Performance of polyacrylonitrile-carbon nanotubes composite on carbon cloth as electrode material for microbial fuel cells

The performance of carbon nanotubes composite-modified carbon cloth electrodes in two-chambered microbial fuel cell (MFC) was investigated. The electrode modified with polyacrylonitrile-carbon nanotubes (PAN-CNTs) composite showed better electrochemical performance than that of plain carbon cloth. The MFC with the composite-modified anode containing 5 mg/cm2 PAN-CNTs exhibited a maximum power density of 480 mW/m2.     

Fenton试剂改性海底生物燃料电池阳极及电化学性能

阳极材料直接影响海底生物燃料电池的性能。本文采用一种新型改性试剂—Fenton试剂对石墨阳极进行改性处理。结果表明,改性后电极表面主要引入了羟基和羰基,接触角从82°减小到48°,亲水性明显提高。塔菲尔曲线显示,改性前后交换电流密度分别为0.05 A/m2、0.17 A/m2,电极的动力学活性显著增加,提高了两倍之多。改性和未改性电池的最大输出功率密度分别为33.21 mW/m2、20.27 mW/m2,提高了64%。这是由于阳极表面处理后引入的羟基和羰基充当了电子转移介体,明显提高了电极反应动力学活性,增加了阳极表面细菌吸附数量,加速了阳极反应,提高了电池性能。该类高性能阳极材料可望用于海底生物燃料电池的开发。     

海底微生物燃料电池阳极邻苯二酚紫修饰及电化学性能

为了提高海底微生物燃料电池(BMFC)的功率,尝试利用邻苯二酚紫(PCV)修饰电池阳极,分析研究其电化学性能.结果表明,改性阳极表面的接触角由129.1°减小到了63.3°,亲水性增加.表面附着可培养异氧细菌数由6.8×105/cm2增加到1.6×106/cm2,数量提高1倍.改性阳极具有很好的抗极化性能,交换电流密度...     

SnO2 nanoparticles distributed on multi-walled carbon nanotubes and ball-milled graphite as anode materials of lithium ion batteries

SnO2 nanoparticles were supported on ball-milled graphite (BMG) or carbon nanotubes (CNTs) using a chemical reduction method with ethylene glycol, and the electrochemical properties of the nanocomposites were evaluated as anode active materials of lithium-ion batteries. The BMG and CNTs contributed to an increase in both the capacity enhancement and cyclic stability compared to that of commercial graphite. In particular, the mixture electrode of SnO2/BMG:SnO2/CNT = 3:1 (in weight ratio) showed higher performance in the reversible capacity and cyclic stability than did the SnO2/BMG and SnO2/CNT electrodes. This might be resulted from the network formation for excellent electronic path by CNT distributed on SnO2/BMG composites.     

A Mesoporous Tungsten Oxynitride Nanofibers/Graphite Felt Composite Electrode with High Catalytic Activity for the Cathode in Zn-Br Flow Battery

High electrochemical polarization during a redox reaction in the electrode of aqueous zinc–bromine flow batteries largely limits its practical implementation as an effective energy storage system. This study demonstrates a rationally-designed composite electrode that exhibits a lower electrochemical polarization by providing a higher number of catalytically-active sites for faster bromine reaction, compared to a conventional graphite felt cathode. The composite electrode is composed of electrically-conductive graphite felt (GF) and highly active mesoporous tungsten oxynitride nanofibers (mWONNFs) that are prepared by electrospinning and simple heat treatments. Addition of the 1D mWONNFs to porous GF produces a web-like structure that significantly facilitates the reaction kinetics and ion diffusion. The cell performance achieves in this study demonstrated high energy efficiencies of 89% and 80% at current densities of 20 and 80 mA cm⁻², respectively. Furthermore, the cell can also be operated at a very high current density of 160 mA cm⁻², demonstrating an energy efficiency of 62%. These results demonstrate the effectiveness of the mWONNF/GF composite as the electrode material in zinc–bromine flow batteries.     

Enhancing simultaneous electricity production and reduction of sewage sludge in two-chamber MFC by aerobic sludge digestion and sludge pretreatments

