摘要
A watermelon-like internally inflated corebuffer-shell structural Si/electrochemically exfoliated graphene/C(Si/EG/C)composite is designed and prepared by the industrially established ball milling and spray drying method.Owing to numerous folds and voids in the EG filled between nano silicon and carbon shell,the volume fluctuations of silicon inside the Si/EG/C particles are buffered and lithium ions also could transport fast through the channels.With these advantages,the core-buffer-shell structural Si/EG/C composite demonstrates excellent electrochemical performance.The Si/EG/C anodes in half cells exhibit no degradation of the initial capacity(834 mA h g)after 100 cycles.Moreover,the Si/EG/C//LiCoOfull cells retain almost 100%of the initial discharge capacity after 500 cycles.These results highlight the potential applications of Si/EG/C in the next generation of Liion batteries.
本文采用球磨和喷雾干燥法,制备了类西瓜型可控内膨胀核-缓冲-壳结构Si/电化学剥离石墨烯/C(Si/EG/C)复合材料.在纳米硅和碳壳之间填充了含大量褶皱和空隙的EG,不仅缓冲了Si/EG/C颗粒内部硅的体积变化,还提供了锂离子的快速传输通道.凭借这些优势,核-缓冲-壳结构的Si/EG/C表现出优异的电化学性能.半电池中Si/EG/C负极在100次循环后相对于初始容量没有下降(834 mA h g^(-1)).此外,Si/EG/C//LiCoO_(2)全电池在500次循环后相对于初始放电容量的容量保持率接近100%.这些结果表明Si/EG/C在下一代锂离子电池中具有潜在应用前景.
基金
supported by the National Key R&D Program of China(2018YFB0905400)
the Key Laboratory Open Project of Guangdong Province(2018B030322001)
the National Natural Science Foundation of China(52172201,51732005 and 11905081)。
