JPWO2020027728A5 - - Google Patents

Description

Figure 4 illustrates Raman spectra (400) of amorphous films and nanocrystalline graphene on _SiO2 . Raman spectroscopy of the isolated film showed no 2D peak (~2700 cm-1), but instead a broad G peak (at ~1600 cm-1) and D peak (at ~1350 cm-1). . The broadening of the D and G peaks usually indicates the transition from nanocrystalline graphene to amorphous films ^, as previously reported. From the intensity ratio of the D and G peaks, the domain size is estimated to be on the order of 1-5 nm3. Raman spectroscopy serves as a characterization tool for the large area representation of the TEM image in FIG.

The elastic modulus E of the suspended film is over 200 GPa, which is greater than bulk vitreous carbon (E=60 GPa) ⁴ . The ultimate strain before mechanical failure is 10%, which is much higher than the ultimate strains of other reported amorphous carbons. FIG. 7 shows the nanoscale at the suspended carbon film and the surface of the suspended carbon film after the ultimate stress was applied by the tip of an atomic force microscope (AFM) (eg, Bruker model number: MPP-11120). Impressions are exemplified. The amorphous nature of the disclosed 2DAC films prevents the collapse of the suspended films in FIG. 7 (bottom). Instead, the film exhibits a ductile response up to the ultimate stress level.

In selected embodiments, the disclosed 2DAC suspension films have an elastic modulus E greater than 200 GPa and a fracture energy greater than 20 J/m ² , which is more than twice the fracture energy of graphene. Evidence of the same is illustrated, for example, in FIG. In FIG. 7 , nanoindentations in the disclosed suspended 2DAC films show an elastic modulus E exceeding 200 GPa (right), and the suspended 2DAC films after the ultimate stress was applied by the AFM tip have a fracture energy of 20 J / ^m2 . Thus, these mechanical property features of the disclosed 2DAC layers increase application lifetime. For example, the disclosed barriers prevent gas penetration, thereby preventing corrosion of the electrolyte-catalyst layers. The strong mechanical properties of the disclosed 2DAC layer, in particular its high fracture toughness, ensure a long lifetime of the barriers used, thereby leading to longer overall fuel cell performance.

Claims (19)

an electrode catalyst assembly;
two-dimensional (2D) amorphous carbon ;
proton exchange membrane
wherein the 2D amorphous carbon has a crystallinity (C) of 0.8 or less ;
A fuel cell, wherein the 2D amorphous carbon is positioned between the electrocatalyst assembly and the proton exchange membrane . 2. The fuel cell of claim 1, wherein said 2D amorphous carbon is a membrane. 2. The fuel cell of claim 1, wherein said 2D amorphous carbon is a film. 2. The fuel cell of claim 1, wherein said 2D amorphous carbon has a resistivity of 0.01 to 1000 Ω-cm, inclusive. the electrode catalyst assembly comprises a plurality of electrode catalyst assemblies,
2. The method of claim 1 , wherein the proton exchange membrane is positioned between the plurality of electrocatalyst assemblies and the 2D amorphous carbon is positioned between each electrocatalyst assembly and the proton exchange membrane. A fuel cell as described. the electrode catalyst assembly comprises a plurality of electrode catalyst assemblies,
the proton exchange membrane comprises a plurality of proton exchange membranes;
2. The fuel cell of claim 1 , wherein said 2D amorphous carbon is positioned between said plurality of proton exchange membranes, and said plurality of proton exchange membranes positioned between said plurality of electrocatalyst assemblies. . 2. The fuel cell of claim 1 , wherein said proton exchange membrane is a fluoropolymer. 8. The fuel cell of claim 7 , wherein said fluoropolymer is Nafion(R). an electrode catalyst assembly;
two-dimensional (2D) amorphous carbon having an atomic structure consisting of non-hexagonal carbocycles and hexagonal carbocycles , wherein the ratio of said hexagonal carbocycles to said non-hexagonal carbocycles is less than 1.0 ,
A fuel cell, wherein the 2D amorphous carbon has a crystallinity (C) of less than 1 and an sp ³ /sp ² bond ratio of 0.2 or less. 10. The fuel cell of claim 9 , wherein said 2D amorphous carbon is a membrane. 10. The fuel cell of claim 9 , wherein said 2D amorphous carbon is a film. 10. The fuel cell of claim 9, wherein said 2D amorphous carbon has a resistivity between 0.01 and 1000 Ω-cm, inclusive. 10. The fuel cell of Claim 9 , further comprising a proton exchange membrane. 14. The fuel cell of claim 13 , wherein said 2D amorphous carbon is positioned between said electrocatalyst assembly and said proton exchange membrane. the electrode catalyst assembly comprises a plurality of electrode catalyst assemblies,
14. The method of claim 13 , wherein the proton exchange membrane is positioned between the plurality of electrocatalyst assemblies and the 2D amorphous carbon is positioned between each electrocatalyst assembly and the proton exchange membrane. A fuel cell as described. the electrode catalyst assembly comprises a plurality of electrode catalyst assemblies,
the proton exchange membrane comprises a plurality of proton exchange membranes;
14. The fuel cell of claim 13 , wherein said 2D amorphous carbon is positioned between said plurality of proton exchange membranes, and said plurality of proton exchange membranes positioned between said plurality of electrocatalyst assemblies. . 14. The fuel cell of claim 13 , wherein said proton exchange membrane is a fluoropolymer. 18. The fuel cell of claim 17 , wherein said fluoropolymer is Nafion(R). sp of the 2D amorphous carbon ³ /sp ² 2. The fuel cell according to claim 1, wherein the coupling ratio is 0.2 or less.