Effect of silver and carbon double coating on the electrochemical performance of LiFePO4 cathode material for lithium ion batteries


Goktepe H., Sahan H., PATAT Ş.

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, cilt.41, sa.23, ss.9774-9779, 2016 (SCI-Expanded) identifier identifier

Özet

Olivine-type LiFePO4 composite materials for use as the cathode material in lithium-ion batteries were synthesized by using a hydrothermal method and then they were coated with silver and carbon. The phase identification and morphological characterization of four different LFP composites were performed,by X-ray diffraction (XRD) and scanning electron microscopy (SEM) along with energy dispersive spectroscopy which verified the homogeneous existence of coated silver. The electrochemical performance was studied by conductivity measurements and galvanostatic charge-discharge measurements. The coated LFP sample exhibited an enhanced electronic conductivity of 1.3*10(-3) Scm(-1) which is six magnitudes higher than that of pure LFP. The results revealed that the first discharge capacity of the LFP@C@Ag electrode was 152 mAhg(-1), which is higher than that of the pristine uncoated LFP electrode (122 mAhg(-1)). The improved capacity of LFP@C@Ag may be attributed to increased electrode conductivity and to the synergistic effect of the double coating on electron and Li+ transport. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.