RT Journal Article T1 On the structure of hybrid water-in-salt electrolytes A1 Lois-Cuns, Raúl A1 Santiago Alonso, Antía A1 Otero Lema, Martín A1 Parajó Vieito, Juan José A1 Salgado Carballo, Josefa A1 Montes-Campos, Hadrián A1 Méndez-Morales, Trinidad A1 Varela Cabo, Luis Miguel AB Water-in-salt electrolytes are promising candidates for next-generation lithium-ion batteries due to their enhanced safety and cost-effectiveness. However, optimizing the performance of hybrid aqueous/non-aqueous water-in-salt electrolytes remains a challenge. This work investigates the structural characteristics of mixtures of a LiTFSI water-in-salt based electrolyte (21 m) with several common solvents (e.g. carbonates, dimethyl sulfoxide, acetonitrile) using molecular dynamics simulations combined with experimental measurements. Our analysis reveals a correlation between the ability of a given cosolvent to solvate lithium cations and its Lewis basicity. A strong Lewis basicity favours the formation of free water cluster aggregates in the system, which reduces the electrochemical performance of the electrolyte. Moreover, the relative permittivity of the cosolvents also plays an important role in modifying the ionic interaction. PB Royal Society of Chemistry YR 2025 FD 2025-06-16 LK https://hdl.handle.net/10347/42434 UL https://hdl.handle.net/10347/42434 LA eng NO Lois-Cuns R, Santiago-Alonso A, Otero-Lema M, Parajó JJ, Salgado J, Montes-Campos H, Méndez-Morales T, Varela LM. On the structure of hybrid water-in-salt electrolytes. Phys Chem Chem Phys. 2025 Jun 25;27(25):13629-13644. doi: 10.1039/d5cp00680e. PMID: 40521937. NO The financial support from the Spanish Ministry of Science, Innovation and Universities (PID2021-126148NA-I00 funded by MICIU/AEI/10.13039/501100011033/FEDER, UE) is gratefully acknowledged. This work is part of the project CNS2023- 144785, funded by MICIU/AEI/10.13039/501100011033 and the European Union ‘‘NextGenerationEU’’/PRTR. Moreover, this work was funded by the Xunta de Galicia (GRC ED431C 2024/ 06). This work was done within the framework of project HI_ MOV – ‘‘Corredor Tecnolo´gico Transfronterizo de Movilidad con Hidro´geno Renovable’’, with reference 0160_HI_MOV_1_E, co-financed by the European Regional Development fund (ERDF), in the scope of Interreg VI A Spain – Portugal Cooperation Program (POCTEP) 2021–2027. R. L. C. acknowledges his Predoctoral Contract under the framework of the projects PID2021-126148NA-I00 funded by MCIN/AEI/10.13039/ 501100011033/FEDER, UE; and CNS2023-144785, funded by MICIU/AEI/10.13039/501100011033 and the European Union ‘‘NextGenerationEU’’/PRTR. A. Santiago-Alonso acknowledges funding to the Doutoramento Industrial program from GAINXunta de Galicia. M. O. L. thanks the Xunta de Galicia for his ‘‘Axudas de apoio a´ etapa predoutoral’’ grant (ED481A 2022/236). J. J. Parajo´ (ED481D 2023/014) thanks the I2C postdoctoral program of the Xunta de Galicia for their support in funding the study. H. M. C. thanks the USC for his ‘‘Convocatoria de Recualificacio´n do Sistema Universitario Espan˜ol-Margarita Salas’’ postdoctoral grant under the ‘‘Plan de Recuperacio´n Transformacio´n’’ program funded by the Spanish Ministry of Universities with European Union’s NextGenerationEU funds. This publication and the contract of T. M. M. are part of the grant RYC2022-036679-I, funded by MICIU/AEI/10.13039/ 501100011033 and FSE+. The authors acknowledge M. Martı´n (RIAIDT-USC) for the technical support in NMR measurements. Facilities provided by the Galician Supercomputing Centre (CESGA) are also acknowledged. DS Minerva RD 24 abr 2026