| There has recently been great interest in lithium storage at the anode of Li-ion rechargeable battery in order to replace the carbon-based anode. Over the last two decades, carbon-based anode, especially graphite, was utilized as anode in lithium ion batteries because of its cyclic stability and coulombic efficiency. However, low capacity and the thermal runaway resulted from the solid electrolyte interface (SEI) formation on the graphite anode during charging and discharging cycles. This inhibited the further development of lithium ion batteries for Plug-in Hybrid Electrical Vehicle (PHEV) or Electrical Vehicle (EV) which demand both high energy and high power density.;The goal of this research was to develop the anode material, Silicon Oxycarbide (SixOyCz) and Silicon Carbonitride (SixCyNz), from Polymer Derived Ceramics (PDCs) for lithium-ion batteries application and to understand the thermodynamics and kinetics of intercalation mechanism in the host material. This includes as three main categories: (1) Characterization of PDCs, (2) measurement of electrochemical phenomena of PDCs anode in half-cell which used lithium foil as anode, (3) analysis of the lithium intercalation mechanism and diffusion coefficient in PDCs.;In this thesis, the first objective was to synthesize possible anode materials and construct the proper battery structure to experiment its intercalation and deintercalation behaviors. Also, various experiments such as cyclic stability, capacity retention and C-rate capability were performed in order to estimate the feasibility of PDCs as new anode materials for the next generation.;The second objective was to determine the reversible and irreversible capacity from different fraction of Si, C, O and N composition. Based on this analysis, the mixed bond sites in SixOyCz had higher reversible and irreversible capacity than the free carbon sites.;The third objective was to examine the hysteretic response of lithium intercalation to SiCO. According to the coulometric titration results on both traverses of the cycle, an intrinsic polarization was measured and this polarization-potential, which is measured to be 250--500mV, is attributed to a differential between the potential of Li-ions across the anode-electrolyte interface.;Finally, the kinetic property, diffusion coefficient, of lithium was studied when the lithium was intercalated and deintercalated into SiCO. Galvanostatic Intermittent Titration Technique (GITT) and Potentiostatic Intermittent Titration Technique (PITT) have been adapted to measure the diffusivity of lithium as a function of the lithium concentration in PDCs. |
