@article {1065, title = {Initial approaches in benchmarking and round robin testing for proton exchange membrane water electrolyzers}, journal = {International Journal of Hydrogen Energy}, volume = {44}, year = {2019}, month = {04/2019}, pages = {9174-9187}, abstract = {

Published on April 5th, 2019. As ever-increasing amounts of renewable electricity enter the energy supply mix on a regional, national and international basis, greater emphasis is being placed on energy conversion and storage technologies to deal with the oscillations, excess and lack of electricity. Hydrogen generation via proton exchange membrane water electrolysis (PEMWE) is one technology that offers a pathway to store large amounts of electricity in the form of hydrogen. The challenges to widespread adoption of PEM water electrolyzers lie in their high capital and operating costs which both need to be reduced through R\&D. An evaluation of reported PEMWE performance data in the literature reveals that there are excessive variations of in situ performance results that make it difficult to draw conclusions on the pathway forward to performance optimization and future R\&D directions. To enable the meaningful comparison of in situ performance evaluation across laboratories there is an obvious need for standardization of materials and testing protocols. Herein, we address this need by reporting the results of a round robin test effort conducted at the laboratories of five contributors to the IEA Electrolysis Annex 30. For this effort a method and equipment framework were first developed and then verified with respect to its feasibility for measuring water electrolysis performance accurately across the various laboratories. The effort utilized identical sets of test articles, materials, and test cells, and employed a set of shared test protocols. It further defined a minimum skeleton of requirements for the test station equipment. The maximum observed deviation between laboratories at 1\ A\ cm-2 at cell temperatures of 60\ {\textdegree}C and 80\ {\textdegree}C was 27 and 20\ mV, respectively. The deviation of the results from laboratory to laboratory was 2{\textendash}3 times higher than the lowest deviation observed at one single lab and test station. However, the highest deviations observed were one-tenth of those extracted by a literature survey on similar material sets. The work endorses the urgent need to identify one or more reference sets of materials in addition to the method and equipment framework introduced here, to enable accurate comparison of results across the entire community. The results further imply that cell temperature control appears to be the most significant source of deviation between results, and that care must be taken with respect to break-in conditions and cell electrical connections for meaningful performance data.

}, issn = {0360-3199}, doi = {10.1016/j.ijhydene.2019.02.074}, url = {http://www.sciencedirect.com/science/article/pii/S0360319919306585}, author = {G. Bender and M. Carmo and T. Smolinka and A. Gago and N. Danilovic and M. Mueller and F. Ganci and A. Fallisch and P. Lettenmeier and K. A. Friedrich and K. Ayers and B. Pivovar and J. Mergel and D. Stolten} } @article {1020, title = {Durable Membrane Electrode Assemblies for Proton Exchange Membrane Electrolyzer Systems Operating at High Current Densities}, journal = {Electrochimica Acta}, volume = {210}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {502-511}, abstract = {High efficiencies, wide operation range and rapid response time have motivated the recent interest in proton exchange membrane (PEM) electrolysis for hydrogen generation with surplus electricity. However, degradation at high current densities and the associated mechanism has not been thoroughly explored so far. In this work, membrane electrode assemblies (MEA) from different suppliers are aged in a commercial PEM electrolyzer (2.5Nm3H2h--1), operating up to 4Acm--2 for more than 750h. In all cases, the cell voltage (Ecell) decreases during the testing period. Interestingly, the cells with Ir-black anodes exhibit the highest performance with the lowest precious metal loading (1mgcm-2). Electrochemical impedance spectroscopy (EIS) shows a progressive decrease in the specific exchange current, while the ohmic resistance decreases when doubling the nominal current density. This effect translates into an enhancement of cell efficiency at high current densities. However, Ir concurrently leaches out and diffuses into the membrane. No decrease in membrane thickness is observed at the end of the tests. High current densities do not lead to lowering the performance of the PEM electrolyzer over time, although MEA components degrade, in particular the anode.}, issn = {0013-4686}, doi = {10.1016/j.electacta.2016.04.164}, url = {http://www.sciencedirect.com/science/article/pii/S0013468616310167}, author = {P. Lettenmeier and R. Wang and R. Abouatallah and S. Helmly and T. Morawietz and R. Hiesgen and S. Kolb and F. Burggraf and J. Kallo and A. S. Gago and K. A. Friedrich} } @article {1010, title = {Low-Cost and Durable Bipolar Plates for Proton Exchange Membrane Electrolyzers}, journal = {Scientific Reports}, volume = {7}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {44035}, abstract = {Cost reduction and high efficiency are the mayor challenges for sustainable H2 production via proton exchange membrane (PEM) electrolysis. Titanium-based components such as bipolar plates (BPP) have the largest contribution to the capital cost. This work proposes the use of stainless steel BPPs coated with Nb and Ti by magnetron sputtering physical vapor deposition (PVD) and vacuum plasma spraying (VPS), respectively. The physical properties of the coatings are thoroughly characterized by scanning electron, atomic force microscopies (SEM, AFM); and X-ray diffraction, photoelectron spectroscopies (XRD, XPS). The Ti coating (50 μm) protects the stainless steel substrate against corrosion, while a 50-fold thinner layer of Nb decreases the contact resistance by almost one order of magnitude. The Nb/Ti-coated stainless steel bipolar BPPs endure the harsh environment of the anode for more than 1000 h of operation under nominal conditions, showing a potential use in PEM electrolyzers for large-scale H2 production from renewables.}, issn = {2045-2322}, doi = {10.1038/srep44035}, url = {https://www.nature.com/articles/srep44035}, author = {P. Lettenmeier and R. Wang and R. Abouatallah and B. Saruhan and O. Freitag and P. Gazdzicki and T. Morawietz and R. Hiesgen and A. S. Gago and K. A. Friedrich} }