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为改善尖晶石LiMn2O4的循环性能,采用高温固相法合成了由Li2CO3改性的尖晶石锂锰氧化物,研究了Li2CO3添加量对LiMn2O4性能的影响。通过XRD,Rietveld精细XRD分析和模拟电池等方法对产物的结构和电化学性能进行了表征与测试。结果表明,部分Li进入到尖晶石LiMn2O4的晶格中,增强了材料充放电循环过程中的结构稳定性。随着Li2CO3量的增加,产物的循环稳定性增加。当Li2CO3的加入量为0.06摩尔比时,10次循环后的高温容量衰减由改性前的15%降低到6.8%。 相似文献
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以LiCO3、V2O5、NH4H2PO4为原料,采用碳热还原法合成锂离子电池正极材料Li3V2(PO4)3(LVP).根据TG分析得到制备样品的温度范围.对所得材料分别进行了XRD、粉末微电极循环伏安及恒电流充放电测试.XRD分析表明, 850 ℃煅烧所得样品特征衍射峰型尖锐,晶体结构发育良好,为纯相的Li3V2(PO4)3;循环伏安测试表明,锂离子脱嵌分三步进行,循环伏安曲线对称性好;合成的正极材料在7 mA/g恒流充放电,首次充、放电比容量分别为129.8 mA·h/g、116.8 mA·h/g,充放电效率达90%,循环性能有待提高.材料中过量碳的加入提高了其充、放电比容量,使其循环性能有所改善. 相似文献
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λ-MnO2的结构与电性能研究 总被引:3,自引:0,他引:3
采用酸处理LiMn2O4的方法来制备λ-MnO2,并用X-射线衍射(XRD)、扫描电子显微镜(SEM)和恒电流充放电测试等方法对所得λ-MnO2的结构和电性能进行了研究。研究结果表明,所得λ-MnO2具有尖晶石型结构,晶粒细小,形貌较规则,粒径分布均匀;以其为正极组装成Li/MnO2电池的放电比容量达到226mAh/g。 相似文献
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尖晶石LiMn2O4表面包覆氧化钴的研究 总被引:1,自引:0,他引:1
采用高温固相法合成尖晶石LiMn2O4,并以化学沉积方式对其进行包覆氧化钴的表面处理。通过X射线衍射(XRD)、扫描电镜(SEM)等技术对表面处理前后的LiMn2O4进行表征,分析了表面处理后LiMn2O4物理特性的变化,并结合电化学性能测试,研究了表面处理及其工艺和条件对LiMn2O4电化学容量与循环性能的影响。结果表明,表面处理后LiMn2O4循环性能显著提高。随氧化物含量的增加,循环性能提高,容量降低。未经表面包覆的LiMn2O4首次充放电容量为108.13mAh/g,50次循环充放电后容量衰减26.3%。500℃加热处理的表面包覆0.5%、2%氧化钴的LiMn2O4首次循环放电容量各为118.38mAh/g、115mAh/g,经过50次充放电循环后,容量分别降低8%、7%。 相似文献
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为了改善锌空气电池空气扩散电极的氧还原电催化性能,提高电池的放电电流密度,采用溶胶凝胶法合成了纳米级尖晶石型LiMn1.5Co0.5O4电催化剂。用傅立叶红外光谱(FTIR)、热分析(TG—DSC)、X射线衍射(XRD)对干凝胶和合成产物进行了分析表征,稳态电流一电压极化曲线测试LiMn1.5Co0.5O4作为空气扩散电极电催化剂的电催化性能。测试结果表明,所制得的干凝胶具有立体凝胶网络结构;当热处理温度为550℃时,所合成LiMn1.5Co0.5O4电催化剂具有完美的尖晶石型晶体结构,并且电催化活性最高。 相似文献
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<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 相似文献
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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, 相似文献
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《China Nonferrous Metals Monthly》2014,(10)
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 相似文献
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《China Nonferrous Metals Monthly》2014,(10)
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 相似文献
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《China Nonferrous Metals Monthly》2014,(10)
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, 相似文献
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《China Nonferrous Metals Monthly》2014,(12)
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. 相似文献
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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. 相似文献
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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. 相似文献