Plasma enabled in-situ deposition of hybrid structured SiOx/C on polymorphous carbon hosts for superior lithium storage

Abstract

SiOx anode is a potential anode of lithium-ion batteries due to its lower cost, processability, and cycling stability. However, the application of SiOx is still limited by its low conductivity, large volume change and low initial Coulombic efficiency (ICE). This work employs the flexible and controllable active screen plasma to prepare a series of SiOx/C composites with high ICE and specific capacity. The comparative study demonstrates that SiOx/CMK-3 with a hybrid structure supported by the porous structure and three-dimensional carbon skeleton of CMK-3 exhibits better structural stability and higher SiOx loading. Through further temperature regulation, the optimized SiOx/CMK-3 exhibits high rate capability, high ICE (76.7%) and excellent cycling stability (618.9 mAh·g−1 after 4000 cycles at 1Ag-1). The morphology structure and electrochemical behavior analysis reveals that the high capacity and ICE are attributed to the protection of SiOx by nanostructured SiOx, porous carbon structures and SiOx shells, while the pores of CMK-3 can effectively suppress volume expansion and reduce contact with the electrolyte to prevent repeated generation of new SEI. In addition, the carbon matrix and mesoporous channels of CMK-3 endow SiOx/CMK-3 with high conductivity and diffusion kinetics. This study provides new ideas and methods for preparing high-performance silicon-carbon anodes.