Spatially resolved structural order in low-temperature liquid electrolyte

YJ Xie and JY Wang and BH Savitzky and Z Chen and Y Wang and S Betzler and K Bustillo and K Persson and Y Cui and LW Wang and C Ophus and P Ercius and HM Zheng, SCIENCE ADVANCES, 9, eadc9721 (2023).

DOI: 10.1126/sciadv.adc9721

Determining the degree and the spatial extent of structural order in liquids is a grand challenge. Here, we are able to resolve the structural order in a model organic electrolyte of 1 M lithium hexafluorophosphate (LiPF6) dissolved in 1:1 (v/v) ethylene carbonate:diethylcarbonate by developing an integrated method of liquid- phase transmission electron microscopy (TEM), cryo-TEM operated at -30 degrees C, four-dimensional scanning TEM, and data analysis based on deep learning. This study reveals the presence of short-range order (SRO) in the high-salt concentration domains of the liquid electrolyte from liquid phase separation at the low temperature. Molecular dynamics simulations suggest the SRO originates from the Li+-(PF6-)(n) (n > 2) local structural order induced by high LiPF6 salt concentration.

Return to Publications page