Abstract The need for sustainable and large-scale energy supply has led to significant development of renewable energy and energy storage technologies. Divalent metal ion (Mg, Ca, and Zn) batteries are promising energy storage technologies for the sustainable energy future, but the need for suitable electrode materials have limited their commercial development. This paper investigates, at the atomic scale, the adsorption and migration of Mg, Ca, and Zn on pristine and defective graphene surfaces, to bring insight into the metal storage and mobility in graphene and carbon-based anodes for divalent metal ion batteries. Such atomistic studies can help address the challenges facing the development of novel divalent metal battery technologies, and to understand the storage differences between divalent and monovalent metal-ion batteries. The adsorption of Ca on the graphene-based system is shown to be more energetically favorable than the adsorption of both Mg and Zn, with Ca showing adsorption behavior similar to the monovalent ions (Li, Na, and K). This was further investigated in terms of metal migration on the graphene surface, with much higher migration energy barriers for Ca than for Mg and Zn on the graphene systems, leading to the trapping of Ca at defect sites to a larger extent.

中文翻译：

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二价金属（Mg、Ca 和 Zn）在原始和缺陷石墨烯上的吸附和迁移行为

摘要 对可持续和大规模能源供应的需求导致了可再生能源和储能技术的重大发展。二价金属离子（镁、钙和锌）电池是可持续能源未来的有前途的储能技术，但对合适电极材料的需求限制了其商业发展。本文在原子尺度上研究了 Mg、Ca 和 Zn 在原始和有缺陷的石墨烯表面上的吸附和迁移，以深入了解二价金属离子电池的石墨烯和碳基负极中的金属存储和迁移。这种原子研究有助于解决新型二价金属电池技术发展面临的挑战，并了解二价和单价金属离子电池之间的存储差异。Ca 在基于石墨烯的系统上的吸附比 Mg 和 Zn 的吸附在能量上更有利，Ca 显示出类似于单价离子（Li、Na 和 K）的吸附行为。这在石墨烯表面上的金属迁移方面得到了进一步研究，在石墨烯系统上，Ca 的迁移能垒比 Mg 和 Zn 的迁移能垒高得多，导致在更大程度上捕获缺陷位点的 Ca。