CN111224111B

CN111224111B - Batch production device and method for fuel cell membrane electrode

Info

Publication number: CN111224111B
Application number: CN201811409571.5A
Authority: CN
Inventors: 张洪杰; 邵志刚; 郝金凯
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2018-11-23
Filing date: 2018-11-23
Publication date: 2021-04-02
Anticipated expiration: 2038-11-23
Also published as: CN111224111A

Abstract

The invention discloses a coating process and a device suitable for batch production of fuel cell membrane electrodes, wherein the device comprises the following components: the system comprises the systems of electrolyte membrane unwinding, protective film recovery, electrolyte membrane conveying, catalyst slurry dispersing and conveying, coating, tunnel heating, base membrane winding, protective film unwinding, rolling, electrolyte membrane winding and the like. The coating system is positioned on one side of the thin electrolyte membrane, and simultaneously, the preparation of catalyst layers on two sides of the electrolyte membrane is realized; the coating process is carried out on a thin electrolyte membrane supported by a base membrane, so that the wrinkling and deformation of the electrolyte membrane are effectively avoided; the protective film recycling and unreeling system can effectively protect the catalytic layer; the method realizes the drying of the catalyst layer and the hot-pressing combination of the two layers of thin electrolyte membranes by three sets of tunnel heating systems. The invention realizes the preparation of the catalyst layers at two sides of the electrolyte membrane by one-time coating, reduces the fixing times of the electrolyte membrane, avoids the damage to the electrolyte membrane and the catalyst layers and is beneficial to realizing the batch production of the membrane electrode.

Description

Batch production device and method for fuel cell membrane electrode

Technical Field

The invention relates to a method and a device suitable for batch production of fuel cell membrane electrodes, belonging to the technical field of membrane electrode batch production devices and processes.

Background

The fuel cell is an efficient and environment-friendly energy conversion device, and has wide application prospects in multiple fields of automobile transportation, distributed power generation and the like. The performance and yield of membrane electrodes, which are the core components of fuel cells, directly determine the performance and yield of fuel cell stacks and systems. At present, the fuel cell technology has already met the market lead-in period of commercial mass production, and a process technology and a device which can meet the requirements of mass production and membrane electrode preparation are urgently needed.

There are generally two methods for preparing fuel cell membrane electrodes, the GDE method and the CCM method. The GDE method is a method in which an anode catalyst layer and a cathode catalyst layer are coated on an anode gas diffusion layer and a cathode gas diffusion layer, respectively, and then an electrolyte membrane is placed between the anode catalyst layer and the cathode catalyst layer and hot-pressed to form a membrane electrode; the CCM method is to coat an anode catalyst and a cathode catalyst on both sides of an electrolyte membrane, respectively, to prepare an anode catalyst layer and a cathode catalyst layer, and then to hot-press them between two gas diffusion layers to form a membrane electrode. The two methods are the CCM method which is commonly used at present, the catalyst is directly coated on the electrolyte membrane to prepare the catalyst layer, the catalyst is better contacted with the electrolyte membrane and is beneficial to proton conduction, the utilization rate of the catalyst is higher, the consumption of Pt is reduced to a certain extent, and the performance of the battery is improved.

At present, in the CCM method for preparing the membrane electrode, the catalyst layer is mainly prepared by methods such as spraying, blade coating, screen printing and the like, and the traditional spraying device or spraying mode has limited application range and can only meet the production requirements of small area and small batch; continuous production cannot be realized by spraying, repeated steps are needed for completion, the automation degree is low, and the production efficiency is low; the process stability is relatively poor, and the consistency of the performance of different membrane electrodes in the same batch is poor.

The invention patent CN106602082A discloses a method and a device for preparing a fuel cell membrane electrode roller pair roller, which comprises an electrolyte membrane output system, an electrolyte membrane transmission system, a membrane recovery system, a catalyst slurry conveying system, at least two groups of heating systems and spray heads. The invention realizes the one-time spraying of two sides of the electrolyte membrane, realizes the simultaneous operation of two groups of heating systems and spray heads, and can realize the small-batch production of the membrane electrode.

