Search

Carbon nanotubes (CNTs), with their extraordinary combination of mechanical, electrical, and thermal properties, have emerged as a revolutionary class of nanomaterials with immense potential in energy storage and harvesting devices. Realizing this potential hinges on a fundamental challenge: the dispersion stability of CNTs within various matrices. This review paper provides a comprehensive exploration of the critical interplay between CNT dispersion stability and its far-reaching implications for the performance of energy storage and harvesting technologies. By delving into the underlying mechanisms of dispersion, the strategies to achieve stability, and the direct effects on device functionality, this review sheds light on the intricate relationship between nanotube dispersion and the advancement of energy-related applications. [ABSTRACT FROM AUTHOR]

Abstract: Recently developed textile and paper based supercapacitors are well-suited for wearable energy storage devices due to their mechanical flexibility and stretchability. In this study, the effects of mechanical straining on carbon nanotube coated textiles are studied, and we demonstrate the pre-straining of the textile can result in an enhanced specific capacitance as well as power and energy densities. In-situ resistance measurement during mechanical straining of the textile capacitors show a decrease in resistance with tensile straining, which contributed directly to the enhancement of electrochemical performance. Two different carbon nanotube textiles based on polyester and cotton with different mechanical behaviors are examined, where the polyester textile show an increase in specific capacitance from 53.6 F g−1 to 85.7 F g−1 after the textile is pre-strained to 30% permanent elongation prior to electrochemical testing, constituting a 37% enhancement. Similarly, the cotton textile shows an enhancement in specific capacitance from 122.1 F g−1 to 142.0 F g−1 after 30% permanent elongation, which is a 22% enhancement. Specific capacitance, energy density, and power density are increased further by electroplating of MnO2 nanoparticles on the carbon nanotube coated cotton textile and then imposing a permanent elongation of 30%. Our results indicate that the simple mechanical pre-straining of the textile fibers contribute to significant enhancements in the electrochemical performance of the supercapacitors. [Copyright &y& Elsevier]

Hydrous ruthenium oxide (RuO 2) has been considered a potential electrode for supercapacitors. However, RuO 2 is not easy to be hydrous, which impedes advancement in RuO 2 -based supercapacitors. Here, strontium cation (Sr2+) – with a lower oxidation state than Ru4+ – doping effects on improving the capability of RuO 2 to be hydrous are reported. The Sr2+ doping in the RuO 2 was simply possible using electrospinning and subsequent calcination, affecting hydrous properties and promoting miniaturization of nanograins in one-dimensional (1D) nanofibers. The compositions of hydrous Sr2+-doped RuO 2 (H-Sr x Ru 1−x O 2−x) nanofibers were optimized considering correlations between synthesis temperature and degree of hydration. It was found that the H-Sr 0.2 Ru 0.8 O 1.8 nanofibers synthesized at 400 °C were hydrous compared with the pristine RuO 2 and H-Sr 0.1 Ru 0.9 O 1.9 nanofibers. The H-Sr 0.2 Ru 0.8 O 1.8 nanofibers (400) could possess the smallest nanocrystallites, increasing electrochemically active surface area and satisfying specific capacitance of 612.6 A/g at a scan rate of 50 mV s–1. • A Sr2+-doped RuO 2 nanofibers were successfully fabricated by electrospinning and calcination. • Sr2+ doping enabled RuO 2 nanofibers to be hydrous and to possess miniaturized nanograins. • Sr2+ doping in RuO 2 was optimized for annealing temperature and composition. • The highly hydrous Sr 0.2 Ru 1.8 O 1.8 nanofibers boost the capacitance performance. [ABSTRACT FROM AUTHOR]