微生物燃料电池生物阳极构造和产电性能研究

发布时间：2018-05-29 05:07

本文选题：阳极生物膜 + 阳极界面双电层电容　；参考：《浙江大学》2014年硕士论文

【摘要】：本文从阳极电阻、阳极材料电容和电池放电电压曲线三方面研究了微生物燃料电池生物阳极结构和产电性能性能。本文应用MATLAB数值模拟研究了大型化微生物燃料电池阳极电流导出形式对电池产电功率的影响,并通过实验结果验证计算结果的准确性。实验结果表明：不当的连接方式会造成21.7%的产电性能下降,结合计算和实验的结果推断在微生物燃料电池大型化的过程中,不当的连接造成的功率损失占阳极总功率损失的47.1%。本文还提出两种降低电阻造成产电功率损失的途径：(1)采用金属网作为集电体；(2)采用合理的高效的电流导出形式。通过改变阳极材料界面双电层电容研究了阳极材料电容对生物膜生长的影响。实验结果表明：增大阳极表面的双电层电容可显著提高电池的产电性能。用35目不锈钢网载超级电容器活性炭电极作为阳极的微生物燃料电池的功率密度最高可以达到585mWm-2。而载200nm粒径纳米活性炭作为阳极的电池功率密度只有31mWm-2。电池功率随着双电层电容的增大而增加,而与电极表面积相关度低。扫描电子显微镜的结果表明,阳极材料电容的增大使得阳极表面附着的微生物膜厚度、覆盖度增加,生物量的增加可能是功率密度随双电层电容增大而增加的原因。载超级电容器活性炭的电极的平均生物膜厚度为259urn,是在纳米活性碳电极生物膜厚度的203.1%。以补料式单室空气阴极微生物燃料电池首次研究了更换溶液之后电池电压的恢复过程和影响因素。研究发现,更换溶液后,以碳纤维材料为阳极的微生物燃料电池的放电电压曲线上出现两个电压平台(对应阳极电位分别为-250~-290mV和-390±10mV)。电压平台的现象主要和阳极有关,与阴极无关。碳刷阳极的电池第一个电压平台持续时间比碳纤维布阳极长。第一个电压平台受阳极表面特性的影响,其形成的原因可能是微生物燃料电池部分电流对阳极的双电层电容充电的过程；第二个电压平台与溶解氧有关,溶解氧增加会导致第二个电压平台的持续时间增加,并使得阳极性能变差。第二个电压平台的形成可能是阳极附近溶液从厌氧环境到微氧环境的变化造成的。
[Abstract]:In this paper, the structure and electrical properties of microbial fuel cell biological anode were studied from three aspects: anode resistance, anode capacitance and discharge voltage curve. In this paper, the influence of anodic current derived form on the output power of large scale microbial fuel cell is studied by MATLAB numerical simulation, and the accuracy of the calculated results is verified by the experimental results. The experimental results show that the power loss caused by improper connection will decrease by 21.7%. Combined with the calculation and experimental results, it is inferred that the power loss caused by improper connection accounts for 47.1% of the total anode power loss in the process of microbial fuel cell enlargement. This paper also proposes two ways to reduce the loss of electrical power caused by resistance: 1) the metal net is used as the collector and the current is derived in a reasonable and efficient way. The effect of anode capacitance on the growth of biofilm was studied by changing the double layer capacitance of anode interface. The experimental results show that increasing the double layer capacitance on the anode surface can significantly improve the electrical performance of the battery. The maximum power density of microbial fuel cell with 35 mesh stainless steel net-loaded activated carbon electrode as anode can reach 585 mWm-2. However, the power density of the anode with 200nm particle size nano-activated carbon was only 31 mWm-2. The power of the battery increases with the increase of the double layer capacitance, but the correlation with the electrode surface area is low. The results of scanning electron microscope (SEM) show that the increase of the capacitance of anode material can increase the thickness and coverage of the microbial film attached to the anode surface, and the increase of biomass may be the reason for the increase of power density with the increase of the double layer capacitance. The average biofilm thickness of the activated carbon electrode loaded with supercapacitor is 259 urn, which is 203.1 the thickness of the biofilm on the nanocrystalline activated carbon electrode. The recovery process and influencing factors of the battery voltage after changing solution were studied for the first time with the recharge single chamber air cathode microbial fuel cell. It was found that two voltage platforms appeared on the discharge voltage curve of microbial fuel cell with carbon fiber as anode after changing solution. The corresponding anode potentials were -250 ~ 290mV and -390 卤10mV respectively. The phenomenon of voltage platform is mainly related to anode and independent of cathode. Carbon brush anode battery first voltage platform duration longer than carbon fiber cloth anode. The first voltage platform is affected by the surface characteristics of the anode, which may be due to the charging process of the partial current of the microbial fuel cell to the anode's double-layer capacitance, and the second voltage platform is related to the dissolved oxygen. The increase of dissolved oxygen will increase the duration of the second voltage platform and make the anode performance worse. The formation of the second voltage platform may be caused by the change of anodic solution from anaerobic environment to micro-oxygen environment.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM911.4

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