新型直接碳燃料电池阴极材料及其性能

考察了Ni-CeO2复合阴极对直接碳燃料电池(DCFC)输出性能的影响. 使用不同组成的Ni-CeO2复合阴极对DCFC性能进行了测试. 结果表明,使用Ni-CeO2复合阴极可显著提高DCFC在500和630℃工作时的电流密度、功率密度和燃料转化效率,500℃下DCFC最大电流密度、功率密度分别为328 mA/cm2和72 mW/cm2. 630℃下DCFC最大电流密度、功率密度分别为474 mA/cm2和108 mW/cm2,电流密度50 mA/cm2时燃料转化效率为70%. 用XRD和SEM对Ni-CeO2复合阴极材料进行了表征,并对Ni-CeO2复合阴极可能的作用机制进行了研究.     

液体催化燃料电池的放大试验研究

液体催化燃料电池技术是一种基于电化学原理将生物质能直接转化为电能的绿色、高效生物质燃料电池发电技术。为了研究大功率的液体催化燃料电池技术发电性能,对液体催化燃料电池进行了功率放大试验研究。开发出放电面积为100cm2的单电池,通过将组建的小型燃料电池组和中型燃料电池组串联,搭建出一个发电功率为52 W的燃料电池电堆,并对该燃料电池电堆的泵损耗和造价成本进行初步分析。结果表明,该燃料电池电堆的泵损耗为9. 87 W,占电堆发电功率的19%,整个燃料电池系统的总造价成本为1. 55万元。     

用于污水处理的微生物燃料电池研究最新进展

微生物燃料电池技术目前取得了突破性的进展,并迅速成为废水处理的热点.本文介绍了微生物燃料电池的工作原理和特点,结合微生物燃料电池的发展,对其结构、运行条件,产电微生物及提高电池产电性能作了综述,探讨了提高微生物燃料电池性能的关键问题,并展望其应用前景.     

废水处理新理念——微生物燃料电池技术研究进展

近年来微生物燃料电池技术在国外接连取得突破性研究成果,并迅速成为新概念废水处理的热点。介绍了微生物燃料电池技术的原理和特点,系统综述了该项技术的研究进展,重点总结了在产电菌、系统构型与材料研究等方面的最新研究成果,分析了存在的问题,在此基础上指出微生物燃料电池技术研究的重点突破方向。     

微生物燃料电池堆栈技术研究

微生物燃料电池是一种处理废水的同时产电的具有广阔应用前景的新型水处理技术,其堆栈技术是产生更高电压和电流的核心技术。本文介绍了微生物燃料电池的工作原理及其局限性,集中阐述了微生物燃料电池堆栈技术的挑战及可能解决问题的研究方向,为进一步研究和开发高性能的微生物燃料电池提供依据。     

燃料电池的发展趋势

介绍了燃料电池的工作原理、优缺点;同时以燃料电池应用为背景,综述不同类型的燃料电池如车用质子交换膜燃料电池、航天飞行器用再生燃料电池、小型便携式产品用直接甲醇燃料电池、中小型电站用固体氧化物燃料电池(SOFC)、微生物燃料电池(MFC)的技术发展现状与研究热点,并指出了未来燃料电池的发展趋势.     

微生物燃料电池高效产电的研究进展

结合微生物燃料电池研究进展,从提高微生物燃料电池的产电性能出发,讨论了目前微生物燃料电池发展的主要限制因素和应用前景。对影响微生物燃料电池产电性能的4个主要影响因素,电池构型、阳极室(电活性微生物、阳极材料)、阴极室(电子受体、催化剂)、阴阳极分隔材料进行了分析。认为目前对于低成本的电极材料和构型的扩大研究较少,微生物燃料电池由于其成本较高、产能较低,仍然难以进行实际的扩大应用。开发出低成本的电极材料和催化剂,并在实际应用中将其与其他水处理技术进行耦合应是是未来微生物燃料电池的研究重点。在此基础上,建立和优化微生物燃料电池数学模型,深入研究堆叠式微生物燃料电池产生的电压反转的原因也会对未来这一技术的改进提供可靠的帮助。     

微生物燃料电池技术底物的研究进展

微生物燃料电池技术可将污水中蕴藏的化学能直接转化为电能输出,是实现污水资源化的重要途径之一,受到广泛关注。文章重点综述了微生物燃料电池技术在底物拓展方面的研究历史与现状,并针对当前研究的不足,提出了微生物燃料电池未来发展的方向。     

厌氧流化床微生物燃料电池研究进展

厌氧流化床微生物燃料电池采用液固流化床耦合微生物燃料电池技术,使流体与微生物载体颗粒充分混合,可显著提高相间传质效率,进而提升废水处理及电池产电效率。综述了厌氧流化床微生物燃料电池的工作原理及优缺点,分析了温度、pH值、外阻、电极、驯化方式、内阻、基质流速等因素对电池产电性能的影响,介绍了电池的应用前景,并对其未来主要的研究方向进行了展望。     

