We investigate oxygen redox in layered Na2−xMn3O7, a positive electrode material with ordered Mn vacancies. Our results establish a complete picture of redox energetics by highlighting the role of coulombic interactions across several atomic distances and suggest avenues to stabilize highly oxidized oxygen for applications in energy storage and beyond. Read more »
David Prendergast Wins 2021 Shirley Award
David Prendergast, an internationally recognized computational scientist whose first-principles calculations of x-ray spectra have helped with the interpretation of countless experiments done at the ALS, has been awarded the 2021 Shirley Award for Outstanding Scientific Achievement by the ALS Users’ Executive Committee. Read more »
X-Ray Study Recasts Role of Battery Material from Cathode to Catalyst
Researchers used the ALS to learn about a lithium-rich battery material that has been the subject of much study for its potential to extend the range of electric vehicles and the operation of electronic devices. Through a fundamental spectroscopic study, they not only clarified the reaction mechanism of this material, but also found a conceptually different use of it as a catalyst. Read more »
Study Shines New Light on Li-Battery Cathode Materials
Researchers clarified key reaction mechanisms in a Li-battery cathode material, revealing its surprising utility as a catalyst for next-gen batteries. The work refutes widely held ideas about reversible reactions in a highly debated material for Li-based batteries and expands the range of materials suitable for use in high-power batteries and fuel cells. Read more »
Redirecting dynamic surface restructuring of a layered transition metal oxide catalyst for superior water oxidation
Electrocatalysts, particularly those for water oxidation, often experience substantial or at least partial reconstruction. Here, Wang et al. are able to control surface reconstruction using a cationic redox-tuning method on layered LiCoO2–xClx catalysts for the oxygen evolution reaction. The resulting optimized catalyst exhibits excellent electrocatalytic performance in alkaline electrolyte. Read more »
Speeding Toward Improved Hydrogen Fuel Production
Researchers synthesized a material that speeds up one of the limiting steps in extracting hydrogen from alcohols. The catalyst cleanly and efficiently accelerates the removal of hydrogen atoms from a liquid chemical carrier. The material is robust, made from earth-abundant metals, and will help make hydrogen a viable energy source for a wide range of applications. Read more »
Detecting Phonon Overtones in Correlated Materials
Resonant inelastic x-ray scattering (RIXS) has recently been shown to be a promising technique for studying electron–phonon coupling in correlated materials. When a photoexcited electron interacts with phonons during decay, it shows up in the RIXS spectra as clear phonon overtones: higher-order excitations that appear as ripples in intensity. Read more »
Reversible Room-Temperature Fluoride-Ion Insertion in a Tunnel-Structured Transition Metal Oxide Host
Fluoride ions show promise as charge carriers in batteries but have limited cyclability. Here we show the reversible and homogeneous topochemical insertion/deinsertion and bulk diffusion of F ions within the one-dimensional tunnels of submicrometer-sized FeSb2O4 particles at room temperature. Read more »
2020 Shirley Award to Honor Miquel Salmeron
By taking surface studies from ultrahigh vacuum to near-ambient pressure, Miquel Salmeron’s work at the ALS has had deep impact on a broad range of scientific questions, revealing the chemical, electronic, and mechanical properties of surfaces and interfaces on the nanometer (and often atomic) scale. Read more »
Seeing ‘Under the Hood’ in Batteries
To push battery performance, researchers want to learn how the individual ingredients of battery materials behave beneath the surface. But many techniques only scratch the surface of what’s at work inside batteries. A high-sensitivity x-ray technique is attracting a growing group of scientists because it provides a deeper, more precise dive into battery chemistry. Read more »