High Power Battery Electrodes Using Nanoporous V₂O₅/Carbon Composites

Abstract

Nanoporous composite electrodes for lithium ion batteries were successfully fabricated by coating porous carbon with V2O5 gel, and their high rate capability was demonstrated. The porous carbons prepared by using SiO2 colloidal crystals as templates exhibited ordered three dimensionally interconnected pores. The porous carbons were immersed in V2O5 sol under reduced pressure repeatedly to obtain V2O5/carbon composites. The nanoporous V2O5/carbon composites thus obtained exhibited large capacity of more than 100 mAh (g-composite)-1 and good rate capability of 80% at 5.0 A (g-composite)-1. The good performance is explained by electric double layer capacitance of large surface area and high rate lithium insertion to V2O5 gel. According to a calculation, very high-power energy sources with 177 mAh (g-composite)-1 at 100 A (g-composite)-1 are expected by using the nanoporous composite electrodes.