Densification of Ta-Doped Garnet-Type Li6.75La3Zr1.75Ta0.25O12 Solid Electrolyte Materials by Sintering in a Lithium-Rich Air Atmosphere. Issue 15 (1st January 2019)

• Record Type: Journal Article
• Authors: Zhang, Xingxing; Oh, Tae-Sik; Fergus, Jeffrey W.
• Is Part Of: Journal of the Electrochemical Society. Volume 166:Issue 15(2019)
• Page Start: A3753
• Page End: A3759
• Publication Date: 2019-01-01
• Subjects: Batteries - Lithium -- densification -- Garnet electrolytes -- ionic conductivity; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1031915jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Garnet-type Li7 La3 Zr2 O12 (LLZO) has attracted much attention because it shows promising properties for all-solid-state lithium-ion batteries. A dense microstructure is needed to obtain a high Li + conductivity, as porous microstructures result in much lower Li + conductivities. In this work, tantalum-doped cubic garnet-type Li6.75 La3 Zr1.75 Ta0.25 O12 (LLZTO) with a relative density of 92% was prepared by a simple co-precipitation method with cold uniaxial pressing and sintering in a lithium-rich air atmosphere, which was created by the addition of LiOH to the LLZTO cover powder. This LiOH-containing cover powder (15Li + LiOH) has been shown to improve densification and increase the room temperature total conductivity to 6.9 × 10 −4 S/cm with an activation energy of 0.2 eV. This 15Li + LiOH cover powder results in the formation of an Al-containing interparticle phase, which facilitates the densification of LLZTO. The aluminum concentration increases during sintering and is located in the grain boundary.