Scientific Highlights
Cross-Talk–Suppressing Electrolyte Additive for Li-ion Batteries
Control of interfacial reactivity at high-voltage is a key to high-energy-density Li-ion batteries. 2-aminoethyldiphenyl borate was investigated as an electrolyte additive to stabilize surface and bulk of both NCM851005 and graphite in the cell with upper cut-off voltage of 4.4 V vs Li+/Li. AEDB almost completely eliminated the “cross-talk” in the cell, by significantly reducing metal leaching from the cathode, preventing their deposition at the anode, and further electrolyte decomposition.
Excellent cycling stability of graphite in all-solid-state battery using sulfide solid electrolyte
All-solid-state lithium ion batteries represent a promising battery technology for boosting the volumetric energy density and promising a superior safety. In this study excellent cycling stability of graphite anode material have been demonstrated in combination with sulfide-based solid electrolyte. Furthermore we evaluated the stability of the graphite-electrolyte interface by analyzing the normalized cumulative irreversible charge during cycling experiments.
Impact of micro-porous layers (MPL) on two-phase flow in electrolyzers
Polymer Electrolyte Water Electrolyzers (PEWE), due to their excellent dynamic characteristics, can provide an economical solution to the intermittent nature of new renewable sources, by converting the excess electricity into hydrogen. However, improvements in efficiency and in capital cost are still required for the large-scale deployment of this solution. In this context, we studied whether the efficiency improvements observed when using porous structures featuring a micro-porous layer (MPL) can be attributed to a better distribution of the water.
Using X-ray emission spectroscopy to study the electronic properties of single atom catalysts
Single atom catalysts hold great promise as O2- or CO2-reduction electrocatalysts, but a deeper understanding of their active sites’ structure and electronic properties is needed in order to render them sufficiently active and stable. To this end, we have used X-ray emission spectroscopy to determine these catalysts’ electronic configuration, and performed in situ measurements that unveil the effect of potential on this key feature.
Temperature Dependent Water Transport Mechanism
Subsecond and submicron operando X-ray tomographic microscopy (XTM) was applied to reveal the water dynamics inside the gas diffusion layer (GDL) of polymer electrolyte fuel cells (PEFC). Utilizing the instrumental advancements in operando XTM of PEFCs the contribution of capillary-fingering and phase-change-induced flow on water transport in GDLs was quantified, for the first time during fuel cell startup at different operation temperatures.
Efficient Water Electrolysis at Elevated Temperature using Commercial Cell Components
Decarbonization of the energy system across different sectors using power-to-X concepts relies heavily on the availability of low-cost hydrogen produced from renewable power by water electrolysis. Polymer electrolyte water electrolysis (PEWE) is a promising technology for hydrogen (and oxygen) production for distributed as a well as centralized operation. The total cost of hydrogen is dominated by the electricity cost. Therefore, increase of conversion efficiency is pivotal in improving the commercial viability of electrolytically produced hydrogen. In this study, we investigate the prospects of improving conversion efficiency by reducing the membrane thickness from 200 to 50 micron and increasing the cell temperature from 60 to 120°C.
Graphite Anodes with Si as Capacity-Enhancing Electrode Additive
Silicon is a long-standing candidate for replacing graphite as the active material in negative electrodes for Li-ion batteries, due to its significantly higher specific capacity. However, Si suffers from rapid capacity loss, as a result of the large volume expansion and contraction during lithation and de-lithiation. As an alternative to pure Si electrodes, Si could be used as a capacity-enhancing additive to graphite electrodes.
Oxygen Evolution Reaction Activity and Underlying Mechanism of Perovskite Electrocatalysts at Different pH
PSI researchers have studied the how the electrolyte pH values influence the oxygen evolution reaction (OER) activity and stability of different promising perovskite oxide catalysts for application as anodic electrodes in alkaline water electrolyzers. The OER activity and stability decreased decreasing the electrolyte pH values. By combining electrochemical studies and operando X-ray absorption spectroscopy measurements, it has been suggested that different reaction mechanisms dominate in alkaline and near-neutral electrolyte pH region.
Analysis of cation contamination of polymer electrolyte water electrolysers (PEWEs)
With the help of in situ PEWE regeneration methods, we can potentially enable the treatment of degraded cells without the necessity of stack disassembly, saving operation costs of the plant. In this context, we observed the movement of cations in a PEWE cell using neutron imaging and compared it with a model. This model is expected to be useful for the early detection of cation contamination problems in PEWEs, and the monitoring of in situ regeneration.