EP3607596A1

EP3607596A1 - Traction battery

Info

Publication number: EP3607596A1
Application number: EP18726723.2A
Authority: EP
Inventors: Heinrich Kesper
Original assignee: Hoppecke Batterien GmbH and Co KG
Current assignee: Hoppecke Batterien GmbH and Co KG
Priority date: 2017-04-04
Filing date: 2018-04-03
Publication date: 2020-02-12
Also published as: CN110476272B; DE102017107203B4; WO2018185074A1; US20210098840A1; DE102017107203A1; CN110476272A; US11196110B2

Abstract

The invention relates to a traction battery, comprising a plurality of battery cells (2) which are wired to one another and which each have positive and negative electrode plates arranged alternately with one another in a cell housing, and having a plurality of battery troughs (7), which each accommodate a plurality of battery cells (2) in series, each battery trough (7) is designed to be electrolyte-resistant and electrolyte-tight, and having a battery box (13) accommodating the battery troughs (7),wherein adjacent battery troughs (7) are arranged at a distance from one another, leaving a gap space (17), and wherein, underneath the battery troughs (7), a volume space is provided, which is in fluidic connection with the gap spaces (17) and is used as a distribution gap space (22) for all the gap spaces (17), and having a forcible flow system for a cooling medium, which has a means for generating a forcible flow, which is connected to the distributor gap space (22), for which purpose the distributor gap space (22) has at the inlet end (26) thereof a connection for a cooling medium feed line.

Description

traction battery

The invention relates to a traction battery with a plurality of interconnected battery cells, each having in a cell housing alternately arranged positive and negative electrode plates.

Traction batteries of the type described above are well known in the art, which is why it does not require a separate documentary proof at this point.

As non-stationary batteries, traction batteries typically find use in vehicle technology, for example in forklifts, lift trucks and / or the like. Previously known traction batteries have a plurality of battery cells electrically interconnected to one another. Depending on the desired output voltage, 12 cells (for 24 volts), 24 cells (for 48 volts) or 40 cells (for 80 volts) are typically used. In this case, each battery cell has a cell housing which accommodates on the one hand an electrolyte and on the other hand alternately arranged positive and negative electrode plates.

The cell housing of a battery cell is typically made of plastic and it is the upper side by means of a lid electrolyte sealed, for example by welding the lid to the housing.

To accommodate the battery cells, a traction battery has a battery tray. This is usually designed without covers in the manner of a box and has a bottom and four side walls arranged thereon. When the traction battery is ready for use, the battery tray holds the battery cells tightly packed. In this case, the battery cells are arranged in columns and rows in order to optimally utilize the space provided by the battery compartment.

The battery tray is usually formed from welded together steel sheets. It provides a base supporting the battery cells and four side walls welded thereto. In order to be able to counteract any tolerance-related inaccuracies, the receiving space provided by the battery tray is made somewhat larger in its clear internal dimensions than the overall dimensions of the cell package tight packed battery cells. This creates a circumferential compensation gap between the trough side walls on the one hand and the sibling battery cells of the battery cell package on the other hand. In this compensation gap spacer plates are used after insertion of the battery cells in the battery tray made of plastic, whereby the compensation gap closed and the battery cells are braced against each other and supported against the side walls of the battery trough. The thickness of these spacer plates is determined by the tolerance to be compensated.

Furthermore, battery arrangements have become known from the prior art which are designed as traction batteries which can not be handled separately. Such a battery assembly has become known, for example, from US 2014/0338999 A1, which relates to a floor assembly for an electric vehicle that houses a battery pack. This battery pack has a battery case made up of a battery tray and a battery cover. In the final assembled state, the battery tray and the battery cover are bolted together with the interposition of a sealing element. The thus formed battery case accommodates a plurality of battery modules, wherein each battery module includes a plurality of battery cells.

The battery tray, which forms the bottom of the battery case is made in two parts and has an upper plate and a lower plate, wherein the two plates are spaced apart to form a cooling channel.

Furthermore, a cooling device is provided which sucks air from outside the battery pack and conveys it into the cooling channel provided by the battery trough. The cooling channel provides a total of two flow paths, each U-shaped and are guided from the back of the bottom assembly to the front of the same and back again.

