论文部分内容阅读
采用高温固相法合成了Li_(1.05)Fe_(0.97)Nb_(0.03)PO_4/C,考察了二次煅烧温度对材料结构和电化学性能的影响。采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对材料的结构和形貌进行表征。结果表明:700℃合成的Li_(1.05)Fe_(0.97)Nb_(0.03)PO_4/C正极材料晶体结构以及形貌没有发生改变,仍为橄榄石型结构且具有最佳电化学性能。在0.1C倍率,2.4~4.2V电压范围下首次放电比容量为161.2mAh/g;经过100次循环后,容量保持率为95.16%,具有良好的倍率性能和循环性能。
Li 1.05 Fe 0.97 Nb 0.03 PO 4 / C was synthesized by solid-state reaction at high temperature. The effect of secondary calcination temperature on the structure and electrochemical properties of the material was investigated. The structure and morphology of the material were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the crystal structure and the morphology of Li 1.05 Fe 0.97 Nb 0.03 P 4 / C cathode material synthesized at 700 ℃ have no change and are still olivine structure with the best electrochemical performance. The specific discharge capacity at initial discharge rate of 161.2mAh / g at 0.1C rate and 2.4 ~ 4.2V voltage range was 95.16% after 100 cycles, with good rate performance and cycle performance.