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SnO2对尖晶石LiMn2O4电极材料的改性 总被引:1,自引:0,他引:1
为提高锂离子电池正极材料LiMn2O4在高温下的循环性能,以Sn(OCH2CH2OCH3)4为原料,采用溶胶-凝胶法在LiMn2O4表面包覆了一层稳定的二氧化锡层. 用X射线粉末衍射和扫描电镜对包覆前后LiMn2O4的结构进行了表征. 结果表明,二氧化锡包覆层的存在减少了LiMn2O4与电解液的直接接触,有效地抑制了高温下LiMn2O4与电解液的相互作用,减少了锰在电解质中的溶解;经表面修饰处理后,LiMn2O4正极材料的初始容量虽稍有下降,但高温下(60℃)的充放电循环稳定性能得到了显著提高,40次循环后的高温容量衰减由改性前的31%降低到12%,并且电池的自放电速率也显著减小. 作为锂离子电池的正极材料,该表面改性材料是众多取代LiCoO2材料中最具竞争力的材料之一,也有望成为锂离子动力电池的正极材料. 相似文献
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通过浸涂的方式,以具有小分子水磁化的纳米粉体乳液(EMT)为表面活性剂,对镁电池用负极材料进行表面改性,并采用XRD和SEM对合金表面的相组成及表面形貌进行了分析。以质量分数为3.5%的NaCl溶液作为电解质溶液,在室温下对经EMT修饰的镁负极进行了抗腐蚀实验,并采用Tafel曲线和电化学阻抗谱研究了不同镀膜次数对镁负极防腐性能的影响。结果表明,镀膜3、6、9次镁负极的腐蚀电流密度分别为106.8、90.7和89.0μA/cm~2,均低于未镀膜样品(283.8μA/cm~2),表现出较好的防腐蚀性能。EMT在材料表面形成的SEI膜能够在不影响材料相结构的前提下,有效抑制镁负极在海水中的腐蚀行为,且随着镀膜次数的增加其耐腐蚀性能增加。 相似文献
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1聚合物凝胶电解质的特征 在以前的非水电解液锂二次电池方面,正极和负极都能用聚偏氟乙烯(PVdF)作为粘结剂。最近对隔板也可用PVdF树脂(如表1所示)。全部一体化电池已被设计出来,面向实用化,正进行开发。在隔板方面可采用电解液溶胀的PVdF多孔膜和PVdF类树脂凝胶。同以前的类型不同,因为电解液包含在树脂中,不发生漏液,电池形状的自由度大,还可制成片状。 若将电池制成薄型,首要问题是如何让隔板介于正极与负极间且固定,即采用液体电解质的筒状电池在卷为筒状时,紧贴筒内,将正极,隔板(通常使用由聚乙烯… 相似文献
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K. Vuorilehto 《Journal of Applied Electrochemistry》2003,33(1):15-21
In this work an environmentally friendly water-activated battery was developed and investigated. The anode material was a magnesium alloy; the cathode consisted of manganese dioxide, potassium chloride and graphite. Battery characteristics were tested at room temperature and additionally in an atmospheric simulation chamber because water-activated batteries are mostly used in meteorological radiosondes. Voltage losses inside the battery were measured using a miniaturized reference electrode, and heat evolution of the battery was studied calorimetrically. The main source of voltage losses and heat was found to be the magnesium anode. Compared to the traditional Mg/CuCl batteries, there was little difference in voltage and capacity, but a significant difference in the environmental impact, as the Mg/MnO2 battery does not contain any heavy metal salts. 相似文献
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Performance characteristics of organic–inorganic composite electrodes in magnesium reserve batteries
Electrochemical characteristics of m-dinitrobenzene (m-DNB) based composite cathode materials involving compounds such as AgCl, TiO2, HgO and CuCl have been investigated and (Mg AZ31 alloy anode) as an activated battery system using 2 M magnesium perchlorate aqueous electrolyte. The concentration of the composites has been optimized so as to obtain high electrochemical
performance of Mg/m-DNB reserve batteries through constant current discharge studies. Mg/m-DNB cells containing 5-wt % of HgO when discharged at current density of 2.1 mA cm−2 delivered 5.3 Ah capacity corresponds to a columbic efficiency of 97% as compared to the cells without composite. 相似文献
