空气阴极生物燃料电池电化学性能

Electrochemical Performance of Microbial Fuel Cell with Air-Cathode

为提高生物燃料电池(MFC)的输出功率,降低内阻和有机物处理成本,实验以空气电极为阴极,泡沫镍(铁)为阳极,葡萄糖模拟废水为基质构建了直接空气阴极单室生物燃料电池,考察了电池的电化学性能.结果表明,MFC的开路电压为0.62V,内阻为33.8",最大输出功率为700mW·m-2(4146mW·m-3污水),电子回收率20%.放电曲线、循环伏安测试表明,MFC首次放电比容量和比能量分别为263mAh·g-1COD(化学需氧量)和77.3mWh·g-1COD,MFC充放电性能及稳定性均较好.电化学交流阻抗谱(EIS)分析表明,随放电时间的延长,电池阻抗增大,这是导致电池输出电压逐渐降低的原因之一.MFC运行8h,COD的去除率为56.5%,且COD的降解符合表观一级反应动力学.

In order to promote the energy output of microbial fuel cell （MFC）, reduce the internal resistance of MFC and the cost of processing organics, a direct-air cathode single-chamber microbial fuel cell was constructed by using air electrode as cathode, foamed nickel （ferrumiron） as anode and glucose as the anode fed. The results demonstrated that the open circuit voltage reached 0.62 V, the internal resistance of the cell was 33.8Ω, the maximum power density reached 700 mW·m^-2 （4146 mW·m^-3）, and the electron recovery was 20%. The discharge curve and cyclic voltammetry tests revealed that the first discharge capacity and energy density were 263 mAh·g^-1 COD （chemical oxygen demand） and 77.3 mWh·g^-1 COD, respectively. The charge-discharge performance and stability of MFC were pretty good. The electrochemical impedance spectroscopy analysis demonstrated that the cell impedance increased with the increase of discharge time, which was one of the reasons resulting in the decrease of output voltage. The degradation rate of COD （chemical oxygen demand） reached 56.5% after it operating for 8 h. The degradation of COD followed the first order reaction model.