Synthesis of Metal Oxide/Carbon Nanofibers via Biostructure Confinement as High-Capacity Anode Materials

Abstract

For applications in energy storage and conversion, many metal oxide (MO)/C composite fibers have been synthesized using cellulose as the template. However, MO particles in carbon fibers usually experience anomalous growth to a size of >200 nm, which is detrimental to the overall performance of the composite. In this paper, we report the successful development of a generic approach to synthesize a fiber composite with highly dispersed MO nanoparticles (10–80 nm) via simple swelling, nitrogen doping, and carbonization of the cellulose microfibril. The growth of the MO nanoparticles is confined by the structure of the microfibrils. Density functional theory calculation further reveals that the doped N atoms supply ample nucleation sites for size confinement of the nanoparticles. The encapsulation structure of small MO nanoparticles in the conductive carbon matrix improves their electrochemical performance. For example, the formed SnO x /carbon nanocomposite exhibits high specific capacities of 1011.0 mA h g–1 at 0.5 A g–1 and 581.8 mA h g–1 at 5 A g–1. Moreover, the fiber-like nanocomposite can be combined with carbon nanotubes to form a flexible binder-free electrode with a capacity of ∼10 mA h cm–2, far beyond the commercial level. The process developed in this study offers an alternative approach to sophisticated electrospinning for the synthesis of other fiber-like MO/carbon nanocomposites for versatile applications.

Preparation and characterization study of γ-Fe2O3/carbon composite nanofibers: electrospinning of composite fibers using PVP and iron nitrate as precursors

“…In recent years, metal oxide-carbon (MO-C) materials, due to their intriguing physical, chemical, electrical, and optical properties as well as their ability to combine multiple advantages and performance characteristics, have become one of the most important research topics. 1,2 Carbon materials with a large specific surface area and easy access to various pore sizes have attracted intense research, [3][4][5][6][7][8][9][10][11] although some deficiencies such as their low dispersibility in water make them undesirable for some applications. Metal oxide materials, also in spite of their versatile properties, possess some weak properties, such as low electrical conductivities, which restricts them in many applications.…”

Inside the failure mechanism of tin oxide as anode for sodium ion batteries

“…To solve these problems, some strategies have been proposed, such as the morphology control to reduce the Na diffusion paths between electrolyte and electrode, the production of heterostructures with other semiconducting materials and the hybridization with conductive additives for reduction of volume changes and improvement of conductivity. Composites with rGO, graphene, MWCNTs or porous carbon nanofibers or with doped carbon sources, heterostructures with sulfide (SnS 2 or MoS 2 ) were prepared as well as the use of oxygen vacancies engineering has been reported [10][11][12][13][14][15]. However, in the literature, not many efforts have been devoted to pure SnO 2 , to tailoring its particle dimensions to improve its cycling performances.…”