以往的研究证实, 采用PAM模板合成法合成的LiFePO4/C复合材料, 具有颗粒尺寸小, 倍率放电性能好, 电化学比容量较高等特点1. 本文在此基础上对复合材料进行体相掺杂高价金属离子, 所得掺杂基LiFe0.99M0.01PO4/C(M=Nd3+、Co3+、Cr3+、Mn3+)改性材料的比容量有了进一步提高. 研究结果表明, C/3充放电时, 复合LiFePO4/C的容量为108mAh·g-1, 而掺杂基LiFe0.99M0.01PO4/C的比容量分别提高到140、129、120和115mAh·G-1, 而且循环性能也非常稳定. 电导率研究表明, 体相掺杂使得体相电导率提高了5到7个数量级, 与文献值较为接近. XRD衍射图谱表明, 掺杂后各个材料的结构依然保持有序的橄榄石结构.
In latest studies we confirmed that the PAM (polyacrylamide) templated LiFePO4/C composite was nano-structured with better rate property and higher specific capacity, compared with the undoped LiFePO4. In this article we further synthesized metal ions doped phosphates by this templating method, and all the capacities of those LiFe0.99M0.01PO4/C (M=Nd3+、Co3+、Cr3+、Mn3+) composites were enhanced. When discharging at C/3 rate the capacity of LiFePO4/C composite was only 108mAh·g-1, while those of the doped LiFe0.99M0.01PO4/C were respectively 140, 129, 120 and 115mAh·g-1. And the cycliabilities were also stable. Researches show that the conductivities of those doped materials are improved by 5~7 magnitude, which are close to those in references. XRD
patterns show that those doped materials still remain their ordered olivine structure.
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