The development of high-performance Lithium-ion batteries has long been at the forefront of energy technologies, given the urgent need for large-scale deployment of renewable energy sources, together with the electrification of transportation. The electrolyte, which is a fundamental component of such electrochemcal systems, is often the limiting factor directly affecting the performance and safety of the battery [1,2]. In this context, Poly(vinylidene difluoride)-based electrolytes have attracted huge attention due to their interesting ionic conductive properties and capability to overcome safety issues by replacing flamable organic liquid electrolytes [3]. Despite the interest in these polymer electrolytes, the mechanism of Li-ion diffusion in PVDF-based electrolyte is not well understood. Recent experimental studies [4] have argued that residual DMF solvent, which is used during the electrolytes preparation to dissolve the polymer-salt system, solvates Li+ and contributes to the ionic diffusion. Here we have used Density Functional Theory (DFT) to elucidate the role of DMF in the solvation and diffusion of Li+. The interaction of Li+ with DMF molecules and PVDF chains has been computed by constructing Li+(DMF)n(PVDF)m complexes. In addition, molecular dynamics simulation has been performed in order to obtain additional insights on the diffusion of Li+(DMF)n(PVDF)m complex. The atomic structures and formation energies of Li+(DMF)n(PVDF)m complexes, shown in Figure 1, demonstrate that Li+ tends to coordinate up to three DMF molecules rather than directly binding PVDF, indicating that the interaction Li+-DMF is stronger than the interaction of Li+ with PVDF. Increasing the number of ligands, e.g. n+m > 4, Li+(DMF)n complex interacts with PVDF as the second solvation shell. Moreover, our molecular dynamics simulations confirm that the amount of DMF molecules coordinating Li+ affects the mobility of Li+ through PVDF chains. Our results represent a step forwarding in understanding the diffusion mechanism of Li-ion in PVDF-based electrolytes and can be used for the rational design of novel electrolytes with improved performances.

Ceribelli, N., Di Liberto, G., Giordano, L. (2023). Investigation of the key role of DMF solvent in PVDF-based electrolytes. Intervento presentato a: VIII Congresso Nazionale della Divisione di Chimica Teorica e Computazionale della Società Chimica Italiana, Pisa.

Investigation of the key role of DMF solvent in PVDF-based electrolytes

Ceribelli, N;Di Liberto, G;Giordano, L
2023

Abstract

The development of high-performance Lithium-ion batteries has long been at the forefront of energy technologies, given the urgent need for large-scale deployment of renewable energy sources, together with the electrification of transportation. The electrolyte, which is a fundamental component of such electrochemcal systems, is often the limiting factor directly affecting the performance and safety of the battery [1,2]. In this context, Poly(vinylidene difluoride)-based electrolytes have attracted huge attention due to their interesting ionic conductive properties and capability to overcome safety issues by replacing flamable organic liquid electrolytes [3]. Despite the interest in these polymer electrolytes, the mechanism of Li-ion diffusion in PVDF-based electrolyte is not well understood. Recent experimental studies [4] have argued that residual DMF solvent, which is used during the electrolytes preparation to dissolve the polymer-salt system, solvates Li+ and contributes to the ionic diffusion. Here we have used Density Functional Theory (DFT) to elucidate the role of DMF in the solvation and diffusion of Li+. The interaction of Li+ with DMF molecules and PVDF chains has been computed by constructing Li+(DMF)n(PVDF)m complexes. In addition, molecular dynamics simulation has been performed in order to obtain additional insights on the diffusion of Li+(DMF)n(PVDF)m complex. The atomic structures and formation energies of Li+(DMF)n(PVDF)m complexes, shown in Figure 1, demonstrate that Li+ tends to coordinate up to three DMF molecules rather than directly binding PVDF, indicating that the interaction Li+-DMF is stronger than the interaction of Li+ with PVDF. Increasing the number of ligands, e.g. n+m > 4, Li+(DMF)n complex interacts with PVDF as the second solvation shell. Moreover, our molecular dynamics simulations confirm that the amount of DMF molecules coordinating Li+ affects the mobility of Li+ through PVDF chains. Our results represent a step forwarding in understanding the diffusion mechanism of Li-ion in PVDF-based electrolytes and can be used for the rational design of novel electrolytes with improved performances.
abstract + poster
DFT; AIMD; Lithium batteries; PVDF-based quasi solid electrolytes
English
VIII Congresso Nazionale della Divisione di Chimica Teorica e Computazionale della Società Chimica Italiana
2023
2023
open
Ceribelli, N., Di Liberto, G., Giordano, L. (2023). Investigation of the key role of DMF solvent in PVDF-based electrolytes. Intervento presentato a: VIII Congresso Nazionale della Divisione di Chimica Teorica e Computazionale della Società Chimica Italiana, Pisa.
File in questo prodotto:
File Dimensione Formato  
Ceribelli-2023-DCTC.pdf

accesso aperto

Descrizione: Intervento a convegno - Abstract book
Tipologia di allegato: Other attachments
Licenza: Altro
Dimensione 220.32 kB
Formato Adobe PDF
220.32 kB Adobe PDF Visualizza/Apri

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/10281/444878
Citazioni
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
Social impact