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.
Keywords: E-fuel; current collector design; hydrogen evolution; long-term stability; passive fuel cell; power density.