Graphite‐Based Composite Anodes with C−O−Nb Heterointerfaces Enable Fast Lithium Storage

Abstract

AbstractTo better satisfy the increasing demands for electric vehicles, it is crucial to develop fast‐charging lithium‐ion batteries (LIBs). However, the fast‐charging capability of commercial graphite anodes is limited by the sluggish Li+ insertion kinetics. Herein, we report a synergistic engineering of uniform nano‐sized T‐Nb2O5 particles on graphite (Gr@Nb2O5) with C−O−Nb heterointerfaces, which prevents the growth and aggregation of T‐Nb2O5 nanoparticles. Through detailed theoretical calculations and pair distribution function analysis, the stable existence of the heterointerfaces is proved, which can accelerate the electron/ion transport. These heterointerfaces endow Gr@Nb2O5 anodes with high ionic conductivity and excellent structural stability. Consequently, Gr@10‐Nb2O5 anode, where the mass ratio of T‐Nb2O5/graphite=10/100, exhibits excellent cyclic stability and incredible rate capabilities, with 100.5 mAh g−1 after 10000 stable cycles at an ultrahigh rate of 20 C. In addition, the synergistic Li+ storage mechanism is revealed by systematic electrochemical characterizations and in situ X‐ray diffraction. This work offers new insights to the reasonable design of fast‐charging graphite‐based anodes for the next generation of LIBs.