Abstract:

Three-dimensional interconnected CuGeO₃ nanosheets were directly grown on nickel foam (NF) substrates by in-situ generation method, and the CuGeO₃/NF was directly used as binder-free anodes for lithium ion batteries (LIBs). The microstructure and morphology of the materials were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscope. Electrochemical performance of CuGeO₃/NF and CuGeO₃ electrode was investigated. The results indicated that CuGeO₃/NF electrode exhibited better electrochemical performance in comparison with CuGeO₃ electrode. The CuGeO₃/NF electrode showed reversible capacity of 972mA·h/g at a current density of 0.2A/g after 500 cycles with capacity retention of 94.1% when the current density returned to 0.1A/g from 1A/g (578mA·h/g). CuGeO₃/NF electrode delivered a high capacity of 936mA·h/g. The superior electrochemical performance of the CuGeO₃/NF electrode can be attributed to three-dimensional conductive network of the Ni foam. Additionally, the Ni foam supported CuGeO₃ nanoflakes promoted fast electron and ion transport, and alleviated the volume change during the Li⁺ insertion/extraction process.

Key words: CuGeO₃ anodes, hydrothermal synthesis, nanosheets, electrochemical properties

摘要：

采用原位生长法，在泡沫镍（nickel foam，NF）基底上制备具有三维互连结构的CuGeO₃纳米片，直接将CuGeO₃/NF电极材料用作锂离子电池电极，省去了涂覆法制备粉末电极所需的高分子黏结剂。利用X射线衍射仪、X射线光电子能谱、扫描电镜和透射电镜分析了电极材料的结构和形貌，测试了CuGeO₃/NF和CuGeO₃两种负极材料的电化学性能。结果表明，与传统涂覆法制备的CuGeO₃粉末电极相比，CuGeO₃/NF无黏结剂型电极具有更好的循环性能和倍率性能。在0.2A/g电流密度下500次循环后，可逆比容量为972mA·h/g，容量保持率94.1%；在电流密度为1A/g时，可逆比容量为578mA·h/g，电流密度恢复至0.1A/g时，可逆比容量升高至936mA·h/g。CuGeO₃/NF电极材料良好的电化学性能归因于泡沫镍的三维导电网络结构。此外，泡沫镍负载CuGeO₃纳米片加快了嵌锂/脱锂过程中电子和离子的传输，缓解了活性物质的体积膨胀。

关键词: CuGeO₃负极材料, 水热合成, 纳米片, 电化学性能