The invention patent CN107171008A provides a membrane electrode preparation system and a preparation method. The membrane electrode preparation system comprises: the frame film preparation system is used for forming a frame film with a hollow area; the laminating system is used for respectively arranging the frame films on two sides of the proton exchange membrane and laminating to form a composite film; and the catalyst spraying system is used for spraying catalysts on the surfaces of the two sides of the composite film to form the membrane electrode.

Analysis on the preparation method of most of the current membrane electrodes, particularly CCM, shows that the method can meet the requirements of medium and small-batch production to a certain extent, but the catalyst layer is prepared in a spraying mode in the continuous production process, which invisibly limits the efficiency of the whole process; the catalyst layer prepared by the coating method has the advantages of high precision, uniform coating, suitability for coating in a larger width, convenience in realizing continuity and the like, but due to the special property of an electrolyte membrane in the membrane electrode, an anode catalyst layer and a cathode catalyst layer cannot be prepared on two sides of the electrolyte membrane simultaneously by adopting a coating mode at present.

Disclosure of Invention

In order to solve the problems in the prior art, the invention mainly provides a process method and a device suitable for roll-to-roll mass production of fuel cell membrane electrodes, and in order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a method for mass production of membrane electrodes, which comprises the following steps: respectively and simultaneously preparing a proton membrane I containing a cathode catalyst layer and a proton membrane II containing an anode catalyst layer, and then heating and pressing the proton membrane I and the proton membrane II to form CCM.

Another aspect of the present invention provides an apparatus for mass production of membrane electrodes, the apparatus mainly comprising: the two groups of electrolyte membrane unreeling systems are mainly used for unreeling electrolyte membranes, and the electrolyte membranes are thin proton exchange membranes with base membranes and protective membranes on two sides respectively; two groups of protective film recovery systems are mainly used for stripping the protective film on the surface of the electrolyte film and exposing the surface of the proton film; the electrolyte membrane transmission system is mainly used for positioning and continuously transmitting the electrolyte membrane; the two groups of catalyst slurry dispersing and conveying systems are mainly used for uniformly dispersing the catalyst slurry and continuously feeding the catalyst slurry to the coating system according to set parameters; the two groups of coating systems are mainly used for coating a catalyst layer on the surface of the proton membrane and controlling the thickness of the catalyst layer; two groups of tunnel drying systems and one group of tunnel hot-pressing systems; the tunnel drying system is used for drying the surface layer of the catalyst layer after the catalyst layer is coated, and the tunnel hot-pressing system is used for combining two layers of thin electrolyte membranes through hot pressing to form an electrolyte membrane (CCM) coated with catalyst layers on two sides of a proton membrane. Two groups of base film rolling systems are mainly used for peeling the base films of the electrolyte films to ensure that two thin proton films are in direct contact; the two groups of protective film unreeling systems are used for protecting the coated catalyst layer by utilizing the recovered protective film; the rolling system is used for realizing the pressing of the two layers of thin electrolyte films and the further fixing treatment of the protective film; the electrolyte membrane rolling system is used for rolling the CCM which finishes the coating of the catalyst layers on the two sides of the electrolyte membrane and the covering of the protective film; an electrolyte membrane conveying system for conveying an electrolyte membrane between the systems, including two sets of first systems and one set of second systems in this order along a direction in which the electrolyte membrane is conveyed; the first system is sequentially provided with a protective film recovery system, an electrolyte film unreeling system, a tunnel drying system, a base film reeling system and a protective film unreeling system along the electrolyte film conveying direction, and further comprises a coating system and a catalyst slurry dispersing and conveying system; the coating system is positioned between the electrolyte membrane unreeling system and the tunnel drying system, and the catalyst slurry dispersing and conveying system is used for uniformly dispersing the catalyst slurry and conveying the catalyst slurry to the coating system; the two groups of first systems are axially symmetrical, and the symmetrical axis is a vertical central line of the two groups of protective film unreeling systems; the two groups of protective film unwinding systems are in contact; the second system is sequentially provided with a tunnel hot-pressing system, a rolling system and an electrolyte film rolling system along the conveying direction of the electrolyte film; the electrolyte membrane is transferred between the respective systems by an electrolyte membrane transfer system.

