摘要
采用密度泛函理论方法研究了锂离子正极材料LiMn2O4电子结构及金属掺杂对其平均嵌入电压的影响。嵌锂前后差电荷密度分析表明,Mn2O4嵌锂过程中,O、Mn均得到Li给出的电子,且以O得电子为主。Al3+和Sc3+取代LiMn2O4原胞中的Mn掺杂研究表明,Al3+和Sc3+在嵌锂过程中不参与和Li的电子交换,因而导致掺杂体系具有较大的嵌入电压。且Al3+、Sc3+掺杂导致LiMn2O4电极材料稳定性提高,材料密度减小,因此Al3+和Sc3+可作为较佳的锂离子正极掺杂材料。
The electronic structure and its effect on the average intercalation voltage for metal-doped LiMn204 lithium-ion cathode materials were obtained by a density functional theory study. The electron density difference in the lithium intercalation process shows that O and Mn atoms accept the electrons do- mated from Li atoms and the former is dominated. The A1- and Sc- doped LiMn204 ,namely the substitu- tion of Mn by a certain amount of AI3＋ or Sc9 ＋ , have higher average intercalation voltage, due to that AI3＋ and Sc3＋ do not participate in electronic exchange during the process of Li intercalation. Furthermore, the A1 or Sc doping can significantly increase the stability while reducing material density. As a consequence, AI3＋ and Sc＋ cations may serve as good lithium-ion cathode doping materials.
出处
《应用化工》
CAS
CSCD
2012年第7期1218-1223,共6页
Applied Chemical Industry
