摘要
利用周期性体系的Hartree-Fock方法计算了以LiC6/LiNiO2锂离子二次电池的平均电压,结果与实验值相差+15%。计算表明,NiO2中嵌入一个Li原子变成LiNiO2后,负电荷主要从Li转移到O上,转移到Ni上的负电荷仅约20%,讨论了其对Jahn-Tell效应的影响。以Li0.5NiO2作为嵌锂中间物的代表,研究了锂离子的可能迁移路径。通过对NiO2和LiNiO2的电子态密度的计算,研究了NiO2在嵌锂过程中的能带变化及其对电极的电化学性质的影响。
The Li-Ni oxides as a cathode material for secondary lithium-ion batteries is studied by using the Hartrre-Fock method for periodic systems. The average open-circuit voltage of LiCe/LiNiO2 battery is calculated and compared with that experimentally observed. Our calculations reveal that the negative electric charge donated by a Li atom after its intercalation in NiO2 is mainly transferred to O. Only a small part (ca. 20%) is populated to Ni. Its influence on the Jahn-Teller effect is discussed. The possible migration pathways for Li+ ion in Li0.5NiO2 crystal are studied. The shift of energy bands caused by Li intercalation is observed by comparison of the calculated density of states for NiO2 and LiNiO2, and is used for explanation of their electric conductivity.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2003年第8期807-812,共6页
Chinese Journal of Inorganic Chemistry
