Electrochemical performance of freestanding LiFePO₄/MWCNT composite electrodes and its ex situ studies

Lithium iron phosphate (LiFePO₄) micro-particles were synthesized using hydrothermal method with two different Fe precursors (FeSO₄ and FeCl₂). Freestanding and flexible LiFePO₄/multi-walled carbon nanotube (MWCNT) composite electrodes were prepared using surface-engineered tape-casting method. FeSO₄ precursor-based composite electrode exhibited improved electrical and electrochemical performances compared with the FeCl₂ precursor-based composite electrode. A maximum electrical conductivity of 1.54 × 10³ Scm⁻¹ has been obtained for FeSO₄ precursor-based LiFePO₄ micro-particles at 75 °C. LiFePO₄/MWCNT composite electrode exhibited better capacity (~ 126 mAhg⁻¹ at 0.1 C rate) and electrochemical reversibility in line with the results on the literature. Moreover, after 100 cycles at the rate of 1 C, specific capacity of around 105 mAhg⁻¹ and retention rate of ~ 99% were achieved. The improved performance of LiFePO₄/MWCNT composite electrode after 100 cycles leads to analyze extensive electrochemical properties and ex situ studies. [Figure not available: see fulltext.]