The invention relates to an arrangement of electrochemical cells as well as their use and in particular the joining and contact elements of electrochemical cells that are inexpensive and can be automated as a planar cell stack for use in the electrolysis and / or in fuel cells, particularly solid oxide fuel cells (SOFC) or Festoxidelektrolysezellen (SOEC) can be produced. In addition, the invention relates to efficien-th use of a sheet of glass, which adjacent to the addition of

Repeating such electrochemical cells, and the realization of the contact between the electrode and a metallic bipolar plate in the electrochemical cell in the assembly process. Furthermore, the invention relates to a SOFC stack for the production of electricity and heat, as well as SOEC stack for high-efficiency hydrogen or synthesis gas production.

Planar cell stack for use in energy conversion and water

Resource recovery are known from the prior art. In general, a plurality of planar cells to a cell stack (sg stack) combined, in the individual repeating units consisting of the cathode-electrolyte-anode unit (sg cell), bipolar plate (sg interconnector), joining elements and contact elements, along a stacking direction consecutive. The electrical contact between individual repeat is performed by a heat treatment (sg joining procedure). By this electrical connection of the individual cells via the interconnector arrangements, the cells are electrically connected in series, whereby the cell stack can be scaled to a required power.

A repeat unit is to be defined as a stack element here, which assembles at room temperature of individual components (cell, interconnect, joining elements and contact elements) and in the subsequent step for the

Stack structure is used. When used as a fuel cell, the air side of a cell as a cathode side is usually (there runs an oxygen reduction ab) and the fuel gas side as an anode side (there runs a hydrogen oxidation ab), respectively. When used as an electrolyser, the air side becomes the anode side (there runs from oxidation of oxygen) and the fuel gas side to the cathode side (there runs reduction of hydrogen from the water vapor).

From the prior art, several variations to the structure of such repeating units for use as a fuel cell are known (US

2003/0235746 Al, DE 103 30 476 B4, DE 103 50 478 B4, EP 2132814 Bl, WO 2008/022638 Al). The cohesive and gas-tight connection of the cell to the interconnector (sg internal addition) and the sealing of the fuel gas and possibly air spaces (manifolds) for connection of the individual repeating units (external addition) in this description and in the one-relevant literature is considered separately.

The analysis of the mentioned documents shows that essentially as described in US 2003/0235746 Al, the integration of the cell with multi-layer interconnect (internal addition). An interconnector consists of four metallic frame. The particular cell is connected to a frame by means of glass solder. This structure is then coated with cathode and Anodenkontaktele-

elements provided (in the form of webs), thus completing the repetition. The gas spaces of the repeating units are sealed by further Glaslotlagen (external addition). Thus, two Glaslotlagen different thicknesses and in different stack levels are not-agile, in this structure, which makes it difficult for cost effective manufacturing of such Widerholeinheiten.

In DE 103 30 476 B4, in particular 2 shows a structure of a repeat unit is described in which at least two Glaslotteile different thickness must be applied to one side of the repeat unit. This requires the use of Glaslotfolien with different thickness and at least two application steps.

In DE 103 50 478 B4, a structure is described in which a cell to a metallic housing partially sintered (internal addition by sintering of the cell with the interconnector) is. Thereafter, the contact elements and joining elements are deposited and formed by the repeating units to the manufactured part. A significant disadvantage of this solution consists in an additional heat treatment step for the cell to sinter to the metal housing.

In EP 2132814 Bl a process for efficiently contacting the cell with the interconnector described (internal addition), the Glaslotteile must be placed on only one side of the interconnector for internal addition. An external addition is not described therein. A one-sided application of the Glaslotteile is particularly thick at joining elements (thickness> 0.4 mm) problematical and requires multiple coating or laminating the multiple Glaslotfolien each other, resulting in additional costs.

In WO 2008/022638 Al the integration of the cell is described having a multilayer interconnect substantially joining said inner and outer addition can be realized at the same time, since the electrolyte size and shape is equal to the size of the metal frame. This structure with respect to the scaling of the outside due to the difference in thermal

Expansion of the electrolyte material and the metallic interconnector limited. In general, the cell size (cell size is given by the external dimensions of the cell) smaller than the size of the metallic

Interkonnektors.

Starting from this prior art, there is still a need to optimize the structure of the repeating units in which the respective size of the surface of a planar cell is less than the area of

is the interconnector. This concerns in particular the number of the joining members used and the need for their application and bonding steps. For this it is best if Glaslotteile uniform thickness can be used for exterior and interior additions regardless of the final thickness of the recurring units. It is of advantage that they can be symmetrically applied to both surfaces of the interconnector (uniform Appllikationstechnologie).

It is therefore an object of the invention to manufacture, in particular to simplify the assembly and the joining of arrays of electrochemical cells and to achieve high tightness against the ambient atmosphere permanently.

