Nitrogen-Doped Carbon-Coated SnO2/Sn Nanocomposites by Supercritical Hydrothermal Synthesis as Advanced Anodes for Lithium-Ion Batteries

The SnO2 anode has a significant volume expansion and low conductivity for lithium-ion batteries (LIBs), which seriously hinder its commercial application in LIBs. Therefore, it is necessary to innovate the design and preparation methods and synthesize high-performance SnO2-based nanocomposite anode materials. For this purpose, we report the preparation of SnO2/Sn and nitrogen-doped carbon (SnO2/Sn@N-C) composite materials for LIB electrodes via supercritical hydrothermal synthesis and the hydrothermal method. The composite anode material was characterized by transmission electron microscopy, and ultrafine SnO2 and Sn nanoparticles were found to be uniformly distributed on the carbon matrix. Compared with original SnO2, the addition of nitrogen-doped carbon improved the overall performance of the electrode. Therefore, the synthesized SnO2/Sn@N-C composite materials have good cycling performance, and the reversible capacity was 523.7 mAh g–1 after 50 cycles at 0.1C and 416.8 mAh g–1 after 400 cycles at 1C.