Page 176 - 《精细化工》2020年第9期

第 37 卷第 9 期 精 细 化 工 Vol.37, No.9
202 0 年 9 月 FINE CHEMICALS Sept. 2020

有机电化学与工业
冷烧结工艺制备石榴石固态电解质及其性能

张 颖，杨 迪，张军战，刘安栋

（西安建筑科技大学 材料科学与工程学院，陕西 西安 710055）

摘要：以 LiNO 3 、Al(NO 3 ) 3 •9H 2 O、La(NO 3 ) 3 •6H 2 O、ZrO(NO 3 ) 2 •5H 2 O 为原料，采用溶胶-凝胶法制备了
Li 5.95 Al 0.35 La 3 Zr 2 O 12 粉体，随后加入聚乙烯醇（PVA）水溶液作为液相介质，通过冷烧结工艺制备了
Li 5.95 Al 0.35 La 3 Zr 2 O 12 石榴石固态电解质。冷烧结工艺后采用后续热处理改善离子传导性能。采用质量体积法和电
化学阻抗谱对 Li 5.95 Al 0.35 La 3 Zr 2 O 12 石榴石固态电解质的体积密度和离子电导率进行了测试，采用 XRD 与 SEM
进行晶体结构与形貌表征。结果表明，冷烧结时间和压力对样品的晶体结构几乎没有影响。冷烧结时间过长会
导致样品开裂，在 15~30 min 时，冷烧结时间对样品的体积密度和离子电导率影响不大，在烧结时间较短的样
品中发现了杂相。提高冷烧结压力可明显提高样品的体积密度和离子电导率，在 200 ℃、510 MPa、30 min 的
–6
冷烧结条件下可以获得具有较高离子电导率（2.66×10 S/cm）的 Li 5.95 Al 0.35 La 3 Zr 2 O 12 石榴石固态电解质，其晶
界电阻较小。但继续增加冷烧结压力，导致热处理过程中第二相的分解和晶粒生长受到抑制，样品的体积密度
和离子电导率反而下降。
关键词：冷烧结工艺；石榴石固态电解质；离子电导率；热处理；体积密度；有机电化学与工业
中图分类号：TM911.3 文献标识码：A 文章编号：1003-5214 (2020) 09-1890-06

Preparation and properties of garnet solid-state electrolyte
via cold sintering process

ZHANG Ying, YANG Di, ZHANG Junzhan, LIU Andong
（College of Materials Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055,
Shaanxi, China）

Abstract: Li 5.95Al 0.35La 3Zr 2O 12 powder was prepared by sol-gel method with LiNO 3, Al(NO 3) 3 •9H 2O,
La(NO 3) 3 •6H 2O and ZrO(NO 3) 2 •5H 2O as raw materials. Then polyvinyl alcohol (PVA) aqueous solution
was added as liquid medium to prepare Li 5.95Al 0.35La 3Zr 2O 12 garnet solid electrolyte via cold sintering
process. Finally, subsequent heat treatment was employed to improve its ionic conduction properties. The
volume density and ionic conductivity of Li 5.95Al 0.35La 3Zr 2O 12 garnet solid-state electrolyte were tested by
mass volume method and electrochemical impedance spectroscopy (EIS). The crystal structure and
morphology were characterized by XRD and SEM, respectively. The results showed that cold sintering
holding time and pressure had little effect on the crystal structure of the samples. Too long cold sintering
time would lead to cracking of the sample. The cold sintering time had little effect on the volume density
and ionic conductivity of the samples within 15 to 30 min. But impurities were detected in the sample with
short sintering time. It was found that increasing the cold sintering pressure could improve the volume
density and ionic conductivity. Li 5.95Al 0.35La 3Zr 2O 12 garnet solid electrolyte with higher ionic conductivity
–6
of 2.66×10 S/cm could be obtained at 510 MPa, 200 ℃ and 30 min, and its grain boundary resistance was
lower. However, with the further increase of cold sintering pressure, the volume density and ionic
conductivity of the sample decreased due to the decomposition of second phase and the inhibition of grain
growth during heat treatment.

收稿日期：2020-03-16; 定用日期：2020-05-13; DOI: 10.13550/j.jxhg.20200204
基金项目：国防科技重点实验室基金（Z20180467）
作者简介：张 颖（1972—），女，副教授，E-mail：xayzhang@xauat.edu.cn。