Influence of the exchange-correlation potential and magnetic properties on the Li2FeSiO4 cathode materials
Influence of the exchange-correlation potential and magnetic properties on the Li2FeSiO4 cathode materials
复制标题
DOI：
10.1016/j.commatsci.2019.04.053
复制
发表时间：
2019-10
影响因子：
3.3
通讯作者：
Dongxiao Lian;Yu-hong Zhao;H. Hou;Shuo Wang;Zhiqin Wen;Qian Zhang;Guo Qingwei
中科院分区：
文献类型：
--
作者：
Dongxiao Lian;Yu-hong Zhao;H. Hou;Shuo Wang;Zhiqin Wen;Qian Zhang;Guo Qingwei
本文利用密度泛函理论（DFT）对Li_2FeSiO_4化合物的电子结构、电化学性质、力学性质和热力学性质进行了研究（GGA + SP，GGA）和针对现场库仑相互作用校正的磁性或非磁性DFT（GGA + U + SP，GGA + U），以允许直接比较四种方法。就其结构特征而言，非磁性方案不能正确描述它们，而磁性方案可以。然而，像在GGA + SP和GGA + U + SP方法中，对于不同的磁性方案，在微观细节的描述上的精度是不同的。在电化学和电子学性质方面，由于电子结构的重置，只有GGA + U + SP的结果与实验值相符。结果表明，在GGA + U + SP近似下，增强的局域化效应和自旋极化效应对重现聚阴离子化合物的实验性质是必不可少的.此外，我们还发现交换关联势和磁性的诱导效应对聚阴离子化合物的热力学性质也有一定的影响。
Seen the interest in the application of the density-functional theory (DFT) calculations to reproduce the experimentally observed properties of the potential electrode materials, we consider the electronic structure, electrochemical properties, mechanical and thermodynamic properties of the Li2FeSiO4compound using magnetic or non-magnetic gradient-corrected density-functional theory (GGA + SP, GGA) and magnetic or non-magnetic DFT corrected for on-site Coulomb interactions (GGA + U + SP, GGA + U) to allow a direct comparison of the four methods. In terms of the structural characteristics, the non-magnetic scheme cannot correctly describe them, but magnetic scheme can. However, like in GGA + SP and GGA + U + SP method, the accuracy is different in the description of the microscopic details for different magnetic schemes. As for electrochemical and electronic properties, only GGA + U + SP results are in line with the experimental values due to the reset of the electronic structure. The results show that both enhanced localization and spin-polarized effects present in the GGA + U + SP approximation are essential to reproduce the experimentally observed properties of the polyanionic compounds. Furthermore, we found that the inductive effect of the exchange correlation potential and magnetic properties also has some effect on the thermodynamic properties of the polyanionic compounds.