Ionic Liquid-Incorporated Zn-Ion Conducting Polymer Electrolyte Membranes

Abstract

In this study, novel ionic liquid-incorporated Zn-ion conducting polymer electrolyte membranes containing polymer matrix poly (vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf), along with zinc trifluoromethanesulfonate Zn(Tf)2, are prepared and investigated. It is ascertained that the optimal membrane ILPE-Zn-4 (the mass ratio of EMITf:Zn(Tf)2:PVDF-HFP is 0.4:0.4:1), with abundant nanopores, exhibits a high amorphousness. At room temperature, the optimized electrolyte membrane offers a good value of ionic conductivity (~1.44 × 10−4 S cm−1), with a wide electrochemical stability window (~4.14 V). Moreover, the electrolyte membrane can sustain a high thermal decomposition temperature (~305 °C), and thus its mechanical performance is sufficient for practical applications. Accordingly, the ionic liquid-incorporated Zn-ion conducting polymer electrolyte could be a potential candidate for Zn-based energy storage applications.

Template-free synthesis of lignin-derived 3D hierarchical porous carbon for supercapacitors

“…At low frequencies, the vertical lines parallel to the imaginary axis are clearly observed for LHPC, indicating a quasi-ideal capacitive behavior and low diffusion resistance. The low diffusion resistance of LHPC is ascribed to its high macropore and mesopores volumes that increase the pore accessibility for the electrolyte ions [40,41]. On the contrary, the Nyquist plot of LPC is obviously deflected to the real axis at low frequencies, reflecting the poor diffusion ability of electrolyte ions in its microporous structure.…”

Materials and Structure Design for Solid-State Zinc-Ion Batteries: A Mini-Review

“…For example, a PEGDGE/ Zn(CF 3 SO 3 ) 2 SSE using a PC plasticizer addressed evaporation and obtained an ionic conductivity of 0.377 mS cm −1 while maintaining constant surface resistance for over 200 h (Dong et al, 2020). The latest research implements ionic liquids in place of traditional plasticizers, increasing the quantity of ions within the electrolyte (Liu et al, 2020a;Ma L et al, 2020). The addition of these ionic liquids increased the ionic conductivity of polymer electrolytes, widened the electrochemical stability window resolving HER reactions, and provided nonflammability, low volatility, and high thermal and chemical stabilities (Liu et al, 2020a;Ma L et al, 2020;Francis et al, 2020).…”

“…The latest research implements ionic liquids in place of traditional plasticizers, increasing the quantity of ions within the electrolyte (Liu et al, 2020a;Ma L et al, 2020). The addition of these ionic liquids increased the ionic conductivity of polymer electrolytes, widened the electrochemical stability window resolving HER reactions, and provided nonflammability, low volatility, and high thermal and chemical stabilities (Liu et al, 2020a;Ma L et al, 2020;Francis et al, 2020). One example uses 1-ethyl-3methyl-imidazolium tetrafluoroborate ([EMIM]BF 4 ) and zinc tetrafluoroborate [Zn(BF 4 ) 2 ] salt to form an ILZE electrolyte that reportedly solved both HER side reactions and Zn dendrite issues inherent to ZIBs (Ma L et al, 2020).…”

“…This electrolyte was also much thinner and stronger (5 orders of magnitude stronger modulus) than other GPEs. Using trifluoromethanesulfonate (EMITf), PvDF-HFP and Zn(CF 3 SO 3 ) 2 delivered an ionic conductivity of 0.144 mS cm −1 , widened the electrochemical stability window (∼4.14 V), and provided excellent thermal stability up to 305°C (Liu et al, 2020a). These ionic liquids have been found to improve both PVdF-HFP and PEO/PVdF copolymer electrolytes (Tafur et al, 2015;Rathika and Suthanthiraraj, 2018;Zhang Y et al, 2020).…”

Ionic Conductive Polymers for Electrochemical Devices

“…In addition, the rigid hyperbranched structure showed an enhancement of the swelling ratio and demonstrated an alkaline stability under 2M KOH conditions over 1000h at 50 • C. Jienkulsawad et al [4] employed, in the fabrication of membrane electrode assemblies (MEAs), a PVA to humidify the membrane in proton-exchange membrane fuel cells (PEMFCs) operated under low-humidity conditions. The 0.03 wt% PVA in the anode catalyst layer (CL) and 0.1 wt% PVA on the gas diffusion layer (GDL) improve the current density by approximately 30% at the operating voltage of 0.6 V and non-humidified anode and cathode humidifier temperature of 25 • C. Liu et al [5] prepared a novel membrane containing a polymer matrix poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf), along with zinc trifluoromethanesulfonate Zn(Tf) 2 . The best amorphous and nanopored membrane, ILPE-Zn-4, with a mass ratio of 0.4:0.4:1 (EMITf:Zn(Tf) 2 :PVDF-HF), showed at room-temperature (RT) ionic conductivity of ~1.44 × 10 −4 S cm −1 with a wide electrochemical stability window (~4.14 V) and thermal decomposition temperature ~305 • C with good tensile strength ~5.7 MPa.…”