Clamping device and method for clamping a stack of electrochemical units

Abstract

To create a clamping device for clamping a stack of electrochemical units arranged between clamping plates, the clamping device comprising at least one clamping band system, each clamping band system comprising at least one clamping band having a first clamping band end and a second clamping band end, and at least one locking system for connecting two clamping band ends, the locking system comprising a first locking element, a second locking element, and a clamping element for clamping the locking elements, each clamping system comprising a clamping screw oriented along a shaft direction from a screw head to a shaft end, and the clamping band system or systems having a common direction of rotation directed from a first clamping band end of a first clamping band system to a second clamping band end of the same clamping band system,In order to at least reduce the uneven application of the clamping force to the clamping plates, it is proposed that the clamping device comprise several clamping band systems, wherein the clamping screws of a first clamping screw group have a first shaft direction aligned parallel to the common direction of rotation and the clamping screws of a second clamping screw group have a second shaft direction aligned antiparallel to the common direction of rotation, wherein the first clamping screw group and the second clamping screw group each comprise at least one clamping screw.

Description

[0001] The present invention relates to a clamping device for clamping a stack of electrochemical units that follow one another along a stacking direction and are arranged between clamping plates, wherein the tensioning device comprises at least one tensioning band system, wherein each tensioning band system comprises at least one tensioning band comprising a first tensioning band end and a second tensioning band end, and at least one locking system for connecting a first tensioning band end of a tensioning band to a second tensioning band end of the same tensioning band or of another tensioning band, wherein the locking system each has a first locking element which is in contact with a first tension band end, a second locking element which is in contact with a second tension band end, and a tensioning element for tensioning the first locking element and the second locking element comprises, wherein each locking system comprises a clamping element which includes a clamping screw which is aligned along a shaft direction directed from a screw head of the clamping screw to a shaft end of the clamping screw, and wherein the tension band system or tension band systems have a common direction of rotation, which is directed from a first tension band end of a first tension band system to a second tension band end of the same tension band system, which is tensioned to the first tension band end by means of a tensioning element.

[0002] Such clamping devices are known from the prior art and serve to generate sufficient tension between the electrochemical units of the stack of electrochemical units, which must lie within a defined clamping force range to achieve optimal performance of the electrochemical device formed from the electrochemical units.

[0003] The at least one tension band of each tension band system is placed over the clamping plates, which limit the stack of electrochemical units at both ends of the stack.

[0004] The clamping plates distribute the clamping force applied via the at least one clamping band over the electrochemically active areas of the electrochemical units.

[0005] One aim of the tensioning is to achieve the most homogeneous force distribution possible in the electrochemically active areas of the electrochemical units of the electrochemical device.

[0006] Since a tension band is usually not wide enough to cover the clamping plates across their entire width, several tension band systems are usually used, preferably three or more tension band systems.

[0007] A tension band system can consist of a single tension band with two tension band ends that are tensioned together by means of a locking system.

[0008] Alternatively, a tension band system can also comprise several tension bands, the ends of which are tensioned together by a number of locking systems corresponding to the number of tension bands.

[0009] The locking systems for clamping the ends of the tension bands can be arranged either on the clamping plates at the ends of the stack of electrochemical units or laterally next to the stack of electrochemical units, in the area between the clamping plates.

[0010] A commonly used locking system for such a tension band system comprises two locking elements in the form of round bolts, each locking element having a through hole and at least one of the through holes having an internal thread.

[0011] The locking elements are each enclosed by a tension band end, whereby the tension band ends can have the form of a tension band loop, a tab or a hook.

[0012] Alternatively or additionally, it may be provided that a tab or hook is applied to a tension band end via another element.

[0013] The ends of the tension bands, guided around the locking elements of a locking system, are tensioned together by screwing the locking elements together using a tensioning element.

[0014] Such a clamping element can in particular include a clamping screw which engages in an internal thread in a through hole of one of the locking elements.

[0015] Each locking element can also have a contact surface for a clamping element, in particular a clamping screw, and / or a flattened side.

[0016] In clamping devices known from the prior art, the shaft directions of all clamping screws, directed from the screw head to the shaft end of the clamping screw, are aligned parallel to each other, so that all locking systems are always screwed from the same side.

[0017] Such a one-sided screw connection of the locking systems results in an uneven introduction of the clamping force into the clamping plates due to the geometric boundary conditions and the friction between the locking elements, the tension bands and the clamping plates.

[0018] This can cause the clamping plates to tilt relative to each other, resulting in an inhomogeneous application of the clamping force to the electrochemically active areas of the electrochemical units within the stack of electrochemical units in the electrochemical device. This inhomogeneous application of the clamping force can impair the performance of the electrochemical device and accelerate the degradation of the electrochemical units within the device.

[0019] The present invention is based on the objective of creating a clamping device for clamping a stack of electrochemical units of the type mentioned at the outset, in which an uneven introduction of the clamping force into the clamping plates and in particular a tilting of the clamping plates relative to each other is prevented or at least reduced.

[0020] This problem is solved in a clamping device with the features of the preamble of claim 1 according to the invention in that the clamping device comprises several clamping band systems, wherein the tensioning screws of a first tensioning screw group have a first shaft direction aligned parallel to the common direction of rotation of all tensioning band systems and the tensioning screws of a second tensioning screw group have a second shaft direction aligned antiparallel to the common direction of rotation of all tensioning band systems, wherein the first tensioning screw group and the second tensioning screw group each comprise at least one tensioning screw.

[0021] The present invention is based on the concept of designing the clamping device in such a way that, when the clamping screws of the locking systems are tightened, the clamping force is either introduced uniformly into both ends of the clamping band connected to each other by the locking system, or any one-sided introduction of the clamping force into the ends of one clamping band system is compensated by the opposite one-sided introduction of the clamping force into the ends of one or more other clamping band systems.

[0022] The choice of the common direction of rotation of all tension band systems of the tension band device is fundamentally arbitrary and can also be replaced by a precisely antiparallel alternative direction of rotation; for the realization of the inventive idea, it is only important how the shaft directions of the tensioning screws are aligned relative to each other.

[0023] In a particular embodiment of the invention, it is provided that the first clamping screw group and the second clamping screw group comprise the same number of clamping screws. wherein, along a transverse direction of the stack of electrochemical units perpendicular to the common direction of rotation, a tension band system comprising a tension screw of the first tension screw group and a tension band system comprising a tension screw of the second tension screw group alternately follow one another and / or wherein the sequence of tension band systems comprising a tension screw of the first tension screw group and of tension band systems comprising a tension screw of the second tension screw group is formed in a mirror-symmetrical manner along the transverse direction with respect to a longitudinal median plane of the stack of electrochemical units aligned parallel to the common direction of rotation and parallel to the stacking direction.

[0024] If a tension band system comprising a tension screw of the first tension screw group is assigned type A and a tension band system comprising a tension screw of the second tension screw group is assigned type B, then the sequence of tension band systems along the transverse direction can be, for example, ABAB or BABA (alternating succession of the two types A and B of tension band systems) or ABBA or BAAB (mirror-symmetrical sequence of types A and B of tension band systems).

[0025] In another special embodiment of the clamping device, it is provided that the first clamping screw group and the second clamping screw group comprise a different number of clamping screws. wherein the sequence of tension band systems comprising a tension screw of the first tension screw group and of tension band systems comprising a tension screw of the second tension screw group is formed in a transverse direction perpendicular to the common direction of rotation and in a mirror-symmetrical manner with respect to a longitudinal median plane of the stack of electrochemical units oriented parallel to the common direction of rotation and parallel to the stacking direction.