大连化物所研制成功燃料电池

我国首台燃料电池汽车在湖北省十堰市试车成功。这台车上使用的燃料电池是辽宁省大连化物所研制的、具有独家知识产权的产品。电池电动汽车是目前世界各国关注的“绿色汽车” ,其主要难题是电池技术。大连化物所此次研制的质子交换膜燃料电池可以室温启动 ,能量转化率高达 6 0 % ;以纯氢作燃料时 ,排出的是水 ,无噪音和尾气污染 ,从而实现了污染的零排放 ,被认为是未来电池汽车的最佳动力源。大连化物所研制成功燃料电池     

DIRECT ELECTROCHEMICAL POWER GENERATION FROM CARBON IN FUEL CELLS WITH MOLTEN HYDROXIDE ELECTROLYTE

Historically, despite its compelling cost and performance advantages, the use of a molten metal hydroxide electrolyte has been ignored by direct carbon fuel cell (DCFC) researchers, primarily due to the potential for formation of carbonate salt in the cell. This article describes the electrochemistry of a patented medium-temperature DCFC based on a molten hydroxide electrolyte, which overcomes the historical carbonate formation.

An important technique discovered for significantly reducing carbonate formation in the DCFC is to ensure a high water content of the electrolyte. To date, four successive generations of DCFC prototypes have been built and tested to demonstrate the technology - all using graphite rods as their fuel source. These cells all used a simple design in which the cell containers served as the air cathodes and successfully demonstrated the ability to deliver more than 40 A with the current density exceeding 250 mA/cm². Conversion efficiency greater than 60% was achieved.     

DIRECT ELECTROCHEMICAL POWER GENERATION FROM CARBON IN FUEL CELLS WITH MOLTEN HYDROXIDE ELECTROLYTE

Historically, despite its compelling cost and performance advantages, the use of a molten metal hydroxide electrolyte has been ignored by direct carbon fuel cell (DCFC) researchers, primarily due to the potential for formation of carbonate salt in the cell. This article describes the electrochemistry of a patented medium-temperature DCFC based on a molten hydroxide electrolyte, which overcomes the historical carbonate formation.

An important technique discovered for significantly reducing carbonate formation in the DCFC is to ensure a high water content of the electrolyte. To date, four successive generations of DCFC prototypes have been built and tested to demonstrate the technology – all using graphite rods as their fuel source. These cells all used a simple design in which the cell containers served as the air cathodes and successfully demonstrated the ability to deliver more than 40 A with the current density exceeding 250 mA/cm². Conversion efficiency greater than 60% was achieved.     

Study on the preparation of activated carbon for direct carbon fuel cell with oak sawdust

Direct carbon fuel cell (DCFC) is a device, which converts chemical energy of carbon into electrical energy through electrochemical oxidisation directly and its performance enormously depends on the characteristics of the fuel used. In this study, oak sawdust is used to prepare the activated carbon for the DCFC, with K₂CO₃ as the activating agent. Nickel catalyst is applied to improve the electrical conductivity, while HNO₃ treatment is used for the purpose of surface modification and ash removal. The performance of the prepared activated carbon in DCFC is evaluated in a self‐built DCFC anode apparatus. The results show that the BET surface area of activated carbon reaches 1240 m²/g under the following conditions: activation temperature, 1173 K; activation time, 2 h; and impregnation ratio, 1. Electrical conductivity is well improved through the nickel catalyst while the amount of surface oxygen functional groups is increased and ash content is decreased through the HNO₃ treatment. When used as the fuel in the DCFC anode, the self‐made activated carbon exhibits predominant performance among all tested carbon fuels, including graphite, activated carbon fibre, etc. © 2011 Canadian Society for Chemical Engineering     

Carbon-air fuel cell without a reforming process

This paper describes a direct carbon-air fuel cell (DCFC) which uses a molten hydroxide electrolyte. In DCFCs, carbon is electrochemically directly oxidized to generate the power without a reforming process. Despite its compelling cost and performance advantages, the use of molten metal hydroxide electrolytes has been ignored by DCFC researches, primarily due to the potential lack of invariance of the molten hydroxide electrolyte caused by its reaction with carbon dioxide. This paper describes the electrochemistry of a patented medium-temperature DCFC based on molten hydroxide electrolyte, which overcomes the historical carbonate formation.To date, four successive generations of DCFC prototypes have been built and tested to demonstrate the technology, all using graphite rods as their fuel source. These cells all used a simple design in which the cell containers served as the air cathodes and successfully demonstrated delivering more than 40 A with the current density exceeding 250 mA/cm². The cathode is of non-porous structure made of an inexpensive Fe-Ti alloy, and gaseous oxygen is introduced into the cell by bubbling humid air through the electrolyte. Results obtained indicated that the cell operation was under a mixed Ohmic-mass transfer control. Anode and cathode reaction mechanisms are also discussed.     

