锂离子电池中高容量Si-Cu/C复合负极材料的制备与性能研究

采用高能球磨方法制备了用作锂离子电池负极材料的Si—Cu／C复合材料。X射线衍射和扫描电子显微镜结果表明，复合材料中Si和Cu5Si是共存的，活性硅颗粒均匀地分散在石墨和惰性的铜硅合金基体中。电化学测试在电流密度0．2mA·cm^-2，电压范围0—1．4V条件下进行，其结果表明高分散Si—Cu／C复合材料首次可逆容量为524mAh·g^-1，远高于目前普遍使用的中间相碳微球；循环寿命也远优于同粒度的硅单体，经过30次循环后容量仍保持531mAh·g^-1。其高比容量和良好的循环性能表明：高分散Si—Cu／C复合材料有望替代碳成为锂离子电池负极材料。     

锂离子电池钴酸锂材料的改性及应用

锂离子电池钴酸锂正极材料经改性后 ,首次放电比容量和效率可达 15 0mAh·g- 1 和 95 .8%,在 0 63 0 48电池中的应用 ,具有较好的工艺适应性 ,电池容量可达 774mAh·g- 1 ,首次放电平台可达 89%,循环 3 0 0次容量保持 87%,平台尚有 83 .7%。而且具有较好的高低温、荷电保持能力和安全性能。电化学性能接近日本A级钴酸锂材料     

固相法制备LiNi0.25Co0.5Mn0.25O2正极材料的研究

以LiOH·H2O和Ni，Co，Mn过渡金属或其氧化物为原料，采用固相法制备了锂离子电池正极材料LiNi0．25Co0．5Mn0．25O2。对产物进行了XRD，SEM及电化学性能等测试。结果表明：过渡金属原料对所得产物性能的影响很大，在其他原料相同的情况下，以金属Mn为原料所得产物相比以MnO2为原料所得产物具有结晶程度更加完整、颗粒尺寸更大、振实密度更高、电化学性能更好等特点；以金属Ni，Co，Mn为原料所得产物的不可逆容量较低、首次放电比容量可达171．6mAh·g^-1，振实密度高达2．87g·cm^-1。     

低钴AB5型贮氢合金的制备与研究

用均匀设计试验方法设计系列含Fe低Co AB5型贮氢合金B侧配比, 以放电容量、活化次数、容量保持率及放电平台中值电位为多目标函数, 采用逐步回归分析方法和最小二乘法及黄金分割一维寻优手段进行最优化处理, 确定了最优化的B侧合金元素的摩尔比 Mm0.8La0.2Ni4.0Mn0.5Al0.3Co0.37Fe0.13(AB5.3).新型含Fe低Co MmB5型贮氢合金是单相CaCu5型结构, Co含量为4.97%, 放电容量达307.3 mAh·g-1(极片), 活化次数为两次, 500次循环后容量保持率为78.9%, 高温容量为277.2 mAh·g-1(55 ℃), 低温容量为197.3 mAh·g-1(-30 ℃), 3C放电容量为275.4 mAh·g-1.     

过渡金属氧化物Co3O4的嵌锂性能及其改性

采用机械球磨制备了一定粒度的锂离子电池负极材料Co3O4 。电化学性能测试结果表明Co3O4 首次嵌锂容量为 990mAh·g- 1 ,脱锂容量为 3 95mAh·g- 1 。通过添加石墨类材料对Co3O4 进行了改性研究。充放电测试表明 :通过长时间机械混合球磨处理后的一定粒度的改性材料首次脱锂容量可提高到 63 2mAh·g- 1 ,充放电循环 15周后 ,容量保持在 40 8mAh·g- 1 ,电化学性能优于单纯的Co3O4 。由此可见通过添加石墨类材料并进行机械球磨以改变材料的微观结构不仅可以提高材料Co3O4 的可逆容量 ,而且改善了其循环寿命。     

