Zhang Junbo, Lu Xiaodong, Zhang Jingjing, Li Han, Huang Bowen, Chen Bingbing, Zhou Jianqiu, Jing Suming
Department of Energy Science and Engineering, Nanjing Tech University, Nanjing, China.
Department of Electric Power Engineering, Nanjing Normal University Taizhou College, Taizhou, China.
Front Chem. 2021 May 10;9:677620. doi: 10.3389/fchem.2021.677620. eCollection 2021.
Layered structure (MoS) has the potential use as an anode in metal-ions (M-ions) batteries. Here, first-principles calculations are used to systematically investigate the diffusion mechanisms and structural changes of MoS as anode in lithium (Li)-, sodium (Na)-, magnesium (Mg)- and Zinc (Zn)-ions batteries. Li and Na ions are shown to be stored in the MoS anode material due to the strong adsorption energies (~-2.25 eV), in contrast to a relatively weak adsorption of Mg and Zn ions for the pristine MoS. To rationalize the results, we evaluate the charge transfer from the M-ions to the MoS anode, and find a significant hybridization between the adsorbed atoms and S atoms in the MoS anode. Furthermore, the migration energy barriers of M ions are explored using first-principles with the climbing image nudged elastic band (CINEB) method, and the migration energy barrier is in the order of Zn > Mg > Li > Na ions. Our results combined with the electrochemical performance experiments show that Li- and Na-ions batteries have good cycle and rate performance due to low ions migration energy barrier and high storage capability. However, the MoS anode shows poor electrochemical performance in Zn- and Mg-ions batteries, especially Zn-ion batteries. Further analysis reveals that the MoS structure undergoes the phase transformation from 2H to 1T during the intercalation of Li and Na ions, leading to strong interaction between M ions and the anode, and thus higher electrochemical performance, which, however, is difficult to occur in Mg- and Zn-ions batteries. This work focuses on the theoretical aspects of M-ions intercalation, and our findings may stimulate the experimental work for the intercalation of multi-ions to maximize the capacity of anode in M-ions batteries.
层状结构（MoS）有潜力用作金属离子（M离子）电池的负极。在此，采用第一性原理计算系统地研究了MoS作为锂（Li）、钠（Na）、镁（Mg）和锌（Zn）离子电池负极时的扩散机制和结构变化。结果表明，Li和Na离子由于具有较强的吸附能（约-2.25 eV）而存储在MoS负极材料中，相比之下，原始MoS对Mg和Zn离子的吸附较弱。为合理解释这些结果，我们评估了从M离子到MoS负极的电荷转移，并发现吸附原子与MoS负极中的S原子之间存在显著的杂化。此外，使用爬山图像推挤弹性带（CINEB）方法通过第一性原理探索了M离子的迁移能垒，迁移能垒顺序为Zn > Mg > Li > Na离子。我们的结果与电化学性能实验相结合表明，Li和Na离子电池由于离子迁移能垒低和存储能力高而具有良好的循环和倍率性能。然而，MoS负极在Zn和Mg离子电池中，尤其是在Zn离子电池中，表现出较差的电化学性能。进一步分析表明，在Li和Na离子嵌入过程中，MoS结构从2H相转变为1T相，导致M离子与负极之间有强相互作用，从而具有更高的电化学性能，然而，这种情况在Mg和Zn离子电池中很难发生。这项工作聚焦于M离子嵌入的理论方面，我们的发现可能会推动多离子嵌入的实验工作，以最大化M离子电池负极的容量。