Batch tests were conducted to enhancing simultaneous electricity production and reduction of sewage sludge in two-chamber MFC by aerobic sludge digestion in cathode chamber and sludge pretreatments (sterilization and base pretreatment) prior to sludge addition to anode chamber, respectively. During the stable stage, The voltage outputs and power densities of MFC increased from 0.28-0.31 V to 17.3-21.2 mW/m(2) to 0.41-0.43 V and 36.8-40.1 mW/m(2), respectively, when aerobic sludge digestion occurred in the cathode chamber. When the sludge added to the anode chamber was sterilized or base pretreated, the voltage outputs and power densities of MFC increased from 0.30-0.32 V and 19.9-22.6 mW/m(2) (raw sludge) to 0.34-0.36 V and 25.5-28.6 mW/m(2) (sterilized sludge), 0.41-0.43 V and 37.1-40.8 mW/m(2) (base pretreated sludge), respectively. At the end of the test, the total suspended solids (TSS) and volatile suspended solids (VSS) reduction of sludge in the anode chambers increased from 33.9% and 36.8% to 34.5% and 38.7% with aerobic sludge digestion in the cathode chamber, respectively; while, those (TSS and VSS reduction) with sludge pretreatments prior to the sludge addition to the anode chambers increased from 25.1% and 22.8% (raw sludge) to 32.8% and 34.6% (sterilized sludge), and 25.5% and 26.7% (base pretreated sludge), respectively. The experimental results illuminated both aerobic sludge digestion in the cathode chamber and sludge pretreatments (sterilization and base pretreatment) prior to sludge addition to the anode chamber could enhance simultaneous electricity production from sludge and sludge reduction.     

Architecture engineering of hierarchically porous chitosan/vacuum-stripped graphene scaffold as bioanode for high performance microbial fuel cell

The bioanode is the defining feature of microbial fuel cell (MFC) technology and often limits its performance. In the current work, we report the engineering of a novel hierarchically porous architecture as an efficient bioanode, consisting of biocompatible chitosan and vacuum-stripped graphene (CHI/VSG). With the hierarchical pores and unique VSG, an optimized bioanode delivered a remarkable maximum power density of 1530 mW m(-2) in a mediator-less MFC, 78 times higher than a carbon cloth anode.     

甲硫氨酸沉积物和电化学沉积聚噻吩改性阳极对海底微生物燃料电池电化学性能的影响

使用电沉积的方法制备导电聚噻吩修饰的碳毡及在沉积物中添加甲硫氨酸组成一种新型双改性阳极,以此构建海底沉积物微生物燃料电池,并对阳极的电化学性能和电池性能进行测试。结果表明,双改性阳极表面微生物的数量为空白组的11.30倍,生物膜电容是空白组的1.4倍,说明双改性阳极提高了微生物的数量;双改性阳极循环伏安电容量(302.6 F/cm~2)是空白组(38.20 F/cm~2)的8.0倍,峰电流密度为5.980 A/m~2,交换电流密度(48.29×10~(-3)m A/cm~2)是空白组(0.073 7×10-3m A/cm~2)的651.3倍,说明双改性组的氧化还原电化学活性、抗极化能力和电子转移动力学活性显著提高;双改性电池的输出功率(190.6 m W/m~2)是空白组(71.8 m W/m~2)的2.7倍,说明双改性方法提高了电池阳极的电化学性能和电池性能。     

碳纳米管与石墨烯协同改性天然石墨及其电化学性能

以碳纳米管和氧化石墨烯为原料,二者按5∶3混合超声分散再高温还原制备碳纳米管/石墨烯/天然石墨(CNTs/rGO/NG)锂离子复合负极材料。采用扫描电镜(SEM)、X射线衍射(XRD)、红外光谱(FTIR)和电化学测试等分析技术对复合材料的形貌、结构、电化学进行表征。结果表明:石墨烯和碳纳米管在天然石墨表面形成三维立体网络结构。与纯天然石墨相比,CNTs/rGO/NG复合材料具有良好的倍率性能和循环寿命,在0.1C时首次放电比容量为479mAh/g,可逆容量达473mAh/g,循环100次后容量为439.5mAh/g,容量保持率为92%,在0.5,1,5C不同电流倍率时容量依次为457,433,394mAh/g。     

樟脑磺酸掺杂聚苯胺复合阳极在海底微生物燃料电池中的应用

制备了一种樟脑磺酸掺杂聚苯胺(PANI-(D-CSA))新型复合阳极,研究了其最佳配比,并在海底微生物燃料电池(BMFC)中测定其电化学性能.采用XRD衍射、热失重对聚苯胺阳极材料进行了表征.结构分析表明,PANI-(D-CSA)为部分结晶,热稳定性较好.性能测试表明,PANI-(D-CSA)质量分数为50%时复合阳极...     

