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目录中文摘要........................................................................................................................1英文摘要........................................................................................................................21绪论............................................................................................................................41.1锂离子电池的工作原理及特点......................................................................41.2锂离子电池正极材料LiFePO4的结构及优缺点...........................................71.3锂离子电池正极材料LiFePO4的结构对材料性能的影响...........................91.4锂离子电池正极材料LiFePO4的改性方法...................................................91.5锂离子电池正极材料LiFePO4的合成方法.................................................131.6LiFeP04电池的产业化及应用前景..............................................................152LiFePO4的合成.....................................................................................................172.1实验药品.......................................................................................................172.2实验仪器.......................................................................................................172.3实验步骤.......................................................................................................182.4正极片的制作.............................................................................................182.5纽扣电池的组装.........................................................................................182.6LiFePO4的性能测试...................................................................................192.6.1X-射线衍射分析（XRD）.................................................................192.6.2SEM测试..........................................................................................192.6.3恒流充放电测试...............................................................................202.6.4循环伏安实验（CV）.......................................................................203结果与讨论............................................................................................................213.1样品的X射线衍射分析（XRD）.............................................................213.2样品的扫描电子显微镜分析(SEM)............................................................223.3LiFePO4的循环伏安曲线..............................................................................243.4LiFePO4的循环充放电曲线图......................................................................253.5LiFePO4的循环性能.....................................................................................284LiFePO4的掺杂改性.............................................................................................284.1掺杂Al3+离子的LiFePO4的合成...............................................................294.2样品的X射线衍射分析（XRD）.............................................................304.3LiFe1-xAxPO4的伏安曲线..............................................................................314.4充放电测试...................................................................................................32结论............................................................................................................................33致谢..........................................................................................................................34参考文献......................................................................................................................351锂离子电池正极材料LiFePO4的合成摘要：化石燃料引发的能源和环境危机迫使人类着眼于清洁、可持续利用的太阳能、风能等新能源。这些能源的间歇性必然对能源储存系统提出更高要求，锂离子电池被视为最有效的电化学储能系统之一。能源短缺和环保要求促进了锂离子电池的发展，橄榄石型LiFePO4具有较高的理论比容量、工作电压高、原料成本低、材料无污染、循环性能优良、热稳定性好等优点，从而被认为是最具开发前景的新一代锂离子电池正极材料。但是，LiFePO4材料非常低的电子电导率成为了其进一步应用的障碍。目前研究的改进途径主要有3种：(1)合成粒径小、形貌规则均匀的材料；(2)在材料颗粒间添加碳、金属粉末等导电物质；(3)掺杂金属离子，从晶格上改善材料的性能。其中，对LiFePO4材料进行掺碳改性是最常见、最具实效的方法。本论文研究了合成LiFePO4的方法并对其进行改性：采用葡萄糖、蔗糖、柠檬酸、PVC等作为碳源的碳热还原法合成LiFePO4，并系统地研究不同碳源的碳包覆和金属离子的体相掺杂对正极材料LiFePO4的结构和电化学性能的影响，从而寻找出提高LiFePO4的电子电导率和离子扩散速率的途径。结果表明，使用葡糖糖和PVC作为碳源制备出的LiFePO4颗粒更细小，分布更均匀，电容量更大，并且具有良好的循环稳定性能。而金属离子的掺杂需在一定范围内进行，才可提高材料的电化学性能。关键词：锂离子电池，正极材料，磷酸铁锂，掺杂2Abstract:Energyandenvironmentalcrisiscausedbyfossilfuelmakespeopleseekclean,sustainableenergy,suchassolarenergyandwindenergy.Theintermittentofthisenergycallforhigherrequirementsofenergystoragesystem.Lithiumionbatteryisregardedasoneofthemosteffectiveelectrochemicalenergystoragesystem.TheproblemofEnergyshortageandtheprotectionofenvironmentarepromotingthedevelopmentoflithium-ionbatteries.Olivine-typeLiFePO4isconsideredasthemostpromisingcandidateforthenext-generationcathodematerialsofLi-ionbatteries．Itpresentsmanyadvantages，suchashightheoreticalspecificcapacity，highvoltage，lowcostofrawmaterials，environment-friendly，goodcycleperformanceandthermalstability.However,thelowconductivityofLiFePO4haslimiteditsfurtherapplicationgreatly.Atpresent,theresearchofimprovementhavethreemainways:(1)SynthesisSmallparticlesizeandregularmorphologyandhomogeneousmaterial;(2)Additioncarbon、metalpowderandotherconductivematerialsintheparticulatematerials;(3)Dopingmetalions,improvetheperformanceofmaterialsonthelat