聚苯胺包覆CoFe类普鲁士蓝复合材料的超电容性能

制备了聚苯胺包覆CoFe类普鲁士蓝纳米立方（CoFePBA@PANI）复合材料,采用XRD、FTIR、SEM和TEM对CoFePBA@PANI复合材料的结构和形貌进行表征,利用循环伏安法（CV）、恒电流充放电法及交流阻抗法（EIS）对CoFePBA@PANI复合材料的电化学性能进行了考察。结果表明:通过植酸的配位作用促使苯胺在具有面心立方结构的CoFePBA表面发生聚合反应,形成了具有核-壳结构的CoFePBA@PANI复合材料。系统地研究了PANI的含量对CoFePBA@PANI复合材料电化学性能的影响,CoFePBA@PANI复合材料在0.5 mol/L Na₂SO₄和H₂SO₄的混合酸性介质中,在1 A/g电流密度下,比电容值达到401.2 F/g,电流密度增大至10 A/g时,比电容仍能保持在367.3 F/g。      

Co类普鲁士蓝/多壁碳纳米管纳米复合材料的制备及其超电容性能

Co类普鲁士蓝（CoPBA）作为令人瞩目的超级电容器阳极材料拥有高比容量和优异的循环稳定性,但较差的电子导电性限制了其倍率性能。利用ZIF-67作为前驱体合成了Co类普鲁士蓝/多壁碳纳米管（CoPBA/MWCNT）复合材料,并使用XRD、SEM和TEM对材料的结构和形貌进行表征。在三电极体系中,测得CoPBA/MWCNT电极在电流密度为1 A·g^-1时电容提高到312 F·g^-1。制备的CoPBA/MWCNT电极有利于提高材料电导率和机械稳定性,从而获得更高的电化学性能。将CoPBA/MWCNT正极和活性炭（AC）负极组装为非对称电池,测得5 000圈循环后容量保留率为83.1%,循环稳定性优异。     

近球状钼酸镍/多壁碳纳米管复合材料的制备及其赝电容性能

以硝酸镍、钼酸钠和多壁碳纳米管为原料, 通过水热反应法制备了钼酸镍/多壁碳纳米管(NiMoO₄/MWCNTs)复合材料。采用扫描电子显微镜、X射线能谱和X射线衍射对材料组成和形貌进行表征。结果表明: MWCNTs 很好地包覆在球状NiMoO₄外表面, 且各元素均匀地分布在材料中。循环伏安和电化学阻抗实验证实MWCNTs显著增强了NiMoO₄的氧化还原信号和电荷转移动力学特性。电容测试实验进一步表明, 复合材料较NiMoO₄单一材料具有更高的比电容、倍率特性及循环稳定性, 且当MWCNT含量为40 mg时, 所得产物(NiMoO₄/MWCNTs-40)具有最佳的电化学性能。电流密度为2 A/g时, NiMoO₄/MWCNTs-40复合材料的比电容高达1071 F/g; 当电流密度增大到10 A/g时, 比电容仍能保持原来的66.10%。在10 A/g的电流密度下, 经过2500次循环充放电后, NiMoO₄/ MWCNTs-40复合材料的比电容保持率高达95.85%, 表明该材料具有出色的循环稳定性。     

普鲁士蓝及普鲁士蓝类化合物材料在钠离子电池中的研究进展

近年来,普鲁士蓝(PB)及普鲁士蓝类化合物(PBAs)用于钠离子电池电极材料方面的研究逐渐深入.作为金属有机框架(MOFs)材料,PB及PBAs是具有可调控的化学组成和物理性质的简单配位聚合物.PB及PBAs可直接作为高性能钠离子电池正极材料,也可以通过与其他材料复合用于钠离子电池正极;此外,利用PB及PBAs作为前驱体制备各类具有纳米结构的金属化合物(如金属氧化物、金属硫化物、金属硒化物和金属磷化物等)及金属化合物复合材料,并用于钠离子电池负极.本文简要介绍了PB、PBAs和以它们为前驱体制备的金属化合物及复合材料在钠离子存储方面的应用研究进展.     

多壁碳纳米管的裁剪及其电容性能研究

商业化的多壁碳纳米管通常是相互缠绕且紧密团聚,长度高达数十微米,不利于电解液离子的传输,尤其是难以利用碳纳米管内部空间.本文通过简单的化学氧化方法从横向和纵向同时裁剪多壁碳纳米管,形成弯曲的石墨烯带(CGS),将其浸入0.1 mol?L?1高锰酸钾溶液中,合成了CGS-MnO2复合材料.利用FESEM、TEM、XRD、...     