[0026] If a tension band system comprising a tension screw of the first tension screw group is assigned to type A and a tension band system comprising a tension screw of the second tension screw group is assigned to type B, then such a sequence of tension band systems along the transverse direction can be, for example, ABA (or BAB).

[0027] It is preferably provided that the at least one clamping screw of the clamping screw group comprising a smaller number of clamping screws transmits a higher clamping force than the clamping screws of the clamping screw group comprising a larger number of clamping screws. In this way, it is possible to maintain an approximate balance between the forces introduced into the clamping plates by the clamping band systems of type A and type B, even if the number of clamping band systems of type B is smaller than the number of clamping band systems of type A, because a higher clamping force can be transmitted by means of the clamping screws of the clamping band systems of type B than by means of the clamping screws of the clamping band systems of type A.

[0028] This can be achieved, for example, by ensuring that at least one tensioning screw of a type B tensioning system has a larger diameter than the tensioning screws of the type A tensioning systems.

[0029] Alternatively or additionally, the problem underlying the present invention is also solved according to the invention in a clamping device with the features of the preamble of claim 1 by the fact that at least one clamping band system comprises at least one clamping element which includes a clamping screw which is provided with a left-hand thread section and with a right-hand thread section.

[0030] The clamping screw preferably engages with its left-hand thread section into an internal left-hand thread of one of the locking elements of the locking system associated with the clamping element, and with its right-hand thread section into an internal right-hand thread of the other locking element of the locking system associated with the clamping element.

[0031] If the left-hand thread section and the right-hand thread section of the tensioning screw have the same thread pitch, then when the tensioning screw is tightened, both ends of the tension band connected by the locking system will be subjected to the same clamping force.

[0032] It is therefore preferably provided that the left-hand thread section and the right-hand thread section of the same clamping screw have the same thread pitch in terms of magnitude.

[0033] In one variant of this embodiment of the invention, it can also be provided that the left-hand thread section and the right-hand thread section of the same clamping screw have different thread pitches, because these different thread pitches can compensate for an existing asymmetry in the introduction of the clamping force into the locking system.

[0034] Alternatively or additionally, the problem underlying the present invention is also solved in a clamping device with the features of the preamble of claim 1 in that at least one clamping band system comprises at least one clamping element which includes a clamping screw and a clamping nut arranged on the clamping screw, wherein a shaft portion of the clamping screw extends through a through hole in the first locking element and through a through hole in the second locking element, wherein the radial play of the clamping screw in the through hole closer to the clamping nut differs from the radial play of the clamping screw in the other through hole.

[0035] Preferably, it is provided that the radial play of the clamping screw in the through hole closer to the clamping nut is greater than the radial play of the clamping screw in the other through hole.

[0036] By simultaneously tightening the clamping nut and the clamping screw, or by alternately tightening the clamping nut and the clamping screw in opposite directions, it can be ensured that the two ends of the clamping band connected by the locking system are subjected to the clamping force evenly, thus preventing the clamping plates from tilting relative to each other.

[0037] The present invention further relates to a method for clamping a stack of electrochemical units that follow one another along a stacking direction and are arranged between clamping plates, by means of a clamping device, wherein the clamping device comprises at least one clamping band system, wherein each clamping band system has at least one clamping band having a first clamping band end and a second clamping band end, and comprising at least one locking system for connecting a first tension band end of a tension band to a second tension band end of the same tension band or of another tension band, wherein the locking system each has a first locking element which is in contact with a first tension band end, a second locking element which is in contact with a second tension band end, and includes a tensioning element for tensioning the first locking element and the second locking element.

[0038] The present invention is based on the further objective of creating a method for clamping a stack of electrochemical units in which an uneven introduction of the clamping force into the clamping plates and, in particular, a tilting of the clamping plates relative to each other is prevented or at least avoided.

[0039] This problem is solved in a method with the features of the preamble of claim 8 according to the invention in that each clamping element comprises a clamping screw and a clamping nut arranged on the clamping screw, wherein the clamping screw and the clamping nut are tightened simultaneously or alternately in opposite directions during the clamping of the first locking element and the second locking element.

[0040] The inventive method is based on the concept that the clamping force is introduced uniformly into both ends of the clamping band which are connected to each other by the locking system, so that an inhomogeneous introduction of the clamping force into the clamping plates of the electrochemical device and in particular a tilting of the clamping plates relative to each other is avoided.

[0041] Alternatively or additionally, the problem underlying the present invention is also solved according to the invention in a method for clamping a stack of electrochemical units with the features of the preamble of claim 8 by the fact that each clamping band system comprises two or more locking systems, where the tensioning elements of all locking systems of a tension band system are tightened simultaneously or alternately.

[0042] By tightening the clamping elements of the multiple locking systems simultaneously or in a uniformly alternating manner, it is ensured that the clamping band ends connected to each other by the locking systems, and thus also the clamping plates, are subjected to the clamping force uniformly.

[0043] It may be provided that at least one locking system of at least one tension band system is in contact with a clamping plate in the assembled state of the stack of electrochemical units.

[0044] In this case, it is particularly advantageous if all locking systems of all tension band systems are in contact with one of the clamping plates of the electrochemical device when the stack of electrochemical units is assembled.

[0045] Alternatively or additionally, it may also be provided that at least one locking system of at least one tension band system is arranged in the assembled state of the stack of electrochemical units in the area of ​​one longitudinal side of the stack of electrochemical units, spaced apart from the clamping plates.

[0046] In a particular embodiment of the invention, it is provided that all locking systems of all tension band systems are arranged in the assembled state of the stack of electrochemical units in the area of ​​one longitudinal side of the stack of electrochemical units, spaced apart from the clamping plates.

[0047] Alternatively or additionally, the problem underlying the invention in a method for clamping a stack of electrochemical units with the features of the preamble of claim 8 is also solved according to the invention by holding the clamping plates in position parallel to each other during the tightening of the clamping elements of the locking systems of the clamping band systems.

[0048] Because the clamping plates are held in a plane-parallel position relative to each other during the tightening of the clamping elements of the locking systems, tilting of the clamping plates relative to each other is reliably prevented.

[0049] By fixing the clamping plates in their plane-parallel position, the ends of the clamping bands of the clamping band systems of the clamping device slide along the surface of the clamping plates in the event of an uneven load, in order to reduce the force difference that occurs.

[0050] It may be provided that the clamping plates are held in position parallel to each other by means of one or more clamping devices during the tightening of the clamping elements of the locking systems of the tension band systems.

[0051] For example, it may be provided that a first clamping device forcibly holds a first clamping plate in a predetermined orientation and a second clamping device forcibly holds a second clamping plate in a position parallel to the orientation of the first clamping plate.

[0052] Alternatively or additionally, the problem underlying the invention in a method for clamping a stack of electrochemical units with the features of the preamble of claim 8 is also solved according to the invention by preforming at least one adaptation area of ​​at least one clamping band of at least one clamping band system before tightening the at least one clamping element of the clamping band system in such a way that the clamping band, taking into account an outer radius of an edge region of at least one clamping plate and / or taking into account a distance Δ between the clamping plates, already bears substantially flat against at least one of the clamping plates in the clamped state of the stack of electrochemical units before tightening the at least one clamping element.