According to the invention this object is achieved with an arrangement having the features of claim 1. Uses are indicated in claim 12th Advantageous embodiments and developments of the invention can be realized with designated in the subordinate claims.

The inventive arrangement of electrochemical cells that are superposed and connected electrically conductively to one another is formed with recurring units. The repeating units consist of at least one interconnector, an electrochemical cell, which in turn each formed of a cathode, an electrolyte and an anode. In the interconnectors openings for the gas guide are formed. Further

Elements of a repeating unit are contact elements on the anode side and cathode side.

The electrolytes are flush with in each case from a plane of a surface of the respective interconnector. At that surface of the interconnector one seal layer of a glass solder is applied with a constant thickness each. This single sealing layer sealing the gap between the electrolyte and the interconnector, the so-called inner dispensation and sealing of the gaps between the openings for the gas passage of two adjacent interconnects, the so-called external addition can be achieved.

In the invention, the outer and inner joint with only a single sealing layer of a glass solder having a constant thickness is thus achievable, which is formed on a surface of a respective interconnector.

The arrangement may be closed at one end face by a cover plate and at the opposite end with a base plate.

In addition, the outer edges of the individual electrolytes of the electrochemical cells can be flush with a surface of the edges of an in

complete interconnector formed cathode depression.

Areas in which is formed channels for the gas passage, in particular for the supply of oxidant (eg air) and fuel (eg hydrogen) and the discharge of exhaust gas, and the region in which is arranged a contact element of one of the electrodes of the electrochemical cell at the surface to be sealed is should be kept free of glass solder.

The invention will be described by way of example for the configuration of a cell stack as a fuel cell for electrochemical application (= cathode side air side, the anode side = fuel gas side). The cell stack can also be used for electrolysis, while air side becomes the anode side and the fuel gas side to the cathode side.

They show:

Figures 1 and 2 in a perspective and a sectional view showing the basic structure of a repeat unit;

3 shows in a perspective and a sectional view showing the basic structure of a repeating unit with Glaslotfolienelementen in the green state, at two oppositely disposed surfaces of a repetition unit, with which the gasket layers are formed;

Figure 4 possible configurations and arrangements of Glaslotfolienelementen in a plane on a surface of a repeat unit;

Figure 5 is a cross sectional view showing an example of arrangement according to the invention and

Figure 6 is a perspective sectional view showing an example of an inventive arrangement.

Figures 1 and 2 show the structure of repeating units, as they are known and can be used in the invention. In this case, an interconnect 400 is present, the greater surface area as a unit, which is formed with a cathode 120 and an anode 130 between which a suitable electrolyte 110 is disposed. In the area of ​​the cathode-electrolyte-anode unit (CEA) is a cathode recess 410 in the interconnector 400 into which the KEA can be used, so that at least the electrolyte 110 with its outer lateral sides rests against the interconnector material. In the area of ​​the cathode recess 410 elevations and depressions form gas channels may pass through the oxidizing agent to the cathode 120th

may be in the perspective views of Figures 1 and 2 410 is not designated recesses are adjacent the cathode depression shown, form the channels and the supply of oxidizing agent (in particular air), or a fuel or discharge of the exhaust gas take place.

With Figure 2 will be also shown how a sealing layer 500 is formed on the surface of the interconnector 400 and connected thereto. The sealing layer 500 in this case has recesses which allows accessibility of the anode 130 and the channels for oxidant, fuel or exhaust gas.

With figure 4 it is clear that the 4 material fit to be connected to the gasket layer on the two opposite surfaces of an interconnector can be formed with a plurality of Glaslotfolienelementen 510, 520, 530 and 540th The Glaslotfolienelemente 510, 520, 530 and 540 abut each other and thereby with the end faces so as to form a closed sealing layer 500 to the anode 130 and the channels.

Possible geometric shapes and arrangements of Glaslotfolienelementen 510, 520, 530 and 540 are shown in FIG. 4

An example of an inventive arrangement is shown in the partial sectional view of FIG. 5 Three repeat units of a cover plate 700 are enclosed on one end side and a base plate 800 on the oppositely disposed front side and it can there as a fluid-tight seal with cover plate 700 and base plate 800 can be achieved. Both plates 700 and 800 may be made of an electrically conductive material.

It is also clear that the seal between repeating units each having a sealing layer 500, the one with a surface

Interconnector 400 of a repeating unit having a sealing layer 500 that an immediately neighboring repeat unit is integrally bonded to a surface of an interconnector 400 can be achieved.

