Open AccessEffect of bivalent metal element doping on the electronic transport properties of LiCoO2
Author(s) -
Sung-Chol Kim,
ZuFei Huang,
Xing Ming,
Chunzhong Wang,
Xing Meng,
Gang Chen
Publication year - 2007
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.56.6008
Subject(s) - doping , materials science , acceptor , band gap , fermi level , electronic structure , ionic bonding , condensed matter physics , ionic radius , electronic band structure , ion , valence (chemistry) , density of states , chemical physics , chemistry , optoelectronics , electron , physics , organic chemistry , quantum mechanics
In order to understand the different effects of Ca and Mg doping on the electronic transport properties of LiCoO2which is the primary cathode material in Li-ion secondary batteriesthe electronic structures of the relevant systems are studied with the ab initio method based on the density-functional theory. It is found that both Ca and Mg partial substitution for Co in LiCoO2 crystal will give rise to partially occupied acceptor band near the Fermi levelbut these bands are substantially localized. MoreoverCa-doped system has a clear energy gap between the acceptor band and the valence bandwhereas for the Mg-doped system there isn't such a gap. It's believed that the existence of this gap is the main factor resulting in the non-significant increase of the electronic conductivity in the Ca-doped LiCoO2. In additionthe remarkable distinction in the ionic radii of Ca2+ and Mg2+ can also induce noticeably different effects on the electronic conductivities.