负载无定型Fe纳米颗粒的掺氮碳笼修饰隔膜对锂硫电池电化学性能的影响  

Effect of Nitrogen-doped Carbon Cage Loaded with Amorphous Fe Nanoparticles Modified Separator on Electrochemical Performance of Lithium-sulfur Battery

作　　者：霍雨 孙骞 马成[1] 王际童[1] 乔文明[1] 余子舰 张寅旭 HUO Yu;SUN Qian;MA Cheng;WANG Jitong;QIAO Wenming;YU Zijian;ZHANG Yinxu(State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;Hesheng Silicon Industry(Shanshan)Co.Ltd.,Tolufan 838200,China)

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237 [2]合盛硅业(鄯善)有限公司,吐鲁番838200

出　　处：《高等学校化学学报》2024年第12期133-142,共10页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:22178107,U21A2060,22178116,21978097);新疆维吾尔自治区重点研发计划项目(批准号:2022B01030)资助.

摘　　要：为了抑制多硫化物的穿梭效应并提高锂硫电池充放电过程的可逆性,本文以Fe掺杂的ZIF-8为前驱体,通过高温碳化合成了一种多孔富氮碳笼担载的无定型Fe纳米颗粒(Fe-CNx),并将其作为锂硫电池隔膜改性层.结果表明,Fe-CNx表面的Fe原子和N原子分别与多硫化物中的S原子和Li原子发生键合作用,从而限制了LiPS的扩散和穿梭.Fe原子的引入降低了多硫化物转化反应的过电势,加快了氧化还原动力学.采用Fe-CNx隔膜的锂硫电池在0.2C倍率下循环100次后,电池的放电比容量仍然能维持在初始容量的94.3%,即使在3.0C高倍率时也能表现出高达660 mA·h/g的高比容量,经过1.0C倍率下800次的长循环后剩余比容量依旧达到了603.2 mA·h/g,表现出优异的电化学性能.To suppress the shuttle effect of polysulfides and improve the reversibility of redox reactions in lithium-sulfur battery,a porous nitrogen-rich carbon nanocage loaded with amorphous Fe nanoparticles(Fe-CNx)was synthesized by high temperature carbonization with Fe-ZIF-8 as the precursor.The results show that the Fe and N atoms on the surface of Fe-CNx are bonded with S and Li atoms in lithium polysulfides(LiPS),respectively,thus limiting the diffusion and shuttle of LiPS.In addition,the introduction of Fe atoms reduced the overpotential of LiPS conversion reaction and accelerated the redox kinetics.Therefore,the lithium-sulfur(Li-S)battery with Fe-CNx separator shows excellent electrochemical performance:the specific capacity of the battery can still be maintained at 94.3% of the initial capacity after 100 cycles of 0.2C,and the high specific capacity of 660 mA·h/g can be achieved even at high rate of 3.0C,and the residual specific capacity can still reach 603.2 mA·h/g after long cycles of 800 at 1.0C.

关 键 词：锂硫电池 催化作用 反应动力学 修饰隔膜 

分 类 号：O646[理学—物理化学]