Synthesis and electrochemical performance of NaV6O15 microflowers for lithium and sodium ion batteries

Abstract

Hierarchical NaV6O15 flower-like structures were successfully synthesized via a facile hydrothermal reaction combined with subsequent thermal transformation. The as-prepared NaV6O15 microflowers are composed of many nanoneedles with a width of about 200 nm and a length of several micrometers. The electrochemical performance of NaV6O15 microflowers as cathodes for both lithium and sodium ion batteries are investigated. High first discharge capacities of 255 mA h g-1 (vs. Li+/Li) and 130 mA h g-1 (vs. Na+/Na) are observed and the capacity retention reaches 105% and 64% after 50 cycles under 4-1.5 V at a current density of 100 mA g-1 and 50 mA g-1, respectively. High lithium/sodium ion diffusion coefficients play an important role in improving the electrochemical performance of NaV6O15 microflowers.