聚苯胺/石墨烯/金复合材料的制备及超电容性能研究

以对苯二胺( p-PDA)为单体,氯金酸(HAuCl4)为氧化剂和Au源,氧化石墨烯(GO)为基底,通过原位聚合伴随Au纳米粒子生成的方法获得了聚苯胺/石墨烯/金(PpPD/GO/Au)的纳米复合材料.FESEM、FT-IR、XRD等测试表明,聚苯胺类衍生物、氧化石墨烯以及金纳米粒子三相在整个纳米复合材料中共存.材料的...     

5-磺基水杨酸掺杂聚吡咯/ZIF67复合材料的超电容性能

为充分利用金属-有机框架化合物(MOF)丰富的多孔结构与导电聚合物的独特掺杂结构,研究掺杂剂对MOF/导电聚合物复合材料的结构及电化学性能的影响,以实现稳定的化学掺杂。通过调控Co²⁺与2-甲基咪唑的摩尔配比常温反应制备得到三维花状结构的ZIF-67(命名为Z8);利用简便的原位聚合反应制备得到5-磺基水杨酸(5-SSA)掺杂聚吡咯(PPy)/Z8复合材料。Z8的引入能在一定程度上减少PPy微球的堆积,其与5-SSA之间的多重氢键、共轭效应等有利于PPy实现稳定的化学掺杂,其有利于电子及电解质离子的快速传输,并为PPy提供支撑。电化学测试结果表明,所有的复合材料中,PPy/10wt%Z8可获得最佳的电化学性能,其在1 A·g^-1的电流密度下的比电容可达300 F·g^-1。以PPy/10wt%Z8为正极,活性炭为负极,柔性碳布作为支撑体,聚乙烯醇(PVA)-H₂SO₄为电解质组装得到柔性非对称超级电容器,在1 mA·cm^-2的电流密度下,其比电容为200 m...     

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。     

发射状OMS2型MnO2的制备及其超级电容性能

在不同的反应时间下水热法控制制备发射状超级电容器用MnO2电极材料,采用X射线衍射光谱(XRD)、扫描电镜(SEM)表征其结构,采用循环伏安、恒流充放电和交流阻抗研究其电化学电容性能。结果表明,制备的MnO2为隐钾锰矿型,具有发射状结构,随着反应时间的延长,MnO2的晶型从不完善逐渐变得完善,发射状结构逐渐明显、增大,并且MnO2辐射出的每根单枝从较细的纳米刺逐渐生长为四方结构的纳米棒;在5mA/cm2的电流密度下,最高比电容达到了448F/g;随着反应时间的增加,MnO2电极的比容量先增长再降低。     

铁基普鲁士蓝正极材料的制备及储钠性能的研究

用简单的共沉淀法合成铁基普鲁士蓝正极材料,并研究合成温度对材料微观形貌和储钠性能的影响。研究结果显示,随着合成温度的提高,产物颗粒尺寸变大,钠含量增加。FeHCF-40℃电极材料,在30 mA/g电流密度下,首次放电比容量为132.3 mAh/g,循环100次后,放电比容量仍有102.4 mAh/g,容量保持率为77.4%;且当电流密度增大到1 500 mA/g时,仍可实现80.3 mAh/g的比容量,显示出优异的倍率性能和循环性能。     

Synergistic electro-co-deposition and molecular mixing for reinforcement of multi-walled carbon nanotube in copper

Carbon nanotube-reinforced copper composite powder was prepared by a modified electro-co-deposition method that was carried out on small diameter (3 mm) tip of the cathode. The deposition was done at room temperature and atmospheric pressure. Samples were prepared under constant stirring by a magnetic stirrer. Transmission and scanning electron microscopy confirms the dispersion of multiwalled carbon nanotubes (MWCNT) in the copper matrix. Dispersion of MWCNTs in copper matrix by this method is very easy and the set up can be easily scaled up for the bulk production of MWCNT reinforced copper powder. The method for the fabrication of MWCNT reinforced copper powder; microstructure and morphology of the powder formed are reported.     

