Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292, USA.
Nanotechnology. 2017 Feb 17;28(7):075401. doi: 10.1088/1361-6528/aa52ac. Epub 2017 Jan 12.
To completely understand lithium adsorption, diffusion, and capacity on the surface of phosphorene and, therefore, the prospects of phosphorene as an anode material for high-performance lithium-ion batteries (LIBs), we carried out density-functional-theory calculations and studied the lithium adsorption energy landscape, the lithium diffusion mobility, the lithium intercalation, and the lithium capacity of phosphorene. We also carried out, for the very first time, experimental measurement of the lithium capacity of phosphorene. Our calculations show that the lithium diffusion mobility along the zigzag direction in the valley of phosphorene was about 7 to 11 orders of magnitude faster than that along the other directions, indicating its ultrafast and anisotropic diffusivity. The lithium intercalation in phosphorene was studied by considering various Li P configurations (n = 1-16) including single-side and double-side adsorptions. We found that phosphorene could accommodate up to a ratio of one Li per P atom (i.e. LiP). In particular, we found that, even at a high Li concentration (e.g. x = 1 in Li P), there was no lithium clustering, and the structure of phosphorene (when fractured) is reversible during lithium intercalation. The theoretical value of the lithium capacity for a monolayer phosphorene is predicted to be above 433 mAh g, depending on whether Li atoms are adsorbed on the single side or the double side of phosphorene. Our experimental measurement of the lithium capacity for few-layer phosphorene networks shows a reversible stable value of ∼453 mAh g even after 50 cycles. Our results clearly show that phosphorene, compared to graphene and other two-dimensional materials, has great promise as a novel anode material for high-performance LIBs.
为了全面了解磷烯表面上锂的吸附、扩散和容量，从而探索磷烯作为高性能锂离子电池（LIB）的阳极材料的前景，我们进行了密度泛函理论计算，并研究了锂在磷烯表面的吸附能、锂扩散迁移率、锂嵌入以及锂容量。我们还首次对磷烯的锂容量进行了实验测量。我们的计算表明，在磷烯谷的锯齿方向上，锂的扩散迁移率比其他方向快 7 到 11 个数量级，这表明其具有超快和各向异性的扩散率。通过考虑各种 LiP 配置（n = 1-16），包括单侧和双侧吸附，我们研究了磷烯中的锂嵌入。我们发现，磷烯最多可以容纳一个磷原子（即 LiP）的锂。特别是，我们发现，即使在高锂浓度（例如 LiP 中的 x = 1）下，也没有锂聚集，并且在锂嵌入过程中磷烯的结构（在断裂时）是可逆的。预测单层磷烯的锂容量理论值超过 433 mAh g ，具体取决于锂原子是吸附在磷烯的单侧还是双侧。我们对少层磷烯网络的锂容量的实验测量表明，即使在 50 次循环后，也有一个约为 453 mAh g 的可逆稳定值。我们的研究结果清楚地表明，与石墨烯和其他二维材料相比，磷烯作为高性能 LIBs 的新型阳极材料具有很大的潜力。
