CN-116314979-B - Ultra-thin film electrode proton exchange membrane fuel cell and preparation method thereof

CN116314979BCN 116314979 BCN116314979 BCN 116314979BCN-116314979-B

Abstract

The invention discloses an ultrathin membrane electrode proton exchange membrane fuel cell and a preparation method thereof, wherein the ultrathin membrane electrode fuel cell has the structure that anode and cathode porous medium flow fields are arranged on two sides of an ultrathin membrane electrode, anode and cathode catalytic layers are respectively covered on the upper side and the lower side of a proton exchange membrane to form a proton exchange membrane assembly coated with the catalytic layers, the anode and the cathode catalytic layers are respectively covered by an ultrathin porous carbon fiber layer with the thickness of less than 15 mu m, and finally the ultrathin membrane electrode fuel cell is formed, wherein the total thickness of the electrode is less than 50 mu m. The preparation method comprises the steps of preparing 14% dimethylacetamide solution, carrying out electrostatic spinning, then sintering and solidifying, and then sintering at high temperature. The invention can reduce the thickness of the membrane electrode by about 90 percent and reduce the thickness of a single cell by about 41 percent. The volume power density of the fuel cell is improved by more than 100 percent. In addition, the concentration loss of the fuel cell can be effectively reduced due to the shortening of the reaction gas transmission path, so that the absolute power density of the single cell is improved by about 47%.

Inventors

JIAO KUI
ZHA SEN
WU SIYUAN

Assignees

天津大学

Dates

Publication Date: 20260512
Application Date: 20221231

Claims (3)

1. A proton exchange membrane fuel cell with an ultrathin membrane electrode is characterized in that a cathode porous medium flow field (1) and an anode porous medium flow field (3) are arranged on two sides of the ultrathin membrane electrode (2), wherein the ultrathin membrane electrode has a composition structure that a proton exchange membrane (2-3) is used as a central layer, the upper side and the lower side of the central layer are respectively covered with the cathode catalytic layer (2-2) and the anode catalytic layer (2-4) to form a proton exchange membrane assembly coated with the catalytic layers, the ultrathin porous carbon fiber layer (2-1) with the thickness of less than 10 mu m is respectively covered on the cathode catalytic layer and the anode catalytic layer, the ultrathin membrane electrode and the cathode and anode porous medium flow fields finally form the ultrathin membrane electrode of the proton exchange membrane fuel cell, and the total thickness of the ultrathin membrane electrode is less than 50 mu m.
2. The proton exchange membrane fuel cell with the ultrathin membrane electrode as claimed in claim 1, wherein the porous medium flow field is nickel metal foam with a graphene coating, the nickel metal foam grows a graphene layer on the surface of the porous medium flow field by a chemical vapor deposition method, the porosity of the nickel metal foam before compression is more than 90%, the thickness of the nickel metal foam before compression is 1.2mm to 2mm, the thickness of the nickel metal foam after compression is 250 mu m to 350 mu m, and the pore diameter is 80ppi to 110ppi.
3. A method for preparing an ultrathin membrane electrode proton exchange membrane fuel cell according to claim 1 or 2, characterized by the specific method steps of: (1) Preparing a dimethylacetamide solution with the mass fraction of 14%, placing the solution in an electrostatic spinning instrument, spinning by adopting a voltage of 10kV to 18kV and a pushing speed of 1mL per hour, and setting the rotating speed of a roller to be 20 to 200 revolutions per minute; (2) After spinning for 30min, placing the sample in a muffle furnace to sinter at 240-260 ℃ for 2 hours to solidify the sample; (3) After curing, the sample is placed in a tube furnace and sintered for 1 hour at a temperature of 1000 ℃ to 1400 ℃, the heating rate is kept below 1 ℃ per minute, the width of a receiver in the electrostatic spinning process is 10cm, and the thickness of the ultrathin porous carbon fiber layer is below 10 mu m.