纳米管协同碳纳米管导电纸对石墨负极性能的影响

以碳纳米管(Multi-walled carbon nanotubes)为导电剂,协同以碳纳米管和纸纤维复合成的CNTs导电纸为集流体,对石墨负极进行电化学改性。石墨化处理碳纳米管作为负极的添加相,采用XRD、SEM和TGA对其分析。结果表明,对比单纯的石墨/铜箔负极,掺杂0.8%(质量分数)石墨化碳纳米管的石墨/铜箔负极,电池比容量由304mAh/g变为308mAh/g,相差不大,但循环效率由86%升至92%;使用CNTs导电纸做集流体时,掺杂0.8%(质量分数)石墨化碳纳米管的石墨/CNTs导电纸负极,比容量由308mAh/g升至401mAh/g,提高30%,循环效率由92%升至95%,提高3%。说明碳纳米管协同CNTs导电纸对石墨负极具有积极的改性意义。     

Hydrogen Storage Alloy and Carbon Nanotubes Mixed Catalyst in a Direct Borohydride Fuel Cell

In this study, carbon nanotubes (CNTs) were mixed with AB5-type hydrogen storage alloy (HSA), as catalyst for an anode in a direct borohydride fuel cell (DBFC). As comparision, a series of traditional carbon materials, such as acetylene black, Vulcan XC-72R, and super activated carbon (SAC) were also employed. Electrochemical measurements showed that the electrocatalytic activity of HSA was improved greatly by CNTs. The current density of the DBFC employing the HSA/CNTs catalytic anode could reach 1550 mA·cm-2 (at -0.6 V vs the Hg/HgO electrode) and the maximum power density of 65 mW·cm-2 for this cell could be achieved at room temperature. Furthermore, the life time test lasting for 60 h showed that the cell displayed a good stability.     

Highly Stable Vanadium Redox‐Flow Battery Assisted by Redox‐Mediated Catalysis

With good operation flexibility and scalability, vanadium redox‐flow batteries (VRBs) stand out from various electrochemical energy storage (EES) technologies. However, traditional electrodes in VRBs, such as carbon and graphite felt with low electrochemical activities, impede the interfacial charge transfer processes and generate considerable overpotential loss, which significantly decrease the energy and voltage efficiencies of VRBs. Herein, by using a facile electrodeposition technique, Prussian blue/carbon felt (PB/CF) composite electrodes with high electrochemical activity for VRBs are successfully fabricated. The PB/CF electrode exhibits excellent electrochemical activity toward VO²⁺/VO₂⁺ redox couple in VRB with an average cell voltage efficiency (VE) of 90% and an energy efficiency (EE) of 88% at 100 mA cm^?2. In addition, due to the uniformly distributed PB particles that are strongly bound to the surface of carbon fibers in CF, VRBs with the PB/CF electrodes show much better long‐term stabilities compared with the pristine CF‐based battery due to the redox‐mediated catalysis. A VRB stack consisting of three single cells (16 cm²) is also constructed to assess the reliability of the redox‐mediated PB/CF electrodes for large‐scale application. The facile technique for the high‐performance electrode with redox‐mediated reaction is expected to shed new light on commercial electrode design for VRBs.     

电氧化过程中活性炭纤维阳极本身的性能评价

以活性炭纤维毡为阳极,不锈钢片为阴极,在Na2SO4介质中用恒定的电流强度进行电解,一定时间后将活性炭纤维毡取出用蒸馏水冲洗干净,在110℃下干燥12h,在干燥器中冷却至室温后,进行称重和红外、比表面积及孔分布测试。同时,以石墨片为阳极进行对比实验。结果显示,在电化学氧化过程中,活性炭纤维阳极表面的含氧活性基团量增加;与石墨电极相比,活性炭纤维电极具有更好的抗氧化性能和更高的析氧电位。因此,在难降解有机物的电氧化处理过程中活性炭纤维毡比石墨片更适宜作阳极。     

电化学氧化改性石墨毡电极对VO2+/VO+2电对的催化活性

采用循环伏安和恒流充放电试验研究了电化学氧化改性石墨毡对VO2 /VO 2电对的催化活性,并利用XPS、FT-IR、SEM、BET对改性前后石墨毡碳纤维表面O/C、官能团变化、形貌和比表面积进行比较.结果表明,电化学处理后,石墨毡表面的O/C比例由0.085增加至0.15,增加的主要是COOH官能团.石墨毡碳纤维表面被刻蚀,比表面积有所增大.采用改性的石墨毡作为电极组装的全钒液流电池在50mA/cm2电流密度下,电压效率达75.99%,电流效率达96.79%,经多次循环性能稳定.电极活性的提高归因于碳纤维表面COOH官能团数目的增加和比表面积的增大.     

