Energizing Fuel Cells with an Electrically Rechargeable Liquid Fuel

Direct liquid fuel cells with high energy density and facile fuel storage have received increasing attention. Owing to the poor reactivity of conventional liquid fuels, they not only require noble metal catalysts for their oxidation but also exhibit limited performance. Here, we report a power-generation system, the direct liquid e-fuel cell, where “e-fuel” stands for “electrically rechargeable fuel.” This e-fuel cell consists of a catalyst-free graphite-felt anode and a conventional oxygen cathode separated by a proton exchange membrane, producing a maximum current density of 750 mA cm−2, a peak power density of 293 mW cm−2, and an energy efficiency of 42.3% at room temperature, which is much higher than the performances achieved by conventional direct liquid fuel cells. This emerging technology, capable of fast recharging, could be a powerful, efficient, cost-effective, and durable power-generation device, showing great potential for commercialization in the fuel cell electric vehicle industry.