Nitrogen-doped carbon nanotubes encapsulated Bi nanobuds for lithium based high-performance energy storage devices

Abstract Bi-based electrode materials with a high theoretical capacity of 3800 mAh cm-3 and low redox potential of Bi3+/Bi for lithium ion batteries (LIBs) have attracted great attention in energy storage materials. However, the complexity of the synthetic route, structural degradation and instability of the solid electrolyte interphase (SEI) caused by the huge volume change during charge-discharge process restricts its large-scale preparation and practical application, respectively. In this paper, the nitrogen doped carbon nanotubes (N-CNTs) optimal encapsulation Bi nanobuds (Bi@N-CNT) was constructed by a facile solvent grinding method and subsequent annealing reactions that addresses these issues. The one-dimensional encapsulation matrix of N-CNTs in the composites with a high conductivity, not only prevents the exfoliation of Bi nanoparticles and accommodates the volume changes, but also constructs a stable SEI during cycling. This Bi@N-CNT anode with large specific capacity of 452.5 mAh g-1 at 0.2 A g-1 after 100 cycles, unprecedented rate capability and prolonged cyclic life span (209.6 mAh g-1 at 3 A g-1 after 1000 cycles). This work provides a scalable, simple, and efficient evolutionary method for the production of Bi@N-CNT electrode materials, this composite can be used as a potential anode for LIBs, which has a certain enlightening significance for the preparation of other alloy-type anodes.