造孔剂对空气电极电性能的影响

为研究造孔剂的种类、含量对锌空电池空气电极电性能的影响,分别对添加不同用量的聚乙二醇200(PEG200)、(NH4)2C2O4和NH4HCO3等3种造孔剂的空气电极进行透气性能和稳态电流-电压极化曲线的测试,并用扫描电镜(SEM)对其防水透气膜和催化膜的表观形貌进行观察,研究结果表明:采用热分解造孔方法,在这3种造孔剂中PEG200的造孔效果最好;在防水透气膜和催化膜中分别添加质量分数为7.5%、15%的PEG200,所得空气电极在相同电位下的极化电流最大;由SEM观察可见:PEG200含量分别为7.5%、15%的防水透气膜和催化膜微孔的孔径分布更加均匀、孔隙率更大。     

阳极催化层孔结构对DMFC性能的影响

采用碳酸铵作为造孔剂,研究了阳极催化层孔结构对直接甲醇燃料电池(DMFC)性能的影响.热重、扫描电镜和压汞法分析的结果表明:碳酸铵的热分解使阳极催化层一次孔的孔容增大,而二次孔的孔容基本不变.电化学测试结果表明:与未加造孔剂的阳极催化层相比,加入碳酸铵使阳极催化层电化学活性表面积增加了26.6%;阳极电位为400 mV时的电流密度提高了53%;开路电位下的甲醇渗透率降低了12.5%;在80℃、0.2 MPa氧气条件下,DMFC的最高功率密度由186 mW/cm2提高到235 mW/cm2.     

太阳能电池中纳米TiO2多孔膜的制备

纳米TiO2多孔膜具有非常大的比表面积，其表面上吸附大量的染料分子进行敏化以后可以有效地吸收太阳光，并将其转化为电能。本介绍了染料敏化的纳米TiO2太阳能电池的基本结构和工作原理，以及染料敏化的纳米TiO2多孔膜的制备及研究现状。     

氧电极气体扩散层的研究

研究了不同含量PTFE对氧电极气体扩散层性能的影响;分别以丙三醇、Na2SO4、草酸铵、ZnO作为造孔剂,研究了不同造孔剂及含量对氧电极性能的影响;选用镍网做导电骨架,采取催化层/集流体/气体扩散层的排布方式,以纯铝为阳极,4 mol/L KOH溶液为电解液,将空气电极与铝阳极组装成电池,考察电池的性能,并通过扫描电镜(SEM)研究气体扩散层的表面形态。研究结果表明:当扩散层中PTFE的含量为60%,选用草酸铵为造孔剂,草酸铵与载体的质量比为3∶1时,电极内部的空气传导阻力小,整个氧电极的性能最佳。     

造孔剂对PEMFC膜电极性能的影响

在质子交换膜燃料电池(PEMFC)膜电极的催化层中加入造孔剂以减小气体反应物的扩散传质阻力。提出了两种新型造孔剂,分别为低分解温度的NH_4HCO_3和高溶解度的(NH_4)_2SO_4。实验结果表明,加入适量的造孔剂NH_4HCO_3,可使膜电极在H2-空气条件下的输出功率获得显著提高;加入适量的造孔剂(NH_4)_2SO_4,可使膜电极大电流工作时的性能得到明显改善。环境扫描电镜(ESEM)的测试结果表明,造孔剂的加入使膜电极催化层的孔结构得到优化,更有利于传质过程的顺利进行和提高催化剂Pt的利用率。     

固体氧化物燃料电池阳极基底造孔剂的研究

采用甘氨酸-硝酸盐法制备La0.7Sr0.3Cr0.5Mn0.5O3-d(LSCM)钙钛矿型阳极材料,采用传统干压成型法制备LSCM阳极基底。在阳极基底中分别加入不同种类和不同含量的造孔剂,采用扫描电子显微镜(SEM)观察阳极基底微观结构,并用质量体积法测量阳极的孔隙率。研究结果表明,当选用质量分数为8%的淀粉作为造孔剂时,阳极基底的微观性能最佳并得到最大的孔隙率。     

