锂硫电池用LiPFSD/PVDF/SiO_2复合膜的研究
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摘要
锂硫电池正极活性物质理论比容量高达1 675 m Ah/g,单质硫具有环境友好,资源丰富,价格低廉等优点,因此,锂硫电池最有希望成为下一代二次电池的有力竞争者。硝酸锂是抑制锂硫电池飞梭的常用添加剂,会随着电池循环不断被消耗。不断消耗的硝酸锂难以长期抑制硫负载量较高电池的飞梭。有研究表明锂离子选择透过性聚合物电解质膜能够有效抑制飞梭效应。将聚偏氟乙烯(PVDF)和SiO_2改性并与Celgard膜复合的全氟磺酸双氰胺锂(LiPFSD)单离子聚合物电解质膜应用于锂硫电池中,研究了电解液中无硝酸锂条件下,复合膜对电池性能的影响。膜的厚度为15μm,膜内添加20%PVDF和10%SiO_2,正极硫负载量3.5 mg/cm2的锂硫电池,其首次放电比容量为995 m Ah/g,0.1 C下50次循环后放电比容量为798 m Ah/g,库仑效率维持80%以上。
Lithium-sulfur batteries is highly promising for next generation of batteries due to their high theoreticalspecific energy of 1 675 m Ah/g, abundant resources environment friendly and low cost. Lithium nitrate, commonlyused as shuttle inhibitor in lithium sulfur cell, was continuously consumed during the charge-discharge process,especially in high-sulfur batteries. So lithium nitrate was unable to restrain shuttle for long circle times. Someresearches work show that Li-ion selective polymer electrolytes for lithium-sulfur cells can restrain shuttle effect. Themodification was carried out for perfluorinated ionomer electrolyte with lithium sulfonyl dicyanomethide functionalgroups by the SiO_2 and PVDF. When the quality fraction of SiO_2 and PVDF was 10% and 20% respectively. Lithiumsulfur battery with a positive sulfur load of 3.5 mg/cm2 has a first discharge specific capacity of 995 m Ah/g, 798 m Ah/g for the next 50 cycles at 0.1 C, and the coulomb efficiency maintains over 80%.
Lithium-sulfur batteries is highly promising for next generation of batteries due to their high theoreticalspecific energy of 1 675 m Ah/g, abundant resources environment friendly and low cost. Lithium nitrate, commonlyused as shuttle inhibitor in lithium sulfur cell, was continuously consumed during the charge-discharge process,especially in high-sulfur batteries. So lithium nitrate was unable to restrain shuttle for long circle times. Someresearches work show that Li-ion selective polymer electrolytes for lithium-sulfur cells can restrain shuttle effect. Themodification was carried out for perfluorinated ionomer electrolyte with lithium sulfonyl dicyanomethide functionalgroups by the SiO_2 and PVDF. When the quality fraction of SiO_2 and PVDF was 10% and 20% respectively. Lithiumsulfur battery with a positive sulfur load of 3.5 mg/cm2 has a first discharge specific capacity of 995 m Ah/g, 798 m Ah/g for the next 50 cycles at 0.1 C, and the coulomb efficiency maintains over 80%.
引文
[1]DIAO Y,XIE K,HONG X B,et al.Insights into Li-S battery cathode capacity fading mechanisms irreversible oxidation of active mass during cycling[J].J Electrocheml Soc,2012,159(11):A1816-A1821.
[2]JIN Z Q,XIE K,HONG X B.Electrochemical performance of lithium/sulfur batteries using perfluorinated ionomer electrolyte with lithium sulfonyl dicyanomethide functional groups as functional separator[J].RSC Adv,2013,3:8889-8898.
[3]AFFOUNE A M,AKIFUMI Y A,UMEDA M.Surface observation of solvent-impregnated Nafion membrane with atomic force microscopy[J].Langmuir the ACS Journal of Surfaces&Colloids,2004,20(17):6965.
