TY - JOUR
T1 - Four Phosphonium-based Ionic Liquids. Synthesis, Characterization and Electrochemical Performance as Electrolytes for Silicon Anodes
AU - Sánchez-Ramírez, Nedher
AU - Monje, Ivonne E.
AU - Martins, Vitor L.
AU - Bélanger, Daniel
AU - Camargo, Pedro H.C.
AU - Torresi, Roberto M.
N1 - Publisher Copyright:
© 2022 Wiley-VCH GmbH
PY - 2022/1/27
Y1 - 2022/1/27
N2 - Herein, we describe the synthesis, characterization and electrochemical performance of four phosphonium-based ionic liquids (ILs) as electrolytes, Physicochemical properties such as viscosity, density, ionic conductivity, and thermal stability of ILs and conventional organic solvent ethylene carbonate (EC)/diethyl carbonate (DEC) were experimentally determined at different temperatures. All ILs showed thermal stability greater than 300 °C, surpassing the stability of the conventional organic solvent, whose flash points were 145 and 23 °C for EC and DEC, respectively. Nevertheless, at room temperature, all ILs are much more viscous than EC/DEC. The composite Si -[P2224][FSI] (triethyl-n-butylphosphonium bis(fluoromethylsulfonyl)imide) and Si-EC/DEC anodes exhibit initial specific capacities at 0.15 A/g of 2409 and 2631 mAh/g, respectively. This demonstrates that despite the inferior transport properties of ILs, short alkyl-substituted phosphonium ILs like [P2224][FSI] are potentially competitive for the new generation of electrolytes for LIBs. NMR, DSC, TGA, and galvanostatic discharged/charged were used as characterization techniques.
AB - Herein, we describe the synthesis, characterization and electrochemical performance of four phosphonium-based ionic liquids (ILs) as electrolytes, Physicochemical properties such as viscosity, density, ionic conductivity, and thermal stability of ILs and conventional organic solvent ethylene carbonate (EC)/diethyl carbonate (DEC) were experimentally determined at different temperatures. All ILs showed thermal stability greater than 300 °C, surpassing the stability of the conventional organic solvent, whose flash points were 145 and 23 °C for EC and DEC, respectively. Nevertheless, at room temperature, all ILs are much more viscous than EC/DEC. The composite Si -[P2224][FSI] (triethyl-n-butylphosphonium bis(fluoromethylsulfonyl)imide) and Si-EC/DEC anodes exhibit initial specific capacities at 0.15 A/g of 2409 and 2631 mAh/g, respectively. This demonstrates that despite the inferior transport properties of ILs, short alkyl-substituted phosphonium ILs like [P2224][FSI] are potentially competitive for the new generation of electrolytes for LIBs. NMR, DSC, TGA, and galvanostatic discharged/charged were used as characterization techniques.
UR - http://www.scopus.com/inward/record.url?scp=85123802922&partnerID=8YFLogxK
U2 - 10.1002/slct.202104430
DO - 10.1002/slct.202104430
M3 - Article
AN - SCOPUS:85123802922
SN - 2365-6549
VL - 7
JO - ChemistrySelect
JF - ChemistrySelect
IS - 4
M1 - e202104430
ER -