Novel Polygonal Vanadium Oxide Nanoscrolls as Stable Cathode for Lithium Storage

摘要

Scroll-shape structures with adjustable space provide interlayer sliding to accommodate the volume changes, which are promising candidates for increasing the stability of lithium batteries (LBs). In this work, for the first time, novel vanadium oxide polygonal nanoscrolls (PNSs) are synthesized in solution through self-rolling, Ostwald ripening, and scroll-by-scroll processes. The PNSs are of various shapes (including triangle, quadrangle, pentagon, and so forth) and spiral-wrapped multiwall. When evaluated as cathode for LB, the vanadium oxide PNSs cathode exhibits largely enhanced cycling stability (capacity retention of 91.7% after 150 cycles at 0.1 A g~(-1) in 2.0-4.0 V) compared with those of nonscrolled nanobelts (40.0%) and nano-wires (35.8%). Even at 1.0 A g~(-1), the PNSs cathode delivers high-rate long-life performance with capacity retention of 80.6% after 500 cycles. The unique polygonal nanoscroll structure is favorable for improving the cyclability and rate capability in energy storage applications as demonstrated here, and it will be interesting and has great potential for other related applications.