Chung-Eun Lee

Characterizations of a new lithium ion conducting Li2O–SeO2–B2O3 glass electrolyte

Abstract A new lithium-ion conducting glass electrolyte, x Li 2 O–(1− x )(ySeO 2 –(1− y )B 2 O 3 ) was prepared by melt quenching technique and characterized using various analytical techniques. 0.5Li 2 O–0.5(ySeO 2 –(1− y )B 2 O 3 ) glass shows typical mixed-former behavior and the conductivity increased significantly compared with binary Li 2 O–B 2 O 3 glass with a maximum conductivity close to 10 −6 S/cm at y =0.5. Based on FT-IR and DSC analyses, SeO 2 acts either glass modifier or glass former as the composition of SeO 2 changes. The glass transition temperature is found to be about 300 °C, and the glass is electrochemically stable without any significant decomposition reaction between 0 and 5 V (vs. Li/Li + ).

Equal mobility of constituent cations in BaTiO3

It is widely believed that in BaTiO3, Ba2+ cations are much more mobile than Ti4+ cations. Under a dc electric field, Ba cations are therefore expected at elevated temperatures to move at a faster rate to the cathode, leading to compositional demixing and eventually to decomposition of the BaTiO3. We have found that this is not the case. Overall mass transfer in BaTiO3 does occur but with no compositional demixing. This indicates that contrary to the general belief, Ba2+ and Ti4+ have the same electrochemical mobilities in BaTiO3. This suggests a common diffusion mechanism involving both cation sublattices.