile latent heat storage (macro-encapsulated) with a phase change material. Melting point of 58 ° C, inlet temperature of 56 ° C-180 ° C

Latent heat storage are known and are already used for a variety of technical applications, such as house heating or motor vehicles. With regard to the latent heat storage is fully contained in the book published on the Internet: http: //www.bueh~der-synergie.de/c new html / c 10 07 e .store thermal. htm - "Book of Synergy" by Ahmed A.W. Khammas, Rukn-eddin, al-Buti Bldg., Damascus / Syria P.O. Box 2361.

Known are bpsw. The slurries of microencapsulated phase change materials (PCM) as liquid latent storage media (see "slurry as a heat-transfer fluid Yasushi Yamagishi ^{1 *} , Hiromi Takeuchi ² , Alexander T. Pyatenko ² , Naoyuki Kayukawa ³ AIChE Journal Volume 45, issue 4, pages 696-707, April 1999. Such materials are commercially available, inter alia, from BASF SE under the trademark MIKRONAL® The heat can also be stored in hydrated salt crystals - for example, hydrated Na 2 SO 4, chlorides, hydrates, fluorides, etc

With regard to the application in mobile systems, these have been used in motor vehicles since 1993 (Car Tech) with salts that liquefy already at 78 ° C. Other applications in vehicles are the Latentwärmespeicher used by Modine Längerer & Reich since 1997, the salts which melts at 70 ° C - by water heated by the engine, which flows through the LWS - as in a car radiator - in tubes. At the When the cooled engine starts, the cooling water flows through the LWS, the salt crystallizes, and the released heat is immediately used for the heating. Another company, the VW subsidiary Votex, since 1997 offers such heat storage as retrofitting Possibility for the Golf and the Passat. These latent heat accumulators can be easily connected to vehicle batteries.

Since heat pipes have the property to be able to transport heat bidirectionally, heat can also be transferred back from the latent heat storage - for example, to maintain a suitable working temperature for the battery.

It is also possible to use loop heat pipes, some of which run outside the battery and have a very large heat transfer capacity.

In a case where a heat pipe is used as a heat-conducting member, the working fluid may be, for example, water, ammonia, carbon dioxide, ammonia and propane, alcohol or methanol or i-propanol or mixtures thereof, this list is merely exemplary and the Invention is by no means limited thereto. Taking into account the performance and effect on the global environment, water, and alcohols and possibly mixtures thereof are preferred as working fluid of the heat pipes for mobile applications.

If required, the heat pipes can retrieve heat from the latent heat storage and also release heat there. In a preferred embodiment, the latent heat storage may be a fluid latent heat storage, such as a micro-encapsulated phase change material (PCM), which can be used at various points of a vehicle and can be promoted there - for example, for heating or for heating an internal combustion engine Reduce emissions and consumption during cold start, to support heating etc.

Thus, a problem-free connection to an existing Kühlmittelytem or Tempe- rierfluidsystem done and the heat of the PCM be used where it is needed.

Preferably, the geometric arrangement of the heat pipes takes place so that gravity supports their function. The invention will be explained with reference to the accompanying drawing, in which schematically embodiments are illustrated. The invention is by no means limited to these and the examples are given purely by way of example for better understanding. It shows:

Fig. 1 is a schematic view of thermally conductive applied to a vapor chamber heat pipes in plan view;

Fig. 2 is a schematic view of a cross section through the vapor chamber of Fig.1;

Fig. 3 is a schematic representation of a heat pipe;

4 is a schematic cross-sectional view of a vapor chamber;

5 schematically shows a section through a battery along the vapor chamber according to FIG. 1 with heat conducting plates connected to the upper region of the heat pipe, which are surrounded by a heat removal medium;

6 schematically shows a section through a rechargeable battery along the vapor chamber according to FIG. 1 with a cooling fluid heat exchanger connected to the upper region of the heat conducting tube, which is flushed through by a cooling fluid; and

Fig. 7 shows schematically an arrangement similar to Fig. 6 with connected

Latent heat storage.

