Electrochemical Properties of Si-Alloy/Graphite/Carbon Nanotubes Blending Electrode for Li-Ion Batteries
In this study, we made Si-alloy/Graphite/Single-walled Carbon nanotubes(SWCNTs) blending electrode and evaluate the electrochemical properties. In case of 8% of Si-alloy / 89% of Graphite / 0% SWCNT / 2% of SBR /1% of CMC electrode, the initial discharge capacity is 387mAh/g, initial the coulombic efficiency is 86.2% and the capacity retention after 50th cycle is 80.7%. In case of 8% of Si-alloy/89.7% of Graphite/ 0.3% SWCNT/ 2% of SBR /1% of CMC electrode, the initial discharge capacity is 393.5mAh/g, the initial coulombic efficiency is 88.4% and the discharge capacity retention after 50cycle is 99.2%.
This improvement in the electrochemical properties of the SWCNT added electrode was mainly attributed to the good electric contact between Si-alloy particles and graphite particles during cycles. In other words, the main cause of initial capacity lose in Si-alloy/Graphite blending electrode is to lose electric contact due to the volume change of Si-alloy. This result gives many hints to improve Si-based anode materials.