Cold sintering and ionic conductivities of Na3.256Mg0.128Zr1.872Si2PO12 solid electrolytes

JOURNAL OF POWER SOURCES

卷:391

Article

Leng, Haoyang¹  Huang, Jiajia¹  Nie, Jiuyuan¹  Luo, Jian¹ 

[1] Univ Calif San Diego, Dept NanoEngn, Program Mat Sci & Engn, 9500 Gilman Dr, La Jolla, CA 92093 USA

关键词: Cold sintering process;    NASICON;    Ionic conductivity;    Solid-state battery;    Sodium-ion battery;   

DOI  :  10.1016/j.jpowsour.2018.04.067

来源: Elsevier

【 摘 要 】

The recent invention of cold sintering process (CSP) suggests a new opportunity to densify ceramic solid electrolytes at reduced temperatures. In the study, Na3.256Mg0.128Zr1.872Si2PO12 (Mg-doped NASICON) specimens were cold-sintered at 140 degrees C to 83% of the theoretical density. In addition, post-CSP annealing, at temperatures lower than that is needed for the conventional sintering of NASICON, can substantially increase the ionic conductivity (with or without significant further densification). For example, the conductivity of cold-sintered Mg-doped NASICON reached > 0.5 mS/cm after annealing at (as low as) 800 degrees C; in comparison, a dry-pressed specimen exhibited virtually no densification at a higher temperature of 1000 degrees C with < 0.1 mS/cm conductivity. Moreover, a high conductivity of 1.36 mS/cm has been achieved for a Mg-doped NASICON cold sintered and subsequently annealed at 1100 degrees C (doubling the conductivity of a dry-pressed specimen sintered at the identical condition). Further mechanistic studies showed that annealing at 800-1100 degrees C increased the grain boundary (GB) conductivities of cold-sintered specimens. The CSP opens a new window to sinter the thermally fragile ceramic solid electrolytes (such as phosphates and sulfates). In addition, it not only provides energy and cost savings but also enables new fabrication routes to make solid-state batteries.

【 授权许可】

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