李丽红,王永常,高翔,朱世平

• 1:化学工程联合国家重点实验室(浙江大学)
• 2:浙江大学化学工程与生物工程学院
• 3:浙江省能源与核技术应用研究所
• 4:Department of Chemical Engineering McMaster University

摘要(Abstract)：

硫正极材料因具有较高的能量密度而广受关注,但由于其在充放电过程中体积变化大、硫穿梭效应使其容量衰退快等原因,大大限制了其实际使用。本文通过RAFT乳液聚合首次设计合成了聚(苯乙烯-b-丙烯酸正丁酯-b-苯乙烯)(Sn BAS)三嵌段共聚物作为硫电极粘结剂。通过制备粘结剂薄膜测试其在醚类电解液的溶胀性,并进行多倍率充放电、电池寿命测试,与聚苯乙烯(PS)、聚丙烯酸正丁酯(Pn BA)及商用SBR对比,发现通过调配苯乙烯/丙烯酸正丁酯(St/n BA)质量比率可获得兼具高力学强度及高电解液溶胀率的电极粘结剂。将粘结剂Sn BAS100用于制备硫电极,所得硫正极分别在0.1C、0.2C、0.5C、1C、2C、0.1C倍率充放电后,再次以0.2C倍率充放电所得放电比容量为781 m Ah×g-1,与首次充放电时的放电比容量1061 m Ah×g~(-1)相比,容量保留率为73.6%。电极继续100次循环后放电比容量为740m Ah×g~(-1),容量保留率为94.7%,每次充放电的平均容量衰退率为0.05%。结果表明,水溶性嵌段结构的SnBAS粘结剂是一种极具应用潜力的水基硫正极粘结剂。

关键词(KeyWords)： 硫电极;水溶性粘结剂;嵌段共聚物;聚(苯乙烯-b-丙烯酸正丁酯-b-苯乙烯)

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金(21574115);; 浙江省科技计划项目(2015F50022)

