Flash sintering of Li-ion conducting ceramic in a few seconds at 850 °C

Short sintering times and low furnace temperatures characterize the flash sintering process. The method can enable sintering of compounds of lithium since, in conventional sintering, which requires several hours at high furnace temperatures, it can become difficult to control the retention of lithium. Cubic Li6.25La3Zr2Al0.25O12 with a relative density of 96% was sintered in a few seconds in air at a furnace temperature of 850 degrees C. These specimens had an ionic conductivity of 0.5 mS cm(-1) at room temperature, and an activation energy of 0.35 eV. Transgranular nature of the fracture surface suggests strong cohesion at grain boundaries. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.