直接甲醇燃料电池阳极催化剂磷化镍的合成及其性能的研究

通过水热反应制备了Ni2P纳米粒子,该Ni2P纳米粒子在碱性溶液中对甲醇的氧化具有良好的催化性能。以Ni2P纳米粒子为阳极催化剂,并以Pt/C为阴极催化剂,搭建了在碱性条件下运行的直接甲醇燃料电池。研究结果显示,以空气为氧化剂,以甲醇为燃料,在常压、室温条件下工作,该碱性燃料电池的输出电流密度为40m A/cm2时,输出比功率为15m W/cm2,从而构建了一种阳极无铂基催化剂的直接甲醇燃料电池。     

常温下以甲烷为燃料的质子交换膜燃料电池发电可行性研究

尝试了常温下以甲烷为燃料的质子交换膜燃料电池发电的可能性，研究了温度和阳极催化剂对其燃料电池开路电压和放电性能的影响。结果表明，甲烷在常温下能够进行电化学氧化，随着电池工作温度的升高，燃料电池的开路电压和功率密度逐渐增加。阳极催化剂的铂含量和催化剂的组成对甲烷的电化学氧化具有非常大的影响。90℃下使用Pt（40wt．％）-Ru（20wt．％）／C为阳极催化剂（催化剂担载量：（2mg Pt＋1 mg Ru）·cm^-2），在以甲烷为燃料时，质子交换膜燃料电池功率密度达到了5．4mW·cm^-2。     

含硫化合物体系参比电极的选择和优化

Cl-、SO2-4等离子会影响含硫化合物电化学体系的复杂动力学。采用封闭体系参比电极(自制可逆氢电极)代替开放体系参比电极(饱和甘汞电极等),可以避免参比电极引入杂质离子。通过甘汞电极和自制可逆氢电极开路电位稳定性和电化学氧化影响对比分析,可以看出氢电极在硫氧化合物电化学体系具有良好的稳定性,12 h开路电位漂移小于±10 mV,稳定性优于饱和甘汞电极,体系复杂动力学现象明显,能更好的研究含硫化合物电化学复杂振荡体系的动力学。     

铝合金在碱性和中性溶液中电化学行为的研究

通过对铝阳极进行交流阻抗、塔菲尔曲线、析氢速率、开路电压测试,研究了多种铝合金在碱性和中性溶液中的电化学行为。发现Al-Ga-Sn-Mg和Al-Ga-Sn-Zn具有较好的电化学性能。与纯铝相比,在碱性电解液中,Al-Ga-Sn-Mg的开路电位负移70mV,抑制析氢速率为37.5%;在中性电解液中,Al-Ga-Sn-Mg合金的开路电位负移447mV。铝阳极在碱性和中性溶液中的反应机理不同。     

3D打印微生物燃料电池阳极及其性能特性

微生物燃料电池是一种处理废水同时产生电能的新型装置，阳极作为微生物燃料电池的重要组件极大地影响电池性能。针对微生物燃料电池传统三维电极结构不合理导致电极内部物质传输受限，电池功率密度较低的问题，本文采用3D打印技术并碳化的方式构建了结构可控的微生物燃料电池阳极，通过热重分析得到合适的碳化条件，并通过进一步的电化学分析和电极微观形貌拍摄研究了电极内部孔道结构对微生物生长情况和电池性能的影响。实验结果表明：电极孔径尺寸为0.4mm时，电池具有最优性能，其最大功率密度达12.85W/m²，比采用碳布阳极的MFC提升10倍，较采用碳毡阳极的燃料电池高38%；具有可控孔道结构电极的传荷阻抗和传质阻抗是限制电极性能的主要因素，通过优化孔道尺寸和结构分布可降低其传荷及传质阻抗，可以进一步提升电池性能。     

GO/PEDOT复合材料修饰阳极的制备及其在MFC中的应用

微生物燃料电池(MFC)是一种利用微生物将有机物中的化学能直接转化成电能的装置,通过改善阳极特性可以有效提高微生物燃料电池的产电性能。通过恒电流法电沉积制备了氧化石墨烯/聚3,4-乙烯二氧噻吩(GO/PEDOT)复合材料修饰碳毡(CF)阳极。通过循环伏安法和交流阻抗法考察了电极特性。将其应用到微生物燃料电池中,对其产电性能进行评价。结果表明,GO/PEDOT-CF电极具有较大的比表面积和优良的电化学性能;以GO/PEDOT-CF为阳极的微生物燃料电池,产电性能良好,其最大功率密度和最大电流密度达到1.138W·m?2和4.714 A·m?2,分别是未修饰阳极的4.80倍和5.51倍。因此,GO/PEDOT复合材料是一种优良的阳极修饰材料,可有效提高MFC的产电性能。     