多孔碳电极用于多硫化钠-溴储能电池

研究了多硫化钠-溴(PSB)储能电池用多孔碳电极。电极材料为活性炭、导电炭黑、热塑性聚合物粘结剂,电极采用热压成型方法制备。用多孔炭电极作为电池正负极,系统地探讨了电极组成、活性炭颗粒粒径、造孔剂对电池充放电性能的影响。粘结剂量一定时,导电炭黑、活性炭比例存在最优值。大颗粒活性炭有利于保持电极的机械稳定性。加大造孔剂的量,促进了电极内孔的连通性,电池性能提高。活性炭制得的电极具有较高的电化学活性,在80 ℃、120 mA/cm2放电电流密度时比功率达0.14 W/cm2(1.19 V),可见活性炭是一种高性价比的PSB储能电池电极材料。     

碳酸氢铵对高载量干法电极性能的影响

为提高高载量干法电极极片孔隙率,用碳酸氢铵作极片造孔剂,热压去除造孔剂实现极片高孔隙率.研究表明,使用造孔剂后,极片中存在大量微孔,孔隙率显著增加,电极放电容量和循环性能均得到有效提高.数据表明,增加孔隙率能提高极片中锂离子迁移速率和减小极化,从而改善极片倍率性能.     

染料敏化太阳电池多孔TiO_2微结构的研究

太阳电池成为高性价比发电系统需要具备三个特点:高效率,高稳定性和低成本。但是高性价比的光伏发电系统至今仍未开发出来。低成本的太阳电池的制造不需要真空条件,如印刷,喷涂,旋涂,电化学沉积等。采用低成本的喷涂法在FTO导电玻璃基体上制备多孔纳米TiO2薄膜光阳极,电解液为0.50 mol/L LiI、0.05 mol/L I2的乙氰溶液,对电极为铂片,通过改变添加剂聚乙烯醇(PVA)的含量,研究PVA对染料敏化太阳电池多孔TiO2微结构及染料敏化太阳电池性能的影响。通过对光阳极扫描电子显微镜(SEM)、I-V曲线、TiO2薄膜染料吸附量和交流阻抗EIS图谱的分析,得到结果如下:随着聚乙烯醇(PVA)含量的增加,TiO2颗粒团聚程度减轻,暗电流逐渐减少但染料吸附量也在减小,当mPVA∶mTiO2=0.03∶0.12时,TiO2颗粒分布均匀,TiO2颗粒间能形成较好的电子通道,染料吸附量和暗电流达到最佳配匹,获得最好的光电转换效率为3.72%。     

SOFC用Ni/Al_2O_3金属陶瓷支撑层组织结构与气密性

采用氧乙炔火焰喷涂方法制备了含量不同的聚苯酯为造孔剂(PPHBA)的NiO/Al_2O_3涂层,系统地研究了造孔剂含量对涂层组织结构和气体渗透率的影响.研究结果表明,造孔剂的添加量对涂层的组织结构有显著影响,粉末中不添加造孔剂时,涂层的孔隙较少且分布均匀;涂层中添加造孔剂后,大气孔数量显著增多,且随着粉末中添加造孔剂含量的增加而增大.NiO/Al_2O_3涂层经高温还原处理后的渗透率显著高于喷涂态涂层渗透率,且气体渗透率随着喷涂粉末中造孔剂含量增加而增大.NiO还原处理后涂层的气体渗透率比喷涂态提高约一个数量级.     

