DE102016121838A1 - Temperature control element for a battery - Google Patents

Abstract

A tempering element (10) for a battery (16) has at least one coolant channel (24) in the inner region, which is designed to allow cooling by a cooling fluid. The tempering element (10) has at least one PTC heating element (44) in the inner region, which PTC heating element (44) is designed to heat the tempering element (10), and the tempering element (10) has a first base surface (51), which is provided for heat transfer between the temperature control element (10) and at least one battery module (14) of the battery (16). A battery (16) has such a tempering element (10).

Description

The invention relates to a tempering for a battery.

Batteries, as used, for example, for driving electric vehicles, are usually constructed from a plurality of battery modules, which in turn consist of a plurality of battery cells. Neither too high nor too low temperatures are favorable for the operation of the battery, and extreme temperatures can lead to reduced performance and also to a shortened service life.

It is known to arrange the battery modules for cooling on a common cooling plate in order to allow cooling by a fluid flowing through the cooling plate. The battery modules can also stand individually on a cooling plate.

It is also known to heat the cooling fluid at low temperatures in order to bring about heating of the cooling plate and thus also heating of the battery modules.

The CN 205211893 U shows a heating arrangement for a battery module. On an outer side of the heating arrangement heating elements are provided.

The US 2014/0050964 A1 , the US 2014/0287293 A1 , the CN 105070976 A and the CN 204857904 U show heating elements which are arranged between individual battery cells.

The US 2006/0210868 A1 , the US 2013/0280564 A1 and the CN 102832425 A show the temperature of a battery through a cooling fluid.

It is an object of the invention to provide a new tempering.

This object is achieved by the subject matter of claim 1.

The integration of the PTC heating element allows for improved heat transfer of the heat generated by the PTC heating element to the battery modules. In addition, the integration space and weight can be reduced by the integration. The arrangement of the PTC heating elements enables a higher heating power in the area of the battery modules.

According to a preferred embodiment, at least one PTC heating element on at least two sides of this at least one PTC heating element coolant channels are provided. This allows an arrangement of the PTC heating elements in an inner region of the tempering and thus a more uniform heating than in an arrangement in the edge region, which is also possible.

According to a preferred embodiment, the coolant channels extend in a first depth region of the tempering element, and the at least one PTC heating element extends in a second depth region of the tempering element. In this case, the first depth range and the second depth range overlap at least partially. This allows a space-saving arrangement of the PTC heating elements and coolant channels, and the tempering can be made flat.

According to a preferred embodiment, the first base is formed by a plate. As a result, the battery modules can be easily arranged on the first base.

According to a preferred embodiment, a plastic cover is provided on the side facing away from the first base surface second base to effect thermal insulation. When heating with the heating elements, a significantly better utilization of the heating power can be achieved.

According to a preferred embodiment, at least two battery modules are arranged on the first base, preferably at least three battery modules. The tempering is well suited for heating a plurality of battery modules, for example, for at least 10 or at least 20 battery modules.

According to a preferred embodiment, the PTC heating element is glued into the tempering. This results in a good connection, even between difficult connection partners.

According to a preferred embodiment, at least 10 PTC heating elements are provided, preferably at least 20 PTC heating elements. It thus achieves a uniform heating of the battery modules.

According to a preferred embodiment, a heat exchanger is provided between the PTC heating element and the first base area in order to effect a better heat distribution in the tempering element. This heat exchanger is preferably formed flat.

According to a preferred embodiment, the heat exchanger is formed as a planar ceramic component to effect an electrical insulation between the PTC heating element and the base.

According to a preferred embodiment, the heat exchanger is designed as a metal plate, for example made of copper or a copper alloy.

According to a preferred embodiment, the tempering is formed flat. This allows a good utilization of the thermal power of the PTC heating elements.

According to a preferred embodiment, the tempering has at least three PTC heating elements, which are not arranged on a straight line. The PTC heating elements are thus arranged flat, and thereby a more uniform heating of the tempering can be achieved.

According to a preferred embodiment, a molded part is provided, which at least partially forms the at least one coolant channel, and which identifies a recess in which the PTC heating element is arranged.

According to a preferred embodiment, a battery has a tempering element, and the battery is configured to use both the at least one PTC heating element and a discharge of the battery for heating. The combination has allowed for better thermal performance than was foreseeable with the individual processes.

Further details and advantageous developments of the invention will become apparent from the following described and illustrated in the drawings, in no way as a limitation of the invention to be understood embodiments, and from the dependent claims.

