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Sustainable anode materials, including natural silica and biomass-derived carbon materials, are gaining increasing attention in emerging energy storage applications. In this research, we highlighted a silica/carbon (SiO2/C) derived from Streblus asper leaf wastes using a simple method. Dried Streblus asper leaves, which have plenty of biomass in Thailand, have a unique leaf texture due to their high SiO2 content. We can convert these worthless leaves into SiO2/C nanocomposites in one step, producing eco-materials with distinctive microstructures that influence electrochemical energy storage performance. Through nanostructured design, SiO2/C is thoroughly covered by a well-connected framework of conductive hybrid polymers based on the sodium alginate–polypyrrole (SA-PPy) network, exhibiting impressive morphology and performance. In addition, an excellent electrically conductive SA-PPy network binds to the SiO2/C particle surface through crosslinker bonding, creating a flexible porous space that effectively facilitates the SiO2 large volume expansion. At a current density of 0.3 C, this synthesized SA-PPy@Nano-SiO2/C anode provides a high specific capacity of 756 mAh g−1 over 350 cycles, accounting for 99.7% of the theoretical specific capacity. At the high current of 1 C (758 mA g−1), a superior sustained cycle life of over 500 cycles was evidenced, with over 93% capacity retention. The research also highlighted the potential for this approach to be scaled up for commercial production, which could have a significant impact on the sustainability of the lithium-ion battery industry. Overall, the development of green nanocomposites along with polymers having a distinctive structure is an exciting area of research that has the potential to address some of the key challenges associated with lithium-ion batteries, such as capacity degradation and safety concerns, while also promoting sustainability and reducing environmental impact. [ABSTRACT FROM AUTHOR]

In this work, water hyacinth stem waste was used as a cost-effective and sustainable precursor to synthesize carbon/iron oxide (C/FeOx) nanocomposite anode materials, which were simultaneously produced in one step of catalytic graphitization. The synthesis process was superior in terms of simplicity, scalability, simplicity of required conditions, and environmental friendliness. Intensive physical characterization revealed that the synthesized materials consisted of FeOx nanoparticles and salt contents scattered across the surface of partially graphitized carbon. This was greatly advantageous since carbon would be able to suppress the volume change effect of FeOx. As a result, electrochemical studies discovered that the C/FeOx nanocomposite with the best performance delivered a high reversible capacity of 268.5 mAh g−1 after 300 cycles at 0.1 A g−1 and 171.1 mAh g−1 after 1000 cycles at 2 A g−1. Even after cycling through 5000 cycles at a fast charge stage of 10 A g−1, this material could still function as a great anode. Also, the coulombic efficiency was found to be greater than 90% even after a long-term cycle, which demonstrated outstanding cyclic reversibility and stability achieved without any conductive additives as compared to commercial graphite. Thus, this study sheds light on the adaptive production of nanocomposite anodes from diverse biomass waste, which can be repurposed in the future to develop important sustainable energy storage applications. Also, the results indicate that these C/FeOx nanocomposite materials could be employed as low-cost anode materials in environmentally friendly lithium-ion batteries, even at fast charge–discharge rates. [ABSTRACT FROM AUTHOR]

ZnO:Al nanostructures with 1% by mole of Al were prepared by radio frequency sputtering on copper and quartz substrates. The ZnO:Al nanostructures obtained exhibited needle- or tree-like structures with the diameter ranging from 30 to 100 nm. It was suggested that these ZnO:Al nanostructures could be single-crystalline hexagonal structures growing along the direction with branching along the 〈0001〉 direction. From Hall measurement, ZnO:Al nanostructures had a resistivity in the order of 10−2Ω·cm, a carrier concentration of 1020 cm−3, and a Hall mobility of 3 cm2·(V·s)−1. From X-ray diffraction, transmission electron microscopy and Raman results, ZnO:Al nanostructures had direction perpendicular to the surface, whereas ZnO nanobelts had the c-axis perpendicular to the surface. In addition, the growth mechanism of the wire and belt-like nanostructure could be explained by kinetics of anisotropic growth via a vapor–solid mechanism. This information would be useful for further applications of ZnO:Al nanostructures. [ABSTRACT FROM AUTHOR]

By combining rice husk-derived nano-silica and reduced graphene oxide and then polymerizing PANI by in situ polymerization, we created polyaniline-coated rice husk-derived nano-silica@reduced graphene oxide (PANI-SiO 2 @rGO) composites with excellent electrochemical performance. ATR-FTIR and XRD analyses confirm the formation of PANI-SiO 2 @rGO, implying that SiO 2 @rGO served as a template in the formation of composites. The morphology of PANI-SiO 2 @rGO was characterized by SEM, HRTEM, and STEM, in which SiO 2 nanoparticles were homogeneously loaded on graphene sheets and the PANI fibrous network uniformly covers the SiO 2 @rGO composites. The structure can withstand the large volume change as well as retain electronic conductivity during Li-ion insertion/extraction. Over 400 cycles, the assembled composite retains a high reversible specific capacity of 680 mA h g -1 at a current density of 0.4 A g -1 , whereas the SiO 2 @rGO retains only 414 mA h g -1 at 0.4 A g -1 after 215 cycles. The enhanced electrochemical performance of PANI-SiO 2 @rGO was a result of the dual protection provided by the PANI flexible layer and graphene sheets. PANI-SiO 2 @rGO composites may pave the way for the development of advanced anode materials for high-performance lithium-ion batteries., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Emerging technologies demand a new generation of lithium-ion batteries that are high in power density, fast-charging, safe to use, and have long cycle lives. This work reports charging rates and specific capacities of TiO 2 (B)/N-doped graphene (TNG) composites. The TNG composites were prepared by the hydrothermal method in various reaction times (3, 6, 9, 12, and 24 h), while the N-doped graphene was synthesized using the modified Hummer's method followed by a heat-treatment process. The different morphologies of TiO 2 dispersed on the N-doped graphene sheet were confirmed as anatase-nanoparticles (3, 6 h), TiO 2 (B)-nanotubes (9 h), and TiO 2 (B)-nanorods (12, 24 h) by XRD, TEM, and EELS. In electrochemical studies, the best battery performance was obtained with the nanorods TiO 2 (B)/N-doped graphene (TNG-24h) electrode, with a relatively high specific capacity of 500 mA h g -1 at 1C (539.5 mA g -1 ). In long-term cycling, excellent stability was observed. The capacity retention of 150 mA h g -1 was observed after 7000 cycles, at an ultrahigh current of 50C (27.0 A g -1 ). The synthesized composites have the potential for fast-charging and have high stability, showing potential as an anode material in advanced power batteries for next-generation applications., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)