具有不同自由离子的离子交换膜对MFC性能的影响

Effects of Types of Ions in Ion Exchange Membranes on Microbial Fuel Cell Performance

将4种具有不同自由离子的离子交换膜,即阳离子交换膜的H+型(CEM-H)和Na+型(CEM-Na)、及阴离子交换膜的Cl-型(AEM-Cl)和OH-型(AEM-OH),作为分离膜应用于微生物燃料电池(MFC)。结果表明,4种膜的电导率呈顺序为CEM-H>CEM-Na>AEM-OH>AEM-Cl,与之相对应的MFC产电性能呈相同的顺序。采用CEM-H的MFC产电性能最好,最大功率密度可达899 m W/m2;同时膜性能的不同导致MFC的库伦效率、阳极p H等存在差异。电化学阻抗谱(EIS)研究表明,在电池运行过程中阴离子交换膜的污染造成了较大的内阻,严重影响了其MFC的产电性能。

Four different free ion of ion exchange membranes, namely cation exchange membranes with exchangeable ions of H^＋ （CEM-H） and Na^＋ （CEM- Na）, and anion exchangeable of Cl^- （AEM-Cl） and OH^- （AEM-OH） were used in microbial fuel cells （MFC） as separating membranes. The ion conductivity of the four membranes is in the order of CEM-H〉CEM-Na〉AEM-OH〉AEM-Cl, while the maximum output power of the corresponding MFC shows the same order. The MFC with CEM-H has the highest power density and the lowest internal resistance, the maximum power density reached 899 mW/m^2. The differences in the coulombic efficiency and pH of the solution in cathode chambers were also found in the four MFCs. The results from the electrochemical impedance spectra （EIS） showed that larger membrane resistances in the MFC with anion exchange membranes were due to the membrane fouling during the MFC operation.