Traction batteries of the type described above have proven themselves in everyday practice. Nevertheless, there is a desire to improve, in particular to broaden the scope. It is therefore the object of the invention to provide a novel traction battery, which allows a wider range of applications. To achieve this object, the invention proposes a traction battery, with a plurality of interconnected battery cells, each having in a cell housing alternately arranged positive and negative electrode plates, and with a plurality of battery trays, each receiving a plurality of battery cells in series, wherein each battery tray electrolyte-resistant and -densit is formed, and with the battery trays receiving battery box, adjacent battery trays are spaced apart leaving a gap space, and wherein below the battery trays a volume space is provided, which communicates with the gap spaces in fluid communication and as Verteilerspaltraum for all Spaces serves, as well as with a forced flow system for a cooling medium having a means for generating a forced flow, which is connectable to the Verteilerspaltraum, for which purpose of the manifold Paltraum has at its inlet end a connection for a cooling medium supply line.

The basis of the invention is a traction battery with a plurality of interconnected battery cells, each having in a cell housing alternately arranged positive and negative electrode plates, and with several battery trays, each of which serves to receive a plurality of battery cells, each battery tray electrolyte-resistant and -dicht is formed, as well as with the battery trays receiving battery box, wherein adjacent battery trays are spaced apart leaving a gap space.

In contrast to the previous design according to the prior art, the embodiment of the invention no longer provides only a battery tray, which receives all the battery cells of the traction battery packed tightly. Rather, a plurality of battery trays are provided, which are received in the final assembled state of a common battery box. In this case, adjacent battery trays are spaced from each other, while leaving a gap.

Each of the battery trays receives a series of battery cells arranged one behind the other so that the configuration according to the invention requires that the battery cells are surrounded by a cooling medium, for example air, at least with regard to two sides.

The proposed due to the inventive design slits allow in the intended use heat removal by air circulation. Thus, the operating temperature can be kept at a low level compared to conventional compact cell pack. This in turn makes it possible to use the traction battery according to the invention without significant loss of life also for high current applications. Thanks to the embodiment of the invention, therefore, the scope is extended.

"High-current application" in the sense of the invention means the taking and / or delivery of high currents within short periods of time, be it in the case of discharge by the operation of, for example, three-phase motors or in loading by the use of, for example, modern charging management systems and / or

Energy recovery facilities (recuperation). The uptake and / or the delivery of high currents leads with increasing size of the individual battery cells to more significant and unavoidable undesirable side effects, such as the heat development due to the increasing internal cell resistance with increasing cell size. In a disadvantageous way, this leads to a shortened service life and to shorter discharge cycles in the case of use. Thus, from the prior art previously known traction batteries from a certain size for high current applications are not or only partially suitable, which is particularly true for traction batteries size, which are required in the market because of the desired high capacity. Thus, there is the conflicting need to create a battery that, while providing longevity, either provides high capacity or is suitable for high current applications. Generic batteries do not meet this requirement basically reason.

Investigations by the applicant have shown that prior art traction batteries can heat up to 60 ° C. and more, in particular during loading, in the case of high-current application, depending on the size and the associated internal resistance. Typically, however, prior art traction batteries are only for an average temperature level of e.g. 30 ° C designed. As a result, therefore, the high current application leads to a significant reduction in battery life due to the associated temperature stress.

For the purpose of battery conservation after the heating due to high current application by, for example, a loading process on the user side before Start a further high current application to provide a cooling phase. However, such a cooling phase can take several days, depending on the size and the temperature level reached, which is not only economically significant disadvantage, it must also be taken into account failure and changeover times and compensated by redundant facilities.

The embodiment according to the invention overcomes the disadvantages described above and also allows an application in the high-current range without significant shortening of the overall service life.

According to the invention, it is provided that the traction battery has a forced flow system for a cooling medium.

For the purposes of the present invention, this means that an air flow caused simply in the gap spaces due to the thermal conditions is not generated, ie a pure convection flow, but a forced flow is produced by fans, pumps or the like, so that the respective cooling medium, for example air through the cracks are pressed or sucked.

It is therefore proposed a traction battery, with a plurality of interconnected battery cells, each having in a cell housing alternately arranged positive and negative electrode plates, and with multiple battery trays, each receiving a plurality of battery cells, each battery tray is formed electrolyte-proof and -sealed , and with a battery box receiving the battery box, wherein adjacent battery trays are spaced apart leaving a gap space to each other and with a forced flow system for a cooling medium

Cooling media can be other than air, and they can be gaseous or liquid. Within the scope of the invention, they can be pre-tempered in order to be able to carry out targeted and controllable cooling cycles.

