A Passive Fuel Cell Fed with an Electrically Rechargeable Liquid Fuel

Abstract

Passive fuel cells, using diffusion and natural convection for fuel delivery, are regarded as promising candidates for powering portable devices including mobile phones and laptops. However, the performance of passive fuel cells which employ typical liquid alcohol fuels are still limited, which thereby greatly hampered their commercialization progress. Recently, a novel concept named the electrically rechargeable liquid fuel (e-fuel), with its rechargeability, cost-effectiveness, and superior reactivity, has attracted increasing attention. In this study, a passive fuel cell using the liquid e-fuel and the ambient air for electricity production is designed and fabricated. This passive fuel cell is demonstrated to achieve a peak power density of 116.2 mW cm −2 along with a stable operation for over 350 h, exhibiting great prospect for future applications.

Recent Advances in Anode Electrocatalysts for Direct Formic Acid Fuel Cells – Part I – Fundamentals and Pd Based Catalysts

“…It also indicated that palladium catalyst had high activity for formic acid oxidation at very low anode potential. The cell voltage was recorded to be well above 0.8 V. R.I Masel et al, also reported that the current density of the cell increased to 0.63 A, on using Palladium Black Anode as the catalyst, which was 200 times higher, when using a Platinum Catalyst at 0.4 V. The CV [313] (Reproduced with permission from reference 315, American Chemical Society, 2021) measurements carried out for palladium Black indicated a big anodic oxidation peak at 0.3 V. It was also reported that, on operating the DFAFC at 50°C, a maximum power density of 375 mW/cm 2 was achieved. [311] Kenis et al reported the performance output of a Si-Based DFAFC, where the fuel and oxidants are fed to the electrodes in a passive way, that is the liquid formic acid is in contact with the anodic part (Pd or Pt Catalyst) of MEA and on the other side, quiescent air is fed to the cathode (Pt Catalyst) which is more of an air breather setup.…”

“…Figure 13. (a) Working principle (b) Hardware components (c) Fabrication of a of a passive fuel cell[313] (Reproduced with permission from reference 315, American Chemical Society, 2021)…”

Manipulation of Electrode Composition for Effective Water Management in Fuel Cells Fed with an Electrically Rechargeable Liquid Fuel

“…During the test, the e-fuel was delivered to the anode by a peristaltic pump at a flow rate of 60 mL min –1 from a tank of 120 mL e-fuel, while pure oxygen was fed to the cathode at a flow rate of 10 sccm. The polarization curve tests were conducted using other homemade active − and passive fuel cells, as reported before, both of which have an active area of 2.0*2.0 cm 2 . For the active fuel cell, the e-fuel and the oxygen were fed into the cell at 60 mL min –1 and 10 sccm, respectively.…”

“…For the active fuel cell, the e-fuel and the oxygen were fed into the cell at 60 mL min –1 and 10 sccm, respectively. While for the passive fuel cell, a current collector with an open ratio of 70% was adopted . Both cells used 20 mL of e-fuel during the tests.…”

“…Recently, a novel fuel cell using the electrically rechargeable fuel (e-fuel) for power generation has been demonstrated. , The e-fuel can be made of a wide range of electroactive materials. In our previous studies, we developed a liquid e-fuel cell employing vanadium-based e-fuel and oxygen as reactants − and demonstrated its power generation capability under different operating conditions. While the cell is proved to exhibit a substantially improved performance that exceeds other conventional direct alcohol fuel cells, it is found that the water generated at the cathode during the cell operation due to the oxygen reduction reaction could lead to a water flooding problem .…”