锌-空气电池Co-PPy-C复合催化剂的电化学性能研究

采用化学氧化聚合法合成了以碳为载体的钴-聚吡咯(PPy)配合物Co-PPy-C,作为气体扩散电极的氧还原催化剂。利用极化曲线、交流阻抗、计时电流等电化学方法测试了其在碱性介质中(6 mol/L KOH)氧气气氛条件下氧还原的催化性能。电极电位在-0.20 V vs.Hg/HgO时,催化剂电流密度达到158 mA/cm2,显示出优越的氧还原电催化性能;采取催化层/集流体/气体扩散层的排布方式,以纯锌为负极,6 mol/L的KOH为电解液,将气体扩散电极与锌负极组装成锌-空气电池。电池以80 mA/cm2进行恒流放电,放电电压为1.0 V,且性能稳定。     

稀薄燃料气氛下中空全对称双阴极SOFC的电化学特性EI北大核心CSCD

制作了LSCF/GDC/8YSZ/NiO-8YSZ/NiO-3YSZ/NiO-8YSZ/8YSZ/GDC/LSCF中空全对称双阴极阳极支撑平板式固体氧化物燃料电池（SOFC）,研究了其在稀薄燃料气氛下的电化学特性。结果表明：该结构电池在稀薄燃料气氛下稳定循环放电11次后依然保持稳定,在纯N2气氛下电池的最大输出功率密度可达8.79 mW/cm^2。该结构电池中Ni与NiO所形成的氧化还原不仅对电池性能无影响,并且还能够作为储能媒介,为后续发展以电池阳极金属作为储能介质的高温固态电池提供了可能。     

温度对电沉积氢氧化镍电化学性能的影响

在0.1mol/L的Ni(NO3)2溶液中,采用电化学沉积法制备出适用于锌镍微电池的氢氧化镍电极,研究了电沉积温度对Ni(OH)2电极的电化学循环伏安性能以及充放电性能的影响。测试结果表明,电沉积方法制备的Ni(OH)2电极适合于微电池的制作。30°C下电沉积制备的Ni(OH)2电极具有优异的电化学性能,其质子扩散系数为7.71×10-12cm2/s,放电比容量为1285μAh/cm2,利用率达91.4%。     

稀薄燃料气氛下中空全对称双阴极SOFC的电化学特性

制作了LSCF/GDC/8YSZ/NiO-8YSZ/NiO-3YSZ/NiO-8YSZ/8YSZ/GDC/LSCF中空全对称双阴极阳极支撑平板式固体氧化物燃料电池(SOFC),研究了其在稀薄燃料气氛下的电化学特性。结果表明:该结构电池在稀薄燃料气氛下稳定循环放电11次后依然保持稳定,在纯N_2气氛下电池的最大输出功率密度可达8.79 mW/cm~2。该结构电池中Ni与NiO所形成的氧化还原不仅对电池性能无影响,并且还能够作为储能媒介,为后续发展以电池阳极金属作为储能介质的高温固态电池提供了可能。     

The polarization behavior of the anode in a microbial fuel cell

Microbial fuel cell (MFC) systems are unique electrochemical devices that employ the catalytic action of bacteria to drive the oxidation of organic compounds. These systems have been suggested as renewable energy sources for small remote devices; however, questions remain about how MFCs can be efficiently optimized for this purpose. Several electrochemical techniques have been employed in this study to elucidate the limiting factors in power production by MFCs. Impedance spectra were collected for the anode and cathode at their open-circuit potential (OCP) before and after all other electrochemical tests. Cell voltage-current curves were obtained using a potential sweep technique and used to determine the maximum power available from the system. Potentiodynamic polarization in two different potential regions was used to determine the exchange current for the reaction occurring at the anode at its OCP and to explore the polarization behavior of the anode and the cathode in a wide potential range. Cyclic voltammetry was used to evaluate the redox activity of the anode. These techniques used in combination showed that the microorganism Shewanella oneidensis MR-1 is solely responsible for the observed decrease of the OCP of the anode, the increased rate of oxidation of lactate, the larger cell voltage and the increased maximum power output of the MFC.     