It is inventively provided below the battery trays a volume space. This volume space is in fluid communication with the gap spaces formed between adjacent battery trays. It's such a thing created coherent cooling medium space, which is composed of the gap formed between the battery trays on the one hand and the gap spaces fluidly interconnected volume space on the other hand. The space provided below the battery trays volume space serves as Verteilerspaltraum, for all fluidly connected thereto gap spaces. When used as intended cooling medium can thus be introduced into the Verteilerspaltraum, which then distributes from there to the fluidically connected thereto gap spaces.

It is further provided according to the invention a means for generating a forced flow. This means may be, for example, a fan that promotes ambient air as the cooling medium.

The means for generating a forced flow is connectable to the distribution gap space. For this purpose, it is provided that the distribution gap space has a connection for a cooling medium supply line at its inlet end. In the intended use case, therefore, can be effected by the means for generating a forced flow, a cooling medium supply line which passes through the provided at the inlet end of the Verteilerspaltraums connection in the Verteilerspaltraum and from there to the gaps between the battery trays. As a result, the battery trays and thus the battery cells received in series are washed around by the cooling medium both on the underside and in terms of their large sides. This results in an accelerated heat release as a result.

Instead of a coolant supply line, it is also possible to provide a coolant discharge, in which case no compressed air, but draft, is generated by means of a fan. In this case, there is a reverse flow path, according to the air is sucked through the upwardly open gap spaces, which then passes from there into the Verteilerspaltraum from which it is then sucked by means of the fan.

It is also proposed in this context, a system having a plurality of traction batteries of the type described above and a means for generating a forced flow of the type described above, wherein the traction batteries can optionally be fluidly connected to the means for generating a forced flow. Such a system allows one Having traction battery in its intended use, at the same time charged by a prior intended use traction battery and thereby cooled in the manner already described using the means for generating a forced flow. Thanks to the design according to the invention, the traction battery to be charged is available much earlier for intended use.

It can also be arranged directly in the field of fissures fans. It is also possible for a plurality of gap spaces to be fluidically connected to one another so that fans or pumps can be arranged at a suitable point.

According to a particularly advantageous proposal of the invention, a bottom gap space is formed on the bottom side. For this purpose, the battery box is provided with a double bottom, which is fluidly connected to the gap formed between the battery trays. Thus, it can serve according to the invention as a distributor gap space for distribution of the cooling medium over all gap spaces.

According to a further advantageous proposal of the invention, the bottom gap space or also another distribution gap space has different flow cross sections in the flow longitudinal direction. Thus, for example, it can be ensured that all other gap spaces connected to the respective gap space are uniformly exposed to cooling medium.

If one of the gap spaces is provided with an interface for the connection of an external flow source, it is proposed according to the invention that this be formed in a slot shape. In this case, the entire system comprises an externally connected to the battery box from the outside flow source, such as a fan.

Alternatively or additionally, fans may be arranged within the battery box at various suitable locations.

Due to the spaced arrangement of the battery trays a ventilation system is created, which allows cooling, for example by air circulation. On the one hand Thus, the temperature level achieved in the application can be reduced, but on the other hand, it is possible, above all, to allow cooling to be considerably shortened compared to the state of the art, which does not take days, but only a few hours. This advantage comes in particular after proper loading of a traction battery to fruition. On the one hand, because the cooling time after a designated loading process is significantly reduced, on the other hand also because the traction battery according to the invention in standard, conventional loading and unloading cycles can be integrated without the risk of permanent overheating, so that a significantly longer service life sets.

It is provided according to a preferred embodiment of the invention that the distribution gap space is bounded by a spaced apart from the battery trays bottom plate, as already described above. It is preferred to arrange spacers between the battery trays and the bottom plate. These spacers provide an exact spacing of the bottom plate to the undersides of the battery trays.

The spacers are preferably transverse to the longitudinal direction of the battery trays extending webs. These are, for example, welded to the underside of the battery trays. The bottom plate is in turn connected to the spacers, for example by welding. The side walls forming the battery box can be pulled down in the height direction so far that the bottom plate and the spacers are visually covered.

