锂离子蓄电池正极材料制备方法的新进展

探讨了用于锂离子电池的常用正极材料、纳米正极材料和薄膜正极材料的制备方法,比较了不同制备方法的优缺点,并对纳米和薄膜正极材料的制备技术的发展进行了展望.     

LiCo_(1-X)M_XO_2的循环伏安性能研究

采用高温固相反应法制备了掺杂的锂离子电池正极材料LiCo1-XMXO2(M=Ni,Al,Mn,Bi,Zn;X=0.1,0.2),通过粉末微电极循环伏安法对制备的掺杂化合物进行了快速研究.结果表明:掺杂Al元素和Bi元素,能同时提高LiCoO2的充电和放电电压,而掺杂其他元素,均降低其充电电压而提高其放电电压.     

报废铅酸蓄电池的回收利用研究

从环境保护的角度研究了在报废蓄电池中回收利用PbO2 的方法 ,并试验加入PbO2 后对电池性能的影响 ,为提高电池性能 ,降低生产成本提供一个合理的方案     

LiMn2-2xCoxCrxO3.95F0.05正极材料的合成表征及表面包覆

采用溶胶-凝胶法合成了锂锰尖晶石正极材料LiMn2-2xCoxCrxO3.95F0.05(x=0.05、0.1),并用沉淀法在其表面包覆2%的TiO2.XRD和ESEM分析表明掺杂样品以及掺杂之后再包覆TiO2的样品依然保持尖晶石结构,样品颗粒大小分布都较均匀.电化学性能测试显示LiMn2O4的首次放电容量为124.4 mA.h/g,50次循环后容量损失43.2%,而多元掺杂样品LiMn1.9Co0.05Cr0.05O3.95F0.05和LiMn1.8Co0.1Cr0.1O3.95F0.05的初始放电容量分别为114.7和103.4 mA.h/g,100次循环后容量损失为9.7%和4.1%.LiMn1.9Co0.05Cr0.05O3.95F0.05包覆2%TiO2和LiMn1.8Co0.1Cr0.1O3.95F0.05包覆2%TiO2样品的初始放电容量为109.3和96.6 mA.h/g,100次循环后容量损失为5.0%和3.5%,经过改性后材料的循环性能得到改善.     

An electrochemical impedance spectroscopic study of the electronic and ionic transport properties of LiCoO2 cathode

The storage behavior and process of the first delithiation-lithiation of LiCoO2 cathode were investigated by electrochemical impedance spectroscopy(EIS). The electronic and ionic transport properties of LiCoO2 cathode along with variation of electrode potential were obtained in 1 mol·L?1 LiPF6-EC:DMC:DEC electrolyte solution. It was found that after 9 h storage of the LiCoO2 cathode in electrolyte solu-tions,a new arc appears in the medium frequency range in Nyquist plots of EIS,which increases with increasing the storage time. In the charge/discharge processes,the diameter of the new arc is reversi-bly changed with electrode potential. Such variation coincides well with the electrode potential de-pendence of electronic conductivity of the LiCoO2. Thus this new EIS feature is attributed to the change of electronic conductivity of LixCoO2 during storage of the LiCoO2 cathode in electrolyte solutions,as well as in processes of intercalation-deintercalationtion of lithium ions. It has been revealed that the reversible increase and decrease of the resistance of SEI film in charge-discharge processes can be also ascribed to the variation of electronic conductance of active materials of the LiCoO2 cathode.     

锂离子电池负极材料Li2MgSi的Li脱嵌性质研究

使用基于平面波展开的第一原理赝势法,研究了锂离子电池负极材料Li2MgSi在各种脱锂量下的锂脱嵌形成能、相应的体积变化、能带结构、电子态密度以及电荷密度分布.计算结果表明:脱锂量越大需要的能量越大,随脱锂量的变化,平均一个锂的脱嵌形成能在-1.21～-1.61 eV之间.脱锂过程中,体积先膨胀后收缩,整个过程中体积变化很大,是导致材料循环性能较差的重要原因.在脱锂过程中材料显示了由半导体性到金属性又到半导体性的特征.     

正极材料尖晶石LiMn2O4掺杂Ce6+的合成与性能研究

由高温固相法合成了锂离子电池正极材料尖晶石LiCexMn2-xO4(x=0～0.5),并经XRD和电化学等测试。实验结果表明,材料LiCe0.03Mn1.97O4在常温和高温下都具有较好的循环性能和电化学性能。     

Optimizing the Synthetic Conditions of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 from a Carbonate Co-precipitation Method

1 Introduction As a promising cathode material for lithium ion batteries,LiNi1/3Co1/3Mn1/3O2 attracted intensive attentions.Owing to high specific capacity,long circle life and excellent safety,it may be an alternative candidate for LiCoO2.As a complex composite,however,it is difficult to synthesize phase-pure LiNi1/3Co1/3Mn1/3O2 by a simple mixed calcination method[1].From this concern,carbonate co-precipitation method,which can prepare homogeneous LiNi1/3Co1/3Mn1/3O2 with typical layered structure,bec...     

用于测定废干电池中汞量的样品消解方法

考察了含汞固体废物样品的不同消解方法，指出采用加热挥发法消解会给测定结果带来很大误差，并提出了一种用于测定废干电池处理后残渣中汞含量的浓硝酸直接消解方法，该法快速、简便易行、化学试剂消耗少、并使后续测定的结果具有较高准确度。     

Comparative study of LiNiO2, LiNi0.8Co0.2O2 and LiNi0.75Al0.25O2 for lithium-ion batteries

The comparative study of LiNi0.8Co0.2O2 and LiNi0.75Al0.25O2 was carried out by X-ray diffraction (XRD) and electrochemical methods. The results show that Co and Al doping suppress the phase transition during charge-discharge. The experiments indicate that LiNi0.75Al0.25O2 has the better cycle-ability and over-charge resistance comparing with LiNi0.8Co0.2O2. The interfacial behavior was studied by use of electrochemical impedance spectroscopy (EIS). The results show that LiNi0.75Al0.25O2 has a slightly larger polarization character than LiNi0.8Co0.2O2.