Superior energy storage and stability realized in flexible carbon nanotube aerogel-metal organic framework based supercapacitor via interface engineering

Abstract

Our present study unveils a new carbon nanotube aerogel-metal organic framework free-standing electrode, showcasing exceptional dual functionality as an electrode and current collector. In the prepared electrode, an interface engineering between functionalized carbon nanotubes (FCNT) and metal-organic frameworks (MOF) leads to the excellent electrochemical performance of the supercapacitor. The carbon nanotube aerogel with its exceptional surface area and electrical conductivity, lays the foundation for lightning-fast charge transfer. Meanwhile, the metal-organic frameworks present at the interface, grant ions unbridled storage space contributing to efficient charge storage. The ulta-light-in-weight FCNT-MOF free-standing electrode exhibited an excellent specific capacitance of 465 F g−1 (116 mF cm−2) at 2 A g−1 with outstanding cyclic stability of 92 % after 6000 cycles. The flexible FCNT-MOF symmetric supercapacitor demonstrated a high energy density of 40.5 W h kg−1 at a power density of 1600 W kg−1. The simplified fabrication process, reduced active material requirements (0.25 mg cm−2), and enhanced performance make it an attractive option for supercapacitor application. Furthermore, the integration of this electrode design into supercapacitors holds great promise for portable electronics, electric vehicles, and renewable energy systems.