Fu Zhong-Heng, Chen Xiang, Yao Nan, Yu Le-Geng, Shen Xin, Shi Shaochen, Zhang Rui, Sha Zhengju, Feng Shuai, Xia Yu, Zhang Qiang
Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
ByteDance, Inc., Zhonghang Plaza, No. 43, North 3rd Ring West Road, Haidian District, Beijing 100086, China.
J Chem Phys. 2023 Jan 7;158(1):014702. doi: 10.1063/5.0131408.
Ion transport in solids is a key topic in solid-state ionics. It is critical but challenging to understand the relationship between material structures and ion transport. Nanochannels in crystals provide ion transport pathways, which are responsible for the fast ion transport in fast lithium (Li)-ion conductors. The controlled synthesis of carbon nanotubes (CNTs) provides a promising approach to artificially regulating nanochannels. Herein, the CNTs with a diameter of 5.5 Å are predicted to exhibit an ultralow Li-ion diffusion barrier of about 10 meV, much lower than those in routine solid electrolyte materials. Such a characteristic is attributed to the similar chemical environment of a Li ion during its diffusion based on atomic and electronic structure analyses. The concerted diffusion of Li ions ensures high ionic conductivities of CNTs. These results not only reveal the immense potential of CNTs for fast Li-ion transport but also provide a new understanding for rationally designing solid materials with high ionic conductivities.
固体中的离子传输是固态离子学的一个关键主题。理解材料结构与离子传输之间的关系至关重要但具有挑战性。晶体中的纳米通道提供离子传输途径，这是快速锂离子导体中快速离子传输的原因。碳纳米管（CNT）的可控合成提供了一种人工调节纳米通道的有前景的方法。在此，预测直径为5.5埃的碳纳米管表现出约10毫电子伏特的超低锂离子扩散势垒，远低于常规固体电解质材料中的势垒。基于原子和电子结构分析，这种特性归因于锂离子在扩散过程中相似的化学环境。锂离子的协同扩散确保了碳纳米管的高离子电导率。这些结果不仅揭示了碳纳米管在快速锂离子传输方面的巨大潜力，也为合理设计具有高离子电导率的固体材料提供了新的认识。
