RU194839U1 - OPEN Cathode Regenerative Fuel Cell - Google Patents

Abstract

The utility model relates to the field of electrical engineering, in particular, to a system for generating electricity and storing hydrogen containing a battery of regenerative fuel cells (BRTE) with a solid polymer electrolyte. The technical result of the claimed utility model is that the design and principle of operation of the RTE allows the transition between operating modes only by changing the direction of the current. To achieve this result, an open cathode regenerative fuel cell is proposed, consisting of at least two connected fuel cells, including corrugated oxygen / air collector, oxygen / air gas diffusion layer, membrane-electrode unit (OIE), connected in series in which there is a hydrogen gas diffusion layer and a hydrogen grid collector, a bipolar plate, while the connected fuel cells of the fuel cell are installed between the end plates itami and are separated from them by collector plates. 1 ill.

Description

Technical field

The utility model relates to the field of electrical engineering, in particular to regenerative fuel cells (RTE), which combine the functions of both fuel cells (TE) and electrolytic cells (EL).

State of the art

Known applications for inventions in which fuel cell designs are proposed with an air supply to the cathode JP 2008516407 and WO 2008038032

In the application JP 2008516407, during operation of the FC, the cathode was in contact with a stationary air atmosphere.

WO2008038032 proposes a method and device for an open cathode fuel cell battery. The fuel cell unit has a cathode air intake and a cathode exhaust.

The disadvantage of these devices is their use only in the design of fuel cells.

A device is known, described in patent US 6833207, with a regenerative fuel cell, which combines the fuel cell unit and the cell unit in one battery with a common system of supply and output of reagents

The disadvantage of this device is its use in the RTE system, in which the electrolyzer and fuel cells are separate electrochemical devices that are combined only with a reagent input / output system. In addition, the reagent input and output system is complex, and assumes that all reagents pass through the TE and EL channels simultaneously.

An invention is known in which the “Regenerative Fuel Cell / Electrolyzer Unit” installation is proposed, consisting of alternating “electrolyzer-TE” units. Application US 20070116996. A conductive plate is located between the electrode assembly of the TE and the electrode assembly of the electrolyzer. When the system is in TE mode, hydrogen-containing gas is supplied from the hydrogen storage unit and oxygen-containing gas from the oxygen storage unit. The oxygen-containing substance may be gaseous oxygen, oxygen enriched gas, air, etc.

The disadvantage of this invention is the use of individual blocks of the electrolyzer and fuel cell and the associated need for complex electrical switching and input-output systems of reagents.

A device is known, described in US patent 7014953, published 2006-03-21, which proposed the design of a regenerative bipolar fuel cell (RBTE). RBTE includes a bipolar plate, hydrogen electrodes in contact with a stream of hydrogen, and oxygen electrodes in contact with a stream of oxygen or air. The gas separation electrolyte chambers are in contact with a hydrogen electrode on the one hand, and with an oxygen electrode on the other. Electrolyte chambers provide mechanical support for FCs and provide contact with a hydrogen electrode and an oxygen electrode. Bipolar plates are located between the hydrogen electrode and the oxygen electrode. The bipolar plate has a hydrogen side in contact with the hydrogen electrode and an oxygen side in contact with the oxygen electrode. The bipolar plate does not require support frames for RBTE electrodes and ensures the integrity of the various parts of the electrodes, while maintaining the availability of various reagents to them. The bipolar plate acts as a manifold for gas distribution and a gasket for sealing.

This device solves the problems of reducing the efficiency of regenerative fuel cells due to current losses at the contacts. This is achieved through the arrangement of bipolar plates and electrodes, which includes internal electrical connections to provide short and efficient current collector leads, creating an improved connection between the plates when changing the size of the electrodes during RHTE operation.

The mixture of gaseous oxygen and water obtained in the water electrolysis mode, enters the reservoir through the valve, where they are separated. Oxygen is sent to an oxygen cylinder, water - to a water storage tank. Hydrogen obtained during electrolysis is separated in the separator from water and enters the reservoir for storing hydrogen, water from the separator is transferred to the reservoir for storing water.

The disadvantage of the invention is the closed cathode and the operation in the FC mode only on oxygen, in this case the FC operates at the limit of its power, which leads to a reduction in the life of the RBTE, while the water generated on the oxygen electrode has a large excess of gaseous oxygen that has not reacted in the reaction.

Utility Model Disclosure

The technical problem to which the claimed utility model is directed is to increase the reliability and efficiency of the RTE and simplify the systems associated with ensuring its operation.