The invention also provides a method for producing the membrane electrode in batches by using the device, which comprises the steps of respectively and simultaneously preparing a proton membrane I containing a cathode catalyst layer and a proton membrane II containing an anode catalyst layer in batches, and then heating and pressing the proton membrane I and the proton membrane II to form the membrane electrode; the method comprises the following steps in sequence: unreeling an electrolyte membrane, recovering a protective membrane, coating a catalyst layer (containing slurry for dispersion and supply), drying in an oven, peeling a base membrane and unreeling the protective membrane, hot-pressing and combining a thin proton membrane, rolling and reeling the electrolyte membrane. The method specifically comprises the following steps:

(1) respectively preparing a cathode catalyst and an anode catalyst into catalyst slurry, and conveying the catalyst slurry to two sets of catalyst slurry dispersing and conveying systems;

(2) placing an electrolyte membrane with a base membrane and a protective membrane in a coiled manner in an electrolyte membrane unreeling system (1), and peeling and drawing the protective membrane to a protective membrane recycling system; under the transmission of the electrolyte membrane transmission system, the electrolyte membrane with the protective membrane peeled off is transmitted to a coating system to be coated to form a catalyst layer; after the coating is finished, the electrolyte membrane is continuously conveyed to a tunnel drying system for drying treatment; after drying treatment, peeling the base membrane of the electrolyte membrane and drawing the base membrane to a base membrane rolling system, drawing the front end of the protective membrane on a protective membrane unwinding system to the surface of the electrolyte membrane catalyst layer, and realizing peeling of the base membrane and covering of the protective membrane on the surface of the catalyst layer under the drawing of an electrolyte membrane conveying system to obtain a proton membrane I containing a cathode catalyst layer and a proton membrane II containing an anode catalyst layer;

(3) the proton membrane I and the proton membrane II are transmitted to a tunnel hot-pressing system, and certain pressure is applied while heating, so that the proton membrane I and the proton membrane II are combined in a hot-pressing manner; and finally, further compacting and fixing the surface protective film through a rolling system to obtain the membrane electrode, and finally finishing rolling through a rolling system.

Based on the technical scheme, the coating mode is preferably slot extrusion coating, micro-concave coating or blade coating.

Based on the technical scheme, preferably, the tunnel drying system and the tunnel hot-pressing system are heated by infrared heating or contact heating, the heating temperature is 50-150 ℃, and the tunnel drying system and the tunnel hot-pressing system are heated by a preferred oven.

Based on the technical scheme, preferably, the proton membrane with the catalytic layer is combined by hot pressing, so that the anode catalyst layer and the cathode catalyst layer are simultaneously coated on two sides of the electrolyte membrane at one time, and the membrane electrode can be continuously produced in batch;

based on the technical scheme, preferably, the catalyst slurry is dispersed by a high-speed disperser or an ultrasonic dispersion mode.

Based on the technical scheme, preferably, the protective film in the protective film recycling system can be recycled.

Advantageous effects

The preparation method and the device indirectly realize the simultaneous coating and continuous production of the catalyst layers on the two sides of the proton membrane of the membrane electrode. The coating process section is equivalent to that two coating machines respectively coat one side of the proton membrane with the base membrane to prepare the catalyst layer, the proton membrane with the base membrane protection can increase the strength and the smoothness of the proton membrane, the phenomenon that the proton membrane is easy to stretch and deform or wrinkle due to low strength when two sides are coated at the same time is avoided, the influence when the first catalyst layer (cathode catalyst layer) is coated and then the second catalyst layer (anode catalyst layer) is repeatedly coated is also avoided, and the production efficiency is improved. After the catalyst layer is coated and dried, the strength of the electrolyte membrane is improved to a certain extent, the base membrane is stripped at the moment, and meanwhile, a protective film is covered on the surface of the catalyst layer, so that the catalyst layer can be effectively protected in the subsequent process, and the finished product yield of the membrane electrode is improved. The process method also has the key point that the final electrolyte membrane is formed by combining two thin proton membranes with completely same properties through heating and pressurizing, and catalyst layers are coated on two sides of the electrolyte membrane simultaneously by finally combining the two thin proton membranes into a whole so as to realize continuous and batch production of CCM.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

