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[Display omitted] The flexible and self-healing supercapacitors (SCs) are considered to be promising smart energy storage devices. Nevertheless, the SCs integrated with flexibility, lightweight, pattern editability, self-healing capabilities and desirable electrochemical properties remain a challenge. Herein, an all-in-one self-healing SC fabricated with the free-standing hybrid film (TCMP) composed of the 2,2,6,6-tetramethylpiperidin-1-yloxy-oxidized cellulose nanofibers (TOCNs) carried carbon nanotubes (CNTs), manganese dioxide (MnO 2) and polyaniline (PANI) as the electrode, polyvinyl alcohol/sulfuric acid (PVA/H 2 SO 4) gel as the electrolyte and dynamically cross-linked cellulose nanofibers/PVA/sodium tetraborate decahydrate (CNF/PB) hydrogel as the self-healing electrode matrix is developed. The TCMP film electrodes are fabricated through a facile in-situ polymerization of MnO 2 and PANI in TOCNs-dispersed CNTs composite networks, exhibiting lightweight, high electrical conductivity, flexibility, pattern editability and excellent electrochemical properties. Benefited from the hierarchically porous structure and high mechanical properties of TOCNs, excellent electrical conductivity of CNTs and the desirable synergistic effect of pseudocapacitance induced by MnO 2 and PANI, the assembled SC with an interdigital structure demonstrated a high areal capacitance of 1108 mF cm−2 at 2 mA cm−2, large areal energy density of 153.7 μWh cm−2 at 1101.7 μW cm−2. A satisfactory bending cycle performance (capacitance retention up to 95 % after 200 bending deformations) and self-healing characteristics (∼90 % capacitance retention after 10 cut/repair cycles) are demonstrated for the TCMP-based symmetric SC, delivering a feasible strategy for electrochemical energy storage devices with excellent performance, designable patterns and desirable safe lifespan. [ABSTRACT FROM AUTHOR]

Nowadays, electromagnetic pollution caused by the development of communication technology and electronic equipment has become an urgent problem to be solved. It is an effective solution to design high-performance electromagnetic wave absorption (EWA) materials with wide-band and powerful absorption characteristics for electromagnetic protection. In this work, a multi-scale MXene/carbon nanotube@Fe 3 O 4 composite material with a heterogeneous structure was synthesized by a solvothermal method, and the high/low-frequency EWA operating bands were adjusted by component regulation. The composite material performed excellent EWA performances based on the synergistic effect of polarization loss, conductive and magnetic loss, and three-dimensional heterointerfaces. Its minimum reflection loss reached − 59.95 dB with an effective absorption bandwidth of 4.7 GHz (13.3–18 GHz), which basically covered the Ku band. Therefore, this feasible scheme is expected to provide an effective strategy for controlling military and civil electromagnetic pollution. [Display omitted] • A facile preparation method of MXene-based multiscale composites was proposed. • Military/civil EWA operating frequency bands were adjusted by component regulation. • A superior RL min value of − 59.95 dB was obtained based on complex loss mechanisms. [ABSTRACT FROM AUTHOR]