ELECTROCHEMICAL ENERGY STORAGE

Description

[0001] The invention is based on an electrochemical energy storage device with at least one electrochemical cell.

[0002] Electrochemical energy storage devices are generally also referred to as batteries or accumulators. Rechargeable batteries, or accumulators in particular, are used to store and use electrical energy. Storing large amounts of electrical energy requires correspondingly powerful rechargeable batteries. For this purpose, it is possible, for example, to use batteries based on molten sodium and sulfur. To achieve the required capacity, the electrochemical energy storage devices typically employ several electrochemical cells that are electrically connected to one another. Such electrochemical cells, which operate on the basis of a molten alkali metal as the anode and a cathodic reactant, generally sulfur, are described, for example, in WO-A 2017 / 102697.In this process, the molten alkali metal and the cathodic reactant are separated by a cation-permeable solid electrolyte. At the cathode, the alkali metal reacts with the cathodic reactant. For example, when sodium is used as the alkali metal and sulfur as the cathodic reactant, this reaction occurs between sodium and sulfur to form sodium polysulfide. To charge the electrochemical energy storage device, the sodium polysulfide is separated back into sodium and sulfur at the electrode by applying electrical energy.

[0003] Typically, the individual electrochemical cells are stacked in so-called battery packs or, alternatively, placed parallel to each other in a housing. However, this arrangement has the disadvantage that uniform temperature control of the individual cells is difficult. In particular, flowing a temperature control medium leads to an increase in temperature as the flow path of the temperature control medium increases, resulting in a deterioration of the cooling of the electrochemical cells. This, however, is detrimental to the operation of the electrochemical energy storage system. In particular, there is a risk that excessive temperature increases could cause damage to the individual electrochemical cells.If these lead to damage to the solid electrolyte, this can result in an uncontrolled reaction that can lead to a fire in the electrochemical energy storage device, which is difficult to control.

[0004] Corresponding energy storage devices with sodium-sulfur batteries are described, for example, in JP-A 2000-297989 or US-B 7,955,725. A cooled battery module is disclosed in DE 32 47 969 A1. GB 197 183 A discloses a battery comprising battery cells attached to a carrier in a cooled housing.

[0005] The object of the present invention is to provide an electrochemical energy storage device with electrochemical cells in which uniform temperature control is possible.

[0006] This object is achieved by an electrochemical energy storage device comprising at least one electrochemical cell and a support structure, wherein the at least one electrochemical cell is suspended in the support structure and the support structure with the at least one electrochemical cell suspended therein is enclosed by a housing, wherein the housing has an inlet and an outlet (39) for a temperature control medium, which are arranged such that the temperature control medium flows from top to bottom along the electrochemical cells and the inlet for the temperature control medium is arranged above the holding device, wherein the support structure comprises at least one frame with a holding device in which the electrochemical cells are suspended and the holding device is a plate in which recesses are formed into which the electrochemical cells are suspended, wherein the recesses are further designed such thatthat a temperature control medium flows evenly through the recesses into the area in which the electrochemical cells are suspended.

[0007] Unlike horizontal or vertical electrochemical cells, it is possible to have a temperature control medium flow evenly around the hanging electrochemical cells, ensuring that they are evenly temperature-controlled. In particular, a flow of the temperature control medium parallel to the cells can be easily achieved by having the temperature control medium flow from top to bottom. A further advantage is that in the event of a single electrochemical cell being damaged, the reactants and reaction product flow downwards to the floor below the cells. This can offer an additional safety aspect, especially with highly reactive components, as the heat generated by the reaction is not directly transferred to the neighboring cells. In addition, any material that leaks from an electrochemical cell in such a case of damage can be easily removed.Another major advantage is that the supporting structure used, especially the supporting parts of the supporting structure, does not come into contact with the reactants used in the electrochemical cells in the event of damage to individual cells and the reactants leaking out. This increases the safety of the structure, as it is not damaged as a whole in the event of damage to individual electrochemical cells. Furthermore, it is also possible to use simpler construction materials, particularly black steel, for the supporting structure instead of stainless steel, which is resistant to corrosion caused by the reactants used.