镍氢电池负极用纳米晶稀土贮氢合金的性能研究

对采用双辊快淬法制备的纳米晶稀土贮氢合金Ml(NiCoMnAl) 5相结构、贮氢性能和电化学充放电性能进行了研究分析。X射线衍射分析 (XRD)结果表明 ,合金片由均匀的CaCu5相组成 ,其晶粒尺寸平均为 2 0～ 40nm。PCT测试表明 ,该合金具有很好的平台特性和较小的滞后效应。将合金粉压成极片组装成模拟电池以 3 0 0mA·g- 1 (1C)电流充电 ,分别以 2 0 0 0mA·g- 1 (7C)和 3 0 0 0mA·g- 1 (10C)电流放电至 0 .9V和 0 .8V ,其电化学容量分别达到 2 5 0和 2 3 0mAh·g - 1。在 7C放电情况下 ,经 45 0循环后 ,容量衰减率小于 2 0 %。     

微波法制备锂离子电池正极材料LiFePO4的研究

采用微波法制备锂离子电池正极材料LiFePO4，通过X射线衍射（XRD）、扫描电镜（SEM）、循环伏安和恒电流充放电测试等方法对材料的结构、表观形貌及电化学性能进行表征，考察了葡萄糖、导电碳黑等不同碳源对目标材料性能的影响。结果表明，采用微波法能快速简便地制备出均相LiFePO4；于0．1C倍率下，以葡萄糖作为碳源的正极材料首次放电比容量可达131．1mA·h／g，充放电30次循环后，容量损失率为2．1％；以导电炭黑作为碳源的正极材料首次放电比容量为118．3mA·h／g，充放电30次循环后，容量损失率为5．2％。     

包覆型锂离子正极材料LiNi0.9Mn0.03Co0.07O2的合成与性能

采用复合包覆法合成了锂离子正极材料LiNi0.9Mn0.03Co0.07O2,前驱体的合成过程条件与最终包覆的材料性能有关。讨论了包覆沉淀反应过程中沉淀剂、pH值、搅拌速度和氨水浓度对电化学性能的影响。同时还考察了煅烧制度对材料电化学性能的影响。结果表明：在优化条件下Co,Mn均匀包覆在β-Ni（OH）2表面上;合成的正极材料LiNi0.9Mn0.03Co0.07O2在电压范围3～4.3V,电流密度30mA·g^-1下,第二次放电容量为194mAh·g^-1,50次循环后容量仍保持为189mAh·g^-1,材料循环性能稳定。     

一步水热法合成3D花状CoS锂离子电池负极材料的组织及电化学性能研究

以CoCl2·6H2O和硫脲(CH4N2S)为原料,采用一步水热法,通过改变钴硫摩尔比和添加表面活性剂制备出两种不同形貌(3D花状和球状)的硫化钴(CoS)锂离子电池负极材料。结果表明,当钴硫摩尔比为1:1时,在180℃下水热反应12 h可得到3D花状CoS负极材料,其三维立体花状结构由纳米级层片组成;当钴硫摩尔配比为1:1,添加十六烷基三甲基溴化铵(CTAB),在180℃下反应12 h可制得由小颗粒聚结成的球状CoS负极材料。在0.1C电流密度下,3D花状CoS电池首次放电比容量为752m Ah·g^-1,并且具有良好的倍率性能;在1C电流密度下,经过200圈的循环测试后,3D花状CoS电池仍有较高的放电比容量(185 mAh·g^-1),远高于球状CoS电池(118.6 mAh·g^-1),并且没有衰减的趋势。     

静电纺丝法制备钴酸镍及其电化学性能试验研究

研究了采用静电纺丝法制备NiCo₂O₄纳米纤维前驱体，并将煅烧后的NiCo₂O₄纤维用作锂离子电池负极材料，考察了其电化学性能。结果表明：质量比2∶1的Co(NO₃)₂和Ni(NO₃)₂经电纺可制备出直径约400 nm的NiCo₂O₄纳米纤维前驱体；以NiCo₂O₄纤维作负极材料的锂离子电池首次放电比容量为1 141 mAh/g, 100次循环后放电比容量约为415 mAh/g;电池内部成分电阻仅为3.77Ω,循环性能稳定。     

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.