微生物燃料电池及其应用研究进展

简述了微生物燃料电池的发展简史和工作原理,介绍了微生物燃料电池阳极材料、阴极材料和膜材料等方面的发展现状,分析了近年来国内外对直接和间接微生物燃料电池的研究情况,并指出微生物燃料电池反应器为获取氢能开辟了新用途.     

微生物燃料电池阳极系统的最新研究进展

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.该文介绍了微生物燃料电池的工作原理和电子传递途径,并结合近期研究成果,重点评述了微生物燃料电池中阳极系统的研究状况,对阳极特性、产电微生物的种类、阳极生物膜驯化方式等三个方面进行了评价,提出了目前阳极研究中存在的问题以及未来的研究重点和方向.     

低电位泡沫石墨改性阳极及其在海底微生物燃料电池中的应用

泡沫石墨是一种新型阳极材料, 对其进行改性是提高海底微生物燃料电池性能的重要途径之一。本文研究了混酸改性泡沫石墨阳极及其电化学性能。研究表明:改性后泡沫石墨表面生成羟基、羧基等含氧官能团; 改性阳极接触角降低了24.5°, 润湿性提高, 有利于微生物附着; 交换电流密度达到6760.8 mA/m², 动力学活性提高了53.7倍。研究还发现改性后阳极电位降低了100 mV, 电池开路电位达到865 mV (未改性750 mV), 最大输出功率密度为358.1 mW/m², 提高了2.4倍。三个月放电测试显示, 改性阳极和电池具有相对稳定的性能。同时, 本文初步分析了改性后阳极动力学活性增加和电位降低的原因。该研究结果为构建高输出电压和功率的海底微生物燃料电池提供了依据。     

α-MoC在无介体微生物燃料电池阳极的应用研究

采用溶体法结合碳热还原法制备了碳化钼,用XRD表征了碳化钼的结构,用SEM观察了所制备碳化钼的形貌。使用循环伏安法和交流阻抗法测试了碳化钼的电催化性能。把制备的碳化钼用于无介体微生物燃料电池阳极,电池最大功率密度达到商业铂碳的92%,表现出优越的电催化性能和良好的生物相容性。因此α-MoC可望成为一种具有广泛应用前景的无介体微生物燃料电池阳极材料。     

海底微生物燃料电池聚吡咯/多壁碳纳米管复合改性阳极及电化学性能

以十二烷基苯磺酸钠(SDBS)为掺杂剂,氯化高铁为氧化剂,采用化学氧化法制备了聚吡咯/多壁碳纳米管(PPy/MWCNTs)复合材料,并以该复合材料制备海底微生物燃料电池的阳极,并测试了改性阳极及电池的电化学性能。研究表明,聚吡咯紧密包裹在MWCNTs表面,改性阳极最大交换电流密度0.66 m A/cm2,是未改性的3.6倍。改性电池的最大功率密度为408.8 m W/m2,是未改性电池的5倍多。改性电极的电容是赝电容和双电层电容协同作用的结果,显著提高了电子传递效率和抗极化性能。提出了一种阳极/生物膜界面电子传递的新机理。     

低温对海泥发电性能的影响

环境温度对海泥发电(海底微生物燃料电池)具有重要影响。本文进行了4℃环境与常规室温环境(25℃)电池性能对比试验,结果表明:4℃环境下电池阳极启动时间明显慢于室温(25℃),阴极启动几乎无影响。4℃条件电池内阻(1005Ω)高于室温条件(703Ω),室温电池最大输出功率密度比4℃环境升高10mW/m2,电流密度增加46.6 mA/m2。低温环境(4℃)可导致微生物活性降低,物质扩散速度变慢,进而导致其电池性能低于室温环境。此实验对实海环境下海底微生物燃料电池设计提供了指导,具有实际意义。     

