无机材料学报

• 研究论文 •    

复合蛋黄壳型NiCo2V2O8@TiO2@NC材料用作锂离子电池负极研究

张宇婷, 李晓斌, 刘尊义, 李宁, 赵鹬   

  1. 兰州理工大学 石油化工学院,兰州 730050
  • 收稿日期:2024-12-31 修回日期:2025-03-19
  • 作者简介:张宇婷(1999-),女,硕士研究生.E-mail: 1252557015@qq.com
  • 基金资助:
    兰州市科技计划项目(2023-3-68)

Composite Yolk-shell NiCo2V2O8@TiO2@NC Material as Anode for Lithium-ion Batteries

ZHANG Yuting, LI Xiaobin, LIU Zunyi, LI Ning, ZHAO Yu   

  1. School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, China
  • Received:2024-12-31 Revised:2025-03-19
  • About author:ZHANG Yuting(1999-),female, Master candidate. E-mail: 1252557015@qq.com
  • Supported by:
    Lanzhou Science and Technology Plan Project (2023-3-68)

摘要: 过渡金属钒酸盐作为一种较有优势的锂离子电池负极材料,目前存在着导电性差、充放电过程体积剧烈变化而造成循环稳定性差等瓶颈问题。本研究采用分步包覆策略制备了具有多级复合核壳结构的NiCo2V2O8@TiO2@NC材料以改善此缺陷。首先以水热合成及离子交换法制备出蛋黄壳结构NiCo2V2O8纳米微球作为前驱体,继而在其表面包覆坚固的TiO2层和氮掺杂碳(NC)网络结构,成功制备出分级介孔纳米结构。特定的蛋黄壳纳米球结构可以为NiCo2V2O8提供丰富的Li+传输通道,而进一步包覆TiO2层,不仅增强了材料的稳定性和耐久性,还为其提供了额外的电化学活性位点。同时,引入氮掺杂碳网络结构,不仅提升了有序多级核壳NiCo2V2O8@TiO2@NC材料的导电性,还有助于增强电子的快速传输,进一步优化了材料的电化学性能。在最优条件下制备的锂离子电池负极材料,NiCo2V2O8@TiO2@NC-0.2的初始比容量达到1422.0 mAh∙g-1,500次循环后比容量依然保持在1011.9 mAh∙g-1,比容量保持率在71.2%,显示出高比容量、良好的倍率性能和出色的循环稳定性,使得该材料在能源存储器件中具有广阔的应用前景。

关键词: 核壳结构, 过渡金属钒酸盐, 锂离子电池, 电化学性能

Abstract: Transition metal vanadates, as an advantageous anode material for lithium-ion batteries, currently have bottlenecks such as unsatisfied conductivity and cycle stability caused by drastic volume changes during charging and discharging. In this study, NiCo2V2O8@TiO2@NC material with a multi-level composite core-shell structure was prepared using a step-by-step coating strategy to improve this defect. Initially, yolk-shell structured NiCo2V2O8 nanospheres were synthesized as the precursor through hydrothermal synthesis and ion exchange methods. Subsequently, a robust TiO2 layer and a nitrogen-doped carbon (NC) network structure were coated on the surface, resulting in the formation of a hierarchical mesoporous nanostructure. The specific yolk-shell nanosphere structure provides abundant channels for Li+ transport in NiCo2V2O8, a promising electrochemical active material. Further coating with a TiO2 layer not only enhances the stability and durability of the material, but also offers additional electrochemical active sites. Moreover, the introduction of the nitrogen-doped carbon network structure not only improves the conductivity of the ordered multi-level core-shell NiCo2V2O8@TiO2@NC material but also facilitates rapid electron transport, further optimizing its electrochemical performance. Lithium-ion battery anode materials prepared under optimal conditions, NiCo2V2O8@TiO2@NC-0.2 exhibited an initial specific capacity of 1422.0 mAh∙g-1, which remained 1011.9 mAh∙g-1 after 500 cycles, corresponding to a specific capacity retention rate of 71.2%. This material is demonstrated high specific capacity, good rate performance, and excellent cycle stability, displaying promising prospective for a wide range of applications in energy storage devices.

Key words: core-shell structure, transition metal oxides, lithium-ion battery, electrochemical performance

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