摘要
以Al_2O_3、ZrO_2、Nb_2O_5、MoO_3和(NH_4)_2HPO_4为原料,采用高温固相法合成了Al^(3+)导电固体电解质(Al_(0.2)Zr_(0.8))_((4-x)/3.8)NbP_(3-x)Mo_xO_(12)(0.0≤x≤0.2)。利用X射线衍射技术(XRD)、场发射扫描电子显微镜(SEM)、电化学交流阻抗测试技术(EIS)对样品的相组成、微观形貌和电化学性能进行表征。结果表明:不同Mo^(6+)掺杂比例的固体电解质(Al_(0.2)Zr_(0.8))_((4-x)/3.8)NbP_(3-x)Mo_xO_(12)(x=0.00、0.05、0.10、0.15、0.20)均具有三维NASICON型结构,Mo^(6+)的引入并未改变固体电解质的晶体结构。与未掺杂的铝离子固体电解质(Al_(0.2)Zr_(0.8))_(20/19)Nb(PO_4)_3相比,掺杂不同比例Mo^(6+)所得固体电解质基片的晶粒大小更加均匀,晶粒连接更加紧密,致密性增强,当掺杂比例x=0.15时,致密性最高,在500℃的测试温度下,(Al_(0.2)Zr_(0.8))_(3.85/3.8)NbP_(2.85)Mo_(0.15)O_(12)的离子电导率最高,为1.30×10^(-3)S·cm^(-1),约为相同温度下(Al_(0.2)Zr_(0.8))_(20/19)Nb(PO_4)_3的4倍。通过直流极化法测得其离子迁移数均在0.99以上,表明固体电解质(Al_(0.2)Zr_(0.8))_(3.85/3.8)NbP_(2.85)Mo_(0.15)O_(12)中主要是Al^(3+)传导,电子传导可忽略不计。
Different compositions of NASICON-type (Al0.2Zr0.8)(4-x)3.8NbP3-xMoxO12(0.0≤x≤0.2) were successfully synthesized by the high-temperature solid state reaction route with aluminum oxide, zirconium oxide, niobium oxide, molybdenum oxide and ammonium dibasic phosphate as raw materials. The phase composition, crystal structure and electrical properties were also investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The results indicate that the (Al0.2Zr0.8)(4-x)3.8NbP3-xMoxO12 series consist of a three-dimensional network structure of the NASICON-type structure. The dopant had not changed the crystal patterns. Compared with the undoped solid electrolyte of (Al0.2Zr0.8)20/19Nb(PO4)3, the grains were regularized in size and shape and distributed uniformly, which demonstrated that the compactness was enhanced and reached the strongest when the doping content of Mo6+ is 0.15(Al0.2Zr0.8)3.85/3.8NbP2.85Mo0.15O12 (x=0.15) possesses the highest conductivity of 1.30×10-3 S·cm-1 at 500℃ increasing approximately four times than (Al0.2Zr0.8)20/19Nb(PO4)3. The ion transference number measured by the method of DC polarization was higher than 0.99 indicating the fact that the predominant conducting species in (Al0.2Zr0.8)3.85/3.8NbP2.85Mo0.15O12 is Al3+ cation and the electron conduction is negligible.
出处
《陶瓷学报》
北大核心
2017年第3期342-345,共4页
Journal of Ceramics
基金
国家自然科学基金(51472073)