Vertically grown multiwalled carbon nanotube anode and nickel silicide integrated high performance microsized (1.25 μL) microbial fuel cell

Microbial fuel cells (MFCs) are an environmentally friendly method for water purification and self-sustained electricity generation using microorganisms. Microsized MFCs can also be a useful power source for lab-on-a-chip and similar integrated devices. We fabricated a 1.25 μL microsized MFC containing an anode of vertically aligned, forest type multiwalled carbon nanotubes (MWCNTs) with a nickel silicide (NiSi) contact area that produced 197 mA/m(2) of current density and 392 mW/m(3) of power density. The MWCNTs increased the anode surface-to-volume ratio, which improved the ability of the microorganisms to couple and transfer electrons to the anode. The use of nickel silicide also helped to boost the output current by providing a low resistance contact area to more efficiently shuttle electrons from the anode out of the device.     

Structure and electrochemical performance of ZnO/CNT composite as anode material for lithium-ion batteries

Metal oxides are well-known potential alternatives to graphite as anode materials of lithium-ion batteries, and they can deliver much higher reversible capacities than graphite even at high current densities. In this study, hexagonal disk-shaped ZnO are synthesized by a facile solution reaction of ZnCl₂ and its composite is prepared in the presence of carbon nanotubes (CNTs). The as prepared ZnO/CNT composite has been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, fourier transform-infrared spectroscopy and Rutherford backscattering spectroscopy. Electrochemical characterization by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic discharge/charge tests demonstrate that the conversion reactions in ZnO and ZnO/CNT electrodes enable reversible capacity of 478 and 602 mAh g^?1, respectively for up to 50 cycles. Our investigation highlights the importance of anchoring of small ZnO particles on CNTs for maximum utilization of electrochemically active ZnO and CNTs for energy storage application in lithium-ion batteries.     

Carbon nanotube (CNT)-based composites as electrode material for rechargeable Li-ion batteries: A review

The ever-increasing demands for higher energy density and higher power capacity of Li-ion secondary batteries have led to search for electrode materials whose capacities and performance are better than those available today. Carbon nanotubes (CNTs), because of their unique 1D tubular structure, high electrical and thermal conductivities and extremely large surface area, have been considered as ideal additive materials to improve the electrochemical characteristics of both the anode and cathode of Li-ion batteries with much enhanced energy conversion and storage capacities. Recent development of electrode materials for LIBs has been driven mainly by hybrid nanostructures consisting of Li storage compounds and CNTs. In this paper, recent advances are reviewed of the use of CNTs and the methodologies developed to synthesize CNT-based composites for electrode materials. The physical, transport and electrochemical behaviors of the electrodes made from composites containing CNTs are discussed. The electrochemical performance of LIBs affected by the presence of CNTs in terms of energy and power densities, rate capacity, cyclic life and safety are highlighted in comparison with those without or containing other types of carbonaceous materials. The challenges that remain in using CNTs and CNT-based composites, as well as the prospects for exploiting them in the future are discussed.     

Evaluation of Cathode Electrodes in Lithium-Ion Battery: Pitfalls and the Befitting Counter Electrode

Boosting energy density and reducing the cost of lithium-ion batteries are critical to accelerating their applications in transportation and grid energy storage. Battery design with increasing electrode thickness is an effective way to combine higher energy density and lower cost. However, the evaluation of electrodes with increased thickness is challenging and requires more attention. Here, some pitfalls are to be avoided and a reasonable evaluation strategy is provided for cathode electrodes regarding the choice of counter electrode. Though as the most common counter electrode, lithium metal anode is actually not suitable for evaluating cycling performance, which exhibits fast cell capacity decline, especially, in the case of areal capacity higher than 2 mAh cm⁻². Two commercial anode materials, graphite and Li₄Ti₅O₁₂ (LTO) as the potential alternatives, are systematically evaluated and compared, demonstrating LTO as the more suitable choice. The thick cathode electrode coupled with LTO exhibits excellent rate capability, stable cycling performance, and easy interpretation of charge/discharge profile. The relationship between cell balance and battery performance is further analyzed in detail. This strategy enables a reasonable evaluation of the cathode electrodes and advances the designing of thick electrode.     

Preparation of CdS doped carbon nanotubes and their electrochemical properties

A CdS doped carbon nanotube sol was synthesised by the sol-gel technique and applied to a titanium plate to synthesise a composite electrode. Energy dispersion X-ray spectroscopy and X-ray diffraction analysis confirmed that the electrodes contain CdS. Scanning electron microscopy revealed that the carbon nanotubes were uniformly dispersed on the surface of the plate. A two-chamber microbial fuel cell was constructed using the electrode as the anode, flexible graphite as the cathode and glucose solution as the substrate in the anode chamber. The effects of CdS dose, glucose concentration and temperature on the cell efficiency and organic degradation have been analysed. At 313 K, the two-chambered fuel cell possessed the optimum output voltage of 906 mV, with a power of 19·6 mW m^?2 and a removal rate of 81% for chemical oxygen demand in treatment of wastewater. The composite electrode was found to be stable and to perform reproducibly.