Optimizing solid-state batteries will reduce the reliance on fossil fuel for electricity and energy storage technologies. Current energy storage technologies that are used in electric vehicles require secondary batteries with a liquid electrolyte. Safety hazards associated with the degradation of liquid electrolytes can be eliminated if a superionic conducting oxide (SCO) electrolyte were used instead. To match or exceed the current ionic conductivity values of a liquid electrolyte, SCO electrolytes need to be near theoretical density and be thermally and chemically stable in air and against metallic lithium. High-density SCO electrolytes can be produced through optimization of the sintering conditions; i.e., time, temperature, pressure, and chemical composition. Ceramic powder processing optimization of the sintering temperature and sintering mechanism has been shown here to increase the density as well as the Li-ion conductivity in the garnet-based SCO electrolyte Li7La3Zr2O12. It is reported herein that 1) increasing the sintering temperature reduced porosity, impurity phases, and the grain boundary resistance and 2) adding various amounts of a sintering aid, tri-isopropyl borate (TIB), reduced the sintering temperature and still maintained comparable electrochemical properties.
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