TY - JOUR
T1 - Understanding fluorine-free electrolytes via small-angle X-ray scattering
AU - Qian, Kun
AU - Yu, Zhou
AU - Liu, Yuzi
AU - Gosztola, David J.
AU - Winans, Randall E.
AU - Cheng, Lei
AU - Li, Tao
N1 - Publisher Copyright:
© 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences
PY - 2022/7
Y1 - 2022/7
N2 - Fluorine-free electrolytes have attracted great attention because of its low-cost and environmental friendliness. However, so far, little is known about the solution structures of these electrolytes. Here, we compare the solvation phenomenon of sodium tetraphenylborate (NaBPh4) salt dissolved in organic solvents of propylene carbonate (PC), 1,2-dimethoxyethane (DME), acetonitrile (ACN) and tetrahydrofuran (THF). Small-angle X-ray scattering (SAXS) reveals a unique two-peak structural feature in this salt-concentrated PC electrolyte, while solutions using other solvents only have one scattering peak. Molecular dynamics (MD) simulations further reveal that there are anion-based clusters in addition to the short-range charge ordering in the concentrated NaBPh4/PC electrolyte. Raman spectroscopy confirms the existence of considerable contact ion pairs (CIPs). This work emphasizes the importance of global and local structural analysis, which will provide valuable clues for understanding the structure-performance relationship of electrolytes.
AB - Fluorine-free electrolytes have attracted great attention because of its low-cost and environmental friendliness. However, so far, little is known about the solution structures of these electrolytes. Here, we compare the solvation phenomenon of sodium tetraphenylborate (NaBPh4) salt dissolved in organic solvents of propylene carbonate (PC), 1,2-dimethoxyethane (DME), acetonitrile (ACN) and tetrahydrofuran (THF). Small-angle X-ray scattering (SAXS) reveals a unique two-peak structural feature in this salt-concentrated PC electrolyte, while solutions using other solvents only have one scattering peak. Molecular dynamics (MD) simulations further reveal that there are anion-based clusters in addition to the short-range charge ordering in the concentrated NaBPh4/PC electrolyte. Raman spectroscopy confirms the existence of considerable contact ion pairs (CIPs). This work emphasizes the importance of global and local structural analysis, which will provide valuable clues for understanding the structure-performance relationship of electrolytes.
KW - Fluorine-free electrolytes
KW - Small-angle X-ray scattering
KW - Sodium tetraphenylborate
KW - Sodium-ion batteries
KW - Solvation structures
UR - http://www.scopus.com/inward/record.url?scp=85127033902&partnerID=8YFLogxK
U2 - 10.1016/j.jechem.2022.02.043
DO - 10.1016/j.jechem.2022.02.043
M3 - Article
AN - SCOPUS:85127033902
SN - 2095-4956
VL - 70
SP - 340
EP - 346
JO - Journal of Energy Chemistry
JF - Journal of Energy Chemistry
ER -