Innovative application of nanographene into microfluidic fuel cell electrolyte with enhanced chip cooling and energy harvesting

Microfluidic fuel cell (MFC) represents a novel technology for chip cooling and energy harvesting at the same time. By flowing electrolytes on chip surface, the waste heat can be efficiently removed, while the elevated electrolyte temperature can boost the fuel cell power output. To further improve its efficacy, this work introduces nanographene into its electrolyte for the first time, leading to an innovative nanofluid-enhanced MFC. Integrated with a heat simulation chip operated at 8.6 W/cm 2 , this novel technology achieves 20.6% higher peak power density and 14.2% lower chip surface temperature than the conventional MFC, proving nanographene's positive role in heat transfer enhancement and minimum negative impact on the fuel cell system. Moreover, starch is confirmed to be a suitable dispersant for this nanofluid electrolyte with excellent dispersion durability of more than 14 days as well as negligible fouling effect to the catalytic surface. Furthermore, the high physiochemical stability of nanographene under the combined thermal-mechanical-chemical-electrical stress is strongly proved, guaranteeing its high recycling capability so as to minimize the cost penalty.