Electrochemical properties of novel FeVO as an anode for Na-ion batteries.

Spinel based transition metal oxide - FeVO is applied as a novel anode for sodium-ion battery. The electrochemical tests indicate that FeVO is generally controlled by pseudo-capacitive process. Using cost-effective and eco-friendly aqueous based binders, Sodium-Carboxymethylcellulose/Styrene butadiene rubber, a highly stable capacity of ~97 mAh∙g is obtained after 200 cycles. This is attributed to the strong hydrogen bonding of carboxyl and hydroxyl groups indicating superior binding with the active material and current collector which is confirmed by the ex-situ cross-section images of the electrode. Meanwhile, only ~27 mAh∙g is provided by the electrode using poly(vinylidene difluoride) due to severe detachment of the electrode material from the Cu foil after 200 cycles. The obtained results provide an insight into the possible applications of FeVO as an anode material and the use of water-based binders to obtain highly stable electrochemical tests for sodium-ion battery.