Novel Li3 VO4 Nanostructures Grown in Highly Efficient Microwave Irradiation Strategy and Their In-Situ Lithium Storage Mechanism.

Abstract

The investigation of novel growth mechanisms for electrodes and the understanding of their in situ energy storage mechanisms remains major challenges in rechargeable lithium‐ion batteries. Herein, a novel mechanism for the growth of high‐purity diversified Li3VO4 nanostructures (including hollow nanospheres, uniform nanoflowers, dispersed hollow nanocubes, and ultrafine nanowires) has been developed via a microwave irradiation strategy. In situ synchrotron X‐ray diffraction and in situ transmission electron microscope observations are applied to gain deep insight into the intermediate Li3+ x VO4 and Li3+ y VO4 phases during the lithiation/delithiation mechanism. The first‐principle calculations show that lithium ions migrate into the nanosphere wall rapidly along the (100) plane. Furthermore, the Li3VO4 hollow nanospheres deliver an outstanding reversible capacity (299.6 mAh g−1 after 100 cycles) and excellent cycling stability (a capacity retention of 99.0% after 500 cycles) at 200 mA g−1. The unique nanostructure offers a high specific surface area and short diffusion path, leading to fast thermal/kinetic reaction behavior, and preventing undesirable volume expansion during long‐term cycling.