[0008] To enable simultaneous flow of a temperature control medium around the electrochemical cells, the support structure with the electrochemical cells suspended within it is enclosed in a housing. The housing wall can be made of any material. Depending on the size and number of the electrochemical cells, it is possible, for example, to manufacture the housing from a metal, particularly steel, or alternatively, in the case of a large electrochemical energy storage system, to use a masonry building as the housing. To make a large electrochemical energy storage system transportable, it is also possible to use a housing similar to a standard container, for example a 20-foot or 40-foot container. These can then be moved using the usual means of transport used for such standard containers.A further advantage of using such standard containers is that several such containers can be combined to form a large energy storage unit, providing greater storage capacity or higher available power from the electrochemical energy storage system. Due to the high temperatures at which alkali metal sulfur cells, especially sodium sulfur cells, operate, it is also advantageous to thermally insulate the housing. The thermal insulation can be applied to both the inside and outside of the housing. It is also possible to provide a double wall for the housing and install the insulation between the walls.

[0009] To enable easy assembly of the electrochemical energy storage device, the support structure comprises at least one frame with a holding device in which the electrochemical cells are suspended. The use of a frame with an additional holding device in which the electrochemical cells are suspended makes it possible to carry out pre-assembly outside the housing. In this case, the electrochemical cells are first inserted into the holding device and this is connected to the frame. Alternatively, it is also possible to first insert the holding device into the frame and then equip the holding device with the electrochemical cells. In a next step, the frame with the holding device containing the electrochemical cells is inserted into a base frame, which is also part of the support structure.

[0010] For easy assembly, the base frame preferably has rails onto which at least one frame is slid. The use of rails further simplifies the assembly of the electrochemical energy storage device.

[0011] Conventional U-profiles or L-profiles, for example, can be used as rails on the base frame of the supporting structure. It's important to ensure that the rails run parallel to each other to prevent the frames from jamming or falling through the rails when sliding them onto the rails due to possible gaps.

[0012] The number of electrochemical cells provided per frame depends on the size of the electrochemical cells used. Particularly preferred electrochemical cells used in the electrochemical energy storage device are sodium-sulfur cells. Such sodium-sulfur cells are typically cylindrical and have a diameter in the range of 6 to 20 cm and a length in the range of 50 to 200 cm. Corresponding sodium-sulfur cells are known to those skilled in the art and are described, for example, in WO-A 2017 / 102697.

[0013] The holding device from which the electrochemical cells are suspended is a plate with recesses into which the electrochemical cells are suspended. The use of a plate as a holding device with recesses into which the electrochemical cells are suspended allows for a uniform flow of the temperature control medium through the housing in which the support structure is housed. For this purpose, the temperature control medium is supplied above the plates, with the space in the housing above the plates acting as a distributor. The temperature control medium then flows evenly through the recesses in the plates into the area in which the electrochemical cells are suspended. The temperature control medium thus flows evenly across the entire cross-sectional area of ​​the electrochemical energy storage device, parallel to the suspended electrochemical cells, from top to bottom.To achieve a uniform flow across the entire length of the cells from top to bottom, it is also possible to provide another plate with openings below the cells, beneath which the temperature control medium collects and is then drawn out of the housing. With sufficiently dense packing of the electrochemical cells, where the electrochemical cells almost touch each other, it is also possible to use the space below the cells as a collector, since the temperature control medium will essentially flow between the cells from top to bottom through the channels formed by the cylindrical shape of the cells.

[0014] In order to securely suspend the electrochemical cells in the holding device and, in particular, to prevent them from moving when the holding device moves, for example when pushed into the base frame or when the housing moves, which could result in the electrochemical cells falling out of the holder, the holding devices must be designed to prevent the cells from falling out. This can be achieved, for example, in that each holding device preferably has an opening and a slot adjoining the opening, as well as a tab that encloses an angle to the surface of the plate in the range of at least 45°, preferably in the range of 90 to 180°, wherein the tab is arranged on the side of the opening facing the slot.In this case, a support on the electrochemical cell is guided through the opening over the tab for assembly and, when mounted, projects downwards behind the tab through the slot. The tab then prevents the electrochemical cell's suspension from slipping. For installation in a suitable holding device, the electrochemical cell's suspension has a tab bent by at least 90° at the corner facing away from the electrochemical cell. The suspension is then guided through the slot, and the tab rests on the plate used as the holding device. For this purpose, the tab is particularly preferably bent by 90°.