It is provided according to a further feature of the invention that the distributor gap space has a flow cross-section that continuously tapers from the inlet end to the opposite end. This embodiment has the advantage that, as a result of the coolant flowing out through the gap spaces between the battery trays connected to the distributor gap space, there is no pressure loss within the distributor gap space. It is therefore ensured by this construction that is conveyed in all to the distribution gap space fluidly connected fissure cooling medium with the same pressurization. It is provided according to a further feature of the invention that the means for generating a forced flow comprises a fan. This embodiment is particularly preferable when ambient air is used as the cooling medium.

The fan preferably has a housing. This housing is equipped according to a further feature of the invention with an outlet slot which is formed corresponding to the connection of the inlet-side end of the Verteilerspaltraums. In the case of cooling, the housing can be fluidly connected to the traction battery, so that the cooling air supplied by the fan can pass through the fan housing through the outlet slot and the distributor gap-side connection into the distributor gap space and the gap spaces fluidically connected thereto.

The fan has according to a further feature of the invention via a radial impeller. Thus, a radial fan is used. In this case, the advantage of a radial fan is in particular to be able to reliably generate a pressure build-up within the supplied cooling medium required for a desired cooling of the battery cells. In addition, results in a compact design, since the cooling air can be sucked at right angles to the direction of the outlet flow.

Alternatively to a radial fan to an axial fan, that is a fan with an axial impeller. An advantage of this embodiment is that by means of the fan also a suction can take place, in which case the cooling air is not pressed into the distribution gap space, but the air located there is sucked, so trailing air as the cooling air through the connected to the distribution gap space gap spaces Clearing rooms and the distribution gap space is led.

The embodiment of the invention serves in particular to effect a battery cell cooling when the traction battery is recharged after a previous discharge. Thus, during a charging process, cooling medium is introduced into the traction battery for the purpose of purging the battery trays so that heat is expelled, as a result of which the traction battery can be used more quickly after completing proper recharging. It is therefore proposed with the invention, a sensor that provides automatic switching on the means for generating a forced flow when the traction battery to the center is connected fluidically to produce a forced flow.

According to a first proposal, it is proposed in this context that proximity sensors be provided which detect a connection of the traction battery to the means for generating a forced flow. As soon as such a detection has taken place, that is to say a traction battery connected to the means for generating a forced flow is detected, an automatic activation of the means for generating a forced flow takes place. Such a sensor detection can also be combined with a time control, which makes it possible to obtain an automatic shutdown of the means for generating a forced flow when a predeterminable operating interval is completed.

Such a timing control may also provide an interval circuit, that is a repeated switching on and off of the means for generating a forced flow until it has come to a proper total cooling of the traction battery. Such an interval operation has the advantage that the overall efficiency of the system can be improved. Because the energy needed to cool a traction battery can be optimized.

According to an alternative embodiment, a sensor is provided, which is arranged on the charging cable between the charger and traction battery. This sensor detects a current flow through the charging cable, whereby an intervention of the means for generating a forced flow begins with the start of the actual charging process.

In this case, this current flow detection sensor is not located within the charging cable, but is mounted as a separately trained sensor from the outside to the charging cable. This has the advantage that a retrofit can easily follow for already existing inventory systems.

The battery trays according to the invention are formed electrolyte-resistant and -dicht. "Electrolyte-resistant" in the sense of the invention means that the inner surface of the battery trays is resistant to the chemical action of the electrolytes housed by the battery cells. "Electrolyte-tight" in the sense of the invention means that the electrolyte is safe from the battery tray in the event of leakage from a defective battery cell housing is not retained in the vicinity of the traction battery, provided, of course, the traction battery is aligned as intended and is not, for example, improperly tilted or even turned upside down.

With the embodiment according to the invention, the synergistic effect is achieved that, on the one hand, an air circulation between adjacent battery cells is permitted, but on the other hand leakage protection for electrolytes possibly emerging from a battery cell is achieved. According to the invention, this synergistic effect is achieved by providing a separate battery tray for each row of cells, which is designed to be resistant to electrolyte and to be sealed. Several of such each equipped with battery cells troughs are arranged adjacent to each other, leaving a gap space, whereby the ventilation system is created. For the position-safe arrangement of these battery trays a common battery box is provided which receives the individual battery trays. It is provided that the lower end edge of the battery trays is arranged in the height direction above the lower end edge of the battery box, so that forms in the manner described above below the battery trays a volume space, which allows an influx of cold air, which then in the fluidically with the volume space Connected gaps between the battery trays can flow.

