The Effect of Binder on the Electrochemical Property of Silicon/carbon Anode

In this research, needle coke, graphite and silicon nanosheet were bonded by pitch or glucose to prepare the Si/C composite anode. The influence of binder on the microstructure and electrochemical property of Si/C anode was discussed. The sample using pitch as binder has smooth surface and is densely coated by pitch. The silicon is exposed on the surface of Si/C compound using glucose as the binder. Compared with pitch-based Si/C anode, glucose-based Si/C anode shows higher initial capacity and coulombic efficiency, but it’s capacity retention ratio is lower. The initial capacity, initial coulombic efficiency and capacity after 100 cycles of the glucose-based anode are 655.3 mAh/g, 70.3% and 474.0 mAh/g, respectively. Those of pitch-based anode are 555.8 mAh/g, 62.4% and 538.8 mAh/g, respectively. Using different binders leads to distinct microstructure, impedance and irreversible reaction, which finally causes the varying capacities and initial coulombic efficiency of anodes