[0015] In order to create recesses in the plate with an opening and a slot adjoining the opening as well as a tab that forms an angle to the surface of the plate, it is preferable to make a U-shaped slot in the plate at the respective positions where the electrochemical cells are to be suspended, with one leg of the U-shaped slot being twice as long as the other. The tab thus created between the two legs of the U-shaped slot is then bent upwards at a bending edge that runs parallel to the base of the U-shaped slot. Alternatively, it is of course also possible to cut out the entire opening and then weld on a tab. However, it is preferable to create a U-shaped slot and bend the tab upwards.

[0016] To enable pre-assembly outside the housing, it is necessary to design the frames and the holding device in a size that is still manageable. The individual electrochemical cells are preferably suspended in parallel rows in the holding device. When sodium-sulfur cells are used as electrochemical cells, each frame is preferably equipped with 6 to 60 cells. These are preferably suspended in 1 to 5 rows, in particular in 1 to 2 rows, with 5 to 20 electrochemical cells and in particular 8 to 12 electrochemical cells being suspended in each row. The advantage of only 1 or 2 rows per frame is that every cell is directly accessible after a frame has been removed. The number of electrochemical cells per row still allows for good handling of the individual frames. The number of cells per row in the range of 5 to 20 and preferably 8 to 12 further prevents the holding device from sagging.

[0017] If a plate with openings is used as the holding device, the thickness of the plate is selected to ensure stable support for the number of electrodes suspended in the plate, i.e., the cells can be held without sagging. When using sodium-sulfur cells and 1 to 5 rows per cell, each with 5 to 20 electrochemical cells, the thickness of the plate used as the holding device is preferably in the range of 2 to 10 mm.

[0018] As an alternative to plates with openings as a holding device, it is also possible to use supports from which the individual electrochemical cells are suspended. Suitable supports for this purpose include double U-beams, T-beams, L-beams, or hollow profiles with any cross-sectional shape. To prevent the electrochemical cells from slipping on or off the supports, the suspensions for the electrochemical cells each have a hook that is preferably adapted to the geometry of the support. It is also advantageous to provide the supports with stoppers, which are arranged on either side of the suspension for the electrochemical cell, so that the stoppers prevent the electrochemical cells from slipping sideways. The stoppers can be connected to the support either positively, for example by welding, soldering, or gluing, or force-fitting, for example by screwing.

[0019] However, it is preferred to use a plate with openings as the holding device.

[0020] To prevent the individual electrochemical cells from hitting each other during assembly or transport of the electrochemical energy storage device, the electrochemical cells preferably each have a spacer at their lower end. Rings can be used as spacers, for example, which enclose the electrochemical cells at their lower end. The rings are preferably made of a temperature-resistant, electrically non-conductive material, such as a mineral fiber material. Alternatively, it is also possible to provide a plate with recesses through which the electrochemical cells are guided as a spacer. With such a plate, the individual electrochemical cells would be fixed in their position and could not move any further.However, to enable easy replacement of individual electrochemical cells, it is preferred that each cell be provided with a separate spacer.

[0021] As an alternative to a ring made of a temperature-resistant, electrically non-conductive material surrounding the electrochemical cell, it would also be possible to provide tabs as spacers that are attached directly to the electrochemical cell and to preferably cover each tab with an insulating material to prevent the spacers from damaging neighboring cells.

[0022] To control the temperature of the electrochemical cells—that is, to heat or cool them as needed—the housing features an inlet and an outlet for the temperature control medium. The inlet for the temperature control medium is located above the electrochemical cells, and the outlet is located below them. The plates used to suspend the electrochemical cells act as distributors for the temperature control medium, ensuring that all electrochemical cells within the housing are evenly flowed with the temperature control medium. The inlet for the temperature control medium is located above the plates.To prevent the temperature control medium from flowing directly to the temperature control medium drain after flowing through the plates serving as distributors, but instead to flow downwards through the housing parallel to the electrochemical cells, it is possible, for example, to insert a plate with recesses below the electrochemical cells and to place the drain below this plate. Alternatively, it is also possible to design the spacers of the electrochemical cells in such a way that they leave individual openings between the electrochemical cells, forming a collector below the spacers through which the temperature control medium can then be removed.