From the figures 5 and 6 it is also clear that the size of the surfaces of the electrochemical cells, so the CER's is smaller than the surface area of ​​the interconnectors 400th

6 shows a completed assembly prepared by a heat treatment is shown in which each of a sintered sealing layer 550 is present between the adjacent repeating units, which are connected cohesively 400 with the respective surfaces of the respective interconnectors. In addition, cathode-side contact elements 200 and anode-side contact elements 300 are visible, with which an electrical current flow through gas supply structure in which the oxidant and fuel to the electrodes can reach 120 and 130, 120 and 130 reaches to the respective interconnector 400 from the electrodes.

A uniform total thickness of the Glaslotfolienelemente 510-540 may be used only planar surfaces to be bonded together when two plane. Of the invention is based approach is also that the connection of an electrochemical cell as occurs 100 with an interconnector 400 such that a surface of the electrolyte 110 of a cell 100 forms a flush planar level with one of the interconnector surface consists (see example in FIG. 1). For this purpose, the respective cathode contact member 300, cathode 130 and electrolyte 110 in a katho-denseitigen recess 410 of the respective interconnector may be added 400th The oppositely disposed surface of the interconnector 400 has no recess and Glaslotfolienelemente 510-540 120 need only bridge the anode-side contact member 300 and the thickness of the anode (in this case <50 μιη). For thin anode-side contact elements 200 (<100 μιη), for example, screen printing or mask printing for the application of the glass solder uniform thickness on the opposite surface of the interconnector 400 can be used for joining.

In the application of the elements on Glaslotfolie aids are currently used to the manufacture of a surface Glaslotfolienteile

stick on the interconnector or surfaces of the electrochemical cell manually. Here, a geometrically precise placement is difficult and usually reachable only with tools or very rigid correspondingly thick Glaslotfolien that are very time-consuming. The application of the Glaslotfolienelemen-th 510-540 can be taken in the invention of a semi-automatic machine in which the punching process and the application are carried out successively. By punching the Glaslotfolienelemente 510-540 and fixing on the die of a punch which have Glaslotfolienelemente 510-540 a very high accuracy in shape and position. Since the application process by a programmed robot gripper can, which may be connected directly to the serving for stamping part of the semi-automatic preferably automatically operating machine, no positioning or the magazining Glaslotfolienelemente must be 510-540. The Glaslotfolienelemente 510-540 can thus be positioned with micrometer accuracy. Any disadvantages caused by an additional handling of punched Glaslotfolien can thereby be avoided.

In general, the anode-side contact member 300 has a thickness of 0.3 mm to 0.5 mm. The thickness of the anode-side contact member 200 ultimately determines the overall thickness of an electrochemical cell 100 after joining at a selected example. The to be joined together elements have in the unsintered (sg "green") state, taking account of approximately 50% prior to sintering shrinkage has a total thickness of approximately 0.6 to 1.0 mm. In this thickness range, it is useful, for use add Glaslotfolie. in principle, it is technically possible to make the Glaslotfolienelemente 510-540 in this large magnitude by tape casting. However, the permissible thickness tolerances of approximately +/- 10 μιη are in the dried state hardly attainable. For this reason, it is more cost effective the Glaslotfolienelemente 510-540 having a thickness of 0.25 mm to max. manufacture 0.45 mm by tape casting and another to laminie-ren. Thus, would be in unilateral edition two to four laminating steps, with which the individual Glaslotfolien be interconnected required

borrowed. To ensure that this effort is avoided Glaslotfolienelemente to 510-540 symmetrically on opposite surfaces of the

are placed interconnector 400 (see. Fig. 2 and Fig. 3). Here Glaslotfolienelemente 510-540 can with mutually different (sg com-plementary) thickness tolerances, as occur in different batches Foliengießprozess used and thus Committee be significantly reduced in the Glaslotfolien production. Furthermore, the Glaslotfolien from simple ingredients may be assembled and thus Committee may be reduced when punching the joining parts.

Figure 4 shows the geometry and thickness of the Glaslotfolienelemente 510, 520, 530 and 540, which can be used for a sealing layer 500 when the thickness of the anode-side contacting μιη 350 and anode thickness 50 should be μιη. The Glaslotfolienelemente 510, 520, 530 and 540 are punched out from μιη green glass sheet having a thickness of 350 +/- 20 and automatically in the subsequent step on a surface of a preassembled repeat (Fig. 3) is placed. The Glaslotfolienelemente 510, 520, 530, and 540 are previously measured and sorted in thickness classes, so that the sum of the thickness of the superposed Glaslotfolienelemente μιη results in a common joining plane on the two opposite sides 700 +/- 20th

In the illustrated solution, it comes to that joints between individual Glaslotfolienelementen 510, 520, 530 and 540 may occur, which can be closed in the subsequent joining process by viscous flow of the glass solder. it would be advantageous rotation of the interconnector 400 by 180 ° before the same Glaslotfolienelemente 510, 520, 530 and 540 placed on the other side of preassembled repeat. Thus, the joints of the Glaslotfolienelemente are not disposed on the opposite surfaces of the interconnector 400 one above the other (Fig. 5) and can therefore be easily closed during the joining process.

