SiO2/C Composite as a High Capacity Anode Material of LiNi0.8Co0.15Al0.05O2 Battery Derived from Coal Combustion Fly Ash

Insight into the Role of Conductive Polypyrrole Coated on Rice Husk-Derived Nanosilica-Reduced Graphene Oxide as the Anodes: Electrochemical Improvement in Sustainable Lithium-Ion Batteries

Polypyrrole (PPy) is a type of conducting polymer that has garnered attention as a potential electrode material for sustainable energy storage devices. This is mostly attributed to its mechanical flexibility, ease of processing, and ecologically friendly nature. Here, a polypyrrole-coated rice husk-derived nanosilica-reduced graphene oxide nanocomposite (SiO2-rGO@PPy) as an anode material was developed by a simple composite technique followed by an in situ polymerization process. The architecture of reduced graphene oxide offers a larger electrode/electrolyte interface to promote charge-transfer reactions and provides sufficient space to buffer a large volume expansion of SiO2, maintaining the mechanical integrity of the overall electrode during the lithiation/delithiation process. Moreover, the conducting polymer coating not only improves the capacity of SiO2, but also suppresses the volume expansion and rapid capacity fading caused by serious pulverization. The present anode material shows a remarkable specific reversible capacity of 523 mAh g-1 at 100 mA g-1 current density and exhibits exceptional discharge rate capability. The cycling stability at a current density of 100 mA g-1 shows 81.6% capacity retention and high Coulombic efficiency after 250 charge-discharge cycles. The study also pointed out that this method might be able to be used on a large scale in the lithium-ion battery industry, which could have a big effect on its long-term viability. Creating sustainable nanocomposites is an exciting area of research that could help solve some of the biggest problems with lithium-ion batteries, like how easy they are to make and how big they can be used in industry. This is because they are sustainable and have less of an impact on the environment.

Recent Advances on Porous Siliceous Materials Derived from Waste

In recent years, significant efforts have been made in view of a transition from a linear to a circular economy, where the value of products, materials, resources, and waste is maintained as long as possible in the economy. The re-utilization of industrial and agricultural waste into value-added products, such as nanostructured siliceous materials, has become a challenging topic as an effective strategy in waste management and a sustainable model aimed to limit the use of landfill, conserve natural resources, and reduce the use of harmful substances. In light of these considerations, nanoporous silica has attracted attention in various applications owing to the tunable pore dimensions, high specific surface areas, tailorable structure, and facile post-functionalization. In this review, recent progress on the synthesis of siliceous materials from different types of waste is presented, analyzing the factors influencing the size and morphology of the final product, alongside different synthetic methods used to impart specific porosity. Applications in the fields of wastewater/gas treatment and catalysis are discussed, focusing on process feasibility in large-scale productions.

Emerging waste-to-wealth applications of fly ash for environmental remediation: A review

The considerable increase in world energy consumption owing to rising global population, intercontinental transportation and industrialization has posed numerous environmental concerns. Particularly, in order to meet the required electricity supply, thermal power plants for electricity generation are widely used in many countries. However, an annually excessive quantity of waste fly ash up to 1 billion tones was globally discarded from the combustion of various carbon-containing feedstocks in thermoelectricity plants. About half of the industrially generated fly ash is dumped into landfills and hence causing soil and water contamination. Nonetheless, fly ash still contains many valuable components and possesses outstanding physicochemical properties. Utilizing waste fly ash for producing value-added products has gained significant interests. Therefore, in this work, we reviewed the current implementation of fly ash-derived materials, namely, zeolite and geopolymer as efficient adsorbents for the environmental treatment of flue gas and polluted water. Additionally, the usage of fly ash as a catalyst support for the photodegradation of organic pollutants and reforming processes for the corresponding wastewater remediation and H₂ energy generation is thoroughly covered. In comparison with conventional carbon-based adsorbents, fly ash-derived geopolymer and zeolite materials reportedly exhibited greater heavy metal ions removal and reached the maximum adsorption capacity of about 150 mg g^-1. As a support for biogas reforming process, fly ash could enhance the activity of Ni catalyst with 96% and 97% of CO₂ and CH₄ conversions, respectively.

Fast-Charging Anode Materials and Novel Nanocomposite Design of Rice Husk-Derived SiO2 and Sn Nanoparticles Self-Assembled on TiO2(B) Nanorods for Lithium-Ion Storage Applications

A novel microstructure of anode materials for lithium-ion batteries with ternary components, comprising tin (Sn), rice husk-derived silica (SiO2), and bronze-titanium dioxide (TiO2(B)), has been developed. The goal of this research is to utilize the nanocomposite design of rice husk-derived SiO2 and Sn nanoparticles self-assembled on TiO2(B) nanorods, Sn-SiO2@TiO2(B), through simple chemical route methods. Following that, the microstructure and electrochemical performance of as-prepared products were investigated. The major patterns of the X-ray diffraction technique can be precisely indexed as monoclinic TiO2(B). The patterns of SiO2 and Sn were found to be low in intensity since the particles were amorphous and in the nanoscale range, respectively. Small spherical particles, Sn and SiO2, attached to TiO2(B) nanorods were discovered. Therefore, the influence mechanism of Sn-SiO2@TiO2(B) fabrication was proposed. The Sn-SiO2@TiO2(B) anode material performed exceptionally well in terms of electrochemical and battery performance. The as-prepared electrode demonstrated outstanding stability over 500 cycles, with a high discharge capacity of ∼150 mA h g-1 at a fast-charging current of 5000 mA g-1 and a low internal resistance of around 250.0 Ω. The synthesized Sn-SiO2@TiO2(B) nanocomposites have a distinct structure, the potential for fast charging, safety in use, and good stability, indicating their use as promising and effective anode materials in better power batteries for the next-generation applications.

Carbon-Coated SiO2 Composites as Promising Anode Material for Li-Ion Batteries

Porous silica-based materials are a promising alternative to graphite anodes for Li-ion batteries due to their high theoretical capacity, low discharge potential similar to pure silicon, superior cycling stability compared to silicon, abundance, and environmental friendliness. However, several challenges prevent the practical application of silica anodes, such as low coulombic efficiency and irreversible capacity losses during cycling. The main strategy to tackle the challenges of silica as an anode material has been developed to prepare carbon-coated SiO₂ composites by carbonization in argon atmosphere. A facile and eco-friendly method of preparing carbon-coated SiO₂ composites using sucrose is reported herein. The carbon-coated SiO₂ composites were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetry, transmission and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, cyclic voltammetry, and charge–discharge cycling. A C/SiO₂-0.085 M calendered electrode displays the best cycling stability, capacity of 714.3 mAh·g⁻¹, and coulombic efficiency as well as the lowest charge transfer resistance over 200 cycles without electrode degradation. The electrochemical performance improvement could be attributed to the positive effect of the carbon thin layer that can effectively diminish interfacial impedance.