PEG intercalated vanadium pentoxide xerogel for enhanced sodium storage

摘要

Vanadium pentoxide (V2O5) xerogel has attracted much attention as cathode materials for sodium-ion batteries (SIBs) due to its unique layered structure and high theoretical capacity. However, the poor cycling stability and sluggish kinetics severely hamper its practical application. Herein, polyethylene glycol (PEG) intercalated V2O5 xerogel (PEG-V2O5) is fabricated by a facile hydrothermal method. Compared to pure V2O5 xerogel, this PEG-V2O5 xerogel exhibits better cycling stability and enhanced rate capability. For example, the PEG-V2O5 remains a reversible capacity of 110 mAh g(-1) after 100 cycles at 100 mA g(-1), much higher than that (79 mAh g(-1)) of the pure V2O5 xerogel; the Na+ diffusion coefficient in PEG-V2O5 is more than two times of that in pure V2O5 xerogel. The expanded interlayer distance, stabilized layered structure, and excellent structure integrity account for enhanced sodium storage performance of the PEG intercalated V2O5 xerogel. This work provides clues for improving the sodium storage performance of V2O5 xerogel from the viewpoint of interlayer engineering. (C) 2020 Elsevier B.V. All rights reserved.