The battery tray generic traction batteries is standardized with respect to its geometric dimensions. This is why, in order to ensure that the battery trough receiving the battery cells in the designated receiving spaces of battery devices to be operated, such as in particular vehicles properly fits into it. The battery box provided according to the embodiment of the invention has these previously known standard dimensions of a battery tray of a previously known traction battery. This ensures that even the traction battery according to the invention can be introduced in the designated receiving spaces of particular vehicles in the intended manner.

In order to allow despite the unchanged outer dimensions of the traction battery provided in the manner described above gaps between adjacent battery trays, it is proposed with the embodiment according to the invention that the battery cells used have less electrode plate pair per battery cell than the battery cells typically used according to the prior art. So find The prior art typically uses so-called 8 HPzS cells, which means that 8 positive electrode plates and 9 negative electrode plates are provided per battery cell. According to the invention, in contrast to the above-described prior art 7 HPzS battery cells are used, thus battery cells, which have only 7 positive and 8 negative electrode plates. Thus, in the width direction of the traction batteries per battery cell two electrode plates, .dh saved an electrode plate pair. As a result of this saving, the space is created with the outer dimensions of the traction battery remaining the same, which space is required in order to form the above-described gaps between adjacent battery trays.

The reduction of the plate pairs is accompanied by a reduction of the battery capacity. This, in turn, requires that the amount of current discharge, and thus ultimately the extraction time, be reduced. This disadvantage is deliberately accepted since, in practical application, it is not just the discharge time that counts but the overall cycle which is composed of the discharge time and the loading time. Since the slit spaces provided according to the invention permit, in particular following a load, a significantly faster cooling of the traction battery, the overall result is that the overall cycle is optimized overall and made significantly more effective for the benefit of the user. Applicant's research has shown that the reduction in the number of electrode plates causes the average discharge time to be shortened by 15 minutes, but the cooling time after loading is shortened by approximately 11 hours, which is an overall cycle in favor of the user results in a savings of more than 10 hours. That is, the construction of the invention provides in particular that significantly reduce changeover times, which also brings with it the advantage that less redundant devices are to be provided.

The temperature development in the current collection case results in particular as a function of the electrical resistance of the traction battery. It is therefore proposed with the invention to reduce the internal electrical resistance of the traction battery in that the current-carrying components, ie the cell poles are designed optimized with a view to a reduced internal resistance. This is achieved in particular by the fact that they are made much smaller in their geometric dimensions, in contrast to the prior art. This measure becomes a achieved reduced temperature development, which at least partially compensates for the reduced capacity by the reduced number of electrode plates. Overall, therefore, an optimized system of a traction battery is provided, which is suitable for high-current applications in an optimized manner.

Both the battery trays and the battery box are made of metal, which allows battery trays and battery box to be welded together. It is thus ensured a front-side tight closure of the battery trays, whereby the electrolyte tightness is given.

The use of metal as a material for both the battery trays and the battery box is advantageous for another reason. Thus, metal serves as a material as an optimized heat conductor, which is particularly advantageous for cooling purposes. Because cooling air flowing past the metal walls leads to a planar cooling of the overflowed metal surfaces, so that an optimized extraction of heat is ensured, which in turn leads to an optimized cooling of the battery cells accommodated by the battery trays.

According to a further feature of the invention it is provided that not only adjacent battery trays are arranged spaced from each other, and the adjacent to a side wall of the battery box battery trays are spaced from each associated side wall. In order for a corresponding gap space is also formed between a battery tray and the spaced side wall of the battery box. According to this design alternative, all the battery trays picked up by the battery box are therefore bathed in air with respect to two of its sides.

Further features and advantages of the invention will become apparent from the following description with reference to FIGS. Show

Fig. 1 in a schematic perspective view of an inventive

Traction battery;

FIG. 2 shows a detail view of the traction battery according to FIG. 1; FIG.

