聚吡咯修饰氧化铁纳米片改善锂硫电池性能  

Polypyrrole Modified Iron Oxide Nanosheets for Improving Li-S Battery Electrochemical Performance

作　　者：李舒楠 乔明涛 沈凯飞 张玉龙 司渭滨 雷琬莹 雷西萍[1] LI Shunan;QIAO Mingtao;SHEN Kaifei;ZHANG Yulong;SI Weibin;LEI Wanying;LEI Xiping(College of Materials Science and Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;State Grid Ankang Electric Power Supply Company,Ankang 725000,Shaanxi,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,西安710055 [2]国网陕西省电力有限公司安康供电公司,陕西安康725000

出　　处：《硅酸盐学报》2024年第5期1664-1675,共12页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金青年项目(52302112);陕西省教育厅重点科学研究计划项目(22JY037)。

摘　　要：采用酸刻蚀诱导的原位生长法在α-Fe_(2)O_(3)纳米片表面修饰聚吡咯,其中对甲苯磺酸起到刻蚀与掺杂的作用,Fe_(2)O_(3)纳米片表面被刻蚀出的Fe^(3+)作为氧化剂,使得吡咯在Fe_(2)O_(3)纳米片表面聚合生长,对甲苯磺酸根作为对阴离子掺杂于聚吡咯分子结构中,得到Fe_(2)O_(3)@PPy复合纳米片。通过调节刻蚀环境与Fe_(2)O_(3)纳米片的投料量控制聚吡咯的修饰量,制得系列Fe_(2)O_(3)@PPy复合纳米片。当对甲苯磺酸和Fe_(2)O_(3)摩尔比为12:1时,Fe_(2)O_(3)@PPy复合纳米片获得优异的电化学性能。1 C下的初始容量为468.7 mA·h·g^(-1),循环500次后仍保持414.5 mA·h·g^(-1)的容量,容量保持率为86.2%,表现出良好的循环稳定性。该材料可应用于动力电池的开发。Introduction Lithium sulfur batteries have attracted recent attention as the secondary batteries with a high specific energy,a long lifespan,and a high safety.Inhibiting the shuttle effect of polysulfides and improving reaction kinetics become challenges.The chemical interactions between polar metal compounds and polysulfide ions(i.e.,polarity polarity interactions,Lewis acid-base interactions,and sulfur bond chain reactions)have some advantages in inhibiting the shuttle effect of polysulfide ions.In addition,many metal compounds exhibit an electrocatalytic activity during the conversion of polysulfides,promoting the conversion rate of polysulfide ions during charging and discharging,suppressing the uneven deposition of insoluble sulfides Li2S2/Li2S on the electrode surface,and thus achieving a goal of improving the utilization rate of active substances,inhibiting shuttle,and reducing the loss of active substances.The inherent conductive properties of conductive polymers are conducive to electron conduction,and their soft and elastic properties can effectively buffer the volume expansion of active substances during charge and discharge processes.The functional groups rich in them have a strong affinity for Li PSs and can inhibit shuttle effects.In this paper,Fe_(2)O_(3)@PPy composite materials were prepared via in-situ growth of polypyrrole on Fe_(2)O_(3) nanosheets by acid etching.Methods Fe_(2)O_(3) nanosheets were modified by a simple one-step method with polypyrrole to prepare high-performance lithium sulfur battery composite cathode materials.Fe_(2)O_(3) nanosheets were placed in a solution of p-toluenesulfonic acid,and the surface was exposed to Fe^(3+)by acid etching.Fe^(3+)acted as an oxidant to promote the oxidation polymerization reaction of pyrrole monomers on the surface of the nanosheets.Also,p-toluenesulfonic acid was doped into the molecular structure of polypyrrole to obtain Fe_(2)O_(3)@PPy composite nanosheets.A series of Fe_(2)O_(3)@PPy composite nanosheets were prepared via adjusting the etchin

关 键 词：三氧化二铁 聚吡咯 纳米片 原位生长 锂硫电池 

分 类 号：TM912[电气工程—电力电子与电力传动]