Lithium amide–borohydrides Li[BH₄]_1–x[NH₂]_x possess liquid-like Li superionic conductivity at nearly ambient temperature. The fast Li⁺ diffusion facilitated by the localized motions of the anions is proposed to occur through a network of vacant tetrahedral sites, acting as conduction channels. To study the reorientational dynamics of the anions, we have performed quasielastic neutron scattering experiments on samples with different compositions (x = 2/3, 0.722, 0.737, 3/4) over a broad temperature and time range. To unambiguously disentangle the contributions of the two species, [BH₄]^− and [NH₂]^−, we took advantage of deuterium labeling and could clearly demonstrate that the quasielastic broadening is mainly determined by the [BH₄]^− reorientations. With the help of a newly developed model, supported by ab initio molecular dynamics calculations, we have identified three relaxation components, which account for generally anisotropic C₃-rotations of the [BH₄]^− tetrahedra including jumps by a small angle from the equilibrium position.

High ionic conductivity of up to 6.4 ×10^−3S cm^−1 near room temperature  (40 °C) in lithium amide-borohydrides is reported, comparable to values  of liquid organic electrolytes commonly employed in lithium-ion batteries.  Density functional theory is applied coupled with X-ray diffraction, calorimetry, and nuclear magnetic resonance experiments to shed light on the  conduction mechanism. A Li₄Ti₅O₁₂ half-cell battery incorporating the lithium amide-borohydride electrolyte exhibits good rate performance up to 3.5 mA cm^−2 (5 C) and stable cycling over 400 cycles at 1 C at 40 °C, indicating high bulk and interfacial stability. The results demonstrate the potential of lithium amide-borohydrides as solid-state electrolytes for high-power lithium-ion batteries.

Electron spin resonance of a high-T_c Bi superconductor sample is reported. The d.c. susceptibility, d.c. resistivity and a.c. susceptibility show two superconducting transitions at 105 K and 75 K. The ESR spectra show a main resonance line whose temperature dependence is studied in detail. The g value shows a maximum of 2.24 at 230 K and decreases to 2.12 at 100 K. The line width also shows a maximum of 520 G at the same temperature and drops to 200 G at 100 K. An unusual behaviour is observed in the decrease of the integrated intensity from a maximum at 230 K to below noise at level 100 K. It is possible that the origin of this signal is due to impurity phases. However, the unusual behaviour of its intensity (disappearance of the signal below T_c) may indicate that it arises from pair formation much above T_c.