Fig. 3 in a further detail view of the traction battery according to the invention Fig. 1;

Fig. 4 in a further perspective view of the invention

Traction battery;

Fig. 5 is a diagram of the cooling behavior of an inventive

Traction battery;

Fig. 6 is a schematic view of a traction battery according to the prior art;

Fig. 7 in a plan view from above a traction battery according to the prior

Technique according to Fig. 6;

Fig. 8 is a perspective view of an embodiment of a

Battery box according to the invention;

FIG. 9 is a front perspective view of the battery box of FIG. 8; FIG.

Fig. 10 is a partially sectioned view of the in Fig. 8 and 9 shown

Battery box and

Fig. 1 1 is a perspective view of an external fan.

Figures 6 and 7 show a traction battery according to the prior art. A traction battery 1 according to the invention show FIGS. 1 to 4.

According to FIG. 6, a traction battery 1 according to the prior art has a battery tray 7. The latter is designed in the manner of a box and has four side walls 8 and 12 as well as a closed bottom, which is not shown in detail in FIG. For handling the traction battery 1, for example by means of a lifting device, the side walls 8 each have at their upper peripheral edge recesses 9, in which, for example, hooks can be latched.

The battery tray 7 serves to receive a plurality of battery cells 2, which are sealed packed inside the battery tray 7 and grouped into rows R and columns S.

Each battery cell 2 has, in a manner known per se, positive and negative electrode plates which are not shown in the figures and which are arranged alternately within a cell housing, not shown in detail. The cell housing also accommodates an electrolyte which flows around the electrode plates in the final assembled state. On the upper side, each cell housing is closed by means of a cell cover 4 electrolyte-tight, for example, welded.

The cell covers 4 are each made of a negative pole 6 and a plus pole 5. In the final assembled state, the battery cells 2 are electrically interconnected via their poles 5 and 6, which interconnection is not shown in greater detail in the figures for better clarity.

For stiffening the battery trough 7 intermediate walls 1 1 may be provided, as this results in particular from the illustration of FIG. 7.

FIG. 7 also shows that the battery cells 2 are densely packed and abut each other. The space provided by the battery tray 7 receiving space is thus optimally utilized.

Between the side walls 8 and 12 and the adjacent to the side walls 8 and 12 provided battery cells 2, a total circumferential compensation gap 10 is provided, as can also be seen Fig. 7 most clearly. This compensation gap 10 is used to compensate for tolerances and ensures that even at maximum tolerance tolerance, the inner dimensions of the battery trough 7 are at least so large that provided for the battery tray 7 number of battery cells 2 from the battery tray 7 can actually be recorded. For a position-safe packing of the battery cells 2 2 distance plates made of plastic are inserted into the compensation gap 10 after introduction of the battery cells. The compensation gap 10 is thus closed and the battery cells 2 are based in the final assembled state with the interposition of the compensating plates on the respectively associated side walls 8 and 12 of the battery trough 7 from. For better clarity, these compensation or spacer plates are not shown in detail in the figures. A traction battery 1 according to the invention is shown in FIGS. 1 and 2, the better overview not being shown because of battery cells 2.

According to the embodiment of the invention, a plurality of battery trays 7 are used, with each battery tray 7 serving to receive a row of battery cells 2. Each of the battery trays 7 is electrolyte-resistant and electrolyte-tight.

The traction battery 1 according to the invention also has a battery box 13. This battery box 13 accommodates the individual battery trays 7, with adjacent battery trays 7 being arranged at a distance from one another while leaving a gap 17.

2, the battery box 13 has first side walls 14 and second side walls 15. The side walls 15 of the battery box 13 extend in the longitudinal direction of the battery troughs 7.

The adjacent to the side walls 15 of the battery box 13 battery trays 7 are arranged leaving a gap 17 adjacent to the side walls 15. This results in that each battery tray 7 is air-rinsed with respect to its two large side walls 12.

To stiffen the overall construction it is provided that the gap spaces 17 accommodate a spacer 18 both between two adjacent battery trays 7 and between a battery tray and a side wall 15 of the battery box 13 adjacent thereto. Both the battery trays 7 and the battery box 13 are formed of metal and welded together. The spacers 18 are preferably made of metal and are welded to the battery trays 7 and the associated side walls 15 of the battery box 13.

