Assessment of 2H–SiC based intercalation compound for use as anode in lithium ion batteries
Assessment of 2H–SiC based intercalation compound for use as anode in lithium ion batteries
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DOI：
10.1016/j.ceramint.2019.10.280
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发表时间：
2020-03
影响因子：
5.2
通讯作者：
A. Majid;Syeda Afrinish Fatima;S. Khan;Z. Almutairi
中科院分区：
文献类型：
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作者：
A. Majid;Syeda Afrinish Fatima;S. Khan;Z. Almutairi
改进电极材料以升级锂离子电池（LIB）是与能源设备相关的研究的核心。在此，我们报告的前景，使用2H-SiC作为阳极材料的LIB的第一性原理为基础的理论预测的基础上。高对称性结构位的能量分布表明，与碳的四面体构型有关的位TC是插入主体中的有利位。发现Li与化学计量比以及非化学计量比的2H-SiC的反应是吸热的，这指出它们不适合于LIB中的锂化过程。然而，在Si单空位的存在下，Li嵌入到主体中出现了放热过程，这促使我们对该系统进行详细研究。发现嵌入到主体中之后的Li原子被电离，从而将其2s电子贡献给碳原子。对于以超级电池Li x Si 15 C 16形式模拟的主体，锂插入电压和理论容量的平均值分别计算为1.87 V和85 mA h/g。当锂原子沿沿着结晶a轴移动时，当它沿着连接六方环的路径通过碳原子时，锂原子所面临的扩散势垒最小（在这里考虑的所有路径中）。另一方面，在沿着c轴运动的情况下，对于沿着Tc位的最小能量路径，发现了类似的结果。低扩散屏障将促进锂离子快速移动，这表明电池的快速充电能力。
The improvement in electrode materials to upgrade lithium ion battery (LIB) is at heart of research related to energy devices. Herein, we report on the prospects of using 2H–SiC as an anode material in LIB on the basis of first principles based theoretical predictions. The energy profiling of high symmetry structural sites pointed out that the site T C related to tetrahedral configuration with carbon is favorable intercalation site in the host. The reaction of Li with stoichiometric as well as non-stoichiometric 2H–SiC are found endothermic which points to their unsuitability for lithiation process in LIBs. However, Li intercalation into the host in presence of Si monovacancy appeared an exothermic process which motivated us to study this system in detail. The Li atom after intercalation into the host is found ionized thereby donating its 2s electron to carbon atoms. The average value of the lithium insertion voltage and theoretical capacity are calculated as 1.87 V and 85 mA h/g respectively for the host simulated in the form of supercell Li x Si 15 C 16. The diffusion barrier faced by lithium atom while moving along crystalline a-axis is minimum (among all the paths considered here) when it follows a path that links hexagonal rings while passing carbon atoms. On the other hand, in case of motion along c-axis, similar results are found for minimum energy path that is along Tc site. The low diffusion barrier will facilitate the lithium ion to move quickly that points to fast charging capability of the battery.