Innovative approach for producing GDLs of PEM electrolyzers enabling a significant reduction in the manufacturing cost and facilitating higher performance than from the state of the art.
Polymer electrolyte membrane water electrolysis (PEMWE) is the most promising technology for sustainable hydrogen production. However, it has been too expensive to compete with current state-of-the-art technologies due to the...
Current collectors in PEM water electrolysis perform several functions that influence overall performance. These include conducting heat and electrons, as well as transporting water and gas. X-ray tomography, standardized reconstruction, and calculation methods are used to compare the morphological and transport parameters of eight different current collectors functioning as flow fields for PEM water electrolysis. We find simple exponential relations between through-plane thermal conductivity λ and porosity p (λ20°C(p) = 1749p−1.306 − 4.420), as well as between through-plane electrical conductivity σ and water permeability K (σ(K) = 10−6 × K−0.6376). In addition, we use both local and global concepts to investigate the pore space of current collectors. We hereby investigate homogeneity and characteristic sizes, like mean pore diameter or mean distance between solid parts at the catalytic interface. Moreover, we find that the local concept of mean chord lengths can be used to explain electrical and thermal conductivity anisotropies. These chords can be used to predict the direction of the largest conductivity for fibrous current collectors
In this work, a concept of highly efficient solar–hydrogen generation by direct coupling of III–V multijunction solar cells with proton exchange membrane (PEM) electrolysis cells is presented. III–V solar cells under concentrated illumination feature voltages above 2 V enabling the generation of hydrogen by water electrolysis. The resulting “hydrogen concentrator” is called HyCon. The temperature‐dependent electrochemical behavior of a PEM electrolysis cell is analyzed and its current–voltage characteristics are presented. The distribution of the velocity of the water flow and pressure for different flow fields is simulated by fluidic simulation. An electrolysis cell featuring a porous fiber as a current collector without any flow‐field pattern shows no visible difference in performance compared to a cell with a flow field pattern. Outdoor measurements of a HyCon module with 6 cells show a maximum efficiency of 16.8 % for one of the HyCon cells. Higher currents at lower voltages are desirable. In this respect the III–V multijunction solar cells can be optimized to obtain a higher current by adapting the indium content of each sub cell. This will lead to an increase of the system efficiency. The improvements, which will be applied in the near future, are discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.