Optimization of a passive direct methanol fuel cell with different current collector materials

• Published in: Energy (Oxford) 2020-10, Vol.208, p.118394, Article 118394
• Main Authors: Braz, B.A., Oliveira, V.B., Pinto, A.M.F.R.
• Format: Article
• Language: English
• Subjects: Anodes; Cathodes; Circuits; Current collector materials; Durability; Efficiency; Electrochemical impedance spectroscopy; Electrochemistry; Electrode polarization; Fuel cells; Fuel technology; Maximum power density; Methanol; Methanol concentration; Optimization; Passive direct methanol fuel cell; Performance evaluation; Performance losses; Service life assessment; Spectroscopy; Stainless steel; Stainless steels; Titanium; Weight reduction
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2020.118394

Towards the introduction of passive direct methanol fuel cells in the market, it is mandatory to achieve an optimum balance between its cost, efficiency and durability. To achieve that and knowing that the current collectors are responsible for about 80% of these systems weight, different current collector materials were tested in the anode and cathode sides of a passive direct methanol fuel cell, towards a cost and weight reduction. The best configuration was used to assess the lifetime of the developed passive direct methanol fuel cell. The cell performance and lifetime was evaluated through polarization measurements and these results were explained under the light of the electrochemical impedance spectroscopy data. A major novelty of this study is the use of an innovative equivalent electric circuit that accurately describes a passive direct methanol fuel cell, which allowed the identification and quantification of the different performance losses that negatively affect these systems efficiency. The maximum power density of 5.23 mW/cm2 was achieved using Titanium as anode current collector and Stainless Steel as cathode current collector and a methanol concentration of 7 M. The durability tests showed a lifetime of 200 h and a loss of efficiency of 41%. •Different CC materials were tested in a pDMFC to achieve enhanced performances.•The pDMFC lifetime was evaluated though the voltage drop over the operation time.•The results were explained under the light of EIS measurements.•The best performance was achieved using Ti as anode CC and SS as cathode CC.•The maximum power density, 5.23 mW/cm2, was achieved with a concentration of 7 M.