The PSI Electrochemistry Laboratory studies almost all aspects of electrochemical energy storage and conversion.
Lab News & Scientific Highlights
Best practices for harnessing operando X-ray absorption spectroscopy in electrocatalytic water splitting studies
X-ray absorption spectroscopy (XAS) has found applications in a range of fields including materials, physics, chemistry, biology and earth science. XAS can probe the local electronic and geometric structure, such as the average oxidation state, coordination environment and interatomic distances, surrounding an element of interest. Thus, XAS is a valuable tool to inform catalyst design by tracking catalyst evolution under operating conditions, for example, via providing dynamic snapshots of the essential information.
Hydrogen Electrode for Membrane Water Electrolyzers with Low Gas Crossover
Proton exchange membrane (PEM) water electrolyzer are considered a for the Energy Transition to produce green hydrogen for fuel cell-based mobility, industrial processes, and seasonal storage. Platinum group metals (PGMs) are conventionally used as catalysts for electrode reactions due to their outstanding catalytic activity and chemical stability in the harsh acidic environment of the cell. Commercial carbon-supported platinum (Pt/C) electrocatalysts remains a state-of-the-art choice for the hydrogen evolution reaction (HER) on the cathode side of the cell. While a high Pt loading between 0.5 and 1.0 mgPt/cm2 is commonly used today, a reduction of the Pt loading to below 0.05 mgPt/cm2 is desired to reduce the cost of PGM usage in megawatt-scale PEM water electrolysis systems. In addition, in connection with the trend towards the use of thinner membranes (<0.1 mm), gas crossover through the membrane from the cathode to the anode side can lead to the formation of an explosive gas mixture in the anode product stream. In this study, we varied the design parameters for the cathode catalyst layer to reduce the Pt loading to 0.025 mg/cm2 while at the same time minimizing the rate of hydrogen crossover to the anode.
Real-Time Insights into Sodium-Ion Battery Chemistry
Identification of gaseous decomposition products from irreversible side-reactions enables understanding of inner working of rechargeable batteries. Unlike for Li-ion batteries, the knowledge of the gas-evolution processes in Na-ion batteries is limited. Our study revealed that Na-ion cells develop a less stable solid-electrolyte interphase (SEI) compared to Li-ion cells due to higher solubility of SEI constituents in Na-electrolytes.