基底及电解液对TiO_2纳米管阵列形貌的影响

通过中频脉冲磁控溅射的方法在ITO玻璃上沉积出致密的钛薄膜,分别以钛膜和钛箔为基底,在甘油和乙二醇为主的电解液体系中制备出TiO_2纳米管阵列,考察阳极氧化电压对纳米管形貌的影响,采用XRD、FESEM等测试手段对样品的组成、结构及形貌等进行表征。结果表明:氧化电压的增加会导致TiO_2纳米管管径和长度的增加,但氧化电压过高会造成钛箔基底TiO_2纳米管的坍塌,而ITO玻璃基钛膜上则会形成纳米深孔结构。     

Na/NiCl2电池正极材料表面形貌对其电化学性能影响

研究以镍粉为主要原料,通过粉末烧结法制成Na/NiCI2电池用正极材料.采用扫描电子显微镜、自动压汞仪、比表面积分析仪及恒流充放电等测试手段,对此正极材料的物理性质和电化学性能进行了测试和表征.研究表明造孔剂碳酸氢铵(NH4HCO3)的含量对正极材料的表面形貌及其电化学性能有显著的影响.添加质,分数为20%的造孔剂于还...     

直接乙二醇燃料电池阳极催化材料的研究进展

综述直接乙二醇燃料电池催化剂的催化反应机理,以及不同载体负载Pt、Pd单金属催化剂,掺杂金属Ru、Sn、Ni、Rh及金属氧化物WO3、Ti O2等合成二元和多元Pt系和非Pt系阳极电催化材料对乙二醇电催化氧化性能的研究现状,并对乙二醇电催化剂的研究方向进行展望。     

Growth of (Ba,Sr)TiO 3 Thin Films by MOCVD: Stoichiometry Effects

(Ba x Sr 1 m x )TiO 3 thin films were deposited in a planetary multi-wafer MOCVD reactor combined with a liquid delivery system using 0.35 molar solutions of Ba(thd) 2 and Sr(thd) 2 and a 0.4 molar solution of Ti(O-i-Pr) 2 (thd) 2 . The film growth on Pt-(111) was investigated within a wide parameter field, e.g., the deposition temperature was varied between 560C and 650C, which yields films with microstructures ranging from randomly oriented polycrystalline to perfectly (100)-textured columnar structures. Special emphasis is given to film stoichiometry: starting with (Ba 0.7 Sr 0.3 )TiO 3 the Group-II/Ti content was varied from 0.9 to 1.1 and the Ba content was reduced to the limit of pure SrTiO 3 films. The electrical properties of MIM structures were investigated after deposition of Pt top electrodes. The nominal thickness of the films was varied between 5 and 100 nm and permittivity and leakage current both are shown to depend strongly on the film thickness. These dependencies on the film thickness are analyzed within the phenomenological dead layer model. The dependence of the electrical properties on stoichiometry are discussed in detail.     

羰基铁/TiO2薄膜的制备及磁性能

在常压下用溶胶-凝胶法(不用酸作催化剂)制备了羰基铁/TiO2磁性薄膜,薄膜的颗粒尺寸为几十nm.通过原子力显微镜(AFM)、X射线衍射(XRD)、红外光谱(FT-IR)等方法分析材料形貌与微观结构,用振动样品磁强计和Agilent8722ES矢量网络分析仪对其磁性能进行了表征.结果表明,羰基铁粉颗粒表面均匀地包覆非晶态TiO2,钛酸正四丁酯与铁发生了键合作用.包覆后的复合薄膜的饱和磁化强度为163kA/m,矫顽力Hc仅为1.2kA/m.介电损耗型材料二氧化钛与磁损耗型材料羰基铁复合,可调节磁性能.     

