Improving Lithium Storage Properties of SiOx Nanosheets By Introducing MoO2 Nanoparticles

Abstract

Silicon oxides (SiOx) have been recognized as promising candidates to replace commercial graphite anode materials in lithium-ion batteries. Two-dimensional (2D) microstructure of SiOx nanosheets leads to high capacity retention with the excellent dimensional stability. However, they have the disadvantage of having low specific capacity and low initial Coulombic efficiency. Here, molybdenum dioxide (MoO2) nanoparticles were introduced to compensate for the shortcomings of SiOx nanosheets. MoO2 nanoparticles are chemically bonded to the surface of SiOx nanosheets by Mo-O-Si bond, as a result, showing the improved reversible capacity and initial Coulombic efficiency while maintaining the strength of SiOx nanosheets. The observed improvement can be explained by the synergistic effect resulted by the combination of SiOx nanosheets with zero-dimensional (0D) MoO2 nanoparticles. The former provides favorable microstructures and dimensional stability while the latter offers abnormal lithium storage sites and highly reversible phase transition. In the presentation, the improved lithium storage properties of 2D-SiOx/0D-MoO2 nanocomposites will be discussed in detail.