Li4Ti5O12的合成及其在锂离子电池中的应用

采用固相法合成了Li4Ti5O12材料.用XRD表征了材料的结构特征.用循环伏安、电化学阻抗和恒电流充放电考察了LiCoO2-Li4TiO12体系的电化学性能.结果表明,当电流密度为0.1mA/cm2 时.该体系下的首次放电比容量为122.2mAh·g-1,经过100次循环之后,比容量保持在112.9mAh·g-1.当电流密度为0.2mA/cm2时,50次循环后容量衰减仅为5.3%.实验证明,该体系下的电化学性能比较稳定.是一种比较有潜力的锂离子电池体系.     

熔炼法制备的AB5-AB2复合合金的晶体结构和电化学性能

选择AB2 型Laves相合金Zr0 .9Ti0 .1 (Mn0 .35Ni0 .55V0 .1 5) 2 作为添加剂与稀土基AB5型合金进行熔炼处理 ,制备了AB5 AB2 复合合金。XRD表明 ,制备的AB5 AB2 复合合金具有AB5合金的CaCu5主相结构 ,同时含有少量的AB2 合金的C14型Laves相存在。并且 ,随着AB2 含量的增加 ,复合合金中的第二相含量逐渐增加。通过复合处理 ,AB5合金的放电容量、循环寿命和倍率放电性能均得到明显提高。AB5 x ?2 复合合金电极的最大放电容量由x =0时的 3 2 2mAh·g- 1 升高到x =1时的 3 3 1mAh·g- 1 。AB5 1?2 复合合金电极 ,在 15 0 0mA·g- 1电流密度下的放电容量从 62mAh·g- 1 提高到 185mAh·g- 1 ,经 3 0 0次充 /放电循环后的容量保持率从 44 .2 4%提高到 78.5 1%。     

钠电正极材料Na2/3Ni1/3Mn2/3O2的合成工艺参数研究

通过高温固相法制备了钠离子电池正极材料Na2/3Ni1/3Mn2/3O2,并对Na2/3Ni1/3Mn2/3O2的合成工艺参数进行了研究.通过对不同条件下制得的正极材料进行物化性质与电化学性能的表征,确定材料的最佳合成温度为900℃,最佳保温时间为12 h.在2～4.5 V电压区间内,0.2 C倍率下,材料首周的放电容量为110 mAh·g-1,100周充放电后的可逆容量为86 mAh·g-1,容量保持率达78.1％.     

喷雾干燥法合成锂离子电池复合正极材料xLiFePO4.yLi3V2(PO4)3及性能研究

采用喷雾干燥和高温固相法合成了一系列xLiFePO4·yLi3 V2( PO4)3复合正极材料.电化学测试结果表明,0.95LiFePO4·0.05Li3 V2( PO4)3复合正极材料具有较高的比容量、优良的循环性能和倍率性能,在电压范围为2.0V～4.3V,0.1C,1C,5C条件下的放电容量分别为162.7,147.7和122.3 mAh·g-1.0.5LiFePO4·0.5Li3 V2(PO4)3和0.3LiFePO4·0.7Li3 V2 (PO4)3复合正极材料则表现出了良好的倍率性能,5C,10C充放电条件下容量保持率分别为:77％,73％,88％,82％.     

AB5-AB2复合合金电极的微观结构和活化性能

根据AB5型稀土基合金的活化性能优良及对氢化和氢化物分解过程具有催化作用的特点 ,将Zr0 .9Ti0 .1 (Mn0 .35Ni0 .6 5) 2 AB2 型Laves相合金与AB5型混合稀土合金进行机械球磨处理 ,制备了AB5 AB2 复合合金。研究了复合合金的微观结构和电化学性能 ,结果表明 :在AB5 AB2复合合金中 ,AB5粒子与AB2 粒子在表面处相互镶嵌在一起 ,并仍保持原来的晶体结构。复合合金电极的活化周期从AB2 合金的 11周减少到 4周 ,最大放电容量从 14 1mAh·g- 1 增加到 2 18mAh·g- 1 ,而且在活化初期表现出协同效应。     

超声辅助TiO2包覆尖晶石LiMn2O4及电化学性能研究

采用超声辅助溶液法在尖晶石LiMn2O4表面包覆TiO2.通过X射线衍射、扫描电子显微镜、恒电流充放电、交流阻抗技术分析合成材料的结构、形貌及电化学性能.结果表明:TiO2包覆LiMn2O4与LiMn2O4具有相似的X射线衍射结果,衍射峰尖锐,样品颗粒大小均匀,无明显团聚.室温下0.2C充放电时,表面包覆1％TiO2的LiMn2O4首次放电比容量为123.51 mAh·g-1,略低于未包覆LiMn2O4的124.02 mAh·g-1,但在2C和4C高倍率时,表面包覆1％TiO2的LiMn2O4比容量分别为105.54和80.73 mAh·g-1,远高于未包覆的79.76和66.37 mAh·g -1.室温及55℃下以0.2C倍率循环50后,表面包覆1％ TiO2的LiMn2O4容量保持率分别为91.69％和87.36％,远高于未包覆LiMn2O4的86.58％和78.02％.室温下以1C倍率循环100次后,表面包覆1％ TiO2的容量保持率比未包覆LiMn2O4高出3.75％.表面包覆TiO2后LiMn2O4的循环性能得到了大大的提高,尤其是高温循环性能.     

