Enhanced ionic conductivity in poly(vinylidene fluoride) electrospun separator membranes blended with different ionic liquids for lithium ion batteries

Autor: Daniela M. Correia, Maria Manuela Silva, Renato Ferreira Gonçalves, V. de Zea Bermudez, Senentxu Lanceros-Méndez, J.C. Barbosa, Carlos M. Costa
Přispěvatelé: Universidade do Minho
Rok vydání: 2021
Předmět:
Zdroj: Repositório Científico de Acesso Aberto de Portugal
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP
ISSN: 0021-9797
DOI: 10.1016/j.jcis.2020.08.046
Popis: Electrospun poly(vinylidene fluoride) (PVDF) fiber membranes doped with different ionic liquids (ILs) and sharing the same anion were produced and their potential as separator membranes for battery applications was evaluated. Different types of ILs containing the same anion, bis(trifluoromethylsulfonyl)im ide [TFSI] , were used with IL concentrations ranging between 0 and 15 wt% The morphology, microstructure, thermal and electrical properties (ionic conductivity and electrochemical window) of the membranes were evaluated. The presence of ILs in the PVDF polymer matrix influences the fiber diameter and the content of the polar 13 phase within the polymer, as well as the degree of crystallinity. The thermal stability of the membranes decreases with the incorporation of IL. Impedance spectroscopy tests show a maximum ionic conductivity of 2.8 mS.cm(-1) for 15% of 1-ethyl-3-methylimidazolium bis(tri fluoromethylsulfonyl)imide ([Emim][TFSI]) at room temperature. The electrochemical stability of the samples ranges from 0.0 to 6.0 V. When evaluated as battery separator membranes in C-LiFePO4 halfcells, a maximum discharge capacity of 119 mAh.g(-1) at C-rate was obtained for the PVDF membrane with 15% [Emim][TFSI], with a coulombic efficiency close to 100%. The results demonstrate that the produced electrospun membranes are suitable for applications as separators for lithium ion batteries (LIBs).
Work supported by the Portuguese Foundation for Science and Technology (FCT): projects UID/FIS/04650/2019, UID/QUI/0686/2019, UID/CTM/50025/2019, UID/QUI/50006/2019, PTDC/FIS-MAC/28157/2017, and Grants SFRH/BD/140842/2018 (J.C.B.), SFRH/BPD/121526/2016 (D.M.C), CEECIND/00833/2017 (R.G.) and SFRH/BPD/112547/2015 (C.M.C.). Financial support from the Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-1060 99RB-C43/AEI/10.13039/501100011033 and from the Basque Government Industry and Education Departments under the ELKARTEK and HAZITEK programs is also acknowledged.
Databáze: OpenAIRE
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