The invention will be described in more detail below with reference to the drawing.

Fig. 1 is a schematic view of a heat transfer unit according to the invention, consisting of a vapor chamber and thereon - as shown in FIG. 2 - in thermal contact applied heat pipes (10). One recognizes the Vapor Chamber (20), which ensures an exceptionally fast heat distribution over its entire surface. This heat is absorbed by on the surface of the vapor chamber (20) thermally connected heat pipes (10) and transported at the end outside the battery. On the Wärmeleitrohraussenabschnitt (5) can be mounted in a conventional manner Wärmeleitbleche (so-called. Fins), which are lapped by a heat-storing fluid, such as air or other gas and thus cooled. It is also possible to use this fluid for heating the battery during cold start, if it is then available tempered. Heat pipes work bidirectionally - that is, the heat transfer direction is reversed when the heat pipe outer portion (5) is warmer than the heat pipe inner portion (3) on the vapor chamber (2, 2A, 2B) and thus uniformly heats the vapor chamber due to its high heat dissipation capability. Thus, local overheating - for example, when charging the battery, which can lead to battery / battery damage to the fire, can be avoided.

Clearly in Fig. 3, the course of the working medium in the heat pipe (10) can be seen. It is heated at Wärmeleitrohrinnenabschnitt (3), occurs under latent heat absorption in the gas phase and condenses at the upper Wärmeleitrohrraussenussabschnitt (5) with the release of latent heat, which is taken from the connected there to the pipe wall Wärmeleitblechen and to a heat transfer medium - here with a thin thin Arrows shown - delivered and immediately removed. Thus, due to the extremely high heat conduction of the heat pipes (10) amounts of heat can be quickly removed from the battery cells (1, 1A, 1B, AC, 1D, 1E) and battery failure can be avoided. ,

Batteries usually include a plurality of battery cells (1, 1A, 1B, AC, 1D, 1E) that are regularly arranged. These battery cells are interconnected to a battery or accumulator.

Such an arrangement is shown in FIG. 5 on a vapor chamber (FIGS. 2, 2A, 2B). The heat pipe (10) absorbs heat from the vapor chamber surface (4), heats with it a liquid which passes under the absorption of latent heat in the gaseous state and transports the vapor to its outer end (5) with baffles, the then be traversed by a heat transfer fluid, which is gaseous or liquid. In conventional heat pipes, so-called. Thermosyphon, the liquid return is done only by gravity. In conventional heat pipes there is still a wick-like material in the pipe - the so-called Wiek- usually a sintered body, scrim / Gerwirke or molded channels, which due to capillary action and nucleation again effectively leads the liquefied liquid back into the hot area of the heat pipes and bumps on the Wärmeleitrohroberfläche avoids .. Therefore, heat pipes work with Wieks very effective. Another embodiment is Loop-Heatipes, which return as a closed loop the cooled gas as a liquid. Regarding possible heat pipes / heatpipes to avoid repetition to the book by David Reay and Peter Kew "Heat Pipes Theory, Design and Applications, 5th edition, Butterworth Heinemann - Verlag 2006, to which reference is made in full.

Fig. 6 shows the use of the inventive heat transfer element in a battery or accumulator attached thereto Wärmeleitfluidleitung. It can be clearly seen that the heat pipes (IO) run vertically and end in a fluid line used as a heat exchanger, for example for water. The water flows through the heat exchanger (20) with the arranged therein. Wärmeleitrohreaussenabschnitten, cools them and can then be used as warm water for heating the car or dissipate the heat in a conventional manner in the radiator, if it is connected to the cooling fluid line.

Fig. 7 shows schematically an embodiment with latent heat storage. The Wärmeleit rohraußenabschnitte (5) transfer their heat to a latent heat storage unit (20) -. For example, zeolite, but also paraffins and other latent heat storage, such as acetates and other salts. The thus charged heat storage can also be liquid and belong to a latent storage fluid circuit.