[0023] To achieve a uniform distribution of the gas flow across the electrochemical cells, the openings are preferably selected to be sufficiently small to generate a pressure drop that is significantly higher than the pressure differences in the distribution chamber above the plate with openings. Alternatively, for a uniform gas flow, it is also possible to provide different opening sizes along the module length. However, it is preferred to select the openings so small that a pressure drop is generated that is significantly higher than the pressure differences in the distribution chamber.

[0024] If it is not possible to generate a uniform gas flow through the holding device for the electrochemical cells, for example if supports are used instead of a plate with openings or if the openings have to be so large that the pressure loss across the openings is too small to generate a uniform flow, it is also possible to additionally provide a gas distributor above the holding device for the electrochemical cells. For this purpose, a plate with openings or a plate with valves can be used. A plate with openings through which a uniform gas flow over the electrochemical cells is generated is preferred. If an additional gas distributor is used, it is alternatively possible to provide it below the electrochemical cells and direct the gas flow from bottom to top.However, a gas distributor above the electrochemical cells and a gas flow from top to bottom are preferred.

[0025] When sodium-sulfur cells are used as electrochemical cells, heating is required for initial operation. This requires raising the temperature of the individual electrochemical cells to a temperature above the melting points of the reactants. Once the reactants have melted and the electrochemical cell can be put into operation, heat is released in the cells during charging or discharging, so cooling of the electrochemical cells is usually necessary.

[0026] A gas is preferably used as the temperature control medium for the electrochemical cells. Particularly preferred are gases that are inert toward the reactants used, i.e., alkali metals, especially sodium, sulfur, and the resulting alkali metal polysulfide. Suitable gases include, in particular, nitrogen, carbon dioxide, or noble gases.

[0027] In order to heat the gas to the temperature required to start up the electrochemical energy storage device or to dissipate the heat released within the electrochemical cells during operation, a channel is included to which the inlet and outlet for the temperature control medium are connected outside the housing. A heat exchanger and a conveying device for the temperature control medium are accommodated in the channel. If gases are used as the temperature control medium, a blower is used as the conveying device. This fan must be designed to withstand the temperatures during operation of the electrochemical energy storage device. Any heat exchanger known to those skilled in the art with which gases can be heated or, alternatively, cooled can be used as the heat exchanger. Suitable heat exchangers include, for example, plate heat exchangers or tube bundle heat exchangers.To increase the heat transfer surface, the individual tubes or plates of the heat exchanger can be equipped with additional fins. In addition to a heat exchanger, any other heating device, such as an electric heater, can be used to heat the gas.

[0028] Any heat transfer medium that is stable at the corresponding temperatures can be used as the heat transfer medium used to cool or heat the cells. Synthetic heat transfer oils or gases are particularly suitable.

[0029] Embodiments of the invention are illustrated in the figures and are explained in more detail in the following description.

[0030] They show: Figure 1 shows an electrochemical energy storage device comprising a plurality of electrochemical cells, Figure 2 shows a section of a support structure for the electrochemical cells, Figure 3 shows an opening in a holding device for receiving an electrochemical cell, Figure 4 shows the Figure 3 shown opening with a tab accommodated therein for fastening the electrochemical cells, Figure 5 an electrochemical energy storage device with a schematically illustrated temperature control circuit.

[0031] Figure 1 shows an electrochemical energy storage device with a large number of electrochemical cells in a three-dimensional representation.

[0032] An electrochemical energy storage device 1 comprises a support structure 3 with electrochemical cells 5 suspended in the support structure 3.

[0033] The support structure 3 comprises a base frame 7 with supports 9. The supports 9 are connected to crossbeams 11. In addition, the support structure 3 of the embodiment shown here comprises a base plate 13. However, as an alternative to the base plate 13, it is also possible to provide, for example, cross braces.

[0034] For better clarity, Figure 1 The front right support is shown cut away. For a statically stable base frame 7, all supports 9 at the corners of the base frame 7 are preferably designed identically. The individual supports 9 can, for example, be designed as square tubes, as shown here. Alternatively, it is also possible to manufacture the supports 9 as solid tubes or to design them in the form of L-, T-, or double-T profiles. It is also possible to use hollow profiles with any other cross-section, for example, a round cross-section. However, it is preferred to design the supports 9 as square hollow profiles.

[0035] The crossbeams 11, like the supports 9, can have any shape, for example, hollow profiles with any cross-section, such as round or square profiles, although square hollow profiles are preferred here as well. In addition to the hollow profiles mentioned, it is also possible to use L-, T-, U-, or double-T-profiles for the crossbeams 11.