Formic acid oxidation by carbon-supported palladium catalysts in direct formic acid fuel cell

The oxidation of formic acid by the palladium catalysts supported on carbon with high surface area was investigated. Pd/C catalysts were prepared by using the impregnation method. 30 wt% and 50 wt% Pd/C catalysts had a high BET surface area of 123.7 m²/g and 89.9 m²/g, respectively. The fuel cell performance was investigated by changing various parameters such as anode catalyst types, oxidation gases and operating temperature. Pd/C anode catalysts had a significant effect on the direct formic acid fuel cell (DFAFC) performance. DFAFC with Pd/C anode catalyst showed high open circuit potential (OCP) of about 0.84 V and high power density at room temperature. The fuel cell with 50 wt% Pd/C anode catalyst using air as an oxidant showed the maximum power density of 99 mW/cm². On the other hand, a fuel cell with 50 wt% Pd/C anode catalyst using oxygen as an oxidant showed a maximum power density of 163 mW/cm² and the maximum current density of 590 mA/cm² at 60 °C.     

Membraneless laminar flow-based micro fuel cells operating in alkaline, acidic, and acidic/alkaline media

The lack of a polymer electrolyte membrane (PEM, e.g. Nafion) in membraneless, laminar flow-based micro fuel cells (LF-FCs) eliminates several PEM-related issues such as fuel crossover, cathode flooding, and anode dry-out, as we reported previously. This paper explores the media flexibility of LF-FCs by working in acidic and alkaline media, as well under “mixed-media” conditions in which the anode is in acidic media while the cathode is in alkali, or vice versa. Operating a fuel cell under alkaline conditions has positive effects on the reaction kinetics, both at the anode and cathode, while the cell performance under “mixed-media” conditions offers an opportunity to increase the maximum achievable open cell potential (OCP). The lack of media-related constraints and the simplicity of the LF-FC design allow for these experiments to be performed consecutively in a single LF-FC without changing the system, except for altering the composition/pH of the fuel and oxidant stream. The performance of LF-FCs operated with different media is described and compared.     

PMMA含量对水系流延IT-SOFC性能的影响

通过向阳极添加单一分散性的球形造孔剂PMMA改善阳极的微观结构,研究不同含量的PMMA对阳极的孔隙率、显微结构、电性能的影响。文中分别制备了造孔剂(PMMA)含量分别为6wt.%、8wt.%、10wt.%和12wt.%四种阳极材料的单电池,通过测试阳极还原前的开口气孔率分别为17vol.%,22.4vol.%,30.6vol.%和42.1vol.%;单电池的最大功率密度分别为0.66W/cm2、0.78W/cm2、1.15W/cm2和1.01W/cm2;极化电阻分别为1.12Ω.cm2、1.03Ω.cm2、0.88Ω.cm2和1.02Ω.cm2。实验结果表明:以单一分散性的球形PMMA为SOFC阳极材料的造孔剂,其最佳添加量为10wt.%,所制备的单电池可以获得最佳的电化学性能,即以3%H2O+H2为燃料气,750℃下,单电池的开路电压(OCV)为1.01V,最大功率密度为1.15W/cm2,极化电阻为0.88Ω.cm2。     

硫化氢恶臭气体吸收液的电化学氧化处理过程

利用单槽无隔膜电化学反应器,研究了硫化氢恶臭气体碱性吸收液在圆形平板钌钛DSA电极上的电化学氧化处理过程,考察了电流密度、初始料液浓度、辅助电解质以及pH值对S2?电解去除效果的影响。结果表明：在电流密度25 mA/cm2、S2?初始浓度23 mmol/L时,S2?去除率可达95%以上;S2?的氧化产物主要为SO42?,约占总反应产物的95%,而硫单质占2%～3%,同时生成少量SO32?、S2O32?;S2?去除速率受到S2?浓度的较大影响,电流密度越高去除速率越快;pH值影响Sx2?的形成,强碱条件可避免阳极钝化;与NaCl等辅助电解质相比,NaOH最有利于提高电解氧化的速度和深度,S2?去除率达90%时,可缩短处理时间近40%。     

造孔剂含量对固体氧化物燃料电池阳极的结构与电性能的影响

通过向阳极添加造孔剂（PMMA）改善阳极的微观结构,研究不同含量的造孔剂（PMMA）对阳极的显微结构、电性能的影响。利用SEM、电化学1二作站等测试手段对单电池的结构和电性能进行了表征。研究结果表明,添加7wt．％的PMMA造孔剂制备的单电池,阳极的孔隙率高,阳极中的气孔分布均匀,结构规整,降低了燃料气的传输阻力,提高了三相反应界面,获得了良好的电性能。以H2＋3％H：0为燃料气,在750℃下单电池的开路电压（OCV）为1．08V、最大功率密度为0．82W／cm2、欧姆阻抗为0．20Ω·cm2、两极阻抗为0．53Ω·cm2。     

