掺杂Y^3+的锂锰尖晶石的合成及其电化学性能研究

采用流变相反应法合成了掺杂稀土钇离子的锂锰尖晶石LiYxMn2-xO4，并对其 结构和电化学性能进行了初步研究。结果表明，当掺入的Y^3+的含量较低（x≤0. 02)时，得到的产物能保持完整的尖晶石结构，并表现出极佳的电化学性能。Y^3+ 的掺入使材料的循环稳定性能大幅度提高，而这种提高是源于Y^3+对尖晶石结构的 稳定作用。电极材料LiY0.02Mn1.98O4显示了最优的电化学性能，在0.2℃放电速率 下，其初始放电容量为118mA·h·g^-1，100次循环后仍能保持初始容量的98％。

Synthesis and Electrochemical Properties of Yttrium-doped Lithium Manganese Spinel

Yttrium-doped spinel LiY Mn_(2-x)O_4 with single phase were synthesized by rheological phase reaction method. The structural and electrochemical properties of the material were studied by XRD and electrochemical measurements. The data of XRD show that the limit of Y solubility is x≤0.02. The beneficial effect of Y is evident by way of improved cyclability, which is due to the structure stability of the yttrium-doped spinel. The electrode of LiY_0.02Mn_1.98O_4 shows excellent electrochemical properties with a first discharge capacity of 118mA·h·g~(-1) and retaining 98% of the initial capacity after 100 cycles at the current rate 0.2C.