Enhanced electrochemical properties of ball-milled γ′-V2O5 as cathode material for Na-ion batteries: A structural and kinetic investigation

JOURNAL OF POWER SOURCES

卷:482

Article

Baddour-Hadjean, Rita¹  Renard, Marianne Safrany¹  Pereira-Ramos, Jean-Pierre¹ 

[1] Univ Paris Est Creteil, Inst Chim & Mat Paris Est ICMPE, UMR 7182, CNRS, 2 Rue Henri Dunant, F-94320 Thiais, France

关键词: gamma '-V2O5;    Na-ion battery;    Cathode material;    Ball-milling;    Electrochemical properties;    Kinetics;   

DOI  :  10.1016/j.jpowsour.2020.229017

来源: Elsevier

【 摘 要 】

The recent intensive research for cathode materials beyond Li-ion batteries has revitalized interest in V2O5 due to its high reversible capacity. Among the various polymorphs, gamma'-V2O5 exhibits a unique corrugated layered structure that promotes the insertion of guest species. However, when used as cathode material for SIB, this material suffers from a 50% first charge efficiency that prevents the full benefit of its high discharge capacity of 140 mAh g(-1). Herein, we demonstrate and explain the effectiveness of a ball-milling approach to overcome this strong limitation. Several positive impacts of particle size reduction are highlighted: the charge efficiency is increased to 90%, allowing a 2-fold enhancement of the available capacity upon cycling (120 mAh g(-1) after 50 cycles at C/2). The Na insertion mechanism investigated by XRD and Raman spectroscopy shows a peculiar behavior with wide solid solution domains at the expense of the diphasic region. The kinetics study reveals a faster diffusivity in the ball-milled material and enhanced Na diffusion in the single-phase region. Both structural and kinetic reversibility account for the high performance here achieved for gamma'-V2O5: a high working voltage of 3.2 V vs Na+/Na, a high rate capability, excellent charge efficiency and good cycle life.

【 授权许可】

Free