Hydrothermal synthesis of LiFePO₄ micro-particles for fabrication of cathode materials based on LiFePO₄/carbon nanotubes nanocomposites for Li-ion batteries

Lithium iron phosphate (LiFePO₄) micro-particles (MPs) were synthesized under hydrothermal condition for fabrication of cathode materials based on LiFePO₄ MPs/multi-walled carbon nanotube (MWCNT) nanocomposites. Influence of reaction time for the hydrothermal process on structural, morphological, and electrochemical behavior was investigated. Crystal quality was confirmed by X-ray diffraction (XRD) together with Raman analysis. Micrometer-scale seeds and capsule-shaped morphology were observed. Such nanocomposite cathodes based on LiFePO₄ MPs/MWCNT were prepared by surface-engineered tape casting technique. The well-crystallized material composed of densely aggregated MPs and interconnected with MWCNTs led to excellent volumetric Li storage properties at a current rate of 0.1 mVs⁻¹ between 2.5 to 4.3 V. However, the half-cell analysis does not show reasonable capacity values, which may be due to the larger particle size and morphology of synthesized LiFePO₄, resulting in limiting ionic transportation and electronic conduction path.