Designing of high capacity Si nanosheets anode electrodes for lithium batteries

Despite extensive studies for the last several decades, commercialization of silicon based anode materials for high-capacity batteries is slow. In particular, silicon demonstrates the rapid volumetric changes result in drastic capacity degradation for rechargeable lithium-ion batteries (LIBs). Here, we evaluate uniformly carbon-coated Si nanosheets (C-SiNSs) as effective anode materials in LIBs. We utilize the parylene C, an insulation polymer, to make a coating with a uniform thickness on the SiNSs using the chemical vapor deposition (CVD) method at room temperature. The synthesis method of the C-SiNSs includes a simple pyrolysis process at 950 °C after the uniformed parylene C coating on SiNSs. Particularly, the C-SiNSs coated with 10 nm carbon for anode material improve the capacity and the cycle performance (~2100 mAh g⁻¹ for the 300^th cycle at 0.15 C-rate) with approximately 100 % coulombic efficiency.