浸渍条件对PEDOT型固体铝电解电容器容量引出率的影响

利用化学氧化法在电容器芯包中形成导电高分子固体阴极层,制备出固体铝电解电容器样品,考察了单体浓度、浸渍次数、氧化剂／单体浓度比例等浸渍条件对固体铝电解电容器容量引出率的影响。结果表明,在按理论化学计量比配置浸渍液的前提下,随着单体浓度和浸渍次数的增加,电容器的容量引出率呈递增趋势,最高达到标称容量的93．3％。氧化剂相对于单体的浓度比例对电容器的容量引出率有显著影响,随着氧化剂浓度的提高,电容器的容量引出率显著增加,当氧化剂相对于单体的摩尔比增加到略高于理论化学计量比,达到2．5：1时,电容器的容量引出率达到峰值,继续增大氧化剂的浓度,电容器的容量引出率下降。     

超级电容器用石墨烯极片的制备和性能

以石墨粉为原料,通过简便的氧化还原法制备了石墨烯。将石墨烯极片在有机电解液体系中组装成超级电容器。利用XRD、SEM对制备的石墨烯电极进行物相和形貌分析。采用恒电流充放电、循环伏安和交流阻抗对所制备超级电容器的电容性能进行了研究。结果表明,石墨烯电极超级电容器比天然石墨制备的超级电容器的比电容有了明显的提高;在电流密度为200mA/g,电压区间为1.25~2.5V下循环888次后比电容保持在45.5F/g,容量保持率在85.5%,表明石墨烯材料制备的电容器具有较好的充放电循环性能。     

超级电容器用石墨烯极片的制备和性能

以石墨粉为原料,通过简便的氧化还原法制备了石墨烯。将石墨烯极片在有机电解液体系中组装成超级电容器。利用XRD、SEM对制备的石墨烯电极进行物相和形貌分析。采用恒电流充放电、循环伏安和交流阻抗对所制备超级电容器的电容性能进行了研究。结果表明,石墨烯电极超级电容器比天然石墨制备的超级电容器的比电容有了明显的提高;在电流密度为200mA/g,电压区间为1.25~2.5V下循环888次后比电容保持在45.5F/g,容量保持率在85.5%,表明石墨烯材料制备的电容器具有较好的充放电循环性能。     

淀粉还原制备纳米MnO_2超级电容器电极材料

采用氧化交联淀粉还原高锰酸钾制备出了超级电容器纳米MnO2电极材料.通过XRD和SEM对电极材料进行了表征,采用电化学测试手段对电极材料在lmol/L Na2SO4溶液中的电容特性和比容量进行了分析.结果表明,采用该方法所制备的材料为无定型的(а-MnO2,颗粒尺寸在100～150nm左右;循环伏安和恒流充放电试验测试结果表明,а-MnO2电极具有良好的电容特性.在放电电流为100 mA/g时,其比容量高达158 F/g.     

MnO_2-CNTs复合材料的合成及其超级电容器性能研究

采用液相沉淀法在碳纳米管（CNTs）的表面沉积MnO2纳米颗粒,制得了MnO2-CNTs复合材料。通过扫描电子显微镜（SEM）、X射线衍射（XRD）对材料的微观结构及成分进行了表征。利用电化学循环伏安和恒电流充放电对材料进行电化学性能测试,表明MnO2-CNTs复合材料结合了MnO2较高的质量比电容和CNTs较好的电化学稳定性的优点,质量比电容为220F/g。并将MnO2-CNTs复合材料与活性炭（AC）组装形成非对称超级电容器,发现MnO2-CNTs与AC质量比为0.75：1时,质量比电容达到最高,为306F/g。非对称电容器性能较对称电容器有较大幅度的提高,并且具有良好的电化学稳定性。     

大豆分离蛋白膜基中性水相超级电容器的构筑EI北大核心CSCD

以三乙醇胺(TEA)为增塑剂,制备了一系列不同TEA含量的大豆分离蛋白(SPI)薄膜,并以改性SPI膜和商业膜为隔膜,以活性炭为电极材料,结合硫酸锂电解质,构筑了超级电容器单体器件,系统研究了各超级电容器的性能。研究结果表明,由改性SPI膜组装的超级电容器的电位窗口能够达到1.5V,且表现出优异的双电层电容特性。改性膜SPI/TEA-1.6组装的超级电容器EDLC-1.6有最高的单电极比电容,在1.0A/g电流密度下为113.44F/g,能量密度高达8.86(W·h)/kg,功率密度为7.84×10~2 W/kg,其电化学性能远优于由商业膜组装的超级电容器,且改性SPI薄膜具有良好的热稳定性及较好的离子传导性能。     

阴离子还原剂对超级电容器材料MnO2的物性及电容特性的影响

本文通过化学液相还原法采用不同的阴离子还原剂制备了超级电容器电极材料二氧化锰.实验表明,还原剂酸碱度的不同对产物表观颜色也有着明显影响.TEM表明所制备的MnO2均为棒状体,以NaHSO3还原所制备的样1分布最均匀,通过电化学测试比较,样1表现出更好的电容特性,在电位窗口0～1.0V、电流密度为5 mA·cm-2时,其首次放电比容值为255.59 F·g-1,在循环700次后比容值为242.57 F·g-1,容量损失仅5.12%.     

