Carbon-encapsulated Bi2Te3 derived from metal-organic framework as anode for highly durable lithium and sodium storage
© 2020 Elsevier B.V. Carbon-encapsulated Bi2Te3 (Bi2Te3@C) was successfully synthesized through a MOF-derived two-step facile process. First, Bi(BTC) (DMF)·DMF·(CH3OH)2 (Bi-BTC) was prepared by a solvothermal process and then converted into Bi2Te3@C composite by a simple tellurization reaction. As anode for lithium ion batteries (LIBs), the Bi2Te3@C electrode shows outstanding cycling stability with a specific discharge capacity of 738.5 mAh g−1 at 100 mA g−1 after 500 cycles. Meanwhile, the Bi2Te3@C composite also demonstrates a specific discharge capacity of 236.4 mAh g−1 at 100 mA g−1 after 100 cycles in sodium ion batteries (SIBs). The significant electrochemical performance in LIBs and SIBs is attributed to the nano size of Bi2Te3, which can not only reduce the migration path of electron and ions, but also tolerate the volume variations in the cycle life. Besides, the carbon derived from Bi-BTC can enhance the electrical conductivity of Bi2Te3 nanoparticles and prevent their agglomeration. Electrochemical kinetic analysis of Bi2Te3@C indicates the capacitive contribution accounts for a substantial part for the capacity, which can enhance the rate performance of Bi2Te3@C electrode. This work demonstrates that Bi2Te3@C has a promising application in practical lithium and sodium storage.