Controlled formation of BNb3O9 nanobelts as superior host material for high performance electrochemical energy storage

Abstract

Ultra-stable anode materials for lithium-ion batteries are increasing in demand as highly sustainable energy storage system with excellent charge transport becomes unprecedentedly important. Here, a novel Li-ion full cell, utilizing BNb3O9 hollowed-out nanobelts as the typical intercalation anode and commercial LiFePO4 as the cathode in organic electrolyte, is reported. Moreover, the hollowed-out framework of BNb3O9 nanobelts, prepared by an adjustable-voltage electrospinning method, exhibits prominent cyclic stability (116.1 mAh g−1 at 700 mA g−1 (12C) over 1000 cycles) and outstanding rate capability (126.8 mAh g−1 at 900 mA g−1) in half cell. The key finding is that the formation mechanism of BNb3O9 hollowed-out nanobelts can be thoroughly discussed by scanning electron microscope. The contribution of the external pseudocapacitance largely affects the rate capability, which is determined via kinetic analysis. Furthermore, the lithium storage mechanism and structural evolution of BNb3O9 are investigated through in-situ X-ray diffraction. Such preeminent electrochemical performance and distinctive morphology endow BNb3O9 hollowed-out nanobelts with potentials as anode materials for lithium-ion batteries.