Preparation of Poly(vinylidene fluoride) Lithium‐Ion Battery Separators and Their Compatibilization with Ionic Liquid – A Green Solvent Approach. Issue 19 (4th July 2017)

• Record Type: Journal Article
• Authors: Costa, Carlos M.; Rodrigues, Henrique M.; Gören, Attila; Machado, Ana V.; Silva, Maria M.; Lanceros‐Méndez, Senentxu
• Is Part Of: ChemistrySelect. Volume 2:Issue 19(2017)
• Page Start: 5394
• Page End: 5402
• Publication Date: 2017-07-04
• Subjects: Green solvent -- Ionic liquid -- Lithium-ion batteries -- PVDF separator; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201701028
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Battery separator membranes for lithium‐ion batteries have been developed based on poly(vinylidene fluoride), PVDF, and using the "green solvent" ‐ N, N'‐dimethylpropyleneurea (DMPU). This separator presents a porous microstructure with a degree of porosity of 20 % and pore size below 1 μm, showing excellent mechanical properties. Further, its ionic conductivity, tortuosity and MacMullin number values are 0.1 mS.cm −1, 4 and 82, respectively. This PVDF separator membrane was evaluated in Li/C–LiFePO4 half‐cells with electrolyte solution showing good cyclability and rate capability, with a discharge value after 50 cycles of 56 mAh.g −1 at C, corresponding to 50 % of the capacity retention. Its electrochemical performance soaked in ionic liquid presents a discharge capacity of 45 mAh.g −1 at C/5‐rate and capacity retention of 60%, respectively. Thus, this separator is an appropriate candidate for environmentally friendlier and safer lithium‐ion batteries. Abstract : A green solvent approach was used for the development of battery separator membranes based on Poly(vinylidene fluoride), PVDF. Conventional and ionic liquid were used as electrolytes. In the latter case a discharge capacity of 45 mAh.g −1 at C/5‐rate and discharge capacity retention of 60% after 10 cycles were obtained. This work represents a contribution towards environmentally friendlier lithium‐ion batteries.