• 1 eine raumbildliche Darstellung des Temperierelements,
• 2 in einem Schnitt entlang der Schnittlinie II-II von 1 das Temperierelement mit schematisch angedeuteter Batterie,
• 3 in schematischer Darstellung das Temperierelement mit darauf angeordneten Batteriemodulen,
• 4 eine Messung der Temperatur in Abhängigkeit von der Zeit,
• 5 ein Messdiagramm der Temperatur in Abhängigkeit von der Zeit,
• 6 ein Messdiagramm der Aufwärmzeit in Abhängigkeit von der Umgebungstemperatur,
• 7 ein Messdiagramm der Leistungsaufnahme in Abhängigkeit von der Zeit,
• 8 ein Diagramm des ohmschen Widerstands eines Heizelements in Abhängigkeit von der Temperatur, und
• 9 ein Messdiagramm der Temperatur am Heizelement in Abhängigkeit von der Zeit.

It shows

• 1 a spatial representation of the tempering,
• 2 in a section along the section line II-II of 1 the tempering element with schematically indicated battery,
• 3 a schematic representation of the tempering with arranged thereon battery modules,
• 4 a measurement of the temperature as a function of time,
• 5 a measurement diagram of the temperature as a function of time,
• 6 a measurement diagram of the warm-up time as a function of the ambient temperature,
• 7 a measurement diagram of the power consumption as a function of time,
• 8th a diagram of the ohmic resistance of a heating element as a function of the temperature, and
• 9 a measurement diagram of the temperature at the heating element as a function of time.

Identical or equivalent parts are denoted by the same reference numerals in the various figures and usually described only once. This also applies to the properties assigned to the parts.

1 shows a heating element 10 in spatial representation, and 2 shows a section through the heating element 10 from 1 , Additionally are in 2 schematically the location of a battery module 14 and a battery case 12 a battery 16 shown. Such batteries 16 for vehicles are also referred to as traction batteries, and they are usually high-voltage batteries. The batteries 16 Usually also contain electronics that are responsible for controlling the charge, discharge and compliance with the physical boundary conditions for the battery 16 is trained.

The tempering element 10 has a coolant connection 21 and a coolant port 22 , via which a coolant (cooling fluid), for example, from the coolant connection 21 through the tempering 10 to the coolant connection 22 can flow to a cooling of the tempering 10 and thus the battery modules 14 to effect. An electrical connection 31 is at the tempering element 10 intended.

The tempering element 10 is flat, and so it allows the arrangement of a plurality of battery modules 14 at Temperierelement 10 , You can also use a tempering plate 10 speak.

The tempering element 10 has a first floor space 51 and one of the first page 51 opposite second base 52 , The first floor space 51 is designed to be the battery modules 14 at this position, to transfer heat between the battery modules 14 and the tempering 10 to enable.

To form the first base 51 has the tempering element 10 preferably a plate 41 , Inside the tempering element 10 are coolant channels 24 provided to allow passage of a cooling fluid. The coolant channels 24 are preferred by a molding 48 formed, but they can also be formed with hoses. Inside the tempering element 10 is a PTC heating element 44 intended. The molding preferably forms 48 the at least one coolant channel 24 at least in some areas, and the molding 48 has a recess in which the PTC heating element 44 is arranged. The molding 48 is preferably formed of a metal or a plastic, wherein the material is preferably good thermal conductivity.

It is preferred between the PTC heating element 44 and the plate 41 a heat exchanger 42 intended. As a heat exchanger 42 For example, a ceramic component can be provided in order to effect an electrical insulation in addition to the better and areal heat distribution. In this case, a ceramic component that is so large that it can be used for several PTC heating elements 44 acts, or it can affect any or all of the PTC heating elements 44 be assigned. Between the PTC heating element 44 and the heat exchanger 42 Can additionally a contact plate 43 be provided. The second floor space 52 of the tempering 10 is preferred by a second plate 46 educated. The second plate 46 is preferably a plastic component, so that it can serve as a plastic cover. This leads to a better thermal insulation of the tempering 10 outward. While such a thermal insulation in a pure cooling plate without heating element would be unnecessary and even negative because of the reduced cooling capacity, it leads to a significant shortening of the heating time and thus to an advantageous embodiment when using the PTC heating elements.

It can be seen that the coolant channels 24 in a first depth region of the tempering element 10 extend, and that the at least one PTC heating element 44 in a second depth range of the tempering element 10 extends, wherein the first depth range and the second depth range overlap at least partially. In other words, the coolant channels 24 and the PTC heating elements 44 at least partially arranged in the same depth range. This allows a good utilization of the geometry of the tempering 10 , And it can be formed with a comparatively small thickness. You could also say that the PTC heating elements 44 and the coolant channels 24 at least partially arranged side by side.

The PTC heating element 44 is preferably in the tempering 10 glued to ensure a secure mechanical connection. However, it can also be inserted or jammed, for example.

Tests were carried out, as were many PTC heating elements 44 in the tempering 10 are advantageous. In particular, it was examined whether with the available number of PTC heating elements a uniform heating of the battery modules 14 is achievable. From a number of 10 PTC heating elements 44 could a sufficiently even heating of the battery modules 14 be achieved with 20 or more PTC heating elements 44 could a good uniform heating of the battery modules 14 on the tempering 10 be achieved.

