A New (Trifluoromethane)Sulfonylimide Single-Ion Conductor with PEG Spacer for All-Solid-State Lithium-Based Batteries

Gabriele Lingua; Vladislav Y Shevtsov; Petr S Vlasov; Laura Puchot; Claudio Gerbaldi; Alexander S Shaplov

doi:10.1021/acsmaterialslett.4c01647

A New (Trifluoromethane)Sulfonylimide Single-Ion Conductor with PEG Spacer for All-Solid-State Lithium-Based Batteries

ACS Mater Lett. 2024 Nov 15;6(12):5429-5437. doi: 10.1021/acsmaterialslett.4c01647. eCollection 2024 Dec 2.

Authors

Gabriele Lingua^{1

2

3}, Vladislav Y Shevtsov^{4

5}, Petr S Vlasov⁶, Laura Puchot⁴, Claudio Gerbaldi^{1

2}, Alexander S Shaplov⁴

Affiliations

¹ GAME Lab, Department of Applied Science and Technology (DISAT), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
² National Reference Center for Electrochemical Energy Storage (GISEL) - INSTM,Via G. Giusti 9, 50121 Firenze, Italy.
³ POLYMAT, University of the Basque Country UPV/EHU, Joxe Mari Korta Center, Avda. Tolosa 72, 20018 Donostia-San Sebastian, Spain.
⁴ Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, Luxembourg.
⁵ Department of Physics and Materials Science, University of Luxembourg, 2 Avenue de l'Université, L-4365 Esch-sur-Alzette, Luxembourg.
⁶ Department of Macromolecular Chemistry, Saint-Petersburg State University, Universitetsky pr. 26, 198504 Saint-Petersburg, Russia.

Abstract

The choice of ionic-liquid-like monomers (ILM) for single-ion conducting polyelectrolytes (SICPs) is crucial for the performance of all-solid-state lithium batteries. In the current study, we propose a novel approach for development of SICPs via design and synthesis of a new ILM with long poly(ethylene oxide) spacer between methacrylic group and (trifluoromethane)sulfonylimide anion. Its homopolymer shows an ionic conductivity that is ∼5 orders of magnitude higher (9.2 × 10^-8 S cm^-1 at 25 °C), in comparison with previously reported analogues, while the conductivity of its random copolymer with poly(ethylene glycol)methyl ethermethacrylate reaches the levels of 10^-6 and 10^-5 S cm^-1 at 25 and 70 °C, respectively. The copolymer provides excellent thermal (T _onset ≈ 200 °C) and electrochemical (4.5 V vs Li⁺/Li) stabilities, good compatibility with Li metal, and effective suppression of dendrite growth. Li/SICP/LiFePO₄ cells are capable of reversibly operating at different C rates, demonstrating excellent Coulombic efficiency and retaining specific capacity upon prolonged charge/discharge cycling at a relatively high current rate (C/5) at 70 °C.