Pomegranate-like Sn-Ni nanoalloys@N-doped carbon nanocomposites as high-performance anode materials for Li-ion and Na-ion batteries

Sn-Ni nanoalloy@N-doped carbon nanocomposites with remarkable pomegranate-like architecture display outstanding lithium-ion and sodium-ion storage performances. • Pomegranate-like Sn-Ni nanoalloys@N-doped carbon nanocomposites were fabricated. • Sn-Ni@NC nanocomposites display exceptional Li + and Na + storage performances. • Unique structure can alleviate the volume change and provide fast transmission channels of ions. • Electrochemical kinetic analyses of Sn-Ni@NC nanocomposites were carried out. Tin-based alloy materials are one of the most promising anodes with high intrinsic electrical conductivity and superior capacity for lithium-ion batteries (LIBs) /sodium-ion batteries (SIBs). However, they are confronted with the obstacle of large volume dilatation and structural collapse during the insertion/deinsertion reactions of Li + /Na + . In this study, the three-dimensional (3D) pomegranate-like Sn-Ni nanoalloys@N-doped carbon nanocomposites are successfully synthesized. They deliver high discharge/charge capacities at 0.05 A g −1 (1117/846.4 mAh g −1 for LIBs; 539.4/319.7 mAh g −1 for SIBs) and exceptional cycling stability (330.7 mAh g −1 after 1000 cycles at 2.0. A g −1 for LIBs). These features may be attributed to the buffer effect of volume expansion by the unique 3D pomegranate-like architecture and the synergy effect between Sn-Ni nanoalloys and N-doped carbon for enhanced electrical conductivity. The electrochemical kinetics analyses of the Sn-Ni@NC electrode are performed to reveal the superior lithium-ion storage property. This work aims to design a kind of tin-based anode materials with superior electrochemical performances for LIBs and SIBs.