Template-free synthesis of ultra-large V2O5 nanosheets with exceptional small thickness for high-performance lithium-ion batteries

Similar to graphene, transition metal oxide nanosheets have attracted a lot of attention recently owning to their unique structural advantages, and demonstrated promising chemical and physical properties for various applications. However, the synthesis of transition metal oxide nanosheets with controlled size and thickness remains a great challenge for both fundamental study and applications. The present work demonstrates a facile solvothermal synthesis of ultra-large (over 1001Am) VO2(B) nanosheets with an exceptionally small thickness of only 2-5 nm corresponding to 3-8 layers of (001) planes. It can be readily transferred into V2O(5) with well retained nanosheet structures when calcined, which exhibit remarkable rate capability and great cycling stability. Specifically, the assynthesized vanadium pentoxide nanosheets deliver a specific discharge capacity of 141 mA h g(-1) at a current density of 0.1 A g(-1), which is 96% of its theoretical capacity (147 mA h g(-1)) for one Li + ion intercalation/removal per formular within a voltage window of 2.5-4 V. Even at an extreme-high current density of 5 A g 1, it still can exhibit a high specific discharge capacity of 106 mA h g 1. It is worthy to note that the V2O5 nanosheets electrode can retain 92.6% of the starting specific discharge capacity after 500 discharge/charge cycles at the current density of 1.5 A g(-1) (C) 2015 Published by Elsevier Ltd.