Electrochemical deposition of Prussian blue on hydrogen terminated silicon(111)

Electrochemical deposition of Prussian blue (PB) was performed by cyclic voltammetry on hydrogen terminated n-type Si(111) surface. The characterization of the samples based on atomic force microscopy and X-ray diffraction spectroscopy showed a nanocrystal form of the PB films on the silicon surface. The thickness of PB films as a function of the potential cycling number was monitored simultaneously by Raman spectroscopy, proving that the growth of the films is in a good controllable manner.     

High-efficiency microwave absorption performance of cobalt ferrite microspheres/multi-walled carbon nanotube composites

Journal of Materials Science: Materials in Electronics - In this article, spinel ferrite CoFe2O4 and multi-walled carbon nanotubes (MWCNTs) composites are constructed by a facile one-step...     

Mechanical properties of multi-walled carbon nanotube/epoxy composites

Untreated and acid-treated multi-walled carbon nanotubes (MWNT) were used to fabricate MWNT/epoxy composite samples by sonication technique. The effect of MWNT addition and their surface modification on the mechanical properties were investigated. Modified Halpin–Tasi equation was used to evaluate the Young’s modulus and tensile strength of the MWNT/epoxy composite samples by the incorporation of an orientation as well as an exponential shape factor in the equation. There was a good correlation between the experimentally obtained Young’s modulus and tensile strength values and the modified Halpin–Tsai theory. The fracture surfaces of MWNT/epoxy composite samples were analyzed by scanning electron microscope.     

Stress-strain behavior of multi-walled carbon nanotube/PEEK composites

This study examined the effects of multi-walled carbon nanotube (CNT) dispersion on stress-strain behaviors of poly-ether-ether-ketone (PEEK) at room temperature. Tensile test specimens containing 9 wt.% and 15 wt.% of CNT were fabricated using injection molding. Results of focused ion beam (FIB) observations show that many CNTs in the CNT/PEEK composite are aligned longitudinally. Although the PEEK stress-strain behavior is almost linear up to 1.5% strain, the stress-strain curves of CNT/PEEK composites exhibit considerable nonlinear and hysteretic behaviors from extremely low strain (<0.1%) under both tensile and compressive loading. The experimental results suggest that the viscoelastic deformation effects on nonlinear and hysteresis behaviors are not strong below 1.5% strain. Presumably, the slippage at the CNT-PEEK interface occurs with increasing applied stress because of poor interfacial load-transfer capability.     

AC-impedance response of multi-walled carbon nanotube/cement composites

AC-impedance spectroscopy (AC-IS) was combined with time-domain reflectometry (TDR) to investigate the impedance response of fiber-reinforced cement (FRC) composites with multi-walled carbon nanotubes (MWCNTs). In Nyquist plots (−imaginary impedance vs. +real impedance) three impedance arcs/features were observed, similar to Nyquist plots for macrofiber and microfiber FRCs. The intersection of the electrode arc and the intermediate frequency feature (R_DC(FRC)) corresponds to the DC resistance of the composite. The intersection of the two bulk features (R_cusp) corresponds to the AC resistance of the composite. Reductions in (R_DC(FRC)) from the matrix resistance are indicative of a nanotube percolating network. Reductions in R_cusp from the matrix resistance are indicative of a discontinuous fiber–fiber path. Both shifts increased with fiber loading. AC-IS measurements are therefore able to discriminate percolation vs. discontinuous fiber effects in CNT-FRCs, with the potential for characterizing dispersion issues (e.g., clumping/aggregation) in nanocomposites.     

Effects of stretching on mechanical properties of aligned multi-walled carbon nanotube/epoxy composites

Composites based on epoxy resin and differently aligned multi-walled carbon nanotube (MWCNT) sheets have been developed using hot-melt prepreg processing. Aligned MWCNT sheets were produced from MWCNT arrays using the drawing and winding technique. Wavy MWCNTs in the sheets have limited reinforcement efficiency in the composites. Therefore, mechanical stretching of the MWCNT sheets and their prepregs was conducted for this study. Mechanical stretching of the MWCNT sheets and hot stretching of the MWCNT/epoxy prepregs markedly improved the mechanical properties of the composites. The improved mechanical properties of stretched composites derived from the increased MWCNT volume fraction and the reduced MWCNT waviness caused by stretching. With a 3% stretch ratio, the MWCNT/epoxy composites achieved their best mechanical properties in this study. Although hot stretching of the prepregs increased the tensile strength and modulus of the composites considerably, its efficiency was lower than that of stretching the MWCNT sheets.