大豆分离蛋白膜基中性水相超级电容器的构筑

以三乙醇胺(TEA)为增塑剂,制备了一系列不同TEA含量的大豆分离蛋白(SPI)薄膜,并以改性SPI膜和商业膜为隔膜,以活性炭为电极材料,结合硫酸锂电解质,构筑了超级电容器单体器件,系统研究了各超级电容器的性能。研究结果表明,由改性SPI膜组装的超级电容器的电位窗口能够达到1.5V,且表现出优异的双电层电容特性。改性膜SPI/TEA-1.6组装的超级电容器EDLC-1.6有最高的单电极比电容,在1.0A/g电流密度下为113.44F/g,能量密度高达8.86(W·h)/kg,功率密度为7.84×10~2 W/kg,其电化学性能远优于由商业膜组装的超级电容器,且改性SPI薄膜具有良好的热稳定性及较好的离子传导性能。     

椰壳炭与MnO2复合电极双电层电容行为研究

采用自行制备的KMnO4热解产物MnO2（M）及其与市售高比表面积椰壳基活性炭（YK）复合分别作电极材料，以1和7mol／L KOH为电解液，分别组装戍双电层电容器，采用恒流充放电法、循环伏安测试法和交流阻抗法考察其电容性能，结果显示，当YK与M以质量比1：1混合均匀作电极材料时，其比容量和功率特性均显示最佳值，尤其在高浓度KOH溶液中性能更好，在电流密度为50mA／g时，比电容量达到309．6F／g，并且功率特性和循环性能良好。     

水热法制备MnO2的电容特性

采用水热法制备了超级电容器MnO2电极材料,以单因素实验确定了最佳的制备条件为:水热处理温度为120℃和反应时间为6h.XRD测试结果表明,所制得的MnO2是α-MnO2和r-MnO2的混合晶型.最佳制备条件下所制得的MnO2的比电容达168.39 F·g-1.为改善MnO2的倍率特性进行Al掺杂,XRD的测试结果表明,Al3 进入到MnO2的晶格中.电化学测试结果表明,掺Al改善了电极材料的倍率特性和循环稳定性.     

石墨烯负载花球状二氧化锰复合材料制备及其电容性能研究

利用高锰酸钾与乙醇之间的氧化还原反应,在多孔石墨烯表面沉积纳米二氧化锰花球,获得了一种新型的复合电极材料。通过XRD,TG,SEM,TEM等分析手段确定了材料的晶体结构、化学成分、微观形貌特征。电化学性能测试表明:纳米二氧化锰花球具有优异的比电容,但是倍率性能和循环性能不足。通过在石墨烯表面负载纳米二氧化锰花球,能够显著增加石墨烯的比电容,同时改善纳米二氧化锰花球的倍率性能和循环性能。采用0.5mol/L K_2SO_4电解液,进行三电极循环伏安测试,复合电极材料在2mV·s^-1扫速下的比电容高达295F·g^-1,在1000mV·s^-1扫速下,比电容仍然可达102F·g^-1,同时100mV·s^-1,1000次循环后,电容循环保持率可达96.3%。这表明石墨烯负载花球状二氧化锰材料是一种极具潜力的超级电容器电极材料。     

Bonding MnO2/Fe3O4 shell-core nanostructures to catalyze H2O2 degrading organic dyes

Shell-core nanostructures with both high catalytic activation and recyclability have been becoming hot property in nano-catalysis. By respectively using co-precipitation method, sol-gel method, and homogeneous precipitation method we manufactured shell-core nano-particles of Fe3O4 core and MnO2 shell. The Bonding mechanism of the composite is discussed in detail, and the efficiency and nature of the particles to degrade methyl orange by catalyzing H2O2 is also demonstrated. We show that by using homogeneous precipitation method one can obtain morphologically uniform nano-particles of about 5-6 nm MnO2 shell and 13-14 nm Fe3O4 core. The characteristic peak of Fe3O4 in the Infrared spectra of the composite particles was blue shifted, and a novel peak appears at 775.68 cm(-1) referring to occurrence of new bond. X-ray Photoelectron Spectroscopy analysis showed that the bonding energy of Fe2p and Ols was increased due to the combination of the MnO2 shell and the Fe3O4 core, suggesting a new bond of Fe-O-Mn occurred in the composite. The MnO2 shell has abundant hydroxyl radicals and exhibits high chemical activity in catalyzing H2O2 and degrading methyl orange with a degree of greater than 95%. On the other hand, the shell-core nanostructures are super-paramagnetic, and the saturated magnetization reaches 33.5 eum/g, which is sufficient for the catalyst to be recycled.     

