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High‐performance fibrous materials urgently desired for fabricating energy storage devices to power wearable textile electronics are expected excellent mechanical properties, improved output capacitance, and rapid charge/discharge capability; nevertheless, their contradictory requirements in material design impose immense challenges. Inspired by the robust structure of higher plants that evolve over millions of years, herein, an interfacial engineering strategy is proposed for synergizing the mechanical strength and electrochemical performance of Ti3C2TX MXene fibers by selecting aramid (Kevlar) nanofibers and borate ions (B) as the enhancers. The intercalation of Kevlar nanofibers endows the nascent wet‐spun MXene gel fibers with a high stretchable ratio through physical interaction (hydrogen bonds), greatly aligning the orientation of MXene nanosheets. B‐cross‐links introduce covalent bonds between MXene nanosheets, which together with hydrogen bonds significantly enhance fiber strength. More importantly, optimal ion transport kinetics is achieved by synergizing the inverse impacts of Kevlar nanofibers and B‐cross‐link on interlayer spacing, guaranteeing excellent electrochemical performances. Benefiting from their excellent mechanical, electrical, and electrochemical performances, borate (B)‐cross‐linked MXene/Kevlar fibers (MKB) are simultaneously adopted as fibrous electrodes and receiving antennae for asymmetric supercapacitors with wireless charging functions. The proposed strategy provides an avenue for designing high‐performance functional fibers for future wearable applications. [ABSTRACT FROM AUTHOR]

Rechargeable batteries are deemed as green and efficient energy storage systems and have drawn great attention during past decades. Despite the commercial applications of lithium‐ion batteries, the ever‐increasing demands for higher energy storage capability driven by the rapid development of portable/wearable electronics remain unsatisfied due to the low theoretical capacity of the commonly used graphite anode. Herein, a material design strategy by synergizing the merits of conversion‐type Co2V2O7 and intercalation‐based Ti3C2Tx MXene for efficient lithium‐ion storage is reported. The Co2V2O7@MXene hollow polyhedrons are synthesized by ion exchange, surface modification, and the subsequent electrostatic assembly. Benefiting from the high conductivity and mechanical robustness of the MXene sheath, the high theoretical capacity of Co2V2O7, and the unique hollow structure, the optimized hybrids deliver a high output capacity of 949.7 mAh g−1 at 0.1 A g−1, excellent rate capacity with 431.4 mAh g−1 retained at 5.0 A g−1, as well as outstanding cycling stability. [ABSTRACT FROM AUTHOR]

Despite great efforts that have been made to develop high performance carbonaceous materials via structure design for charge storage applications, constructing tubular architectures composed of hierarchically nanoscale building units is challenging due to the lack of suitable synthetic method. Herein, using zeolitic imidazolate framework‐8 (ZIF‐8) as the self‐template and electrospun polyacrylonitrile (PAN) nanofibers as the sacrificial core, hierarchically tubular architectures composed of hollow N‐doped carbon polyhedrons (T‐HNCPs) are successfully obtained. Due to its unique structural characteristics and the merit of N‐doping, the as‐prepared T‐HNCPs electrode with much open structure (average pore size of ≈2.38 nm and specific surface area of 1302.5 m2 g−1) exhibits improved specific gravimetric capacitances of 351.2 and 230.4 F g−1 at 1 and 20 A g−1 (corresponding to 65.6% retention), respectively, together with outstanding charge/discharge stability. [ABSTRACT FROM AUTHOR]

Ti3C2TX MXene with the merits of metallic conductivity, superhigh volumetric capacitance, and efficient absorption of the electromagnetic wave is considered a promising building block for fiber fabrication; nevertheless, the simultaneous improvement in electrochemical charge storage and electrical conductivity/thermal management is seldom achieved for MXene‐based fibers due to the contradictory in material design. Typically, aligned and densified packing of MXene fibers is highly desired for an enhanced intra‐/inter‐flake electron transport; however, the narrowed inter‐layer spacing restricts the kinetics of ion diffusion (the intercalation/de‐intercalation of electrolyte ions) and diminishes the accessible active sites for charge storage. Herein, the electron and ion transports of Ti3C2TX MXene fiber are synergized via a unique dot‐sheet heterostructure covalently bonded by Ti─C─Ti which provides the optimal inter‐layer spacing for rapid ion diffusion and enhances the intra‐/inter‐flake cross‐linking for fast electron transport. As a result, the obtained fiber offers an improved conductivity of 2405 S cm−1, a desirable capacitance of 1597 F cm−3, an impressive energy density of 19.8 mWh cm−3 for the assembled supercapacitor, superior Joule heating performance, and a photo‐thermal temperature. These remarkable attributes enable their practical applications in energy‐supply scenarios, such as powering LEDs and wearable thermal management. [ABSTRACT FROM AUTHOR]