Realizing High-Performance Lithium Storage by Fabricating FeTiO3 Nanoparticle-Impregnated Multichannel Carbon Nanofibers with Promoted Reaction Kinetics.

Abstract

In this paper, a free-standing film of ilmenite FeTiO3 nanoparticle-impregnated porous multichannel N-doped carbon nanofibers (NF-FTO) is fabricated via electrospinning technology. The as-prepared NF-FTO film is highly flexible and can be tailored to a suitable size to assemble into lithium-ion batteries. The introduction of a conductive N-doped carbon matrix is conducive to the improvement of intrinsic electronic conductivity and the acceleration of Li+ diffusion kinetics. The construction of the porous structure and highly parallel channels facilitates the transfer of electrolyte to FTO particles through the pores and shortens the transport path of lithium ions. Thus, the self-supporting electrode yields an initial charge capacity of 718.5 mAh g-1 at 50 mA g-1, a high-rate performance of 410.4 mAh g-1 at 3 A g-1, and an outstanding cycling performance with no capacity decay after 1500 cycles at 3 A g-1. By ex situ X-ray diffraction and transmission electron microscopy analysis, the reaction mechanism of NF-FTO is determined as a reversible conversion reaction. Furthermore, the assembled LiFePO4/NF-FTO full cell delivers an initial discharge capacity of 521 mAh g-1 and superb rate performance.