Description

Ultra-thin film electrode proton exchange membrane fuel cell and preparation method thereof Technical Field The invention belongs to the field of electrochemical fuel cells, and particularly relates to an ultrathin membrane electrode proton exchange membrane fuel cell and a preparation method thereof. Background Proton Exchange Membrane Fuel Cells (PEMFCs) are a green pollution-free energy conversion device for converting hydrogen energy into electric energy, and have advantages of high energy conversion efficiency and pollution-free emission. The clean energy is being developed greatly in China, wherein hydrogen energy is considered as the clean energy in the future, and proton exchange membrane fuel cells are being developed rapidly under the promotion of government and various cart enterprises. The proton exchange membrane fuel cell applied to the automobile engine has very high requirement on the volume power density, and the main aim of each large automobile enterprise at home and abroad is to make the volume power density of the fuel cell larger. There are two routes to accomplish this, one is to make the volume of the fuel cell smaller and the other is to make the power density of the fuel cell larger. For fuel cells, the relatively large volume components are the membrane electrode and bipolar plate, and the gas diffusion layer in the membrane electrode is about 90% or more. The substrate of the gas diffusion layer used in the fuel cell so far is still carbon paper, and the bottleneck problem of the carbon paper manufacturing process technology makes it impossible to further reduce the thickness, so that the membrane electrode of the fuel cell always maintains a thickness of 250 μm or even 300 μm or more. The present invention has been made to solve the problem. Disclosure of Invention The invention aims to provide an ultrathin membrane electrode proton exchange membrane fuel cell and a preparation method thereof, which shorten the transmission of reaction gas to a catalytic layer channel and reduce the thickness of the cell at the same time so as to improve the volume power density of the fuel cell. The technical principle and the structural scheme of the invention are described as follows: The structure of the ultrathin film electrode proton exchange film fuel cell is that a cathode porous medium flow field and an anode porous medium flow field are arranged at two sides of the ultrathin film electrode. The structure of the ultra-thin film electrode is that the proton exchange film is used as a central layer, the upper and lower sides of the central layer are respectively covered with a cathode catalytic layer and an anode catalytic layer to form a proton exchange film component (CCM) coated with the catalytic layer, the cathode catalytic layer and the anode catalytic layer are respectively covered with an ultra-thin porous carbon fiber layer with the thickness of less than 15 mu m, the ultra-thin film electrode and a cathode and anode porous medium flow field are finally formed into the ultra-thin film electrode of the proton exchange film fuel cell, and the total thickness of the ultra-thin film electrode is less than 50 mu m. The preparation method of the ultrathin film electrode proton exchange membrane fuel cell comprises the following specific steps: (1) Preparing a dimethylacetamide solution with the mass fraction of 14%, placing the solution in an electrostatic spinning instrument, spinning by adopting a voltage of 10kV to 18kV and a pushing speed of 1mL per hour, and setting the rotating speed of a roller to be 20 to 200 revolutions per minute. (2) After spinning for a total period of 30min, the sample was sintered in a muffle furnace at a temperature of 240 ℃ to 260 ℃ for 2 hours to cure the sample. (3) After curing, the sample is placed in a tube furnace, sintered for 1 hour at a temperature of 1000 ℃ to 1400 ℃, the heating rate is kept below 1 ℃ per minute, the width of a receiver in the electrostatic spinning process is 10cm, and the thickness of the ultrathin porous carbon fiber layer is below 15 mu m. The ultrathin membrane electrode of the proton exchange membrane fuel cell is prepared by using an electrostatic spinning method to prepare an ultrathin porous carbon fiber membrane, and the ultrathin membrane electrode is combined with the prepared CCM to complete the ultrathin membrane electrode, and the ultrathin membrane electrode is assembled into the proton exchange membrane fuel cell or the electric pile by combining porous flow fields such as metal foam or carbon foam and the like. The invention has the characteristics that the ultrathin membrane electrode can reduce the thickness of the membrane electrode of the proton exchange membrane fuel cell by about 90 percent, and effectively improves the volume power density of the single cell by more than 100 percent. Besides, the path of the reaction gas transmitted to the catalytic layer is shortened, so that the mass transfer loss o