【作者】 杨海波；

【导师】 梁辉；

【作者基本信息】 天津大学 ， 材料学， 2006， 硕士

【摘要】 研究了湿化学法从废旧锂离子电池回收正极活性材料中有用金属的工艺。NMP可以使正极活性材料从铝箔上完全脱落,在H₂SO₄与双氧水系统中,钴和锂的回收率分别为95.06%和84.02%。研究了共沉淀法制备Li₂CO₃与CoCO₃前驱体最佳工艺条件,探讨了热处理对煅烧产品晶体结构的影响。煅烧产物经XRD分析,750℃具有典型的六方对称性,空间群为R3m的一种结构。并通过BET测试,LiCoO₂粉体具有较大的比表面积,达18.55m2g^-1;通过扫描电镜观测到平均粒径在70nm左右;具有良好的电化学性能,首次充电容量达146mA.h·g^-1,首次放电容量达142mAh·g^-1。以从废旧锂离子电池中回收的钴锂盐为原料,NH3·H2O和NH4HCO3为沉淀剂,聚乙二醇为分散剂,获得一种Li₂CO₃为壳﹑CoOHNO3为核的壳核结构混合沉淀物。用XRD对煅烧产品进行了晶相分析,通过红外和拉曼光谱分析确定LiCoO₂为R-3m空间群的六方层状结构,随温度的升高,层状属性增强。用BET分析了700℃合成的LiCoO₂的粉体比表面积,其值为达7.949m2g^-1,并通过SEM观察到其颗粒形貌和粒径大小（小于0.2μm）,并且随烧结温度的升高,生成的晶体颗粒有所增大。观察到湿化学法合成的材料粒径比固相反应制得的材料粒度要小得多。包覆沉淀法合成的LiCoO₂具有优良电化学性能。研究了草酸沉淀钴和锂工艺,重点讨论了不同工艺条件对草酸钴和草酸锂颗粒形貌和大小的影响。结果表明,在液相方式加入草酸条件下,所得草酸沉淀物为块状,棒状,纤维状或针状;草酸以固体形式直接加入时,有利于球形或类球形颗粒的形成。外形为沿轴向生长的前躯体煅烧产物均表现出各向同性,生成的产物具有光滑的表面以及较窄的粒径分布区间,且均为单个的类球状或六方外形颗粒;然而,前躯体外形为球状的煅烧产物为粒径分布窄小的球状颗粒。更多还原

【Abstract】 The process of reclaiming valuable metals in positive active materials from spent lithium ion batteries was studied. NMP leaching rate of wastes reaches 100%. The recovery rates of cobalt and lithium get up to 95.06% and 84.02% using mixture solution including sulfuric acid and hydrogen peroxide. respectively.The optimal technological conditions of preparing precursor by co-precipitation process were investigated. The effects of heat-treating on crystal structure of calcined samples were studied. The XRD result shows that the powders prepared at 750℃is the mono-phase crystal structure and well- crystallized in the hexagonal system with space group R-3m. The specific areas of LiCoO₂ powders calcined at 750℃reach 18.55m²/g by BET technique. The average particle size of powder （about 70nm） is observed by SEM. LiCoO₂ prepared at 750℃exhibits excellent performances in term of its high first charge capacity (146 mAh·g^-1) and discharge capacity (142 mAh·g^-1).A sort of composite precipitates in a core-shell form, where the CoOHNO3 was the core and Li₂CO₃ was the shell, were prepared with NH3·H2O and NH4HCO3 as precipitator and PEG as dispersant in the solution with an aqueous nitrate solution containing cobalt ions and lithium ions from spent lithium ion batteries as raw materials The crystal structure of calcined powder was investigated by XRD.LiCoO₂ is layered structure in the hexagonal system with space group R-3m by IR and Raman spectrum analysis. The result shows that layered attribution strengths with baking temperature increasing. The specific surface area (about 7.949m2g^-1) of the powder was measured by BET method. The particles configuration & the average particle size （ lower 0.2μm） of the LiCoO₂ powder were observed by SEM and the grain size increases with temperature. The size of particles prepared by更多还原