Analysis of the reason for capacity loss of Si/C anode

Si/C anode was used in 14500 cylindrical Li-ion battery. Some basic performance of the battery was studied by comparing the battery with carbon anode which used in the commercial battery widely. The existing problem in usage and the reason of the capacity loss of this material with cycle was studied. The retention of the 14500 battery with Si/C anode only was 69.5% after 200 cycles, the reason of why the capacity deteriorated quickly were: the active material peeled off from the current collector which was caused by the expansion of volume, and the electric contact became poor; SEI was destroyed due to volume expansion of the anode, and the electrolyte decomposed continuously resulting in the incrassation of passivation film and increasement of the resistance; it was not easy to extract all inserted lithium ions from Si.