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《应用化工》2015,(5)
以商业活性炭为载体,通过硝酸表面改性活性炭,引入含氧官能团,为棒状二氧化锰(MnO2)和活性炭的结合提供桥梁。采用化学沉淀法在炭表面反应生成纳米结构的棒状二氧化锰,制备二氧化锰/改性活性炭(MnO2/OAC)复合电极材料。采用扫描电镜(SEM)、X射线衍射(XRD)对其结构进行表征;采用循环伏安法、恒流充放电对其电化学性能进行研究。结果表明,生成的MnO2均匀地负载在碳的表面,颗粒的直径在20~50nm;在1mol/L的Na2SO4电解液中,MnO2/OAC6复合电极材料体现了极佳的比电容,达到369.7F/g。材料优异的电化学性能归功于活性炭发达的孔隙结构和MnO2提供的法拉第电容。 相似文献
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《应用化工》2022,(5)
以商业活性炭为载体,通过硝酸表面改性活性炭,引入含氧官能团,为棒状二氧化锰(MnO2)和活性炭的结合提供桥梁。采用化学沉淀法在炭表面反应生成纳米结构的棒状二氧化锰,制备二氧化锰/改性活性炭(MnO2/OAC)复合电极材料。采用扫描电镜(SEM)、X射线衍射(XRD)对其结构进行表征;采用循环伏安法、恒流充放电对其电化学性能进行研究。结果表明,生成的MnO2均匀地负载在碳的表面,颗粒的直径在2050nm;在1mol/L的Na2SO4电解液中,MnO2/OAC6复合电极材料体现了极佳的比电容,达到369.7F/g。材料优异的电化学性能归功于活性炭发达的孔隙结构和MnO2提供的法拉第电容。 相似文献
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通过常见添加剂MgO,Y2O3,TiO2,MnO2及CAS(CaO-A12O3-SiO2玻璃)等对纳米α-Al2O3助烧性能的比较,选出以TiO2,CAS及MnO2为代表的三元添加剂进行单纯形格子设计及回归分析.结果表明:复合添加剂TiO2-CAS-MnO2的比例对样品致密化及显微结构有着显著的影响.TiO2,CAS及MnO2按一定比例引入到纳米α-Al2O3可实现最大致密化速率,却易引起晶体的异常长大和异向生长;而仅CAS与MnO2按一定比例引入比单一添加CAS或MnO2更能促进纳米α-Al2O3的烧结,样品平均晶粒尺寸约为3μm,且分布均匀,几乎无晶粒异常生长现象. 相似文献
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无机纳米粒子填充改性聚四氟乙烯复合材料的研究 总被引:8,自引:0,他引:8
研究了无机纳米粒子在聚四氟乙烯(PTFE)材料中的分散方法,以及纳米Al2O3、纳米SiO2的填充改性对PTFE复合材料力学性能和耐磨性能的影响。结果表明:机械混合和气流粉碎的组合方式可使无机纳米粒子在PTFE中得到均匀分散;用量0。3%的纳米Al2O3提高了PTFE材料的拉伸强度和断裂伸长率,用量3%的纳米SiO2显著改善了PTFE材料的耐磨耗性能;纳米Al2O3和纳米SiO2协同改性PTFE,获得了拉伸强度27.4MPa、断裂伸长率306.7%、邵D硬度60.0、磨耗量0.001g和摩擦系数0.20的综合性能优异的改性PTFE耐磨耗材料,该改性PTFE材料适用于汽车发动机曲轴油密封件的制备。 相似文献
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本文用正交试验法研究了添加剂TiO2、MnO2、SiO2,N2O5以及烧结温度对Sr-Ti-Bi系高压陶瓷电容器材料介电性能的影响。正交试验的结果表明:最佳添加量分别是TiO2为0.3%,MnO2为0.05%,SiO2为0.2%,NbO2为0.2%,烧结温度为1250℃。 相似文献
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Deyang Qu 《Journal of Applied Electrochemistry》1999,29(4):511-520
The feasibility of using a manganese dioxide cathode with a metal hydride anode is discussed. MnO2 cathodes doped with bismuth compounds were rechargeable. The cathode material was prepared in its discharged state from MnO and bismuth compounds, thus matching the metal hydride anode in terms of initial state of charge, formation cycles and balance of self-discharge. It is believed that the presence of bismuth in the cathode prevents formation of spinel manganese oxide and lowers the activation energy (overpotential) for the second electron reduction and oxidation of MnO2. Hydrogen recombination with MnO2 was also studied to enable balancing of the self discharge rates of cathode and anode during storage. 相似文献
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采用固相烧结法成功合成了Rh掺杂的LiNi0.5Mnl.504正极材料。通过XRD测试和充放电测试表征了材料的晶体结构和电化学性能。结果表明Rh掺杂可以有效提高LiNi05Mnl504在大电流密度(5c和10c)条件下的放电电量,并可以显著改善IOC充放电条件下的循环性能。 相似文献
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以乙醇胺醋酸盐作为反应介质,采用硫酸铬、一水氢氧化锂和新制备二氧化锰为原料,在常压低温下采用离子热法和后续高温处理,制备了正极材料LiMn2O4及其掺杂改性物LiCr0.1Mn1.9O4。分别对材料的形貌和电化学性能进行XRD、SEM和充放电测试。SEM测试结果表明:LiMn2O4和LiCr0.1Mn1.9O4均为棒状结构,集中呈现为长宽分别为1.2 μm、200 nm。充放电测试表明:金属铬的掺杂能有效提高材料的循环性能,在0.1 C倍率下,材料 LiCr0.1Mn1.9O4首次放电比容量为123.6 mA·h/g,经历前10个循环的容量少量衰减后,其后的50次循环中容量基本不变。 相似文献
