Multiscale Structure Regulation Induced by Fluorine Coordination Enables High-Performance and Durable PEMFC
Jingsen Bai, Xingang Guan, Hong Qiang Qu, Liang Liang, Chunyu Ru, Xue Gong, Jin Zhao, Meiling Xiao, Changpeng Liu, Wei Xing
Abstract
The stability enhancement of metal–nitrogen–carbon (M–N–C) is often inevitably accompanied by a loss of activity. Additionally, during the long-term operation, the activity frequently declines due to water flooding effects, significantly reducing the lifetime of the membrane electrode assembly (MEA). Herein, fluorine (F)-doping was employed to bypass the activity–stability trade-off of Fe–N–C catalysts. F incorporation increases the metal dissolution energy and lowers the electron density of Fe–N 4 sites, improving both stability and catalytic activity. Besides, the hydrophobicity of F can improve water management performance within the MEA, markedly reducing oxygen transport resistance. As a result, the F-doped Fe–N–C cathode enables a high peak power density of 1.1 W cm –2, far exceeding the Fe–N–C counterpart (0.79 W cm –2 ). More importantly, 90% of the power density can be retained after 30000 cycles of accelerated stress testing, demonstrating huge application potential in fuel cells.