| With the advent of energy crisis, energy structure in the world change from fossil fuels to renewable energy sources such as wind power and solar energy conversion. The precondition of this transformation is to search a suitable energy storage system to meet the needs of different types of renewable energy. In addition, the development of hybrid and electric cars is also inseparable from the efficient power storage systems. Lithium ion battery as a new energy storage and power battery, the power supply and static storage has a wide development potential.The second and third chapter of paper discusses the optimum parameters of liquid phase synthesis of LiFePO4auxiliarily using DMSO, then in the optimum parameters obtained a series of LiFePO4, then mixed with a certain amount of glucose and sintered at600℃under inert atmosphere for3h to obtain a series of LiFePO4/C nano-composites, Then XRD, SEM and electrochemical performance testing proved that the obtained LFP and LFP/C of different cycle times had no difference. Tests showed that the special capacity of LiFePO4/C at discharge rates of0.2C and2C was162.6and145.9mAh/g, respectively. A capacity of134.8mAh/g at5C and115.5mAh/g at IOC was even achievable, with no significant capacity fading after300cycles.In the fourth chapter, the LiFePO4precursor contained element of Li、Fe、P was synthesized in the Triethylene glycol (TEG)/H2O system under ambient pressure and108℃during a short time. The XRD and SEM results show that:the obtained precursor belonged to amorphous structure, and LiFePO4/C nanocomposites was obtained by sintering at600℃with a certain amount of glucose under inert atmosphere for3h. Electrochemical tests showed that the special capacity of nanometer LiFePO4/C at discharge rates of0.2was156.3mAhg-1and has the better discharge platform. A capacity of133.9mAhg-1at5C and109.9mAhg-1at10C was even achievable, with no significant capacity fading after200cycles, showing excellent rate discharge characteristics and cycle performance. |
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