多孔碳纳米管纸负载中空硅微球作为阳极的高容量锂硅电池
High capacity lithium silicon battery with hollow Si microspheres loaded with porous carbon nanotubes as anode

为提高硅基锂离子电池的电化学性能，制备了一种多微孔结构的集流体。以纸纤维为基体，多壁碳纳米管（MWCNTs）为导电剂，制得MWCNTs/纸纤维复合多孔导电纸代替铜箔作为负极集流体。MWCNTs负载中空Si微球复合材料作为负极活性材料。FESEM分析显示，中空Si-MWCNTs复合活性物质均匀分布在MWCNTs构建的三维导电网络的孔隙中，从而保证了材料的结构稳定性和化学稳定性。所制备的中空Si-MWCNTs/纸纤维复合锂离子电池具有良好的循环稳定性和较高的比容量，同时具有可逆性。在0.02 C的电流密度下，循环30次后其比容量稳定在1 300 mAh/g。在3 C的大电流密度下，比容量仍可稳定保持在330 mAh/g。恢复0.25 C充放电后，容量恢复为1 150 mAh/g。 In order to improve the electrochemical performance of lithium ion battery, a porous conductive current collector was fabricated mixing multiwalled carbon nanotubes (MWCNTs) and cellulose fibers through vacuum filtration method. The cellulose fibers were used as the matrix and MWCNTs as the conductive agent. The porous conductive paper of MWCNTs/paper fiber was used as cathode current collector instead of copper foil. The hollow Si microsphere doped with MWCNTs was used as active materials. FESEM was used for characterization. The results show that active substances of hollow Si-MWCNTs are well dispersed in network of MWCNTs conductive paper, which ensures the structural stability and chemical stability at the same time. The results show excellent cyclic stability and higher specific capacity, and also reversible. The capacity of the lithium ion battery reachs 1 300 mAh/g after 30 cycles at a rate of 0.02 C. The capacity still maintain 330 mAh/g at the current density of 3 C. When the current density reduces to 0.25 C, the capacity can be restored to as high as 1 150 mAh/g. 江西省科技厅科研（20142BBE50071）；江西省教育厅（KJLD13006）