Functionalized Two-Dimensional Nanoporous Graphene as Efficient Global Anode Materials for Li-, Na-, K-, Mg-, and Ca-Ion Batteries
Functionalized Two-Dimensional Nanoporous Graphene as Efficient Global Anode Materials for Li-, Na-, K-, Mg-, and Ca-Ion Batteries
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DOI：
10.1021/acs.jpcc.0c01216
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发表时间：
2020-05-07
影响因子：
3.7
通讯作者：
Karton, Amir
中科院分区：
文献类型：
--
作者：
Hussain, Tanveer;Olsson, Emilia;Karton, Amir
二维纳米多孔石墨烯（NPG）是近年来合成的一种具有均匀分布纳米孔的材料，具有优异的电学、力学、热学和光学性能，在多个领域具有潜在的应用前景。在这里，我们探讨了NPG作为锂，钠，钾，镁和钙离子电池的阳极材料的潜在应用。我们使用密度泛函理论计算来研究NPG单分子膜的结构性质、缺陷形成能、金属结合能、电荷分析和电子结构。原始NPG可以有效地结合K+阳离子，但不能充分地强结合其他金属阳离子，这是高效阳极材料的先决条件。然而，在用富氧官能团（例如，O、OH和COOH）和掺杂杂原子（B、N、P和S），NPG的金属结合能力显著增强。在所考虑的系统中，S掺杂的NPG（S-NPG）与金属阳离子的结合最强，结合能为-3.87（Li）、-3.28（Na）、-3.37（K）、-3.68（Mg）和-4.97（Ca）eV，其次是P-NPG、O-NPG、B-NPG和N-NPG。在取代的NPG体系中，O取代的NPG表现出最强的金属结合力，结合能为-3.30（Li）、-2.62（Na）、-2.89（K）、-1.67（Mg）和-3.40 eV（Ca）。Bader电荷分析和Roby-Gould键指数表明，大量的电荷从金属阳离子转移到功能化的NPG单分子膜。电子性质进行了研究，通过态密度图，并发现所有的系统是金属后，引入金属阳离子。这些结果表明，官能化NPG可用作Li-、Na-、K-、Mg-和Ca-离子电池的全局阳极材料。
Two-dimensional nanoporous graphene (NPG) with uniformly distributed nanopores has been synthesized recently and shown remarkable electronic, mechanical, thermal, and optical properties with potential applications in several fields. Here, we explore the potential application of NPG as an anode material for Li-, Na-, K-, Mg-, and Ca-ion batteries. We use density functional theory calculations to study structural properties, defect formation energies, metal binding energies, charge analysis, and electronic structures of NPG monolayers. Pristine NPG can bind effectively K+ cations but cannot sufficiently bind the other metal cations strongly, which is a prerequisite of an efficient anode material. However, upon substitution with oxygen-rich functional groups (e.g., O, OH, and COOH) and doping with heteroatoms (B, N, P, and S), the metal binding ability of NPG is significantly enhanced. Of the considered systems, the S-doped NPG (S-NPG) binds the metal cations most strongly with binding energies of -3.87 (Li), -3.28 (Na), -3.37 (K), -3.68 (Mg), and -4.97 (Ca) eV, followed by P-NPG, O-NPG, B-NPG, and N-NPG. Of the substituted NPG systems, O-substituted NPG exhibits the strongest metal binding with binding energies of -3.30 (Li), -2.62 (Na), -2.89 (K), -1.67 (Mg), and -3.40 eV (Ca). Bader charge analysis and Roby-Gould bond indices show that a significant amount of charge is transferred from the metal cations to the functionalized NPG monolayers. Electronic properties were studied by density of states plots, and all the systems were found to be metallic upon the introduction of metal cations. These results suggest that functionalized NPG could be used as a global anode material for Li-, Na-, K-, Mg-, and Ca-ion batteries.