Preparation Of Nanostructured Fibers By Sol-gel Combined Electrospinning And It's Electrochemistry Characteration

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(â…¡),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.