Perpustakaan Digital ITB

The increasing carbon dioxide (CO2) emissions from the energy and transportation sectors have accelerated vehicle electrification, thereby driving the growing demand for lithium-ion batteries (LIBs). Currently, commercial graphite-based anodes, with a specific capacity of ~372 mAh/g, are insufficient to meet the requirements of highcapacity LIBs. Graphite anodes also exhibit performance limitations at high current densities, making them less suitable for fast-charging applications needed in the development of batteries for electric vehicles. Compared to graphite anodes, silica (SiO2) is a promising alternative candidate due to its abundant availability, low cost, and significantly higher theoretical capacity (~1965 mAh/g). However, the application of SiO2-based anodes is still hindered by low electrical conductivity, poor initial coulombic efficiency, and significant volume expansion during cycling. These factors result in SiO2-based anodes performing far below their theoretical capacity and exhibiting low stability. In this research, a hybrid anode structure was designed by integrating silica particles into a carbon matrix derived from a metal-organic framework (MOF), specifically ZIF- 67. Additionally, nitrogen-doped carbon nanofibers sourced from melamine were grown on the surface of the hybrid anode to create conductive pathways, thereby enhancing the performance of the SiO2-based anode. The sample morphology was characterized using a field-emission scanning electron microscope (FESEM), while the elemental composition was analyzed through energy-dispersive X-ray spectroscopy (EDS). X-ray diffraction (XRD) and Raman spectroscopy were employed to analyze the crystal structure and phase formed. The silica-based electrode was fabricated using a mixed slurry method and subsequently coated onto a copper current collector. The electrode sheets were then assembled into coin-type battery cells (CR2032). To evaluate the electrochemical performance of the battery cells, a series of tests was conducted, including electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), cycling and long-term cycling performance, and rate capability tests. The experimental results demonstrated that structural modification effectively enhanced the electrochemical performance of the SiO2-based anode. Material characterization revealed that the modified samples exhibited improved morphology and higher crystallinity compared to the unmodified sample. The modified sample also demonstrates superior electrochemical performance, as evidenced by lower charge transfer resistance, higher lithium-ion diffusion coefficient, and more stable cycling performance. The SiO2@CoNC-CNF anode delivers outstanding performance, achieving a specific capacity of 245 mAh/g and a capacity retention of 134% after 1000 cycles at a current density of 1 A/g.