By combining rice husk-derived nano-silica and reduced graphene oxide and then polymerizing PANI byin situpolymerization, we created polyaniline-coated rice husk-derived nano-silica@reduced graphene oxide composites with excellent electrochemical performance.

The development of lithium-ion batteries (LIBs) has become an important aspect of advanced technologies. Although LIBS have already outperformed other secondary batteries, they still require improvement in various aspects. Most crucially, graphite, the commercial anode, has a lower capacity than emerging materials. The goal of this research is to develop carbon-based materials from sustainable sources. Banana stem waste was employed as a precursor because of its xylem structure and large surface area. In addition, catalytic graphitization of biomass yields both graphitic carbon and metal oxides, which can be converted into higher-capacity Fe₃O₄/C nanocomposites. The nanocomposites consist of nanoparticles distributed on the surface of the carbon sheet. It was found that Fe₃O₄/C nanocomposites not only achieved a superior specific capacity (405.6 mAh/g at 0.1 A/g), but also had good stability in long-term cycling (1000 cycles). Interestingly, they had a significantly greater capacity than graphite at a high current density (2 A/g), 172.8 mAh/g compared to 63.9 mAh/g. For these reasons, the simple preparation approach, with its environmental friendliness and low cost, can be employed to produce Fe₃O₄/C nanocomposites with good electrochemical properties. Thus, this approach may be applicable to varied biomasses. These newly developed Fe₃O₄/C nanocomposites derived from banana waste recycling were found to be suitable to be used as anodes for sustainable LIBs.

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.