Micro-porous carbon coated Si@FeCO3 nanoflowers for high-performance lithium-ion batteries

As a natural material with abundant resources and excellent energy storage properties, silicon has garnered significant attention as an anode material for lithium-ion batteries. However, silicon's poor electrical conductivity and significant volumetric changes during the reaction process continue to hinder its impact on battery capacity. In this paper, we propose a novel method to mitigate the volumetric changes by preparing Si@FeCO3@micro-C cladding structures. The technique has a concise process, in which Si@FeCO3 nanoflower structures are synthesized by hydrothermal method, and a layer of RF resin is coated on its surface and annealed to obtain microporous carbon-coated Si@FeCO3@micro-C materials. This material maintains a reversible capacity of 1356.8 mAh g- 1 after 2500 cycles at a current density of 1 A g- 1 and 941.7 mAh g- 1 after 800 cycles at a current density of 0.1 A g- 1 . After 1000 cycles, the cross-sectional thickness increased by approximately 38.7%, indicating an effective limitation on the silicon's volume expansion.