镧(Ⅲ)与锌(Ⅱ)复合掺杂非晶Ni(OH)2的电化学性能

采用微乳液快速冷冻共沉淀法制备镧(Ⅲ)与锌(Ⅱ)复合掺杂非晶态氢氧化镍粉体. 样品材料的结构形态和形貌采用XRD, SEM和Raman光谱进行表征分析, 同时将样品合成电极材料并组装成MH-Ni模拟电池, 研究了样品电极的不同掺杂量对其电化学性能的影响及其相应的作用机制. 实验结果发现, 在80 mA·g-1 恒电流充电5 h, 40 mA·g-1恒电流放电, 终止电压为1.0 V的充放电制度下, 复合掺杂4%La(Ⅲ)6%Zn(Ⅱ)样品的放电平台为1.273 V, 放电容量为346.86 mAh·g-1, 且电极材料在充放电过程中的稳定性和循环可逆性较好.     

镧取代对镁基贮氢合金的影响及其电化学性能研究

用机械球磨法(MA)合成了Mg0.9LaxAl0.1-xNi(x=0.015,0.02,0.025,0.03)系列合金。充放电性能测试表明金属Mg被La取代后,合金放电容量的衰减变缓,最高放电容量为418.64 mAh.g-1,30周以后仍能达到161.41 mAh.g-1。XRD结构分析表明,在球磨初期仍为晶态,随着球磨时间的增加,逐渐变为非晶态,此时放电容量达到最大。循环伏安和交流阻抗测试结果表明当La的取代含量为0.025时电化学容量最高,循环可逆性好且电极表面电子转移电阻即电化学反应电阻最小。     

非均匀沉淀法包覆合成LiNi0.9 Co0.07 Mn0.03O2锂离子正极材料

采用非均匀沉淀法包覆合成了LiNi0.9Co0.07Mn0.03O2锂离子正极材料.前驱体合成中各工艺条件与包覆材料的比表面积和电化学性能息息相关.试验研究了沉淀剂、搅拌速度、pH值和氨水浓度对包覆沉淀的影响及煅烧过程对材料电化学性能的影响.结果表明:在优化实验条件下Co/Mn复合包覆在β-Ni(OH)2表面上;正极LiNi0.9Co0.07Mn0.03O2首次放电容量为195mAh·g-1,50次循环后容量仍保持为188.6mAh·g-1.循环伏安研究表明:与LiNiO2相比,Co/Mn复合包覆合成正极材料LiNi0.9Co0.07Mn0.03O2的相变得到很好的抑制,材料显示出良好的循环性能.     

宽温型AB5储氢合金结构及其电化学性能研究

用高频感应熔炼法制备了Mm(NiCoAlMn)5储氢合金,采用模拟电池法测试了合金在238～323 K温度范围内的活化、放电容量和高倍率放电性能.结果表明:制备合金为典型AB5型储氢合金,303K温度条件下吸氢量达到1.38％(质量分数),氢化物生成焓为32.36 kJ ·mol-1H2.合金电极的活化性能、放电容量和高倍率性能受温度影响显著.室温预活化可有效改善电极的低温性能,经室温预活化后合金电极在238 K最大放电容量达到336 mAh·g -1,明显高于未经室温预活化的最大放电容量25 mAh·g-1.Mm(NiCoMn)5贮氢合金电极的高倍率性能随着温度的升高先升高后降低,273和303 K温度条件下合金保持高倍率性能良好,3C放电电流密度条件下容量保持率均高于80％;238 K温度条件下合金的大电流放电性能急剧降低,1C放电电流密度条件下容量保持率仅为10％; 273 K下合金电极的综合性能最佳,最大放电容量达到340 mAh·g-1,300 mA·g-1放电电流密度下的高倍率放电比率为86％.循环伏安法测试证实,在238～323 K范围内,电极的氧化峰峰值电流(Ip)与扫描速度的平方根(v1/2)之间均存在良好的线性关系,整个电极反应受氢原子扩散控制;随着温度的降低氢扩散系数急剧下降,从而导致该合金电极的低温高倍率放电性能变差.由Arrhenius公式计算出合金中的氢扩散活化能为10.56 kJ·mol -1.     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.