FIG. 1 is a schematic diagram of the apparatus of the present invention;

FIG. 2 is a flow diagram of a process of the present invention;

wherein: 1 is an electrolyte membrane unreeling system; 2 is a protective film recovery system; 3 is a catalyst slurry dispersing and conveying system; 4 is a coating system; 5 is a tunnel drying system; 6, a base film rolling system; 7, a protective film unwinding system; 8, a tunnel hot-pressing system; 9 is a rolling system; 10 is a decomposed film rolling system; and 11 is an electrolyte membrane transfer system.

Detailed Description

The coating process and apparatus of the present invention are further described below with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a membrane electrode batch production apparatus according to the present invention, which mainly includes an electrolyte membrane unwinding system 1, a protective film recovery system 2, a catalyst slurry dispersing and conveying system 3, a coating system 4, a tunnel drying system 5 (for drying a catalyst layer), a base membrane winding system 6, a protective film unwinding system 7, a tunnel hot-pressing system 8 (for hot-pressing and combining two layers of thin electrolyte membranes to form a CCM), a rolling system 9, and an electrolyte membrane winding system 10. Fig. 2 is a flow chart of a membrane electrode mass production method according to the present invention, which includes the following steps: unreeling an electrolyte membrane, recovering a protective membrane, dispersing and supplying slurry, coating a catalyst layer, drying in an oven, rolling a base membrane while applying the protective membrane, hot-pressing and combining a thin proton membrane, rolling and reeling the electrolyte membrane.

Specifically, an electrolyte membrane with a base membrane and a protective membrane is placed in an electrolyte membrane unreeling system 1 in a coiled mode, and the front end of the protective membrane is stripped from the electrolyte membrane and is pulled to a protective membrane recovery system 2; under the traction of an electrolyte membrane conveying system 11, an electrolyte membrane which is stripped from a protective film and exposes the surface of a proton membrane is conveyed to a coating system 4, catalyst slurry which is uniformly dispersed at a high speed or ultrasonically is conveyed to the coating system 4 through an injection pump, and in the coating process link, a catalyst layer is coated through one of slit extrusion, micro-concave coating or scraper coating; the electrolyte membrane with the base membrane and the catalyst layer is continuously transmitted to a tunnel oven drying system 5, and the catalyst layer is dried in an infrared heating mode; then peeling the base film of the electrolyte film and drawing the front end of the base film to a base film winding system 6, drawing the front end of the protective film on a protective film unwinding system 7 to the surface of the catalyst layer of the electrolyte film, and realizing the peeling of the base film and the covering of the protective film on the surface of the catalyst layer under the drawing of an electrolyte film conveying system 11; the inner surfaces of the two thin proton membranes are directly contacted and then are transmitted into a tunnel hot-pressing oven 8, and certain pressure is applied simultaneously in the heating process, so that the thin proton membranes are combined in a hot-pressing way; and finally, further compacting and fixing the surface protection film through a rolling system 9, and finishing rolling of the electrolyte membrane (CCM) coated with the catalyst layers on two sides of the proton membrane through a rolling system 10, so that the complete membrane electrode roll-to-roll coating production process is finished.

Example 1

The method comprises the following steps of coating slurry prepared from a carbon-supported platinum nanoparticle catalyst (Pt/C) and an isopropanol solvent on two sides of a Nafion membrane of a perfluorinated sulfonic acid membrane by the coating process method and the coating device, and preparing a membrane electrode CCM, wherein the specific steps are as follows:

1) putting a Pt/C catalyst and an isopropanol solvent into a high-speed disperser container according to a specific proportion, uniformly dispersing the Pt/C catalyst and the isopropanol solvent, and conveying the slurry to a die head (a slit extrusion device) of a coating machine through a syringe pump;

2) placing a coiled perfluorosulfonic acid film (provided with a base film and a protective film) on an output roller shaft of an electrolyte film unreeling system, drawing the protective film onto a protective film recycling roller shaft and fixing the protective film, and conveying the perfluorosulfonic acid film to a coating system under the traction of an electrolyte film conveying system to start coating;

3) after the coating of the catalyst layer is finished, the catalyst layer enters an oven drying system to be mainly dried, the organic solvent is removed, and the catalyst layer is solidified;

4) peeling the base film through a base film rolling system and a protective film rolling system, and covering a protective film on the surface of the catalyst layer;

5) the inner sides of two layers of thin perfluorosulfonic acid membranes with catalyst layers are mutually contacted, the two layers of thin perfluorosulfonic acid membranes enter a tunnel oven and are combined under the action of heating and pressurizing, and finally, the CCM is rolled through a rolling system.

