Na_(3.3)Zr_(1.65-x)Ti_(x)Si_(1.9)P_(1.1)O_(11.5)系统钠快离子导体的合成及性能研究

The Preparation and Properties of NaZrTiSiPO(11.5) System

具有三维离子通道的骨架结构的钠快离子导体NASICON(Na_(1+x)Zr_(2)Si_(x)P_(3-x)O_(12),0≤x≤3)固溶体系的研究,揭示了在1.8≤x≤2.4的组成范围内合成物的导电性最好(δ573.2K=S·m^(-1)。因此被认为可应用于高温Na/S电池。然而该电池的初步研究表明NASICON对液钠是不稳定的,这种不稳定被认为是由于研究的样品NASICON中总含有ZrO_(2)杂质。为此人们曾为制备纯的NASICON单相作了不少的探索。

Sodium fast ion conductors Na_(3.3)Zr_(1.65-x)Ti_(x)Si_(1.9)P_(1.1)O_(11.5) were prepared from mixtures of Na_(3)PO_(4),ZrP_(2)O_(7)-ZrO_(2)-TiO_(2)-SiO_(2) in platinum vessel at temperatures of 1173.2-1473.2K for several hours to 20 hand 40 h. Most of reactions were carried out at the temperature range 1373.2-1423.2 K. The phases, of NASICON plus ZrO_(2) were found, in the composition range x = 0-0.4. A pure NASlCON phase was found with x = 0.5-0.9. A galss state appeared in x>0.9. Theoretical densities were evaluated according to the cell parameters determined. Electrical conductivities were measured from room temperature to 673.2K. In the same phase range, the conductivity always decreases with increasing x. The best conductor is Na_(3.3) Zr1.05 Ti0.6 Si1.1 P1.1 O11.5 with conductivity . 47.2(S·m^(-1)) ,at 673.2 K. The activation energy data show that most compositions of Na_(3.3)Zr_(1.65-x)TixSi_(1.9)P_(1.1)O_(11.5) system are good conductors.