Ionic Conductivity of β"-Alumina Solid Electrolyte Prepared by Liquid Phase Sintering Method

Na- β"-alumina solid electrolyte proposed for electric vehicle battery system application was prepared using liquid phase sintering method. Firstly, the Na- β"-alumina powder was prepared according to the formular Na1-xMg2xAl5-xO8 with x = 0.175, calcinations temperature was at 1200 C for 10 h. Calcined powder was milled and mixed with Bi2O3 or CuO in approximate concentration 1, 3 and 5 percent by mole respectively. The uniaxial dry-pressing was employed for green body forming. The green pellets were then sintered at different temperature and dwell time were kept constant for 4 h during the sintering process. Ionic conductivity measurement was performed by impedance analyzer. The XRD characterization on both powder and ceramic show that β"-alumina form as a major phase with tiny amount of the secondary phase β-alumina. The β"/β concentration proportion slightly decrease after sintering. Addition with Bi2O3 or CuO do not lead to phase change and high densification ceramic is obtained. Ionic conductivity of β"-alumina ceramic added with Bi2O3 is higher than that of ceramic with CuO addition. The relative calculated activation energy of the Na+ migration in the former composition is also lower. The highest ionic conductivity measured at 300 C is found in ceramic sample sintered at 1450 C and with 1 mol% of Bi2O3.

Download Full-text

Enhanced ionic conductivity of Na3Zr2Si2PO12 solid electrolyte with Na2SiO3 by liquid phase sintering for Na+ solid-state batteries

Nanoscale ◽

10.1039/d1nr06959d ◽

2021 ◽

Author(s):

Han Wang ◽

Genfu Zhao ◽

Shimin Wang ◽

Dangling Liu ◽

Zhi-Yuan Mei ◽

...

Keyword(s):

Solid State ◽

Liquid Phase ◽

Ionic Conductivity ◽

Solid Electrolyte ◽

Solid Electrolytes ◽

Liquid Phase Sintering ◽

High Ionic Conductivity ◽

Nasicon Type ◽

Sodium Batteries ◽

Solid State Batteries

NASICON-type Na3Zr2Si2PO12 (NZSP) is supposed to be one of the most potential solid electrolytes with the characteristics of high ionic conductivity and safety for solid-state sodium batteries. Many methods have...

Download Full-text

Sintering Behavior of the β"-Alumina Solid Electrolyte for Battery Applications

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.55-57.793 ◽

2008 ◽

Vol 55-57 ◽

pp. 793-796

Author(s):

Anuson Niyompan ◽

Kanita Srisurat ◽

Rungnapa Tipakontitikul ◽

Kamonpan Pengpat ◽

Tawee Tunkasiri

Keyword(s):

Liquid Phase ◽

Solid Electrolyte ◽

Sintering Temperature ◽

Liquid Phase Sintering ◽

Sintering Behavior ◽

Phase Identification ◽

Dry Pressing ◽

Different Temperatures ◽

Milling Method ◽

Two Phases

The β″-alumina solid electrolyte proposed for the application in the electric vehicle battery system was prepared via a liquid phase sintering method. The main aim of the study is to reduce sintering temperature which is normally required as high as 1700oC. The MgO-stabilized Naβ″-alumina with the composition Na1-xMg2xAl5-xO8 where x = 0.125 was prepared. The mixture of Na2CO3, MgO and γ -Al2O3 were produced and well-mixed by wet ball milling method. Then, calcination was performed at 1200oC for 10 h. Calcined β″-alumina was then added with a sintering aid, CuO, at several concentrations prior to forming by a dry pressing technique. The green pellets were then sintered at different temperatures with constant dwell time for 4 h. Phase identification on calcined powders indicate that β″-alumina present as a mojor phase co-existed with tiny proportion of β′-alumina. Co-existence of these two phases is commonly found for this particular system. Phase checking for sintered samples with CuO additive show no phase change but concentration ratio of the β′-alumina seem to increase with increasing sintering temperature and mol% of the CuO. Sintering at 1550oC, the higher densification is clearly observed for ceramic with higher CuO content, i.e. 5 and 10 mol%. Layered-structure of the β″-alumina can be clearly seen from the SEM micrographs. The SEM results also show that higher CuO content promoted a higher grain development and produced less porosity. Dc conductivity values of the samples with CuO adding are reasonable high comparing to that of without CuO adding. This study has been show that β″-alumina produced by liquid phase sintering here is considerably appropriate to the application in the battery of electric vehicles.

Download Full-text