作者(Author): 李丽红,王永常,高翔,朱世平

参考文献(References)：

• [1]Bao W,Zhang Z,Gan Y,et al.Enhanced cyclability of sulfur cathodes in lithium-sulfur batteries with Na-alginate as a binder[J].Journal of Energy Chemistry,2013,22(5):790-794.
• [2]Xu R,Lu J,Amine K.Progress in mechanistic understanding and characterization techniques of Li-S batteries[J].Advanced Energy Materials,2015,5(16):1500408-1500429.
• [3]Wang J,Yao Z,Monroe C W,et al.Carbonyl-β-cyclodextrin as a novel binder for sulfur composite cathodes in rechargeable lithium batteries[J].Advanced Functional Materials,2013,23(9):1194-1201.
• [4]Sun J,Huang Y,Wang W,et al.Application of gelatin as a binder for the sulfur cathode in lithium-sulfur batteries[J].Electrochimica acta,2008,53(24):7084-7088.
• [5]Li G,Ling M,Ye Y,et al.Acacia senegal–inspired bifunctional binder for longevity of lithium-sulfur batteries[J].Advanced Energy Materials,2015,5(21):1500878-1500885.
• [6]Bhattacharya P,Nandasiri M I,Lv D,et al.Polyamidoamine dendrimer-based binders for high-loading lithium-sulfur battery cathodes[J].Nano Energy,2016,19:176-186.
• [7]Cai W,Li G,He F,et al.A novel laminated separator with multi functions for high-rate dischargeable lithium-sulfur batteries[J].Journal of Power Sources,2015,283:524-529.
• [8]Rao M,Li X,Liao Y,et al.Preparation and performance of a composite polyimide/poly(vinylidene fluoride-co-hexafluoropropylene)/nano-Al2O3 polymer electrolyte for lithium-sulfur cell[J].Ionics,2015,21(7):1937-1943.
• [9]Zhang Y,Zhao Y,Gosselink D,et al.Synthesis of poly(ethylene-oxide)/nanoclay solid polymer electrolyte for all solid-state lithium/sulfur battery[J].Ionics,2015,21(2):381-385.
• [10]Lu H,Yuan Y,Hou Z,et al.Solvate ionic liquid electrolyte with 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether as a support solvent for advanced lithium–sulfur batteries[J].RSC Advances,2016,6(22):18186-18190.
• [11]Chou S L,Pan Y,Wang J Z,et al.Small things make a big difference:binder effects on the performance of Li and Na batteries[J].Physical Chemistry Chemical Physics,2014,16(38):20347-20359.
• [12]Sekhon S S,Singh H P.Ionic conductivity of PVd F-based polymer gel electrolytes[J].Solid State Ionics,2002,152:169-174.
• [13]Magistris A,Mustarelli P,Parazzoli F,et al.Structure,porosity and conductivity of PVd F films for polymer electrolytes[J].Journal of power sources,2001,97:657-660.
• [14]Magistris A,Quartarone E,Mustarelli P,et al.PVDF-based porous polymer electrolytes for lithium batteries[J].Solid State Ionics,2002,152:347-354.
• [15]Pan J,Xu G,Ding B,et al.Enhanced electrochemical performance of sulfur cathodes with a water-soluble binder[J].RSC Advances,2015,5(18):13709-13714.
• [16]Rao M,Song X,Liao H,et al.Carbon nanofiber–sulfur composite cathode materials with different binders for secondary Li/S cells[J].Electrochimica Acta,2012,65:228-233.
• [17]Kim C S,Guerfi A,Hovington P,et al.Importance of open pore structures with mechanical integrity in designing the cathode electrode for lithium–sulfur batteries[J].Journal of Power Sources,2013,241:554-559.
• [18]Lacey M J,Jeschull F,Edstr M K,et al.Functional,water-soluble binders for improved capacity and stability of lithium–sulfur batteries[J].Journal of Power Sources,2014,264:8-14.
• [19]WU Ying-lei(伍英蕾),YANG Jun(杨军),WANG Jiu-lin(王久林),et al.Composite cathode structure and binder for high performance lithium-sulfur battery(高性能锂-硫电池用复合正极的构造与粘结剂)[J].Acta Physico-Chimica Sinica(物理化学学报),2010,26(2):283-290.
• [20]Nakazawa T,Ikoma A,Kido R,et al.Effects of compatibility of polymer binders with solvate ionic liquid electrolytes on discharge and charge reactions of lithium-sulfur batteries[J].Journal of Power Sources,2016,307:746-752.
• [21]Zhang Z,Bao W,Lu H,et al.Water-soluble polyacrylic acid as a binder for sulfur cathode in lithium-sulfur battery[J].ECS Electrochemistry Letters,2012,1(2):A34-A37.
• [22]Duan X,Han Y,Li Y,et al.Improved capacity retention of low cost sulfur cathodes enabled by a novel starch binder derived from food[J].RSC Advances,2014,4(105):60995-61000.
• [23]Zhang S S,Tran D T,Zhang Z.Poly(acrylic acid)gel as a polysulphide blocking layer for high-performance lithium/sulphur battery[J].J Mater Chem A,2014,2(43):18288-18292.
• [24]Seh Z W,Zhang Q,Li W,et al.Stable cycling of lithium sulfide cathodes through strong affinity with a bifunctional binder[J].Chemical Science,2013,4(9):3673-3677.
• [25]WANG Xiao-guang(王晓光).Mechanism of RAFT emulsion polymerization and synthesis ofpoly(styrene-b-n-butylacrylate-b-styrene)RAFT乳液聚合机理及聚(苯乙烯-b-丙烯酸丁酯-b-苯乙烯)的制备)[D].Hangzhou(杭州):Zhejiang University(浙江大学),2011.
• [26]Han Z J,Yabuuchi N,Shimomura K,et al.High-capacity Si-graphite composite electrodes with a self-formed porous structure by a partially neutralized polyacrylate for Li-ion batteries[J].Energy&Environmental Science,2012,5(10):9014-9020.
• [27]Olsher U,Izatt R M,Bradshaw J S,et al.Coordination chemistry of lithium ion:a crystal and molecular structure review[J].Chemical Reviews,1991,91(2):137-164.
• [28]Ferguson C J,Hughes R J,Nguyen D,et al.Ab initio emulsion polymerization by RAFT-controlled self-assembly[J].Macromolecules,2005,38(6):2191-2204.
• [29]Wang X,Luo Y,Li B,et al.Ab initio batch emulsion RAFT polymerization of styrene mediated by poly(acrylic acid-b-styrene)trithiocarbonate[J].Macromolecules,2009,42(17):6414-6421.
• [30]ZHAN Jin-hua(詹晋华),XIAN Qiao-yan(冼巧妍),DAI Yan-shan(戴燕珊).Application of the water-soluable binder for electrodes of Li-ion batteries(水溶性粘合剂在锂离子电池电极中的应用)[J].Battery Bimonthly(电池),2001,31(3):123-125.
• [31]Huang J,Zhao S,Gao X,et al.RAFT Ab initio emulsion polymerization of styrene using poly(acrylic acid)-b-polystyrene trithiocarbonate of various structures as mediator and surfactant[J].Macromolecular Reaction Engineering,2014,8(10):696-705.
• [32]Moineau C,Minet M,TeyssiéP,et al.Synthesis and characterization of poly(methyl methacrylate)-block-poly(n-butyl acrylate)-block-poly(methyl methacrylate)copolymers by two-step controlled radical polymerization(ATRP)catalyzed by Ni Br2(PPh3)2,1[J].Macromolecules,1999,32(25):8277-8282.
• [33]Mark J E.Physical properties of polymers handbook[M].New York:Springer,2007.
• [34]Luo Y,Wang X,Zhu Y,et al.Polystyrene-block-poly(n-butyl acrylate)-block-polystyrene triblock copolymer thermoplastic elastomer synthesized via RAFT emulsion polymerization[J].Macromolecules,2010,43(18):7472-7481.
• [35]Ahmad N M,Heatley F,Lovell P A.Chain transfer to polymer in free-radical solution polymerization of n-butyl acrylate studied by NMR spectroscopy[J].Macromolecules,1998,31(9):2822-2827.
• [36]Marsella M J,Swager T M.Designing conducting polymer-based sensors:selective ionochromic response in crown ether-containing polythiophenes[J].Journal of the American Chemical Society,1993,115(25):12214-12215.
• [37]Pei Q,Yang Y.Efficient photoluminescence and electroluminescence from a soluble polyfluorene[J].Journal of the American Chemical Society,1996,118(31):7416-7417.
• [38]Wu M,Xiao X,Vukmirovic N,et al.Toward an ideal polymer binder design for high-capacity battery anodes[J].Journal of the American Chemical Society,2013,135(32):12048-12056.