以Ni-YSZ和Sm0.5Sr0.5Fe0.8Cu0.2O3-δ为电极的微管固体氧化物燃料电池的制备及电化学性能（英文）

分别以Ni-YSZ中空纤维为阳极和Sm0.5Sr0.5Fe0.8Cu0.2O3–δ–Sm0.2Ce0.8O1.9（SSFCu-SDC）为阴极制备了微管固体氧化物燃料电池（SOFC）。利用扫描电子显微镜（SEM）、电化学工作站表征了微管单电池的显微结构与电化学性能。SEM分析表明,采用相转化法制备的Ni-YSZ中空纤维阳极呈特殊的非对称结构,主要由中间海绵状结构和内外两侧的指孔状多孔结构构成。通过真空辅助浸渍涂覆法和与阳极共烧技术在阳极支撑体上制备了致密的YSZ电解质膜和SDC过渡层。分别采用湿氢为燃料和静态环境空气为氧化剂测定了制备的微管单电池在650～750℃时的电化学性能。结果表明,该微管单电池具有高的输出性能,在750、700℃和650℃时的最大功率密度分别可达到485.9、382.7mW/cm2和260.3mW/cm2。     

Preparation of a PVA/HAP composite polymer membrane for a direct ethanol fuel cell (DEFC)

A novel PVA/Hydroxyapatite (HAP) composite polymer membrane was prepared by the direct blend process and solution casting method. The characteristic properties of the PVA/HAP composite polymer membranes were investigated using thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), micro-Raman spectroscopy and the AC impedance method. An alkaline direct ethanol fuel cell, consisting of an air cathode with MnO₂ carbon inks based on Ni-foam, an anode with PtRu black on Ni-foam, and the PVA/HAP composite polymer membrane, was assembled and investigated. It was found that the alkaline direct ethanol fuel cell comprising of a novel cheap PVA/HAP composite polymer membrane showed an improved electrochemical performance in ambient temperature and air. As a result, the maximum power density of the alkaline DEFC, using a PtRu anode based on Ni-foam (10.74 mW cm⁻²), is higher than that of DEFC using an E-TEK PtRu anode based on carbon (7.56 mW cm⁻²) in an 8M KOH + 2M C₂H₅OH solution at ambient temperature and air. These PVA/HAP composite polymer membranes are a potential candidate for alkaline DEFC applications.     

Preparation of Pt-Pd catalysts for direct formic acid fuel cell and their characteristics

Pt-Pd catalysts were prepared by using the spontaneous deposition method and their characteristics were analyzed in a direct formic acid fuel cell (DFAFC). Effects of calcination temperature and atmosphere on the cell performance were investigated. The calcination temperatures were 300, 400 and 500 °C and the calcination atmospheres were air and nitrogen. The fuel cell with the catalyst calcined at 400 °C showed the best cell performance of 58.8 mW/cm². The effect of calcination atmosphere on the overall performance of fuel cell was negligible. The fuel cell with catalyst calcined at air atmosphere showed high open circuit potential (OCP) of 0.812 V. Also the effects of anode and cathode catalyst loadings on the DFAFC performance using Pt-Pd (1: 1) catalyst were investigated to optimize the catalyst loading. The catalyst loading had a significant effect on the fuel cell performance. Especially, the fuel cell with anode catalyst loading of 4 mg/cm² and cathode catalyst loading of 5 mg/cm² showed the best power density of 64.7 mW/cm² at current density of 200 mA/cm². This work was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.     

中温H2S-空气燃料电池阴极催化剂的研究

Abstract Cathode catalysts comprising composite NiO, NiO-Pt, or LiNiO2 have been developed for electro- chemical oxidation of hydrogen sulfide in intermediate-temperature solid oxide fuel cells （ITSOFCs）. All catalysts exhibited good electrical conductivity and catalytic activity at operating temperature. Composite NiO catalysts were found to be more active and have lower over potential and higller current density than pure Pt although the electrical conductivity of NiO itself is lower than that of Pt. This problem has been overcome by either admixing as high as 10% （by mass）Ag powder into NiO_ cathode layer or using composite NiO c atalysts such as NiO-Pt and LiNiO2 catalysts. Composite catalysts like NiO with Ag, electrolyte and starch admixed, NiO-Pt, which was prepared from a mixture of NiO and Pt powders, by admixing electrolyte and starch, and LiNiO2, which is derived from the reaction of LiOH-H2O and NiO with electrolyte and starch admix_ed have been shown to be feasible and effective in an intermediate-temperature H2S-air fuel cell. A fuel cell using Li2SO4-based proton-conducting membrane as electrolyte, metal sulfides as anode catalysts, and composite NiO as cathode catalysts produced a maximum current density about 300mA·cm^-2 and maximum power density over 80 mW-cm-2 at 680℃.