  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 601C, accompanied with increased Li+ conductivity beneficial
for battery electrolyte applications. The measured ionic conductivity is 10-3
Scm-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 mAh 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 501C. 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.
