Pseudo-ternary LiBH4·LiCl·P2S5 system as structurally disordered bulk electrolyte for all-solid-state lithium batteries.

The properties of the mixed system LiBH4-LiCl-P2S5 are studied with respect to all-solid-state batteries. The studied material undergoes an amorphization upon heating above 60 °C, accompanied with increased Li+ conductivity beneficial for battery electrolyte applications. The measured ionic conductivity is ∼10-3 S cm-1 at room temperature with an activation energy of 0.40(2) eV after amorphization. Structural analysis and characterization of the material suggest that BH4 groups and PS4 may belong to the same molecular structure, where Cl ions interplay to accommodate the structural unit. Thanks to its conductivity, ductility and electrochemical stability (up to 5 V, Au vs. Li+/Li), this new electrolyte is successfully tested in battery cells operated with a cathode material (layered TiS2, theo. capacity 239 mA h g-1) and Li anode resulting in 93% capacity retention (10 cycles) and notable cycling stability under the current density ∼12 mA g-1 (0.05C-rate) at 50 °C. Further advanced characterisation by means of operando synchrotron X-ray diffraction in transmission mode contributes explicitly to a better understanding of the (de)lithiation processes of solid-state battery electrodes operated at moderate temperatures.

MgH2-CoO: a conversion-type composite electrode for LiBH4-based all-solid-state lithium ion batteries.

Several studies have demonstrated that MgH2 is a promising conversion-type anode toward Li. A major obstacle is the reversible capacity during cycling. Electrochemical co-existence of a mixed metal hydride-oxide conversion type anode is demonstrated for lithium ion batteries using a solid-state electrolyte. 75MgH2·25CoO anodes are obtained from optimized mixing conditions avoiding reactions occurring during high-energy ball-milling. Electrochemical tests are carried out to investigate the cycling capability and reversibility of the on-going conversion reactions. The cycling led to formation of a single-plateau nanocomposite electrode with higher reversibility yield, lowered discharge-charge hysteresis and mitigated kinetic effect at high C-rate compared to MgH2 anodes. It is believed that reduced diffusion pathways and less polarized electrodes are the origin of the improved properties. The designed composite-electrode shows good preservation and suitability with LiBH4 solid electrolyte as revealed from electron microscopy analyses and X-ray photoelectron spectroscopy.

Tritium labeling of detonation nanodiamonds.

For the first time, the radioactive labeling of detonation nanodiamonds was efficiently achieved using a tritium microwave plasma. According to our measurements, the total radioactivity reaches 9120 ± 120 µCi mg(-1), with 93% of (3)H atoms tightly bonded to the surface and up to 7% embedded into the diamond core. Such (3)H doping will ensure highly stable radiolabeled nanodiamonds, on which surface functionalization is still allowed. This breakthrough opens the way to biodistribution and pharmacokinetics studies of nanodiamonds, while this approach can be scalable to easily treat bulk quantities of nanodiamonds at low cost.