Proceedings of MATSUS Spring 2025 Conference (MATSUSSpring25)
DOI: https://doi.org/10.29363/nanoge.matsusspring.2025.359
Publication date: 16th December 2024
Silicon monoxide (SiO)-based anode materials are one of the most intensively investigated class of materials for use as high-capacity anodes in lithium-ion batteries. However, their low initial Coulombic efficiency (ICE), resulting from the irreversible electrochemical reaction of the amorphous SiO2 (a-SiO2) phase in the SiO, restricts the wide-spread adoption of SiO-based anode materials in lithium-ion batteries. In this work, we deomonstrate Si/M-silicate(M: Li, Mg, Ca) nanocomposite materials based on the dehydorgenation reaction of metal hydrides to improve the electrochemical performance of SiO. The resulting Si/M-silicate nanocomposite materials showed much improved electrochemical performance compared to pristine SiO. Laser-assisted atom probe tomography(LA-APT) combined with high resolution transmission microscopy(HR-TEM) clearly revealed that two exothermic reactions during prelihitation process related to microstructural evolution are key in optimizing the domain size of Si active phase and metal silicate buffer phase, and their topological arrangements in prelithiated SiO materials. We also report that the pre-emptive formation of irreversible phase combined with high-energy mechanical milling (HEMM) process can simultaneously improve both the ICE and long-term cycle performance by effectivley mitigating the volume expansion of Si during cycling, resulting in improved long-term cycle stability.