Hugo CRUZ1, Karolina ZALEWSKA1, Sandra GAGO1, Luis BRANCO1
1LAQV-REQUIMTE-FCT-UNL, Lisbon, Portugal
Electrochemical energy storage systems have gained increasing attention, being the most used batteries and supercapacitors (SCs), including the asymmetric (ASCs) ones[1–4].
Batteries are relatively low power devices with high energy storage capacity and longer charge/ discharge times, while SCs and ASCs are high power devices that can be charged and discharged in seconds/few minutes with high efficiency for many cycles. Despite their higher capacitance, energy density is still strongly limited by the working voltage window, particularly when safe and more sustainable aqueous electrolytes are used. Thus, new alternatives must be found[4].
Recently, DESs have been described as a new class of RTIL analogues, having similar physical and chemical properties but with greater potential as environmentally friendly and inexpensive alternatives to RTILs. DES are obtained by mixing a hydrogen-bond acceptor (HBA) with a hydrogen-bond donor (HBD), which interact through H-bonding to generate a larger non-symmetrical ion, hence decreasing the melting point.
Our team has explored a series of low cost, recyclable and green DES based electrolytes for electrochromic devices (ECD) and DSSCs[5-10].
Acknowledgments
The authors thank Fundação para a Ciência e Tecnologia for the projects MIT- EXPL/CS/0055/2021 and PEst-
C/LA0006/2013. The NMR spectrometers are part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project N° 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC).
References
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S. Pan, M. Yao, J. Zhang, B. Li, C. Xing, X. Song, Frontiers in Chemistry. 8 (2020) 1–18 [3] P. Navalpotro, J. Palma, M. Anderson, R. Marcilla, J. Power Sources 306 (2016) 711–717
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