储能科学与技术 ›› 2023, Vol. 12 ›› Issue (5): 1616-1624.doi: 10.19799/j.cnki.2095-4239.2023.0146

• 储能材料与器件 • 上一篇    下一篇

基于天然纤维素物质的C/TiO2/CuMoO4 微-纳结构复合纤维材料构筑及其电化学性能

张吉栋(), 杨展, 黄建国()   

  1. 浙江大学化学系，浙江 杭州 310058
  • 收稿日期:2023-03-15 修回日期:2023-03-20 出版日期:2023-05-05 发布日期:2023-05-29
  • 通讯作者: 黄建国 E-mail:22037076@zju.edu.cn;jghuang@zju.edu.cn
  • 作者简介:张吉栋（1992—），男，硕士研究生，研究方向为锂离子电池负极材料，E-mail：22037076@zju.edu.cn。
  • 基金资助:
    浙江省自然科学基金项目(LY16B010001)

Fabrication and electrochemical performance of micro-nanostructured C/TiO2/CuMoO4 fibrous composite based on natural cellulose

Jidong ZHANG(), Zhan YANG, Jianguo HUANG()   

  1. Department of Chemistry, Zhejiang University, Hangzhou 310058, Zhejiang, China
  • Received:2023-03-15 Revised:2023-03-20 Online:2023-05-05 Published:2023-05-29
  • Contact: Jianguo HUANG E-mail:22037076@zju.edu.cn;jghuang@zju.edu.cn

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摘要：

锂离子电池作为目前常见的储能器件，具有能量密度高、功率密度大、价格低廉、绿色环保等特点，已经得到广泛应用。目前发展非石墨基负极材料以提升电池性能的需求日益迫切，钼酸铜由于理论比容量高、还原电位低，是一种极具潜力的负极材料。本研究工作以天然棉花纤维为结构支架和碳源构建了一种具有微-纳结构的C/TiO2/CuMoO4复合纤维材料，解决了钼酸铜作为电极材料时导电性差和易粉碎的问题，表现出优异的电化学性能。首先对棉花纤维进行酸碱预处理提高其比表面积；然后通过溶胶-凝胶法在纤维表面沉积超薄二氧化钛层；再利用层层自组装(LbL)技术沉积钼酸铜层；最后在氩气氛围中于500 ℃煅烧6 h得到微-纳结构的C/TiO2/CuMoO4复合纤维材料。当用作电极材料时，在100 mA/g的电流密度下，钼酸铜质量分数为22.8%的复合材料首圈放/充电比容量分别为1212 mAh/g和675 mAh/g，库仑效率为55.7%，经过200圈循环后，其比容量为403 mAh/g，保持率为59.7%，具有良好的循环性能和倍率性能。这种微-纳结构提高了复合材料的导电性和稳定性，从而增强了其电化学性能。

关键词: 锂离子电池, 微-纳结构, 负极材料, 钼酸铜, 电化学性能

Abstract:

Lithium-ion batteries (LIBs) have been widely applied as common energy storage devices owing to their high energy and power densities, low cost, environmental friendliness, etc. The demand for developing nongraphite-based anode materials to improve battery performance is increasingly urgent. CuMoO4 is a potential anodic material owing to its high theoretical specific capacity and low reduction potential. To address the problems of poor electrical conductivity and irreversible structural pulverization when CuMoO4 is used as an anodic material, micro-nanostructured C/TiO2/CuMoO4 fibrous composite was fabricated using natural cotton fibers as the structural scaffold and C source, showing excellent electrochemical performance. The cotton fibers were first pretreated with H2SO4 and NaOH to increase the specific surface area, and thereafter, ultrathin TiO2 layers were deposited on the fiber surfaces using a sol-gel method. The CuMoO4 layers were further deposited via the layer-by-layer (LbL) self-assembly technique. The micro-nanostructure C/TiO2/CuMoO4 fibrous composite was obtained via calcination at 500 ℃ in an Ar atmosphere for 6 h. When applied as an anodic material for LIBs, the composite with 22.8% CuMoO4 delivered initial discharge and charge capacities of 1212 mAh/g and 675 mAh/g, respectively, with a coulomb efficiency of 55.7%; after 200 charge-discharge cycles at 100 mA/g, the specific capacity was 403 mAh/g with a capacity retention of 59.7%, showing good cycle and rate performances. The conductivity and structural stability of the composite are improved owing to its micro-nanostructure, enhancing electrochemical performances.

Key words: lithium-ion batteries, micro-nanostructure, anodic material, copper molybdate, electrochemical performance

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