Hierarchical macroporous Si/Sn composite: Easy preparation and optimized performances towards lithium storage

Hierarchical macroporous Si/Sn composites are fabricated via one facile and green dealloying process by etching SiSnAl alloy precursors. The as-made Si/Sn composites consist of three dimensional hierarchical macroporous Si network and bimodal pore channels as the built units with Sn nanoparticles uniformly distributed on the porous surface. Owing to its hierarchical porous architecture and incorporation of Sn nanoparticles, the Si85Sn15 sample delivers much higher specific capacity, superior cycling stability, and better rate capability compared with Si80Sn20 and pure Si anodes. The Si85Sn15 composite presents a steady capacity about 1600 mA h g(-1) at 200mA g(-1) in the period of 70 cycles. Even the current rates are set up to 3000 and 4000 mA g(-1), Si85Sn15 can still exhibit the high capacities of -800 and -620 mA h g(-1), respectively. In particular, the lithium storage performances of Si85Sn15 composite are superior to those of most other reported Si/Sn or Si/Sn-based anodes. The as-made Si/Sn composite shows the promising application prospect as an alternative anode candidate for lithium-ion batteries with the excellent performances and easy preparation. (c) 2019 Elsevier Ltd. All rights reserved.