[0053] By adapting the at least one tension band to the geometry of the clamping plate against which the at least one locking element rests in the clamped state of the clamping device (in particular with regard to the outer radius of an edge region of the clamping plate in question and / or a distance between the outer radii of the edge regions of the clamping plates), as well as to the height of the stack of electrochemical units in the clamped state, which corresponds to the distance Δ between the clamping plates in the clamped state of the stack of electrochemical units, a more homogeneous introduction of the frictional force into the clamping plate, to whose geometry an adaptation has been made, occurs when the at least one tensioning element of the clamping band system in question is tightened, thereby reducing a tilting of this clamping plate relative to the other clamping plate.

[0054] It is particularly advantageous if at least one tension band system includes two or more locking systems.

[0055] The method according to the invention is preferably carried out using a clamping device according to the invention.

[0056] The clamping device according to the invention is preferably used according to the method according to the invention.

[0057] The clamping device according to the invention is particularly suitable for clamping a stack of electrochemical units which are part of an electrochemical device.

[0058] The electrochemical device may in particular be a fuel cell device (for example, a polymer electrolyte membrane fuel cell device), an electrolyzer or an electrochemical compressor.

[0059] Further features and advantages of the invention are the subject of the following description and the graphic representation of exemplary embodiments.

[0060] The drawings show: Fig. 1 a schematic side view of a stack of electrochemical units arranged along a stacking direction and between two clamping plates, and a clamping device for clamping the stack of electrochemical units between the clamping plates, the clamping device comprising one or more clamping band systems, wherein each tension band system comprises a tension band having a first tension band end and a second tension band end, and a locking system for connecting the first tension band end of the tension band to the second tension band end of the same tension band, wherein the locking system comprises a first locking element which is in contact with the first tension band end, a second locking element which is in contact with the second end of the tension band, and a tensioning element for tensioning the first locking element and the second locking element comprises, wherein each of the tensioning band systems comprises a tensioning element which is designed as a tensioning screw, and wherein all tensioning band systems of the tensioning device have a common direction of rotation which is directed from a first tensioning band end of a first tensioning band system to a second tensioning band end of the same tensioning band system which is tensioned with the first tensioning band end by means of the tensioning element, with the viewing direction perpendicular to the stacking direction and perpendicular to the common direction of rotation of the tensioning band systems; Fig. 2 a schematic longitudinal section through a locking system of a tension band system of the electrochemical device Fig. 1, parallel to a longitudinal median plane of the locking system aligned parallel to the stacking direction and parallel to the common direction of rotation; Fig. 3 a perspective view of a locking system of the electrochemical device arranged on a clamping plate from the Fig. 1 and Fig. 2; Fig. 4 a perspective view of a stack of electrochemical units arranged along a stacking direction and between two clamping plates, and a clamping device for clamping the stack of electrochemical units, wherein the clamping device comprises four clamping band systems, each comprising a clamping element in the form of a clamping screw, wherein the clamping screws of a first clamping screw group have a first shaft direction aligned parallel to the common direction of rotation and the clamping screws of a second clamping screw group have a second shaft direction aligned antiparallel to the common direction of rotation, wherein the first tensioning screw group and the second tensioning screw group each comprise two tensioning screws and wherein the sequence of tension band systems of type A comprising a tension screw of the first tension screw group and of tension band systems of type B comprising a tension screw of the second tension screw group is formed in a transverse direction perpendicular to the common direction of rotation and perpendicular to the stacking direction in a mirror-symmetrical manner with respect to a longitudinal median plane of the stack of electrochemical units oriented parallel to the common direction of rotation and parallel to the stacking direction; Fig. 5 a perspective view of an electrochemical device comprising a stack of electrochemical units arranged along a stacking direction and between two clamping plates, and a clamping device for clamping the stack of electrochemical units, wherein the tensioning device comprises four tensioning band systems, each of which comprises a tensioning element in the form of a tensioning screw, wherein the clamping screws of a first clamping screw group have a first shaft direction aligned parallel to a common direction of rotation of all clamping band systems and the clamping screws of a second clamping screw group have a second shaft direction aligned antiparallel to the common direction of rotation, wherein the first clamping screw group and the second clamping screw group each comprise two clamping screws and wherein, along a transverse direction perpendicular to the common direction of rotation and perpendicular to the stacking direction, a clamping band system of type A comprising a clamping screw of the first clamping screw group and a clamping band system of type B comprising a clamping screw of the second clamping screw group alternately follow one another; Fig. 6 a perspective view of a third embodiment of an electrochemical device comprising a stack of electrochemical units arranged along a stacking direction and between two clamping plates, and a clamping device for clamping the stack of electrochemical units, wherein the clamping device comprises three clamping band systems, each clamping band system comprising a clamping element which includes a clamping screw, wherein the tensioning screws of a first tensioning screw group have a first shaft direction aligned parallel to the common direction of rotation of all tensioning band systems and the tensioning screws of a second tensioning screw group have a second shaft direction aligned antiparallel to the common direction of rotation, wherein the first tensioning screw group comprises two tensioning screws and the second tensioning screw group comprises one tensioning screw and wherein the sequence of tension band systems of type A, comprising a tension screw of the first tension screw group, and of the tension band system of type B, comprising a tension screw of the second tension screw group, is designed in a mirror-symmetrical manner to the tension band system of type B, comprising a tension screw of the second tension screw group, where the clamping screw of the second clamping screw group can transmit a higher clamping force than the clamping screws of the first clamping screw group; Fig. 7 a schematic longitudinal section through a locking system of a tension band system of a tensioning device for clamping a stack of electrochemical units in a fourth embodiment of the invention, in which each of the tension band systems comprises a clamping element which includes a clamping screw which is provided with a left-hand thread section which engages in a complementary left-hand thread of a first locking element and with a right-hand thread section which engages in a complementary right-hand thread of a second locking element, parallel to a longitudinal median plane of the locking system which is aligned parallel to a common direction of rotation of the tension band systems and parallel to the stacking direction; Fig. 8 a schematic longitudinal section through a locking system of a tension band system of a tensioning device for tensioning a stack of electrochemical units in a fifth embodiment of the invention, in which each of the tension band systems comprises a tensioning element which has a tensioning screw and a tensioning nut arranged on the tensioning screw, wherein a shaft of the clamping screw extends through a first through hole in a first locking element and through a second through hole in a second locking element, wherein the clearance of the locking screw in the second through hole is greater than in the first through hole; Fig. 9 a schematic side view of an electrochemical device comprising a stack of electrochemical units arranged along a stacking direction and between two clamping plates, and a clamping device for clamping the stack of electrochemical units, wherein the clamping device comprises at least one clamping band system, where each of these tensioning band systems comprises two tensioning bands and two locking systems, wherein each locking system serves to connect a first tension band end of one tension band to a second tension band end of another tension band, wherein each locking system comprises a first locking element which is in contact with a first tension band end, a second locking element which is in contact with a second tension band end, and a tensioning element for tensioning the first locking element and the second locking element comprises, wherein each of the clamping elements comprises a clamping screw and wherein, when clamping the stack of electrochemical units, the clamping elements of all locking systems of each clamping band system are tightened simultaneously or alternately, wherein the locking systems of the tensioning band system are each located against one of the tensioning plates; Fig. 10 one of the Fig. 9. A corresponding side view of an electrochemical device comprising a stack of electrochemical units arranged along a stacking direction and between two clamping plates, and a clamping device for clamping the stack of electrochemical units, wherein the clamping device comprises at least one clamping band system. where each tensioning system comprises two tensioning bands and two locking systems wherein each locking system serves to connect a first tension band end of one tension band to a second tension band end of another tension band, each locking system a first locking element which is in contact with a first tension band end, a second locking element which is in contact with a second tension band end, and a tensioning element for tensioning the first locking element and the second locking element comprises, wherein each of the locking systems comprises a tensioning element which includes a tensioning screw, and wherein the tensioning elements of all locking systems of a tensioning band system are tightened simultaneously or alternately, wherein the locking systems of the tensioning system are arranged laterally next to the stack of electrochemical units and do not rest against any of the clamping plates; Fig. 11 a schematic side view of an electrochemical device comprising a stack of electrochemical units arranged along a stacking direction and between two clamping plates, and a clamping device for clamping the stack of electrochemical units, wherein the clamping device comprises at least one clamping band system, wherein each tension band system has at least one tension band which has a first tension band end and a second tension band end, and comprising at least one locking system for connecting a first tension band end of a tension band to a second tension band end of the same tension band, wherein the locking system each has a first locking element which is in contact with a first tension band end, a second locking element which is in contact with a second tension band end, and a tensioning element for tensioning the first locking element and the second locking element comprises, wherein each of the locking systems comprises a tensioning element which includes a tensioning screw, wherein the clamping plates are held in position parallel to each other by means of clamping devices during the tightening of the clamping elements of the locking systems of the tensioning band systems; and Fig. 12 a schematic side view of an electrochemical device comprising a stack of electrochemical units arranged along a stacking direction and between two clamping plates, and a clamping device for clamping the stack of electrochemical units, wherein the clamping device comprises at least one clamping band system, wherein each tension band system comprises a tension band having a first tension band end and a second tension band end, and a locking system for connecting the first tension band end and the second tension band end, wherein the locking system includes a first locking element which is in contact with the first tension band end, a second locking element which is in contact with the second end of the tension band, and a tensioning element for tensioning the first locking element and the second locking element comprises, wherein the locking system comprises a clamping element which includes a clamping screw, and wherein adjustment areas of the clamping band are pre-bent before tightening the clamping element so that the clamping band, taking into account an outer radius of an edge area of ​​the clamping plates and taking into account the distance Δ between the clamping plates, already lies flat against the clamping plates in the clamped state of the stack of electrochemical units before tightening the clamping element.