The technical result of the claimed utility model is that the design and principle of operation of the RTE allows the transition between operating modes only by changing the direction of the current.

The technical result of the claimed utility model is achieved by

that the open cathode regenerative fuel cell consists of at least two connected fuel cells, including a corrugated oxygen / air collector, an oxygen / air gas diffusion layer, a membrane-electrode block (OIE), in a frame in which are located a hydrogen gas diffusion layer and a hydrogen grid collector, a bipolar plate, while the connected fuel cells of the fuel cell are installed between the end plates and are separated from them by current collection plates astinami.

The combination of the above essential features leads to the fact that

a transition between operating modes is possible only by changing the direction of the current;

significantly simplifies the system associated with the operation of the RTE and the input - output of reagents;

water circulation in the hydrogen generation mode is carried out only through the channels of the hydrogen electrode, while the channels of the oxygen electrode are open to the atmosphere.

Brief Description of the Drawings

The figure shows a diagram of an RTE battery, consisting of a sequence of cells, the number of which is more than or equal to 2. An RTE battery includes:

1 - end plate;

2 - current collection plate;

3 - corrugated oxygen / air collector;

4 - oxygen / air gas diffusion layer;

5 - membrane-electrode block;

6 - hydrogen gas diffusion layer;

7 - mesh hydrogen collector;

8 - frame;

9 - a sealing ring;

10 - bipolar plate.

Utility Model Implementation

The following is an example of a specific implementation of the device, which does not limit the options for its execution.

A single RTE cell consistently contains: corrugated oxygen / air collector 3, oxygen / air gas diffusion layer 4, membrane-electrode block (OIE) 5, a frame 8 in which there is a hydrogen gas diffusion layer 6 and a mesh hydrogen collector 7, a bipolar plate 10 and o-rings 9.

The fuel cell battery of FIG. Consists of a sequence of unit cells of an RTE, electrically connected and sandwiched between end plates 1 by metal studs, electrically isolated from live parts.

Corrugated oxygen / air manifold 3 is made of corrugated metal tape, for example, of titanium foil, 0.10-0.20 mm thick. The shape is rectangular. The dimensions of the collector correspond to the external dimensions of the frame 8 of FIG. Appointment: current transmission and ensuring the passage of air to the air gas diffusion layer. It is installed between the bipolar plate 10 and the oxygen / air gas diffusion layer 4.

Oxygen / air gas diffusion layer 4 is made of porous carbon-graphite fabric or paper 0.30-0.50 mm thick. The dimensions of the oxygen / air gas diffusion layer correspond to the external dimensions of the frame 8 of FIG. The purpose is to transfer current, as well as to ensure oxygen removal during electrolysis and air supply to the OIE when operating in the FC mode. It is installed between the corrugated oxygen / air collector 3 and the membrane-electrode block 5.

Membrane-electrode block 5, consists of: an Nafion or MF4-SK ion-exchange membrane with a thickness of 50-120 μm with oxygen and hydrogen electrocatalytic layers deposited on both sides based on platinum group metals (platinum, iridium, ruthenium) on carbon or oxide supports. OIE dimensions - according to the external dimensions of the frame 8, the size of the electrocatalytic layers corresponds to the size of the window of the frame 8 of FIG. Appointment: for gas separation, carrying out electrochemical reactions and current transfer. It is installed between the oxygen / air gas diffusion layer 4 and the frame 8.

Hydrogen gas diffusion layer 6, its material: carbon-graphite fabric or paper 0.30-0.50 mm thick. Dimensions of the hydrogen collector - the size of the window frame 8 of FIG. Appointment: ensuring removal / supply of hydrogen and current transfer. It is installed in the window of the frame 8 between the membrane-electrode block 5 and the hydrogen grid collector 7. The hydrogen gas diffusion layer 6 together with the hydrogen grid collector 7 is embedded in the window of the frame 8.

Frame 8, its material is a fluororubber rubber compound. Appointment: fixing of a hydrogen gas diffusion layer 6, a mesh hydrogen collector 7, ensuring sealing of the RTE hydrogen chamber. It is installed between the membrane-electrode block 5 and the bipolar plate 10.

Mesh hydrogen collector 7, its material is a titanium expanded metal mesh in three or more layers. Dimensions - the size of the window frame 8 of Fig. Purpose: current transfer, as well as the removal / supply of hydrogen to the hydrogen gas diffusion layer 6. Installed in frame 8 between the hydrogen gas diffusion layer 6 and the bipolar plate 10.