Tests with a preferred battery module have shown that the optimum temperature was in the range of 15 ° C and 45 ° C, in the range above 45 ° C and in the range between -2 ° C and 15 ° C, the performance of the battery is reduced and the Operation is possible only with restrictions, and in the range below -2 ° C only one discharge is possible. Depending on the battery module used, these limits may vary slightly. At a battery temperature below 0 ° C, no electric driving and charging is allowed, at best in emergency situations.

3 shows the tempering 10 with 26 battery modules arranged thereon 14 , For example, two 13-inch modules from Samsung SDI can be used. The coolant connection 21 is via at least one coolant channel 24 with the coolant connection 22 By branching and then merging, both the left and right battery modules are connected 14 cooled when a coolant flows through the coolant channels. The coolant channel 24 could also be in the tempering 10 meandering back and forth to achieve a large-scale cooling.

Preference is given to the PTC heating elements 44 at least partially arranged such that on at least two of its sides coolant channels 24 are provided. This allows an arrangement of the PTC heating elements 44 in the inner area and a compact construction.

The PTC heating elements 44 are arranged flat, so not only at one point or in a straight line. In other words, the tempering element has 10 at least three PTC heating elements, which are not arranged on a straight line. In tests, when the PTC heating elements are arranged in a straight line, it has been shown that the battery modules 14 be heated very unevenly, as areas that are a greater distance from the PTC heating elements 44 have less heat than nearby areas. Due to the flat arrangement of the PTC heating elements, a more uniform heating can be achieved.

The electrical connection 31 is via lines 32 with the PTC heating elements 44 electrically connected to by means of a connection of the electrical connection 31 heating the temperature control element with a current or voltage source 10 and thus also the battery modules 14 to effect.

4 shows a measurement diagram of the temperature T at the battery modules 14 depending on the time t. The line 101 shows the temperature increase caused by a controlled discharge of the battery modules 14 is achievable. The temperature rises over the course of 2,000 seconds from -20 ° C to about -15 ° C. When heating by discharge is exploited that the battery modules 14 generate heat during a discharge and thus virtually heat itself. The line 102 shows the temperature at one of the battery modules 14 when heating with the help of PTC heating elements 44 , The heating was done with a rated output of 600 W PTC heating elements, and the temperature increases from -20 ° C to approximately 25 ° C within 2,000 seconds. It is thus a high heating speed achievable.

The line 103 shows a combination of heating by means of the PTC heating elements 44 and additionally by means of discharge. The heating rate can be further increased with this combination of measures, and the final temperature is about 35 ° C.

Overall, can be with the help of the tempering 10 reach a high heating rate. This becomes clear when comparing with the previously used method, in which the coolant 45 It had to be heated for a few minutes with an electrical power of 1.3 kW to increase the temperature from -20 ° C to 0 ° C. This is attributed to the fact that in the previous method by the heated coolant in addition components are heated outside the battery, so that the heat energy has served only a small part of the heating of the battery. In addition, the coolant circuit must be activated. The integration of the PTC heating element 44 in the tempering 10 also allows weight savings, since no additional housing for an external PTC heating element must be provided. An exemplary PTC heater, outside the tempering 10 is arranged, weighs 2.6 kg and requires a space of 71 x 195 x 207 mm ³ .

Measurements of the spread of the heating times of the battery modules were carried out. It has been shown that the vertical spread of the heating times is comparatively low, and the vertical temperature gradients usually move in a range smaller than 5 K. However, the horizontal spread of the heating times is comparatively large. In place of the ceramic component 42 For example, a metallic component made of a good heat-conducting metal can be used.

5 shows a measurement diagram accordingly 4 , which was started at a starting temperature of -10 ° C. The line 111 shows the heating that can be achieved by discharging,
the line 112 the heating by the tempering 10 , and the line 113 the heating in a combination of the tempering 10 and the discharge. This combination according to line 113 has proved to be very advantageous, since in particular at the beginning of heating, a large increase in temperature by the tempering 10 achievable and then the effect of unloading comes more to the fore. In addition, the combination of the heating method has the advantage that the maximum allowable discharge current and thus the heating power are dependent on the temperature of the battery modules 14 , Because of this by the tempering 10 can be heated with the discharge current can be increased earlier, and the combination of heating by the tempering 10 and discharging leads to a better result than was foreseeable.

6 shows a measurement diagram in which the time taken to increase the temperature on the battery module 14 is required by 10 K, depending on the ambient temperature is shown. The line 121 shows the time required for a heating element with a nominal power of 300 W, and the line 122 was measured with a heating element with a rated power of 600 W. The warm-up time τ ₁₀ increases with increasing temperature.

