Research On Key Materials And Technologies Of High Specific Power Proton Exchange Membrane Fuel Cell

Compared with the existing power technologies(Li ion battery,NiMH battery,Zn ion battery,etc.),Proton exchange membrane fuel cell(PEMFC)has great advantages in safety,grid compatibility,service life,etc.However,the specific power of PEMFC is at a low level compared with the power technology mentined above.Lower specific power means that PEMFC need larger mass and volume at the same power output.Low specific power greatly limits the application scenarios of PEMFC.Therefore,we solve this problem from two aspects:increasing power density and reducing mass/volume.1)A kind of Nafion membrane with cone-shaped ordered proton conductor array was proposed and successfully prepared to meet the needs of proton conduction.The complete "three-phase interface",i.e.mass transfer,electron and proton conduction,was constructed for the first time by magnetron sputtering Loaded Pt nanoparticles and spraying loaded graphene nanosheets.After a series of optimization,the peak power density of PEMFC(H2-O2,80?)can reach 1.24 Wcm2.2)Furthermore,we propose a strategy to improve the PEMFC performance by reducing the size of the ordered proton conductor array.Through size control,the ordered proton conductor arrays with nanometer size were prepared for the first time.The ordered proton conductor array(D40)has a diameter of 40 nm and a density of 2.7×1010/cm2.The geometric specific surface area is 51.5 cm2/cm2,which is 51.5 times of the Nafion film without array.The peak power density of PEMFC(H2-O2,80?)with D40 is further increased to 1.47 Wcm-2.3)The oxygen reduction reaction on the cathode side of fuel cell is the key reaction limiting the performance of fuel cell.We have explored another "nano imprint"preparation method,which provides a solution for the preparation of bilateral arrays.The shape and size of the two-sided array can be adjusted by changing the AAO template.Bilateral ordered proton conductor arrays are expected to firther reduce the catalyst loading and improve the performance of fuel cell.4)A thin,light,highly conductive and thermally conductive difiusion layer was prepared by simple filtration on a porous graphene and carbon nanotube composite film.The thickness of the diffusion layer is only 75 ?m.Far less than the thickness of commercial carbon paper(190?m).The thickness of the diffusion layer is greatly reduced.More importantly,the sheet resistance of the diffusion layer is as low as 0.11? sq-1 is only 1/18 of the commercial carbon paper.In the self breathing PEMFC test(25?,atmospheric pressure),this diffusion layer showed a peak power density of 172.2 mW cm-2.5)In order to reduce the mass and volume of bipolar plate,we prepared an integrated,lightweight and ultra-thin plastic bipolar plate.The material of this plastic bipolar plate is polymethoxysilane(PDMS).When the flow field area sizie is 5×10 cm,the thickness of bipolar plate is only 0.7 mm and the is only 3.35 g.The bipolar plate can greatly reduce the overall mass and volume of the PEMFC.