کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
635148 1456089 2012 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Relationship between morphology and conductivity of block-copolymer based battery separators
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
Relationship between morphology and conductivity of block-copolymer based battery separators
چکیده انگلیسی

Nanoporous battery separators were made by blending a polystyrene-block-polyethylene-block-polystyrene copolymer (SES) and polystyrene (PS) homopolymers, casting films of the blend, and selectively dissolving the homopolymer. The efficacy of the separators thus obtained was determined by measurement of the ionic conductivity of separators soaked in 1 M lithium hexafluorophosphate in ethylene carbonate/diethyl carbonate (1:1, v/v, Novolyte Technologies, Inc.), a standard lithium battery electrolyte. We focus on the effect of chain length of the sacrificial homopolymer on separator morphology and ion transport. In highly porous separators with a nominal pore volume fraction of 0.43, conductivity peaked at α = 0.22, where values as high as 0.39 mS cm−1 were achieved (α is the molecular weight of the PS homopolymer normalized by that of the PS block in the SES copolymer). Nitrogen adsorption experiments and scanning electron microscopy were used to determine the underpinnings of this observation. At α = 0.12, extremely small pores with low surface area are formed. Increasing α to 0.22 results in a film with well-connected nanoscale pores. A further increase in α to 2.02 results in films with micron-sized pores that are not effective for ion transport.


► Battery separators were made by block copolymer/homopolymer blends.
► Pores were made by selective removal of homopolymer.
► Morphology and conductivity were found to depend on homopolymer molecular weight.
► Conductivities obtained were comparable to commercial Celgard® 2400 membranes.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Membrane Science - Volumes 394–395, 15 March 2012, Pages 175–183
نویسندگان
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