Bi nanoparticles in situ encapsulated by carbon film as high-performance anode materials for Li-ion batteries

Bismuth nanoparticles in situ encapsulated by carbon film (Bi@CF) was prepared successfully through a facile MOF-engaged approach, which exhibited high reversible capacity, long cycle life and robust rate capability for lithium-ion storage. Bismuth (Bi) has indeed inspired great interests in lithium-ion batteries (LIBs) due to the high capacity, but was still limited by the low electrical conductivity and large volume variation. Herein, a composite material based on Bi nanoparticles in situ encapsulated by carbon film (Bi@CF) is prepared successfully through a facile metal–organic framework (MOF)-engaged approach. As anode materials for LIBs, the Bi@CF composites achieved high reversible capacities of 705 and 538 mAh g −1 at 0.2 and 0.5 A g −1 after 200 cycles, and long cycling performance with a stable capacity of 306 mAh g −1 at 1.0 A g −1 even after 900 cycles. In situ X-ray diffraction (XRD) measurements clearly revealed the conversion between Bi and Li 3 Bi during the alloying/dealloying process, confirming the good electrochemical reversibility of Bi@CF for Li-storage. The reaction kinetics of this Bi@CF composite was further studied by galvanostatic intermittent titration technique (GITT). This work may provide an inspiration for the elaborate design and facile preparation of alloy-type anode materials for high-performance rechargeable batteries.