Understanding the performance degradation and recovery of passive direct ethanol fuel cell

Faculty of Science, Energy and Environment, King Mongkut’s University of Technology North Bangkok, Rayong Campus, Rayong, 21120, Thailand

^* Corresponding author: panuwat.e@sciee.kmutnb.ac.th

Abstract

In developing a fuel cell, one of the major issues that obstruct the commercialization of fuel cells is cell degradation. Meanwhile, the recovery process is an important factor to upgrade the performance and durability of fuel cell system. In this work, a passive direct ethanol fuel cell (DEFC) recovered from the unused aged cell was investigated. The hydrogen evolution method was applied for recovering the cell performance. Electrochemical tools including cell polarization, anode polarization, electrochemical impedance spectroscopy (EIS), ethanol crossover measurement, and chronoamperometry were conducted to examine the activation phenomenon. The polarization curve of the fresh membrane electrode assembly (MEA) was obviously superior to the aged one. The maximum power density was decreased from 1.10 to 0.06 mW·cm^-2 reaching an approximate 95% decrement after keeping the cell for 1 year. The polarization curve of the MEA after conducting hydrogen evolution was better than that before. The maximum power density was enhanced from 0.06 to 0.07 mW·cm^-2 presenting an approximate 16.67% increment after recovering the cell. The MEA after the recovery process could reduce ohmic resistance by 67.40% indicating the enhancement of ionic and electronic conductivity and could improve kinetic reaction at the electrode. In conclusion, the recovery process would be helpful for the unused aged cell to improve the performance shortly.