High rate and long-term cycling of silicon anodes with phosphonium-based ionic liquids as electrolytes for lithium-ion batteries

Author(s)

Sanchez-Ramirez, Nedher ; Monje, Ivonne E. ; Belanger, Daniel ; Camargo, Pedro H. C. ; Torresi, Roberto M.

• Document type: Journal article
• Source: Electrochimica Acta; v. 439, p. 8-pg., 2022-12-10.

Abstract

This paper describes the effects of the length of the phosphonium alkyl chain in FSI-based ionic liquids (ILs) used as an electrolyte solvent with Si electrodes in a Li/Si half-cell. The electrochemical performance of Si nano-particles at a high rate in the synthesized triethyl-n-butylphosphonium bis(fluorosulfonyl)imide) [P-2224][FSI] and triethyl-n-octylphosphonium bis(fluorosulfonyl)imide) [P-2228][FSI] ILs, which also contain 1 M LiFSI, is compared with that of a common organic electrolyte using either polyacrylic acid (PAA) or polyacrylonitrile (PAN) as a binder. For the three electrolytes, the highest performance was obtained with the PAN binder, while both electrodes in ILs exhibited superior performance compared to the conventional organic electrolyte. For the Si/PAN composite electrode, after 1000 cycles at 1 A.g(-1), the delithiation capacities were 1344, 550 and 136 mAh.g(-1) for [P-2224][FSI] in 1 M LiFSI, [P-2228][FSI] in 1 M LiFSI and the commercial organic electrolyte, which corresponded to capacity retentions of 61%, 50% and 5%, respectively. Our results indicate that the chemical structure of the phosphonium cation enabled the tuning of transport properties and significantly influences the electrochemical behavior of the Si anode in the presence of LiFSI/IL as an electrolyte. (AU)

• FAPESP's process: 14/01987-6 - Study of lithium intercalation into different nanostructured cathode based on oxides of transition metal using ionic liquid (ILs) with low viscosity synthesized from phosphonium and tetracyanoborate like electrolytes.
• Grantee: Nédher Sánches Ramírez
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/20043-7 - Nanoparticles for the formation of porous silicon and as conductive additives for anode in Lithium Ion Batteries
• Grantee: Ivonne Eliana Monje López
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/07638-7 - Surface modification of cathodes for lithium ion batteries: electrode/electrolyte interface studies
• Grantee: Ivonne Eliana Monje López
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 15/26308-7 - Optimization of the physicochemical properties of nano -structured materials for applications in molecular recognition, catalysis and energy conversion/storage
• Grantee: Roberto Manuel Torresi
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 20/08553-2 - Computational spectroscopy of diatomic molecules
• Grantee: Antonio Gustavo Sampaio de Oliveira Filho
• Support Opportunities: Regular Research Grants
• FAPESP's process: 21/00675-4 - Tying up materials for electrochemical energy storage and catalysis
• Grantee: Roberto Manuel Torresi
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/11164-0 - Study of lithiation of silicon nanopowder produced by induced plasma using ionic liquids as electrolytes
• Grantee: Nédher Sánches Ramírez
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor