Facile synthesis of 3D urchin-like V6O13 microflowers as cathode materials for high-capacity and high-rate lithium-ion batteries

Abstract The development of three-dimensional nanomaterials with high specific surface area and stable structure is an important way to achieve excellent electrochemical performance. Here, urchin-like V6O13 microflowers are prepared through facile and controllable ion concentration regulation. In addition, by controlling concentration of oxalic acid, V6O13 nanobelts and V6O13 flowers are synthesized. Among them, urchin-like V6O13 microflowers electrode shows better electrochemical performance. Urchin-like V6O13 microflowers electrode exhibits an initial capacity of 375.7 mAh/g at 100 mA/g, higher than nanobelt V6O13 and V6O13 flowers electrodes with capacity of 348.2 and 334.2 mAh/g. Noted that urchin-like V6O13 microflowers electrode exhibits a capacity retention of 72.3 % after 50 cycles at 100 mA/g, while the capacity retention rates of V6O13 nanobelts and V6O13 flowers electrodes are 55.3 % and 67.5 %, respectively. The discharge capacity of urchin-like V6O13 microflowers electrode could maintain up to 138.8 mAh/g with a capacity retention of about 80.8 % after 100 cycles at 2000 mA/g, displaying a good cycling stability. The as-synthesized urchin-like V6O13 microflowers possess the multiple advantageous structural features, including large surface area, the nanosized building blocks and robust structure, which make it exhibits the excellent electrochemical performance in terms of large capacity and high rate as the cathode materials of lithium-ion batteries.