Bilayer complex proton exchange membrane and membrane electrode assembly

Abstract

A bilayer complex proton exchange membrane and a membrane electrode assembly are provided. The bilayer complex proton exchange membrane includes a first complex structure and a second complex structure. The first complex structure includes 0.001-10 wt % of a graphene derivative with two dimension configuration, and 99.999-90 wt % of organic material. The organic material includes polymer material having sulfonic acid group or phosphate group. The second complex structure includes 0.5-30 wt % of inorganic material and 99.5-70 wt % of organic material, wherein a surface area of the inorganic material is 50-3000 m.sup.2/g, and the organic material includes polymer material with sulfonic acid group or phosphate group.

Claims

1. A bilayer complex proton exchange membrane, included in a membrane electrode assembly, consists of: a first complex structure near an anode of the membrane electrode assembly, comprising: 0.001 wt % to 0.2 wt % of graphene oxide; and 99.999 wt % to 90 wt % of a first organic material that includes a PTFE-PFSA copolymer; and a second complex structure laminated to the first complex structure, and the second complex structure is near a cathode of the membrane electrode assembly, wherein the second complex structure comprises: 0.5 wt % to 30 wt % of an inorganic material, wherein a surface area of the inorganic material is 50 m.sup.2/g to 3000 m.sup.2/g; and 99.5 wt % to 70 wt % of a second organic material that includes a second polymer material with the sulfonic acid group or the phosphate group.

2. The bilayer complex proton exchange membrane of claim 1, wherein the inorganic material in the second complex structure comprises a carbon material.

3. The bilayer complex proton exchange membrane of claim 2, wherein the carbon material includes activated carbon, mesoporous carbon nanoshell, nanosheet, nanohorn, amorphous carbon or crystalline carbon.

4. A membrane electrode assembly comprising the bilayer complex proton exchange membrane of claim 3, the membrane electrode assembly comprising the anode, the bilayer complex proton exchange membrane, and the cathode.

5. A membrane electrode assembly comprising the bilayer complex proton exchange membrane of claim 2, the membrane electrode assembly comprising the anode, the bilayer complex proton exchange membrane, and the cathode.

6. The bilayer complex proton exchange membrane of claim 1, wherein the second organic material in the second complex structure comprises perfluorosulphonic acid resin, sulfonated polyether ether ketone (s-PEEK), sulfonated polyimides (s-PI), sulfonated poly (phenylene oxide) (s-PPO), sulfonated poly(arylene ether sulfone) (s-PES), or sulfonated poly (4-phenoxybenzoyl-1,4-phenylene) (s-PPBP).

7. A membrane electrode assembly comprising the bilayer complex proton exchange membrane of claim 6, the membrane electrode assembly comprising the anode, the bilayer complex proton exchange membrane, and the cathode.

8. The bilayer complex proton exchange membrane of claim 1, wherein the second organic material in the second complex structure comprises a phosphate doped polybenzimidzole polymer.

9. A membrane electrode assembly comprising the bilayer complex proton exchange membrane of claim 8, the membrane electrode assembly comprising the anode, the bilayer complex proton exchange membrane, and the cathode.

10. A membrane electrode assembly comprising the bilayer complex proton exchange membrane of claim 1, the membrane electrode assembly comprising the anode, the bilayer complex proton exchange membrane, and the cathode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings are included to provide further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments and, together with the description, serve to explain the principles of the disclosure.

(2) FIG. 1 is a schematic, cross-sectional view diagram of a bilayer complex proton exchange membrane according to a first exemplary embodiment of the disclosure.

(3) FIG. 2 is a membrane electrode assembly (MEA) according to a second exemplary embodiment of the disclosure.

(4) FIG. 3 is a diagram illustrating the comparison results in Experiment 2, in which the properties between membrane electrode assembly using the bilayer complex proton exchange membrane of example 1 and the membrane electrode assembly using the commercial proton exchange membrane NR212 are compared.

(5) FIG. 4 is a diagram illustrating the comparison results in Experiment 2, in which the properties between membrane electrode assembly using the bilayer complex proton exchange membrane of example 4 and the membrane electrode assembly using the commercial proton exchange membrane NR212 are compared.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

(6) FIG. 1 is a schematic, cross-sectional view diagram of a bilayer complex proton exchange membrane according to a first exemplary embodiment of the disclosure.

