Yang Le, Hu Mingxiang, Zhang Hongwei, Yang Wen, Lv Ruitao
Key Laboratory of Cluster Science of Ministry of Education Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China; State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
J Colloid Interface Sci. 2020 Apr 15;566:257-264. doi: 10.1016/j.jcis.2020.01.085. Epub 2020 Jan 23.
Hard carbon is regarded as one of the most promising anode material for sodium-ion batteries in virtue of the low cost and stable framework. However, the correlation between pore structures of hard carbon and sodium-ion storage is still ambiguous. In this work, based on precise control of pore-size distribution, the capacity, ion diffusion, and initial Coulombic efficiency were improved. Meanwhile, the relationship between pore structure and capacity was investigated. Our result indicates that the micropores hinder ion diffusion and hardly ever accommodate Na ions, while mesopores facilitate Na ion intercalation. Hard carbon with negligible micropores and abundant mesopores delivers a maximum capacity of 283.7 mAh g at 20 mA g, which is 83% higher than that of micropore-rich one. Even after 320 cycles at 200 mA g, the capacity still remains 189.4 mAh g.
硬碳因其低成本和稳定的框架结构，被视为钠离子电池最具潜力的负极材料之一。然而，硬碳的孔隙结构与钠离子存储之间的关系仍不明确。在这项工作中，基于对孔径分布的精确控制，提高了容量、离子扩散速率和初始库仑效率。同时，研究了孔隙结构与容量之间的关系。我们的结果表明，微孔会阻碍离子扩散，几乎不能容纳钠离子，而中孔则有利于钠离子的嵌入。微孔可忽略不计且中孔丰富的硬碳在20 mA g的电流密度下可提供283.7 mAh g的最大容量，比富含微孔的硬碳高出83%。即使在200 mA g的电流密度下循环320次后，容量仍保持在189.4 mAh g。
