Polymer electrolytes (PE) represent the ultimate in terms of desirable properties for the next-generation of safe and efficient energy storage and conversion devices. They promise an all-solid-state construction, a wide variety of shapes and sizes, lightweight, low-cost of fabrication, high safety and a high energy density. In this communication, we present a summary of our recent results, regarding the synthesis, physical-chemical and electrochemical characterization of PE membranes based on different monomers/oligomers (methacrylic and/or ethylene oxide based) with several kinds of additives, salts, plasticizers and fillers. In addition, room temperature ionic liquids (RTIL) are incorporated into the membranes to improve safety. The crosslinking produced by UV irradiation allows the incorporation of high amount of RTIL (imidazolium, pyrrolidinium etc.) and/or tetraethylene glycol dimethyl ether (tetraglyme) with lithium salt (based on TFSI- anion), withstanding remarkable homogeneity and robustness. Tensile analysis confirmed that the membranes exhibit improved Young’s modulus even with >50 wt.% of RTIL. Thermal stability up to 375°C under inert conditions is achieved and X-ray diffraction analysis (XRD) confirmed the role of photo curing step in reducing the overall crystallinity of the samples. Excellent ionic conductivity (> 5x10–4 S cm–1 at 25 °C), wide electrochemical stability (>5V vs. Li+/Li), and excellent interfacial stability towards lithium are also envisaged. The ability to resist the lithium dendrite nucleation and growth was tested by galvanostatic polarization studies. Lab-scale Li-polymer cell were assembled, which showed stable charge/discharge characteristics without any capacity fading (>140 mAh g-1) at various current rates with LiFePO4 and/or TiO2 working electrodes. The PE membrane after some modifications were tested in dye-sensitized solar cells (DSSCs). The introduction of iodine/iodide-based redox mediator in the polymer matrix assured the functioning of a lab-scale test cell with conversion efficiency exceeding 6% at 1 sun. The overall results achieved on such systems demonstrate that, compared to other techniques, UV curing is a versatile method, easy to be scaled-up at an industrial level due to its easiness and rapidity in processing. It can open up promising perspectives in obtaining innovative electrolytes with high flexibility, well suited for flexible and/or non-planar electronics application.

Novel polymer electrolyte membranes for energy storage and conversion systems / Nair, JIJEESH RAVI; Bella, Federico; Porcarelli, Luca; Colo', Francesca; Meligrana, Giuseppina; Gerbaldi, Claudio. - ELETTRONICO. - (2015). (Intervento presentato al convegno 3rd Indo-Italian Workshop on Electrochemistry for Energy & Health tenutosi a Delhi (India) nel July 2nd and 3rd, 2015).

Novel polymer electrolyte membranes for energy storage and conversion systems

NAIR, JIJEESH RAVI;BELLA, FEDERICO;PORCARELLI, LUCA;COLO', FRANCESCA;MELIGRANA, Giuseppina;GERBALDI, CLAUDIO
2015

Abstract

Polymer electrolytes (PE) represent the ultimate in terms of desirable properties for the next-generation of safe and efficient energy storage and conversion devices. They promise an all-solid-state construction, a wide variety of shapes and sizes, lightweight, low-cost of fabrication, high safety and a high energy density. In this communication, we present a summary of our recent results, regarding the synthesis, physical-chemical and electrochemical characterization of PE membranes based on different monomers/oligomers (methacrylic and/or ethylene oxide based) with several kinds of additives, salts, plasticizers and fillers. In addition, room temperature ionic liquids (RTIL) are incorporated into the membranes to improve safety. The crosslinking produced by UV irradiation allows the incorporation of high amount of RTIL (imidazolium, pyrrolidinium etc.) and/or tetraethylene glycol dimethyl ether (tetraglyme) with lithium salt (based on TFSI- anion), withstanding remarkable homogeneity and robustness. Tensile analysis confirmed that the membranes exhibit improved Young’s modulus even with >50 wt.% of RTIL. Thermal stability up to 375°C under inert conditions is achieved and X-ray diffraction analysis (XRD) confirmed the role of photo curing step in reducing the overall crystallinity of the samples. Excellent ionic conductivity (> 5x10–4 S cm–1 at 25 °C), wide electrochemical stability (>5V vs. Li+/Li), and excellent interfacial stability towards lithium are also envisaged. The ability to resist the lithium dendrite nucleation and growth was tested by galvanostatic polarization studies. Lab-scale Li-polymer cell were assembled, which showed stable charge/discharge characteristics without any capacity fading (>140 mAh g-1) at various current rates with LiFePO4 and/or TiO2 working electrodes. The PE membrane after some modifications were tested in dye-sensitized solar cells (DSSCs). The introduction of iodine/iodide-based redox mediator in the polymer matrix assured the functioning of a lab-scale test cell with conversion efficiency exceeding 6% at 1 sun. The overall results achieved on such systems demonstrate that, compared to other techniques, UV curing is a versatile method, easy to be scaled-up at an industrial level due to its easiness and rapidity in processing. It can open up promising perspectives in obtaining innovative electrolytes with high flexibility, well suited for flexible and/or non-planar electronics application.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2615892
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo