A Self-Charging Hybrid Electric Power Device with High Specific Energy and Power

Fabricating electrochemical power sources with both high specific energy and power is highly desirable but remains challenging. In this work, a kind of self-charging hybrid electric power device (HEPD) is created with an intrinsic combination of polymer electrolyte membrane fuel cells and supercapacitors on the electrode level. Because of the unique processes of electrocatalytic reactions boosted by the fast pseudocapacitive discharge, remarkably high specific energy (1550 Wh kg(-1)) and power (4080 W kg(-1)) can be delivered by the hybrid device. The working mechanism of HEPD is proposed and demonstrated by in situ characterization and extensive electrochemical investigations. The self-charging HEPD with its synergistic electrochemical processes will broaden the applications of electrochemical power sources.