Enhancement of lithium-ion conductivity for Li2.2C0.8B0.2O3 by spark plasma sintering

Abstract

Lithium-ion conductivity of Li2.2C0.8B0.2O3 pellet is 2.1 × 10-6Scm-1 at 30°C after sintering at 450°C by spark-plasma sintering (SPS) process, which is about three times higher than the conductivity of the pellet sintered at 660°C in conventional furnace. The ionic resistance at grain boundary was especially minimalized by SPS process, which would be related to the grain-growth suppression under densification as confirmed by surficial SEM image. Improvement of chargedischarge capacity could be measured at all-solid-state lithium battery assembled by the SPS process (LiCoO2Li2.2C0.8B0.2O3 composite electrolyte/Li2.2C0.8B0.2O3/dry polymer/Li foil) compared with the same compositions of the battery assembled by conventional furnace sintering, which would be due to the enhancement of the ionic transfer at LiCoO2/Li2.2C0.8B0.2O3 hetero interface as well as Li2.2C0.8B0.2O3/Li2.2C0.8B0.2O3 grain-boundary resistance.