Bi@C sandwiched carbon nanolayers enables remarkable cyclability at high current density for lithium-ion batteries

Abstract

Large designs are devoted to decrease the volume fluctuation and pulverization of bismuth anodes. However, further advances in cycling stability at higher current density remain challenging. Herein, we skillfully designed a unique sandwich structure composed of bismuth nanoparticles coated with carbon nanolamella (Bi@C) and carbon nanolayers (C NL) via a simple pyrolysis method. Benefiting from the synergistic effect of the unique interlayer hybrid structure, the Bi@C composite material has an interconnected electron transportation pathway, which effectively alleviates the volume expansion during alloying/dealloying and reduces the agglomeration of the Bi particles during cycling. In addition, the Bi@C embedded in the double carbon layers structure (Bi@C/C NL) not only serve as highly conductive networks for Li+, but also provide a large surface area for electrolyte penetration and storage, which will enhance the charge transfer reaction kinetics process. As a result, the Bi@C/C NL-700 anode revealed a superior capacity (427.5 mAh g−1 at 500 mA g−1 after 300 cycles), excellent long cycling stability (373 mAh g−1 at 3 A g−1 after 1500 cycles) and improved rate performance, outperforming the most reported Bi-based anode materials for lithium-ion batteries. This work will lay an experimental foundation for the rational design of high-performance anode materials in rechargeable batteries with layered hybrid structures.