Dmso-Assisted Liquid-Phase Synthesis Of Lifepo₄/C Nanocomposites

with the step of electric bicycle and new energy vehicles industry getting faster and faster, energy storage technology becomes more and more important and it takes our attention gradually, and the requirements and attention for lithium ion battery of green energy industry has reached an all-time high. Lithium ion battery has already become the most promising motive power. The cathode materials play important role to the properties of lithium ion batteries. LiFePO₄ is regarded as a promising cathode material for lithium ion batteries due to its high theoretical capability (170mAh/g), stable discharge platform (3.4V), relatively low cost, excellent heat stability, low toxicity, reasonable safety, and good structural stability.In this paper the basic features and working principle of LiFePO₄ at the present time are reviewed. through discussing the problems in preparation of LiFePO₄, our research group proposed a solution-phase method to obtain LiFePO₄ nanoparticles, using dimethyl sulfoxide (DMSO) as a boiling point raiser and crystal growth inhibitor at 108°C and ambient pressure for a short time; then we mix the as-prepared LiFePO₄ powder with a certain amount of glucose, obtaining LiFePO₄/C nanocomposites with uniform particle size after sintering at 600oC under a 5% H2–95% N2 atmosphere for a short time. The obtained LiFePO₄/C nanocomposites deliver a good high-rate discharge property and excellent cycling performance. The crystalline structure, particle sizes, morphology and electrochemical performances of the composites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), Transmission electron microscopy (SEM), Infrared spectrum (IR) and electrochemical performances respectively. By analyzing the ratio of solvent to water, reactant concentration, reaction time, sintering time, and temperature we determined the optimal conditions for synthesizing LiFePO₄/C nanocomposites. And contrast and analysis the LiFePO₄ obtained directly in liquid-phase and LiFePO₄/C obtained in the optimal conditions, the rustles indicated that a certain amount of carbon-encapsulated and short time heat treatment are very important for the improvement of electrochemical performance.