Hydrothermal Synthesis of Spindle-Like Nanostructured LiFePO4 Powders Mediated by Organic Acid

Well-crystallized spindle-like narrow size distribution (100 similar to 140 nm) LiFePO4 nanoparticles for high rate lithium-ion battery cathode is synthesized via hydrothermal route employing amino tris(methylene phosphonic acid) (ATMP) as a surfactant. The samples are characterized by powder X-ray diffraction (XRD), dynamic Light Scattering (DLS), galvanostatic charge and discharge tests, scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) measurements. Both the pure (F-blank) and with AMPT (F-AMPT) composites exhibit comparable capacities of 160.57 mAh g(-1) and 132.53 mAh g(-1) (0.1 C), 152.36 mAh g(-1) and 121.36 mAh g(-1) (0.5 C), and 126.57 mAh g(-1) and 95.57 mAh g(-1) (5 C), respectively. The capacity retention rates of F-AMPT sample over 50 cycles at 0.1 C is 95.57 % while F-blank yields 85.26 %. EIS measurements confirm that F-AMPT sample has an increased lithium ion diffusion coefficient of 1.62x10(-12) cm(2) s(-1) due to its higher surface area.