Liu Yaxiong, Guo Xing, Liu Xingchen, Huang Dongmei, Tian Xiaodong, Guo Quangui, Liu Zhanjun
CAS Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Institutional Center for Shared Technologies and Facilities/State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan 030001, China.
J Colloid Interface Sci. 2024 Dec;675:870-882. doi: 10.1016/j.jcis.2024.07.082. Epub 2024 Jul 10.
Microstructural engineering is regarded as a promising option for fabricating high-performance carbon anodes. Hence, a facile solvothermal-assisted low-temperature calcination strategy was employed to modulate the microstructure of semicoke-derived carbon anodes. Owing to the effective pseudo-graphite phase modulation, the modified carbon anode exhibited a significant increase in capacity, cycling stability and ion kinetics in both lithium-ion batteries and sodium-ion batteries. Kinetic analysis and in-situ X-ray diffraction confirmed the "adsorption and intercalation" energy storage mechanism of the obtained carbon electrodes. In addition, by investigating the energy storage mechanism, we found that increasing the pseudo-graphite phase proportion played different roles in lithium and sodium ions storage. For lithium-ion storage, the pseudo-graphitic phase preferentially promotes lithium-ion transport kinetics. Conversely, during sodium-ion storage, this particular structure markedly augments the embedding capacity of sodium. Theoretical calculations demonstrate that different patterns of variation in the activation energy with the carbon layer spacing of lithium/sodium intercalation compounds lead to differences in performance enhancement. This study not only offers a low-cost approach for preparing carbon anodes enriched with a pseudo-graphitic phase, but also provides new insight into the discrepancy between lithium ion and sodium ion storage.
微观结构工程被认为是制备高性能碳阳极的一种有前景的选择。因此，采用了一种简便的溶剂热辅助低温煅烧策略来调控半焦衍生碳阳极的微观结构。由于有效的准石墨相调制，改性碳阳极在锂离子电池和钠离子电池中的容量、循环稳定性和离子动力学都有显著提高。动力学分析和原位X射线衍射证实了所制备碳电极的“吸附和嵌入”储能机制。此外，通过研究储能机制，我们发现增加准石墨相比例在锂和钠离子存储中发挥了不同作用。对于锂离子存储，准石墨相优先促进锂离子传输动力学。相反，在钠离子存储过程中，这种特殊结构显著提高了钠的嵌入容量。理论计算表明，锂/钠插层化合物的活化能随碳层间距的不同变化模式导致了性能提升的差异。本研究不仅提供了一种制备富含准石墨相碳阳极的低成本方法，还为锂离子和钠离子存储之间的差异提供了新的见解。
