氨基功能化石墨烯吸附锂原子的理论研究

• 作 者: 袁文彬 杨丽君
• 机 构: 西华师范大学化学化工学院,化学合成与污染控制四川省重点实验室,
• 出 处: 计算机与应用化学
• 发表日期: 2014年06期
• 关键词: 石墨烯 氨基功能化 储锂 电极材料

运用第一性原理计算方法,研究了氨基功能化石墨烯(G-NH_2)的特点及对锂原子的吸附情况。计算结果表明,G-NH_2为P型半导体,能隙0.54eV,有优良的导电性能;G-NH_2层间距大于3.4A,不会发生类似石墨烯的聚集行为,具有更好的稳定性。分析单个锂原子在石墨烯(G)和G-NH_2上的吸附,结果表明G对锂的吸附能为-1.77 eV,锂所带电荷为0.552;G-NH_2对锂的吸附能为(-2.43~-3.51)eV,锂所带电荷为0.546~0.639。因而G-NH_2对锂吸附作用更强、电荷转移性能更好。对比多个锂原子在G与G-NH_2上的吸附,G-NH_2比G对Li吸附强且吸附量更大。以上计算结果表明,与本征石墨烯相比,G-NH_2对锂原子有更强吸附作用,电荷转移性能更佳,储锂量更大。

First-principles calculations were used to investigate the characteristics of G-NH 2 and the adsorption of lithium atoms. The calculated results show that G-NH_2 is a P-type semiconductor and has an energy gap of 0.54eV. It has excellent conductivity. G-NH_2 layer spacing is greater than 3.4A, and graphene-like aggregation does not occur and has better stability. The adsorption of lithium on graphene (G) and G-NH_2 was analyzed. The results showed that the adsorption energy of lithium on G was -1.77 eV and the charge of lithium was 0.552. The adsorption energy of lithium on G-NH_2 was (-2.43 ~ -3.51) eV, the charge of lithium is 0.546 ~ 0.639. Thus, G-NH 2 adsorbs more strongly on lithium and has better charge-transfer properties. Comparing the adsorption of multiple lithium atoms on G and G-NH_2, G-NH_2 adsorbs more and adsorbs more Li than G. The above results show that, compared with intrinsic graphene, G-NH 2 has stronger adsorption of lithium atoms, better charge transfer performance and larger amount of lithium storage.