High-performance carbon-coated LiMnPO4 nanocomposites by facile two-step solid-state synthesis for lithium-ion battery

摘要

LiMnPO4/C powders have been prepared by a solid-state method with sucrose as carbon source. The structure, morphology, and electrochemical performance of the LiMnPO4/C samples have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electronic microscopy (TEM), galvanostatic charge and discharge, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The LiMnPO4/C sample prepared by the two-step solid-state method exhibits a specific capacity of 156 mA h g(-1) after 40 cycles, and over 90 % of the initial capacity can be retained with a charge-discharge rate of 0.5 C and a voltage range of 2.5-4.4 V at 50 A degrees C. The improvement of electrochemical performance attributes to the highly uniform distribution of the minimizing particle size as well as the superior electrical conductivity of the carbon-coated nano-LiMnPO4 materials by facile two-step solid-state synthesis.