Chemical Heterogeneity in PAN/LLZTO Composite Electrolytes by Synchrotron Imaging. Issue 11 (11th November 2021)

• Record Type: Journal Article
• Authors: Xu, Tianze; Chen, Chunrun; Jin, Tianwei; Lou, Shuaifeng; Zhang, Ruiwen; Xiao, Xianghui; Huang, Xiaojing; Yang, Yuan
• Is Part Of: Journal of the Electrochemical Society. Volume 168:Issue 11(2021)
• Publication Date: 2021-11-11
• Subjects: Chemical Inhomogeneity -- Composite Electrolytes -- X-ray Fluorescence Imaging -- Transmission X-ray Microscope -- Garnet; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac352a
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Solid polymer/ceramic composite electrolytes are promising for batteries due to their attractive thermal stability and mechanical properties. Chemical heterogeneity in solid composite electrolytes, such as the inhomogeneity in the ceramic phase and salt distribution at the polymer/ceramic interface, is critical to the performance of solid composite electrolytes. However, such heterogeneity has not been well understood yet. In this work, we use Synchrotron-based X-ray fluorescence imaging (XRF) and Transmission X-ray Microscope (TXM) to image nanoscale chemical heterogeneity in polyacrylamide/Li7+x La3 Zr2−x Tax O12 (LLZTO) composite electrolytes and investigate the effects of lithium salt, salt concentration, and plasticizer. We find that LLZTO particles show strong inter- and intra-particles chemical heterogeneities, and the off-stoichiometry of Zr in an LLZTO particle is unlikely to be only balanced by Ta substitution. Moreover, statistical analysis suggests that LiI tends to accumulate at the ceramic/polymer interface at a low concentration of 5 wt%, but no such tendency was observed in samples with 10 wt% LiI. However, composite electrolytes with LiTFSI show interfacial accumulation at both 5 wt% and 10 wt%. This report provides insight into element distributions in solid composite electrolytes, and we hope further researches can shed light on the connections between chemical heterogeneity and ionic transport pathway inside.