物理化学学报 >> 2022, Vol. 38 >> Issue (6): 2106002.doi: 10.3866/PKU.WHXB202106002

所属专题: 面向电化学储能与转化的表界面工程

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镶嵌于NH2-MIL-125 (Ti)衍生氮掺多孔碳中的花状超细纳米TiO2作为高活性和稳定性的锂离子电池负极材料

杨越1,2, 朱加伟1, 王鹏彦1, 刘海咪1, 曾炜豪1, 陈磊1, 陈志祥1, 木士春1,2,*()   

  1. 1 武汉理工大学,材料复合新技术国家重点实验室,武汉 430070
    2 佛山仙湖实验室,先进能源科学与技术广东省实验室佛山分中心,广东 佛山 528200
  • 收稿日期:2021-06-02 录用日期:2021-08-09 发布日期:2021-08-19
  • 通讯作者: 木士春 E-mail:msc@whut.edu.cn
  • 基金资助:
    国家重点研发计划(2016YFA0202603);国家自然科学基金(22075223)

NH2-MIL-125 (Ti) Derived Flower-Like Fine TiO2 Nanoparticles Implanted in N-doped Porous Carbon as an Anode with High Activity and Long Cycle Life for Lithium-Ion Batteries

Yue Yang1,2, Jiawei Zhu1, Pengyan Wang1, Haimi Liu1, Weihao Zeng1, Lei Chen1, Zhixiang Chen1, Shichun Mu1,2,*()   

  1. 1 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
    2 Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Xianhu Hydrogen Valley, Foshan 528200, Guangdong Province, China
  • Received:2021-06-02 Accepted:2021-08-09 Published:2021-08-19
  • Contact: Shichun Mu E-mail:msc@whut.edu.cn
  • About author:Shichun Mu, Email: msc@whut.edu.cn
  • Supported by:
    the National Key Research and Development Program of China(2016YFA0202603);the National Natural Science Foundation of China(22075223)

摘要:

由于具有高安全性和优异的循环稳定性,二氧化钛(TiO2)作为负极材料被广泛地应用于锂离子电池领域。但是较差的导电性和离子传输速率限制了TiO2的进一步应用和发展。鉴于此,我们以花状NH2-MIL-125 (Ti)为前驱体和硬模板,成功合成出了具有花状结构的超细纳米TiO2/多孔氮掺杂碳片(N-doped porous carbon)复合物(记为FL-TiO2/NPC)。过程中所制备的纳米TiO2-金属有机构架(Ti-MOF)展现出由二维褶皱多孔纳米片堆积、组装而成的花状结构。一方面,二维褶皱纳米片包含TiO2纳米颗粒可以增大活性物质与电解液的接触面积;另一方面,氮掺杂多孔碳基体可以提高整体复合物的导电性和结构完整性。将所获得的FL-TiO2/NPC作为负极组装成的锂半电池, 在0.5 A·g-1、300圈后仍有384.2 mAh·g-1以及在1 A·g-1、500圈仍有279.1 mAh·g-1的比容量。进一步性能测试表明,在2 A·g-1、2000圈长循环测试后,其仍能保持256.5 mAh·g-1的比容量和接近100%的库伦效率。该优异的电化学活性和稳定性主要起源于材料独特的花状结构。我们的合成策略为今后制备高储锂性能的金属氧化物/多孔氮掺杂碳负极提供了一种新的思路。

关键词: 纳米TiO2, 氮掺杂多孔碳纳米片, 花状结构, NH2-MIL-125(Ti), 负极, 锂离子电池

Abstract:

Owing to their advantages such as safe operation, high power density, long cycle life, and low self-discharge rate, lithium-ion batteries (LIBs) have attracted attention for applications ranging from portable electronics to electric vehicles (EVs)/hybrid EVs (HEVs). However, the striking exothermic reaction and growth of lithium dendrites during lithiation-delithiation cycles for commercial graphite anodes are hidden safety risks associated with LIBs. Titanium dioxide (TiO2) is considered as an important material for LIBs because of its high safety and excellent cycling stability. In addition, TiO2 anode used in lithium-ion storage system has a relatively high voltage (~1.5 V vs. Li/Li+), and thus, it meets the strict safety standards of commercial LIBs. However, the unsatisfactory conductivity and ion diffusion rate prevent the further application of TiO2 in LIBs. To date, the combination of graphene, carbon nanotubes (CNTs), carbon quantum dots (QDs) and porous carbon with TiO2 has attracted significant research attention. Nevertheless, it is still challenging to introduce a unique nanostructure design by organically compounding TiO2 with N-doped porous carbon matrix. Herein, N-doped porous carbon incorporating fine TiO2 nanoparticles (NPs) with a flower-like structure (denoted as FL-TiO2/NPC) is successfully prepared using flower-like NH2-MIL-125(Ti) as the hard template. The as-prepared Ti-based framework shows a flower-like structure, which is assembled with two-dimensional (2D) corrugated porous nanosheets. On the one hand, the corrugated carbon nanosheets incorporating fine TiO2 particles can offer a magnifying contact area between electrode matrix and electrolyte. On the other hand, the N-doped porous carbon plays a crucial role in improving the conductivity and structural integrity of the whole matrix. Therefore, the as-prepared FL-TiO2/NPC can deliver an excellent reversible lithium storage capacity of 384.2 mAh·g-1 at the current density of 0.5 A·g-1 after 300 cycles and 279.1 mAh·g-1 at 1 A·g-1 after 500 cycles. Furthermore, even when tested at 2 A·g-1, FL-TiO2/NPC can deliver a reversible capacity of 256.5 mAh·g-1 with a coulombic efficiency of 100% after 2000 cycles. The superior electrochemical performance and the structural toughness of LIBs originate from the unique flower-like structure. We believe that the proposed synthesis strategy will provide a new idea for the preparation of metal oxides/N-doped porous carbon composites with high lithium storage performance.

Key words: TiO2 nanoparticles, N-doped porous carbon nanosheet, Flower-like structure, NH2-MIL-125 (Ti), Anode, Lithium-ion battery

MSC2000: 

  • O643