[0036] To accommodate the electrochemical cells, additional rails 15 are provided on the base frame 7. Holding devices 17 for the electrochemical cells 5 are pushed onto the rails 15. The rails 15 are preferably L-profiles or U-profiles.

[0037] In the embodiment shown here, the rails are mounted along the long sides of the base frame 7. This has the advantage that the holding device 17 can be kept shorter than if it were inserted transversely across the long side of the base frame 7, so that sagging of the holding device 17 is reduced or advantageously prevented.

[0038] If it is necessary to insert the holding device 17 over the long side of the base frame 7, it is preferable to divide the long side with additional supports 9 so that several holding devices 17 are inserted side by side into the base frame 7. Depending on the length of the base frame 7, it is thus possible, for example, to insert two, three, or more holding devices 17 side by side into the base frame.

[0039] A section of a support structure for the electrochemical cells is shown in Figure 2 shown.

[0040] In addition to the holding device 17, the support structure preferably also comprises a frame 19 on which the holding device 17 rests. The holding device 17 is, as shown here, a plate with recesses 21.

[0041] In order to enable easy insertion of the holding device 17, which is designed as a plate, into the frame 19, the frame is preferably constructed from L-profiles, as shown here.

[0042] In the embodiment shown here, the electrochemical cells 5 each have two suspensions 23. The suspensions 23 are guided through the recesses 21 and rest with a tab 25 on the holding device 17, which is designed as a plate. The use of two suspensions 23 achieves a more stable suspension of the individual electrochemical cells 5, so that they are less likely to vibrate than if only one suspension 23 were provided. Of course, it is also possible to provide only one suspension 23 or more than two suspensions 23.

[0043] To assemble the electrochemical energy storage device 1, the frame 19 equipped with the holding device 17 designed as a plate and the electrochemical cells 5 is then pushed onto the rails 15 of the basic frame 7.

[0044] A possible design for a recess 21 in which a suspension 23 is accommodated is shown in Figure 3presented in detail.

[0045] The recess 21 formed in the holding device 17, which is designed as a plate, has an opening 27 and a slot 29 adjoining the opening 27. Additionally, a tab 31 is arranged at the end of the opening 27 facing the slot 29. The tab 31 preferably forms an angle to the surface of the holding device 17, which is designed as a plate, in the range of 45 to 180°, and particularly preferably 90°. When an electrochemical cell is suspended, the tab 31 acts as a stop, preventing the electrochemical cell from slipping out of the holding device.

[0046] Figure 4 shows the Figure 3The recess 21 shown has a suspension 23 received therein. The suspension 23 has a tab 25, which is bent substantially by 90° and rests on the holding device 17 designed as a plate. Because the tab 25 of the suspension 23 rests against the upwardly bent tab 31, the suspension 23 is prevented from slipping toward the opening 27 and falling out through the opening 27. The suspension 23 is guided through the slot 29.

[0047] In addition to the design shown here, in which the suspension 23 is designed as a strip with a rectangular cross-section, any other cross-sectional shape for the suspension 23 is also possible. For example, it can be designed as a wire with a round cross-section or from several wires arranged side by side, which are also connected to additional transverse wires. Any other design for the suspension 23 is also possible. However, due to its ease of manufacture, a strip design, as shown here, is preferred.

[0048] To produce the recess 21, it is possible to cut it out completely and then attach the tab 31 to the end of the opening 27 pointing towards the slot 29. In this case, the tab 31 can be welded, soldered, glued, screwed or riveted on, for example. However, it is preferred to create a U-shaped slot in the holding device 17 designed as a plate, with one leg of the U-shaped slot being at least twice as long as the other leg. The tab 31 is then bent upwards at a bending edge running parallel to the base of the U-shaped slot at the end of the shorter leg. This avoids having to attach a separate tab 31 to each recess 21.

[0049] However, if the individual recesses 27 are punched out of the holding device 17 designed as a plate, it is also possible to provide any other stopper instead of the tab 31 shown here, which prevents the suspension 23 from slipping out of the slot 29 into the opening 27 and thus from slipping off the holding device. If such a stopper other than a tab 31 is attached, it can be connected to the holding device 17 designed as a plate, for example, by welding, gluing, soldering, screwing, or riveting, as already described above.

