Preparation of CoNi‐LDH‐Modified Polypropylene‐Based Carbon Fiber Membranes for Flexible Supercapacitors

ABSTRACT The rapid development of flexible electronic devices has placed higher demands on the development of high‐performance flexible supercapacitors. In this work, a safe and simple method was developed to prepare cobalt–nickel layered double hydroxide (CoNi‐LDH) flexible electrodes. Metal–organic framework (MOF)‐derived CoNi‐LDH was successfully grown on the surface of polypropylene nonwoven flexible carbon fiber membranes through plasma oxidation treatment, grafting of cobalt‐based MOFs, and room‐temperature etching in Ni 2+ solution. The prepared flexible modified carbon fiber membrane (CPO‐CoNi‐40‐0.5) has good mechanical properties with a tensile strength of 159.26 ± 63.03 kPa. In addition, the CPO‐CoNi‐40‐0.5 electrode has a high specific capacitance of 580 F g −1 at 1 A g −1 . The assembled supercapacitor maintains 99% of the initial specific capacity after 7000 cycles and 98% of the initial specific capacity when it is folded at 90°, showing excellent long cycle stability and bending resistance. This paper provides a new way to promote the development of high‐performance and low‐cost flexible electrodes.