[0061] Identical or functionally equivalent elements are designated with the same reference symbols in all figures.

[0062] One in the Fig. The first embodiment of an electrochemical device, designated as a whole by 100, shown in Figures 1 to 4, comprises a stack 102 of electrochemical units 104 which follow one another along a stacking direction 106 and are arranged between two clamping plates 108.

[0063] The electrochemical device 100 can, for example, be designed as a fuel cell device, as an electrolyzer or as an electrochemical compressor.

[0064] Furthermore, the electrochemical device 100 comprises a clamping device 110 for clamping the stack 102 of the electrochemical units 104 between the clamping plates 108, wherein the clamping device 110 comprises one or more clamping band systems 112, in the Fig. The embodiment shown in Figures 1 to 4 comprises four tension band systems 112.

[0065] Each tension band system 112 comprises a tension band 114, which has a first tension band end 116 and a second tension band end 118.

[0066] Each of the tension band ends 116 and 118 can, for example, be designed as a tension band loop 120, wherein an end piece 122 of the respective tension band 114 is returned to a respective assigned fixing section 124 of the respective tension band 114, preferably lying substantially flat against the fixing section 124 and is fixed to the fixing section 124, preferably by a material bond.

[0067] This fixing of the end piece 122 to the respective assigned fixing section 124 of the tension band 114 can be achieved by material bonding, for example by gluing, soldering or welding, and / or by form bonding, for example by clinching or clinching.

[0068] During the Fig. In the embodiment of an electrochemical device 100 shown in Figures 1 to 4, each tension band system 112 comprises a locking system 126 for connecting the first tension band end 116 of the tension band 114 with the second tension band end 118 of the same tension band 114.

[0069] The locking system 126 comprises a first locking element 128, which is in contact with the first tension band end 116, a second locking element 130, which is in contact with the second tension band end 118, and a tensioning element 132 for tensioning the first locking element 128 and the second locking element 130.

[0070] In the illustrated embodiment, the clamping element is designed as a clamping screw 134.

[0071] Each tensioning screw 134 comprises a screw head 136, which may, for example, include an actuating end 138 of the tensioning screw 134 and a thinner head area 140 of the tensioning screw 134, and a shaft area 142, which is provided at least partially with an external thread 144.

[0072] How best to get from the Fig. 2 and Fig. As can be seen in Figure 3, the locking elements 128 and 130 of the locking system 126 in this embodiment of a clamping device 110 are preferably designed as round bolts 146, each of which has a through hole 148 extending in the radial direction of the respective round bolt 146 and arranged axially in the center.

[0073] The shaft area 142 of the tensioning screw 134 extends through both through holes 148.

[0074] The through-hole 148a in the first locking element 128 of the locking system 126 is designed such that its diameter is slightly larger than the outer diameter of the external thread 144 of the clamping screw 134, so that the clamping screw 134 is guided with minimal play in the through-hole 148a of the first locking element 128.

[0075] The through-hole 148b in the second locking element 130, however, is provided with an internal thread 150, which is designed to be complementary to the external thread 144 of the clamping screw 134, so that the external thread 144 of the clamping screw 134 engages in the internal thread 150 of the through-hole 148b in the second locking element 130. This makes it possible to clamp the first locking element 128 and the second locking element 130 against each other by screwing the clamping screw 134 with its external thread 144 into the internal thread 150 of the second locking element 130, thereby shortening the distance between the longitudinal center axes of the first locking element 128 and the second locking element 130.

[0076] The internal thread 150 can be formed integrally with a base body of the second closure element 130 or on a threaded insert which is inserted into the through hole 148b.

[0077] How best to Fig. As can be seen in Figure 3, the first tension band end 116 of the tension band 114 rests against the first locking element 128 over a portion of the cylindrical surface of the first locking element 128. The first tension band end 116 is provided with two through-openings 152a and 152a' through which the tensioning element 130, in the form of the tensioning screw 134, extends when the locking system 126 is assembled.

[0078] In a corresponding manner, the second tension band end 118 rests against the second locking element 130 over a part of the cylindrical surface of the second locking element 130.

[0079] The second end of the tension band 118 has two passage openings 152b and 152b' through which the shaft area 142 of the tensioning element 132, which is designed as a tensioning screw 134 and is provided with the external thread 144, extends in the assembled state of the locking system 126.

[0080] Furthermore, both locking elements 128 and 130 are each provided with a locking device 154 at their frontal or lateral ends.

[0081] Each of the locking devices 154 can, for example, be designed as a cylindrical disc whose outer diameter exceeds the inner diameter of the tension band loop 120 of the first tension band end 116 or of the second tension band end 118, so that the respective tension band end 116, 118 is prevented from sliding down from the respective associated closure element 128, 130 in its axial direction by the locking devices 154 of the first closure element 128 or of the second closure element 130.

[0082] Since the tension bands 114 of the tension band systems 112 do not cover the clamping plates 108 of the electrochemical device 100 across their entire width, several tension band systems 112 are used. In the Fig. In the embodiment of an electrochemical device 100 shown in Figures 1 to 4, these are four tension band systems 112.

