Although Li-ion batteries have different advantages, they suffer from short lifetime, high cost, and safety problems. The wide availability, multivalent character, and nontoxicity of magnesium suggest Mg-ion batteries (MIBs) as an alternative to Li-ion batteries. Here, we investigated the potential application of graphyne (as an alternative material to graphene) in the anode of MIBs at B3LYP and B3LYP-gCP-D3 levels. The adsorption energies of Mg and Mg²⁺ on graphyne were observed to be −6.1 and −223.6 kcal/mol, respectively. The dispersion term was predicted to be much more important for the Mg atom adsorption compared to the Mg²⁺ cation. The maximum energy barrier for the migration of Mg and Mg²⁺ over the graphyne surface was about 10.6 and 5.2 kcal/mol, respectively. The calculated cell voltage and specific storage capacity for graphyne respectively were 4.69 V and 558 mAh/g. The high cell voltage of MIBs is mostly attributed to the multivalent character of Mg atoms and strong cation–π interactions. Based on the results, the combination of high cell voltage, ultrahigh storage capacity, and good Mg mobility suggests graphyne as a promising anode substance in MIBs.

尽管锂离子电池具有不同的优点，但是它们具有寿命短，成本高和安全问题。镁的广泛可用性，多价特性和无毒性表明，镁离子电池（MIB）可以替代锂离子电池。在这里，我们研究了石墨烯（作为石墨烯的替代材料）在MIBs阳极中B3LYP和B3LYP-gCP-D3水平的潜在应用。观察到Mg和Mg ²⁺在石墨烯上的吸附能分别为-6.1和-223.6 kcal / mol。与Mg ²⁺阳离子相比，分散项对Mg原子的吸附更为重要。Mg和Mg ²⁺迁移的最大能垒石墨烯表面上的碳原子数分别约为10.6和5.2kcal / mol。所计算的石墨烯的电池电压和比存储容量分别为4.69 V和558 mAh / g。MIB的高电池电压主要归因于Mg原子的多价特性和强的阳离子-π相互作用。根据结果​​，高电池电压，超高存储容量和良好的Mg迁移率的组合表明石墨烯是MIB中有希望的阳极物质。