7 shows a measurement diagram in which the electrical power consumption P through the PTC heating element 44 is shown as a function of time t. The line 131 shows the measurement at a nominal power of 300 W, and the line 132 shows the measurement at a rated power of 600 W. At the line 131 the measurement was started at an ambient temperature of -10 ° C, and at the line 132 at an ambient temperature of -20 ° C.

It can be seen that the power consumption is greater at low temperatures than at high temperatures. The nominal power is available only a few seconds after the start of heating.

8th shows a characteristic of the electrical resistance R of a PTC heating element 44 as a function of the temperature T at the PTC heating element 44 , The electrical resistance R is plotted logarithmically, and it increases sharply from an initial temperature T _{A of} the PTC behavior with increasing temperature. A temperature T _E is plotted as the end temperature of the PTC behavior, and between the initial temperature T _A and the final temperature T _E , a temperature T _{N is} entered at which the resistance rises sharply. The maximum surface temperature at the PTC heating element 44 in this embodiment is 80 ° C. This behavior of PTC heating elements 44 is beneficial because overheating due to the sharp increase the resistance of the PTC heating element 44 is prevented.

9 shows a measurement diagram for the temperature at the tempering 10 during a long-term warm-up. The starting temperature was -10 ° C, and an increase in temperature of 10 K occurred after 990 seconds. An increase in temperature of 20 K has occurred after 2378 seconds and a maximum temperature T _max of 69 ° C has been reached. Overheating is thus avoided and this is an advantageous safety aspect of the solution. The growth constant k has the value 2.9 · 10 ^-4 1 / s.

Naturally, many modifications and modifications are possible within the scope of the present invention.

The experiments were carried out with battery modules from Samsung SDI with an electrical charge of 37 Ah, but other battery modules can also be used.

It has been shown in experiments that PTC heating elements are well suited for applications where much heat energy must be provided.

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

• CN 205211893 U [0005]
• US 2014/0050964 A1 [0006]
• US 2014/0287293 A1 [0006]
• CN 105070976 A [0006]
• CN 204857904 U [0006]
• US 2006/0210868 A1 [0007]
• US 2013/0280564 A1 [0007]
• CN 102832425 A [0007]

Claims (15)

Tempering element (10) for a battery (16), which tempering element (10) has at least one coolant channel (24) in the interior region, which is adapted to allow cooling by a cooling fluid, which tempering element (10) has at least one PTC heating element (44) in the interior region, which PTC heating element (44) is designed to heat the temperature control element (10), and which tempering element (10) has a first base area (51) which is provided for heat transfer between the tempering element (10) and at least one battery module (14) of the battery (16). Tempering element (10) after Claim 1 in which a coolant channel (24) is provided on at least one PTC heating element (44) on at least two sides of this at least one PTC heating element (44). Tempering element (10) after Claim 1 or 2 in which the at least one coolant channel (24) extends in a first depth region of the tempering element (10), in which the at least one PTC heating element (44) extends in a second depth region of the tempering element (10), the first depth region and the second depth range overlap at least partially. Temperature control element (10) according to any one of the preceding claims, wherein the first base surface (51) by a plate (41) is formed. Tempering element (10) according to one of the preceding claims, wherein on the first base surface (51) facing away from the second base surface (52), a plastic cover (46) is provided to effect a thermal insulation. Temperature control element (10) according to one of the preceding claims, wherein at least two battery modules (14) are arranged on the first base surface (51), preferably at least three battery modules (14). Temperature control element (10) according to one of the preceding claims, wherein the PTC heating element (44) is glued into the temperature control element (10). Temperature control element (10) according to one of the preceding claims, wherein at least 10 PTC heating elements (44) are provided, preferably at least 20 PTC heating elements (44). Temperature control element (10) according to one of the preceding claims, wherein between the PTC heating element (44) and the first base surface (51), a heat exchanger (42) is provided to effect a better heat distribution in the tempering (10). Tempering element (10) after Claim 9 in which the heat exchanger (42) is designed as a planar ceramic component (42) in order to effect an electrical insulation between the PTC heating element (44) and the base surface (51). Tempering element (10) after Claim 9 or 10 in which the heat exchanger (42) is formed as a metal plate. Tempering element (10) according to one of the preceding claims, which has a planar design Temperature control element (10) according to one of the preceding claims, which has at least three PTC heating elements (44) which are not arranged on a straight line. Tempering element (10) according to any one of the preceding claims, which has a molded part (48), the molding (48) the at least one coolant channel (24) at least partially formed, and which molded part (48) has a recess in which the PTC heating element (44) is arranged. Battery (16) with a tempering element (10) according to one of the preceding claims, which battery (16) is adapted to use for heating both the at least one PTC heating element (44) and a discharge of the battery (16).

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