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采用固相烧结法合成了Nb掺杂的LiNi0.5Mn1.5O4正极材料.通过XRD测试和充放电测试表征了材料的晶体结构和电化学性能.结果表明Nb掺杂容易产生LiNbO3杂质,并影响其放电能力,少量Nb掺杂获得的LiNi0.425Nb0.03Mn1.5O4展示出良好的大电流放电性能. 相似文献
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Rather than depend on highly acidic or basic electrolytes, ionic liquids are used to create new types of solid state cells which mimic standard alkaline cells, but without the need for caustic electrolytes. Presented here is a non-aqueous approach to primary and secondary power sources, where the pure ionic liquid not only acts as the electrolyte/separator in both liquid and solid state batteries, but as a reactive species in the cell's electrochemical makeup. In this work, batteries are designed using standard cathode and anode materials such as MnO2/Carbon, PbO2, NiO, AgO and Zn. However, by using a solid polymer electrolyte composed of an ionic liquid and polyvinyl alcohol, novel types of solid state batteries are demonstrated with discharge voltages ranging up to 1.8 V, dependent upon the type of cathode and anode used. These batteries are characterized by ionic conductivity, initial voltage measurements, and discharge profiles. 相似文献
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采用固相反应法制备了 Li2FeSiO4-xSx/C (x=0,0.01,0.02,0.03)纳米正极材料。通过 X 射线 衍射(XRD)、扫描电子显微镜(SEM)、能量色散光谱仪(EDS)、X 射线光电子能谱(XPS)、拉 曼光谱(Raman)、红外吸收光谱(FTIR)及恒流充放电测试研究了材料的微观形貌、晶体结构和 电化学性能。结果表明,Li2FeSiO3.98S0.02/C 形貌呈纳米球状,平均粒径为45.38nm,纳米尺寸的粒径有利于缩短Li+的扩散途径;碳包覆抑制纳米晶粒的生长,可以增强材料的导电性;硫掺杂能扩大材料的隧道间距,加快了Li+的迁移速率。Li2FeSiO3.98S0.02/C 表现出较高的充放电比容量、优异的倍率性能以及循环稳定性,在 0.1C 下首次放电比容量高达 180.1mAhg -1,在 10C 下放电比容量为 85mAhg-1,1C 下循环 100 次后的容量保持率为 91.3%。 相似文献
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The K2FeO4/TiB2 battery has a significant advantage of battery capacity due to their multi-electron discharge reaction both of the cathode K2FeO4 (3e−) and the anode TiB2 (6e−). However, the more positive reduction potential of TiB2 anode results in a lower discharge voltage plateau of K2FeO4/TiB2 battery, compared with the K2FeO4/Zn battery. The simple modification of Fe(VI) cathode with CuO additive was used to improve the cathode reduction kinetics and decrease the polarization potential in the discharge process. Another electrocatalysis media RuO2 with excellent electric conductivity is used as additive in K2FeO4 cathode to demonstrate which effect is more important for the discharge voltage plateau, electrocatalysis or electron conductivity of additives. The results show that the 5% CuO additive modified K2FeO4/TiB2 battery exhibits an enhanced discharge voltage plateau (1.5 V) and a higher cathode specific capacity (327 mAh/g). The advanced discharge voltage plateau can be due to the electrocatalysis of additives on the electrochemical reduction kinetics of Fe(VI) cathode in the whole discharge process, rather than the good electronic conductivity of additives. 相似文献