Elucidation of the Co state with strong charge-transfer effects in charged LiCoO by resonant soft X-ray emission spectroscopy at the Co L edge.

To understand the electronic-structure change of LiCoO, a widely used cathode material in Li-ion batteries, during charge-discharge, we performed soft X-ray absorption spectroscopy (XAS) and resonant soft X-ray emission spectroscopy (RXES) of the Co L edge in combination with charge-transfer multiplet calculations. The RXES profile significantly changed for the charged state at 4.2 V Li/Li, corresponding to the oxidation reaction from a Co low-spin state for the initial state, while the XAS profile exhibited small changes.

Electronic structures of blue copper centers of amicyanin and azurin in the solution state.

X-ray absorption near edge structure (XANES) spectra of blue copper proteins, amicyanin and azurin, in the solution state were measured in the copper L-edge energy region. The absorption peak energies were quite similar for both proteins, while the main edge region for azurin was broader than that for amicyanin, owing to more pronounced shoulder spectral features in the former. calculations at the whole protein level qualitatively reproduced the experimental spectra well.

Synergistic Impact of Alloying with Ni on Cu Cathode Interfaces for Fluoride Batteries.

All-solid-state fluoride batteries have the potential to achieve energy densities significantly higher than those of lithium-ion batteries. A common cathode material for fluoride batteries is Cu. Cu has a low polarization, but its rapid capacity degradation due to grain growth and subsequent delamination from the solid-state electrolyte are critical issues.