Scientific Highlights
Bilayer Composite Membrane for the Vanadium Redox Flow Battery
The vanadium redox flow battery (VRFB) is designed for grid-scale energy storage applications. Ion-exchange membranes are performance and cost relevant components of redox flow batteries. Currently used materials are largely ‘borrowed’ from other applications that have different functional requirements. For next generation VRFBs, it would be desirable to develop membrane materials based on low-cost porous separators with low resistance and high transport selectivity to minimize vanadium-ion and electrolyte crossover.
How to increase the power density of Polymer Electrolyte Fuel Cells with evaporative cooling
A system of evaporative cooling for Polymer Electrolyte Fuel Cells (PEFCs) has been developed at PSI, based entirely on one simple, yet effective change of one of the fuel cell components. Our team at the Electrochemistry Laboratory has demonstrated how this single change allows to operate a cell without the need of bulky and costly external humidifiers. Additionally, the proposed design has the potential to increase the power density of a PEFC stack by up to 35% due to the sparing of the space usually dedicated to the convective coolant circulation.
Operando X-ray photoelectron spectroscopy, to monitor the chemical and electronic interface evolution in all-solid-state batteries
Degradation of the solid-electrolyte interface occurring during cycling is currently one of the most challenging issues for the development of all-solid-state batteries. Here we designed a unique electrochemical custom made cell for operando X-ray photoelectron spectroscopy (XPS) capable of maintaining high mechanical pressure with reliable electrochemistry and able to monitor in real-time the surface (electro-)chemical reactivity at the interfaces between the different composite.
Surface segregation acts as surface engineering for the oxygen evolution reaction on perovskite oxides in alkaline media
PSI researchers have studied the influence of surface segregation on the oxygen evolution reaction (OER) activity for the, La0.2Sr0.8CoO3-d (LSCO) perovskite, one of the most active perovskite towards the OER in alkaline electrolyte. It has been found that the higher the perovskite synthesis temperature the more strontium segregation occurs on the surface. However, the segregated strontium compounds are soluble in water and they are easily removed when the surface of the electrode is in contact with the electrolyte, leading to the exposure of cobalt enriched layers very active for the OER.
Membrane Lifetime Estimation in a Vanadium Redox Flow Battery using an Accelerated Stress Test
A vanadium redox flow battery (VRFB) is a grid-scale energy storage device. Its energy conversion unit consists of a cell stack that comprises ion-exchange membranes to separate positive and negative electrode. The projected lifetime of a VRFB is 20 years and 7’000 charge-discharge cycles. Lifetime tests of membranes under application relevant conditions are therefore impractical, and the development of an accelerated stress test (AST) to assess the chemical stability of membranes is crucial.
Hierarchically Structured Porous Transport Layers for Polymer Electrolyte Water Electrolysis
The high operational and capital costs of polymer electrolyte water electrolysis technology originate from limited catalyst utilization and the use of thick membrane electrolytes. PSI researchers have developed novel multi-layer porous transport materials, which provide superior electrochemical performance in comparison to conventional single-layer structures.
From the Walkman to the electric car
Three researchers share this year's Nobel Prize in Chemistry. They are being honoured for their respective contributions to the development of lithium-ion batteries. Petr Novák of PSI likewise works in this area of research and has known the three laureates personally for decades. In an interview, he tells about sitting directly across from one of them at the crucial moment.
Progress Towards Designed Membranes For All-Vanadium Redox Flow Batteries
Grid-scale storage of electricity is vital in energy scenarios with a high share of renewable electricity generation, such as wind and solar power. Redox flow batteries are particularly suited for intra-day time-shifting storage applications, yet investment costs need to be lowered for economic viability of the technology. We demonstrate a new ion conducting membrane that improves shortcomings of currently used materials and is potentially cheaper to produce.
Brennstoffzellen zum Durchbruch verhelfen
Wasserstoff gilt als vielversprechende Alternative für eine Zukunft ohne fossile Energieträger. Um Brennstoffzellen weiterzuentwickeln und für einen Markteintritt vorzubereiten, verstärkt die Empa die Zusammenarbeit mit der H2 Energy Holding AG und dem Paul Scherrer Institut (PSI).