[0083] All tension band systems 112 have a common direction of rotation 156, which is directed from a first tension band end 116 of a first tension band system 112a to a second tension band end 118 of the same tension band system 112a, which is tensioned with the first tension band end 116 by means of a tensioning element 132, and is aligned parallel to the longitudinal direction of the tension band 114 of the first tension band system 112a.

[0084] In principle, the common direction of rotation 156 of all tension band systems 112 could also be chosen such that it runs from a first tension band end 116 of another tension band system 112b to a second tension band end 118 of the same tension band system 112b, which is tensioned to the first tension band end 116 by means of a tensioning element 132, and is aligned parallel to the longitudinal direction of the tension band 114 of the second tension band system 112b. In this case, the orientation of the common direction of rotation 156 would be rotated by 180°. The orientation of the common direction of rotation 156 can therefore be chosen arbitrarily; the only important thing is that this orientation is the same for all tension band systems 112 of the tensioning device 110.

[0085] Furthermore, all clamping elements 132 of the locking systems 126 of the tensioning band systems 112 each have a shaft direction 158, which is directed from the screw head 136 of a clamping screw 134 to its shaft end 159 facing away from the screw head 136.

[0086] In known clamping devices 110 for electrochemical devices 100 of the type described above, the screw heads 136 of the clamping screws 134 are always arranged on the same side of the locking systems 126 of the clamping band systems 112, and the shaft ends 159 of the clamping screws 134 facing away from the screw heads 136 are also all arranged on the same side of the locking systems 126 of the clamping band systems 112, so that all clamping screws 134 are screwed into the through hole 148b of the second locking element 130, which is designed as a threaded hole, from the same side.

[0087] Due to such a one-sided screw connection of the tension bands 114 of the tension band systems 112, the geometric boundary conditions and frictional influences result in an uneven force introduction into the clamping plate 108, against which the locking systems 126 of the tension band systems 112 rest.

[0088] This can cause the clamping plates 108 to tilt relative to each other, which means that a homogeneous force transmission into the electrochemically active areas of the electrochemical units 104 of the stack 102 of the electrochemical device 100 is no longer guaranteed. This can impair the electrical performance of the electrochemical device 100 and / or accelerate the degradation of the electrochemical units 104 of the electrochemical device 100.

[0089] To prevent the clamping plates 108 from tilting relative to each other due to one-sided screwing of the inserted clamping bands 114, the following must be done in the Fig. In the embodiment of an electrochemical device 100 shown in Figures 1 to 4, it is provided that the one-sided force application by the tension band 114 of a tension band system 112 is balanced by an opposite one-sided force application by a tension band 114 of another tension band system 112.

[0090] This is necessary for the in the Fig. In the embodiment of an electrochemical device 100 shown in Figures 1 to 4, it is provided that the clamping screws 134 of a first clamping screw group 160a have a first shaft direction 158a aligned parallel to the common direction of rotation 156 and the clamping screws 134 of a second clamping screw group 160b have a second shaft direction 158b aligned antiparallel to the common direction of rotation 156, wherein the first clamping screw group 160a and the second clamping screw group 160b each comprise at least one clamping screw 134.

[0091] During the Fig. In the first embodiment of an electrochemical device 100 shown in Figures 1 to 4, the number of tension band systems 112 is four, i.e., even.

[0092] In this case, it is preferably provided that the first clamping screw group 160a and the second clamping screw group 160b both comprise the same number of clamping screws 134, namely two each.

[0093] The sequence of tension band systems 112, comprising a tension screw 134 of the first tension screw group 160a, and of tension band systems 112, comprising a tension screw 134 of the second tension screw group 160b, is formed in a transverse direction 162 of the stack 102 of electrochemical units 104, perpendicular to the common direction of rotation 156 and perpendicular to the stacking direction 106, and is mirror-symmetric with respect to a longitudinal median plane of the stack 102 of electrochemical units 104, which is aligned parallel to the common direction of rotation 156 and parallel to the stacking direction 106.

[0094] If the tension band systems 112 with tension screws 134 of the first tension screw group 160a are designated as tension band systems 112 of type A and the tension band systems 112 with tension screws 134 of the second tension screw group 160b are designated as tension band systems 112 of type B, then the sequence of the tension band systems 112 along the transverse direction 162 of the stack 102 of electrochemical units 104 in this embodiment is ABBA.

[0095] This symmetrical, reciprocal design of the tension band systems 112 ensures that the inherently one-sided force application of the tension band 114 of a tension band system 112 of type A is balanced by an oppositely one-sided force application of the tension band 114 of a tension band system 112 of type B. Overall, this results in a uniform application of clamping forces through the tension bands 114 into the clamping plates 108, thus preventing tilting of the clamping plates 108 relative to each other when clamping the electrochemical units 104 of the stack 102 of electrochemical units 104 of the electrochemical device 100.

[0096] One in Fig. The second embodiment of an electrochemical device shown in Figure 5 differs from the one shown in the Fig. 1 to 4 of the first embodiment shown, in that the sequence of types of tension band systems 112 along the transverse direction 162 of ABBA (see Fig. 4) in ABAB (see Fig. 5) has been changed.

[0097] In this second embodiment, a tension band system of type A, comprising a tension screw 134 of the first tension screw group 160a, and a tension band system 112 of type B, comprising a tension screw 134 of the second tension screw group 160b, alternate along the transverse direction 162.

[0098] In this embodiment as well, the total number of tension band systems 112 is even, and the number of tension screws 134 in the first tension screw group 160a is the same as the number of tension screws 134 in the second tension screw group 160b.

[0099] In this second embodiment of an electrochemical device 100, tilting of the clamping plates 108 relative to each other during clamping of the stack 102 of electrochemical units 104 of the electrochemical device 100 is thus avoided by compensating the one-sided force application by means of a clamping band 114 of a clamping band system 112 of type A by the oppositely directed one-sided force application by means of a clamping band 114 of a clamping band system 112 of type B.

[0100] Moreover, the in Fig. 5 second embodiment of an electrochemical device 100 with regard to structure, function and method of manufacture with the one described in the Fig. 1 to 4 of the first embodiment shown, to the preceding description of which reference is made.

[0101] One in Fig. The third embodiment of an electrochemical device 100, as shown in Figure 6, differs from the two described in the Fig. In embodiments 1 to 5 shown, the total number of tension band systems 112 of the tensioning device 110 is odd, so that the first tensioning screw group 160a and the second tensioning screw group 160b comprise a different number of tensioning screws 134.

[0102] At the in Fig. In the embodiment 6 specifically illustrated, it is provided that along the transverse direction 162 of the stack 102 of electrochemical units of the electrochemical device 100, a tension band system 112 of type A, a tension band system 112 of type B and a tension band system 112 of type A follow one another. The sequence of the types of tension band systems 112 along the transverse direction 162 is therefore ABA.

[0103] In this embodiment, the first clamping screw group 160a thus comprises two clamping screws 134, while the second clamping screw group 160b comprises only one clamping screw 134.

[0104] In order to nevertheless achieve at least an approximate balance of forces between the forces introduced into the clamping plates 108 by the tension band systems 112 of type A on the one hand and the forces introduced into the clamping plates 108 by the tension band system 112 of type B on the other hand, the tension band system 112 of type B is designed in relation to the tension band systems 112 of type A such that the locking elements 128 and 130 of the tension band system 112 of type B can be clamped against each other with an increased clamping force.

