Double conductivity-improved porous Sn/SnP@carbon nanocomposite as high performance anode in Lithium-ion batteries.

Carbon encapsulated porous Sn/SnP (Sn/SnP@C) composite is conveniently prepared by one-step electrochemical dealloying of SnP alloy in mild conditions followed by growing one carbon layer. Controllable dealloying of the SnP alloy results in the formation of bicontinuous spongy SnP nanostructure with a part of residued metallic Sn atoms embedded in the porous skeleton. A uniform carbon layer is deposited on the nanoporous Sn/SnP to prevent the nanostructure's pulverizing and agglomerating during lithium ion insertion/extraction. Upon double conductivity modification from metallic Sn matrix and carbon layer, the as-made composite displays superior lithium-storage performances with much higher specific capacity as well as better cycling stability compared with pure porous SnP. It offers a specific capacity of 837 mA h g after 100 cycles at a rate of 100 mA g. Even after 700 cycles at the higher rate of 1000 mA g, the specific capacity still maintains as high as 589 mA h g. The Sn/SnP@C material possesses promising application potential as an alternative anode in the lithium storage fields.