Dual-carbon-confined hydrangea-like SiO cluster for high-performance and stable lithium ion batteries

Abstract

Silicon monoxide (SiO) is regarded as a strong candidate for next-generation lithium ion battery anode materials because of its high energy density, low cost, and relatively low volume expansion compared to silicon (Si). However, the intrinsic low electrical conductivity and non-negligible volume expansion limit the practical application of SiO. Herein, dual-carbon-confined hydrangea-like SiO clusters are developed via chemical vapor deposition (CVD) growth, followed by a spray drying approach as a novel anode material for high-performance and stable lithium ion batteries. The evolution of the buffer layer along with sufficient void spaces to alleviate the volume expansion, besides the increased electrical conductivity, contributes to the improved discharge capacity of 1071 mAh g−1 after 200 cycles at a high current density of 0.75 A g−1 with a low expansion ratio of 9%. The distinct dual-carbon-confined hydrangea-like structure leads to synergistic improvements in battery performance, which will pave the way for promoting the commercial application of silicon-based anode materials.