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

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.