Due to the semi-automatic or automatic application of Glaslotfolien- elements 510, 520, 530 and 540 onto a surface of an interconnector 400 may be achieved an efficient and high quality coating with Glaslotfolien different properties (very soft). In the further process is applied to the oppositely disposed surface of the interconnector 400 the particular electrochemical cell 100 having its Ano-denkontaktierung 200th In this composite, the second layer is Glaslotfolienelemente 510-540 rotated by 180 ° by means of semi-automatic or automatic Glaslotfolienappliziermaschine applied. A manual Glaslotfolienapplikation on these composite can, for technical reasons and temporal advantageously semi-automatically or fully automatically.

The repeating units are stacked one above the other and with the top plate 700 and base plate 800 is provided (Fig. 5). Subsequently, the cell stack (Stack) is joined cohesively and sealed with a heat treatment using the glass solder. Here, the contact between the anode 120 of the cell 100 and the anode contact element 200 as well as the serial

Interconnection of the cells 100 to each other realized, as shown in FIG. 6 After an electrochemical initialization procedure is the cell stack (stack), which is formed with a plurality of stacked repeating units, ready for use as a fuel cell or electrolyser.

Reference numeral directory:

100 electrochemical cell

110 electrolyte

120 cathode

130 Anode

200 cathode contact element / air side

300 anode contact element / gas side

400 interconnector with / without protective layer

410 cathode depression

500 seal layer of glass solder in the green state

510 Glaslotfolienelement

520 Glaslotfolienelement

530 Glaslotfolienelement

540 Glaslotfolienelement

550 sealing layer in the joined state

600 spacer plate

700 cover plate

800 base

claims

1. An arrangement of electrochemical cells that are superposed and electrically connected with each other, thereby repeating units from at least one interconnector (400) are formed in the openings for the gas passage, an electrochemical cell (100), which (from a cathode 120), an electrolyte (110) and an anode (130) is formed, contact elements on the anode side (300) and the cathode side (200) are formed, are superposed and

the area of ​​each planar electrochemical cell (100) is respectively smaller than the area of ​​the individual interconnectors (400), and

complete the electrolyte (110) aligned respectively with a plane of a surface of the respective interconnector (400) and on this surface of the interconnector (400) each have a single sealing layer (500) of a glass solder having a constant thickness,

for sealing the gap between the electrolyte (110) and the interconnector (400) (internal addition) and the gaps between openings for gas guidance of two adjacent interconnects (400) (external addition),

is attached.

2. Arrangement according to claim 1, characterized in that the arrangement at one end face by a cover plate (700) and at the opposite end with a base plate (800) is closed.

3. Arrangement according to claim 1 or 2, characterized in that the electrochemical cells of the respective surface in a

formed interconnector (400) cathode depression (410) are arranged and / or the sealing layers areas in which a contact element (200 or 300) as well as spaces in which kept free channels for the supply of an oxidizing agent, or fuel, or the discharge of exhaust gas from glass solder.

4. Arrangement according to one of the preceding claims, characterized in that the seal layers (500) with Glaslotfolienelemen- th (510, 520, 530 and 540) are formed.

5. An arrangement according to one of the preceding claims, characterized in that sealing layers (500) on at least one surface, preferably two opposite surfaces of the repeating units are each formed with a constant thickness.

6. Arrangement according to the preceding claim, characterized in that sealing layers (500) have a maximum thickness deviation of 20%.

7. An arrangement according to one of the preceding claims, characterized in that sealing layers (500) have on oppositely disposed surfaces of the individual recurring units respectively have different thicknesses, wherein the thickness of the individual gasket layers (500) is constant, and preferably at the opposite surfaces of a repeating unit formed gasket layers (500) in front of a leading to the sintering heat treatment, a deviation of their respective thickness have <20%.

8. An arrangement according to any one of the preceding claims, characterized in that the Glaslotfolienelemente (510, 520, 530 and 540) a gasket layer (500) abut directly against one another joints.

9. An arrangement according to any one of the preceding claims, characterized in that Glaslotfolienelemente (510, 520, 530 and 540), the seal layers (500) with a constant thickness to form two contact points on opposite surfaces of a repetition unit, the offset locally relative to one another perpendicular to the seal layer plane are.

10. The arrangement according to the preceding claim, characterized in that identically designed in each case Glaslotfolienelemente (510, 520, 530 and 540) are arranged rotated in two on opposite surfaces of a repetition by 180 ° to each other.

11. An arrangement according to any one of the preceding claims, characterized in that the glass film elements (510, 520, 530 and 540) are designed for a fully automatic assembly by robot.

12. Use of an arrangement according to one of the preceding claims as a fuel cell and / or electrolyser.