Ni-YSZ阳极添加Ag对固体氧化物燃料电池性能影响

为研究在Ni-YSZ阳极添加银对固体氧化物燃料电池(SOFC)性能的影响,采用化学镀银法在电池阳极镀银,在750℃分别以氢气和甲烷为燃料气,测试电池的电化学性能,并用扫描电子显微镜对测试前后的阳极进行表征。结果表明,电池在阳极镀银后,极化电阻减小,放电性能和抗积碳能力提高。化学镀银法镀银10min的电池在750℃以氢气为燃料气时,最大功率密度为511.7 mW·cm-2,比未镀银电池增加31.8%,以甲烷为燃料气时,以200mA·cm-2恒流稳定运行24h后,有少量积碳,相比恒流前最大功率密度降低0.8%。     

微生物燃料电池分隔材料的研究新进展

微生物燃料电池技术利用环境友好的高活性微生物作催化剂,以降解水中有机污染物同步输出电能,受到了学术界和企业界的高度重视。如何提高微生物燃料电池的效能是目前研究的聚焦点,分隔材料的设计与选择直接影响了微生物燃料电池的整体性能。本文综述了微生物燃料电池中分隔材料研究的新进展,对比分析了不同新型分隔材料的特点、产电能力与污水处理效果及其待解决的问题,展望了微生物燃料电池分隔材料的发展方向。     

碳酸氢铵电化学氧化阳极对含油海底沉积物微生物燃料电池性能影响及其加速降解研究

制备了3种阳极(未改性阳极、氨水改性阳极、NH_4HCO_3电化学氧化改性阳极)组建海底沉积物微生物燃料电池(MSMFCs),探究阳极的不同氨改性方法对含油MSMFCs电化学性能和石油降解率的影响。结果表明,电化学氧化改性阳极的电容特性是未改性阳极组的1.78倍,并且其抗极化能力最强,交换电流密度为2.57×10~(-2)A·m~(-2),是未改性的5.00倍;由电化学氧化改性阳极组建的电池的最大输出功率密度是1.53×102m W·m~(-2),较空白组的增加3.56倍,且该电池阳极沉积物中石油的降解率是空白组的10.40倍,这是因为改性阳极表面连入了有利于微生物附着的酰胺基团和氨基基团,提高了电池电化学性能并加速了石油的降解。     

四氧化三钴/石墨复合改性阳极对海底沉积物微生物燃料电池电化学性能的影响

首次将四氧化三钴/石墨(Co_3O_4/G)复合材料用于海底沉积物微生物燃料电池(MSMFCs)阳极改性,并对阳极电化学性能和电池性能进行研究。结果表明,Co3O4/G复合改性阳极表面的微生物附着数量是空白组的6.1倍;其氧化还原电化学活性和电容特性分别是空白组的16.2倍和31.0倍;交换电流密度达到1.366×10-3m A·cm-2,电子转移动力学活性是空白组的215.6倍,且其抗极化能力最强;电荷转移电阻降至空白组的2/5,并且双电层电容和生物膜电容均得到增加;其组成电池的功率密度为735.1 m W/m2,是空白组电池的4.6倍。机理分析表明,Co_3O_4和石墨的协同作用使复合改性阳极的电容性能和电子转移速率得到提高。     

Evaluation of Al and Some of Its Alloys as Anode Materials vs γ-MnO2 as Cathode Material and Ore Produced γ-MnO2 vs Zn Anode in KOH Solution

In this study electrochemical performance of Al and some of its alloys (Al-Zn, Al-Mg and Al-Mn) anodes vs MnO2 cathode were carried out in alkaline solution. The results show that the Al-Zn alloy anode has the best cell capacity among the other alloys. Cell capacity values go in the order Al-Zn＞Al-Mg＞Al＞Al-Mn. This result is probably related to the nature of passive films formed on the surface of the alloys which examined by scanning electron microscopy (SEM). SEM morphologies of Al and its alloys showed coarse grains of passive films formed on the surface of these anode materials while Al-Mn morphology shows a needle-like structure.Electrolytic manganese dioxide (EMD) produced by electrodepositing on platinum anode from liquor resulting from reduction of low grade pyrolusite ore (β-MnO2) by sulfur slag was characterized as cathode in alkaline Zn-MnO2 batteries. Ore produced sample (EMD1) was performed well in comparison with EMD standard (EMD2) (commercial battery grade electrolytic manganese dioxide, TOSOH-Hellas GH-S). SEM morphology of Zn anode after cell reaction was carried out and showed that Zn anode has fine grains of passive film on its surface.     