[0105] This can be achieved, for example, by the tension band 114 of the tension band system 112 of type B having a greater width (i.e. a greater extent along the transverse direction 162 of the stack 102 of electrochemical units 104) than the tension bands 114 of the tension band systems 112 of type A.

[0106] For example, it can be provided that the width B is at least 10%, preferably at least 20%, particularly preferably at least 30% larger than the width b of a tension band 114 of one of the tension band systems 112 of type A.

[0107] Alternatively or additionally, it may be provided that the tensioning screw 134 of the tensioning band system 112 of type B has a larger shaft diameter than the tensioning screws 134 of the tensioning band systems 112 of type A.

[0108] For example, it can be provided that the outer diameter D of the external thread 144 of the clamping screw 134 of the tensioning band system 112 of type B is at least 10%, preferably at least 20%, particularly preferably at least 30% larger than the outer diameter of the external thread 144 of a clamping screw 134 of one of the tensioning band systems 112 of type B.

[0109] Furthermore, alternatively or additionally, it may be provided that the locking elements 128 and 130 of the tension band system 112 of type B have a larger shell diameter than the locking elements 128 and 130 of the tension band systems 112 of type A.

[0110] For example, it may be provided that the shell diameter M of the locking elements 128 and 130 of the tension band system 112 of type B is at least 10%, preferably at least 20%, particularly preferably at least 30% larger than the shell diameter m of the locking elements 128 and 130 of the tension band systems 112 of type A (measured in each case in the area between the locking devices 154).

[0111] The clamping screw 134 of the clamping screw group 160b, which comprises a smaller number of clamping screws 134, thus transmits a higher clamping force than any of the clamping screws 134 of the clamping screw group 160a, which comprises a larger number of clamping screws 134.

[0112] At the in Fig. In the third embodiment of an electrochemical device 100 shown in Figure 6, the sequence of tension band systems 112, comprising a tension screw 134 of the first tension screw group 160a, and of tension band systems 112, comprising a tension screw 134 of the second tension screw group 160b, is arranged along the transverse direction 162 of the stack 102 of electrochemical units 104 of the electrochemical device 100, perpendicular to the common direction of rotation 156 of the tension band systems 112, in a mirror-symmetrical manner with respect to the longitudinal median plane of the stack 102 of electrochemical units 104, which is aligned parallel to the common direction of rotation 156 and parallel to the stacking direction 106.

[0113] Moreover, the in Fig. 6 third embodiment of an electrochemical device with regard to structure, function and method of manufacture compared to the one described in the Fig. 1 to 4 of the first embodiment shown, to the preceding description of which reference is made.

[0114] One in Fig. Figure 7 shows a partial illustration of the fourth embodiment of an electrochemical device 100, which differs from the three shown in the Fig. In embodiments 1 to 6 shown, the shaft directions 158 of all clamping screws 134 of all tension band systems 112 of the clamping device 110 can have the same orientation relative to the common direction of rotation 156 of all tension band systems 112.

[0115] In this embodiment, a uniform force application when clamping the stack 102 of electrochemical units 104 of the electrochemical device 100 is achieved by each clamping screw 134 not comprising a one-piece external thread 144 with a single thread rotation direction, but a two-piece external thread 144 comprising a left-hand thread section 164 and a right-hand thread section 166.

[0116] At the in Fig. In the specific embodiment shown in Figure 7, the left-hand thread section 164 of the clamping screw 134 engages with a complementary internal left-hand thread 168 of the through hole 148a in the first locking element 128 of the locking system 126.

[0117] The right-hand thread section 166 engages with an internal right-hand thread 170 of the through hole 148b in the second locking element 130 of the locking system 126.

[0118] Alternatively, the right-hand thread section 166 can be arranged closer to the screw head 136 than the left-hand thread section 164. In this case, the right-hand thread section 166 engages with a complementary internal right-hand thread 170 of the through hole 148a in the first locking element 128, and the left-hand thread section 164 engages with a complementary internal left-hand thread 168 of the through hole 148b in the second locking element 130 of the locking system 126.

[0119] The left-hand thread section 164 and the right-hand thread section 166 of the clamping screw 134 preferably have the same thread pitch in magnitude, but opposite thread rotation directions.

[0120] Thus, when the tensioning screw 134 is turned clockwise into the internal right-hand thread 170 of the second locking element 130 when the first locking element 128 and the second locking element 130 of the locking system 126 are tightened against each other, the left-hand thread section 164 of the tensioning screw 134 is simultaneously turned out of the internal left-hand thread 168 of the first locking element 128, causing the first locking element 128 and the second locking element 130 to move towards each other.

[0121] When the tensioning screw 134 is tightened, the first tensioning band end 116 and the second tensioning band end 118 of the tensioning band system 112 are subjected to a uniform tensioning force. This prevents the clamping plates 108 from tilting relative to each other.

[0122] In principle, it can also be provided that the left-hand thread section 164 and the right-hand thread section 166 of the clamping screw 134 have different amounts of the thread pitch, with opposite thread rotation directions, in order to avoid an otherwise asymmetrical introduction of clamping forces from the clamping band system 112 to the clamping plates 108.

[0123] The internal left-hand thread 168 has the same thread pitch as the left-hand thread section 164 of the tensioning screw 134. Likewise, the internal right-hand thread 170 has the same thread pitch as the right-hand thread section 166 of the tensioning screw 134.

[0124] All tension band systems 112 of the tensioning device 110 of the electrochemical device 100 can have the same structure.

[0125] The orientations of the tensioning screws 134 of the tensioning band systems 112 relative to the common direction of rotation 156 of all tensioning band systems 112 are arbitrary in this embodiment, since the tensioning forces in each individual tensioning band system 112 are balanced on their own.

[0126] Moreover, the in Fig. 7 fourth embodiment of an electrochemical device 100 with regard to structure, function and method of manufacture with the one described in the Fig. 1 to 4 of the first embodiment shown, to the preceding description of which reference is made.

[0127] One in Fig. Figure 8 shows a partial illustration of the fifth embodiment of an electrochemical device 100, which differs from the one shown in the Fig. 1 to 4 of the first embodiment shown, in that the clamping screw 134 of the locking system 126 does not engage in an internal thread 150 of one of the locking elements 128, 130 of the locking system 126, but instead engages with a clamping nut 172, which is arranged on the end region of the shaft of the clamping screw 134 facing away from the screw head 136.

[0128] The clamping nut 172 has an internal thread 174 which is complementary to the external thread 144 of the clamping screw 134.

[0129] The clamping nut 172 can comprise an actuation area 176, on which, for example, a wrench or other actuation tool can engage, and a sleeve area 178, which has a smaller outer diameter than the actuation area 176.

[0130] In the assembled state of the locking system 126, the clamping nut 172 is arranged on one side of one of the locking elements 130 of the locking system 126 facing away from the other locking element 128 and presses this locking element 130 towards the other locking element 128.

[0131] When the first locking element 128 and the second locking element 130 of the locking system 126 are clamped against each other, the clamping screw 134 and the clamping nut 172 are tightened simultaneously or alternately, each by the same angle of rotation. This ensures that both locking elements 128, 130 of the locking system 126, and thus both tension band ends 116, 118 of the tension band system 112, are subjected to a uniform clamping force.

