论文标题
可充电电池阴极材料中LI插入电压的预测：交换相关功能，范德华的互动和Hubbard $ U $的影响
Prediction of Li intercalation voltages in rechargeable battery cathode materials: effects of exchange-correlation functional, van der Waals interactions, and Hubbard $U$
论文作者
论文摘要
对LI互联电压和可充电电池阴极材料的电子特性的定量预测是对第一原理理论的重大挑战，这是因为（1）与局部过渡金属$ d $电子和（2）在层次中的相互作用（VDW）相互作用的可能性很大，这两个层次的效果与标准的理论相关均未确定（vdw）相互作用，这是近距离捕获的，这是近距离捕获的，这是近距离捕获的，这是在标准的层面上，该（vdw）的相互作用恰好恰好是cortions of and coptiment。在这里，我们基于广泛使用的Perdew，Burke和Ernzerhof（PBE）的广义梯度近似以及电池阴极材料中广泛的严格约束和适当的元元元元化梯度近似值，对电子结构方法进行了系统的基准。 Studying layered Li$_x$TiS$_2$, Li$_x$NiO$_2$, and Li$_x$CoO$_2$, olivine Li$_x$FePO$_4$, and spinel Li$_x$Mn$_2$O$_4$, we compute the voltage, crystal structure, and electronic structure with and without extensions to incorporate on-site哈伯德相互作用和VDW相互作用。在纯dft（即没有对现场哈伯德相互作用的校正）中，扫描是描述阴极材料的PBE的显着改进，将平均绝对电压误差降低了50％以上。尽管显式VDW相互作用并不关键，并且在与扫描结合使用时甚至有害时，Hubbard $ u $校正对于与实验达成合理的一致性仍然是必要的。我们表明，此处没有考虑的单一方法可以准确地描述电池模型材料的电压，体积，体积，带隙和磁矩的误差（即，错误不超过5％）的电压和整体结构，电子和磁性特性，这激发了强大的需求，以改善此类系统的电子结构方法。
Quantitative predictions of the Li intercalation voltage and of the electronic properties of rechargeable battery cathode materials are a substantial challenge for first-principles theory due to the possibility of (1) strong correlations associated with localized transition metal $d$ electrons and (2) significant van der Waals (vdW) interactions in layered systems, both of which are not accurately captured by standard approximations to density functional theory (DFT). Here, we perform a systematic benchmark of electronic structure methods based on the widely-used generalized gradient approximation of Perdew, Burke, and Ernzerhof (PBE) and the new strongly constrained and appropriately normed (SCAN) meta-generalized gradient approximation for battery cathode materials. Studying layered Li$_x$TiS$_2$, Li$_x$NiO$_2$, and Li$_x$CoO$_2$, olivine Li$_x$FePO$_4$, and spinel Li$_x$Mn$_2$O$_4$, we compute the voltage, crystal structure, and electronic structure with and without extensions to incorporate on-site Hubbard interactions and vdW interactions. Within pure DFT (i.e., without corrections for on-site Hubbard interactions), SCAN is a significant improvement over PBE for describing cathode materials, decreasing the mean absolute voltage error by more than 50%. Although explicit vdW interactions are not critical and in cases even detrimental when applied in conjunction with SCAN, Hubbard $U$ corrections are still in general necessary to achieve reasonable agreement with experiment. We show that no single method considered here can accurately describe the voltage and overall structural, electronic, and magnetic properties (i.e., errors no more than 5% for voltage, volume, band gap, and magnetic moments) of battery cathode materials, motivating a strong need for improved electronic structure approaches for such systems.
