Construction of MnCo-BTC@C Microspheres by Annealing a Bimetal–Organic Framework with Enhanced Lithium Storage

Because of their changeable structure and diversity of morphology, metal–organic frameworks (MOFs) have sparked great interest as anodes for Li-ion batteries (LIBs). However, the poor electrical conductivity of MOFs has limited their application in LIBs. Herein, a carbon-coated microspheric MnCo-BTC (MC-BTC@C) with a diameter of approximately 1.4 μm has been prepared by annealing a bimetal–organic framework. The MC-BTC@C microsphere anode retains a high capacity of 1176.4 mAh g–1 at 200 mA g–1 after 100 cycles and exhibits a good rate performance (315 mAh g–1 at 4000 mA g–1). Notably, a high capacity of 654 mAh g–1 is maintained after 300 cycles at 1000 mA g–1. In addition, electrochemical impedance spectroscopy (EIS) has been applied to investigate the electrochemical behavior of MC-BTC@C and MC-BTC, revealing that the MC-BTC@C microsphere shows faster Li+ transport kinetics. Consequently, this research provides a new avenue for the ingenious design of MOFs with carbon coating for the LIB anode.