Blue phosphorene/ graphene heterostructure as a promising anode for lithium- ion batteries: a firstprinciples study with vibrational analysis techniques
Blue phosphorene/ graphene heterostructure as a promising anode for lithium- ion batteries: a firstprinciples study with vibrational analysis techniques
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蓝色磷烯/石墨烯异质结构作为锂离子电池有前景的阳极：振动分析技术的第一原理研究
DOI：
10.1039/c8ta09423c
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发表时间：
2019-01-14
影响因子：
11.9
通讯作者：
Ma, Fei
中科院分区：
文献类型：
--
作者：
Li, Yan;Wu, Wenting;Ma, Fei
范德华异质结构可以保持其各个组分的期望特征，并由于层间耦合而产生新的功能。本文基于色散校正密度泛函理论和振动分析技术，系统地研究了蓝色磷烯/石墨烯（BlueP/G）异质结构作为锂离子电池的潜在阳极。研究发现，石墨烯的半金属特性在蓝ep /G异质结构中得到了很好的保留，使其具有良好的导电性能，可以进行快速电子传递。与原始的蓝ep和石墨烯单层相比，由于界面协同效应，蓝ep /G体系中Li的结合能大大增加。因此，理论比容量可达626 mA h g(-1)，甚至超过了黑色磷烯/ g异质结构（485 mA h g(-1)）。Li在BlueP/G体系上的最小扩散势垒仅为0.13 eV，室温扩散率为2.61 x 10(-5) cm(2) s(-1)，比石墨烯快了两个数量级。振动对离子扩散的影响与材料有关，而且是显著的。更重要的是，BlueP/G异质结构及其电荷产物在353-422 N m（-1）范围内具有超高的刚度，并且在充满电的情况下，其有效体积膨胀极小，仅为10.89%，这可能会缓解锂化过程中通常与巨大体积膨胀/收缩相关的安全问题。这些结果表明，BlueP/G异质结构具有优异的导电性、对锂离子的强吸附和快速扩散、高能量容量和超高的机械稳定性等优点，有望成为高性能锂离子电池的正极材料。
van der Waals heterostructures can preserve the desired features of their individual components and induce new functions due to interlayer coupling. In this work, based on the dispersion-corrected density functional theory and vibrational analysis techniques, the blue phosphorene/graphene (BlueP/G) heterostructure was systematically studied as a potential anode for Li-ion batteries. It was found that the semi-metal characteristics of graphene are well preserved in the BlueP/G heterostructure, endowing it with excellent electrical conductance for fast electron transport. The binding energy of Li in the BlueP/G system is greatly increased due to the interfacial synergistic effect, as compared to pristine BlueP and graphene monolayers. Consequently, the theoretical specific capacity can be up to 626 mA h g(-1), even exceeding that of the black phosphorene/G heterostructure (485 mA h g(-1)). The minimum diffusion barrier of Li on the BlueP/G system is only 0.13 eV, resulting in a room-temperature diffusivity of 2.61 x 10(-5) cm(2) s(-1), which is two orders of magnitude faster than that on graphene. The impact of the vibrational contribution on the ionic diffusion is material-dependent and significant. More importantly, the BlueP/G heterostructure and its charge products display ultrahigh stiffness in the range of 353-422 N m(-1) and an extremely small effective volume expansion of 10.89% for the fully charged product, which might alleviate the safety concerns commonly associated with huge volume expansion/contraction upon lithiation. These results demonstrate that the BlueP/G heterostructure could be a promising anode material for high-performance Li-ion batteries due to its excellent conductivity, strong adsorption and fast diffusion of Li, high energy capacity, and ultrahigh mechanical stability.