Natural Rubber-TiO₂ Nanocomposite Film for Triboelectric Nanogenerator Application

In this research, natural rubber (NR)-TiO(2) nanocomposites were developed for triboelectric nanogenerator (TENG) application to harvest mechanical energy into electrical energy. Rutile TiO(2) nanoparticles were used as fillers in NR material to improve dielectric properties so as to enhance the energy conversion performance of the NR composite TENG. The effect of filler concentration on TENG performance of the NR-TiO(2) composites was investigated. In addition, ball-milling method was employed to reduce the agglomeration of TiO(2) nanoparticles in order to improve their dispersion in the NR film. It was found that the TENG performance was significantly enhanced due to the increased dielectric constant of the NR-TiO(2) composite films fabricated from the ball-milled TiO(2). The TENG, fabricated from the NR-TiO(2) composite using 24 h ball-milled TiO(2) at 0.5%wt, delivered the highest power density of 237 mW/m(2), which was almost four times higher than that of pristine NR TENG. Furthermore, the applications of the fabricated NR-TiO(2) TENG as a power source to operate portable electronics devices were also demonstrated

A DFT study on the fundamental mechanisms of quantum capacitance enhancement within the carbon-based electrodes through different classes of doped configurations from biomass-derived elements

Density functional calculations were performed on 15 functionalized graphene models to investigate the enhancement of quantum capacitance (CQ) by common dopant elements N, P, S, and O from biomaterials. Geometry optimizations and formation energy calculations demonstrated that the van der Waals radius and additional covalent bonds influenced the mechanical stress and formation energy, particularly due to the distortion of the graphene lattice caused by larger S or P atoms replacing carbon atoms. According to both the CQ and formation energy calculations, nitrogen emerged as the most promising doping element for enhancing CQ, followed by phosphorus, while sulfur showed a relatively lower contribution. Electron density profiles indicated that the improvement of CQ was facilitated by the lone pair electrons at the defects. The effects of dopants on electronic structures were further elucidated through CQ characteristics, resulting in the classification of functionalized graphene models into three types. The ‘graphitic’ type represented configurations that preserved most of the electronic structure of pristine graphene, while ‘p-type’ and ‘n-type’ represented those experienced the loss and gain of valence electrons, respectively. This electronic structure-based classification of doping provides valuable insights for future designs, enabling control over sintering and doping conditions in biomass-derived electrode materials for supercapacitors

Dumbbell-Shaped Octasilsesquioxanes Functionalized with Ionic Liquids as Hybrid Electrolytes for Lithium Metal Batteries

Exploring solid-state electrolytes as alternatives for flammable liquid carbonate electrolyte is considered as one of the key routes toward next-generation lithium polymer batteries assembled with a high-capacity electrode. In this work, we synthesized an organic–inorganic hybrid solid electrolyte with ionic liquid moieties tethered onto dumbbell-shaped octasilsesquioxanes through oligo­(ethylene glycol) spacers. The hybrid electrolyte is featured by its high room-temperature ionic conductivity (1.2 × 10^–4 S/cm at 20 °C with LiTFSI salt), excellent electrochemical stability (4.6 V vs Li⁺/Li), and great thermal stability. Excellent capability of the hybrid electrolyte to mediate electrochemical deposition and dissolution of lithium has been demonstrated in the symmetrical lithium cells. No short circuit has been observed after more than 500 h in the polarization tests. Decent charge/discharge performance has been obtained in the prepared electrolyte based all-solid-state lithium battery cells at ambient temperature

Ag Nanoparticle-Incorporated Natural Rubber for Mechanical Energy Harvesting Application

The energy conversion performance of the triboelectric nanogenerator (TENG) is a function of triboelectric charges which depend on the intrinsic properties of materials to hold charges or the dielectric properties of triboelectric materials. In this work, Ag nanoparticles were synthesized and used to incorporate into natural rubber (NR) in order to enhance the dielectric constant for enhancing the electrical output of TENG. It was found that the size of Ag nanoparticles was reduced with the increasing CTAB concentration. Furthermore, the CTAB surfactant helped the dispersion of metallic Ag nanoparticles in the NR-insulating matrix, which promoted interfacial polarization that affected the dielectric properties of the NR composite. Ag nanoparticle-incorporated NR films exhibited an improved dielectric constant of up to almost 40% and an enhanced TENG performance that generated the highest power density of 262.4 mW/m2