Evaluation of Al and Some of Its Alloys as Anode Materials vs γ-MnO2 as Cathode Material and Ore Produced γ-MnO2 vs Zn Anode in KOH Solution

In this study electrochemical performance of Al and some of its alloys （Al-Zn, Al-rvlg and Al-rvln） anodes vs MnO2 cathode were carried out in alkaline solution. The results show that the Al-Zn alloy anode has the best cell capacity among the other alloys. Cell capacity values go in the order Al-Zn〉Al-Mg〉Al〉Al-Mn. This result is probably related to the nature of passive films formed on the surface of the alloys which examined by scanning electron microscopy （SEM）. SEM morphologies of Al and its alloys showed coarse grains of passive films formed on the surface of these anode materials while Al-Mn morphology shows a needle-like structure. Electrolytic manganese dioxide （EMD） produced by electrodepositing on platinum anode from liquor resulting from reduction of low grade pyrolusite ore （β-MnO2） by sulfur slag was characterized as cathode in alkaline Zn-MnO2 batteries. Ore produced sample （EMD1） was performed well in comparison with EMD standard （EMD2） （commercial battery grade electrolytic manganese dioxide, TOSOH-Hellas GH-S）. SEM morphology of Zn anode after cell reaction was carried out and showed that Zn anode has fine grains of passive film on its surface.     

Manganese recovery from secondary resources: a green process for carbothermal reduction and leaching of manganese bearing hazardous waste

During the hydrometallurgical extraction of zinc by electrowinning process, a hazardous solid waste called anode mud is generated. It contains large quantity of manganese oxides (55-80%) and lead dioxide (6-16%). Due to the presence of a large quantity of lead, the anode mud waste is considered hazardous and has to be disposed of in secure landfills, which is costly, wastes available manganese and valuable land resources. For recovery of manganese content of anode mud, a process comprising of carbothermal treatment using low density oil (LDO) followed by sulphuric acid leaching is developed.     

Recovery of valuable elements from spent Li-batteries

This work examines two recycling processes for spent Li/MnO₂ and Li-ion batteries. The anode, cathode and electrolyte (LiPF₆) were submitted to one of the following procedures: (a) calcination at 500 °C (5 h) followed by solvent extraction to recover lithium salts (fluoride, phosphate) in good yield (90 wt%). The residual solid was treated with H₂SO₄ containing H₂O₂ and on evaporation gave high purity grade cobalt or manganese sulfate; (b) fusion with KHSO₄ (500 °C, 5 h). The resulting aqueous solution was added dropwise to a solution of NaOH, giving cobalt or manganese as impure precipitate. Addition of KF precipitated high purity grade LiF in moderate yield (50 wt%). The final aqueous solution on treatment with calcium sulfate precipitated the corresponding phosphate and fluoride salts.     

PEMFC catalyst layers: the role of micropores and mesopores on water sorption and fuel cell activity

The effects of carbon microstructure and ionomer loading on water vapor sorption and retention in catalyst layers (CLs) of PEM fuel cells are investigated using dynamic vapor sorption. Catalyst layers based on Ketjen Black and Vulcan XC-72 carbon blacks, which possess distinctly different surface areas, pore volumes, and microporosities, are studied. It is found that pores <20 nm diameter facilitate water uptake by capillary condensation in the intermediate range of relative humidities. A broad pore size distribution (PSD) is found to enhance water retention in Ketjen Black-based CLs whereas the narrower mesoporous PSD of Vulcan CLs is shown to have an enhanced water repelling action. Water vapor sorption and retention properties of CLs are correlated to electrochemical properties and fuel cell performance. Water sorption enhances electrochemical properties such as the electrochemically active surface area (ESA), double layer capacitance and proton conductivity, particularly when the ionomer content is very low. The hydrophilic properties of a CL on the anode and the cathode are adjusted by choosing the PSD of carbon and the ionomer content. It is shown that a reduction of ionomer content on either cathode or anode of an MEA does not necessarily have a significant detrimental effect on the MEA performance compared to the standard 30 wt % ionomer MEA. Under operation in air and high relative humidity, a cathode with a narrow pore size distribution and low ionomer content is shown to be beneficial due to its low water retention properties. In dry operating conditions, adequate ionomer content on the cathode is crucial, whereas it can be reduced on the anode without a significant impact on fuel cell performance.     

