Ultrahigh ionic conductivity in optimally sintered Li10.35Ge1.35P1.65S12 superionic conductor
Lithium superionic conductor Li10+δGe1+δP2−δS12 has attracted tremendous interest for advanced all-solid-state lithium ion batteries due to extremely high ionic conductivity. However, the synthetic processes reported in literature are widely divergent, resulting in an order of magnitude difference in ionic conductivities of the same material, but as far as we know, the influence of synthetic conditions on ionic conductivity has not been studied yet. Herein, we systematically investigate the influence of sintering temperature on phase composition and ionic conductivity of the Li10+δGe1+δP2−δS12 compounds synthesized by conventional solid-state reaction for the first time. It is found that low and high sintering temperatures lead to a low crystallinity and the formation of impurity phases, respectively. As a result, the pure Li10.35Ge1.35P1.65S12, well crystallized in space group P42/nmc, is fabricated by optimization of the solid-state reaction temperature at 580 °C and its room temperature conductivity (19 mS cm− 1) is the highest among all existing Li10+δGe1+δP2−δS12 solid electrolytes. Meanwhile, the microstructure of Li10.35Ge1.35P1.65S12, being very dense and uniform, is demonstrated firstly by atomic force microscopy.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Posted 21 Sep, 2020
Ultrahigh ionic conductivity in optimally sintered Li10.35Ge1.35P1.65S12 superionic conductor
Posted 21 Sep, 2020
Lithium superionic conductor Li10+δGe1+δP2−δS12 has attracted tremendous interest for advanced all-solid-state lithium ion batteries due to extremely high ionic conductivity. However, the synthetic processes reported in literature are widely divergent, resulting in an order of magnitude difference in ionic conductivities of the same material, but as far as we know, the influence of synthetic conditions on ionic conductivity has not been studied yet. Herein, we systematically investigate the influence of sintering temperature on phase composition and ionic conductivity of the Li10+δGe1+δP2−δS12 compounds synthesized by conventional solid-state reaction for the first time. It is found that low and high sintering temperatures lead to a low crystallinity and the formation of impurity phases, respectively. As a result, the pure Li10.35Ge1.35P1.65S12, well crystallized in space group P42/nmc, is fabricated by optimization of the solid-state reaction temperature at 580 °C and its room temperature conductivity (19 mS cm− 1) is the highest among all existing Li10+δGe1+δP2−δS12 solid electrolytes. Meanwhile, the microstructure of Li10.35Ge1.35P1.65S12, being very dense and uniform, is demonstrated firstly by atomic force microscopy.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5