Novel Si Based Composite Materials as Anodes for Energy Storage

Silicon anode is a promising candidate for lithium ion batteries (LIBs). Unfortunately, its commercial application is hindered by the low conductivity and poor structural stability due to the large volume expansion after lithium insertion. Porous structured silicon/carbon (Si/C) composites are promising anode materials for LIBs because of the high conductivity from the carbon matrix and the introduced inside void space which can absorb the big volume expansion of silicon nanoparticles (Si NPs) during charging/discharging processes, leading to improved rate performance and cycling stability. Three different porous structured Si/C anode materials in which silicon nanoparticles uniformly embedded inside the porous carbon matrix were prepared in this doctoral thesis. Acetylene, polyacrylonitrile (PAN) and oleic acid were employed as three different carbon resources to produce the carbon matrix. In addition, we used two different templating methods to prepare the sacrificial coating layers on the outer surface of silicon nanoparticles (Si NPs) and create the final porous structure after acid washing processes.