CAJ | 학술논문

利用间歇式高温高压水热设备在超临界和亚临界条件下合成纯度高、结晶度好的亚微米级LiFePO4颗粒，通过XRD、SEM、充放电测试对LiFePO4的结构、形貌和电化学性能进行表征，并考查反应温度、压力和3种模板剂对制备的LiFePO4材料的结构、形貌及电化学性能的影响。结果表明温度和压力的升高有利于合成较小粒径、均一分布的颗粒，以PVP作为模板剂得到的样品性能最佳，制备的LiFePO4颗粒粒径为200～600 nm，0.1 C和1 C倍率下的首次放电比容量分别为141.2 mAh/g和113.6 mAh/g，1C倍率下循环100次，其容量保持率为96.0%，制备的材料具有优异的倍率性能。
이용간헐식고온고압수열설비재초림계화아림계조건하합성순도고、결정도호적아미미급LiFePO4과립，통과XRD、SEM、충방전측시대LiFePO4적결구、형모화전화학성능진행표정，병고사반응온도、압력화3충모판제대제비적LiFePO4재료적결구、형모급전화학성능적영향。결과표명온도화압력적승고유리우합성교소립경、균일분포적과립，이PVP작위모판제득도적양품성능최가，제비적LiFePO4과립립경위200～600 nm，0.1 C화1 C배솔하적수차방전비용량분별위141.2 mAh/g화113.6 mAh/g，1C배솔하순배100차，기용량보지솔위96.0%，제비적재료구유우이적배솔성능。
The sub-micro LiFePO4 particles with high purity and crystallinity were prepared under the subcritical to supercritical water conditions during a batch high temperature and pressure hydrothermal synthesis process. The structure, morphology and electrochemical performance of LiFePO4 were characterized by X-ray diffraction, scanning electron microscope and charge-discharge test, respectively. The effects of temperature, pressure and three templates on the structure, morphology and electrochemical performance of LiFePO4 were investigated. The results show that the small and uniform particles are easy to be synthesized with the increase of temperature and pressure. The sample prepared with polyvinyl pyrrolidone (PVP) as template shows the best performance:the particle diameter of LiFePO4 is 200~600nm. The initial discharge specific capacity is 141.2 mAh/g and 113.6 mAh/g at 0.1 C and 1 C, respectively. The capacity of LiFePO4 particles is retained 96.0%at 1 C rate after 100 charge-discharge cycles, which shows the sub-micro LiFePO4 particles exhibit the excellent cycle and rate capability.