[0050] Since heat is typically released during charging and discharging, regardless of the type of electrochemical cell, temperature control is required to prevent overheating of the individual electrochemical cells. In addition, when using alkali metal sulfur cells, the electrochemical energy storage device must be brought to operating temperature before commissioning—that is, a temperature above the melting points of sodium and sulfur. This requires temperature control of the electrochemical energy storage device.

[0051] Such temperature control is usually carried out via a temperature control circuit, as shown schematically in Figure 5 is shown.

[0052] In order to be able to control the temperature of the electrochemical cells of the electrochemical energy storage device, the electrochemical energy storage device has a housing 35. The housing 35 encloses the basic structure 7 with the electrochemical cells 5 suspended therein. To increase the energy efficiency of the energy storage device, it is preferred if the housing 35 is thermally insulated. The thermal insulation can be applied to the inside of the individual housing walls or to the outside. Alternatively, it is also possible to manufacture the housing 35 from a thermally insulating material. The housing 35 can, for example, be made from sheet metal, in particular steel sheets, which are thermally insulated on the inside or outside. Any insulating material known to those skilled in the art can be used for the thermal insulation.Alternatively, it is also possible to construct the housing from a mineral material, such as masonry. The advantage of the housing 35 made of sheet steel, however, is that in this case, a portable electrical energy storage device can be provided, whereas an electrochemical energy storage device at a fixed location can also be enclosed with a masonry housing 35.

[0053] The housing 35 has an inlet 37 and an outlet 39 for a temperature control medium. In order to achieve uniform temperature control of the individual electrochemical cells, the temperature control medium flows around them from top to bottom. In order to achieve uniform flow of the temperature control medium around all electrochemical cells, the inlet 37 is located above the holding device 17. The holding device also acts as a distributor for the temperature control medium. The space above the holding devices serves as a distributor, and the temperature control medium flows through the recesses 21 to the electrochemical cells 5. The outlet 39 is then located below the electrochemical cells 5. To prevent cross-flow, it is further advantageous if a perforated plate is provided below the electrochemical cells 5, below which the temperature control medium is collected.Alternatively, a sufficiently dense arrangement of electrochemical cells 5 is also possible, so that neighboring electrochemical cells 5 almost touch each other, forming channels between the electrochemical cells through which the temperature control medium flows from top to bottom. "Almost touching" is to be understood as ensuring that the distance is as small as possible, but remains large enough so that the neighboring electrochemical cells 5 definitely do not touch each other, in order to avoid a short circuit. The temperature control medium then collects below the electrochemical cells and can be removed via drain 39.

[0054] In order to prevent the individual electrochemical cells from colliding with each other, particularly during assembly of the electrochemical energy storage device 1 or during transport of the electrochemical energy storage device 1, or to prevent the electrochemical cells from touching each other during operation, the electrochemical cells are preferably provided with a spacer at their lower end. A ring 41, as shown schematically in Figure 1is shown. The ring 41 is preferably made of a temperature-resistant, non-conductive material, which must be stable against the temperatures occurring in the housing 35. As an alternative to a ring 41, however, it is also possible to provide spacers directly on the individual electrochemical cells, which are covered with an elastic material in order to prevent damage in the event of contact with neighboring cells. Furthermore, it is also possible to provide a plate with openings through which the electrochemical cells are guided. In this case, additional openings must be provided through which the temperature control medium can flow in order to enable temperature control of the electrochemical cells.

[0055] The tempering medium removed from the housing 35 via the outlet 39 is then passed through a heat exchanger 43, a heating device 45, and a conveying device 47 and subsequently fed back into the housing 35 via the inlet 37. The heat exchanger 43, the heating device 45, and the conveying device 47 are preferably arranged in a channel, which can be designed as a pipeline or as a channel with any other cross-section, for example, as a rectangular channel.

[0056] The heat exchanger 43 serves, in particular, to cool the temperature control medium when the temperature control medium is used to cool the electrochemical cells, as is necessary, for example, in alkali metal sulfur cells during the charging and discharging process. In this case, the temperature control medium in the heat exchanger 43 transfers heat to another temperature control medium, which can be water or any other conventional temperature control medium, such as thermal oil.

