标题：Semimetallic Si3C as a high capacity anode material for advanced lithium ion batteries
作者：Dong, Yanru; Wei, Wei; Lv, Xingshuai; Huang, Baibiao; Dai, Ying
作者机构：[Dong, Yanru; Wei, Wei; Lv, Xingshuai; Huang, Baibiao; Dai, Ying] Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Peoples R China.
通讯作者：Wei, W;Dai, Y
通讯作者地址：[Wei, W; Dai, Y]Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Peoples R China.
来源：APPLIED SURFACE SCIENCE
关键词：Lithium-ion batteries; Si/C composites; 2D Si3C; Theoretical specific; capacity
摘要：In combination of the merits of Si- and C-based anode materials for lithium-ion batteries (LIBs), we propose and evaluate the potential of novel Si3C as an anode material, which consists of light silicon and carbon atoms and is characterized by a Dirac cone. The adsorption energy for lithium atom is identified to be -2.58 eV, which is large enough to ensure a good lithium adsorption stability during the (de)lithiation process. Our results reveal that the energy barrier for Li diffusion on Si3C is only 0.46 eV, indicative of a fast charge/discharge rate. In addition, Si3C exhibits a semimetallic nature with a great advantage in electrical conductivity. Remarkably, the fully lithiated phase of Si3C is (Li6Si3C)(2), corresponding to a theoretical specific capacity of 1675 mAh/g, almost 4.5 times higher than that of commercial graphite (375 mAh/g). Besides, the low open-circuit voltage (OCV) of (Li6Si3C)(2) is determined to be 0.2 V. These intriguing superiorities endow the Si3C a promising anode material for LIBs.