MOF衍生中空核壳型Ni-Co-P@TiO2-x负极材料设计合成与储钠特性研究

Binary transition metal phosphide is expected to be a kind of promising anode material of Na-ion batteries due to its high theoretical specific capacity and suitable working potential. However, the practical application of binary transition metal phosphide is mainly hindered by its low electronic/ionic conductivity and severe volume expansion during sodiation-disodiation process. In this project, hollow core-shell Ni-Co-P@TiO2-x composite materials are synthesized through ionic etching-hydrolysis-hydrogenation/phosphidation. The rapid cooperative transmission of electrons and sodium ions can be realized by high efficiency electron-ion hybrid conductive network which was built by carbonized-MOF skeleton and oxygen-defect TiO2-x coating layer. The ionic conductivity will be enhanced with utilizing the hollow structure of the composite. Moreover, the volume expansion effect can be effectively inhibited by TiO2-x coating, and the enhanced structure stability is achieved. Consequently, the composite anode materials of Na-ion batteries with stable structure and excellent electrochemical performance are obtained. In addition, the study will clearly show the modification mechanism. This project can provide new ideas for the development and application of the electrode materials for Na-ion batteries.

双金属磷化物因其较高理论比容量和适宜的工作电位，成为一种非常具有发展前景的钠离子电池负极材料。然而较低电子/离子电导率和脱嵌钠过程严重的体积膨胀效应抑制了其有效应用。本项目通过离子刻蚀-水解-氢化/磷化法合成中空核壳型Ni-Co-P@TiO2-x复合材料：利用MOF碳化骨架和缺陷TiO2-x层形成的高效电子/离子混合导电网络实现电子和Na+的快速协同运输；利用中空结构的设计提高材料离子电导率；利用氧缺陷TiO2-x的均匀包覆提升材料结构稳定性、有效抑制脱嵌钠过程材料体积膨胀效应。通过本项目的研究，明晰上述改性机理，最终获得结构稳定、电化学性能优异的钠离子电池负极材料，并为新型电极材料的开发提供新的思路。

双金属磷化物因其较高理论比容量和适宜的工作电位，成为一种非常具有发展前景的钠离子电池负极材料。然而较低电子/离子电导率和脱嵌钠过程严重的体积膨胀效应抑制了其有效应用。本项目通过离子刻蚀-水解-氢化/磷化法合成中空核壳型Ni-Co-P@TiO2-x复合材料：利用MOF碳化骨架和缺陷TiO2-x层形成的高效电子/离子混合导电网络实现电子和Na+的快速协同运输；利用中空结构的设计提高材料离子电导率；利用氧缺陷TiO2-x的均匀包覆提升材料结构稳定性、有效抑制脱嵌钠过程材料体积膨胀效应。通过本项目的研究，明晰上述改性机理，最终获得结构稳定、电化学性能优异的钠离子电池负极材料，并为新型电极材料的开发提供新的思路。在本项目实施过程中共发表学术论文13篇，其中1篇入选ESI高被引论文，申请国家发明专利3项（其中已授权1项），培养硕士研究生3名。