Bismuth/bismuth trioxide with a dual-carbon support for high and long life lithium storage

Bismuth (Bi) is regarded as a prospective candidate for new lithium-ion battery anodes, but its capacity and cycle life need to be improved. Even with design and preparation of various Bi/carbon (Bi/C) nanocomposites, the performance improvement of the Bi for lithium-ion battery anode is still not unfavorable. Herein, the peculiar dual-carbon supporting nanostructured architecture has been fabricated for the first time and demonstrated to be highly effective in improving the lithium storage of the Bi anode. This as-fabricated characteristic Bi/C nanocomposite is composed of Bi nanoparticles (containing small amounts of bismuth trioxide (Bi2O3)) with sizes ranging from 10 to 50 nm encapsulated within capsule-like porous carbon matrixes, which are further interlinked with amorphous porous carbon (PC) coated carbon nanotubes (CNT). This composite is therefore denoted as CNT@Bi/Bi2O3@PC. The results demonstrate that the well-designed architecture endows the as-fabricated composite with superior structural stability and improved electrochemical kinetics. As a result, the CNT@Bi/Bi2O3@PC displays unprecedented lithium storage performance, delivering high capacity of 513 mAh g−1 at 200 mA g−1 after 600 cycles and 232 mAh g−1 at 1000 mA g−1 after even 2500 cycles. Moreover, thus unprecedented performance of the CNT@Bi/Bi2O3@PC in association with its architecture advantages can offer inspiration for rational design of other nanostructured alloying-based anodes toward advanced lithium storage.