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因兼顾成本低、安全性能好及体积能量密度高(3832 A·h·L-1)等优点,镁金属二次电池受到了广泛关注。但是,镁负极的实际应用仍然受限于电解液活性物种溶剂化结构的认识不足。目前,镁基电解液主要分为醚类溶剂的格氏试剂电解液、氯化镁铝络合物(MACC)电解液和Mg(TFSI)2基电解液等。其中,镁离子-氯离子的配位结构对镁电池正常运行起到了关键作用,主要突出在降低沉积过电位、增强镁沉积动力学和提高沉积镁可逆性等方面。以氯离子在体相电解液中和在电极界面上与镁之间的相互作用为切入点,分析了镁基电解液的前期开发路线及设计理念,并对镁二次电池的未来发展进行了总结和展望。 相似文献
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A stable magnesium battery has been developed based on a magnesium anode, a poly(dioxyethane thiophene) (PEDOT) cathode and a near-saturated aqueous solution of LiCl, MgCl2, or mixture of these salts at pH of 11. This combination leads to a low water activity in the electrolyte, which thus suppresses the hydrogen evolution reaction on Mg, as well as producing a stable oxy-hydroxide film which protects the metal surface from freely corroding. The conducting polymer cathode is reduced somewhat during the discharge process, however, appears to be readily re-oxidised (as determined from the resistance) by the oxygen present in the cell. The cell is therefore primarily a Mg/O2 battery, however, the PEDOT appears to enhance the performance, in particular the discharge voltage. 相似文献
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采用溶胶-凝胶法制备得到了主相为四方结构的MgMn2O4。研究了煅烧温度对产物的相演化和表面形貌的影响,比较了电化学循环稳定性。结果表明,550℃烧结得到了表面呈现多孔通道和孔洞的MgMn2O4 (MMO550),在40 mA/g电流密度下,最大放电比容量为54.0 mAh/g; 与碳纳米管于400℃复合2 h后,CNT形成的导电网格有效地将MgMn2O4颗粒连接起来,得到MMO/CNT样品的首次放电比容量可达118.0 mAh/g,是未复合MMO550最大放电比容量的2.2倍,循环30周后容量保持在88.1 mAh/g。 相似文献
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A novel type of magnesium-air primary cell has been evolved which employs non-polluting and abundantly available materials. The cell is based on the scheme Mg/Mg(NO3)2, NaNO2, H2O/O2(C). The magnesium anode utilization is about 90% at a current density of 20 mA cm–2. The anode has been shown to exhibit a low open-circuit corrosion, a relatively uniform pattern of corrosion and a low negative difference effect in the electrolyte developed above as compared to the conventional halide or perchlorate electrolytes. In the usual air-depolarized mode of operation, the cell has been found to be capable of continuous discharge over several months at a constant cell voltage of about 1 V and a current density of 1 mA cm–2 at the cathode. The long service-life capability arises from the formation of a protective film on the porous carbon cathode and fast sedimentation of the anodic product (magnesium hydroxide) in the electrolyte. The cell has a shelf-life in the activated state of about a year due to the low open-circuit corrosion of the anode. These favourable features suggest the practical feasibility of developing economical, long-life, non-reserve magnesium-air cells for diverse applications using magnesium anodes with a high surface area and porous carbon-air electrodes. 相似文献
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阐述了钾离子电池关键材料和电池技术的研究现状,特别是对普鲁士蓝类和P2、P3相层状氧化物材料作为正极材料的电化学性能及存在的问题、碳基负极材料(石墨、硬碳、软碳等)的电化学性能及钾离子脱嵌机理、当前所用电解液的优缺点等方面都进行了较为全面的讨论和分析。分析表明普鲁士蓝和非石墨材料等材料已经同时展示出较高的比容量和循环性能,而对于层状氧化物材料和石墨材料,钾离子的电化学嵌入/脱出伴随显著的体积变化和复杂的相变,同时与正负极材料具有高度相容性的电解液尚未获得。指出钾离子电池需要进一步发展其电极材料和电解液。 相似文献