Claims

1. The device for mass production of the membrane electrode is characterized by comprising two groups of first systems and one group of second systems in sequence along the conveying direction of an electrolyte membrane; the first system is sequentially provided with a protective film recovery system (2), an electrolyte film unreeling system (1), a tunnel drying system (5), a base film reeling system (6) and a protective film unreeling system (7) along the conveying direction of an electrolyte film, and further comprises a coating system (4) and a catalyst slurry dispersing and transmitting system (3); the coating system (4) is positioned between the electrolyte membrane unreeling system (1) and the tunnel drying system (5), and the catalyst slurry dispersing and conveying system (3) is used for uniformly dispersing the catalyst slurry and conveying the catalyst slurry to the coating system (4); the two groups of first systems are axially symmetrical, and the symmetrical axis is a vertical central line of the two groups of protective film unreeling systems (7); the two groups of protective film unreeling systems (7) are in contact with each other; the second system is sequentially provided with a tunnel hot-pressing system (8), a rolling system (9) and an electrolyte membrane rolling system (10) along the electrolyte membrane conveying direction; the electrolyte membrane is transferred between the respective systems by an electrolyte membrane transfer system (11).

2. A method of mass producing membrane electrodes using the apparatus of claim 1, comprising the steps of:

(1) respectively preparing a cathode catalyst and an anode catalyst into catalyst slurry, and then conveying the catalyst slurry into two sets of catalyst slurry dispersing and conveying systems (3);

(2) placing the electrolyte membrane with the base membrane and the protective membrane in a coiled manner in an electrolyte membrane unreeling system (1), and peeling and drawing the protective membrane to a protective membrane recycling system (2); the electrolyte membrane with the protective film peeled off is conveyed to a coating system (4) to be coated under the traction of the electrolyte membrane conveying system to form a catalyst layer; after the coating is finished, the electrolyte membrane is continuously conveyed to a tunnel drying system (5) for drying treatment; after drying treatment, peeling the base membrane of the electrolyte membrane and drawing the base membrane to a base membrane winding system (6), drawing the front end of the protective membrane on a protective membrane unwinding system (7) to the surface of the catalyst layer of the electrolyte membrane, and realizing the peeling of the base membrane and the covering of the protective membrane on the surface of the catalyst layer under the drawing of an electrolyte membrane conveying system to obtain a proton membrane I containing a cathode catalyst layer and a proton membrane II containing an anode catalyst layer;

(3) the proton membrane I and the proton membrane II are conveyed into a tunnel hot-pressing system (8), and certain pressure is applied while heating, so that the proton membrane I and the proton membrane II are combined in a hot-pressing manner; and finally, further compacting and fixing the surface protective film through a rolling system (9) to obtain the membrane electrode, and finally finishing rolling through a rolling system (10).

3. The method of claim 2, wherein: the coating mode is slit extrusion coating, micro-concave coating or blade coating.

4. The method according to claim 2, characterized in that the tunnel drying system (5) and tunnel hot-pressing system (8) are heated by infrared heating or contact heating; the heating temperature is 50-150 ℃.

5. The method of claim 2, wherein: the proton membrane with the catalyst layer is combined by hot pressing, so that the anode catalyst layer and the cathode catalyst layer are simultaneously coated on two sides of the electrolyte membrane at one time, and the membrane electrode can be continuously produced in batch.

6. The method of claim 2, wherein: the catalyst slurry is dispersed by a high-speed disperser or ultrasonic dispersion.

7. The method of claim 2, wherein: the protective film in the protective film recycling system (2) can be recycled.