The composite powders, Sn nanoparticles embedded into the porous hydrogel-derived carbon (Sn@PHDC), were successfully prepared by polymerization and calcination processes, and the characterization results confirmed that Sn nanoparticles were homogeneously dispersed in the porous hydrogel-derived pyrolytic carbon. The coin cell assembled with the Sn@PHDC-50 composite electrode presented good cyclic stability and rate performance when the weight ratio of Sn nanoparticles to hydrogel-derived pyrolytic carbon was maintained at 1:1. Moreover, the Sn@PHDC-50 electrode manifested a lower charge transfer resistance of 58.57 Ω and a higher lithium ions diffusion coefficient of 1.117 × 10^–14 cm²·s⁻¹ than pure Sn and other Sn@PHDC electrodes. Those improvements can be partly ascribed to the fact that the hydrogel-derived pyrolytic carbon matrix can release the volume strain and enhance the electronic conductivity of the composite electrode, and partly to the fact that the porous hydrogel-derived pyrolytic carbon matrix can suppress agglomerations of Sn nanoparticles and shorten Li⁺ diffusion paths. This work may provide a new approach for the improvement of Sn-based anode materials for lithium-ion batteries.

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