Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10656865 | Electrochimica Acta | 2018 | 17 Pages |
Abstract
We have recently reported the reversible sodium intercalation in β-VOPO4 that has a moderate-high discharge plateau at 3.3â¯V vs. Na/Na+ and a theoretical capacity of 166â¯mAh gâ1. However, the practical applications of the cathodes are still impeded by the low electrical and ionic conductivities as seen in many metal polyanion cathodes. Herein, VOPO4/C and NaVOPO4/C composites have been prepared by ball-milling and tested in sodium ion batteries. X-ray diffraction and scanning electron microscopy confirm the phase is maintained after the ball-milling process, while the particle size is obviously reduced. Electrochemical tests show much improved capacities of 85â¯mAh gâ1 (â¼0.5 Na-ions per formula) at C/20. At a higher temperature of 45â¯Â°C, the discharge capacities are further increased to 130â¯mAh gâ1 and 115â¯mAh gâ1 for VOPO4/C and NaVOPO4/C (â¼0.78 Na-ions per formula for either) along with long-term cycling. The preliminary results suggest β-VOPO4 has the potential to exhibit good practical performance upon structural optimization. Thus, the exploration on the fabrication of nanoparticles and more efficient conductive coating will probably lead to more fruitful achievements.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Yang Ni, Guang He,