Li Shun, Yang Ming, He Guijin, Qi Dongmei, Huang Jianguo
Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
School of Engineering, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China.
Materials (Basel). 2021 Jun 20;14(12):3411. doi: 10.3390/ma14123411.
A bio-inspired nanofibrous MnO-TiO-carbon composite was prepared by utilizing natural cellulosic substances (e.g., ordinary quantitative ashless filter paper) as both the carbon source and structural matrix. Mesoporous MnO nanosheets were densely immobilized on an ultrathin titania film precoated with cellulose-derived carbon nanofibers, which gave a hierarchical MnO-TiO-carbon nanoarchitecture and exhibited excellent electrochemical performances when used as an anodic material for lithium-ion batteries. The MnO-TiO-carbon composite with a MnO content of 47.28 wt % exhibited a specific discharge capacity of 677 mAh g after 130 repeated charge/discharge cycles at a current rate of 100 mA g. The contribution percentage of MnO in the composite material is equivalent to 95.1% of the theoretical capacity of MnO (1230 mAh g). The ultrathin TiO precoating layer with a thickness ca. 2 nm acts as a crucial interlayer that facilitates the growth of well-organized MnO nanosheets onto the surface of the titania-carbon nanofibers. Due to the interweaved network structures of the carbon nanofibers and the increased content of the immobilized MnO, the exfoliation and aggregation, as well as the large volume change of the MnO nanosheets, are significantly inhibited; thus, the MnO-TiO-carbon electrodes displayed outstanding cycling performance and a reversible rate capability during the Li insertion/extraction processes.
通过利用天然纤维素物质(如普通定量无灰滤纸)作为碳源和结构基质,制备了一种受生物启发的纳米纤维MnO-TiO-碳复合材料。介孔MnO纳米片密集地固定在预涂有纤维素衍生碳纳米纤维的超薄二氧化钛薄膜上,这形成了一种分级的MnO-TiO-碳纳米结构,并且当用作锂离子电池的阳极材料时表现出优异的电化学性能。MnO含量为47.28 wt%的MnO-TiO-碳复合材料在100 mA g的电流速率下经过130次重复充放电循环后,表现出677 mAh g的比放电容量。复合材料中MnO的贡献百分比相当于MnO理论容量(1230 mAh g)的95.1%。厚度约为2 nm的超薄TiO预涂层作为关键的中间层,促进了有序MnO纳米片在二氧化钛-碳纳米纤维表面的生长。由于碳纳米纤维的交织网络结构以及固定化MnO含量的增加,MnO纳米片的剥落和聚集以及大体积变化受到显著抑制;因此,MnO-TiO-碳电极在锂嵌入/脱出过程中表现出出色的循环性能和可逆倍率性能。