Wang Hewen, Wu Musheng, Tian Zhengfang, Xu Bo, Ouyang Chuying
College of Chemistry and Chemical Engineering, Hubei Key Laboratory for Processing and Application of Catalytic Materials, Huanggang Normal University, Huanggang, 438000, People's Republic of China.
Department of Physics, Laboratory of Computational Materials Physics, Jiangxi Normal University, Nanchang, 330022, People's Republic of China.
Nanoscale Res Lett. 2019 Jul 30;14(1):260. doi: 10.1186/s11671-019-3097-5.
From first principles calculations, a novel pentagonal Si/C complexity is predicted to have potential applications as a promising anode material for Li-ion batteries. It is found that the structural and thermal stability of the penta-siligraphene (P-SiC) is better than penta-graphene that is composed of C atoms only. Electronic band structure analysis shows that the empty C-2p state in the P-SiC provides space to accommodate and stabilize electrons from Li, which makes Li storage energetically favorable. As a result, four Li atoms can be stored by one formula unit of the P-SiC, corresponding to a theoretical gravimetric Li storage capacity of 1028.7 mAhg. The metallic electronic structures of the Li-adsorbed P-LiSiC as well as very small Li migration energy barriers are beneficial for fast charge/discharge performance of the battery. The mechanism on the Li adsorption interaction on the P-SiC is discussed. These results demonstrate a novel strategy to design two-dimensional Si/C complex anode materials for high-performance Li-ion batteries.
基于第一性原理计算，预测一种新型的五角形硅/碳复合物有望作为锂离子电池的阳极材料具有潜在应用价值。研究发现，五硅石墨烯（P-SiC）的结构和热稳定性优于仅由碳原子组成的五石墨烯。电子能带结构分析表明，P-SiC中未占据的C-2p态为容纳和稳定来自锂的电子提供了空间，这使得锂存储在能量上更有利。因此，一个P-SiC化学式单元可以存储四个锂原子，对应理论锂存储容量为1028.7 mAh/g。锂吸附的P-LiSiC的金属电子结构以及非常小的锂迁移能垒有利于电池的快速充放电性能。讨论了锂在P-SiC上的吸附相互作用机制。这些结果展示了一种设计用于高性能锂离子电池的二维硅/碳复合阳极材料的新策略。