Effect of Sintering on the Magnetism and Magnetoresistance of La1/3Nd1/3Ca1/3 MnO3

1. IntroductionThe colossal magnetoresistance(CMR) effect defined as cp/pH in perovskite-like La2/3Bal/3MnO3ferromagnetic film reaches 150% in room temperature and 5 T applied magnetic field[1]. The discoveries like this revived the transporting character research of magnetic oxide, especially the magnetoresistance effect in perovskite-like manganese oxide. In1994, Jin and others found[2] l.27x105% CMR inLal--.Ca.MnO3 film when temperature is 77 K andapplied magnetic field is 6 T. And …     

Hydrogen effect on refining of Mo metal by Ar-H2 plasma arc melting

The refining effect of Ar/Ar-H₂ plasma arc melting (PAM) was investigated and the purity of Mo metals was evaluated by glow discharge mass spectrometry (GDMS). Most impurities in the Mo metals except for W were removed by Ar/Ar-H₂ PAM down to a few mass ppm levels, and the purities of respective Mo metals refined by Ar/Ar-20%H₂ PAM were improved up to 4N(99.9943%) and 5N(99.9996%). It is also found that Ar-H₂ PAM provides excellent decarburization, deoxidation, and denitrogenization. This confirmed that the refining effect is chemically induced by activated hydrogen atoms during Ar-H₂ PAM.     

MnO_2/TiO_2复合物电极的制备及超级电容性能

采用水热法在阳极氧化的TiO_2纳米管阵列上修饰MnO_2,制备MnO_2/TiO_2复合物电极,并组装为对称超级电容器。利用FESEM、TEM、XPS和电化学工作站对样品的表面形貌、元素价态和电化学性能进行表征。结果表明:MnO_2以纳米颗粒形态均匀分布在TiO_2纳米管阵列管口和内部,充放电电流密度在1A/g下时,比电容为429.3F/g,经5 000次循环后的电容保持率为82.4%。MnO_2/TiO_2对称超级电容器在电流密度5A/g下充放电比电容为39.9F/g,经5 000次循环后的电容保持率为91.5%;功率密度400 W/kg下,能量密度为18.98 Wh/kg。阳极氧化的TiO_2纳米管阵列既可做MnO_2的载体,基底Ti又可做集流体,减轻了超级电容器的质量,为制备超级电容器提供了一种思路。     

智能包装系统用石墨烯基超级电容器的制备

目的 制备具有优异电化学性能的石墨烯/纳米纤维素/二氧化锰复合纤维水系超级电容器。方法 采用超声波分散处理制备氧化石墨烯/纳米纤维素/二氧化锰混合纺丝液;运用湿纺纺丝工艺制备氧化石墨烯/纳米纤维素/二氧化锰杂化纤维电极;通过氢碘酸还原和冷冻干燥处理构建具有多孔结构的石墨烯/纳 米纤维素/二氧化锰复合纤维电极;最后,将其组装成两电极水系超级电容器。结果 在石墨烯/纳米纤维素/二氧化锰复合纤维中,纳米纤维素的添加有效抑制了石墨烯片层的自聚集,并显著提升了复合纤维的亲水性和拉伸强度。二氧化锰的加入显著提升了纤维电极的电化学性能。得益于精心的实验设计,石墨烯/纳米纤维素/二氧化锰复合纤维的拉伸强度为338 MPa。组装后的水系超级电容器具有优异的电容性能和循环稳定性,在电流密度为0.1 mA/cm2时,面积电容为412.5 mF/cm2,循环1500次后,电容保持率为87%。结论 将切实可行的湿法纺丝策略与精心设计的电极结构相结合,制备的石墨烯/纳米纤维素/二氧化锰水系超级电容器为可穿戴便携式储能设备和智能包装能源供应系统的发展提供了良好的参考。     

