The electronic structure of a cathode material sets its redox chemistry, energy density, transport kinetics and structural stability, yet it is rarely discussed in conjunction with the structural design strategies that are used to improve performance. This perspective links electronic energy levels to the electrochemical properties of cathode materials. We first describe how transition-metal 3d and O 2p states, orbital hybridization, charge distribution and interfacial energy-level alignment control capacity, voltage, rate capability and cycling stability. We then re-examine four common strategies, namely elemental doping, defect engineering, composite-structure design and surface modificati... More >

Garnet-structured fluoride phosphors are attractive for phosphor-converted near-infrared light-emitting diodes (NIR pc-LEDs) owing to their broadband emission and thermal stability. Herein, pure-phase Na$_3$Al$_{2-x}$Cr$_x$Li$_3$F$_{12}$ (x = 0--0.16; NALF:Cr$^{3+}$) phosphors were synthesized hydrothermally, and their structure, morphology, crystal field, and luminescence were systematically investigated. Crystal-field analysis yielded a Dq/B of $\sim$2.18, confirming a weak crystal-field environment for Cr$^{3+}$. Under 430 nm excitation, all samples show a broad NIR band over 650--900 nm with a FWHM of $\sim$101 nm, ascribed to the $^4T_{2g}\rightarrow{}^4A_{2g}$ transition. Fluorescence... More >

Preventing pathogen transmission and treating pathogen-associated diseases remain major public-health challenges. Recent epidemics and pandemics, key amongst them being the pandemic caused by the coronavirus disease (COVID-19), have highlighted the devastating effects that viral infections can have on society. Uncovering and utilising materials for the protection from and treatment of virus-induced diseases can considerably alleviate the load imposed on healthcare systems worldwide. Silicon nitride is a biocompatible ceramic material used in orthopedic implants that is effective in the inactivation of single-stranded RNA viruses. However, the effect of the material on the more resilient DNA... More >

BaF$_2$ scintillation ceramics feature a rapid temporal response, high fast-component light yield, and a short X-ray attenuation length, making them a promising material for ultrafast X-ray imaging. In this work, BaF$_2$ nanopowder was co-precipitated from Ba(NO$_3$)$_2$ and KF$\cdot$2H$_2$O, consolidated by 600-750$^{\circ}$C air pre-sintering, and post-treated by hot isostatic pressing (HIP). The ceramics obtained under various process parameters allowed us to investigate temperature-dependent changes in microstructure, transmittance, and scintillation properties, including X-ray-excited luminescence (XEL), decay kinetics, and light yield. It was found that air pre-sintered compacts are po... More >