Polyethylene Oxide-Coated Electrospun Polyimide Fibrous Seperator for High-Performance Lithium-Ion Battery
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2016年第3期
论文作者：Xingxing Liang Ying Yang Jie Cheng
文章页码：200 - 206
摘 要：A polyethylene oxide（PEO）-coated polyimide（PI） membrane was prepared by electrospinning method followed by a dip-coating and drying process for high-performance lithium-ion batteries（LIB）. Semicrystal PEO was covered on the surface of the fibers and partially enmeshed in PI matrix, which formed unique porous structures. The pores with an average size of 4.1 μm and a porosity of 90% served as ion transport channels. Compared with the cell with Celgard 2400 membrane, the half-cell using PEO-coated PI membrane as a separator exhibits excellent electrochemical performance both at room temperature and at low temperature. The electrolyte uptaking rate of PEO-coated PI membrane was 170% and the ionic conductivity was 3.83 × 10–3S cm–1. PEO-coated PI membrane possessed 5.3 V electrochemical window.The electrode–electrolyte interfacial resistance was 62.4 Ω. The capacity retention ratios with PEOcoated PI membrane were 86.4% at 5 C and 73.5% at 10 C at 25 ℃ and 75% at 5 C at 0 ℃. Furthermore,the cell using the separator demonstrates excellent capacity retention over cycling. These advanced characteristics would boost the application of the PEO-coated PI membrane for high-power lithium ion battery.
Xingxing Liang1,2，Ying Yang1,3，Jie Cheng5
1. Department of Electrical Engineering, Tsinghua University3. State Key Lab. of Power System, Tsinghua University5. Research Institute of Chemical Defense
摘 要：A polyethylene oxide（PEO）-coated polyimide（PI） membrane was prepared by electrospinning method followed by a dip-coating and drying process for high-performance lithium-ion batteries（LIB）. Semicrystal PEO was covered on the surface of the fibers and partially enmeshed in PI matrix, which formed unique porous structures. The pores with an average size of 4.1 μm and a porosity of 90% served as ion transport channels. Compared with the cell with Celgard 2400 membrane, the half-cell using PEO-coated PI membrane as a separator exhibits excellent electrochemical performance both at room temperature and at low temperature. The electrolyte uptaking rate of PEO-coated PI membrane was 170% and the ionic conductivity was 3.83 × 10–3S cm–1. PEO-coated PI membrane possessed 5.3 V electrochemical window.The electrode–electrolyte interfacial resistance was 62.4 Ω. The capacity retention ratios with PEOcoated PI membrane were 86.4% at 5 C and 73.5% at 10 C at 25 ℃ and 75% at 5 C at 0 ℃. Furthermore,the cell using the separator demonstrates excellent capacity retention over cycling. These advanced characteristics would boost the application of the PEO-coated PI membrane for high-power lithium ion battery.
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