复相烧结助剂中MnO2对α-Al2O3陶瓷支撑体性能的影响

采用挤压成型法和固态粒子烧结法制备α-Al2O3陶瓷支撑体,主要研究复相烧结助剂MgO-MnO2-TiO2中MnO2添加量(质量分数)对陶瓷支撑体性能的影响。通过压汞法、内外加压法、三点弯曲法、质量损失法、扫描电镜和X射线衍射等方法对α-Al2O3陶瓷支撑体的孔隙率、纯水通量、抗折强度、酸碱腐蚀、微观结构及晶体类型和晶相成分进行分析表征。研究结果表明:MnO2能够和Al2O3形成固溶体Mn2AlO4,使晶格畸化,增加晶体的结构缺陷,从而降低烧结温度,促进α-Al2O3陶瓷支撑体的烧结。当MnO2添加量少于0. 5%时,烧结不完全;MnO2添加量大于2%时,晶粒出现异常生长;MnO2的添加量为1. 5%时,制备的α-Al2O3陶瓷支撑体样品性能最佳,孔隙率为38. 25%,抗折强度为80. 3 MPa,纯水通量达6579. 52 L/(m2·h·MPa),酸/碱腐蚀重量损失率为1. 22%/0. 90%。     

Design and synthesis of MnO₂/Mn/MnO₂ sandwich-structured nanotube arrays with high supercapacitive performance for electrochemical energy storage

We demonstrate the design and fabrication of novel nanoarchitectures of MnO(2)/Mn/MnO(2) sandwich-like nanotube arrays for supercapacitors. The crystalline metal Mn layers in the MnO(2)/Mn/MnO(2) sandwich-like nanotubes uniquely serve as highly conductive cores to support the redox active two-double MnO(2) shells with a highly electrolytic accessible surface area and provide reliable electrical connections to MnO(2) shells. The maximum specific capacitances of 937 F/g at a scan rate of 5 mV/s by cyclic voltammetry (CV) and 955 F/g at a current density of 1.5 A/g by chronopotentiometry were achieved for the MnO(2)/Mn/MnO(2) sandwich-like nanotube arrays in solution of 1.0 M Na(2)SO(4). The hybrid MnO(2)/Mn/MnO(2) sandwich-like nanotube arrays exhibited an excellent rate capability with a high specific energy of 45 Wh/kg and specific power of 23 kW/kg and excellent long-term cycling stability (less 5% loss of the maximum specific capacitance after 3000 cycles). The high specific capacitance and charge-discharge rates offered by such MnO(2)/Mn/MnO(2) sandwich-like nanotube arrays make them promising candidates for supercapacitor electrodes, combining high-energy densities with high levels of power delivery.     

高性能双网络PAM/P123凝胶电解质的制备及其在二次Zn-MnO_(2)电池中的应用EI北大核心

柔性能量存储设备处于下一代电源的最前沿,其中最重要的组件之一就是凝胶电解质。采用自由基聚合法制备PAM/P123锌离子电池用双网络凝胶电解质,结果表明:加入少量三嵌段共聚物P123,宏观上提高凝胶电解质的抗拉强度、韧性和抗压强度,同时微观上使凝胶骨架形成0.6μm的中孔并提高表面孔分布密度,进而提高了电解液的浸润性。PAM/P123系列电解质不仅具有高平均溶胀率,而且在-30~65℃范围内电导率均高于纯PAM电解质。其中PAM/P123-2性能最佳,具有1920.79%平均溶胀率,且在0℃时的离子电导率为36.2 mS·cm^(-1)。使用该凝胶电解质制备的柔性准固态Zn/MnO_(2)电池在0℃下充放电稳定,1000周次循环后容量保持率达82.39%。     

Oxidative destruction of o-DCB on supported manganese oxide catalyst

An active catalyst, MnO(2)/Al(2)O(3), was prepared by a novel technique as well as wet impregnation method. Total oxidation of chlorinated aromatics on supported manganese oxide catalysts was investigated. It is seen that MnO(2) supported on Al(2)O(3) is an effective catalyst for the oxidative destruction of o-DCB in the concentration range of 1611-2263ppm at temperatures over 350 degrees C. It is also seen that for the catalyst with 0.029% MnO(2), the activity per unit amount of MnO(2) is much higher than that for the other catalysts and the activity per unit amount of MnO(2) decreases sharply for MnO(2)-loading above 0.5%. This high activity may be attributed to a high degree of dispersion of MnO(2) achieved by deposition from colloidal solution. No chlorinated byproducts are detected in the effluent during the oxidative destruction of o-DCB. It is proposed that catalyst with MnO(2)-loading less than 0.5% MnO(2) can be effective for the oxidative degradation of o-DCB. Such catalysts will be less difficult to dispose of after use in view of their low heavy-metal content, and consequently, less harmful to the environment. The possibility of supporting MnO(2) on clay materials may be explored and very cheap catalysts are likely to be obtained by depositing MnO(2) from colloidal solutions.