由PAM合成磷酸亚铁锂/碳及其充放电性能研究

Synthesis of LiFePO_4/C from PAM and Its Electrochemical Performance

以聚丙烯酰胺(PAM)为碳源,用固相法于不同温度下合成磷酸亚铁锂/碳,并组装成模拟电池测试电化学性能.在0.1mA/cm2的电流密度下,625℃合成的样品第10个循环的放电容量达到110mAh/g,80个循环后仍能保持初始放电容量.发现在实验的温度区间内,磷酸亚铁锂晶粒度值的对数与反应温度值的负倒数成正比;另外,随反应温度的升高,FT-IR谱中1090、1055cm-1位置附近的两个峰呈分裂趋势.样品的颗粒大小不均一,这与球磨法的特点有关.初步认为样品中的颗粒是多晶结构.

LiFePO4/C was synthesized at different temperatures using polyacrylamide (PAM) as the carbon source. The electrochemical performance was tested using analogous cells. The sample synthesized at 625℃ could deliver 110 mAh/g in the 10th cycle under the current density of 01 mA/cm2, and it kept the primary discharge capacity after 80 cycles. It was first reported that lnG was direct proportional to 1/T from 550℃ to 700℃, and higher synthesizing temperature led to the split of FTIR adsorption peaks located near 1090 and 1055 cm-1 that were both attributed to υ3 vibration. The particle sizes of the sample synthesized at 625℃ were not uniform, and this was due to the characteristic of ball milling method. It suggested that the particles were polycrystals from the SEM photo.