乳化炸药爆炸合成锂锰氧化物的实验研究

正极材料在锂离子电池成本中约占40%以上,锰酸锂被认为是目前最具发展前景的锂离子电池的正极材料。本文尝试以硝酸锂和硝酸锰作为氧化剂制备乳化炸药,通过乳化炸药爆炸合成锂锰氧化物,爆炸产物(锂锰氧化物)用X射线衍射(XRD)和TEM(透射电子显微镜)测试分析后得到验证。     

水热法制备尖晶石LiMn2O4正极材料的研究进展

介绍了近年来国内外有关水热法合成锂离子电池正极材料尖晶石LiMn2O4的研究工作,从锰源的选取对尖晶石锂锰氧化物的水热制备方法中存在的优缺点进行了比较和评述。对今后LiMn2O4水热合成研究以及发展方向等方面做了阐述。     

锌电沉积用Al/ Pb-Ag-Sn阳极的电化学性能研究

采用电沉积的方法在铝基体表面制备Pb-0.8%Ag-0.1%Sn复合阳极材料,并应用于电解锌中.研究了电沉积Pb-0.8%Ag-0.1%Sn复合阳极材料和电沉积Pb-0.8%Ag阳极材料及铸造Pb-0.8%Ag阳极材料在Zn SO4-H2SO4体系下极化24 h后的电化学性能,同时利用X射线衍射仪和扫描电镜分别分析三种阳极材料的相组成及观察三种阳极材料的微观形貌.结果显示:电沉积Pb-0.8%Ag-0.1%Sn复合阳极材料电催化性能和耐腐蚀性能比电沉积Pb-0.8%Ag复合阳极材料及铸造Pb-0.8%Ag阳极材料好.X-射线衍射图显示,对应的Pb-0.8%Ag-0.1%Sn阳极表面上β-Pb O2(101)和Pb Ox(1x2)(122)的衍射峰强度最强,说明Pb-0.8%Ag-0.1%Sn阳极表面的导电性优于另外两种阳极.扫描电镜图像显示Pb-0.8%Ag-0.1%Sn复合阳极材料表面形貌更加致密均匀.     

Performance of Ni/ScSZ cermet anode modified by coating with Gd0.2Ce0.8O2 for a SOFC

A Ni/scandia-stabilized zirconia (ScSZ) cermet anode was modified by coating with nano-sized gadolinium-doped ceria (GDC, Gd_0.2Ce_0.8O₂) within the pores of the anode for a solid oxide fuel cell (SOFC). X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed in the anode characterizations. Open circuit voltages (OCVs) increased from 1.027 to 1.078 V, and the maximum power densities increased from 238 to 825 mW/cm², as the operating temperature of a SOFC with 2.0 wt.%GDC-coated Ni/ScSZ anode was increased from 700 to 850 °C in humidified hydrogen. The coating of nano-sized Gd_0.2Ce_0.8O₂ particle within the pores of the porous Ni/ScSZ anode significantly improved the performance of anode supported cell. Electrochemical impedance spectra (EIS) illustrated that the cell with Ni/ScSZ anode exhibited far greater impedances than the cell with 2.0 wt.%GDC-coated Ni/ScSZ anode. Consequently, 2.0 wt.%GDC-coated Ni/ScSZ anode could be used as a novel anode material for a SOFC due to better electrochemical performance.