关键词: 钠离子电池, 正极材料, 钼钒氧化物, 碳复合, 纳米线

Abstract: In recent years, the development of lithium ion batteries (LIBs) has been limited due to the insufficient lithium resource and increasing cost. As a promising candidate, sodium ion batteries (SIBs) with the similar electrochemical mechanism and lower cost than LIBs are developing rapidly. However, as a result of the larger radius of Na⁺ compared with Li⁺, the crystalline structures of the most electrode materials are damaged severely during the intercalation of Na⁺, which limits the electrochemical properties of SIBs. Thus, developing new types of electrode materials for SIBs is particularly important. Among the cathode materials, the layered vanadium oxides are being widely studied. In this work, for the first time, we designed and synthesized a new type of carbon composited molybdenum doped vanadium oxide nanowires (MVO/C) with the excellent electrochemical performances. The highest capacity reached 135.9 mAh•g^-1under 50 mA•g^-1. After 75 cycles, there was still 82.6 mAh•g^-1 with 71.8% capacity remaining. When the current density was first increased to 1000 mA•g^-1 and then went back to 50 mA•g^-1, a high reversible capacity of 111.5 mAh•g^-1 was obtained. The results demonstrated that the new type of carbon composited molybdenum doped vanadium oxide nanowires with a ultra-high interlayer spacing is a promising material for sodium storage, providing a theoretical foundation for the further development of SIBs.

Key words: sodium ion batteries, cathode materials, molybdenum-vanadium oxides, carbon compositing, nanowires