(7) Referring to FIG. 1, a bilayer complex proton exchange membrane of the first exemplary embodiment includes a first complex structure 102 and a second complex structure 104. The first complex structure 102 and the second complex structure 104 are laminated together, for example by coating, to form a film.

(8) The first complex structure includes 0.001 wt % to 10 wt % of a two-dimensional graphene derivative (2D-structure) and 99.999 wt % to 90 wt % of an organic material. The first complex structure belongs to a type of organic-inorganic hybrid complex structure. The organic material, referred hereinafter as “organic material (1)”, may include a polymer material with a sulfonic acid group or a phosphate group.

(9) The above graphene derivate includes, for example, graphene oxide, graphene sulfide, graphene hydroxide, graphene carbonate, graphene nitride or graphene sulfonate. When the graphene derivate is graphene oxide, its content in the first complex structure is between 0.001 wt % to 5 wt %, for example. When the graphene derivate is graphene sulfide, its content in the first complex structure is between 0.001 wt % to 5 wt %, for example.

(10) The organic material (1), such as a polymer material with a sulfonic acid group or a phosphate group, may include, for example, PTFE-PFSA copolymer or sulfonated hydrocarbon polymer. The sulfonated hydrocarbon polymer includes sulfonated polyether ether ketone (s-PEEK), sulfonated polyimides (s-PI), sulfonated poly (phenylene oxide) (s-PPO), sulfonated poly(arylene ether sulfone) (s-PES), or sulfonated poly (4-phenoxybenzoyl-1,4-phenylene) (s-PPBP), for example.

(11) The second complex structure includes, for example, 0.5 wt % to 30 wt % of an inorganic material and 99.5 wt % to 70 wt % of an organic material. The second complex structure is also a type of organic-inorganic hybrid complex structure, wherein the organic material, referred hereinafter as “organic material (2)”, includes a polymer material with a sulfonic acid group or a phosphate group.

(12) The surface area of the inorganic material is between about 50 m.sup.2/g to 3000 m.sup.2/g. Further, the content of the inorganic material in the second complex structure is about 0.5 wt % to about 20 wt %.

(13) The inorganic material, for example a carbon material such as activated carbon, mesoporous carbon, nanoshell, nanosheet, nanohorn, amorphous carbon or crystalline carbon, etc. It is to be understood that the above examples are presented by way of example and not by way of limitation. Any organic material, functionable as a proton exchange membrane of a micro fuel cell and has a surface area falls within the above surface area range, can be applied in the exemplary embodiment of the disclosure.

(14) The organic material (2) is a polymer material with a sulfonic acid group, such as perfluorosulphonic acid resin, sulfonated polyether ether ketone (s-PEEK), sulfonated polyimides (s-PI), sulfonated poly (phenylene oxide) (s-PPO), sulfonated poly(arylene ether sulfone) (s-PES), or sulfonated poly(4-phenoxybenzoyl-1,4-phenylene) (s-PPBP).

(15) The organic material (2) is a polymer material with a phosphate group, for example, a phosphate doped polybenzimidazole polymer.

(16) Further, if the organic material (1) and the organic material (2) are the same materials, bur also enhance the adhesion of the first complex structure 102 and the second complex structure 103.

(17) The following disclosure includes experimental results attained according to the implementation of the exemplary embodiments of the disclosure.

(18) Experiment 1

(19) Raw Materials:

(20) (1) graphene oxide aqueous solution (GO.sub.(aq))

(21) (2) inorganic water-retaining carbon material

(22) (3) Nafion dispersion: a. DE2020 solution manufactured by Dupont Company (applicable in a water/alcohol system); b. H.sup.+ Nafion DMAc dispersion (applicable in an organic solvent system).

(23) The weight percents of above GO and inorganic water-retaining carbon material are summarized in the Table 1 below.

(24) TABLE-US-00001 TABLE 1 Inorganic water-retaining carbon GO.sub.(aq) (wt %) material (wt %) Example 1 0.2  5 Example 2 0.1 10 Example 3 0.1 15 Example 4 0.1 10 (sulfonated)

(25) Physical Properties Measurements:

(26) Room temperature conductivity (rt, full RH), water volume swelling ratio, water uptake, MeOH crossover permeability are measured, and the results are summarized in Table 2 below.