[4]BAUER I,THIEME S,BRUCKNER J,et al.Reduced polysulfide in lithium-sulfur batteries using Nafion-based separators[J].J Power Sources,2014,251:417-422.
[5]GAO K,HU X G,DAI C S.Crystal structures of electrospun PVDFmembranes and its separator application for rechargeable lithium metal cells[J].Mat Sci Engineering,2006,131:100-105.
[6]LEE J Y,KO D H,LEE Y M,et al.New crosslinking afent as a Lewis acid for solid polymer electrolytes[J].J Power Sources,2007,172(2):603-606.
[7]AHMAD S,AGNIHOTRY S A.Effect ofγ-Al2O3addition on ion dynamics in polymer electrolytes[J].Current Appl Phy,2009,9(1):108-114.
[8]OSINAKA M,WALKOWIAK M,ZALEWSKA A,et al.Study of the role of ceramic filler in composite gel electrolytes based on microporous polymer membranes[J].J Membr Sci,2009,326(2):582-588.
[9]XI J Y,WU Z H,QIU X P,et al.Nafion/SiO2hybrid membrane for vanadium redox flow battery[J].J Power Sources,2007,166:531-536.
[10]GREGORIO R,UENO E M.Effect of crystalline phase,orientation and temperature on the dielectric properties of poly(vinylidene fluoride)(PVDF)[J].Journal of Materials Science,1999,34(18):4489-4500.
[11]LEHMANI A,DURAND-VIDAL S,TURQ P.Surface morphology of Nafion 117 membranes by tapping mode atomic force microscope[J].J Appl Polym Sci,1998,68(3):503-508.
[12]KUMAR B,RODRIGUES S J.Ionic conductivity in colloidal electrolytes[J].Sol Sta Ion,2004,167:91-97.á
[2]JIN Z Q,XIE K,HONG X B.Electrochemical performance of lithium/sulfur batteries using perfluorinated ionomer electrolyte with lithium sulfonyl dicyanomethide functional groups as functional separator[J].RSC Adv,2013,3:8889-8898.
[3]AFFOUNE A M,AKIFUMI Y A,UMEDA M.Surface observation of solvent-impregnated Nafion membrane with atomic force microscopy[J].Langmuir the ACS Journal of Surfaces&Colloids,2004,20(17):6965.
[4]BAUER I,THIEME S,BRUCKNER J,et al.Reduced polysulfide in lithium-sulfur batteries using Nafion-based separators[J].J Power Sources,2014,251:417-422.
[5]GAO K,HU X G,DAI C S.Crystal structures of electrospun PVDFmembranes and its separator application for rechargeable lithium metal cells[J].Mat Sci Engineering,2006,131:100-105.
[6]LEE J Y,KO D H,LEE Y M,et al.New crosslinking afent as a Lewis acid for solid polymer electrolytes[J].J Power Sources,2007,172(2):603-606.
[7]AHMAD S,AGNIHOTRY S A.Effect ofγ-Al2O3addition on ion dynamics in polymer electrolytes[J].Current Appl Phy,2009,9(1):108-114.
[8]OSINAKA M,WALKOWIAK M,ZALEWSKA A,et al.Study of the role of ceramic filler in composite gel electrolytes based on microporous polymer membranes[J].J Membr Sci,2009,326(2):582-588.
[9]XI J Y,WU Z H,QIU X P,et al.Nafion/SiO2hybrid membrane for vanadium redox flow battery[J].J Power Sources,2007,166:531-536.
[10]GREGORIO R,UENO E M.Effect of crystalline phase,orientation and temperature on the dielectric properties of poly(vinylidene fluoride)(PVDF)[J].Journal of Materials Science,1999,34(18):4489-4500.
[11]LEHMANI A,DURAND-VIDAL S,TURQ P.Surface morphology of Nafion 117 membranes by tapping mode atomic force microscope[J].J Appl Polym Sci,1998,68(3):503-508.
[12]KUMAR B,RODRIGUES S J.Ionic conductivity in colloidal electrolytes[J].Sol Sta Ion,2004,167:91-97.á