Cathode Materials Based on LiV3O8 Nanostructures for Sodium-Ion Batteries

In this work, nano LiV3O8(LVO) was synthesized using the rheological phase reaction method. Subsequently, after ultrasonic and heat treatment at 300 °C, the nano LVO Ut-300 was obtained and performed as cathode material in Na-ion batteries for the first time. Brunauer–Emmett–Teller analysis indicated that the specific area increased after ultrasonic treatment, which was conducive to the shuttling of sodium ions and enhancement of the electrochemical performance. The X-ray diffraction patterns displayed stable nano LVO Ut-300 material structure and larger interlayer spacing, and SEM and TEM performed more regular morphology. After the electrochemical tests, the nano LVO Ut-300 cathode delivered a high discharge capacity of 153.8 mA h g–1 in the voltage range of 1.8–4.0 V at 30 mA g–1. Meanwhile, the storage mechanism of Na+ was further explored by XPS, and kinetics characteristics of LVO/Na cells were revealed by pseudocapacitance analysis and galvanostatic intermittent titration technique (GITT) tests. In summary, nano LVO was processed by the ultrasonic method followed by subsequent heat treatment, which could effectively improve the electrochemical behavior of LiV3O8 as cathode materials of secondary Na-ion batteries.