LIST OF REFERENCE NUMBERS

1, 1A, 1B, 1C, 1D, 1E battery cell

2, 2A, 2B Vapor Chamber

3 Wärmeleitrohrinnenabschnitt

4 Vapor Chamber contact section

5 Wärmeleitrohraussenabschnitt

7 electrically insulating section of the Vapor Chamber

8 battery or accumulator

10 heat pipe

20 heat exchangers

Heat transfer medium flow

Working fluid in Vapor Chamber heat flow

Claims

claims

1. Battery or accumulator (8), with

- At least one battery cell (1, 1A, 1B, 1C, 1D, 1E) and

a temperature control for the battery cells (1, 1A, 1B, 1C, 1D, 1E), characterized in that

the temperature control:

- At least one vapor chamber (2, 2A, 2B), with a first

Battery contact surface (4) directly to the surface of the at least one

Battery cell (1, 1A, 1B, 1C, 1D, 1E) is in contact and

Heat pipes (10) partially arranged on a second heat pipe contacting surface (4) of the vapor chamber (2, 2A, 2B) and leading out of the battery (8) to a heat exchanger (20),

having.

2. Battery according to claim 1, characterized in that the

Heat receiving surface (4) of the vapor chamber (2, 2A, 2B) between two battery cells (1 - 1A, 1B - 1C, 1D - 1E) of a battery (8) is arranged and adapted to this.

3. Battery according to one of the preceding claims, characterized in that the Wärmeleitrohrkontaktoberfläche (4) of the vapor chamber (2, 2A, 2B) recesses for receiving the Wärmeleitrohrinnenabschnitte (3) ..

4. Battery according to one of the preceding claims, characterized in that the heat pipes (10) are selected from thermosyphon, Wärmeleitrohrs, variable Conductance heat pipes, loop heat pipe (loop heatpipes), also

Thermosiphon loops and capillary pumped loops (CPL), wherein the heat pipe outer portion (5) in the heat exchanger (20) and the Wärmeleitrohrinnenabschnitt (3) between the battery cells (1, 1A, 1B, 1C, 1D , 1E) on the vapor chambers (2, 2A, 2B).

5. Battery according to one of claims 1 to 4, characterized in that the Wärmeleitrohrinnenabschnitt (3) as the condensation zone and the

Wärmeleitrohraussenabschnitt (5) as an evaporation zone in the heat exchanger (20) for heating the battery cells (1, 1A, 1 B, 1C, 1D, 1E) are executed.

6. Battery according to one of the preceding claims, characterized in that the vapor chamber (2, 2A, 2B) is at least partially made of electrically non-conductive material and preferably as an electrical insulator (7) between the Vacuumchamber contact portion (4) and Vacuumchamberwärmeleit- pipe contact surface (5) is provided.

7. Battery according to one of the preceding claims, wherein as the temperature control system an external heat exchanger (20) for warming or warming the battery cells (1, 1a ...) for the purpose of regulating the battery temperature for optimizing the same performance is provided and the heat exchange medium is selected from: fluid Materials, air, coolant from the coolant circuit, PCKs or a solid heat storage material comprising zeolite, salt hydrates or phase change material, comprising paraffins and fatty acids are provided and the at least one heat pipe which is thermally connected at one end via the vapor chamber to the battery, as Heating device heats the battery via the vapor chamber and / or can work as a cooling device that warms the battery through the vapor chamber.

8. A battery according to claim 1, which is equipped with a single battery cell or a plurality of aligned arranged battery cells, wherein the heat-conducting element between adjacent battery cells is arranged.

9. The battery according to claim 8, wherein the at least one battery cell is selected from rectangular columnar battery cells, laminated battery cells and cylindrical battery cells.

10. Battery according to one of the preceding claims, characterized in that the Wärmeleitrohraussenabschnitte are connected to Wärmeleitblechen.

11. Battery according to one of the preceding claims, characterized in that different heat pipes are used.