Design of a novel self-breathing micro fuel cell stack with a silicon membrane based on the demand for portable charging power sources

Abstract

This study proposes a portable mobile power supply with a self-breathing micro-proton exchange membrane fuel cells (µPEMFCs) stack as the core for the application of µPEMFCs in portable charging power supplies. A porous silicon membrane etched with hydrofluoric acid was used to conduct protons. A series array of single cells was formed on a single printed circuit board (PCB) board. Four PCB boards are connected by rotation to form a PEMFC stack, and the cavity enclosed by the PCB boards was used to store hydrogen. The effects of hydrogen pressure and ambient conditions on stack performance were analyzed, and the discharging time of the stack was investigated at standard charging powers of 5 V and 1 A. The results revealed that the heat dissipation method of the self-breathing stack limits the operating current density of the stack. To ensure that the stack temperature was within 60–80 °C, the current density should be controlled within 600–820 mA·cm−2. The mobile power supply designed in this study can satisfy the standard charging power requirements of 5 V and 1 A for electronic devices. When the hydrogen pressure was 3 atm, the discharging time of the mobile power supply was 420 s, and the discharging time could be extended by increasing the hydrogen pressure.