Sn@C Composite Architecture for Improved Stability and Performance in Lithium-Ion Battery Anodes

The theoretical capacity of metallic tin (Sn) is 994 mAh g−1, making it a promising anode material for lithium-ion batteries (LIBs). The cycling performance rapidly deteriorates due to the significant volume expansion and contraction during the lithium insertion/extraction process, which is the main limiting factor for the practical application of Sn-based anode materials in LIBs. We report a new material design and fabrication method for carbon-coated Sn solid sphere anodes, using amorphous carbon as the conductive and buffering matrix to form Sn@C composite materials. The size of the composite phases can be easily controlled by varying the carbon source ratio and reduction calcination temperature. The results show that the sample with a carbon source ratio of 1:4, reduced at 600 °C, exhibits excellent electrochemical performance. At a current density of 0.2 C, the discharge capacity reaches 994 mAh g−1 after 500 cycles. At a current density of 3 C, the capacity is maintained at 318 mAh g−1 after 1000 cycles. The synthesis of high-performance Sn-based anode materials through a simple and controllable method holds significant importance and value.