Two-Dimensional GaO/C Nanosheets as Durable and High-Rate Anode Material for Lithium Ion Batteries.

The self-healing feature of gallium (Ga) is unique, making Ga-based materials attract attention for their potential to solve the anode pulverization issue of lithium ion batteries. In this work, a hierarchical two-dimensional (2D) GaO/C structure has been synthesized by a facile NaCl template method. GaO nanoparticles (3.8 nm) are uniformly embedded in 2D carbon nanosheets. The long horizontal length of the carbon nanosheets (10 μm) provides long-range electron conductivity, and the thin vertical thickness (75 nm) shortens the Li ion diffusion path. Benefited from the integrated 2D structure and the high electron conductivity, the obtained 2D GaO/C nanosheets exhibit excellent overall performance, including high lithium storage capacity (1026 mAh g at 0.5 A g), high rate capability (378 mAh g at 10.0 A g), and high cyclability (500 cycles at 0.5 A g). The lithiation/delithiation mechanism of 2D GaO/C has been further studied with combined electrochemical and X-ray diffraction methods.