Development of a high-performance anode for lithium ion batteries using novel ordered mesoporous tungsten oxide materials with high electrical conductivity

Abstract

An ordered mesoporous WO_3−X with high electrical conductivity (m-WO_3−X) was prepared and evaluated as an anode material for lithium ion batteries (LIBs). Ordered mesoporous tungsten trioxide (m-WO₃) with an identical pore structure to that of m-WO_3−X and bulk WO_3−X (b-WO_3−X) was prepared for the comparison purpose. An m-WO_3−X electrode exhibited a high reversible capacity (748 mAh g⁻¹, 6.5 Li/W) and a high volumetric capacity (∼1500 mAh cm⁻³), which is comparable to the Li metal itself (ca. 2000 mAh cm⁻³). Also, an improved rate capability and a good cyclability were observed in the m-WO_3−X electrode when compared with m-WO₃ and b-WO_3−X electrodes. From electrochemical impedance spectroscopy (EIS) analysis, the advanced anode performance of the m-WO_3−X electrode was probably attributed to large ordered mesopores and a high electrical conductivity. Differential scanning calorimetry (DSC) result displayed that the safety of m-WO_3−X was more improved than those of graphite and Si anode materials.