One-pot spray pyrolysis for core–shell structured Sn@SiOC anode nanocomposites that yield stable cycling in lithium-ion batteries

The core@shell-structured Sn@SiOC NPs were synthesized by one-pot spray pyrolysis. When applied as an anode material in LIBs, it shows a high reversible capacity and stable cycling performance. The results demonstrates that the Sn core offers high energy density while the SiOC effectively alleviates the volume expansion of Sn NPs and suppress the aggregation of Sn NPs during cycling. • Core-shell structured Sn@SiOC nanoparticles were synthesized by spray pyrolysis. • Sn@SiOC showed excellent electrochemical performances for Li-ion storage. • SiOC shell alleviated volume expansion and supresses aggregation during cycling. A novel strategy is reported for the synthesis of high-capacity anode materials with good cycling stability for use in lithium-ion batteries. A facile one-pot spray pyrolysis process is conducted using an ethanol solution of Sn acetate and diphenylsilanediol (DPSD). Phase separation between Sn and DPSD leads to the formation of core@shell-structured Sn@DPSD nanoparticles, and subsequent heat-treatment in an inert atmosphere carbonizes the DPSD to form Sn@SiOC nanoparticles (∼50 nm). When applied as an anode material in lithium-ion batteries (LIBs), the Sn core retains its high energy density, while the SiOC shell limits volume expansion of the core and protects it from pulverization and agglomeration. The Sn@SiOC nanoparticles exhibit a reversible capacity of 917 mA h g − 1 at 0.1C and stable cycling performance for 200 cycles at 1C. The nanoparticle formation mechanism is investigated by optimizing the Sn acetate/DPSD ratio in the precursor solution, and the origin of the enhanced properties is investigated by comparing the results of Sn@SiOC nanoparticles with those of SiOC nanoparticles and Sn microspheres. SiOC shows considerable promise as a coating material for Sn nanoparticles, which may serve as a milestone in the synthesis of nanosized electrode materials with coatings that can prolong the cycle lives of rechargeable batteries.