磷酸铁锂材料在水溶液中嵌锂行为研究

Study on Insert Li^+ Process of LiFePO_4 in Aqueous Electrolyte

应用扫描循环伏安法研究LiFePO4材料在LiNO3水溶液体系中的脱/嵌锂过程,该扫描曲线是一个完整的、闭合的氧化/还原峰曲线,峰型尖锐,说明LiFePO4材料在水溶液体系中具有良好的电化学可逆性。对LiFePO4材料在LiNO3水溶液中进行恒电位嵌锂,对嵌锂后的LiFePO4材料进行恒电位脱锂,将嵌入材料中的Li+释放到去离子水溶液中,成为含Li+水溶液。以紫外分光光度法测定其中Li+的吸光度,对照标准Li+吸光度~浓度(g/L)曲线,对应的浓度即为溶液中Li+浓度。计算出LiFePO4材料的嵌锂效率约为35%。说明LiFePO4材料可以作为含Li+水溶液的嵌锂材料进行提锂。但是提锂效率低。

The insert/extract of the Li＋ process of LiFePO4 in aqueous solution was investigated by scan rate cyclic voltammetry.Scan curves were complete,closed curves of oxidation and reduction peaks,the peaks were sharp,and indicated that LiFePO4 had good electrochemical reversibility in aqueous solution during insertion and extraction process.Putting LiFePO4 into LiNO3 aqueous solution for potentiostatic Li＋ insertion,and LiFePO4 into demonized water for potentiostatic Li＋extraction,Li＋ aqueous became solution.Using UV spectrophotometry method to determinate the absorption of Li＋,contrasted standard absorbance to concentration（g/L） curve,corresponded concentration was the concentration of Li＋,calculated the insert Li＋ efficiency of the LiFePO4 was about 35%.The resort showed that LiFePO4 was a material to insert Li＋ in aqueous solution.However,it was inefficient.