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The cracks in flexible triboelectric nanogenerators (TENG) cannot naturally repair themselves during low‐temperature operation, which significantly restricts their practical applications. Yet, the development of elastomers capable of self‐repair at low temperatures has remained a formidable challenge. In this study, a dual dynamic cross‐linking network using multiple hydrogen bonds and β‐hydroxy esters is constructed to fabricate a fully bio‐based elastomer known as PLMBE. This elastomer can be stretched up to an impressive 1200% of its original length and possesses a remarkable autonomous self‐healing capability even under harsh conditions, including low temperatures (−10 °C, 12 h, with a 75% efficiency rate) and exposure to supercooled, high‐concentration saline (10% NaCl solution at −10 °C, 12 h, with a 64% efficiency rate). These remarkable properties are attributed to the elastomer's low glass transition temperature (Tg) of −30 °C and the abundance of hydrogen‐bonded supramolecular interactions. Importantly, this elastomer is highly suitable as a triboelectric layer for creating bio‐based TENG (Bio‐TENG). These results demonstrate that Bio‐TENG can achieve an impressive output power density of 2.4 W m−2, and the output voltage recovers up to 95% after self‐healing at −10 °C. Consequently, these bio‐based elastomers have promising applications in various fields, including energy storage devices. [ABSTRACT FROM AUTHOR]

Cobaltous oxide/nickel–iron oxide (Co3O4/NiFe2O4) hybrids were fabricated via a template-free hydrothermal route with cyclodextrin as a reactor and a further two-step annealing treatment in an air atmosphere. The hybrid is composed of many small nanoparticles with a particle size distribution range from 20 to 50 nm. The hybrid combined the advantages of Co3O4 and NiFe2O4 nanoparticles, presenting enhanced electrochemical properties than its single component. The Co3O4/NiFe2O4 (0.6:1) hybrid electrode exhibited the highest specific capacitance and great electrochemical cycle stability (over 90.7% of total capacitance at 2 A g−1 after 1000 cycles and still kept 84.6% at 5 A g−1 after 5000 cycles). This may be ascribed to the common contribution of each component, which not only provided good electronic conductivity for efficient charge transfer but also a stable structure for better ions diffusion. A Co3O4/NiFe2O4//AC asymmetry supercapacitor was assembled and manifested the highest energy density of 76.0 Wh kg−1 at a power density of 859.7 W kg−1 and still kept 37.3 Wh kg−1 at the highest power density of 6.0 kW kg−1. This work indicated that the Co3O4/NiFe2O4 hybrid should be a potential active material for the electrochemical application. [ABSTRACT FROM AUTHOR]

Abstract Herein, we report the rational design and synthesis of a novel flexible supercapacitor electrode consisting of lawn-like FeCo 2 S 4 hollow nanoneedle arrays (FeCo 2 S 4 HNNA) on electrospun carbon nanofiber (CNF) film via a two-step sulfidation method. In this work, the macroporous CNF film served as flexible/conducting substrate not only promotes the homogeneous distribution of FeCo 2 S 4 hollow nanoneedles, but also enhance the electrical conductivity of the composite film. Especially, the tip-welded FeCo 2 S 4 nanoneedles with unique interior channels and perpendicular orientation possess numerous accessible electroactive sites and short electrolyte transfer paths for efficient energy storage, and also buffer the drastic volume change during the repetitive charge-discharge process. As a result, prepared FeCo 2 S 4 HNNA/CNF composite electrode exhibits a high specific capacitance of 2476 F g−1 at 1 A g−1, and excellent capacitance retention of 93% after 5000 cycles, which is competitive among those previously reported ternary metal sulfide-based electrodes. Asymmetric supercapacitor device fabricated using FeCo 2 S 4 HNNA/CNF as positive electrode also delivers a high energy density of 88.5 Wh kg−1 at a power density of 800 W kg−1, as well as a superior cycling stability of 81.2% capacity retention after 5000 cycles. Graphical abstract Image 1 Highlights • FeCo 2 S 4 hollow nanoneedles are evenly deposited on conductive carbon nanofiber film. • The hollow nanoneedle arrays present the unique lawn-like and tip-welded morphology. • Composite shows high capacitance and high energy density in asymmetric supercapacitor. [ABSTRACT FROM AUTHOR]