The bipolar plate 10, the material is a titanium plate with a thickness of 0.30-0.50 mm Dimensions correspond to the external dimensions of the frame 8. Purpose: to separate adjacent cells of the RTE and current transmission. It is installed between the frame 8 and the corrugated oxygen / air collector 3 of the adjacent RTE.

O-ring 9, material - fluororubber rubber. The purpose is to ensure the tightness of the hydrogen channel connecting adjacent RTE cells. It is installed in the holes in the corrugated oxygen / air manifold 3 and the oxygen / air gas diffusion layer 4 for supplying hydrogen.

The RTE battery contains two or more RTEs, current collection plates 2 and end plates 1 pulled together by fasteners, for example, studs.

Current collection plates 2, the material is titanium, the thickness is 1.0-3.0 mm, the thickness depends on the strength of the current supplied or removed from the RTE battery. The dimensions correspond to the external dimensions of the frame 8. Purpose: to ensure the supply / removal of current to the RTE battery. It is installed between the end plate 1 and either the corrugated oxygen / air manifold 3 or the frame 8.

End plates 1, material - metal or hard plastic. Purpose: for fastening RTE cells to the battery using fasteners, for example, threaded rods.

The mesh hydrogen collector 7 forms a volumetric flow channel through which hydrogen is supplied and removed over the area of the RTE cell.

The flow channels for oxygen removal and air supply are formed by a corrugated oxygen / air collector 3. In the power generation mode, air is supplied to the channels either diffusely or using fans. In the hydrogen generation mode, oxygen freely enters the atmosphere. When using fans, the air removes the heat generated during operation of the RTE in all modes.

Internal communications for water supply and hydrogen output in the hydrogen generation mode and hydrogen supply in the electric power generation mode are channels formed when connecting separate parts of the RTE (corrugated oxygen / air collector 3, oxygen / air gas diffusion layer 4, membrane-electrode block 5, frame 8, bipolar plate 10) by making a number of coaxial holes in these parts.

Adjacent RTEs in the battery are separated by a bipolar plate 10 made in the form of a titanium plate 0.5 mm thick. The bipolar plate 10 is in electrical contact with the collectors 3 and 7 and also performs the function of transmitting current. RTE cells with the help of end plates and pins are assembled into an RTE battery.

It is advisable that in the mode of hydrogen generation in the flow channels of the RTE hydrogen electrode, a pressure of up to 1.0 MPa be maintained.

The device operates as follows:

The principle of operation of the RTE is based on the reaction of decomposition of water into hydrogen and oxygen in the mode of hydrogen generation under the influence of direct electric current and the reverse reaction of the recombination of hydrogen and oxygen in the air to form water, in the mode of electricity generation.

As an electrolyte, an ion-exchange membrane is used, which carries out the transport of hydrogen ions and plays the role of a gas separation diaphragm.

RTE operates as follows. In the power generation mode, hydrogen is supplied to the hydrogen electrocatalytic layers of the OIE of the RTE cells through the flow channels, which are formed by the hydrogen grid collector 7, and the air is supplied either diffusely or through fans through the open flow channels of the corrugated oxygen / air collector 3 to the oxygen electrocatalytic layers of the OIE cells RTE. In the hydrogen generation mode, water is supplied to the flow channels formed by the hydrogen grid collector 7, either by means of a circulation pump or by a gas-lift process, due to diffusion passes through a membrane from a solid polymer electrolyte, and enters the oxygen electrocatalytic layer of OIE 5, where under the influence of an electric Of potential there is an electrocatalytic process of water decomposition with the formation of oxygen at the anode and hydrogen at the cathode. Oxygen through the channels of the corrugated oxygen / air collector 3 enters the atmosphere, where it is mixed with air, and hydrogen in a mixture with undecomposed water is removed from the RTE. In all modes, air is blown through the channels of the corrugated oxygen / air collector 3 using a supercharger, and removes the heat generated during operation of the RTE.

The above description of the BRTE scheme and principle of operation confirms the industrial applicability of the claimed utility model.

Claims (1)

An open cathode regenerative fuel cell, characterized by at least two connected fuel cells, including a serially connected corrugated oxygen / air manifold 3, an oxygen / air gas diffusion layer 4, a membrane-electrode block (OIE) 5, a hydrogen gas diffusion layer 6 and a hydrogen grid collector 7 located in the frame 8, a bipolar plate 10, while the connected fuel cells of the fuel cell are installed between the end plates 1 and are separated from them okosemnymi plates 2.

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