掺杂元素对LiNi1-yMyO2嵌锂电位影响的解析

对锂离子蓄电池正极材料LiNiO2掺杂Co和M(M代表Al,Mg,Mn)等元素进行了研究,掺杂元素的引入在改善LiNiO2的电化学性能的同时,对其嵌锂电位也有重要的影响。Co的掺入降低了LiNiO2的嵌锂电位,Co和M的共同引入能减小Co对LiNiO2电位的降低作用。较低能量的化合物体系有助于获得较高的嵌锂电位。部分Co对LiNiO2进行掺杂时,t2g和eg*能级升高,同时Co的掺入稳定了NiO2的结构,降低了结构中Jahn-Teller效应,体系能量升高,导致LiNi1-yCoyO2的嵌锂电位较低。另外讨论了不同掺杂元素(Al,Mg,Mn)对LiNiO2掺杂后体系能量及嵌锂电位的变化。

Explanation of the effect of doping on intercalation potential of cathode materials LiNil-yMyO2

The doping of Co and M(Al, Mg, Mn) can not only improve the electrochemical performance of the cathode material LiNiO2, but also effect their intercalation potential directly. The results of experiments show that the intercalation potential of LiNiO2 was lowered by the doping of cobalt, but co-doping of Co and M(Al, Mg, Mn) improved the intercalation potential. Lower the energy of system is helpful to increase its intercalation potential. Doping cobalt into LiNiO2 can increase the energy of t2g and eg* and decrease the effect of Jahn-Teller, resulting the increasing of the system energy, therefore decrease the potential of LiNi1-yCoyO2. The effect of the co-doping Co-M (Al, Mg, Mn) on the intercalation potential of LiNiO2 were discussed in detail.