As can be seen in particular from the illustration according to FIG. 3, a battery tray 7 is designed as a closed U-profile. In this case, a closure of the end faces by the side wall 14 of the battery box 13 associated with each end side takes place. In this way, a particularly simple construction is provided, since there is no need for additional components for the frontal closure of the U-profiles. In particular, Fig. 4 it can be seen that the lower end edge 19 of the battery box 13 is arranged in the height direction 3 below the lower end edges 20 of the battery trays 7. As a result, a volume space is created below the battery trays 7, which is accessible via the front side of the battery trays 7 provided gap 21. The volume space in turn is fluidically connected to the gap spaces 17, so that in the intended use, an air circulation through the column 21 into the volume space and from there through the gaps 17 in the height direction 3 is allowed upwards. As a result, an effective cooling of the battery troughs 7 limiting side walls 12 is achieved, resulting in an effective temperature dissipation and thus cooling of the recorded battery cells 7 battery cells 2.

FIG. 5 shows, by way of a diagram, the cooling behavior of a traction battery 1 according to the prior art according to the solid line. A traction battery with convective flow is shown as a dashed line. The cooling behavior of a forced flow charged transaction battery is shown in the dashed line.

In the diagram, the temperature is plotted over time in hours for cooling.

As can be seen from the diagram, a traction battery 1, which is due to a previous charging process on e.g. 52 ° C is heated, a certain cooling time to cool to an application temperature of about 30 ° C. A traction battery of the prior art requires a cooling time of about 24 hours, whereas a traction battery with convection flow has already cooled after about 14 hours, resulting in a time saving of about 10 hours. However, a forced flow traction battery has a cooling time of only about 5 hours, resulting in a time saving of approximately 20 hours. This shows the particularly advantageous effect of the invention.

The diagram according to FIG. 5 also shows that in the exemplary embodiment shown charging the traction battery 1 takes approximately 12 hours. At time t = 0, the loading is completed. As can be seen clearly from the individual graphs of the diagram, the cooling of the traction battery 1, already at the start of charging, causes a correspondingly reduced temperature at the time of the end the charge is reached. Without cooling results for the traction battery 1, a temperature of about 52 ° C, whereas with cooling according to the invention, the temperature at the end of the charge is only 41 ° C.

After the end of the charge, the cooling is continued in the manner described above. Not least because of the reduced temperature at the end of the charge results in the already described manner, a reduction of about 20 hours with respect to the inventively cooled traction battery 1 compared to the standard traction battery. The cooling according to the invention thus causes two effects. On the one hand, the battery cools down faster after charging. On the other hand, however, the temperature at the end of the charge is much lower, even if it is cooled in accordance with the invention during the charge. Thus, the temperature difference reached in the illustrated embodiment to the end of the charge is 1 1 ° C between the inventively cooled traction battery and the standard battery.

The battery box 13 according to the embodiment of the invention preferably has standardized standard dimensions in the height, width and longitudinal directions. This ensures that the traction battery according to the invention in the standard corresponding receiving spaces of e.g. Electric vehicles, charging management systems and the like. Can be accommodated.

On the one hand to provide a battery box 13 with the standard dimensions, on the other hand provides enough space to form both the gap 17 between the battery trays 7 and the volume space below the battery trays 7, the following measures are taken with the inventive design. The battery cells 2 used with respect to a certain standard standard size of the battery box 13 are made smaller in the width direction in which battery cells 2 having one electrode plate pair less than the maximum one are used. In this way, sufficient space is created in the width direction of the battery box 13 to form the above-described gap spaces 17 between adjacent battery trays 7 on the one hand or battery trays 7 and adjacent side walls 15 of the battery box 13. With this constructive measure, the disadvantage of a reduced total battery capacity is deliberately accepted in comparison to a maximum possible battery capacity for a given trough size according to the prior art. This conscious in Purchase taken disadvantage, however, more than outweighed by the possible due to the inventive design possible cooling faster reuse. In particular, the regeneration time after a loading process is much shorter due to the cooling associated with the embodiment according to the invention than with traction batteries according to the prior art, as has already been described above with reference to FIG. 5.

