M_x V_2O_5A_y*nH_2O A HIGH-CAPACITY CATHODE MATERIAL FOR RECHARGEABLE LITHIUM BATTERIES

摘要

The aqueous synthesis and electrochemical properties of nanocrystalline V_2O_5*nH_2O (nominal composition) are described. It can be easily made in less than 1 hour by precipitation from acidified vanadate solutions, followed by drying. It has been characterized by X-ray powder diffraction, electron microscopy, TGA, chemical analyses, and electrochemical studies. The actual composition is M_xO_5A_y*nH_2O, where M is a cation from the starting vanadate salt and A is an anion from the mineral acid. This material exhibits high, reversible Li capacity and may be considered for use in a cathode in primary and secondary batteries. The reversible lithium capacity of an electrode composed of V_2O_5*nH_2O/EPDM/carbon (88/4/8 wt%) is ～ 380 mAh/g (C/80) and the energy density is ～ 1000 Wh/kg (120μm thick cathode, 4-1.5 V, versus Li metal anode).