Synthesis Of LiFePO4 Research Articles

Synthesis of LiFePO 4 nanoparticles and their electrochemical properties

LiFePO 4 nanoparticles were synthesized via polyol process. The temperature of the solution was rapidly increased up to 320 °C to obtain larger particles and the temperature was maintained for 16 h in a round-bottomed flask attached to a refluxing condenser. The X-ray diffractrion (XRD), pattern was indexed on the basis of orthorhombic olivine structure. The LiFePO 4 compound prepared through polyol process exhibited a high crystallinity. The particles show the various shapes with size ranging from 100 to 300 nm. The initial discharge curve of LiFePO 4 capacity shows 168 mA h/g at the 0.1 C rate in the voltage range of 2.5–4 V with well-formed plateau.

Effect of Calcination Temperature on the Compositions and Electrochemical Performance of Products in the Synthesis of LiFePO<SUB>4</SUB>

Effect of Calcination Temperature on the Compositions and Electrochemical Performance of Products in the Synthesis of LiFePO<SUB>4</SUB>

Hydrothermal Synthesis of LiFePO4 under Inert Atmosphere

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Synthesis of LiFePO 4 micro and nanoparticles in supercritical water

Two synthesis routes for the production of LiFePO 4 particles were investigated in water at subcritical and supercritical conditions. Micron and nano-sized particles of LiFePO 4 were obtained via both routes, with nano-sized particles predominating when temperature was above the critical temperature of water. Our results suggest that synthesis in supercritical water is attractive for obtaining nanometer-sized crystalline particles of LiFePO 4 with a low degree of agglomeration. Electrochemical tests showed that this material exhibited improved capacity compared with LiFePO 4 prepared via other methods.

Synthesis of LiFePO[sub 4] Nanoparticles in Polyol Medium and Their Electrochemical Properties

LiFePO 4 nanoparticles were synthesized using the polyol process without any further heating as a postprocessing step. The X-ray diffraction patterns of the sample exhibited a good fit with the orthorhombic phase with no unwanted impurity phases. The LiFePO 4 nanoparticles showed a reversible capacity of 166 mAh/g, which amounts to a utilization efficiency of 98%, with an excellent reversibility in extended cycles. The electrode shows an excellent capacity retention at high-rate current densities due to its single-crystal-like and monodispersed uniform morphology with orthorhombic shape with an average width of 20 nm and length of 50 nm.

Novel synthesis of LiFePO 4 by aqueous precipitation and carbothermal reduction

LiFePO 4 is prepared by aqueous precipitation of FePO 4·2H 2O from FeSO 4·7H 2O and NH 4H 2PO 4 with hydrogen peroxide as the oxidizing agent, following carbothermal reduction with carbon as the reducer. Samples were characterized by XRD and SEM. It was showed that pure and homogenous LiFePO 4 was successfully obtained below 600 °C. The size of the material synthesized at 560 °C for12 h is about 0.1–0.3 μm. Residual carbon during processing was coated on LiFePO 4, resulting in the enhancement of the material's electronic properties. Electrochemical measurements show that the material synthesized at 560 °C for 12 h has a best electrochemical performance and its discharge capacity is about 152 mAh g −1 at 0.1 C rate and 129 mAh g −1 at 1 C rate with satisfactory capacity retention.

Synthesis of LiFePO4 by one-step annealing under the vacuum condition

Synthesis of LiFePO4 by one-step annealing under the vacuum condition

Synthesis of LiFePO 4 with fine particle by co-precipitation method

LiFePO 4 is a potential candidate for the cathode material of the lithium secondary batteries. A co-precipitation method was adopted to prepare LiFePO 4 because it is simple and cheap. Nitrogen gas was needed to prevent oxidation of Fe 2+ in the aqueous solution. The co-precipitated precursor shows the high reactivity with the reductive gas, and the single phase of LiFePO 4 is successfully synthesized with the aid of carbon under less reductive conditions. LiFePO 4 fine powder prepared by co-precipitation method shows high rate capability, impressive specific capacity and cycle property.

Synthesis of LiFePO 4 by co-precipitation and microwave heating

LiFePO 4 is a potential candidate for the cathode material of the lithium secondary batteries. Co-precipitation method and microwave heating were adopted to study about LiFePO 4. The samples were characterized by X-ray diffraction, scanning electron microscope, particle-size analysis, ICP composition analysis and electrochemical methods. Olivine phase LiFePO 4 was successfully synthesized in a few minutes. The specific capacity, cycle property and rate capability were impressive as compared with previous reports. The microwave heating method using activated carbon is a very simple and useful tool to control the iron oxidation state to 2+ without reductive gas flow.

Synthesis of LiFePO 4 cathode material by microwave processing

We report on a novel synthetic method of microwave processing with a domestic microwave oven to prepare LiFePO 4 cathode materials. We also studied and report on the electrochemical properties of the resultant products. XRD revealed that a single phase LiFePO 4 powder can be synthesized quickly and easily by microwave processing. The initial discharge capacity of a cell assembled with the powder was 125 mAh/g at 60 °C. The LiFePO 4 obtained has a high electrochemical capacity and good cycle ability. These results indicate that microwave processing is a promising method for preparing LiFePO 4 cathode materials.

Synthesis of LiFePO4 for Rechargeable Lithium Battery by Hydrothermal Reaction using High Purity FeSO4

Synthesis of LiFePO4 for Rechargeable Lithium Battery by Hydrothermal Reaction using High Purity FeSO4