Sensing methanol concentration in direct methanol fuel cell with total harmonic distortion: Theory and application

详细信息	查看全文 | 推荐本文 |

• 作者：Qing Mao^a ; Ulrike Krewer^a ; ^b ; ^{u.krewer@tu-bs.de}
• 关键词：CSTR ; continuously stirred tank reactor ; DMFC ; direct methanol fuel cell ; THD ; total harmonic distortion ; EIS ; electrochemical impedance spectroscopy
• 刊名：Electrochimica Acta
• 出版年：2012
• 期刊代码：30_00134686
• 类别：ch
• 出版时间：30 April, 2012
• 卷：68
• 期：Complete
• 页码：60-68
• 文件大小：739 K

摘要

The nonlinear frequency response of a direct methanol fuel cell (DMFC) is studied by analyzing the total harmonic distortion (THD) spectra. The dependence of the THD spectra on methanol concentration and methanol oxidation kinetics is investigated by means of both simulation and experiment. Simulation using a continuous stirred tank reactor network model suggests that the methanol concentration profile in the anode has a strong impact on the THD spectra. The experimentally observed nonlinear behavior of the DMFC anode can be qualitatively reproduced with a model containing a three-step methanol oxidation mechanism with Kauranen-Frumkin/Temkin kinetics. Both experiment and simulation results show that THD value has a monotonic correlation with methanol concentration at certain frequencies and its sensitivity to concentration is improved with increased current amplitude. The monotonic relationship enables the THD to sense the methanol concentration level by the DMFC itself, which is of mayor interest for the portable application as an external sensor for the system can be omitted.