No Evidence of Benefits of Host Nano-Carbon Materials for Practical Lithium Anode-Free Cells.

Nano-carbon-based materials are widely reported as lithium host materials in lithium metal batteries (LMBs); however, researchers report contradictory claims as to where the lithium plating occurs. Herein, the use of pure hollow core-carbon spheres coated on Cu (PHCCSs@Cu) to study the lithium deposition behavior with respect to this type of structure in lithium anode-free cells is described. It is demonstrated that the lithium showed some initial and limited intercalation into the PHCCSs and then plated on the external carbon walls and the top surface of the carbon coating during the charging process. The unfavorable deposition of lithium inside the PHCCSs is discussed from the viewpoint of lithium-ion transport and lithium nucleation. The application potential of PHCCSs and the data from these LMB studies are also discussed.

Highly crystalline ramsdellite as a cathode material for near-neutral aqueous MnO2/Zn batteries.

Chemically-prepared MnO2 containing a highly crystalline ramsdellite phase was tested as a cathode material in aqueous Zn-salt (ZnSO4 and Zn(CF3SO3)2) based electrolytes for the first time. This aqueous MnO2/Zn cell has shown excellent performance and reversibility, retaining ≈65% of its initial capacity for more than 1000 cycles. The charge storage mechanism is complex and includes a ramsdellite/tetragonal spinel two-phase reaction.

Electroanalytical Sensing of Bromides Using Radiolytically Synthesized Silver Nanoparticle Electrocatalysts.

Monitoring bromides (Br-) is of crucial importance since bromates, potential human carcinogens, are formed during ozonation of water containing bromides in concentrations >100 µg L-1. Within this study, silver (Ag) and four carbon-supported Ag catalysts were synthesized by the γ-radiation method and their morphology and structure examined using transmission electron microscopy, X-ray diffraction, and UV-Vis analysis. The nanocatalysts were tested for Br- sensing in aqueous media using cyclic voltammetry. All five Ag materials exhibited electroactivity for sensing of Br- ions, with pure Ag catalyst giving the best response to Br- ions presence in terms of the lowest limit of detection. Sensing of bromides was also explored in tap water after addition of bromides suggesting that herein prepared catalysts could be used for bromides detection in real samples. Furthermore, sensing of other halogen ions, namely, chlorides and iodides, was examined, and response due to chloride presence was recorded.