Abstract
The increasing demand for a safe rechargeable battery with a high energy density per cell is driving a search for a novel solid electrolyte with a high Li+ or Na+ conductivity that is chemically stable in a working Li-ion or Na-ion battery. Li6ZnNb4O14 has been reported to exhibit a Li > 10-2 S cm-1 at 250C, but to disproportionate into multiple phases on cooling from 850C to room temperature. An investigation of the room-temperature Li-ion conductivity in a porous pellet of a multiphase product of a nominal Li6ZnNb4O14 composition is shown to have bulk Li 3.3 x 10-5 S cm-1 at room temperature that increases to 1.4 x 10-4 S cm-1 by 50C. 7Li MAS NMR spectra were fitted to two Lorentzian lines, one of which showed a dramatic increase with increasing temperature. A test for water stability indicates that Li+ may move to the particle and grain surfaces to react with adsorbed water as occurs in the garnet Li+ conductors.
