不同烧结条件下Li5La3Nb2O12中锂离子扩散的研究

摘要

通过介电损耗谱分析研究了不同烧结条件下锂离子导体Li5La3Nb2O12中锂离子的扩散.在介电损耗谱中观察到一个明显的弛豫峰,通过非线性拟合的方法得到了其弛豫参数,烧结温度为1 123 K的Li5La3Nb2O12样品弛豫参数:激活能E=0.54 eV,指前因子r0 =0.9×10-14s;烧结温度为1 173 K的Li5La3Nb2O12样品的弛豫参数为激活能E=0.4 eV,指前因子r0＝2.7×10-12s.后者锂离子扩散激活能小于前者,更适合于锂离子的扩散.结合晶体结构分析可得,该弛豫峰来自于锂离子在不同八面体(48 g)之间的扩散.%The lithium ion diffusion in Li5La3Nb2012 under the condition of different sintering temperature was investigated by the dielectric loss spectrum. A significant relaxation peak was observed. The relaxation parameters were obtained by non-linear fitting method. The relaxation parameters of the Li5La3Nb2012 sample under the sintering temperature of 1 123 K are E = 0. 54 eV and τ0 = 0. 9 × 10-14 s. The relaxation parameters of the Li5La3Nb2012 sample under the sintering temperature of 1 173 K are E =0.4 eV and τ0 =2.7 × 10-12 s. The lithium ion diffusion activation energy of the later sample is lower than that of the former sample. Combined with the analysis of the Li5La3Nb2012 crystalline structure,the relaxation peak is associated with the lithium ion diffusion between different octahedral sites (48 g←→48 g).