Double conductivity-improved porous Sn/Sn₄P₃@carbon nanocomposite as high performance anode in Lithium-ion batteries

Carbon encapsulated porous Sn/Sn₄P₃ (Sn/Sn₄P₃@C) composite is conveniently prepared by one-step electrochemical dealloying of Sn₈₀P₂₀ alloy in mild conditions followed by growing one carbon layer. Controllable dealloying of the Sn₈₀P₂₀ alloy results in the formation of bicontinuous spongy Sn₄P₃ nanostructure with a part of residued metallic Sn atoms embedded in the porous skeleton. A uniform carbon layer is deposited on the nanoporous Sn/Sn₄P₃ 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 Sn₄P₃. It offers a specific capacity of 837 mA h g^-1 after 100 cycles at a rate of 100 mA g^-1. Even after 700 cycles at the higher rate of 1000 mA g^-1, the specific capacity still maintains as high as 589 mA h g^-1. The Sn/Sn₄P₃@C material possesses promising application potential as an alternative anode in the lithium storage fields.