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In this study, we demonstrate rapid and facile supersonic cold spray deposition of Zn2SnO4 /SnO2/CNT nanocomposite supercapacitor electrodes with promising combinations of power and energy density. Cyclic voltammetry confirmed the capacitive behavior of the optimized electrode, with specific capacitance reaching 260 F·g–1 at a current density of 10 A·g–1. We attribute this high performance to the optimal combination of CNT (carbon nanotube; double-layer capacitance) and Zn2SnO4 /SnO2 (pseudocapacitance) properties. The mesoporous and accessible surface of the CNT significantly contributed to the excellent retention (approximately 93%) of the specific capacitance after 15000 galvanostatic charge/discharge cycles. In addition, the supercapacitor exhibited a remarkable energy density, electrochemical properties, and mechanical stability. The materials and approach presented here can enable cost-effective, efficient, and scalable production of high-performance supercapacitor electrodes.

A crystalline ZnO/MnO x nanoflower (NF) nanocomposite was deposited on Ni nanocones via an economical synthesis method in which the ZnO NFs were first synthesized, and MnO x was then deposited on the ZnO petals to form a heterostructured composite. The effect of the MnO x coating on the performance of the nanocomposite was analyzed by comparing the performance of supercapacitors employing ZnO and the ZnO/ MnO x nanocomposites. The ZnO/MnO x nanocomposites exhibited excellent current rate capability and an excellent capacitance of 556 F•g −1 at a current density of 1 A•g −1 . The optimized ZnO/MnO x NF electrode presented a remarkable longterm cycling stability, with a capacitance retention of 96% after 10,000 cycles. In a coin cell assembly, at an operating voltage of 0.9 V, the energy density of the optimized supercapacitor cell was 16 Wh•kg, −1 at a power density of 225 W•kg −1 . Becasue of its excellent electrochemical performance, the optimized ZnO/MnO x NF composite electrode is promising for high-energy-density supercapacitor applications.

Wearable electronic textiles are used in sensors, energyharvesting devices, healthcare monitoring, human−machine interfaces, and soft robotics to acquire real-time big data for machine learning and artificial intelligence. Wearability is essential while collecting data from a human, who should be able to wear the device with sufficient comfort. In this study, reduced graphene oxide (rGO) and silver nanowires (AgNWs) were supersonically sprayed onto a fabric to ensure good adhesiveness, resulting in a washable, stretchable, and wearable fabric without affecting the performance of the designed features. This rGO/AgNW-decorated fabric can be used to monitor external stimuli such as strain and temperature. In addition, it is used as a heater and as a supercapacitor and features an antibacterial hydrophobic surface that minimizes potential infection from external airborne viruses or virus-containing droplets. Herein, the wearability, stretchability, washability, mechanical durability, temperature-sensing capability, heating ability, wettability, and antibacterial features of this metallized fabric are explored. This multifunctionality is achieved in a single fabric coated with rGO/AgNWs via supersonic spraying.

Here, ultrathin, flexible, and sustainable nanofiber‐based piezoelectric nanogenerators (NF‐PENGs) are fabricated and applied as wave energy harvesters. The NF‐PENGs are composed of poly(vinylidene fluoride‐co‐trifluoroethylene) (P(VDF‐TrFE)) nanofibers with embedded barium strontium titanate (BaSrTiO3) nanoparticles, which are fabricated by using facile, scalable, and cost‐effective fiber‐forming methods, including electrospinning and solution blowing. The inclusion of ferroelectric BaSrTiO3 nanoparticles inside the electrospun P(VDF‐TrFE) nanofibers enhances the sustainability of the NF‐PENGs and results in unique flexoelectricity‐enhanced piezoelectric nanofibers. Not only do these NF‐PENGs yield a superior performance compared to the previously reported NF‐PENGs, but they also exhibit an outstanding durability in terms of mechanical properties and cyclability. Furthermore, a new theoretical estimate of the energy harvesting efficiency from the water waves is introduced here, which can also be employed in future studies associated with various nanogenerators, including PENGs and triboelectric nanogenerators.

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