柠檬酸盐溶胶-凝胶法合成LiZn(P_(1-x)V_x)O_4及其离子导电性

LiZn(P_(1-x)V_x)O_4 Synthesised by a Citrate Sol-Gel Method and Its Ionic Conductivity

采用柠檬酸盐溶胶 -凝胶法合成了组成为 Li Zn(P1- x Vx) O4 (x=0 ,0 .1 ,0 .2 ,0 .3,0 .4,0 .5)的离子导体 ,并对合成材料进行了差示热分析 (DTA)、热重分析 (TG)、X射线衍射 (XRD)和透射电镜 (TEM)等表征。实验结果表明 ,组成为 Li Zn PO4 的烧结体结构为 α- L i Zn PO4 ;x=0 .4,0 .5的烧结体具有 Li Zn VO4 结构 ,为固溶体 (Li Zn VO4 )单相 ;而 x=0 .1 ,0 .2 ,0 .3的烧结体是由 α- Li Zn PO4 和 Li Zn VO4 两相组成的。由于 α- Li Zn PO4 烧结体的相对密度极小 ,样品在室温下几乎不显示导电性 ;而掺杂了 V以后的样品 ,随着结构和组成不同显示出不同程度的导电性 ,其中以 x=0 .4时值最大 ,T=30℃时 σ=4.55× 1 0 - 7S· cm- 1。

The ion conductors, LiZn(P 1-x V x )O 4( x =0, 0 1, 0 2, 0 3, 0 4, 0 5), were synthesised by a citrate sol gel method, and have been studied using thermogravimetric analysis(TG), differential thermal analysis(DTA), SEM, XRD and ac impedance(ac IP). The results indicate that the solid solution, LiZn(P 1- y V y )O 4, 0 5≤ y ≤0 6, has the LiZnVO 4 structure. However, LiZn(P 1-x V x )O 4( x =0 1,0 2,0 3) is a mixture of α LiZnPO 4 and LiZnVO 4 phases. The structure of the sintered LiZnPO 4 is α phase. The conductivities of doped LiZn(P 1- x V x )O 4 are much higher than that of undoped LiZnPO 4, its maximum value being 4 55×10 -7 s·cm -1 for x =0 4 at 30℃.