Preparation of monophasic titanium sub-oxides of Magneli phase with enhanced thermoelectric performance
Preparation of monophasic titanium sub-oxides of Magneli phase with enhanced thermoelectric performance
复制标题
具有增强热电性能的Magneli相单相钛低氧化物的制备
DOI：
10.1016/j.jeurceramsoc.2017.09.040
复制
发表时间：
2018-02-01
影响因子：
5.7
通讯作者：
Kawasaki, Akira
中科院分区：
文献类型：
--
作者：
Fan, Yuchi;Feng, Xiaopeng;Kawasaki, Akira
mageli相的钛亚氧化物被认为是一种储量丰富的、无毒的高温热电材料，但由于单相材料难以获得，对其的研究非常有限。本文介绍了一种制备单相Ti9O17和Ti4O7粉末的简便策略，其中首次获得了Ti9O17的单相。对比研究了放电等离子烧结后单相Ti9O17和Ti4O7陶瓷的热电性能。尽管电导率低一个数量级，但由于塞贝克系数大，Ti9O17的功率因数比Ti4O7高。此外，由于Ti9O17具有较低的电子热导率、亚微米级的晶粒尺寸和纳米级的晶体剪切面，与Ti4O7相比，Ti9O17的热导率更低，在764 K时的ZT为0.16，是所报道的Magneli相中热电性能最好的。
Titanium sub-oxides of Magneli phase are considered as earth-abundant, non-toxic materials for thermoelectric application at high temperature, but very limited investigation has been reported mainly owing to the difficulty lying in obtaining monophasic material. Herein we describe a facile strategy to prepare monophasic Ti9O17 and Ti4O7 powder, in which the single Ti9O17 phase is obtained for the first time. After spark plasma sintering, the thermoelectric properties of monophasic Ti9O17 and Ti4O7 ceramics are studied comparatively. Despite the one magnitude lower electrical conductivity, Ti9O17 shows higher power factor compared with Ti4O7 due to the large Seebeck coefficient. Moreover, with the low electronic thermal conductivity, sub-micron scaled grain size and nano-scaled crystallographic shear plane, the Ti9O17 ceramic exhibits even lower thermal conductivity compared to Ti4O7, leading to a ZT of 0.16 at 764 K, which is the best thermoelectric performance among reported Magneli phases.