The abundance of raw materials is a significant advantage that positions sodium-ion batteries (SIBs) as a promising energy storage solution for the future. However, the low cycle efficiency and poor rate capacity of cathode materials have hindered the commercialization of SIBs, prompting extensive research efforts to address these challenges. Ion doping into the material structure is considered to be an effective, simple, and scalable approach to enhancing the electrical performance of cathode materials.
View Article and Find Full Text PDFEnhancement of the ionic conductivity and reduction of diffusion barriers of lithium-ion batteries are crucial for improving the performance of the fast-growing energy storage devices. Recently, the fast-charging capability of commercial-like lithium-ion anodes with the smallest modification of the current manufacturing technology has been of great interest. We used first principles methods computations with density functional theory and the climbing image-nudged elastic band method to evaluate the impact of an external electric field on the stability, electronic band gap, ionic conductivity, and lithium-ion diffusion coefficient of penta-graphene nanoribbons upon lithium adsorption.
View Article and Find Full Text PDFGraphene quantum dots have been widely studied owing to their unique optical, electrical, and optoelectrical properties for various applications in solar devices. Here, we investigate the optoelectronic properties of hexagonal and nitrogen-doped graphene quantum dots using the first-principles method. We find that doping nitrogen atoms to hexagonal graphene quantum dots results in a significant red shift toward the visible light range as compared to that of the pristine graphene quantum dots, and the doped nitrogen atoms also induce a clear signature of anisotropy of the frontier orbitals induced by the electron correlation between the doped nitrogen atoms and their adjacent carbon atoms.
View Article and Find Full Text PDFLithium-ion batteries lay the foundation for satisfying the fast-growing demand of portable electronics and electric vehicles. However, due to the complexity of material syntheses, high fabrication temperature condition, and toxic gas emission, high volume manufacturing of lithium-ion batteries is still challenging. Here, we propose a modified coprecipitation method to synthesize LiNiMnCoO (NMC622-MCP) as a cathode material in a simple, cost-effective, and environmentally friendly approach.
View Article and Find Full Text PDFWastewater containing an azo dye Orange G (OG) causes massive environmental pollution, thus it is critical to develop a highly effective, environmental-friendly, and reusable catalyst in peroxymonosulfate (PMS) activation for OG degradation. In this work, we successfully applied a magnetic MnFeO/α-MnO hybrid fabricated by a simple hydrothermal method for OG removal in water. The characteristics of the hybrid were investigated by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller method, vibrating sample magnetometry, electron paramagnetic resonance, thermogravimetric analysis, and X-ray photoelectron spectroscopy.
View Article and Find Full Text PDFWe report the synthesis of manganese-doped nickel cobalt oxide (Mn-doped NiCo2O4) nanoparticles (NPs) by an efficient hydrothermal and subsequent calcination route. The material exhibits a homogeneous distribution of the Mn dopant and a battery-type behavior when tested as a supercapacitor electrode material. Mn-doped NiCo2O4 NPs show an excellent specific capacity of 417 C g-1 at a scan rate of 10 mV s-1 and 204.
View Article and Find Full Text PDFIn this work, a feasible one-pot approach to synthesize manganese oxide/graphene composites, the so-called plasma-enhanced electrochemical exfoliation process (PEP), has been developed. Herein, a composite of graphene decorated with manganese oxide nanoparticles was prepared via PEP from a KMnO solution and graphite electrode under a voltage of 70 V in an ambient environment. By controlling the initial KMnO concentration, we obtained distinct MnO/graphene samples.
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