[0132] This prevents the chipboard plates 108 from tilting relative to each other.

[0133] Moreover, the in Fig. Figure 8 shows the fifth embodiment of an electrochemical device with regard to its structure, function and method of manufacture, compared to the one described in the Fig. 1 to 4 of the first embodiment shown, to the preceding description of which reference is made.

[0134] One in Fig. The sixth embodiment of an electrochemical device 100 shown in Figure 9 differs from the one described in the Fig. 1 to 4 of the first embodiment shown, in that each of the tension band systems 112 comprises two locking elements 126.

[0135] Each of these locking systems 126 connects a first tension band end 116 of a first tension band 114 of the tension band system 112 with a second tension band end 118 of a second tension band 114 of the same tension band system 112.

[0136] The clamping screws 134 of the locking systems 126 preferably have the same orientation with respect to the common direction of rotation 156 of all clamping band systems 112 of the clamping device 110 of the electrochemical device 100. Thus, preferably all clamping screws 134 of the locking systems 126 of a clamping band system 112 are aligned with their shank direction 158 parallel to the direction of rotation 156, or all clamping screws 134 of all locking systems 126 of a clamping band system 112 are aligned with their shank directions 158 antiparallel to the direction of rotation 156.

[0137] At the in Fig. In the embodiment of an electrochemical device 100 shown in Figure 9, the locking systems 126 of a tension band system 112 are each in contact with one of the clamping plates 108 of the electrochemical device 100. Preferably, the tension band loops 120 of the first tension band end 116 and the second tension band end 118, which are connected to each other by the respective locking system 126, lie against an outer surface of the respective clamping plate 108, preferably over a substantially flat area.

[0138] When the stack 102 of electrochemical units 104 of the electrochemical device 100 is clamped against each other, all clamping screws 134 of all locking systems 126 of the same clamping band system 112 are tightened simultaneously or alternately by equal angles of rotation of the clamping screws 134 about their respective longitudinal center axis. This ensures that all clamping band ends 116, 118 of the locking systems 126, and thus all clamping bands 114 of a clamping band system 112, are subjected to a uniform clamping force. This prevents the clamping plates 108 from tilting relative to each other.

[0139] Moreover, the in Fig. Figure 9 shows the sixth embodiment of an electrochemical device 100 with regard to its structure, function and method of manufacture, compared to the one described in the Fig. 1 to 4 of the first embodiment shown, to the preceding description of which reference is made.

[0140] One in Fig. The seventh embodiment of an electrochemical device 100 shown in Figure 10 differs from the one shown in Figure 10. Fig. 9 shown sixth embodiment in that the locking systems 126 of a tension band system 112 are not in contact with the clamping plates 108 of the electrochemical device 100, but are arranged in the area of ​​each longitudinal side of the stack 102 of electrochemical units 104, spaced apart from the clamping plates 108.

[0141] In this case, the shaft directions 158 of the locking screws 134 of the locking systems 126 of each tension band system 112 are aligned parallel to the stacking direction 106 of the stack 102 of electrochemical units 104.

[0142] Preferably, in this embodiment it is also provided that the shaft directions 158 of all tensioning screws 134 of the locking systems 126 of the same tensioning band system 112 have the same orientation with respect to the common direction of rotation 156 of all tensioning band systems 112.

[0143] The shaft directions 158 of all tensioning screws 134 of all locking systems 126 of a tension band system 112 are therefore preferably either all parallel to the common direction of rotation 156 or all antiparallel to the common direction of rotation 156 of the tension band systems 112 of the electrochemical device 100.

[0144] Even in this case Fig. In the embodiment shown in Figure 10, when the stack 102 of electrochemical units 104 is clamped, the clamping elements 132 of all locking systems 126 of a clamping band system 112 are tightened simultaneously or alternately by equal angles of rotation of the clamping screws 134 about their respective longitudinal center axis. This ensures that all clamping band ends 116, 118 of all clamping bands 114 of the same clamping band system 112 are subjected to a uniform clamping force.

[0145] This ensures that the clamping plates 108 of the electrochemical device 100 do not tilt relative to each other.

[0146] Moreover, the in Fig. Figure 10 shows the seventh embodiment of an electrochemical device 100 with regard to its structure, function and method of manufacture, compared to the one described in the Fig. 1 to 4 of the first embodiment shown, to the preceding description of which reference is made.

[0147] One in Fig. Figure 11 shows the eighth embodiment of an electrochemical device 100, which is shown during the process of clamping the stack 102 of electrochemical units 104 of the electrochemical device 100 against each other.

[0148] During this clamping process, each of the clamping plates 108 of the electrochemical device 100 is prevented from tilting and held in position by means of a clamping device 180 assigned to the respective clamping plate 108, so that the respective clamping plate 108 remains aligned parallel to the other clamping plate 108.

[0149] This prevents the clamping plates 108 of the electrochemical device 100 from tilting relative to each other during the clamping of the stack 102 of electrochemical units 104, even if the clamping band ends 116, 118 of the clamping bands 114 of the clamping band systems 112 are subjected to different clamping forces during the clamping process.

[0150] By fixing the clamping plates 108 in their plane-parallel constrained position, the clamping band ends 116, 118 slide relative to the clamping plate 108, on which the clamping band ends 116, 118 are arranged, under such an uneven load, in such a way that the difference of the clamping forces acting on the clamping band ends 116, 118 is reduced.

[0151] In this embodiment of an electrochemical device 100, it is therefore not important how the shaft directions 158 of the clamping screws 134 of the locking systems 126 of the various tension band systems 112 of the clamping device 110 of the electrochemical device 100 are aligned relative to each other and relative to the common direction of rotation 156 of all tension band systems 112 of the electrochemical device 100.

[0152] Moreover, the in Fig. Figure 11 shows the eighth embodiment of an electrochemical device 100 with regard to its structure, function and method of manufacture, compared to the one described in the Fig. 1 to 4 of the first embodiment shown, to the preceding description of which reference is made.

[0153] One in Fig. The ninth embodiment of an electrochemical device 100 shown in Figure 12 differs from the one shown in the Fig. In the first embodiment shown in Figures 1 to 4, the adaptation areas 182 of the tension bands 114 of the tension band systems 112 of the tensioning device 110 of the electrochemical device 100 are pre-bent before the tensioning screws 134 of the locking systems 126 of the tension band systems 112 are tightened, such that the respective tension band 114, on which such an adaptation area 182 is provided, taking into account an outer radius of an edge region of at least one of the clamping plates 108 and / or taking into account a distance Δ between the clamping plates 108, already bears against at least one of the clamping plates 108, preferably over a surface, before the tensioning screws 134 are tightened, in the tensioned state of the stack 102 of electrochemical units 104.

[0154] In this embodiment of an electrochemical device, the radii of curvature of the clamping bands 114 are adapted to the geometry of the clamping plates 108, taking into account the height Δ of the stack 102 of electrochemical units 104, before the stack 102 of electrochemical units 104 is clamped by tightening the clamping screws 134 of the clamping band systems 112.

[0155] By adapting the clamping bands 114 to the geometry of the clamping plates 108 (in particular to the radii of curvature on the outer surface of the clamping plates 108 and to the distance between these radii of curvature of the clamping plates 108) as well as to the height Δ of the stack 102 of electrochemical units 104 in the clamped state, a more homogeneous frictional force is introduced from the clamping bands 114 into the clamping plates 108 when the locking elements 128, 130 of the locking systems 126 of the clamping bands 114 are clamped, thereby reducing or ideally completely preventing tilting of the clamping plates 108 relative to each other.

