Dual-Size Silicon Nanocrystal-Embedded SiOx Nanocomposite as a High-Capacity Lithium Storage Material

Abstract

SiOx-based materials attracted a great deal of attention as high-capacity Li+ storage materials for lithium-ion batteries due to their high reversible capacity and good cycle performance. However, these materials still suffer from low initial Coulombic efficiency as well as high production cost, which are associated with the complicated synthesis process. Here, we propose a dual-size Si nanocrystal-embedded SiOx, nanocomposite as a high-capacity Li+ storage material prepared via cost-effective sol-gel reaction of triethoxysilane with commercially available Si nanoparticles. In the proposed nanocomposite, dual-size Si nanocrystals are incorporated into the amorphous SiOx matrix, providing a high capacity (1914 mAh g(-1)) with a notably improved initial efficiency (73.6%) and stable cycle performance over 100 cycles. The highly robust electrochemical and mechanical properties of the dual-size Si nanocrystal-embedded SiOx nanocomposite presented here are mainly attributed to its peculiar nanoarchitecture. This study represents one of the most promising routes for advancing SiOx-based Li+ storage materials for practical use.This research was supported in part by the R&D Center for Valuable Recycling (Global-Top Environmental Technology Development Program, No. GT-11-C-01-080-0), funded by the Ministry of Environment, Korea, and by the Korea Institute of Energy Technology Evaluation and Planning (KETEP), which is funded by the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20128510010080)