Effect of temperature on the electrochemical oxidation of ash free coal and carbon in a direct carbon fuel cell

The present study proposes the application of ash-free coal (AFC) as a primary fuel in a direct carbon fuel cell (DCFC) based on a molten carbonate fuel cell (MCFC). AFC was produced by solvent extraction using microwave irradiation. The influence of AFC-to-carbonate ratio (3: 3, 3: 1, 3: 0 and 1: 3 g/g) on the DCFC performance at different temperatures (650, 750 and 850 oC) was systematically investigated with a coin-type cell. The performance of AFC was also compared with carbon and conventional hydrogen fuels. AFC without carbonate (AFC-to-carbonate ratio=3: 0 g/g) gave a comparable performance to other compositions, indicating that the gasification of AFC readily occurred without a carbonate catalyst at 850 oC. The ease of gasification of AFC led to a much higher performance than for carbon fuel, even at 650 oC, where carbon cannot be gasified with a carbonate catalyst.     

Electrochemical oxidation of carbon in a 62/38 mol % Li/K carbonate melt

The electrochemical gasification of coal to CO in a direct carbon fuel cell (DCFC) has thermodynamical advantages, including the conversion of heat into power at a reversible efficiency of 100%. Molten carbonate fuel cell (MCFC) technology may form the basis for constructing DCFC's. Here the electrochemical oxidation of carbon in a 62/38 mol % Li/K carbonate melt is studied using impedance spectroscopy (IS) and cyclic voltammetry (CV). A set of equilibria is introduced which fully describes the electrochemical equilibrium of the system. From IS it is shown that for temperatures lower than 700 °C, charge transfer is the slowest step, while at higher temperatures a second unidentified step also contributes significantly to the d.c. resistance of the electrode. The d.c. resistance is 100 to 220 cm² at 650 °C and 12 to 60 cm² at 750 °C, depending on the carbon surface roughness.     

煤基直接碳燃料电池硫处理工艺探索

煤炭是我国的主要能源,以燃烧煤为主的煤炭利用过程产生了大量的温室气体CO2、含硫化合物气体等。通过煤基直接碳燃料电池发电,理论热力学效率接近100%,而且可以实现CO2的零排放,是煤高效、低碳洁净利用的关键技术,其大规模推广应用却受到原煤含硫化合物引起的硫中毒的制约。通过对现有煤脱硫工艺进行分析,提出洗选→化学氧化→电化学氧化→离子液体萃取→溶剂萃取→高温固硫(PCESTO)阶段联合处理工艺对原煤进行脱硫处理,可以有效降低煤中硫含量,定向转化直接碳燃料电池中硫的存在形式,减少和消除硫对直接碳燃料电池电极的毒化作用。     

A carbon in molten carbonate anode model for a direct carbon fuel cell

The electrochemical oxidation of carbon at the anode of a direct carbon fuel cell (DCFC) includes charge transfer steps and chemical steps. A microstructural model of carbon particle is built, in which perfect graphene stacks are taken as the basic building blocks of carbon. A modified mechanism taking account of the irreversibility of the process and supposing that the electrochemical oxidation of carbon takes place only at the edges of the graphene sheets is proposed. A Tafel type overall rate equation is deduced along with expressions of exchange current density (j₀) and activation polarization (η_act). The performance of carbon black and graphite as the fuel of DCFC is examined. It has been found that j₀ is in the range of 0.10-6.12 mA cm⁻² at 923-1123 K and η_act is in the range of 0.024-0.28 V at 923-1123 K with current density in 10-120 mA cm⁻². Analysis of the j₀, η_act values and the product composition reveals that the charge transfer steps as well as the oxygen ion absorption steps are both important for the reaction rate. The activity of the carbon material with respect to atom location is introduced to the open circuit potential difference (OCP) calculation with Nernst equation.     

Gasification of bamboo carbon with molten alkali carbonates

Solid carbon can be used as a fuel in the direct carbon fuel cell (DCFC). The chemical oxidation of carbon with alkali carbonates was investigated in this work. Decreasing the weight ratio of carbon to carbonate from 5 g: 5 g to 5 g: 20 g had an insignificant effect on the amount and concentration of gases. However, changing the amounts from 5 g: 5 g to 20 g: 20 g tripled the total amount of gases produced with similar gas compositions. The gas compositions ranged from 62.2–67.5 mol% CO, 13.9–14.7 mol% H2, and 5.7–16.8 mol% CO₂ at 800 °C. Thus CO was the dominant gas species in the conditions. With increasing temperature, CO generation was activated, especially over 700 °C. The carbonate species did not affect carbon oxidation. Steam was supplied to the carbon and carbonate mixture at a fixed flow rate of N₂ or air. H₂ was the highest composition at both cases.