FABRICATION OF CARBON-COATED LITHIUM IRON PHOSPHATE POUCH CELL

Abstract

This paper presents the fabrication, structural characterization, and electrochemical performance of carbon-coated lithium iron phosphate (LiFePO₄/C) cathodes assembled into pouch-type lithium-ion batteries. The LiFePO₄/C composite was synthesized via a coprecipitation process followed by in-situ carbonization to enhance electrical conductivity. X-ray diffraction (XRD) confirmed the orthorhombic olivine structure with high crystallinity, while scanning electron microscopy (SEM) showed well-dispersed nanosized particles uniformly coated with a thin carbon layer. Cyclic voltammetry measurements exhibited well-defined Fe2+/Fe3+ redox peaks at approximately 3.25 V and 3.42V  demonstrating reversible lithium insertion and extraction with minimal polarization. Galvanostatic charge-discharge tests displayed a stable voltage plateau near 3.4 V and high coulombic efficiency (~96%), reflecting excellent electrochemical reversibility. The coated electrodes retained over 90% of their initial capacity after several charge-discharge cycles, signifying enhanced cycling stability and reduced capacity fading. The results demonstrate that carbon coating effectively enhances the electrochemical stability and rate performance of LiFePO₄ cathodes, making them suitable for safe and efficient pouch cell applications.