Abstract: The output power and resistance were evaluated to investigate the effects of pH, substrate concentration, electrode spacing and electrolyte addition on the electricity generation of direct microbial fuel cell. The results showed that output power was much affected by pH. The optimal pH value was 7.5. The output power increased with the substrate concentration. It could be improved with the decrease of resistance as the electrode spacing decreased. When electrode spacing was decreased to 2 cm, the maximum power density was 700 mW/m2, the resistance 80 W, and the coulomb efficiency 7.7%. PBS as the electrolyte was much better than NaCl on power improvement. When PBS was 100 mmol/L, the maximum power density was 922 mW/m2, the resistance 70 W, and the coulomb efficiency 11.5%.

Key words: microbial fuel cell, influence factors, power density

摘要： 以输出功率和内阻为评价指标，考察了直接微生物燃料电池在间歇运行过程中pH值、底物浓度、电极间距和添加电解质对产电性能的影响. 结果表明，pH值对输出功率影响较大，最佳值为7.5；输出功率随底物浓度的增大而增大．减小电极间距能有效降低电池内阻，提高输出功率，当电极间距为2 cm时，最大功率密度为700 mW/m2，内阻为80 W，库仑效率为7.7%. 磷酸盐缓冲溶液作为电解质对功率提高的效果优于NaCl，其添加量为100 mmol/L时，最大功率密度达922 mW/m2，内阻为70 W，库仑效率为11.5%.

关键词: 微生物燃料电池, 影响因素, 功率密度