[0156] Moreover, the in Fig. Figure 12 shows the ninth embodiment of an electrochemical device 100 with regard to its structure, function and method of manufacture, compared to the one described in the Fig. 1 to 4 of the first embodiment shown, to the preceding description of which reference is made.

Claims

[1] Clamping device for clamping a stack (102) of electrochemical units (104) which follow one another along a stacking direction (106) and are arranged between clamping plates (108), wherein the clamping device (110) comprises at least one clamping band system (112), wherein each tension band system (112) comprises at least one tension band (114) having a first tension band end (116) and a second tension band end (118), and at least one closure system (126) for connecting a first tension band end (116) of a tension band (114) to a tension band end (118) of the same tension band (114) or of another tension band (114), wherein the locking system (126) comprises a first locking element (128) which is in contact with a first tension band end (116), a second locking element (130) which is in contact with a second tension band end (118), and a clamping element (132) for clamping the first locking element (128) and the second locking element (130), wherein each locking system (126) comprises a clamping element (132) which includes a clamping screw (134) which is aligned along a shaft direction (158) directed from a screw head (136) of the clamping screw (134) to a shaft end (159) of the clamping screw (134), and wherein the tension band system (112) or tension band systems (112) have a common direction of rotation (156) which is directed from a first tension band end (116) of a first tension band system (112a) to a second tension band end (118) of the same tension band system (112a), which is tensioned to the first tension band end (116) by means of a tensioning element (132), characterized by , that the clamping device (110) comprises several clamping band systems (112), the clamping screws (134) of a first clamping screw group (160a) have a first shaft direction (158a) aligned parallel to the common direction of rotation (156) and the clamping screws (134) of a second clamping screw group (160b) have a second shaft direction (158b) aligned antiparallel to the common direction of rotation (156), wherein the first tensioning screw group (160a) and the second tensioning screw group (160b) each comprise at least one tensioning screw (134). [2] Clamping device according to claim 1, characterized by , that the first tensioning screw group (160a) and the second tensioning screw group (160b) comprise the same number of tensioning screws (134), wherein, along a transverse direction (162) perpendicular to the common direction of rotation (156), a tension band system (112) comprising a tension screw (134) of the first tension screw group (160a) and a tension band system (112) comprising a tension screw (134) of the second tension screw group (160b) alternately follow one another. and / or wherein the sequence of tension band systems (112) comprising a tension screw (134) of the first tension screw group (116a) and of tension band systems (112) comprising a tension screw (134) of the second tension screw group (160b) is formed in a mirror-symmetrical manner along the transverse direction (162) with respect to a longitudinal median plane of the stack (102) of electrochemical units (104) aligned parallel to the common direction of rotation (156) and parallel to the stacking direction (106). [3] Clamping device according to claim 1, characterized by, that the first tensioning screw group (160a) and the second tensioning screw group (160b) comprise different numbers of tensioning screws (134), wherein the sequence of tensioning band systems (112) comprising one tensioning screw (134) of the first tensioning screw group (160a) and of tensioning band systems (112) comprising one tensioning screw (134) of the second tensioning screw group (160b) is formed in a transverse direction (162) perpendicular to the common direction of rotation (156) in a mirror-symmetrical manner with respect to a longitudinal median plane of the stack (102) of electrochemical units (104) oriented parallel to the common direction of rotation (156) and parallel to the stacking direction (106). [4] Clamping device according to claim 3, characterized by, that the at least one clamping screw (134) of the clamping screw group (160b), which comprises a smaller number of clamping screws (134), transmits a higher clamping force than the clamping screws (134) of the clamping screw group (160a), which comprises a larger number of clamping screws (134). [5] Clamping device according to the preamble of claim 1, characterized by , that at least one tension band system (112) comprises at least one tensioning element (132) which includes a tensioning screw (134) which is provided with a left-hand thread section (164) and with a right-hand thread section (166). [6] Clamping device according to claim 5, characterized by , that the left-hand thread section (164) and the right-hand thread section (166) of the same tensioning screw (134) have different thread pitches. [7] Clamping device according to the preamble of claim 1, characterized by, that at least one tension band system (112) comprises at least one tensioning element (132) which includes a tensioning screw (134) and a tensioning nut (172) arranged on the tensioning screw (134), wherein a shaft of the tensioning screw (134) extends through a through hole (148) in the first closure element (128) and through a through hole (148) in the second closure element (130), wherein a radial play of the tensioning screw (134) in the through hole (148) located closer to the tensioning nut (172) is different from the radial play of the tensioning screw (134) in the other through hole (148). [8] Method for clamping a stack (102) of electrochemical units (104) arranged along a stacking direction (106) and between clamping plates (108) by means of a clamping device (110), wherein the clamping device (110) comprises at least one clamping band system (112), wherein each tension band system (112) comprises at least one tension band (114) which has a first tension band end (116) and a second tension band end (118), and comprising at least one locking system (126) for connecting a first tension band end (116) of a tension band (114) to a second tension band end (118) of the same tension band (114) or of another tension band (114), wherein the locking system (126) comprises a first locking element (128) which is in contact with a first tension band end (116), a second locking element (130) which is in contact with a second tension band end (118), and a clamping element (132) for clamping the first locking element (128) and the second locking element (130), comprises, characterized by , that each clamping element (132) comprises a clamping screw (134) and a clamping nut (172) arranged on the clamping screw (134), wherein the clamping screw (134) and the clamping nut (172) are tightened simultaneously or alternately in opposite directions during the clamping of the first locking element (128) and the second locking element (130). [9] Method according to the preamble of claim 8, characterized by that each tension band system (112) comprises two or more locking systems (126), wherein the tensioning elements (132) of all locking systems (126) of a tension band system (112) are tightened simultaneously or alternately. [10] Method according to claim 9, characterized by , that at least one locking system (126) of at least one tension band system (112) in the assembled state of the stack (102) of electrochemical units (104) is in contact with a clamping plate (108). [11] Method according to one of claims 9 or 10, characterized by, that at least one locking system (126) of at least one tension band system (112) is arranged in the assembled state of the stack (102) of electrochemical units (104) in the area of ​​a longitudinal side of the stack (102) of electrochemical units (104), spaced apart from the clamping plates (108). [12] Method according to the preamble of claim 8, characterized by , that the clamping plates (108) are held in position parallel to each other during the tightening of the clamping elements (132) of the locking systems (126) of the tensioning band systems (112). [13] Method according to claim 12, characterized by , that the clamping plates (108) are held parallel to each other by means of one or more clamping devices (180) during the tightening of the clamping elements (132) of the locking systems (126) of the clamping band systems (112). [14] Method according to the preamble of claim 8, characterized by, that at least one adaptation area (182) of at least one tension band (114) of at least one tension band system (112) is pre-formed before tightening the at least one tensioning element (132) of the tension band system (112) in such a way that the tension band (114) taking into account an outer radius of an edge region of at least one clamping plate (108) and / or taking into account a distance (Δ) between the clamping plates (108) in the tensioned state of the stack (102) of electrochemical units (104) already bears substantially flat against at least one of the clamping plates (108) before tightening the at least one tensioning element (132). [15] Method according to claim 14, characterized by , that at least one tension band system (112) comprises two or more locking systems (126).

Images