(27) TABLE-US-00002 TABLE 2 NR212* Example 1 Example 2 Example 3 Example 4 Conductivity (s/cm) 0.0455 0.0455 0.050 0.041 0.052 Water Volume Swelling 66.0 43.2 51.2 56.2 47.8 Ratio (%) Water Uptake (%) 29.7 65.1 73.5 80.4 75.1 MeOH 1.57 × 10.sup.−6 1.18 × 10.sup.−6 1.34 × 10.sup.−6 6.02 × 10.sup.−7 8.28 × 10.sup.−7 Crossover Permeability (cm.sup.2/s) *NR212 is a commercial product of Nafion ®

(28) According to the results presented in Table 2, the physical properties of the bilayer complex proton exchange membranes fabricated according to examples 1 to 4 are better than those of NR212. In detail, the bilayer complex proton exchange membranes in examples 1 to 4 can block fuel crossover, with a certain degree of high water-retention capacity and lower water swelling ratio, thereby providing a longer duration of action to effectively enhance the stability of the proton exchange membrane.

(29) FIG. 2 is a membrane electrode assembly (MEA) according to a second exemplary embodiment of the disclosure. In FIG. 2, the membrane electrode assembly 200 includes an anode 202, a bilayer complex proton exchange membrane and a cathode 204. In the second embodiment, the bilayer complex proton exchange membrane, for example, the first embodiment of the bilayer complex proton exchange membrane 100 and therefore the material selection and the composition ratio can be with reference to the first embodiment. The bilayer complex proton exchange membrane has functions of inhibiting methanol crossover to the cathode, and with water retained. The anode 202 can choose to use the platinum ruthenium (PtRu) catalyst, and the cathode 204 is optionally selected to use the platinum (Pt) catalyst The anode 202 and cathode 204 are presented by way of examples and not by way of limitation.

(30) Experiment 2

(31) The bilayer complex proton exchange membrane 100 of the first exemplary embodiment with high proton conductivity, can inhibit the methanol crossover to the cathode. When the anode 202 is a platinum ruthenium (PtRu) catalyst electrode, the cathode 204 is a platinum (Pt) catalyst electrode. The membrane electrode assembly 200 can be obtained by the sequence of a anode, a bilayer complex proton exchange membrane obtained from the example 1, and a cathode by hot-pressed.

(32) Further, in the same manner to a anode, a bilayer complex proton exchange membrane obtained from the example 4, and a cathode composed another membrane electrode assembly.

(33) Under room temperature, the performance are compared with the membrane electrode assembly using the bilayer complex proton exchange membrane of example 1 and using the commercial proton exchange membrane NR212 by anode with pure methanol vapor (100% MeOH vapor) feed, and cathode with ambient air feed. The results are illustrated in FIG. 3. The fuel consumption rate and the energy efficiency are compared and the results are presented in Table 3.

(34) TABLE-US-00003 TABLE 3 Actual amount/ Theoretical Actual amount/ amount Theoretical Output Energy of methanol amount of water power efficiency MEA consumption consumption Wh % MEA NR212 1.57 −0.28 6.84 19.9 MEA 1.43 −0.25 7.38 21.7 Example 1

(35) Under room temperature, the performance are compared with the membrane electrode assembly using the bilayer complex proton exchange membrane of example 4 and using the commercial proton exchange membrane NR212 by anode with pure methanol vapor (100% MeOH vapor) feed, and cathode with ambient air feed. The results are illustrated in FIG. 4. The fuel consumption rate and the energy efficiency are compared and the results are also summarized in Table 4.

(36) TABLE-US-00004 TABLE 4 Actual amount/ Actual amount/ Theoretical Theoretical amount amount of Output Energy of methanol water power efficiency MEA consumption consumption Wh % MEA NR212 1.59 −0.27 6.31 19.4 MEA Example 4 1.50 −0.26 6.76 20.7

(37) According to the above results, the MEA with bilayer complex proton exchange membranes of example 1 and example 4 are preferred over the MEA with the commercial proton exchange membrane NR212 in micro DMFC design.

(38) In summary, the bilayer complex proton exchange membranes or MEA of the disclosure are up to the expected efficacy, and better than the commercial products.

(39) It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.