The performance of vanadium oxide nanorolls as cathode material in a rechargeable lithium battery

Vanadium oxide nanorolls have for the first time been successfully used as cathode material in a rechargeable lithium battery. The rolls consist of vanadium oxide sheets arranged in a scroll-like manner. The layers are separated by structure directing templates (e.g., primary amines) which can be readily exchanged by Various metal cations without destroying the tubular structure. X-ray diffraction (XRD) and transmission electron microscopy were used to investigate the morphology and structure of the rolls. Performance as an electrode material was tested by galvanostatic cycling in the potential range 1.8-3.5 V (vs. Li/Li+). The capacities were found to be closely dependent on the type-of lithium salt used in the electrolyte. Three salts were tested, LiBF4, LiPF6, and LiN(CF3SO2)(2). The imide salt, LiN(CF3SO2)(2), proved to give the best result with initial capacities >200 mAh/g. The material cycled reversibly for at least 100 cycles. XRD results indicate that the tubular structure is preserved even after prolonged cycling. (C) 2001 The Electrochemical Society.