CO2 Sensing Property of CuO-BaTiO3 Mixed Oxide Film Prepared by Self-Assembled Multibilayer Film as a Precursor

Preparation of CuO-BaTiO₃ mixed oxide thin film by the decomposition of a self-assembled multibilayer film as a molecular template was investigated in this study. Furthermore, CO₂ sensing property of the resultant thin film was investigated as a capacitive type sensor. The self-assembled bilayer film of few 1000 layers thickness can be obtained easily by casting an aqueous suspension consisting of dimethyldihexadecylammoiun bromide (DC1-16), Cu(ClO₄)₂, Ba(TiO(C₂H₄)₂), 2,6-dimetyle-3,5heptadione (DHP), and polyvinyl alcohol. Divalent copper ion (Cu²⁺)) which is associated with 2 DHP molecules was incorporated into the molecular bilayer film and BaTiO₃ precursor exists at the interspace of molecular bilayer film by coordinating with polyvinyl alcohol. Upquenching the organic-inorganic film at 1173 K leads to the uniform film of CuO-BaTiO₃ oxide mixture. Although operating temperature shifted to higher temperature, the resultant film exhibits the capacitance change upon exposure to CO₂. Consequently, it is concluded that the mixed oxide film of CuO-BaTiO₃ prepared by the decomposition of multibilayer film was also an appropriate capacitive type CO₂ sensor.     

CO2 Sensing Property of CuO-BaTiO3 Mixed Oxide Film Prepared by Self-Assembled Multibilayer Film as a Precursor

Preparation of CuO-BaTiO₃ mixed oxide thin film by the decomposition of a self-assembled multibilayer film as a molecular template was investigated in this study. Furthermore, CO₂ sensing property of the resultant thin film was investigated as a capacitive type sensor. The self-assembled bilayer film of few 1000 layers thickness can be obtained easily by casting an aqueous suspension consisting of dimethyldihexadecylammoiun bromide (DC1-16), Cu(ClO₄)₂, Ba(TiO(C₂H₄)₂), 2,6-dimetyle-3,5heptadione (DHP), and polyvinyl alcohol. Divalent copper ion (Cu²⁺)) which is associated with 2 DHP molecules was incorporated into the molecular bilayer film and BaTiO₃ precursor exists at the interspace of molecular bilayer film by coordinating with polyvinyl alcohol. Upquenching the organic-inorganic film at 1173 K leads to the uniform film of CuO-BaTiO₃ oxide mixture. Although operating temperature shifted to higher temperature, the resultant film exhibits the capacitance change upon exposure to CO₂. Consequently, it is concluded that the mixed oxide film of CuO-BaTiO₃ prepared by the decomposition of multibilayer film was also an appropriate capacitive type CO₂ sensor.     

不同造孔剂含量及电解质体系对DSSC的影响

采用料浆喷涂法制备了TiO2膜,当用电解质[0.1 mol/L碘化锂、0.05 mol/L碘、0.6 mol/L 1,2-二甲基-3-丙基咪唑碘(DMPII)、0.5 mol/L四叔丁基吡啶(TBP)的甲氧基丙腈溶液]时,固定TiO2、松油醇和聚乙烯醇缩丁醛(PVB)的比例,通过改变聚乙二醇(PEG-600)占TiO2质量的百分数,来研究它对电池性能的影响。研究发现PEG-600是通过改变TiO2膜的微观结构对电池性能产生影响的,当PEG-600质量分数为80%时,短路电流密度、染料吸附量、最大功率密度和光电转换效率达到较大;填充因子随PEG-600添加量的增加而增大,但是开路电压基本不变。当用电解质(0.25 mol/L碘化锂、0.025 mol/L碘、1.25 mol/L TBP的乙醇和碳酸丙烯酯溶液)时,测得电池的短路电流密度减小,但开路电压明显增高。     

TiO2包覆LiNi0.5Mn0.5O2的结构和电化学性能研究

通过溶胶-凝胶法在LiNi0.5Mn0.5O2表面包覆一层TiO2,采用X射线衍射(XRD),扫描电镜(SEM),恒电流充放电和电化学阻抗谱(EIS)对材料的结构、形貌及电化学性能进行了研究。实验结果表明,经过包覆后,有效地抑制了电解液对正极材料的侵蚀,包覆量为1.0%(质量分数)的放电容量略有提高,循环性能也得到明显改善。因此TiO2包覆是改善LiNi0.5Mn0.5O2材料的电化学性能的有效方法。