Synthesis of bowl-like mesoporous LiFePO₄/C composites as cathode materials for lithium ion batteries

By Lv, Yi-Ju; Long, Yun-Fei; Su, Jing; Lv, Xiao-Yan & Wen, Yan-Xuan
Published in Electrochimica Acta NULL 2014

Abstract

Mesoporous bowl-like LiFePO₄/C composites were synthesized by a wet milling-spray drying-carbothermal reduction (WSC) using starch as the organic carbon source and reductive agent. The samples were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, cyclic voltammograms (CV), electrochemical impedance spectra (EIS) and galvanostatic charge–discharge testing. Most of the mesoporous bowl-like LiFePO₄/C composites with particle size in the range 5–10 μm, coated with evenly distributed carbon, were assembled by nanoparticles (< 100 nm), and had a mesoporous structure with the pore size of 13.30 nm and a specifc surface area of 29.40 m2 g⁻¹. These delivered a discharge capability of 123 mAh g⁻¹ at 10 C, with no capacity loss after 100 cycles. The enhanced electrochemical performance was mainly ascribed to the improved ionic/electronic conductivity and structural stability arising from the interconnected mesoporous pores, carbon-coated nanoparticles and micro-sized structure.

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