Single source precursor-derived SiOC/TiOxCy as an anode component for Li-ion batteries

Amorphous silicon oxycarbides are known to be an effective anode material for lithium-ion batteries. Despite their exceptional properties and high charge capacities, however, their practical uses are limited by their significant first-cycle loss, considerable hysteresis, and low cyclic ability. Comparatively, SiOC/metal oxide materials have demonstrated increased rate capability and cyclic stability. This study utilized a liquid precursor-derived ceramic method to modify SiOC with titanium (IV) butoxide precursor to synthesize SiOC/TiOxCy. X-ray diffractograms confirmed the amorphous nature of SiOC/TiOxCy. The elemental composition and bonding properties were investigated using X-ray photoelectron spectroscopy, and electron microscopy was used to explore morphological features. In the first cycle, the reversible capacity of pyrolyzed SiOC/TiOxCy was 520 mAh g(-1), which then increased to 736 mAh g(-1) for the 1200 degrees C annealed SiOC/TiOxCy due to the increased free carbon network and TiC conductive phases. The irreversible capacity of the first cycle was 568 mAh g(-1), which was lower than the annealed SiOC irreversible capacity of 695 mAh g(-1). Interestingly, the rate stability of the pyrolyzed SiOC/TiOxCy performed more stability than the annealed sample. Localized carbothermal reactions between amorphous SiOC/TiOxCy and free carbon at annealing temperatures resulted in loss of structure stability.