Electronic Structure Modulation in MoO2/MoP Heterostructure to Induce Fast Electronic/Ionic Diffusion Kinetics for Lithium Storage

Abstract

Abstract Transition metal oxides (TMOs) are considered as the prospective anode materials in lithium‐ion batteries (LIBs). Nevertheless, the disadvantages, including large volume variation and poor electrical conductivity, obstruct these materials to meet the needs of practical application. Well‐designed mesoporous nanostructures and electronic structure modulation can enhance the electron/Li‐ions diffusion kinetics. Herein, a unique mesoporous molybdenum dioxide/molybdenum phosphide heterostructure nanobelts (meso‐MoO2/MoP‐NBs) composed of uniform nanoparticles is obtained by one‐step phosphorization process. The Mott–Schottky tests and density functional theory calculations demonstrated that meso‐MoO2/MoP‐NBs possesses superior electronic conductivity. The detailed lithium storage mechanism (solid solution reaction for MoP and partial conversion for MoO2), small change ratio of crystal structure and fast electronic/ionic diffusion behavior of meso‐MoO2/MoP‐NBs are systematically investigated by operando X‐ray diffraction, ex situ transmission electron microscopy, and kinetic analysis. Benefiting from the synergistic effects, the meso‐MoO2/MoP‐NBs displays a remarkable cycling performance (515 mAh g−1 after 1000 cycles at 1 A g−1) and excellent rate capability (291 mAh g−1 at 8 A g−1). These findings can shed light on the behavior of the electron/ion regulation in heterostructures and provide a potential route to develop high‐performance lithium‐ion storage materials.

Keywords

• heterosturctures
• lithium‐ion batteries
• long‐term cycling stability
• MoO2/MoP