In-Situ Synthesis of Porous SnO₂/SnS₂@PC Anode Material with High-Capacity Using Calcium Carbonate as Template for Lithium-Ion Batteries

Tin-based materials have emerged as promising anode candidates for advanced lithium-ion batteries(LIBs) due to their high theoretical capacity (e.g. 994 mAh/g for Li₄.₄Sn), moderate operating potential, and natural abundance. However, Tin-based materials suffer from severe volumeexpansion (>300%) and rapid capacity during cycling. In this work, a composite composed of tin-based materials and porous carbon (PC), i.e. SnO2/SnS2@PC, was in-situ synthesized to mitigate these challenges. The composite was obtained by high-temperature calcination of a mixture containing SnO2, pe troleum asphalt and calcium carbonate, where petroleum asphalt acted as the carbon and sulfur resource, calcium carbonate acted as a pore-forming template. The prepared SnO2/SnS2@PC composite possed a specific surface area of 190.5 m2·g-1 with total pore volume 0.386 cm3·g-1, and delivered an initial specific capacity of 1431 mAh·g-1 and retained 722 mAh·g-1 at 100th cycle at 0.2 A·g−1, which is nearly three folds that of the actual capacity(~260 mAh/g) of commercial graphite and thus shows a promising application in next-generation LIBs.