Sn nanoparticles embedded into porous hydrogel-derived pyrolytic carbon as composite anode materials for lithium-ion batteries

摘要

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) cm^(2)·s^(-1) than pure Sn and other Sn@PHDC electrodes.Those improvements can be partly ascribed to the fact that the hydrogelderived pyrolytic c arbon matrix can release the volume strain and enhance the electronic conductivity of the composite electrode,and partly to the fact that the porous hydrogelderived pyrolytic carbon matrix can suppress agglomerations of Sn nanoparticles and shorten Li^(+) diffusion paths.This work may provide a new appro ach for the improvement of Sn-based anode materials for lithium-ion batteries.