Ionic Liquid-Based Electrolytes for Advanced Electrochemical Energy Conversion and Storage Systems – an Overview
Authors: Di Noto Vito , Vezzù Keti , Negro Enrico , Pagot Gioele 
Published: December 2024

The global transition currently underway towards green electrification necessitates advanced energy conversion and storage solutions to harness, distribute and use effectively the energy obtained from renewable sources. Secondary batteries, which can exploit a variety of chemistries (e.g., based on Li, Na, Mg and others), offer promising avenues but face challenges involving a high cost and environmental concerns. Ionic liquid (IL)-based electrolytes are a compelling solution, grounded in their customizable chemistry and ensuring a high performance and durability [1, 2].
This work presents an overview of IL-based electrolytes for secondary batteries. The specific topics taken under consideration cover the synthesis of the IL-based electrolytes, their characterization and their implementation in electrochemical energy conversion and storage (EECS) devices [3, 4]. Various synthetic approaches are discussed, yielding IL-based electrolytes tailored for specific applications. Such IL-based electrolytes exhibit desirable properties such as chemistry modulation of mobile species, facile ion transport, and a wide electrochemical stability window. The complex interplay between synthetic parameters, physicochemical properties, and performance is elucidated in detail. Several different families of IL-based electrolytes are presented, focusing in particular on systems incorporating δ-metal halide salts [5] and discussing in detail how the latter affect the thermal stability, the vibrational features, and the electrochemical properties of the IL-based electrolyte.
Through this research, we aim to contribute to the advancement of IL-based electrolytes as a key component in the realization of high-performance and durable batteries running on lithium and other metals, with the ultimate goal to foster the global transition towards sustainable energy solutions.

References

[1] F. Bertasi, C. Hettige, F. Sepehr, X. Bogle, G. Pagot, K. Vezzù, E. Negro, S. J. Paddison, S. G. Greenbaum, M. Vittadello, V. Di Noto, ChemSusChem 8 (2015) 3069-3076.
[2] F. Bertasi, G. Pagot, K. Vezzù, A. Nale, G. Pace, Y. Herve Bang, G. Crivellaro, E. Negro, V. Di Noto, Electrochim. Acta 307 (2019) 51-63.
[3] F. Bertasi, F. Sepehr, G. Pagot, S. J. Paddison, V. Di Noto, Adv. Funct. Mater. 26 (2016) 4860-4865.
[4] G. Pagot, K. Vezzù, S. G. Greenbaum, V. Di Noto, Journal of Power Sources 493 (2021) 229681.
[5] V. D. Noto, S. Lavina, D. Longo, M. Vidali, Electrochim. Acta 43 (1998) 1225-1237.

Acknowledgements

This work has received support from: (i) the Italian National Recovery and Resilience Plan (NRRP), Mission 04 Component 2, Investment 1.5 - NextGenerationEU, PE2 NEST - Network 4 Energy Sustainable Transition, Spoke 6 Energy Storage; (ii) the National Recovery and Resilience Plan (NRRP), funded by the European Union - NextGenerationEU [Award Number: CNMS named MOST, Concession Decree No. 1033 of June 17, 2022, adopted by the Italian Ministry of University and Research, Spoke 14 “Hydrogen and New Fuels”]; and (iii) the U.S. Army Research Office (Grant Agreement W911NF-21-1-0347-(78622-CH-INT)).