锌离子电池负极二维材料M2B2(M = Mo, Cr, Ti)的第一性原理研究

First-Principles Study of Two-Dimensional M2B2 (M = Mo, Cr, Ti) Materials as Anodes for Zinc-Ion Batteries

  • 摘要: 二维过渡金属硼化物(MBenes)因其优异的电化学性能,在储能领域具有广阔的应用前景。为提升可充电锌离子电池(ZIBs)的负极性能,本文采用第一性原理计算,系统研究了二维正交相(o-M2B2)与六方相(h-M2B2)的Mo2B2、Cr2B2和Ti2B2材料在ZIBs负极中的应用潜力。计算结果表明,o-M2B2与h-M2B2结构稳定且具有良好的导电性。o-M2B2与h-M2B2在同一过渡金属(M)下具有相同的Zn原子极限嵌入浓度,Mo2B2、Cr2B2和Ti2B2的理论比容量分别为502.03、853.40 和913.46 mA·h·g-1,与传统Zn负极相比,Cr2B2和Ti2B2作为锌离子电池负极具有更高的理论比容量。同时,Zn原子在h-Mo2B2、h-Cr2B2、h-Ti2B2和o-Ti2B2负极上都具有极低的扩散势垒分别为84、82、76和206 meV,表明其具有优异的离子扩散性能。综上,二维材料M2B2(M = Mo, Cr, Ti)是一种非常有前景的ZIBs负极材料。

     

    Abstract: Two-dimensional transition metal borides (MBenes) have demonstrated outstanding electrochemical properties, making them highly promising candidates for energy storage applications. To enhance the anode performance of rechargeable zinc-ion batteries (ZIBs), this study employs first-principles calculations to systematically investigate the application potential of orthorhombic (o-M2B2) and hexagonal (h-M2B2) phases of Mo2B2, Cr2B2, and Ti2B2. The results reveal that both o-M2B2 and h-M2B2 structures are thermodynamically stable and possess good electrical conductivity. For the same transition metal (M), o-M2B2 and h-M2B2 exhibit identical maximum zinc intercalation concentrations, corresponding to theoretical capacities of 502.03 mA·h·g−1 for Mo2B2, 853.40 mA·h·g−1 for Cr2B2, and 913.46 mA·h·g−1 for Ti2B2. Notably, Cr2B2 and Ti2B2 offer significantly higher theoretical capacities compared to conventional zinc anodes. In addition, Zn atoms exhibit very low diffusion barriers on h-Mo2B2 (84 meV), h-Cr2B2 (82 meV), h-Ti2B2 (76 meV), and o-Ti2B2 (206 meV), indicating excellent ion transport properties. These findings suggest that two-dimensional M2B2 (M = Mo, Cr, Ti) materials are highly promising anode candidates for ZIBs.

     

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