[0057] A heating device is provided if heat must be supplied either for the operation of the electrochemical cell or for starting up the electrochemical cell. The temperature control medium is heated in the heating device. The heating can be carried out directly or indirectly, with indirect heating being achieved, for example, by using a temperature control medium that transfers heat to the temperature control medium to control the temperature of the electrochemical cells. However, only temperature control media that are stable at temperatures above the temperature to which the temperature control medium is to be heated can be used. Suitable heating media would be, for example, molten salts. It is therefore preferable to use a heating device in which the temperature control medium is heated electrically or inductively, or by combustion of a fuel.

[0058] As an alternative to the embodiment shown here with a heat exchanger 43 for cooling and a separate heating device 45, it is also possible to use a single heat exchanger that serves both heating and cooling. For this purpose, the temperature of the temperature control medium can be varied for both heating and cooling, or a combination device can be used that uses a temperature control medium for cooling and additionally contains electrical heating elements for heating, which can be used to heat the temperature control medium as needed to control the temperature of the electrochemical cells.

[0059] The conveying device 47 depends on the temperature control medium used. Typically, a gas is used as the temperature control medium for the electrochemical cells 5, so the conveying device 47 is a blower.

[0060] To prevent a chemical reaction from occurring if an electrochemical cell is damaged, a gas inert to the reactants used in the electrochemical cells is used as the temperature control medium. Preferred temperature control media are nitrogen, carbon dioxide, or noble gases such as argon. Nitrogen is particularly preferred.

[0061] The conveying device 47 is dimensioned such that a sufficient quantity of tempering medium for tempering the electrochemical cells can be passed through the housing 35. List of reference symbols

[0062] 1Electrochemical energy storage device 3Supporting structure 5Electrochemical cell 7Basic frame 9Supports 11Cross beam 13Base plate 15Rail 17Holding device 19Frame 21Recess 23Suspension 25Tab 27Opening 29Slot 31Tab 35Housing 37Inlet 39Outlet 41Ring 43Heat exchanger 45Heating device 47Conveying device

Claims

1. An electrochemical energy store comprising at least one electrochemical cell (5) and a support structure (3), wherein the at least one electrochemical cell (5) is accommodated in a suspended manner in the support structure (3) and the support structure (3) together with the at least one electrochemical cell (5) accommodated therein in a suspended manner is enclosed by a housing (35), wherein the housing (35) has an inlet (37) and an outlet (39) for a temperature control medium, which are arranged in such a way that the temperature control medium flows from the top downward along the electrochemical cells (5) and the inlet (37) for the temperature control medium is arranged above the holding device (17), wherein the support structure (3) comprises at least one frame (19) with a holding device (17) in which the electrochemical cells (5) are suspended and the holding device (17) is a plate in which there are cutouts (21) in which the electrochemical cells (5) are suspended, wherein the cutouts (21) are further configured such that a temperature control medium flows uniformly through the cutouts (21) into the region in which the electrochemical cells (5) are suspended.

2. The electrochemical energy store according to claim 1, wherein the cutouts (21) each comprise an opening (27) and a slot (29) adjoining the opening (27), and also a bracket (31) which includes an angle to the surface of the plate in the range from 45 to 180°, with the bracket (31) being arranged on the side of the opening (27) facing the slot (29).

3. The electrochemical energy store according to either of claims 1 and 2, wherein the electrochemical cells (5) each have a suspension (23) which at its end facing away from the electrochemical cell (5) has a bracket (25) bent through at least 90°.

4. The electrochemical energy store according to claim 2 or 3, wherein the suspension (23) of the electrochemical cell (5) has been passed through the slot (29) and rests with the bracket (25) bent through 90° on the plate.

5. The electrochemical energy store according to any of claims 1 to 4, wherein the support structure (3) comprises a main framework (7) having rails (15) onto which the at least one frame (19) has been pushed.

6. The electrochemical energy store according to any of claims 1 to 5, wherein the electrochemical cells (5) each have a spacer (41) at their lower end, in order to prevent the individual electrochemical cells (5) from knocking against one another during assembly or during transport of the electrochemical energy store (1).

7. The electrochemical energy store according to any of claims 1 to 6, wherein a channel to which the inlet (37) and the outlet (39) for the temperature control medium are connected outside the housing (35) is provided, with a heat exchanger (43) and a transport device (47) for the temperature control medium being accommodated in the channel.

8. The electrochemical energy store according to any of claims 1 to 7, wherein the electrochemical cells (5) are sodium-sulfur cells.