Crystallization and electrochemical properties of KxV2O5 nano-ribbons obtained via a solvothermal process as a promising cathode for PIBs

Abstract

In this research, a series of K⁺-intercalated quasi-1D vanadium-based nano-ribbons (K_xV₂O₅ NRs) were synthesized via a facile solvothermal method. The solvation and reductive effects of vanadium oxide precursors (V₂O₅ powder) on the crystallization and growth of K_xV₂O₅ NRs were studied. Besides, post-heat treatment was performed to improve the crystallinity of K_xV₂O₅ NRs. These K_xV₂O₅ NRs were adopted as active cathodes for potassium-ion batteries (PIBs), whose K⁺ storage properties were systematically evaluated using various electrochemical methods. The relationship among the morphology, crystallinity, working voltage window and electrochemical reversible K⁺ storage performance of K_xV₂O₅ NRs was studied and established. Results reveal that K_xV₂O₅-HG, which was prepared via a solvothermal reaction involving a solvation process (using H₂O₂) and a proper reducing condition (proper dose of glucose) with V₂O₅ powder as the raw material, would be more beneficial for the reversible storage of K⁺ when used as the cathode for PIBs compared to other contrast samples. In addition, the enhanced crystallinity and slightly broadened working voltage window of K_xV₂O₅-HG could hinder its long-term cycling stability upon repeated K⁺ insertions/extractions.