High-performance lithium storage based on the synergy of atomic-thickness nanosheets of TiO₂(B) and ultrafine Co₃O₄ nanoparticles

Lithium ion batteries (LIBs) are critical constituents of modern day vehicular and telecommunication technologies. Transition metal oxides and their composites have been extensively studied as potential electrode materials for LIBs. However, inefficient lithiation, poor electrical conductivity, and drastic volume change during cycling result in low reversible capacity and rapid capacity fading, and thus hinder the practical applications of those electrodes. In this work, we report a facile synthesis of a novel hierarchical composites, which consist of ultrafine Co₃O₄ nanoparticles uniformly dispersed on TiO₂(B) nanosheets with atomic thickness (Co₃O₄ NPs@TiO₂(B) NSs). When tested as anode material for LIBs, the Co₃O₄ NPs@TiO₂(B) NSs sample with optimized composition shows a reversible capacity of ∼677.3 mAhg^-1 after 80 cycles at a current density of 100 mAg^-1. A capacity of 386.2 mAhg^-1 is still achieved at 1000 mAg^-1. The synergistic effect of ultrafine Co₃O₄ nanoparticles and atomic-thickness TiO₂(B) nanosheets is responsible for the enhanced electrochemical performance.