Engineering nanostructured architecture with a hierarchically arranged active surface is regarded as an effective strategy to develop advanced electrode materials. Herein, nanosheet-built MnCo 2 S 4 micro-disks with abundant nano-pores are synthesized and uniformly dispersed on a three-dimensional nitrogen-doped carbon matrix (3DNC). In the resultant 3DNC@MnCo 2 S 4 composite architecture, N-doped carbon network provides interconnected and shortened pathways for fast ion transmission and charge transfer, and the nanosheet-built MnCo 2 S 4 disks allow the efficient Faradaic redox process through the increased active surface. Due to the compositional and structural advantages, prepared 3DNC@MnCo 2 S 4 composite architecture delivers a superior electrochemical capacitive performance than 3DNC@MnCo 2 O 4 and other sulphospinel-based electrodes (including a high specific capacitance of 1812 F g−1 at 1A g−1, and a high rate performance of 82.9% capacitance retention at 20 A g−1). When assembled into hybrid supercapacitor device, the 3DNC@MnCo 2 S 4 //AC HSC also exhibits a high energy density of 68.8 Wh kg−1 at the power density of 800 W kg−1 and excellent cycling stability (82% capacitance retention after 5000 cycles at the current density of 10 A g−1). The facile yet efficient construction of this 3D porous electrode provides an innovative method for developing high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Amorphous/crystalline FC@MS-EG heterostructure is prepared via an EG-induced method. • The flexible electrode presents high specific capacitance and capacitance retention. • The superiority of FC@MS-EG is discussed by chemical analysis and DFT calculation. • An asymmetric device shows ultrahigh energy density (88.09 Wh kg−1@750 W kg−1). Although flexible supercapacitors have important applications, the development of high-performance flexible supercapacitors still remains a critical challenge owing to the low ion diffusion rate, poor electro-conductivity, and limited active defect sites. Herein, we report the first amorphous MoS x nanoparticles grown on crystalline FeCo-based nanoneedles (FC@MS-EG) via an ethylene glycol-induced strategy. The FC@MS-EG electrode presents an unprecedented specific capacitance of 1956 F g−1 at 1 A g−1 and over 91.1% of capacitance retention even after 6000 cycles because of the unique morphology, the rich defect sites, the high carrier concentration. The FC@MS-EG//AC asymmetric supercapacitor delivers an ultrahigh specific capacitance of 282 F g−1 at 1 A g−1 and an excellent energy density of 88.09 Wh kg−1 along with a power density of 750 W kg−1. And the self-assembled flexible all-solid-state supercapacitor device can be easily bent and twisted with negligible electrochemical properties attenuation. [ABSTRACT FROM AUTHOR]

The as-fabricated ZTO/rGO nanocomposite-based LIC delivers a maximum energy density of 204 Wh kg−1 and ultrahigh power density of 67,500 W kg−1, which is expected to be an alternative energy storage device in the future. • Uniform Roselle-Like Zn 2 Ti 3 O 8 /rGO nanocomposite has been successfully synthesized. • The Zn 2 Ti 3 O 8 /rGO-based LIC can deliver a maximum energy density of 204 Wh kg−1. • The Zn 2 Ti 3 O 8 /rGO-based LIC exhibits an ultrahigh power density of 67500 W kg−1. • The LIC device exhibits excellent cycling performance in a high voltage of 4.5 V. To satisfy the sharp increasing demands of consumer and portable electronic devices, lithium ion capacitors (LICs) are required to provide higher energy and power densities. In view of this, herein, we report a feasible and controllable method to prepare uniform Roselle-like Zn 2 Ti 3 O 8 /reduced graphene oxide (ZTO/rGO) nanocomposite for application as anode of LIC. The results indicate that a compact interface is formed between ZTO and rGO through O(ZTO) − C(rGO) bonds, which can significantly enhance electron transport kinetics. As expected, the ZTO/rGO nanocomposite displays a high reversible specific capacity of 560 mAh g−1 at 0.1 A g−1 and 300 mAh g−1 at 2.0 A g−1 with superior rate capability. More remarkably, for the first time, the ZTO/rGO nanocomposite-based LIC is designed and fabricated, which delivers a high energy density of 204 Wh kg−1 at a power density of 112.5 W kg−1, and ultrahigh power density of 67500 W kg−1 with an energy density of 54.6 Wh kg−1. Moreover, the device can retain 76% of the capacity after 1000 cycles at 1.0 A g−1. The ZTO/rGO-based LIC is expected to be an alternative energy storage device in the future. [ABSTRACT FROM AUTHOR]

NiS/MoS 2 composite nanosheets were designed and prepared via facile ion-exchange, freeze-drying, and Ostwald ripening processes. MoS 2 nanosheets served as backbones to absorb Ni2+ ions and form NiS nanosheets. The electrode based on the NiS/MoS 2 composite nanosheets exhibited an ultrahigh specific capacity of 343.5 mA h g−1 at 9 A g−1, which was superior to that of as-prepared MoS 2 nanosheets (125.8 mA h g−1) and Ni(OH) 2 nanosheets (148.9 mA h g−1). In addition, NiS/MoS 2 composite nanosheets presented an enhanced rate performance and good life cycle due to their hierarchical structure, high surface area with numerous active sites, and synergistic performance. A NiS/MoS 2 //AC asymmetric supercapacitor device operated in a large potential window (0–1.5 V) delivered a high capacitance of 48.4 F g−1 at 0.1 A g−1, an excellent energy density of 15.1 Wh kg−1 and a very high power density of 2.25 kW kg−1. This smart in situ construction process opens a new route to synthesize binary metal sulfides for high-performance energy storage devices. • NiS/MoS 2 nanosheets were prepared via an ion-exchange process and Ostwald ripening. • The composite exhibits an ultra-high specific capacity and cycle lifespan. • The results were ascribed to the high surface area and low contact resistance. • A NiS/MoS 2 //AC ASC device shows excellent energy densities. [ABSTRACT FROM AUTHOR]