TiC3 Monolayer with High Specific Capacity for Sodium-Ion Batteries
TiC3 Monolayer with High Specific Capacity for Sodium-Ion Batteries
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高比容量 TiC3 单层钠离子电池
DOI：
10.1021/jacs.8b02016
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发表时间：
2018
影响因子：
15
通讯作者：
Guochun Yang
中科院分区：
文献类型：
--
作者：
Tong Yu;Ziyuan Zhao;Lulu Liu;Shoutao Zhang;Haiyang Xu;Guochun Yang
钠离子电池（SIB）由于本质安全和钠的高丰度而引起了相当大的关注。然而，缺乏高性能的阳极材料成为阻碍SIB发展的主要障碍。在这里，我们确定了一个理想的阳极材料，金属TiC 3单层不仅具有显着的高存储容量为1278 mA h g-1，但也低势垒能量和开路电压，通过第一性原理群集智能结构计算。TiC 3在吸附两层Na原子后仍保持金属性，保证了电池循环过程中良好的导电性。此外，高熔点和上级的动态稳定性有利于实际应用。其优异的性能主要归因于TiC 3单分子层中存在的一种特殊的联苯结构单元。高内聚能，源自多键共存（例如，共价，离子和金属键）的TiC 3单层，提供了实验合成的强大可行性。与TiC 3相比，氧功能化的TiC 3具有更高的储能容量，但其势垒能基本不变。这与富含金属的MXene形成鲜明对比。这些有趣的性能使TiC 3单层膜成为一种很有前途的SIB阳极材料。
Sodium-ion batteries (SIBs) have attracted considerable attention due to the intrinsic safety and high abundance of sodium. However, the lack of high-performance anode materials becomes a main obstacle for the development of SIBs. Here, we identify an ideal anode material, a metallic TiC3monolayer with not only remarkably high storage capacity of 1278 mA h g–1but also low barrier energy and open-circuit voltage, through first-principles swarm-intelligence structure calculations. TiC3still keeps metallic after adsorbing two-layer Na atoms, ensuring good electrical conductivity during the battery cycle. Besides, high melting point and superior dynamical stability are in favor of practical application. Its excellent performance can be mainly attributed to the presence of an unusualn-biphenyl unit in the TiC3monolayer. High cohesive energy, originating from multibonding coexistence (e.g., covalent, ionic, and metal bonds) in the TiC3monolayer, provides strong feasibility for experimental synthesis. In comparison with TiC3, functionalized TiC3with oxygen shows a higher storage capacity; meanwhile, it keeps nearly the same barrier energy. This is in sharp contrast with metal-rich MXenes. These intriguing properties make the TiC3monolayer a promising anode material for SIBs.