【作者】 刘芳芳；

【导师】 陈代荣； 焦秀玲；

【作者基本信息】 山东大学 ， 无机化学， 2008， 硕士

【摘要】 本论文主要讨论溶胶凝胶结合电纺技术合成纳米结构纤维,并测试其作为锂离子电池正极材料的电化学性质。第一章主要分三部分,分别介绍了溶胶凝胶化学、电纺技术和锂离子电池。第一部分主要介绍了溶胶凝胶-电纺的基本原理,通过描述其基本过程揭示最终产物的影响因素,并简单介绍了溶胶凝胶-电纺技术的国内外概况;第二部分主要介绍了锂离子电池对正极材料的要求,并详细介绍了锂离子电池正极材料的发展,以及纳米结构纤维材料作为正极材料的优势。第三节说明了本文的选题思路及研究目的。第二章主要介绍了核壳结构Li(Ni_1/3Co_1/3Mn_1/3)O₂/Li(Ni_1/2Mn_1/2)O₂纳米纤维的合成、表征及其作为锂离子电池正极材料的电化学性质表征。本实验采用醋酸盐为原料提供锂离子及过渡金属离子（钴、镍、锰）,以柠檬酸为螯合剂,去离子水为溶剂通过溶胶凝胶法合成可纺性溶胶,对溶胶进行同轴电纺得到核壳结构纳米纤维,将纤维干燥后在不同温度下对其进行烧结,在700℃得到最终晶化产物:核壳结构Li(Ni_1/3Co_1/3Mn_1/3)O₂/Li(Ni_1/2Mn_1/2)O₂纳米纤维。我们对样品进行了TG、IR、XRD、TEM、SEM等基本表征,以确定样品的烧结过程中组分和结构的演化,以及样品的晶化程度和形貌变化。并将核壳结构纳米纤维Li(Ni_1/3Co_1/3Mn_1/3)O₂/Li(Ni_1/2Mn_1/2)O₂作为锂离子电池正极材料,通过组装锂离子电池,测试了电池的充放电性能和循环性能。第三章主要介绍了中空纳米结构Li(Ni_0.8Co_0.2)O₂纤维的合成、表征及其作为锂离子电池正极材料的电化学性质表征。同样以醋酸盐提供金属离子,柠檬酸为螯合剂,PVP为添加剂,去离子水为溶剂通过溶胶凝胶过程合成可纺性溶胶,再通过单管电纺过程得到纤维结构,经过烧结后得到最终产物:中空纳米结构Li(Ni_0.8Co_0.2)O₂纤维。对样品进行了TG、IR、XRD、TEM及SEM等基本表征,以确定样品的烧结过程中组分和结构的演化,以及样品的晶化程度和形貌变化。并将中空纳米结构Li(Ni_0.8Co_0.2)O₂纤维作为锂离子电池正极材料,通过组装锂离子电池,测试电池的充放电性能和循环性能。第四章主要介绍了纳米结构LiFePO₄纤维的制备、基本表征其作为锂离子电池正极材料的电化学性质表征。本实验以二价铁源为原料,以醋酸锂提供锂离子、以柠檬酸为螯合剂、去离子水为溶剂,在70℃水浴中形成可纺性溶胶;通过电纺过程形成纳米结构纤维。再于惰气下进行烧结,最终形成纳米结构LiFePO₄纤维。我们对样品进行了TG、IR、XRD、TEM及SEM等基本表征,以确定样品烧结过程中组分和结构的演化,以及样品的晶化程度和形貌变化。并将纳米结构LiFePO₄纤维作为锂离子电池正极材料,通过组装锂离子电池,测试电池的充放电性能和循环性能。更多还原

【Abstract】 The nanostructured fibers were synthesized by a sol-gel process combined with electrospinning technique.The contents include the preparation of the fibers and the investigation of electrochemical performance as cathode materials for lithium ion batteries.In chapter one,we introduced three contents:the sol-gel process,the technique of electrospining,lithium-ion batteries.The first part,include the phylogeny,character, principle,process of the sol-gel process,and the influence of the processing parameters on every step.In the second part,we introduced the phylogeny,principle and procedures of the electrospinning,especially in the modification of collector and spinneret and the main factors effecting on the structure and shape of the fiber.In the third part,we introduced the phylogeny,principle and composing of lithium-ion batteries,especially in the development of cathode materials of lithium-ion batteries. In the end,we also described why and how chose this thesis.In chapter two,the nanostructured Li(Ni_1/3Co_1/3Mn_1/3)O₂/Li(Ni_1/2Mn_1/2)O₂ fibers were prepared by electrospinning combined with the sol-gel method.Using metal acetate as starting materials,citric acid as chelating agent to synthesize sol; electrospinning the sol to gain fiber structure,sinter the fiber to gain the final production:core-shell Li(Ni_1/3Co_1/3Mn_1/3)O₂/Li(Ni_1/2Mn_1/2)O₂ nanostructured fiber. Characterize the final fiber with TG,IR,XRD,TEM,SEM ect.and testing it’s electrochemical characteration as cathode material of lithium ion battery.In chapter three,the nanostructured Li(Ni_0.8Co_0.2)O₂ fibers were prepared by electrospinning combined with the sol-gel method.Using metal acetate as starting materials,citric acid as chelating agent and PVP as additive to synthesize sol; electrospinning the sol to gain fiber structure,sinter the fiber to gain the final production:nanostructured Li(Ni_0.8Co_0.2)O₂ fiber.As the additive increased the final morphology are different with each other.The same as chapter two,we characterize the final fiber with TG,IR,XRD,TEM,SEM ect.and testing it’s electrochemical characteration as cathode material of lithium ion battery.In chapter four,the nanostructured LiFePO₄ fibers were prepared by electrospinning combined with the sol-gel method.Using Fe（Ⅱ）,lithium acetate, and citric acid as chelating agent to synthesize sol;electrospinning the sol to gain fiber structure,sinter the fiber in inert gas to gain the final production:LiFePO₄ nanostructured fiber.Characterized the final fiber with TG,IR,XRD,TEM,SEM ect. and testing it’s electrochemical characteration as cathode material of lithium ion battery.更多还原