MoO42-取代对Nasicon型Li3Fe2(PO4)3正极材料电化学性能的影响 |
Effect of MoO42- Substitution on Electrochemical Properties of Nasicon Li3Fe2(PO4)3 Cathode |
作者 | 单位 | E-mail | 张勃 | 河北工业大学, 材料科学与工程学院, 天津 300130 | | 何珺 | 河北工业大学, 材料科学与工程学院, 天津 300130 | | 华正伸 | 河北工业大学, 材料科学与工程学院, 天津 300130 | | 鲁豪祺 | 河北工业大学, 材料科学与工程学院, 天津 300130 | | 王新 | 河北工业大学, 材料科学与工程学院, 天津 300130 | | 彭会芬 | 河北工业大学, 材料科学与工程学院, 天津 300130 天津市材料层状复合与界面控制技术重点实验室, 天津 300130 | peng@hebut.edu.cn |
|
摘要: 以MoO42-部分取代Li3Fe2(PO4)3中的PO43-,研究表明:加入的MoO42-离子主要以固溶形式存在于Li3Fe2(PO4)3中,起到了显著改善其电化学性能的作用。其中,MoO42-掺杂浓度为0.3的样品表现出最佳的电化学性能,其在0.5C倍率下的首次放电容量为113.7 mAh·g-1,这一数值比未掺杂的提高了20.7%;经过60次循环充放电,容量保持率为94%。将放电倍率从0.5C逐步增大至5C,再降至初始的0.5C,并在每个倍率循环10次,这一材料的最终放电容量可达首次0.5C的95%。这些优异的性能应归因于MoO42-掺杂使材料的氧化还原能力增强,氧化还原电对的电势差减小,电池内部的电荷转移电阻减小,以及Li+扩散系数增加。 |
关键词: 正极材料 锂电池 混合阴离子效应 阴离子掺杂 电化学性能 |
基金项目: 河北省自然科学基金(No.E2016202358)资助项目。 |
Abstract: MoO42- polyanion was tried to substitute for PO43- partially in the Li3Fe2(PO4)3 compound. The results proved that the introduced MoO42- anions mainly dissolved in the Li3Fe2(PO4)3 and the corresponding electrochemical properties were improved apparently. Among the MoO42- substituted materials, the sample with MoO42- content of 0.3 presented the excellent electrochemical properties. Its initial discharging capacity was 113.7 mAh·g-1 at a rate of 0.5C, which was about 20.7% higher than that without any MoO42-. The capacity retention was about 94% at a rate of 0.5C after 60 cycles. Moreover, this material could restore 95% of the initial capacity when the discharging rate was reset back to 0.5C even after higher cycling rate of 5C. The boost in electrochemical properties for the MoO42- substituted samples is ascribed to the synergistic effects of improved redox ability, decreased potential polarization and charge transfer resistance as well as increased diffusion coefficient of lithium ions. |
Keywords: cathode lithium battery mixed anion effect anion substitution electrochemical properties |
投稿时间:2016-05-19 修订日期:2016-09-19 |
摘要点击次数: 1170 |
全文下载次数: 1632 |
张勃,何珺,华正伸,鲁豪祺,王新,彭会芬.MoO42-取代对Nasicon型Li3Fe2(PO4)3正极材料电化学性能的影响[J].无机化学学报,2016,32(12):2109-2116. |
查看全文 查看/发表评论 下载PDF阅读器 |
Support information: |
|
|
|