To comply with the standard size of the battery box 13 in the height direction 3, the battery cells 2 are executed shortened in height direction compared to the prior art. This is achieved by making the additional volume available for the electrolyte liquid above the electrode plates smaller, resulting in a reduction in the height of the battery cells as a result. Although the reduction of the additional volume for electrolyte liquid brings with it the disadvantage that shorten the maintenance intervals, but this disadvantage is also deliberately accepted, especially since the prior art electrolyte replenishing devices are known to work in automatic mode, so that maintenance work using such Systems are eliminated anyway. The reduction in the height of the battery cells 2 brings at least the advantage that the battery box 13 can be formed so that below the battery trays 7 creates a volume space. This volume space serves to distribute fresh air supplied from outside to the individual gap spaces 17 between the battery trays 7 or between the battery trays 7 and adjacent side walls 15 of the battery box 13.

The Fign. 8 to 10 show an embodiment according to the invention, in which the battery box 13 is provided in the region of the base part 16 with a bottom-side gap space 22. For this purpose, it is again covered from below, so that the gap 22, in particular in Fig. 9 to see well, is forming.

The gap space 22 is, as FIG. 10 shows, fluidically connected to the gap spaces 17 between the battery cells. That is, the gap space 22 is opposite the gap space 17 in the area 24 open. As can be seen in the exemplary embodiment shown, the gap space 22 is provided at the end 25 with a narrower flow cross-section than at the inlet end 26. Thus, it is ensured that all of the gap spaces 17 are largely uniformly charged with cooling medium become. At the junction of the gap space 22, which is closed at the other end 25, for example, as shown in Fig. 1 1 shown fan 27 can be recognized, so that over the outlet slot 28 of the gap space 22 is positively energized.

The exemplary embodiment described is only illustrative and not restrictive.

reference numeral

1 traction battery

2 battery cell

3 height direction

4 cell lid

5 plus pole

6 minus pole

7 battery tray

8 side wall

9 recess

10 compensation gap

1 1 intermediate wall

12 side wall

13 battery box

14 sidewall

15 side wall

16 bottom part

17 gap space

18 spacers

19 end edge

20 end edge

21 gap

22 gap space

23 base plate

24 flow connection

25 split ends

26 gap beginning

27 fan

28 exit slot

R series

S column

Claims

claims

1 . Traction battery, with a plurality of interconnected battery cells (2) each having in a cell housing alternately arranged positive and negative electrode plates, and with a plurality of battery trays (7), each of a plurality of battery cells (2) in series, wherein each battery tray (7) is formed electrolyte-proof and -sdicht, and with the battery trays (7) receiving battery box (13), wherein adjacent battery trays (7) leaving a gap space (17) spaced from each other, and wherein below the battery trays (7) a volume space is provided, which is in fluid communication with the gap spaces (17) and serves as a distributor gap space (22) for all the gap spaces (17), as well as with a forced flow system for a cooling medium having a means for generating a forced flow, which with the Verteilerspaltraum (22) is connectable, for which purpose the Verteilerspaltrau m (22) at its inlet end (26) has a connection for a coolant medium supply line.

2. Traction battery according to claim 1, characterized in that the forced flow system comprises at least one fan.

3. traction battery according to claim 1, characterized in that the forced flow system comprises at least one pump.

4. Traction battery according to claim 1, characterized in that the distributor gap space (22) has different flow cross sections in the flow direction.

5. traction battery according to one of the preceding claims, characterized in that in the battery box (13) fans are arranged.

6. Traction battery according to claim 1, characterized in that the connection is slot-shaped.

7. traction battery according to one of the preceding claims, characterized in that the cooling medium is air.

8. Traction battery according to one of the preceding claims, characterized in that the Verteilspaltraum (22) of a spaced apart from the battery trays (7) arranged bottom plate (23) is limited.

9. traction battery according to claim 8, characterized in that between the battery trays (7) and the bottom plate (23) spacers are arranged.

10. Traction battery according to one of the preceding claims, characterized in that the spacers are transverse to the longitudinal direction of the battery trays (7) extending webs.

1 1. Traction battery according to one of the preceding claims, characterized in that the distributor gap space (22) has a flow cross section that tapers continuously from the inlet end (26) to the opposite end (25).

12. traction battery according to one of the preceding claims, characterized in that the means for generating a forced flow comprises a fan (27).

13. traction battery according to claim 12, characterized in that the fan (27) has a housing.

14. traction battery according to claim 13, characterized in that the housing has an outlet slot (28) which is formed corresponding to the connection of the inlet-side end (26) of the Verteilerspaltraums (22).

15. Traction battery according to one of the preceding claims 12 to 14, characterized in that the fan (27) has a radial impeller.