Large-Scale Fabrication of Egg-Carton-Inspired Bi/C Composite toward High Volumetric Capacity and Long-Life Lithium Ion Batteries

Nanostructuring strategies have immensely improved energy storage performance for Li ion batteries. However, the consequent low tap density and the severe side reaction caused by excessive specific surface area make it difficult for nanomaterials to exhibit satisfactory performance in their practical applications. Herein, inspired by the structural characteristics of egg cartons, a rational nanomicro structure was designed to address these problems. Specifically, compact micron-size 2D dimpled carbon frameworks (cartons) with densely distributed bismuth nanoparticles (eggs) were prepared via large-scale pyrolysis methods. The composite electrode exhibits a high volumetric capacity of 1461 mA h cm–3 at 100 mA g–1, which can outperform all reported Bi-based anodes so far and even be comparable to prevailing Si-based anodes. Furthermore, a high capacity retention of 89% can be maintained after 1000 cycles at 1 A g–1. The excellent electrochemical lithium-storage performances are attributed to the unique egg-carton-like hierarchical nanomicro structure with robust mechanical integrity and compact sheet morphology.