Low temperature preparation of dense and highly conductive NASICON electrolyte by solid-state reactive sintering

NASICON-type solid-state electrolyte is characterized by high electrical conductivity but its application in allsolid-state battery is limited by the high sintering temperature and poor interface contact with the electrodes. Here, solid-state reactive sintering, without intermediate calcination and ball-milling steps and no sintering additive, is proposed to prepare dense and highly conductive NASICON at lower temperatures. The samples sintered at 950 and 1000 degrees C achieve relative density of similar to 90% and high ion conductivity of 8.43 x 10(-4) and 1.48 x 10(-3) S cm(-1) at room temperature, respectively. The reasonable interface contact between sodium metal and 950 degrees C-sintered electrolyte affords the symmetric sodium battery to cycle stably at 0.05 mA cm 2 for similar to 1000 h and full battery at 0.1C (0.02 mA cm(-2)) at room temperature. This work provides a new strategy to prepare NASICON solid-state electrolyte, which can be extended to prepare other solid-state electrolytes and thus promote the development of all-solid-state battery.

Automated summary

The NASICON-type solid-state electrolyte was prepared using solid-state reactive sintering method without sintering additives, achieving high density and ion conductivity. The reasonable interface contact between the electrolyte and sodium electrode enables stable cycling and full discharge of the symmetric sodium battery.